DEPARTMENT OF THE INTERIOR

ALBERT B. FALL, Secretary

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, Director 

Bulletin 708

HIGH-GRADE CLAYS OF THE EASTERN 

UNITED STATES

WITH NOTES ON SOME WESTERN CLAYS

BY

H. RIES, W. S. BAYLEY, AND OTHERS

WASHINGTON

GOVERNMENT PRINTING OFFICE

1922

CONTENTS.

PBKU.

Introduction__________________ _ _________ ___ . 1

Field work and acknowledgments__________ ____ __ 1

Imports of clay______________ ___________ 1

Statistics_______________________-______ 1.

Sources and kinds______________1______ 3

Exports of clay_____ _____ ___ __ 5

Statistics of production______ ___________________ 0

Requisite qualities of high-grade clays for different purposes 6

White-ware clays_________ ________________ G

Kaolins____________________________ 7

White-burning sedimentary clays__ __ 7

Ball clays______________________________ 9

Paper clays_________________________ - 10

Paint clays__________________________________ 11

Linoleum clays__ __________.___________ , _ 11

Refractory bond clays____ _____________ ___ 11

Deposits of high-grade clays______________________ ____ 15

Kaolins (white residual clays)________ _______ _ 15

Definition_________________________________ 15

General features_______________________ __ 15

Types of rocks that form kaolin ________________ 16

Need of purification for market__________________ 16

Distribution of kaolins in the United States_____..______ 16

Kaolin-bearing formations__ __________________ 1(5

Kaolins from pegmatites. _ _ _______ _ 17

Pennsylvania and Delaware___________________ 18

Maryland___________________________._.._ 18

Virginia____ _____ ___________________ 18

North Carolina, by W. S. Bayley________________ 18

Distribution of kaolin_ ______ _________ 18

Origin________________________________ 20

Variation in completeness of kaolinization________ 22

Refining and by-products _________________ 23

Composition _______ _________________ 25

Kaolins in the mountain region_______________ 26

Occurrence ___-____________________ 26

Character of the pegmatites _____________ 26

Kaolin mines _______________________ 27

Dillsboro, Jackson County_____________ 28

Hog Rock mine _____________ 28

Roda mine____________________ 30

Woodrow, Haywood County___________ 31

Mine of the Hand Clay Co. (Inc.)_____ 31
IV CONTENTS.

Deposits of high-grade clays Continued.

Kaolins (white residual clays)- Continued. 

Kaolins from pegmatites Continued. 

North Carolina Continued.

Kaolins in the mountain region Continued.

Kaolin mines Continued. Page.

Micaville, Yancey County______-_ 35

AVilson mine________ 35

Wyatt mine __________ - 35

Toecane, Yancey County_____ 36

Job Thomas mine___ _ 36

Pit of the Clay Products Co_ 36

Sprucepine, Mitchell County __ 36

Sprucepine mine- ____-_ 36

Sparks mine 39

Franklin, Macon County___-__ 41

Porter property ________T __ _ 41

Johnston' property-___-___ _ 42

Cunningliam property ______ _ 42

lotla mine_________________ 43

Almond, Swain County______________ 44

Hewitt mine__________________ 44

Bryson, Swain County_______ _ 44

Payne & Sullivan mine____________ 44

Harris mine________________-_ 46

Penlancl, Mitchell County____________ 47

Property of the Bailey Lumber Co_ __ 47

Undeveloped deposits___________ _ _ 52

Franklin, Macon County_______________ 52

. McGuire property _______________ 53

Fergnson property-____________ 54

Dillsboro, Jackson County__________:_ 55

Property of the Harris Kaolin Co_____ 55

Beta, Jackson County_______________ 55

Rqss property_______..________ 55

Etowah, Hericlerson County____________ 57

Valentine property __________ _ 57

Hazelwood, Haywood County__________ 58

Herren property________________ 58

Birdtown, Swain County _____________ 59

Cole & Black property____________ 59

Micaville, Yancey County___________ 60

Thoinas prospect _______________ 60

Smith prospect ________________ 61

Mitchell County__________________ 61

Jefferson, Ashe County ______________ 64

Bare property_________________ 64

Kaolins in the Piedmont Plateau region__________ 65

Kaolins from pegmatite and granite_________ 65

Bessemer City, Gaston County__________ . 65

Property of J. A. Smith___________ 65

Lincolnton, Lincoln County_____________ 67

Mine of the United States Tin Co_____ 67
CONTENTS. V

Deposits of high-grade clays Continuetl.

Kaolins (white residual clays) Continued. 

Kaolins from pegmatites Continued. 

North Carolina Continued.

Kaolins in the Piedmont Plateau region Continued. Pago.

Kaolins from schistose rocks (partly pegmatites)--- 68

Troy, Montgomery County _ 68

Mount Gilead, Montgomery County____ 69

Property of P. M. Eames___ --_ 69

Overton, Montgomery County____ __ 69

Property of A. J. Overton_________ 69

Catawba, Catawba County___ ___ 70

Property of E. A. Ervin________:_..___ 70

Statesville, Iredell County____________ 71

Property of Cashion & Furchess______ 71

Bosticks Mills, Richmond County________ 72

Property of R. L. Steele__________ 72

Kaolin reserves of North Carolina_____________ 7,r>

Prospecting foi' kaolin _________ ______ 77

Uses of kaolins of North Carolina____ ____ 78

South Carolina, by W. S. Bayley________________ 79

Abbeville County _____ 79

Georgia _________________________________ 82

Alabama__________________ __________ 82

Kaolin from Cambrian schists in Pennsylvania_________.__ 82

Glen Loch, Delaware County_-______________._ 82

.South Mountain region, Cumberland County_________ 83

General features of the deposits________ ____ 83

Property of the Cumberland Clay Co_-___-_____ 85

Property of the Philadelphia Clay Co__________ S-">

Property of the Sandusky Portland Cement Co_____ 85

Henry Clay mine ______________1 _ _- 86

Property of the Holly Clay Corporation __... 86

Beavertown ___________________________ 88

Uses of the kaolins from the South Mountain region 89

Future of the region_______________ ___- 89

Narvon, Lancaster County_____________________ 89

Pit of the Whittaker Clay Co_______________ 90

Pit of the Diller Clay Co___________________ 90

Uses of the clays from Narvon______________ 91

Honeybrook, Chester County__________________ 91

Kaolin from Cambrian quartzite in central Pennsylvania, by

E. S. Moore__"__ __________________________ 92

Geologic occurrence-_________________-_____ 92

Distribution of the clays______________________ 94.

Mines and prospects_______________________ 94

Blair property-_________________________ 94

Colonial Clay Co _______________________ 95

Patton property ________________________ 96

Dungarviu station_______________________ 97

Woodbury Clay Co______________________ 98

Possibilities of future development______________ 98

Uses of the kaolins from central Pennsylvania________ 98

Kaolin from feldspathic quartz!te in Connecticut_________ 99
VI CONTENTS.

Deposits of high-grade clays Continued.

Kaolins (white residual clays) Continued. Page.

Xaolin from Cambrian shale in Virginia______________ 99

Lipscomb, Augusta County___-________________ 100

Cold Spring, Augusta County__________________ 101

Lofton, Augusta County_____________ ____ 102

Vesuvius, Augusta County____________________ 103

Buena Vista, Rockbridge County________________ 104

Kaolins from Cambrian limestone in Missouri__________ 104

General features of the deposits________________ 104

Property of American China Clay Co_____________ 107

Bausch mine ____________________________ 108

Kaolins from shales and limestones of the Oriskany group in the

Appalachian States _________________________ 108

Occurrence and distribution___f ______________ _____ 108

Pennsylvania____________________________ 109

Saylorsburg district______________________ 109

Geology, by F. B. Peck_________________ 109

Character and uses of the clays- _______ 111

Mines___________________________ 111

Mine of the Keystone Clay & Reduction Co__ 111

Property of the Mount Eaton Clay Co_____ 112

Property of the Atlas Portland Cement Co__ 113

Kunkletown, Monroe County_________________ 114

Petersburg, Huntingdon County____ ________ 115

Shirleysburg, Huntingdon County______________ 115

Hollidaysburg, Blair, County________________ 116

West Virginia and Virginia____________________ 117

Hampshire County, W. Va., and Frederick County, Va__ 117

Lignite, Botetourt County, Va________________ 117

Notes on occurrences of kaolin west of the Mississippi_____ 120

Arkansas ____ ___________ _______________ 120

Bauxite!_____________..______________ ..__ 120

Little Rock___________..______________ 120

Nevada, by J. P. Buwalda__..._______________ 121

Oreana________________________ 121

Pitt-Rowland mine_____________________ 121

Lovelocks ___________________________ 122

Adamson-Dickson property______________ 122

Telluride____________________________ 124

Shepard property _______ __ 124

Kiernan property_____________________ 125

Beatty______________________________ 125

Bond & Marks deposit_________________ 125

Idaho______________________..__________ 126

California_____________.__________________ 126

Antioch_______________________________ 126

Summary ____________________________________ 126

Kaolin mining and refining__ ________ _____ _ 127

^ Residual clays of undetermined derivation _ _ 128

Alabama _____________________.._____________ 128

Fort Payne, Dekalb County________ _________ 128

Bynum, Calhoun County____:_____ ________ 130
CONTENTS. VII

Deposits of high-grade clays Continued.

Residual clays of undetermined derivation Continued. Page.

Clays of Carboniferous age (chiefly sedimentary) 131

St. Louis district, Mo___I_____________ __ 131

Glass-pot clays in Ohio, by Wilbur Stout-_______ 133

Pennsylvania____ - 135

Flint clays of central Missouri-___________________.._ 135

Occurrence and distribution____.___________ 135

Character of the clays_____ __ _ _ * 338

Grades of clay shipped _ __ __ 140

Future of the district ..__________ _ 140

Details of the flint-clay pits_________________ 140

Hofflin, Crawford County________________ 140

Owensville, Gasconade County________ _ 141

Connell pit______________________ 141

Sassman pit________________ - 142

Rosebud, Gasconade County.-______..______ 144

Brown pit________________ _ 144

fiauers & Watkius pit_______-__..______ 144

Heidel & Toelke pit______________.._ 144

Bland, Gasconade County.. .___.. __. __ -. 145

. Shockley pit_________________________ 145

Campbell & Lichte pit_________________ 145

Canaan, Gasconade County____________ _ 146

Belle, Maries County____________________ 147

Indianaite of Indiana_________. _______________ __ 147

General features of the deposits, by W. N. Logan___^____ 147

Geographic distribution_____________________ 147

Geologic occurrence________^_______________ 149

Character of the outcrop_____________________ 150

General character of the clay_ ______________ 150

Associated rocks__________________________ 152

Resources of indianaite_____________________ 154

The deposit of indianaite near Huron, Lawrence County, Ind.,

by H. Ries_______________________________ 154

Structure of the beds _ __________________ 154

Physical character of the clay_________________ 156

Petrographic character_____..________________ 156

Relations of the clay to the rocks associated with it________ 158

Theories of origin___________ ________________ 159

Combustion of coal bed______________________ 159

Alteration of limestone______________________ 159

Deposits of residual clay _ _________________ 160

Igneous intrusion___________ _____________- 160

Vein deposits____________________________ 160

Sedimentary deposits. ___ _________________ 161

Biochemical reactions ______________________ 161

Replacement of quartz pebbles _______________ 161

^ Sedimentary clays of the Coastal Plain and the Embayment Area,__ 162

Geologic relations _ _ _______ 162

Methods of mining ___ ________ ____ 163
VIII CONTENTS.

Deposits of high-grade clays Continued.

Sedimentary clays of the Coastal Plain and the Embayment Area Con. pa?n.

Lower Cretaceous clays________________________ 164

South Carolina, by W. S. Bayleyl_______________ 164

The clay-bearing formations________________ 164

The clay beds________________________ 166

Pits in Lower Cretaceous clays_____________ 168

Bath, Aiken County_______________:___ 168

Prgperty of the McNamee Kaolin Co______ 368

Langley, Aiken County__________________ 171

Property of the South Carolina Clay CoJ___ 171

Property of the Paragon Kaolin Co_______ 174

Property of the Peerless Clay Co______ 177

Property of the Immaculate Kaolin Co____- 182

Dixiana, Lexington County____________ 385

Geiger property __________________ 185

Trenton, Edgefield County_______________ 185

Minis property_____________ 185

Uses of the Cretaceous clays of South Carolina___ ___ 186

. Varieties of clay______________________ 186

Paper________________________ 387

Pigments_________________________ 188

Floor and wall tile___________________ 189

Pottery_______1_____________ __ 189

Filler ____________________._____ 190

Miscellaneous uses________________ 190

Defects and their remedy_____ _ - 190

Conditions that affect operation___1___________ 191

\ Location _______________ 191

Overburden______i__________ 192

Economic problems__________________ 193

Future development of the white clays of South Carolina 194

Georgia _________._______________________ 194

Distribution_____________-__________________ 194

Origin _______________________________ 195

Mode of occurrence___'____________ 195

Structure___________________________ 196

Variation in the clay_____________________ 196

Chemical and physical properties _____ _ 197

Minerals___________________________ 197

Overburden ____________________________ 198

The white-clay industry___________________ 198

Future expansion_______________________ 200

Uses of the white clays of Georgia____________ 200

Maryland ______________________________ 201

Arundel - formation__________,___________ 201

Patapsco formation_____________________ 201

Upper Cretaceous clays_________________________ 202

Raritan formation ____________,_____________ 202

New Jersey _________________________ 202

Occurrence and distribution_______________ 202

Uses of the clays of New Jersey, by G. H. Brown_ 203

Maryland _____________________________ 204
CONTENTS. IX

Deposits of high-grade clays Continued.

Sedimentary clays of the Coastal Plain and the Embayment Area Con.

Upper Cretaceous clays Continued. - Page.

Tuscaloosa formation____________________ 204

Alabama ___________________________ 204

Mississippi _____________________!______ 205

Distribution and character. .. 205

Undeveloped properties in Tishomingo County, by

E. N. Lowe ___________________._____ 206

Tishomingo __'___________________ 206

luka_________________________ 206

Golden________________________ 209

Eastport _______________________ 209

Middendorf arkose member of Black Creek formation in

South Carolina______________________.__ 211

Warrenville, Aiken County______________ 211

Property of Parker Kaolin Co______ - 211

RayfUn, Lexington County____ ______ 213

Property of Edisto Kaolin Co__________ 213

Horrell Hill, Richlaml County-_____________ 215

Property of Interstate Clay Co___ __ 215

Property of Columbia Mineral Products Co___ 219

Aiken, Aiken County__________________ _ 220

Property of Render-son Bros__-___ 220

Society Hill, Chesterfield County -*.____________ 222

Coker property_______________ 222

Eutaw formation__________________________ 222

Selma chalk____________________________ 222

Ripley formation__________________________ 223

Distribution and character_______________ 223

Georg'a _____________________________ 224

Tennessee___________________________ 225

Hollow Rock, Can-oil County______________ 225

India, Henry County__________________ 229

Tertiary clays________________________________ 230

Distribution________,._____________________ 230

Eocene (?) clay__________________________ 230

South Carolina, by. W. S. Bayley_______________ 230

Abbeville, Abbeville County______________ 230

Midway group ____________________________ 233

Georgia _____________________________ 233

Mississippi____________________________ 235

Tennessee, Kentucky, and Illinois_____________ 236

Distribution and character______________ 23G

Ben ton, Marshall County, Ky______________ 236

Briensburg, Marshall County, Ky_______.___ 238

Murray, Galloway County, Ky_______1____ 238

Wilcox group___________________________ 238

Distribution ___________________________ 238

Georgia _ _______________________ 239

Mississippi ________:___________________ 239

Distribution and character____ __________ 239

Clays of Ackerman formation_____________ 240
X CONTENTS.

Deposits of high-grade clays Continued.

Sedimentary clays of the Coastal Plain and the Embayment Area Con 

Tertiary clays Continued. 

Wilcox group Continued.

Mississippi Continued. Page.

Clays of Holly Springs sand_____________ 240

Clays of Grenada formation _.._. _________ 242

Distribution and character____________ 242

Pits of J. T. Bramlett______________ 243

Property of McLendon Clay Co_________ 246

Pits of Mitchell Clay Co_____________ 247

Property of Southern Ball Clay Co_______ 247

Charleston, Tallahatchie County________ 248

Future of the clays of the Grenada forn>ation__ 248

Undeveloped properties, by E. N. Lowe_______ 249

Clays of Grenada formation___________ 249

Tocowa, Panola County___________ 249

Charleston, Tallahatchie County______ 250

Carrollton, Carroll Coimty_________ 250

Clays of Holly Springs sand___________ 252

Hudsonville, Marshall County_______ 252

Laiuar, Benton County____________ 253

Oxford, Lafayette County__________ 253

Arkansas____________________________ 255

Distribution and character_ ____________ 255

Mines _____________________________ 256

Lester, Ouachita County_____________ 256

Benton, Saline County______________ 259

Lagrange formation _ _-_ _ ___ ________ 259

Correlation and character______________. ___ 259

Tennessee ___________________________ 260

Distribution and character_:____________ 260

Localities ________________________ 261

General features of the mines__________ 261

La Grange, Fayette County..__________ 262

J. F. Dale sand pit-. . _ - 262

McNanee pit ___.._______________ 263

Pinson, Mad son County______________ 263

McKenzie, Carroll County____.._______ 264

Johnson-Porter Clay Co___________ 264

C. S. Sparks pit________________ 266

Henry, Henry County ________________ 267

Whitlock, Henry County_____________ 269

Pits of Mandle Clay Mining Co______ 269

Puryear, Henry County_____ _ __ 272

Property of Dixie Brick & Tile Co_____ 272

Property of Cooley Ball & Sagger Clay Co.. 272

Uses of Lagrange clays of Tennessee ___ 275

Kentucky ___________________________ 276

Occurrence and distribution______________ 276

Pryorsburg, Graves County_____'____________ 276

Property of Kentucky Construction & Improvement Co________________________ 277 

Pit of Mayfleld Clay Co______________ 279
ILLUSTRATIONS. XI

Deposits of high-grade clays Continued.

Sedimentary clays of the Coastal Plain and the Embayment Area Cori. 

Tertiary clays Continued.

Lagrange for mation Continued.

Kentucky Continued. Page.

Hickory Grove, Graves County____________ 280

Pit of Old Hickory Clay & Talc Co_______ 280

Pit of Colonial Clay Co______________ 281

Pit of National Sales Co______________ 281

Wickliffe, Ballard County_______________ 282

LaClede-Christy Clay Co_____________ 282

American Clay Co_________________ 282

Undeveloped Lagrange clays in Kentucky_____ 282

Uses of Lagrange clays of Kentucky.. ____ 283

Illinois___________..______________. 284

Distribution and occurrence_____________ 284

Character and uses of the clays______________ 285

Oligocene clays__ ______________ _______ 289

Florida _________-__-______-____ __ - 289

Distribution and character________________ 289

Uses of clays of Florida__ _______^ __ 291

Microscopic study of clays, by R. E. Sorners_________________ 292

Method of examination _____________ ____ _______ 292

Identification and character of minerals __________________ 29G

Quartz_________________-___ ____-_____- 296

Kaolinite__________'_________ __ _______ 296

Hydromica_____________________ _____ 296

Comparative abundance of kaolinite and hydromicas ___ 297

Halloysite________________________________ 298

Rutile________________<_____-______,_____- 298

Rare minerals______ ___ __ 299

Diaspore.l____________-_____ _______- 299

Gibbsite______________-_____________________ 299

Texture______________________________________ 300

Minerals in the burned clay__ . _____ 300

Previous work on burned clay _____ ______ 304

ILLUSTRATIONS.

PLATE I. Map of western North Carolina showing location of kaolin deposits ________ _______ _______________ 18

II. Panoramic view of Hand mine, Wooclrow, N. C______,__ 32 

III. A, Wall of pit of Gurney Clay Co., near Franklin, N. C.; B,

Pit No. 1 of Payne & Sullivan mine, Bryson, N. C_____ .- 33

IV. A, Pit of Holly Clay Corporation, Mount Holly Springs, Pa.; 

B, Shaft of Mount Eaton Clay. Co., southwest of Saylorsburg, Pa_____________________________ 86

V. A, Whittaker residual clay pit, Narvon, Pa.; B. Residual clay

from Cambrian clayey sandstone, Dungarvin, Pa_______ 87 

VI. A, Pit of Product Sales Co., Cold Spring, Augusta County, 

Va.; B, Shallow shaft and hoisting drum at kaolin mine 

near Lutesville, Mo ___....________________...._ 102
XII ILLUSTRATIONS.

«

Page.

VII. A, Cox flint-clay pit north of Hofflin, Mo.; B, Sassman flintclay pit, Owensville, Mo_ ___ 103

VIII. A, Bauers & Watkins flint-clay pit, Rosebud, Mo.; B, Flint

clay in Toelke & Heidel pit, Rosebud, Mo 144

I.. Indianaite attached to pebbly Pottsville sandstone 145

X. Map of Southeastern States showing distribution of Cretaceous

and Tertiary formations carrying high-grade clays_'. ___'. ___ 162

XI. Map of South Carolina showing distribution of Cretaceous

clay-bearing formations and clay mines____-________ 164

XII. A, Unconformity between drab clay and white sand in pit of 

Paragon Clay Co., Langley, S. C.; B, Pit of Peerless Clay 

Co., south of Langley, S. C________________ 174

XIII. Map of part of Georgia showing location of clay mines and

prospects ______ _________ _ 194

XIV. A, Clay bank of Columbia Kaolin & Aluminum Co., 4 miles 

south of Gordon, Ga.; B. Jointed structure in clay shown 

above the track level in A._:_________1 _ 196 

XV. A, Pit of Georgia Kaolin Co., near Dry Branch, Ga.; B, Pit of 

Republic Mining & Manufacturing Co., east of Andersouville, 

Ga ___________;______________________ 197

XVI. Pit of Edgar Bros. Co., near Mclntyre, Ga__________ 198

XVII. Map of western Kentucky and Tennessee showing distribution

of clay deposits__________________________ 226 

XA^III. A, Section in pit of Paducah Clay Co., Briensburg, Ky.; B,

Clay pit of J. T. Bramlett, 10 miles west of Enid, Miss__ 238

XIX. A, Gullies near Huutington, Tenn., showing natural exposures 

of Lagrange clays; B, Typical section of gravelly overburden, often called "Lafayette"___________________ 239

XX. Columnar sections of Lagrange formation of western Tennes-'

see and Kentucky_________________________ 260 

XXI. A, McNanee clay pit, La Grange, Term.; B, J. F. Dale sand pit,

La Grange, Tenn__________,_____________ 262 

XXII. Sagger clay pit of Scales-Reynolds Clay Co., south of Henry,

Tenn__________ ^____________________. 263

XXIII. A, Near A'iew of face in Dalton pit of Johnson-Porter Clay

Co., near McKenxie, Tenn.; B, View in pit of Cooley Ball 

& Sagger Clay Co., in Henry County, Tenn., 8 miles northwest of Puryear_______"__________________ 264

XXIV. A, Pit of Mandle Clay Mining Co., Whitlock, Tenn.; B, Williams pit of Johnson-Porter Clay Co., near McKenzie, Tenn_ 265

XXV. A, Working face of pit of Kentucky Construction & Improvement Co., Pryorsburg, Ky.; B, Pit of Edgar Plastic Kaolin 

Co., Edgar, Fla_________________________.__ 278

XXVI. A, Shaft house and storage shed at Gants mine, near Mountain 

Glen, Union County, 111.; B, Old pit of Illinois Kaolin Co., 

near Mountain Glen, Union County, 111___________ 279

XXVII. Photomicrographs of specimens of clay: A, " Worm" of 

kaolinite from Bauxite, Ark.; B, Grain of tourmaline surrounded by grains of kaoliuite and hydromica from 

Narvon, Pa _______________:____________ 296 

XXVIII. Photomicrographs of specimens of clay: A, Oolite of diaspore 

from flint clay at Rosebud, Mo.; B, Spherulite of koalinite (?) in white clay from Huron, IncU____________ 297
ILLUSTRATIONS. XIII

Page.

XXIX. Photomicrographs of specimens of clay: A, Clay from PittRowland mine, Oreana, Nev.; B, Kaolin from Mount Holly 

Springs, Pa_______________: _____________ 300

XXX. Photomicrographs of specimens of clay: A, Residual clay 

from Beatty, Nev.; B, AVhite sedimentary clay from 

Florida_________________________________ 301 

FIGUBE 1. Relations of kaolin and country rock in north wall of tunnel

in pit No. 2 of the Payne & Sullivan mine, Bryson, N. C_ 46

2. Relations of kaolin to mica schist at end of crosscut in a pit

in the Payne & Sullivan mine, Bryson, N. C________ 46

3. Map of kaolin deposits near Bryson, N. C____________ 47

4. Map of borings at Penland mine, Penland, N. C_ _ 49

5. Map of borings on the "Firescald " property, owned by I. C.

Bailey, near Penland, N. C_________ , - 51

6. Map of kaolin deposits near Franklin, N. C_ - ___ 52

7. Map of borings on Ferguson property near Franklin, N. C__ 54

8. Map of. kaolin deposits near Dillsboro, N. C ____ ___ 56

9. Herreu pit, Hazel wood, N. C.: A, Vertical wall of pit; B,

Cross section of pit_______________________ 59

10. Map of kaolin deposits in Mitchell, Yancey, and Avery counties, N. C________________________________ 62

11. Longitudinal section of kaolin deposit near Bessemer City,

N. C_______________________________.._ - 66

12. Relations of kaolin in deposit owned by Cashion & Furchess,

Statesville, N. C_________________________ 71

13. Section in west side of cut in road 2$ miles south of Abbeville,

S. C _______'_________________________ 80

14. Map showing clay mines in South Mountain district, Pa___ 84

15. Map showing clay pits in Narvon district, Pa__________ 89

16. Map showing residual clay deposits in Huntingdon, Blair, and

Center counties, Pa________________________ 92

17. Map showing location of shafts in white residual clay in

Saylorsburg district, Pa _____________________ 110

18. Map showing flint-clay pits in central Missouri________ 137

19. Plan of Connell flint-clay pit, Owensville, Mo ;_______ 141

20. Section along line A-B in plan of Connell flint-clay pit

(fig. 19) ___..___________ ____________ 142

21. Section in Sassman flint-clay, Owensville, Mo___ ______ 143

22. Section in Charles Brown flint-clay pit, 2i miles southwest of

Rosebud, Mo ______________________________ 144

23. Plan of Heidel £ Toelke pit, Rosebud, Mo___________ 145

24. Map of part of Indiana, showing area that may contain

indianaite________________________________ 148

25. Neck of clay projecting into indianaite in the Gardner mine,

near Huron, Ind__________________________ 150

26. Section along north side of second cross entry, on east side

of tunnel in the Gardner mine, near Huron, Ind_______ 152

27. White indianaite (clay) overlying sandstone, vein of indianaite crossing the sandstone, and fin of sandstone extending upward into the indianaite in the Gardner mine, near 

Huron, Ind ____________________ .____..__ 153
XIV ILLUSTBATIONS.

Page.

28. Angular pieces of pebbly sandstone completely surrounded by 

white clay in wall of crosscut about 50 feet from entrance 

of tunnel in the Gardner mine, near Huron, Ind_______ 155

29. Indianaite overlying sandstone and vein of indianaite extending into the sandstone in the Gardner mine, near Huron, Ind_ 155

30. Section showing unconformity in pit of McNamee Kaolin Co.

near Bath, S. C __________________________ 108

31. Section in pit of South Carolina Clay Co. south of Langley,

S. C ___________________________"_____ 172

32. Section in pit of Paragon Kaolin Co. south of Langley, S. C 174

33. Columnar sections in the Rlpley and Porters Creek formations

of western Tennessee and Kentucky______________ 226

34. Section on south side of pit of Paducah Clay Co., east of

Briensburg,. Ky_ _______________________'_ 238

35. Section through Wilcox clays and sands in northwestern

Mississippi_______________________________ 240

36. Section along Sherman Creek 4 miles north of Crevi, Miss., on

property of Southern Ball Clay Co _ _______ 247

37. Map of region northwest of Lester, Ark., showing location of

clay mines- _ 257

38. Sections of deposit of Illinois Kaolin Co. near Mountain Glen,

111___________________________________ 285
HIGH-GKADE CLAYS OF THE EASTEBN UNITED STATES 

WITH NOTES ON SOME WESTERN CLAYS,

By H. RIES, W. S. BAYLEY, and others.

INTRODUCTION. 

FIELD WORK AND ACKNOWLEDGMENTS.

The field work required for the preparation of this report was 

clone in the summer of 1918. Most of the worked deposits of the 

types of clay discussed in this report in Pennsylvania, Virginia, 

Florida, Alabama, Mississippi, Tennessee, Kentucky, Illinois, 

Arkansas, and parts of Missouri and Georgia were visited, but 

time was not available for detailed geologic mapping, much of which 

has already been done by the United States Geological Survey and 

State surveys.

In all the States visited the State geologists cooperated most cordially. Thanks are also due to the clay-mining companies for similar 

cooperation and for many courtesies.

The States of North Carolina and South Carolina were visited by 

W. S. Bayley, whose report is included in this bulletin, as are also 

some separate descriptions, by W. N. Logan, of the white clays of 

Indiana; by E. S. Moore, of the Cambrian, residual clays of central 

Pennsylvania; by F. B. Peck, of the residual clays of the Oriskany 

of eastern Pennsylvania; by G. H. Brown, of the clays of New JerseJ I by Wilbur Stout, of the glass-pot clays of Ohio; and by J. P. 

Buwalda, of some clays of Nevada. Thanks for assistance are also 

due to Dr. A. V. Bleininger, of the Bureau of Standards; Prof. 

C. W. Parmelee, of the University of Illinois; C. R. Schroyer, of 

the Illinois Geological 'Survey; M. E. Wilson, of the Missouri Geological Survey; Prof. E. S. Moore, of the Pennsylvania State 

College; Dr. E.. R. Hice, then State geologist of Pennsylvania; and 

Prof. F. B. Peck, of Lafayette College. The petrographic work for 

the report was done by Dr. R. E. Somers.

IMPORTS OF CLAY.

STATISTICS.

Prior to the beginning of the war, in 1914, the United States had 

been a large importer of certain high-grade clays, which were used 

in the manufacture of white-ware pottery, floor and wall tile, electrical porcelain, paper, graphite crucibles, glass refractories, linoleum, 

paint, and other products. Some idea of the extensive use of these

1
HIGH-GKADE CLAYS OF THE EASTEBN 'UNITED STATES.

foreign clays in the domestic industry may be gained from the figures 

shoAving the imports for the years 1907-1920, published by the 

United States Geological Survey.

Clay imported and entered for consumption in the United States, 1907-1920.

Year.

1907..

1908.

1909.

1910.

1911.

1912.

1913.

1914.

1915.

1916.

1917.

1918.

1919.

1920.

Kaolin or china clay.

Quantity 

(short

tons).

239,923

176, 895

246. 381

257,902

255, 107

278, 276

268,666

328,038

209, 132

253,707

241, 029

168, 100

180,592

361, 800

Value.

$1,582,893

1, 129, 847

1, 505, 779

1,593,472

1, 461, 068

1,629,105

1,623,993

1,927,425

1,152,778

1,326,684

1,315,769

1,153,240

1,965,393

3,568,677

Average 

price

Tjer 

ton.

S6.60

6.39

6.11

6.18

5.73

5.85

6.04

5.88

5.51

5.22

5.46

6.86

10.88

9,86

Common blue

and Gross-Almerode glasspot clay.

Quantity 

(short

tons).

12,378

4,872

12, 346

21, 176

17, 193

23, 112

24,986

16, 761

8,864

2,501

88

114

4

6,837

Value.

8110,686

37,053

104,401

181,334

124, 278

184,018

204,911

122, 325

62,569

12, 134

709

983

133

157,201

0 All other clays.

Umvrought.

Quantity 

(short

tons).

31,196

27, 730

30, 147

27,890

26,086

32,473

42,582

50,069

23,718

42,478

26,581

26,984

23, 759

34, 252

Value.

3145,698

129,411

134,978

113,352

100, 540

127,004

155,693

195,956

90,367

163, 421

123,439

163, 484

187, 550

272, 524

Wrought.

Quantity 

(short

tons).

2,520

1,372

1,906

1,496

1,032

794

1,889

3,232

1,343

180

338

137

498

691

Value.

$81, 155

22, 990

50,632

26,205

10, 436

12, 109

22, 178

41, 712

12, 433

1,994

2,142

1,087

4,262

10, 267

Total.

Quantity 

(Fhort

tons).

286,017

219,869

290, 780

308, 464

299,418

334,655

338, 123

398, 100

243,057

298, 866

268,036

195, 335

.204, 853

403,580

Value.

$1,920,432

1, 319, 301

1,795,790

1, 914. 363

1,696,322

1,952,236

2, 006, 775

2,287,418

1,318,147

1. 504, 233

1,442,059

1, 318, 794

2, 157, 338

4,008,669

This table shows that the chief foreign clay used in this countryis English kaolin or china clay, which in 1920 represented nearly 90 

per cent of the quantity and value of all the clay imported.

Until 1917 the strong movement of foreign clays to the United 

States continued, but with the entry of this country into the war 

the possibility increased that the importation of clay might be shut 

off, or at least reduced, owing to scarcity of ships, and so a real 

anxiety arose in the clay-using industries lest there should be a 

deficiency of clay for making those kinds of ware whose production 

had depended on a supply of foreign raw material. Not all the 

industries that used imported clays relied on them exclusively, but 

some did, and others relied on them to a large degree. Indeed, some 

manufacturers claimed that it was impossible to get along without 

a supply of imported raw material.

The following estimate, compiled by the United States Shipping 

Board, shows the quantity of English china clay required by the 

United States in 1918.

English china clay required by the clay-working industry of the United States

in 1918.

Long tons.

Porcelain and electrical____________________ 20,000 

Paper filler ___________________________ 112,000 

Paper coating___________.__ J____________ 30,000 

China ___________________________ 50,000 

Oilcloth, cotton filler, and bleaching_____________ 12,000 

Sanitary ware and tile_____________________ 25,000 

Ultramarine and paint_____________________ 2,000
IMPORTS OF CLAY. 3

The quantities stated in the estimate for paper filler and for paper 

coating are probably too low.

When it became evident that shipments of clay from foreign countries might be curtailed, the problem was presented whether similar 

classes of clay now produced in the United States could be obtained 

in sufficient quantity to meet a considerably increased demand and 

whether those industries which had hitherto relied wholly or in 

part on foreign materials could not draw more largely on domestic 

sources of supply. Strictly speaking, therefore, this report deals 

with only those types of clay that had been imported; others are not 

considered unless they are closely associated with those that claim 

our particular attention.

On the whole, the facts concerning the domestic supply shown by 

this investigation, some of which have already been made public,1 

are most encouraging.

Though it is difficult and even unsafe to make any definite calculations of the quantity of clay in the domestic deposits, except where 

many test-hole records are available, it is nevertheless possible to 

form a reasonably safe estimate of the probable reserves of many 

deposits, or at least to state whether they are large or small.

SOURCES AND KINDS.

Most of the clays imported prior to 1914 were obtained from 

England and Germany. Those imported from England were chieiiy 

kaolins and ball clays; indeed, England has supplied not only the 

United States but certain European countries that have not sufficient 

supplies of their own, such as Germany, France, .Holland, Denmark, 

and Italy. The English kaolins were used not only by domestic 

manufacturers of vitrified and unverified clay wares but by makers 

of paper^ paint, linoleum, ultramarine, and other products. The 

English ball clays were used in making the burned-clay wares mentioned above and also to some extent in making glass pots, crucibles, 

and abrasive wheels.

The type of clay that was most largely imported from Germany 

is that known as refractory bond clay, which is used in the manufacture of glass pots, crucibles, and abrasive wheels. According to 

the reports of the United States Bureau of Foreign and Domestic 

Commerce, the imports of German clays into the United States in 

1914 amounted to 22,062 tons and in 1915 to 12,057 tons. The chief 

German clays included in these imports were the Gross,Almerode 

clay, which was used extensively in making glass pots, and the

1 Ries, H., The occurrence of high-grade American clays, and the possibility of their 

further development: Am. Ceramic Soc. Jour., vol. 1, No. 7, 1918.

77412 22 2
4 HIGH-GRADE CLAYS OF THE EASTERN "UNITED STATES.

Klingenberg clay, which was much employed by manufacturers of 

graphite crucibles. .A third. German clay that was widely used, 

though in smaller amounts, was the Vallendar clay, which was 

employed as an ingredient of enamels. A fourth German clay was 

the Scheppach refractory bond clay.

At the beginning of the war the exportation of the German clays 

had to stop, and that of the English clays was decreased. This 

decrease of imports at first caused considerable uneasiness among 

consumers, although some of them had rather large stocks of foreign 

clays, but it had the beneficial effect of increasing the consumption 

of domestic clays, and the increase might have been even greater had 

there been sufficient labor to mine the clay and cars to carry it to the 

points of consumption. Nevertheless, many manufacturers did use 

a larger quantity of domestic clays, and the clay-mining industry was 

thus stimulated. Then there arose a discussion as to the extent to 

which foreign clays were really needed in the domestic industries, 

and right at the beginning some strong differences of opinion were 

expressed.

In preparing this report the senior author has conferred with 

several clay technologists and corresponded with a large number of 

producers, and in addition he has ascertained as far as possible the 

regular purchasers of clay from every pit visited. From the data 

so obtained the conclusions given below have been drawn.

1. The industries that now use English clays but that in time may 

be able to dispense with them are those that manufacture vitrified 

tableware and sanitary ware, hard-fire porcelain, chemical porcelain, and linoleum. Some firms that make these products have 

already ceased to use the English claj^s, but the'manufacturers of 

certain grades of vitreous ware at least have not yet found it possible to substitute American clays completely for imported ones. 

One objection that is made to some of the domestic clays is their lack 

of uniformity, and this is a fault that the domestic producers should 

strive to correct. Greater loss in firing is another objection made 

to American clays, but there seems to be a difference of opinion as to 

whether the trouble really lies in the clay or whether the manufacturers have not yet discovered the proper mixture of domestic 

materials and the best conditions of treatment.

Linoleum manufacturers claim that English china clay has greater 

uniformity of composition, better color, and more opacity than 

domestic clay.

Most paper manufacturers claim that English clay is necessary for 

coating because it has better color and spreads better, but that 

domestic clay to the extent of about 10 per cent can be mixed with it.

2. The industries that need only a small quantity of English clay 

are those that manufacture electrical porcelain and paper. The
EXPORTS OF CLAY. 5

makers of electrical porcelain could dispense with English ball clay 

and could cut out half of the English china clay they use. Some 

manufacturers of electrical porcelain use only domestic clays. One 

objection urged against American clays is that they are not uniform. 

Many manufacturers of paper say that English clay is not needed 

for filler, but it seems to be needed for coating.

3. The industries that need no English clay are those that manufacture white earthenware and floor and wall tile.

The industries numbered 1 to 3 need no other foreign clay than 

that mentioned.

4. The industries that probably need no foreign clay whatever are 

those that manufacture glass pots, graphite crucibles, abrasive wheels, 

pencils, and paint (?).

All consumers and even all technologists may not agree concerning 

the requirements stated in the above grouping. The manufacturer 

naturally objects to changing a mixture that he has long been using.

For some years manufacturers of glass refractories have been using 

a considerable quantity of washed clay from the St. Louis district 

in their glass-pot mixtures and have also drawn upon the German 

pot clay, just as the crucible manufacturers have used the imported 

Klingenberg clay. When the supply of German clays was shut off 

domestic bond clays had to be sought, and they are now in use.

The makers of glass refractories seem to be successfully using 

domestic clays, but the makers of crucibles, or some of them, at least, 

complain that a mixture composed entirely of American clays does 

not stand as many heats as the old combination. This trouble, 

however, may be due to the fact that the proper combination has not 

yet been fully worked out.

EXPORTS OF CLAY.

Although the United States has imported a considerable quantity 

of clay, it has, during the last few years at least, also exported 

a considerable quantity, as the following figures will show:

Clay exported from the United States, 1916-1920.

Year.

1916...........................

1917...........................

1918...........................

1919...........................

1920. ..........................

Fire clay.

Quantity 

(short 

tons).

45, 752 

54,023. 

60,206 

37,486 

54,125

Value.

$144, 552 

268, 093 

333, 880 

262, 501 

393, 177

All other.

Quantity 

(short 

tons).

27, 941 

29, 194 

24,348 

56,983 

66, 035

Value.

$145,970 

178, 764 

192,053 

249, 571 

775, 222

Total.

Quantity 

(short 

tons).

73,693 

83,217 

84,554 

68, 469 

120, 160

Value.

$290,522 

446,857 

525,933 

512,072 

1,168,399
6 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

At least nine-tenths of the clay exported was sent to Canada, and 

the remainder was sent to Europe, South America, Central America, 

Asia, and Oceania.

STATISTICS OF PRODUCTION.

Some conception of the demands of the country for certain grades 

of domestic clay may be obtained from the following table. These 

quantities added to the imports less the exports give the total consumption. The classification in this table is not strictly exact, however,.for it includes, under fire clay, grades that are not considered 

in this report. One prominent American potter says that the potters 

of the United States use in their mixtures from 35 to 40 per cent of 

American kaolin and from 25 to 50 per cent of domestic ball clay.

Domestic clay marketed in the United* States, 1918-1920.

Year.

1913..

1914..

1915..

1916..

1917.. 

1918.. 

19191 

1920o

Kaolin.

Quantity 

(short

tons).

28,834

34,191

28,031

47,723

31,885 

37,969 

39,000 

6264,000

Year.

1913........

1914........

1915........

1916........

1917........

1918........

1920o......

Value.

$235,457

284,817

241, 520

308, 819

301,378 

391, 109 

427,000 

62,385,000

Paper clay.

Quantity 

(short

. tons).

126,377

116, 328

113,033

153,434

174,449 

141, 725 

148,000

(6)

Stoneware clay.

Quantity 

(short

tons).

153,353

130,383

134,297

135,958

81,352

86,800

65,000

90,000

Value.

$143,587

116,610

126,429

137, 779

113,839

147,098

137,000

250,000

Value.

$567,977

558, 334

539,622

768,911

962, 421 

1,068,420 

1,221,000

Slip clay.

Quantity 

(short

tons).

10,902

8,237

7,646

14, 084

16,972 

13,552 

3,000 

10,009

Brick clay.

Quantity 

(short

tons).

158,890

199, 154

101,968

97, 164

93.779

i ( c )

<«)

Value.

$137,976

161,852

93.863

76,854

94 703

(c)

(0

Value.

$24,505

17,731

18,774

47,939

70,505 

49,898 

12,000 

49,000

Ball clay.

Quantity 

(short

tons).

67, 134

67,927

75,348

89,761

107,406 

89,896 

93,000 

145,000

Value.

$237,672

255,767

301,910

391, 152

569,240 

590,631 

637,000 

1,340,000

Miscellaneous clay.

Quantity 

(short

tons).

282, 120

244,173

332, 150

336,672

260,029

301, 386

300,000

250,000

Value.

$240,694

214,180

288,341

314,311

305,365

421,421

500,000

350,000

Fire clay.

Quantity 

(short

1,820,379

1,409,467

1,570,481

2,057,814

2,347,972 

2,305,033 

1,715,000 

2,400,000

Value.

$2, 592. 591

2,147,277

2,361,482

3,708,009

5,625.095 

5,664,064 

4,143,000 

7,720,000

Total.

Quantity 

(short

tons).

2,647,989

2,209,860

2,362,954

2, 932, 590

3,113,844

2,976,361

2.363,000

3,159,000

Value.

$1,180,459

3,756,568

3,971,941

5,751,774

8, 042, 546

8,332,641

7,077,000

12,094,000

a Estimated.

6 Paper clay included under " Kaolin."

c Included under "Miscellaneous clay."

REQUISITE QUALITIES OF HIGH-GRADE CLAYS FOR 

DIFFERENT PURPOSES.

WHITE-WARE CI/AYS.

The white-ware clays include the kaolins and ball clays and white- 

 burning sedimentary clays which are used in white ware, including 

pottery, electrical goods, and floor and wall tile, whether vitrified or 

porous.
QUALITIES OF HIGH-GRADE CLAYS.

KAOLINS.

The kaolins include those white residual clays which burn white 

or nearly so and are of refractory nature and more or less porous 

after burning. Their plasticity is usually lower than that of the 

sedimentary clays, and they have to be washed before shipment to 

market. The necessity of washing this material with care can not 

be emphasized too strongly; the high reputation of English kaolins 

for uniformity is due to better preparation than that made in 

America.

Chemical analyses of kaolin, though not of much practical value, 

show that most of them contain a low percentage of impurities, that 

some approach rather closely to kaolinite in composition, and that 

they may have much the same composition whatever the nature of 

the parent rock. The influence of the parent rock is shown perhaps 

chiefly in differences in the content of silica.

Analyses of kaoUns.

Silica................ ................................

Ferric oxide. ........................................

Lime. ...............................................

Potash ..............................................

1

45. 78

36.46

.28

l.OS

.50

.04

1 25

/ ""

13.40

2.05

99.84

2

46. 50

37.40

.80

Trace.

1.1

12. 49

98.29

3

72.30

18.94

.40

.68

.39

.42

7.04

99. 57

4

48. 26

37.64

.46

.06

1. uO

12.02

100. 00

5

43. 31

 <Q 49

2.86

.04

/ .25

1 W\

13. 58

99.76

1. Washed kaolin. Webster, N. C., derived from pegmatite. North Carolina Gool. Survey Bull. 12, p. 

62,1897.

2. Washed kaolin, West Cornwall, Conn., derived from feldspathie quartzUe.

3. Crude kaolin, Glen Alien, Mo., derived from cherty dolomite. Missouri Geol. Survey, vol. 11. p. 

562,1896.

4. Washed kaolin, Cornwall, England, derived from granite. U. S. Geol. Survey Prof. Paper 11, p. 

39, 1903.

5. Crude kaolin, Cold Spring, Va., derived from Cambrian shale. Analysis supplied by Virginia Geol. 

Survey.

Of the kaolins listed in the table only Nos. 1 and 4 are regularly 

used in the manufacture of white ware. No. 5 does not burn quite 

white enough, but a small amount of it can be used in a white body 

without seriously affecting the color.

The true kaolins used regularly in the manufacture of white ware 

come chiefly from North Carolina and Delaware.

WHITE-BURNING SEDIMENTARY CLAYS.

In the trade the white-burning sedimentary clays are known as 

kaolins, plastic kaolins, sedimentary kaolins, and secondary kaolins. 

Certain white sedimentary clays, like those found in Georgia and 

South Carolina, are also used in white wares. They are incorrectly
HIGH-GEADE CLAYS OF THE EASTEEN UNITED STATES.

spoken of as kaolins, and some potters seek to differentiate them from 

the white residual clays by calling them sedimentary kaolins.

Most of these clays are smooth, and some of them, like those of 

Georgia and South Carolina, may yield comparatively little residue 

on washing, but others, like those of Florida, carry a large proportion of sand. Few of them^burn quite as white as the best true 

kaolins, and in plasticity they stand intermediate between the true 

kaolins and the ball clays. They closely resemble the residual kaolins 

in composition, but usually have higher shrinkage. According to 

the testimony of many manufacturers the one class can not be substituted, pound for pound, for the other.

The following tests and analyses give some of the characters of 

Georgia white sedimentary clay :

Analyses of white sedimentary clay from Georgia.

Silica (SiO?) .........................................................................

Soda (Na2 0).. .......................................................................

Potash (KZ 0) .......................................................................

Sulphur (S) .....................:..-................................................

Loss at 100° C. ......................................................................

1

44.76

38.41

.63

.20

.09

.09

.35

1.37

13.46

1.22

100. 58

2

44.25

38.06

1.03

.08

Trace.

.10

.70

1.29

.06

13.63

.38

99.58

1. Dry Branch, Ga.

2. Gordon, Ga. Schurecht, H. G., Am. Ceramic Soc. Trans., vol. 19, p. 248,1917.

Drying and shrinkage tests of white sedimentary clay.

.

Washed Georgia clay..................... ... .. ... ..................

Drying 

shrinkage.

2.32

4.38

Fire 

shrinkage, 

cone 1.

4.48

8.12

Tests of clay from Gordon, Ga., shouting shrinkage and porosity in firing.a

Temperature 

CO.).

1, 210 

1,250 

' 1, 290 

1,330 

1,370 

1,410

Porosity (per 

cent).

29.45 

28.33 

31.02 

34.15 

28. 53 

22. 78

Volume shrinkage (percent).

36.01 

33.05 

32.88 

31.10 

36.05 

40.40

o Schurecht, H. G., Am. Ceramic Soc. Trans., vol. 19, p. 248, 1917.

The white sedimentary clays of Georgia and South Carolina are 

being used more in pottery than formerly. However, as is pointed
QUALITIES OF HIGH-GEADE CLAYS. 9

out by Watts,2 they can not be indiscriminately substituted for other 

white-burning clays on account of differences in physical character. 

Results of tests of clays from South Carolina in porcelain bodies 

are given on pages 170-184.

BAI,L CLAYS.

The term ball clays is applied to clays of good plasticity, strong 

bonding power, and high refractoriness, which burn white or 

creamy white and are used in mixtures employed for making white 

ware to give the mixtures greater plasticity, to strengthen their bond, 

and to increase their density after firing. They are used chiefly in 

making white earthenware and porcelain but are also used in making 

floor and wall tile. Some of these clays are used in the manufacture 

of glass refractories and crucibles.

The supply of ball clay was formerly obtained from England, but 

large quantities are now obtained from western Kentucky and Tennessee. The total quantity reported by these two States in 1918 was 

58,140 short tons, valued at $265,325. -

The white-burning clay of Florida, which is called by some a ball 

clay, is really intermediate between the ball clays of Kentucky and 

Tennessee and the sedimentary clays of the belt that traverses 

Georgia and South Carolina.

The following results of chemical analyses of some ball clays are 

given for those who may be interested in their composition. The 

results of physical tests of ball clays are given.on pages 13 and 281.

Analyses of ball clays.

Silica (SiOj). .............................................................

Alumina (A12 03 ) .........................................................

Titanic oxide (TiOn).. . ...................................................

Lime (CaO) ..............................................................

Potash (K^O). ............................................... ^............

Soda (Na2 0). .............................................................

Moisture at 100°C. ........................................................

1

46.85

33.15

2.04

.35

.40

.61

.10

.03

16.45

99.98

2

48.99

32.11

2.34

.43

.22

o. ol

9.63

97. OJ

3

46.67

36.58

1.14

.43

.50

Trace.

\ 1.60

.06

11.52

1.60

100. £0

1. Whitlock, Tenn.

2. England.

3. Mayfleld, Ky.

2 Watts, A. S., Comparison of American china clays as porcelain Ingredients: Am. 

Ceramic Soc. Jour., vol. 2, p. 151, 1919.
10 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

PAPER CLAYS.

Clay is used by the paper manufacturer as a filler, for coating, and 

in wall paper as a base for color applied to the surface. For all these 

purposes the clay must be free from grit, for grit cuts the wire of the 

screens and scratches the surface of the calendar rolls. It should also 

disintegrate readily. White clay is invariably selected, but the color 

may not have to be quite so carefully watched in clay for filler as in 

clay for coating. A third essential property is that the clay shall be 

retained by the pulp, a point that has to be determined by practical 

test. Whiteness and fineness, however, are of prime importance.

The domestic clays most used are the white sedimentary clays of 

Georgia and South Carolina, although the \vhite residual clays of the 

Mount Holly Springs and the Saylorsburg district of Pennsylvania 

have been used to a lesser extent. More recently the white residual 

clay of Cold Spring, Va., has been employed for filler.

A canvass among the producers and consumers shows that most of 

the white clay from Georgia and South Carolina is sold, for use in 

paper. Some manufacturers state, furthermore, that it is being used 

as a substitute for English clay; others state that it can not be so used. 

Curiously enough, some producers of the same class of paper express 

opposite opinions concerning the same clay.

According to Roe,3 there has been a recent tendency to develop 

American clays for use in making paper. He writes:

For many years there was a distinct prejudice in most quarters against local 

clays, it being claimed that the English article is of better color, contains less 

grit, and possesses to a higher degree those qualities which are peculiarly essential in a coating clay. As far as color is concerned, domestic clays tend to a 

yellow tone whereas the imported article is more of a blue white. It is a fact, 

however, that some, of the higher grades of English clay are artificially colored 

with a blue coal-tar dye, which undoubtedly accounts for the superior color. 

In some cases ultramarine has been used for the purpose. This pigment is unstable under conditions which might easily obtain in paper making, in which 

cases the color imparted would fade. While the average English clay is better 

in color than the average American clay, some of the domestic clays now on the 

market are of good color and are admitted in most quarters to be quite satisfactory for filling purposes.

He further states that the domestic clays as formerly marketed 

carried too much grit, but that they have been geatly improved in 

this respect. For coating, however, the English clay is almost universally preferred.

"Roe, R. B., Clays for use in paper making: Am. Ceramic Soc. Jour., vol. 2, p. 69, 

1919.
QUALITIES OF HIGH-GRADE CLAYS. 11

%

PAINT CLAYS.

Manufacturers of paint demand in general a white gritless plastic 

clay, which is used to mix with the colors. In general the material 

required is similar to that demanded by the paper makers, although 

the requirements as to minute differences in shades of color and grit 

would seem not to be quite as severe, although one manufacturer 

states that the clay should pass a 300-mesh sieve. Low moisture content is also demanded. However, irregularity in product is seriously objected to, and clay miners should give heed to this fact. 

Domestic clays used in paints are obtained in general from the same 

districts as the paper clays.

LINOLEUM CLAYS.

White clays are used for making linoleum. In addition to whiteness, they must possess opacity, freedom from grit, and proper 

plasticity. The additioil of talc to the clay is claimed by some to 

increase its opacity. Clays also differ in the quantity of linseed oil 

required to mix them with the color, and it is said that English clays 

take less oil than American clays. Absolute uniformity of standard 

is highly essential. The South Carolina white sedimentary clays 

and some of the domestic kaolins are employed to some extent in

making linoleum.

REFRACTORY BOND CLAYS.

The refractory bond clays include those clays which have refractoriness and bonding power that makes them of value for glass 

refractories, for crucibles to melt steel and brass, and to a less extent 

for the bond of abrasive wheels.

In considering the properties of refractory bond clays, attention 

must be given both to the properties that exist in the clays in their 

ra\y condition and to the properties that are developed in the clay 

by burning.

The characteristic properties of the raw clays are their transverse 

strength, especially if mixed with an equal amount of sand, and the 

ratio of pore water to shrinkage water. Bleininger 4 suggests that 

clays may be divided into two classes the first class including those 

whose modulus of rupture is 325 pounds to the,square inch or more, 

and those whose modulus of rupture is between 225 and 325 pounds. 

The ratio of pore water to shrinkage water should not exceed 1.00

* Bleininger, A. V., and Loomis, G. A., The properties of some American bond clays: 

Am. Ceramic Soc. Trans., vol. 19, p. 601, 1917.
12 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

for clays of the first class. For strong, heavy, plastic clays, low 

in free silica, the ratio should not exceed 0.75, but siliceous bond 

clays, such as the Gross Almerode, can not meet this requirement.

The principal criteria of the value of the clay as determined by 

burning are the overfiring temperature and the softening point. For 

very severe service the clay should not develop a definite vesicular 

structure below 1,425° C. nor a softening point below cone 31 

(1,750° C.); but, as Bleininger says, this specification may not be 

fair to some plastic clays that are of use in the manufacture of 

graphite crucibles, especially for brass melting, although even for 

this purpose the temperature of overfiring should not be much below 

1,400° C. and the softening temperature not much below that of 

cone 30 (1,730° C.). Anything below these requirements should be 

ruled out as a bond clay.

To grade these clays, then, according to their uses, Bleininger suggests the following classification:

1. Clays particularly suited to manufacture of graphite crucibles 

used for melting brass., Should burn dense at 1,150° C. and show no 

evidence of overfiring at 1,400° C. and have other required physical 

properties.

2. Clays adapted for crucibles for steel melting. Should burn 

dense around 1,275° C. and not overfire at 1,400° C. or higher.

2a. Clays like those of class 2 but that do not overfire below 1,425° 

C. These clays are valuable in addition for making glass refractories.

3. Clays especially suited to glass.industries. Should burn dense 

only at 1,425° C., or even higher, and not overfire below 1,450° C.

Clays that become dense between 1,150° and 1,300° C. and that 

overfire at or just above the temperature at which they become dense 

are of no value as refractory bond clays.

The following table by Bleininger and Loomis shows the characteristic physical properties of a number of good refractory bond clays, 

as well as some that are deficient in refractoriness:
QUALITIES OF HIGH-GRADE CLAYS.

1

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14 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

A number of interesting tests of crucible clays mixed with graphite 

have been made by M. C. Booze,5 from which he concludes that no one 

clay satisfies to a high degree all the requirements for crucibles. 

Indeed, some of these requirements are so diametrically opposite 

that no one clay is entirely satisfactory. By selecting the clays that 

rank higher than the others in all or most of the requisite properties, 

using them as a base, and blending them with others, it is possible 

to get a mixture that gives better results than any one clay alone 

would yield.

The domestic clays used in the manufacture of glass pots and 

crucibles are obtained chiefly from the Wilcox group of northwestern 

Mississippi and the Lagrange formation of Tennessee, Kentucky, and 

Illinois, from the Carboniferous clays of the St. Louis district in 

Missouri, and from the Portsmouth district in Ohio. Some clay for 

glass pots has been obtained from deposists at Lowell, 111.,6 and in 

the Woodbridge district of New Jersey. The deposits near Lester, 

Ark., which occur in the Wilcox formation, have not been worked 

for at least two years, and there is no steady production from the 

locality near Contee, Md.

6 Booze, M. C., Some properties of bond clays for graphite crucibles: Am. Ceramic Soc. 

Jour., vol. 2, p.-461, 1919.

"Lines, E. H., Pencsylvauinu fire cl'ays of Illinois: Illinois Geol. Survey Bull. 80, p. 73, 

1937.
DEPOSITS OF HIGH-GRADE CLAYS.

KAOLINS (WHITE RESIDUAL CLAYS).

DEFINITION.

The term kaolin is properly applied only to a white residual clay 

that is the product of weathering, though kaolinization may occasionally be caused by other processes,7, but by many the term is 

somewhat loosely used to mean any clay that burns white or nearly 

Avhite, including white clays of sedimentary origin. This practice 

is unfortunate, for the uses of these two classes of white clay are 

somewhat different.

GENERAL FEATURES.

Residual clays may be formed by the weathering of many different 

kinds of rock. The depth of the deposit depends on the extent to 

which weathering .has penetrated the rock and the thickness of material that has been removed during the period of weathering or since 

the clay was formed. The depth to which weathering may penetrate 

the rock is determined by the permeability of the rock, the resistance 

of the minerals composing the rock, and by the depth to water level. 

'We can not assume, therefore, that weathering will extend to the 

same depth in all kinds of rock or- at all places. Even in the same 

formation weathering may reach to great depth at one locality but 

not at another. (See pp. 22-23.)

The shape of a deposit of residual clay will be governed largely 

by the shape of the parent rock the rock from which it is derived. 

Thus a pegmatite dike will yield a deposit that is relatively long but 

narrow, whereas a horizontally bedded deposit or a mass of granite 

may yield a deposit that is of considerable horizontal extent as compared with its depth.

The color is likewise dependent on features of the parent rock. 

If the parent rock contains few or no particles of iron-bearing minerals, which liberate iron oxides during the process of weathering, 

.the residual clay is white, but if the parent rock contains many particles of iron-bearing silicates or ferruginous impurities the clay is 

likely to be more or less strongly colored. Residual clays may therefore range in color from snow white to an intense red or brown, 

caused by iron. Indeed, different parts of the same rock mass will

7 Ries, II., Origin of kaolin: Am. Ceramic Soc. Trans., vol. 13, p. 51, 1911.

15
16 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

yield different-colored residual clays, which may lie side by side but 

be separated by sharp boundaries. In pits in residual limonitb 

(brown iron ore) it is not uncommon to find lenses of white clay 

completely surrounded by brilliantly colored material.

TYPES OF BOCKS THAT FORM KAOLIN.

The true kaolins are not derived exclusively from feldspathic rocks. 

The deposits in the United States have been formed from syenite, 

granite, pegmatite, rhyolite, arkose, schists, shales, limestone, and 

feldspathic quartzite. The hydrous aluminum silicates in clay derived from the first six of these types of rock are produced chiefly 

by the decomposition of the feldspar; those in the shales, limestones, 

and quartzites are probably present in the parent rock.

NEED OF PURIFICATION FOR MARKET. .

The parent rock of most kaolins contains considerable quartz, and 

some of it contains much mica, and as these minerals are regarded as 

undesirable impurities the kaolin is commonly washed in order to 

eliminate them as far as possible. Some kaolins present no special 

difficulty in washing, but others (such as the kaolin from Mount 

Holly Springs, Pa.) contain sand which is so finely divided that it 

tends to float off with the clay in the process of washing. By adding 

an electrolyte like sodium carbonate the clay is deflocculated and the 

silica settles out more completely. This method of treatment appears 

to work better with residual than with sedimentary clays. The 

quartz and mica are sometimes sold as by-products.

DISTRIBUTION OF KAOLINS IN THE UNITED STATES.

Kaolin deposits are rare in the glaciated area. Outside of this 

area they are somewhat widely distributed, at least in the eastern 

half of. the United States, but the number of commercially valuable 

deposits is comparatively small. Moreover, the physical qualities 

of those already developed differ considerably, so that they are not 

all useful for the same purpose. Nor do they all occur in the same 

geologic formation.

KAOLIN-BEARING FORMATIONS.

All the kaolins found in the United States are probably of comparatively recent geologic age, but the age of the rocks from which 

they have been derived differs in different places.

Beginning in the northeast, there is an isolated deposit near West 

Cornwall, Conn., which is derived from a feldspathic quartzite. 

Small bodies o'f kaolin have been reported from western Vermont 

and yield a small output annually.
KAOLINS (WHITE RESIDUAL CLAYS). 17

Next there are the kaolins derived from pegmatite in Delaware 

 and Chester counties, Pa., which were extensively worked in former 

years, though their production has now fallen off greatly owing to 

the exhaustion of the deposits. Similar deposits are still worked 

in the State of Delaware.

Two other formations that yield kaolin in Pennsylvania are (1) 

the Devonian shales and cherty limestones, which are worked near 

Saylorsburg, Monroe County, and which supply residual clays farther west in the State, though all the material is not pure white, 

and (2) the Cambrian schists, which contain kaolin in the South 

Mountain district o.f Cumberland County, -as well as farther west in 

Huntingdon County.

In Cecil County, Md., a small deposit of kaolin derived by decomposition from a granodiorite has been worked at different times.

In Hampshire County, W. Va.; and adjoining portions of Virginia 

white and grayish-white residual clays occur-in shales and sandstones of the Oriskany group.

Along the western slope of the Blue Ridge in Virginia the Cambrian shale yields white residual clays, but the known kaolins of the 

Piedmont area-in that State have not proved to be valuable.

The western counties of North Carolina have long produced 

kaolins. The material was formed from pegmatite veins, but similar rocks in Georgia and Alabama have yielded little thus far.

In the Central States the only deposits of kaolin known are those, 

derived from limestone in Missouri, and some of doubtful value ih 

Wisconsin from schist and in Arkansas-from syenite.

Some scattered deposits of unique character in Nevada and Idaho 

derived from limestone in Missouri, and some of doubtful value in 

California. One of doubtful origin and remote from the railway 

is known in Texas, as well as some small deposits in Colorado.

In the following descriptions the deposits are grouped according 

to the type of rock from which they are derived.

KAOLINS FROM PEGMATITES.

The purity of the crude clay depends on the mineral character of 

the parent rock. Where weathering has been complete all the feldspar is generally changed to clay. The impurities, which occur in 

varying amounts, are quartz and muscovite mica. Tourmaline in 

blocklike lumps or crystals and beryl are also found in some deposits. Garnet, if present in the original rock, is usually decayed to 

ferruginous spots. Other impurities may occur in small amounts. 

Rutile is almost invariably present, but the grains are so small that 

they can be seen only with the microscope. In the kaolins of North 

Carolina Bayley notes the occasional presence of lumps of iron or 

manganese oxide.
18 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES. 

PENNSYLVANIA AND DELAWARE.

Kaolin derived from the weathering of pegmatite veins was formerly worked near Kaolin, Chester County, and Brandy wine Summit, Delaware County, but the mines are no longer in operation.8 

Similar deposits were worked at Hockessin, Del., and are still being 

operated near Newark, Del.

MARYLAND.

Kaolin occurs in Cecil County," but the production has not been 

very large nor steady. The clay has been used in china and in paper. 

According to tests made by the Bureau of Standards, the mixture of 

clays employed for making porcelain glass pots may contain about 24 

per cent of this clay.

VIRGINIA.

The Piedmont province of Virginia contains a few deposits of 

kaolin, all derived from pegmatite by weathering, but none of them 

have proved to be of economic value, chiefly because their area, so far 

as known, is small, or because the quantity of washed product obtainable is small.

Some years ago attempts were made to work a deposit of kaolin 

near Roseland, in Nelson County, but the venture was unsuccessful, 

and the plant has been dismantled. Another deposit was formerly 

operated near Patrick, in Henry County.10

NORTH CAROLINA.

By W. S. BAYLEY. 

DISTRIBUTION OF KAOLIN.

The kaolins of North Carolina occur west of the " fall line," which 

runs along the east side of Warren County and south westward to the 

State line near Buckingham, Eichinond County. (See PI. I.) There 

are some white clays east of this line, but most of them are impure, 

and hence they can not be used for the same purposes as the kaolins 

so they are not discussed here.

The part of the State that lies west of the " fall line " is separable 

into two main physiographic divisions the Piedmont Plateau to 

the east and the Appalachian Mountain area to the west. The line 

dividing these provinces (see PL I) is at the base of the Blue Ridge 

and passes diagonally through the State from the west side'of Surry

8 Hopkins, T. C., Clays of southeastern Pennsylvania (in part) : Pennsylvania State 

Coll. Ann. Rept. for 1898-99, Appendix, p. 29, 1900.

8 Riea, H.,. Report on the clays of Maryland : Maryland Geol. Survey, vol. 4, pt. 3, 

.1902. Cecil County report, Maryland Geol. Survey, p. 211, 1902.

10 Ries, H., and Somers, R. B., Clays of the Piedmont province, Va.: Virginia Geol. 

Survey Bull. 13, 1917.
KAOLINS (WHITE RESIDUAL CLAYS). 19

County, southwestward to the center of Polk County. A small area 

of the Coastal Plain co,vers parts of Richmond, Anson, and Montgomery counties, but this is somewhat broken by outliers of the Piedmont Plateau.

The mountain area is characterized by strong relief. It comprises 

mountain chains, broad plateaus, and deep, narrow valleys.

The plateaus \vere formed by long weathering and denudation, 

and it is at places on their surfaces where the weathering has been 

deepest that the best deposits of kaolin occur. The areas along the 

main streams have been reduced to nearly level plains, which have 

been cut into by the streams to depths of 100 to 300 feet. In these 

areas the rocks are deeply decomposed, and where they contained 

much feldspar deposits of kaolin have been formed. Unfortunately, 

however, most of these deposits are buried under surficial material 

and can not be found.

The Piedmont Plateau which lies east of the mountains is characterized by low, rounded hills, which are separated by broad, shallow valleys. Here all the rocks are deeply decayed, but the slope of 

the hills is so low that much of the product of decay has been left 

on the surface. Thus materials derived from different sources have 

been intermingled, and the entire surface is covered with a deep 

mantle of mixed detritus that obscures the underlying rocks, so that 

narrow belts of kaolin produced by the decomposition of pegmatite 

dikes are difficult to locate. Where feldspathic grain.ites or other 

feldspathic rocks occur over large areas, however, the deposits of 

kaolin may be so extensive that their presence may be revealed at 

the surface. Because of its striking appearance, the kaolin, even 

when much mixed with other materials, may easily be recognized. 

Indeed, the kaolin at the surface generally covers a much larger area 

than that beneath, and where kaolin outcrops on a slope, its creep 

or wash downhill may also tend to increase the apparent area of the 

deposit. Deposits of kaolin derived from pegmatites are generally 

more valuable than those derived from other feldspathic rocks, which 

usually . contain much undesirable material. A few deposits of 

kaolin occur on the Piedmont Plateau in North Carolina, but the 

most promising ones are in the mountain area.

Deposits of clay are found also along the river valleys. Large quantities of the products of rock weathering have been transported from 

the upper courses of the streams and have been spread over the flood 

plains in the lower courses. Many of the rivers in North Carolina 

flow through districts where there is much kaolin, which they have 

brought down in large quantities and deposited, with other material, 

on their flood plains. Some of these deposits contain many minerals 

besides kaolinite; they consist of an impure clay which is not suited 

77412 22 3
20 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

to the purposes for which the purer kaolin is employed, and they are 

therefore mentioned only incidentally in this report. Much of this 

clay may be used in making stoneware, but most of it is too impure 

even for this use.

The high-grade kaolins of North Carolina ma}^ for convenience in 

classification, be separated into two groups those of the mountainous 

district and those of the Piedmont Plateau. Only the clays of the 

mountains have been developed commercially. '

ORIGIN.

The kaolins of North Carolina have without doubt been formed 

directly or indirectly by the weathering of feldspathic rocks. Those 

in the mountain regions, where the surface waters have had almost 

direct access to the material of the pegmatite dikes, have been formed 

directly by weathering. The kaolins around Bessemer City, Bostick's 

Mills, and Statesville may have been formed somewhat differently. 

There the areas underlain by the clay are wide rather than long and 

narrow, as in the mountain district, and possibly the feldspathic 

rocks from which the kaolin has been derived were formerly covered 

by swampy tracts, so that the surface water percolating through them 

to the bedrock became charged with carbonic and organic acids, which 

not only accelerated the process of weathering but may have caused 

the removal of some of the iron that was in the parent rock.

The data given below are based chiefly on studies of the deposits of 

the mountain region, which have been more extensively opened up, 

although the changes described might apply to the Piedmont area 

as well.

In the breaking down of the feldspar considerable silica is set free 

and must be removed in solution, for orthoclase on weathering gives

only 52 per cent of its weight, or 61 per cent of its volume of kaolinite.

The residual clay, however, is generally very compact and contains 

as much as 90 per cent of kaolinite. This high content of kaolinite 

may be due either to the settling of the material or to enrichment of 

the kaolin by the migration into it of kaolinitic material from the 

higher-lying parts of the deposit.

Few deposits contain an average of more than 40 per cent of kaolin, 

even where all the feldspar has been entirely decomposed, and the 

rest of the material is made up of other minerals, chiefly' quartz. 

Products of the decomposition of other constituents of the pegmatite 

may affect unfavorably the color or purity of the kaolin.

Even quartz, which is one of the most resistant constituents of 

the pegmatite, may sometimes show the effects of attack by the percolating waters, as in -the rounding of the edges of the grains, or the 

pitting of their surface by solution. Indeed, it is probable that they 

have invariably undergone solution to some extent, though perhaps
KAOLINS (WHITE RESIDUAL CLAYS). 21

only exceptionally is the solution marked. The quartz then has a 

pebbly appearance, and the crude kaolin may look very much like 

a mass of water-worn pebbles in a fine-grained sediment. The solution may be due to the action of the alkaline carbonates produced 

during the weathering of the feldspar, for it i^ well known that 

quartz is appreciably dissolved by alkalies. If the quartz in the 

original rock was in fine grains some of it may be completely dissolved, but much of it may nevertheless remain as grit or sand in 

the kaolin.

Beryl alters to mica or kaolinite and in altering to mica is apt 

to yield fine scales, which are difficult to separate from the flakes 

of kaolinite, and may injure the refined product if the beryl was 

originally present in any quantity.

Tourmaline, though probably strongly resistant to weathering,

appears in some deposits to have been decomposed to a mixture of 

clay and iron oxide.

Muscovite loses its elasticity and luster and alters to a hydrated 

mica, but generally it changes so slowly that it may be picked by 

hand from the kaolin, provided the plates are large enough, and 

much of it may be so slightly altered that it can be sold as sheet, 

ground, or punch mica, depending on its size.

Biotite, hornblende, and any other ferriferous minerals may be 

altered to a number of compounds, among which may be limonite or 

other iron hydroxides, and even ferrous carbonate. In the presence 

of abundant oxygen the hydroxides are apt to form; and these 

stain the kaolin brown or yellow. In the absence of oxygen ferrous 

carbonates are produced, and as these are soluble in carbonated water 

they may be carried away in solution. Thus, near the surface, 

where the percolating waters carry abundant oxygen, staining by 

iron salts is rather common, whereas with increase of depth the 

stains decrease, except where crevices furnish channels along which 

the water may flow freely, and at ground water level the kaolin is 

practically free from them.

The most objectionable components of the kaolin are the products 

of the decomposition of garnet. When the crystals are decomposed 

they give rise to chlorite and other micaceous products that are 

commonly colored reddish brown by iron hydroxides or other iron 

compounds. The heaviest particles may be separated from the 

kaolin by washing, but some of the lightest material floats over with 

the slip and is distributed through the refined kaolin, even seriously 

impairing its value. In the clay bank the decomposed crystals of 

garnet appear as little circular brown spots. If the spots are few 

the clay containing them may be removed by hand sorting before 

the crude material is sent to the washer, but if abundant there is 

no recourse but to abandon that part of the mine in which they occur.
22 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES. 

VARIATION IN COMPLETENESS OJT KAOLINIZATION.

Most pegmatite dikes contain a large proportion of quartz, so 

that the average quantity of kaolinite in their decomposed parts is 

generally much less than 40 per cent, so low that the deposits are 

not profitably workable throughout. However, richer pockets are 

scattered through the dike mass, and upon these the miner depends 

for his commercial success. He therefore passes by the poorer material and removes the richer.

As kaolinization progresses downward from the exposed surface 

the completeness of the process becomes less and less as depth 

from the surface increases until the proportion of undecomposed 

material becomes so great that deeper mining is impracticable. 

Although even at great depth, the feldspar is partly kaolinized, the 

quantity of undecomposed feldspar is so great that a crowbar can 

not be forced into a mass of it without hammering. The quantity 

of kaolin in the mass is there so small that the increased cost of preparing it for market makes its mining unprofitable.

The depth at which mining becomes unprofitable differs in different dikes, but in deposits well up on slopes it is generally at about 

95 feet from the exposed surface. The purer kaolin lies near 

water level, and above this plane kaolinization is practically complete. When the miners reach water level the kaolin becomes so 

plastic that it-is difficult to maintain the shafts, and for this and 

other reasons the mining operations become so expensive that the 

shaft has to be abandoned unless it can be drained. Consequently 

deposits high up on slopes are generally minable at greater depths 

than those at the bases of slopes or on plains, where the Avater level 

is nearer the surface. Usually the best kaolin in any deposit lies

near the level of the ground water. Below this level the completeness of kaolinization rapidly diminishes with depth, and in many 

deposits the dike material a few feet below the water level has been 

protected from alteration to such an extent that it might be used 

as a source of feldspar. In general, a dike is richer in kaolin near 

its footwall than near its hanging wall. The hanging wall, especially if it is composed of schists, protects the material to some 

extent against downward-flowing water, but near the footwall the 

water accumulates.

Though the statements just made are correct as to the completeness of kaolinization of the feldspar in the different parts of a dike, 

yet the present relation of a pegmatite to the surface features of the 

vicinity is not the only condition that determines the thoroughness 

of its alteration. Fresh feldspar and completely kaolinized feldspar 

occur at the same elevation and near each other in neighboring dikes. 

Watts 11 calls attention to the fact that a few years ago, at Penland,

31 Watts, A. S., Mining and treatment of feldspar and kaolin: Bur. Mines Bull. 53, 

p. 17, 1913.
KAOLINS (WHITE RESIDUAL CLAYS). 23

N. C., a dike in an advanced stage of kaolinization was being worked 

for kaolin, and that another dike 50 yards distant which was also 

being worked contained fresh feldspar. He adds, however: "The 

kaolin deposit is not well defined and appears to have been disturbed 

by a slide; whereas the fresh feldspar is in a well-defined dike."

It is not apparent to the writer why the kaolin at P'enland is 

regarded as a slide. A sketch map of the occurrence is given in 

figure 4 (p. 49). However, in one of the shafts from which kaolin 

was taken a distinct dike of pegmatite about 2 feet wide cut diagonally through the kaolin, and the material of this dike is practically 

unchanged. The feldspar of the small dike is microcline and not 

orthoclase. Evidently the microcline resisted decomposition more 

successfully than the orthoclase and is therefore nearly intact. Some 

of the contrasts in the degree of alteration of neighboring dikes are 

probably due to differences in the character of the feldspar.

REFINING AND BY-PRODUCTS.

A thorough system of washing should remove many of the objectionable constituents from the crude kaolin and yield a refined product of nearly constant composition. Constancy of composition is 

more easily attained than freedom from impurities. At one mine 

the product was maintained at a constant standard during at least 

five years, as indicated by the table below, which shows the limits of 

variation in the refined kaolin shipped between the years 1890 and 

1895. The analyses were made by N. P. Pratt on material dried at 

100° C.

Analyses of washed kaolins from Dillsboro, N. C. 

\

[Furnished by Harris Clay Co.]

-

Silica (Si02 ). ........................................................................

Lime (CaO). ........................................................................

Alkalies (K2 0+Na2O) . ..............................................................

Water (H2O). .......................................................................

1

46.47

33. 82

.89

.28

.25

.75

13.34

2

40.47

38.14

.36

.50

.09

.64

13.61

1. Analysis of kaolin high in iron and alkalies.

2. Analysis of kaolin low in iron and alkalies. .

Some of the objectionable constituents are not so readily removed. 

Nearly all refined kaolin contains some quartz and feldspar, and 

some of it contains a large proportion of more objectionable components. Washing alone, no matter how carefully and thoroughly 

done, will probably not remove all the iron hydroxides, for some 

of them are colloidal, but unquestionably many of the heavy ironstained particles and much of the quartz that now finds its way into 

the refined product can be removed by more careful washing.
24 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Analyses of the crude and washed kaolins from the Springer pit, neai 

Webster,12 give some idea of the improvement made by washing an 

unusually good crude clay.

Analyses of crude and washed kaolin from the Springer pit near Webster, N. C.

Silica (SiO2) ........................................................................

Alumina ( AhOs). - ..................................................................

Ferric oxide (FejOs) ................................................................

Ferrous oxide (FeO) . ...............................................................

Lime (CaO). ............................................ . .........................

Magnesia (MgO) . ...................................................................

Alkalies (Na^O + KsO) .................................. . .........................

Water (H2 0 above 100° C.) ........ . : ...............................................

Moisture (H2 0 below 100° C.) .......................................................

1

62.40 

26.51 

1.14

.57 

.01 

.98 

8.80 

.25

100. 66

2

45.78 

36.46 

.28 

1.08 

.50 

.04 

.25 

13.40 

2.05

99.84

1. Crude material.

2. Washed material.

The crude material contained 15.61 per cent of quartz and 18.91 

per cent of feldspar and the washed material contained 6.60 per 

cent of these two components.

In some of the deposits a great deal of the quartz occurs in grains 

so fine that it passes the sand wheels used to remove the coarse components from the crude kaolin. This quartz may pass into the mica 

troughs and settle, and if not mixed with much mica it may be 

used in scouring soaps and other cleansers. It is not sharp enough 

for "sandpaper and rarely pure enough for use in making glass. 

Occasionally the coarser quartz, when fairly uniform in size, has 

been used in roofing but with what success is not known.

Much of the mica that was in the original pegmatites has remained 

unaltered during the kaolinization of the feldspar and is now embedded in the crude clay. That which is in large flakes or aggregates of flakes may generally be easily separated from the kaolin 

by hand, and if it is clean and uniform in structure may be put on 

the market as " sheet mica " or if in smaller flakes as " punch mica." 

Indeed, some of the mines are now producing mica of this kind. As 

the mica must be removed from the mine and separated from the 

kaolin, the small additional expense required to save and sort it is 

warranted by the price at which it can be sold. In some pegmatites, 

however, the mica occurs in very fine scales. Moreover, the coarser 

mica found in most dikes is so severely pounded and torn in the 

processes of refining the crude clay that much of it is shredded into 

fine particles. The quantity of fine mica that passes the sand wheels 

may be very great. Much of it drops to the bottom in the mica 

troughs, but the fine scales float out in the slip that goes to the settling tanks. By placing screens of the proper mesh in the sluice

12 Rles, H., Clay deposits and clay industry In North Carolina : North Carolina Geol. 

Survey Bull. 13, p. 62, 1897.
KAOLINS (WHITE RESIDUAL CLAYS). 25

carrying the slip most of this mica might be saved and sold as 

"ground mica." At the 'Sprucepine mine an excelled grade of 

ground mica is now being saved at very little cost.

COMPOSITION.

A number of analyses of both crude and washed kaolins from 

North Carolina have been published. The crude kaolin usually has 

a high content of silica, whereas the washed kaolin commonly shows 

a ratio of silica to alumina, which closely approaches that of kaolin - 

ite, although occasionally the content of silica falls below that of 

kaolinite, thus indicating that hydrous aluminum oxide or some 

hydrous aluminum silicate other than kaolinite may be present. A 

few illustrative analyses are given below.

Analyses of kaolins from North Carolina.

Silica (Si02 ). ..............................

Ferric oxide (FejOa) ......................

Potash (KjO).. ...........................

Soda (NajO)... ...........................

Water (HO2 above 100° C.j. ..............

Moisture (H2 0 below 100° C. ).,...........

Silica (Si02). ..............................

Alumina (AljOs) ..........................

Lime (CaO). . .............................

Magnesia (MgO) ..........................

Potash (K2 0). ............................

Soda (NasO).. ............................

Titanic oxide (TiOs) ......................

Water (HaO above 100° C.) ...............

1

62.40

26.51

 1.14

.57

.01

> OO

8.80

.25

100. 88

7

45.56

38.65

.41

.05

.08

.80

.55

.10

13.90

100. 10

2

45.78

36.46

.28

1.08

.50

.04

. £O

13.40

2.05

99.84

8

45 61

38.63

.46

.08

.08

.90

.66

13.57

99.99

3

46.95

37.73

.15

Trace.

/ .60

| .18

.05

13.99

99.65

9

46.51

39.91

.11

.00

.00

.00

13.38

100.01

4

45.70

40.61

1.39

.09

.45

> A. o*

8.98

.35

100. 39

10

49.56

37.53

.02

.00

.06

.05

.05

12.65

99.96

5

46.41

38.46

.07

.07

f .42

\ -17

14.40

100.00

11

46.95

37.24

.40

Trace.

Trace.

.49

.21

.05

14. 10

99. 47

6

46.30

39.06

.20

Trace.

Trace.

.60

.11

.04

13.77

100. 08

12

44.00

40.79

.11

Trace.

Trace.

.55

.07

Trace.

14.72

100.21

1. Crude kaolin from Springer pit, Webster. North Carolina Geol. Survey Bull. 13, 

p. 62, 1897.

2. Commercially washed sample of kaolin from Springer pit, Webster. North Carolina 

Geol. Survey Bull. 13, p. 62, 1897.

3. Sample of kaolin from Hog Rock mine, Webster. Washed in laboratory. Bur. Mines 

Bull. 53, p. 131, 1913.

4. Washed kaolin from Hog Rock mine, Webster. Idem, p. 61.

5. Commercially washed sample of kaolin from Roda mine, Sylva. Analysis furnished by Harris Kaolin Co.

6. Sample of kaolin from Buchanan property, Sylva. Washed in laboratory. Bur. 

Mines Bull. 53, p. 154, 1913. (Probably same as Ross property. See p. 55.)

7. Commercially washed sample of kaolin from Old Sprucepine mine, Sprucepine. 

Analysis furnished by Harris Kaolin Co.

8. Commercially washed sample of kaolin from Harris mine, Penland. Analysis furnished by Harris Kaolin Co.

9. Commercially washed sample of kaolin from Wilson mine, Micaville. Analysis furnished by Harris Kaolin Co. Calculated to 100 per cent dry material.

10. Commercially washed sample of kaolin from Hand mine, Woodrow. Analysis furnished by Harris Kaolin Co. Calculated to 100 per cent dry material.

11. Sample of kaolin from mine of Harris Clay Co. near Bryson. Washed in laboratory. Bur. Mines Bull. 53, p. 126, 1913.

12. Sample of kaolin from mine of Gurney Clay Co. near Franklin. Washed in laboratory. Idem, p. 135.
26 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

KAOLINS IN THE MOUNTAIN REGION.

T )

OCCURRENCE.

The kaolins of the mountain districts are all, so far as known, 

residual products resulting from the decay of pegmatite dikes that 

cut the schistose rocks and granites. These dikes are not continuous 

for long distances and consequently form very narrow lenses. Many 

of them are parallel to the plains of schistosity of the rocks with 

which they are associated, and the strike of these rocks in turn is 

parallel to the trend of the mountain ridges in their vicinity. As 

most of the ridges have a general northeasterly trend most of the 

dikes also have a northeasterly trend. A few of the dikes cut across 

the planes of schistosity, but most of these crosscutting dikes are 

offshoots of main dikes that follow those planes. As a rule the 

largest deposits of kaolin have been produced by the decomposition of the larger dikes and therefore have a northeast trend. The 

crosscutting dikes are smaller than those that run parallel to the 

structure of the schists and have given rise to smaller deposits of 

kaolin.

CHARACTER OF THE PEGMATITES.

The relations of the pegmatites to the neighboring rocks have been 

so well described by Sterrett 13 that his statements concerning them 

may be quoted almost without modification. After stating that the 

pegmatites of North Carolina occur mainly in the Roan gneiss, which 

is a series of hornblendic gneisses and schists, and in the Carolina 

gneiss, which is nonhornblendic, he says:

Pegmatites occur in irregular masses, streaks, lenses, augen, or balls, some 

of them having no visible connection with other pegmatite bodies. They 

range from a fraction of an inch up to many yards in thickness. * * *

Horses, or inclusions of wall rock, are common in pegmatite. Some of them 

are in the form of bands or sheets parallel to the walls, and the schistosity of 

these bands is also parallel to the walls. They range from an inch of two up 

to several feet in thkkness, and their length may be many times their width. 

Elsewhere they occur as irregularly shaped masses, from a few inches up to 

several feet thick. * * * In some places the horses are partly pegmatized 

by streaks of pegmatite ramifying through them and by the development of 

considerable feldspar and quartz through their mass. In such places no sharp 

line can be drawn between the pegmatite and the original horse.

Pegmatite is closely allied to granite in composition. As in granite, the 

essential constituents are feldspar and quartz, with more or less mica and 

other accessory minerals. Though hornblende is rather a common mineral in 

granite, it is less so in pegmatite. Orthoclase and microcline are the most 

common varieties of feldspar found in pegmatite. In many places, however, 

a variety of plagioclase, either albite or oligoclase, makes up part or all of the 

feldspar component. The feldspar occurs in masses and rough crystals, some 

of them with a diameter of several feet.

13 Sterrett, D. B., Mica deposits of North Carolina : North Carolina Geol. and Econ. 

Survey Economic Paper 23, p. 37, 1911, and U. S. Geol. Survey Bull. 430, pp. 601-604, 

1910.
KAOLINS (WHITE RESIDUAL CLAYS). 27

Quartz assumes various forms and positions in the pegmatite. In many places 

it bears much the same relation to the feldspar and mica as in granite, the 

three minerals being thoroughly mixed with one another; but the individual 

grains are many times larger than in ordinary granite. Not uncommonly the 

quartz and feldspar assume a graphic-granite texture in a portion of the 

pegmatite. Another common feature is the occurrence of large separate masses 

of quartz occupying various positions in the pegmatite. Such quartz masses 

may be irregular in form and but little influenced by the shape of the pegmatite or inclosing wall. Many of them, however, lie in bands or sheets parallel 

to the walls. There may be one or more of these quartz bands constituting 

varying proportions of the pegmatite. Their thickness ranges from a fraction 

of an inch up to 6 or more. feet. Many of them are lenticular in shape, the 

length varying from four or five to twenty or more times the thickness. In 

numerous* places these quartz streaks or veins are persistent through the whole 

length of the pegmatite exposed. Some inclose feldspar or mica bodies; others 

do not. The quartz of these segregations is massive and generally granular, 

though locally crystallized. If crystallized it may be translucent or clear and 

of a dark, smoky, or light color. It is generally rather pure and does not

contain feldspar or mica in appreciable quantity.

Muscovite is the common mica of pegmatite. * * * Biotite occurs in 

moderate quantity in a few deposits and in smaller amount in many others. 

* i* * The mica occupies various positions in the pegmatite. Where the 

rock has a typical granitic texture the mica may be found evenly distributed 

through it. More commonly the larger crystals will be found either in clusters 

at intervals through the " vein" in places connected by streaks of small 

crystals, or collected along one or both walls of the pegmatite, with some of the 

crystals partly embedded in the wall rock. Where there is a quartz streak 

within the pegmatite the mica occurs on either or both sides of it. The mica 

may be partly embedded in the quartz or be scattered through the remaining 

portion of the pegmatite, which generally is composed largely of feldspar.

The dike rocks in places contain garnet, beryl, tourmaline, and 

other rarer compounds. During kaolinization these minerals may be 

changed partly to kaolin and partly to a mixture of iron and manganese oxides and hydroxides,.which are likely to stain the kaolin in 

streaks and to produce in it little nodules of limonite. The biotite 

breaks down into limonite and perhaps chlorite or some other hydrated micaceous mineral and produces soft black masses in the midst 

of the clay. These constituents are particularly objectionable because 

of the difficulty of separating them from the kaolin, for their fine 

scales are apt to float and be carried into the settling vats when the 

kaolin is collected.

Beryl and tourmaline occur chiefly in the feldspathic portions of 

the dikes. As the beryl readily alters to kaolin it is not found in the 

kaolinized product, but the tourmaline changes to limonitic masses 

which color the clay brownish black.

KAOLIN MINES.

All the deposits of kaolin now being worked in North Carolina 

occur in the mountain district, and all of theni are residual deposits
28 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

from pegmatites. In addition there are many other similar deposits 

which are not being worked. Some of them are too small for profitable exploitation; others, though large, are not near the railroads; 

others are owned by people who lack financial means to develop them; 

and others are being held in reserve by the owners of the present active plants. Other deposits include some that are promising but nave 

not been brought to the attention of the public and many which have 

never been explored.

In this paper only active deposits, those that have recently been 

active, promising deposits near transportation lines, and deposits held 

in reserve are described. On the accompanying map (PL I) the locations of these deposits are indicated and also the locations of known 

deposits which are not described in the text, but which will be referred to in a forthcoming report of the North Carolina Geological 

and Economic Survey.

The eight active mines of the State are in Haywood, Jackson, 

Mitchell, and Yancey counties. Three others, now inactive but partly 

equipped for operation, have been opened in Swain, Haywood, and 

Mitchell counties, and a score or more promising deposits might possibly be developed into producing properties under favorable conditions. The deposits are described in general from southwest to northeast.

DILLSBORO, JACKSON COUNTY.

Hog Rock mine. The Hog Rock mine of the Harris Kaolin Co. 

is about 4 miles southeast of Dillsboro, near Harris, on Little 

Savannah Creek, Jackson County. It is the oldest mine in the State 

and has been operated continuously for 30 years.

The deposit is well up on the slope of a hill which has been reduced by open-cut work to three terraces above the .valley level. 

The present workings are on the tAvo higher terraces. The deposit 

consists of pockets of rich kaolin separated by narrow lenses and 

streaks of quartz and by layers of gneiss. In the aggregate, so far 

as it has been developed, it is 900 feet long and 250 feet wide at its 

broadest part, but its width diminishes at one place to 100 feet and 

again increases to 200 feet. It is cut diagonally by a spur of quartzmica rock 400 feet long and 30 feet wide. West of this rock there 

are other deposits 15 to 20 feet wide, which are separated from the 

larger deposit by several hundred feet of gneiss. Still farther west 

a new deposit about 300 feet longhand 100 feet wide has recently 

been opened. It is separated from the deposits-to the east by 750 

to 900 feet of gneiss and is apparently entirely independent of them.

The depth to which kaolinization has progressed differs markedly 

in different parts of the mine. The maximum depth to which mining has gone is 125 feet from the original surface. This depth has
KAOLINS (WHITE RESIDUAL CLAYS). 29

been reached partly by open cuts and partly by shaft. Because of 

the pockety character of the deposit a reliable estimate of the reserve can not be made.

The walls of the deposit are not well exposed. They appear to be 

formed of decomposed Carolina gneiss. The quartz-mica rock that 

penetrates the large deposit is mainly quartz streaked with little 

tongues of pegmatites. It contains pockets of decomposed feldspar, 

clumps of mica, small masses of limonitic material that may have 

come from hornblende or tourmaline and nodules of soft brown and 

black flaky limonite, as well as others of manganese oxides.

The deposits at this place evidently represent a large dike and several smaller parallel dikes, which in general have a northeastwaid 

trend and a nearly vertical dip. The dikes were irregular in width, 

and the feldspar and quartz, in the main dike at least, were irregularly distributed. ' 

The crude clay is distinctly cream-colored when first mined, but it 

becomes darker after it has been dried out and exposed to the air. 

This darkening is apparently due to the oxidation of some iron compound. The kaolin contains a great deal of fine white mica and 

fine sand, a little decomposed feldspar, a few reddish-yellow stains, 

and a few concretionary nodules of mixtures of limonite and psilomelane or wad. Most of these nodules are small, but some of them art> 

about an inch in diameter. They are readily separable from the 

kaolin in the refining process, and consequently manganese is rarely 

reported in analyses of the commercial product. The material from 

different pockets differs in chemical composition, but a uniform product is maintained by careful mixing.

The crude kaolin passes through agitators, sand wheels, the usual 

tanks, and screens, and after being pressed and dried it is hauled by 

horse tram 4 miles on a narrow-gage road to a siding at Dillsboro, on 

the Murphy branch of the Southern Railway.

The output of the mine and plant is about 2,400 tons annually. 

Its capacity is about double this quantity, provided sufficient labor is 

obtainable.

The kaolin from the Hog Rock mine is well known to nearly all 

the white-ware potters of the Middle West. It has been used by 

them in the manufacture of china and porcelain. It has also been 

employed in making floor and wall tile and is now being tested for 

use in glass-melting pots. For some years it has constituted a part 

of the mix for making the binder for vitrified carborundum wheels.

The following tests of the crude kaolin were made in the laboratory of the Bureau of Mines at Columbus, Ohio:
30 HIGH-GEADE CLAYS OF THE EASTEBN UNITED STATES.

General physical tests of kaolin from Hog Rock mine, Dillsboro, N. C.

Workability ________ Short, sandy; corners tear; dries well. 

Color of un fired clay _____________________ White. 

Water of plasticity, in terms of dry clay_ _____ per cent 44. 78 

Air shrinkage by volume, in terms of dry clay ___ do _ 20.92 

Air shrinkage, linear ___ _ ___ __1 __ do 7. 6 

Moisture factor on dry basis _______________ do __ 1. 10 

Fineness test:

Residue, 20-mesh sieve _______________ do_ 38. 60 

Residue, 65-mesh sieve ________________ do __ 7.08 

Residue, 100-mesh sieve _______________ do . 65 

Residue, 200-mesh sieve _______ »_ _____ do 5.80 

Amount passing 200-mesh sieve _ ______ do - 47.87

Eire tests of kaoUn from Hog Rock mine, Dttlsboro, N. C.

Temperature 

(°C.).

1,190 

1,250 

1,310

Porosity 

(per cent in 

terms of burned 

volume).

37.1 

41.9 

36.8

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

16.0 

18.6 

17.9

Temperature 

(°C.).

1,370 

1,410

Porosity 

(per cent in 

terms of burned 

volume).

30.9 

24.9

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

24.1 

30.7

Roda mine. The Roda mine, which is operated by the Harris 

Kaolin Co., is in Jackson County, about 1\ miles southeast of Dillsboro and 5 miles southeast of Webster on the south side of Tuckasegee 

River, opposite the mouth of Cany Fork. The plant in which the 

clay is filtered and pressed is on the south side of the river, 1 mile 

east of Webster. The washer is near the mine.

In his report on this mine Watts 14 says that the dike which gave 

rise to the kaolin

cuts diagonally a low ridge and has a northeasterly strike. A broad band of 

sugar quartz follows the south wall which is very crooked. The extent of the 

dike has been proved more or less by test pits, but the chief exposure is by a 

long tunnel driven from the west slope of the hill. This tunnel passes through 

a broad band of low-grade pegmatite material into a band having a low quartz 

content.

An average sample from a shaft sunk "into this band contained 

26 per cent of kaolin. ' Since Mr. Watts's visit the mine has been 

sufficiently developed to show two dikes, one 20 feet and the other 

40 feet in width, separated by 40 feet of rock. The deposit is pockety, 

and the clay in the different pockets differs somewhat in character.

In 1918 there were five active shafts, the material from which was 

mingled in the flume leading to the washer, so that the washed kaolin 

formed an average product of the whole mine. The crude kaolin 

yields about 25 per cent of refined product. The depth of the workWatts, A. S., Bur. Mines Bull. 53, p. 156, 1913.
KAOLINS (WHITE RESIDUAL CLAYS). 31

able clay is about 50 feet on the lower slopes of the ridge and more 

than 100 feet on its upper slopes. The estimated reserve is about 

10,000 tons in that portion of the deposit that has been developed, 

but it is plain that its entire extent has not yet been explored.

The crude kaolin.is Avhite and someAvhat sandy. It contains some 

fine mica, some sand, a few tiny black specks, large fragments of 

quartz and partly decomposed feldspar, and a few large flakes of 

silvery muscovite. Black streaks of a decomposed mineral are 

abundant near the Avail of the western vein, and near the surface 

streaks of red clay and bunches and streaks of soft black compounds of manganese spoil the kaolin, but the main mass of the 

clay is free from stain and dark streaks. Veins of mica, however, 

embedded in red clay, occur throughout the mass. Much of the 

mica is stained and. therefore useless, but 7 or 8 tons of rough material are separated monthly and put on the market as cut and 

scrap mica. It is noticeable that the better mica and the better 

clay are found together, and that where the mica is poor the kaolin 

also is apt to be inferior.

Under the microscope the kaolinite is seen to occur mainly in plates 

and flakes, but many of them are radially arranged, forming bundles 

and globular masses. The dark specks are composed of iron-stained 

clumps of kaolinite, pieces of stained feldspar, and here and there 

plates of ch.lorit.ic material and shreds of greenish-yellow mica that 

are fragments of decomposed muscovite. *

An analysis of the washed kaolin, furnished in 1917, is given 

iri the table on page 25.

The crude clay is carried to the Avasher by a flume. The slip is 

pumped to a pipe Avhich carries it to a flume, through which it 

floAvs by gravity to a tank on the top of a hill, then by a gravity 

siphon to the top of another hill 1£ miles distant, and finally by 

another flume 3 miles to the settling tanks at the plant on the river. 

After being pressed it is carried by motor truck 3 miles to a siding 

of the Southern Railway at Sylva. The normal capacity of the 

plant is about 2,500 tons of refined clay annually.

The uses of the kaolin from the Roda mine are the same as those 

of the kaolin from the Hog Rock mine. Indeed the kaolin of either 

mine is often substituted for that of the other.

V

WOODBOW, HAYWOOD COUNTY.

Mine of the Hand Clay Co. (Inc.}. The Hand Clay Co.'s mine 

(PL I) is about 1 mile southeast of Woodrow on the Pigeon River 

division of the Tennessee & North Carolina Railroad, a short branch 

that makes a connection with the Murphy branch of the Southern 

Railway system. Woodrow is 6 miles south of West Canton (its
32 HIGH-GEADB CLAYS OF THE EASTERN UNITED STATES.

post office), and the plant is connected with the railroad at Woodrow 

by a narrow-gage tram that uses cars drawn by mules. This deposit 

may be the same as the Sonoma prospect mentioned by Keith 15 in 

1907.

The deposit is well up on a hill slope that affords a convenient 

grade for sluicing the crude material to the refining and compressing 

plant in the valley. It is worked by an open cut 40 feet deep and 

90 feet wide and by 2 shafts, of which one in August, 1918, was 72 

feet deep and still in workable clay. Thirty-nine borings, distributed 

over an area 450 feet long and 120 feet wide, indicate a workable 

deposit at least 450 feet long by 90 feet wide and covered by an 

overburden not more than 5 feet thick. The deposit strikes about 

N. 20° E. and dips nearly vertically. Two tunnels, 55 feet and 125 

feet long, which cut across the deposit, show a fairly uniform bed 

of clay, broken here xVand there by streaks of quartz. The thickness 

of the deposit is not known, for the augers penetrated to depths of 

only 30 feet, but most of the holes were stopped in hard clay. As 

the present workings show a thickness of at least 90 feet of workable material, it is safe to assume the average thickness over tne 

whole area to be 60 feet. On this assumption the quantity of crude 

clay available is, about 135,000 tons. If 20 per cent is saved as 

refined kaolin the reserve is about 27,000 tons. If the average depth 

of the workable clay is assumed to be 90 feet the calculated reserve 

rises' to 40,000 tons. In making this estimate no allowance has been 

made for the presence of a horse of flint that shows in the pit. This 

horse may disappear at a greater depth or it may expand; at present 

its underground extension is unknown, though recent shaft work 

indicates that it is " playing out."

The walls of the deposit are not clearly defined, because the rock

has been so much broken down by weathering that its original character is not now recognizable. Keith 16 maps the country rock as 

Carolina gneiss, which is in accord with the abundance of weathered 

micaceous material in the overburden. The clay deposit Avas evidently a pegmatite dike striking about N. 20° E. and dipping about 

85° SE. In general it was uniform in composition, but in one place at 

least it was crossed by a mass of quartz which now appears as a horse 

in the kaolin. (See PL II.)

The crude clay is white, finely granular, and free from coarse 

quartz. It contains an abundance of quartz and is discolored here 

and there by small brownish-yellow stains similar to those seen on the 

sides of cleavage cracks in semikaolinized feldspar. In addition the 

clay contains numerous very small flakes of white mica and small

15 Keith, Arthur, U. S. Geol. Survey Geol. Atlas, PIsgah folio (No. 147), p. 7, 1907.

16 Keith, Arthur, op. cit.
TJ. S. GEOLOGICAL SURVEY 

PANORAMIC VIEW OF HAND MINE, WOOD
U. S. GEOLOGICAL SURVEY

N:T ".; - ".- :.- ' '' .^ tes»:'-»--v.>:. .-viU . '"

l. WALL OF PIT OF GURNEY CLAY CO., NEAR

FRANKLIN, N. C. 

Showing inclusfons of country rock in the kaolin.

PIT N
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE I

MAP OF

WESTERN NORTH CAROLINA

Showing location of kaolin deposits described in text

35°:

Rj A K /t> OSU.il I

j \J ^»SHEBORO '^,

" / V ^vx-v aV»« 

/ WWrovK \\

sT-TSo8ij.ee 

beeutJ'"

EXPLANATION

ACTIVE MINES PROSPECTS AND EXPLORATIONS

37 Rhodarmer prospect

Valentine prospect 

39 Seth Freeman prospect

55 0!hs prospect

56 Wiseman prospect

57 Isinglass Hi!l mica mine

58 Green mica mine

59 Tom Baxter mica mine

60 South Hardin rnica mine

61 Jessie Bare property

62 J. A. Smith deposit

63 J. A. Smith deposit

64 Piedmont tin mine

19 Rochester mica mine

20 West prospect

21 Bryson prospect

22 Cole & Black exploration 40 Snider prospect

23 Cagle Gap mica mine 41 Billingham prospect

42 Smith prospect

43 Thomas prospect

44 Howell prospect

45 Ben tier mica mine

46 Fiukin Ridge prospect

47 American.Mica & Mining Co. 65 Ervin prospect

60 .Filers & Jones deposit

67 Cashion & Furchess deposit

68 Eames deposit

69 Unnamed prospect

70 Overton deposit

71 Steele exploration

72 Bennett prospect

4H")

-a r McKinney prospect

A Hog Rock mine

B Rod a mine

C Hand Clay Co.

D Wilson mine

E Wyatt mine

F Job Thomas mine

G Sprucepine mine

H Sparks mine

	ABANDONED MINES

a Hewitt mine

b Payne & Sullivan mine

c Harris mine

d Gurney mine

e Southern Clay Co. mine

f lotla mine

g American Land & Development

	Co.'s mine

h N. C. Mining & Manufacturing Co.

i Springer pit

j Harris mine

k Clay Products Co.'s mine

1 Penland mine

1 Smith prospect

2 Messer prospect

3 Hyde prospect

4 Lenoir prospect.

5 McGuire exploration

6 Chalk mica mine

7 Raby mica mine

8 Porter mica mine

9 Cunningham prospect

10 Moore mica mine

11 Lyle prospectlS Kasson mica mine 

18 Billings prospect

14 Ferguson property

15 Frank prospect

16 Myers prospect

17 Sloan prospect

18 Sanders prospect

83°

24 Hall mine

25 Rose mine

26 Love prospect

27 Cowan prospect

28 Ashe prospect

29 Forest Hill mica mine

30 Harris prospect

31 Long mica .mine

32 Wyehutta mica mine

33 Herren prospect

34 Retreat prospect

35 Kins!and mine

36 Sonoma prospect

50 Young prospect

51 Snow Creek deposit

52 Firescald property

53 Tolley mica mine

54 Wiseman prospect

82
KAOLINS (WHITE RESIDUAL CLAYS). 33

crystals and larger groups of crystals of the same mineral. The yellow stains are most common in the neighborhood of the mica plates 

and especially around the larger crystals and groups of crystals and 

in the cleavage cracks between their plates, where infiltration has 

carried iron compounds and deposited them. The mica itself within 

the kaolin appears to be almost wholly unchanged except comparatively near the surface, where it has become red and opaque and has 

lost its elasticity. Even AV hen bleached by treatment with strong 

hydrochloric acid it remains opaque, except on thin edges, Avhere it 

seems to be only slightly double refracting if not entirely isotropic. 

It has lost completely its homogeneity and has been changed to an 

aggregate of tiny transparent or translucent particles, which in the 

mass appear white and opaque, as if they Avere kaol.in.ite. They are, 

however, so lacking in definite characteristics that their nature has

not been determined. The microscope reveals the presence also of 

numerous particles of partly kaolinized feldspar, small plates of 

reddish-yellow decomposed muscovite, flakes of a broAvn pleochroic 

mica that may be biotite, little aggregates of brown-stained kaolinite, 

and a feAv highly refracting grains that may be zircon. Some of the 

biotite flakes contain slender black needles, like the needles of rutile 

commonly seen in the biotite of igneous rocks.

The washed clay as put upon the market consists mainly of kaolinite material in flakes and granules, considerable quartz in irregular 

grains, a small quantity of kaolinized feldspar, and a few frayed' 

flakes and many fibers of muscovite together with here and there a 

little plate of slightly pleochroic brpAvn mica." Most of the kaolinite 

particles measure about 0.01 to 0.03 millimeter in diameter, but they 

are commonly grouped together into clumps Avhose diameters are six 

or eight times as great as the diameters of the individual grains. 

HoAvever, these grains are interspersed among others of smaller size, 

whose diameter averages about 0.004 millimeter. The quartz, mica, 

and feldspar are usually in much larger grains, often measuring 0.06 

to 0.08 millimeter. A feAv of the clumps of kaolin and also some 

of the particles of feldspar are stained yellowish brown.

An analysis of the Avashed clay is given on page 25. It is impossible to compute the composition of the kaolin with any close degree 

of accuracy, because some one of the constituents must have been 

determined by difference, and therefore if there is an error in the 

analysis it is not discoverable, and furthermore the proportion of 

muscovite and feldspar in the sample is not knoAvn. On the assumption that all the alkalies are in the muscovite and that the determination of combined Avater is correct the composition .of the sample AVHS 

about 90.50 per cent of kaolinite, 7.50 per cent of quartz, 1.33 per cent 

of alumina, 0.64 per cent of muscovite, and 0.08 per cent of miscellaneous minerals.

77412 22 4
34 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

The plant, which is near the mine, is well equipped with washing 

and filter pressing apparatus. Its production during the past 

few years has been at the rate of 2,400 tons of refined kaolin annually, but if labor was abundant the output might perhaps be doubled. 

Changes made in the plant during the winter of 1918-19 may reduce 

its capacity to a slight extent, but the quality of the output will be 

improved. These changes consist in lengthening the mica troughs 

and in replacing the 100-mesh sieves by others of 130 mesh. It is 

hoped by these changes to reduce the quantity of quartz in the refined 

product.

The clay from this mine has been used in making china, porcelain, 

and other kinds of white ware. It is introduced into mixtures of 

imported and other domestic clays to the extent of 2| to 15 per cent. 

Letters from the Bureau of Standards to the company under dates 

of December 5, 1917, and March 6, 1918, declared it to be of good 

grade for pottery. When burned to cone 8 (1,290° C.) the material 

was still a very excellent white. The sample submitted was fine 

grained, as much as 94.61 per cent passing the 300-mesh sieve. When 

introduced in the proportion of 28 per cent into a porcelain mixture and fired in the biscuit to cone 8 and in the glost to cone 4 

(1,210° C.) a vitrified body of " a very satisfactory white resulted."

The following tests of the washed clay were made in the laboratory of the Bureau of Mines at Columbus, Ohio:

General physical tests of washed kaoltin from Woodrow, N. C.

Workability__________Not very plastic; makes good bars. 

Color of unflrecl clay_________________________White. 

Water of plasticity, in terms of dry clay_____per cent 47. 5 

Air shrinkage by volume, in terms of dry clay___do__ 28.91 

Air shrinkage, linear, calculated___________do__ 10.8 

Moisture factor on dry basis _ __ _ do 1. 56 

Fineness test:

Residue, 20-rnesh sieve-__ __ _____..__do_- 

Residue, 65-mesh sieve_______________do_- 

Residue, 100-mesh sieve_______________do_- 

Residue, 200-mesh sieve _ ________do___.

Amount passing 200-mesh sieve______________do_ 

Fire tests of washed kaolin from Woodrow, N. C.

.00

.07

.04

.60

99.34

Temperature 

(°C.).

1,190 

1, 250 

1,310

Porosity 

(per cent in 

terms of burned 

volume).

39.4 

39.4 

37.7

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

17.1 

19.3 

19.7

Temperature 

(°C.).

1,370 

1, 410

Porosity 

(per cent in 

terms of burned 

volume).

31.4 

27.2

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

27.3 

31.0
KAOLINS (WHITE RESIDUAL CLAYS). f 35 

MICAVILLE, YANCEY COUNTY.

Wilson mine. The Wilson mine of the Harris Kaolin Co. is 1 mile 

southeast of Micaville (fig. 10), and the washing plant is 1 mile to the 

northeast. There are two cuts on the same deposit, with one shaft 

in each cut.

Nothing of special geologic interest can bfc seen in the pits. The 

overburden is the common red clay, and its thickness ranges from 

3 to 8 feet. Except for the thin veneer of overburden around its 

top, the walls of the pit are almost entirely formed of kaolin. At one 

place rock shows for a few feet, but otherwise only white clay is 

visible. From the present development it appears probable that the 

deposit ranges in width between 18 and 75 feet and that the merchantable kaolin is 30 to 50 feet deep. Its strike is N. 60° E., and 

its dip is about 85° SE.

The kaolin is very light cream-colored. It contains fine flakes of 

white mica, sand, fragments of quartz, and a little biotite that prevents the separation of the fine white mica as a commercial product. 

On the other hand, many streaks and isolated clumps of coarse white 

mica are scattered through the mass, and from this material about 

one hundred dollars'worth of sheet and punch mica is saved monthly. 

An analysis of the washed kaolin, made in 1914, is given on page 25.

The crude clay is sent to the washing plant, whose capacity is about 

350 tons monthly, provided sufficient labor is available. From the 

washer it is sluiced 1£ miles to the settling plant at Lamonti, on the 

Black Mountain Railroad.

The Wilso'n clay has been used with success in the manufacture of 

china and semivitreous porcelain of all types. About 15 per cent 

goes into the mix, together with six or seven other clays, for making 

semivitreous ware and a little less in that used for making table 

china. The major portion of the mix, besides flint and spar, is made 

up of English china and English ball clays.

Wyatt mine. The Wyatt mine is a new opening about 1 mile 

northeast of Micaville. It is. across the stream from the Lamonti 

plant, where the output of the mine will be prepared for shipment.

In September, 1918, the mine consisted of several opening's on the 

side of a hill about. 600 feet south of the Lamonti plant and about 

100 feet above it. Toward the east end of the property two veins 

separated by 50 feet of rock are visible. About 600 feet southwest 

of the eastern opening, which is a shallow pit, the two veins unite 

and form a single vein 70 feet wide. In a tunnel a short distance 

south of the pit a mass of kaolin 35 feet in width is exposed. It 

contains streaks of mica and of red-stained material and is intersected by a nearly horizontal horse of red clay. At the end of the 

tunnel the kaolin fingers out in thin stringers, but 34 feet beyond
36 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

more kaolin occurs in a deposit Avhich is said to be 22 feet Avide. 

According to Mr. Hise, the superintendent of the property, these 

two veins unite 300 feet southwest of the tunnel into a single Avider 

vein. He says that the system of veins can be followed for 1,100 feet. 

The kaolin is covered^by 4 feet of overburden, and the average depth 

of the workable clay, as revealed by borings, is 42 feet. In some 

places the depth to hard rock is 60 feet.

Only about 10 carloads of clay had been washed by September, 

1918, but preparations were being made for systematic operation. 

The washer is on the hill near the mine. The slip is sluiced down to 

the plant at Lamonti, where it is mixed with that from the AVilson 

mine. The mixed kaolin is to be the standard commercial product 

in the future.

TOECANE, YANCEY COUNTY.

Job Thomas mine. The Job Thomas mine (fig. 10, p. 62) has 

been worked since 1914 by the Interment China Clay Co., of Erwin, 

Tenn., and Bandana, N. C. The mine is 3^ miles southwest of Toecane, on the north side of Chestnut Mountain. The deposits are 

pockety and therefore difficult to work, so that it is proposed to 

abandon the mine as soon as a neAv source of clay is developed.

The crude clay is like that of the Wilson mine. It is light creamcolored and contains sand, fine mica, and red streaks like the other 

crude kaolins of this district. The overburden consists of 3 to 8 

feet of red clay.

The washer is near the mine. After passing through the usual 

troughs and screens the slip fknvs by gravity in a flume 2-| miles to 

the filter plant at Interment, on the Carolina, Clinchfield & Ohio 

Kailway, 2 miles south of Toecane. The capacity of the plant is 

400 tons of refined kaolin monthly.

The kaolin from the Job Thomas mine has been used in the manufacture of china. Occasionally it is mixed with other domestic 

kaolins, but generally with Florida and English china clay and 

English and domestic ball clays, especially in the mix used for making porcelain.

Pit of the Clay Products Co. At one time the Clay Products Co. 

(fig. 10, p."62) operated a pit about 100 yards from the Job Thomas 

mine. It Avas probably on a parallel dike. The deposit Avas small 

and pockety. A tunnel that traversed it exposed good kaolin, which 

was intersected, hoAvever, by many streaks of schist. The place was 

never sufficiently developed to prove its value. It was Avorked a year, 

and after producing about 40 tons of refined kaolin that had been 

washed by hand it was abandoned.

SPRUCEPINE, MITCHELL COUNTY.

JSprucepine mine. The present openings of the Sprucepine mine 

of the Harris Kaolin Co. (fig. 10) are on the slope of a hill about
KAOLINS (WHITE EESIDUAL CLAYS). 37

three-fourths of a mile southeast of Sprucepine station on the Carolina, Clinchfield & Ohio Railway, near the mouth of Beaver Creek. 

The settling tanks and pressing plant are on the railroad near the 

station.

The deposits now being operated were first opened in 1916. Before that time the product was obtained from a deposit 2f miles 

north of Sprucepine near the head of Beaver Creek and then was 

sluiced to the plant on the railroad.

The present mine consists of two openings about 500 feet apart. 

The western opening has been worked for two years and the eastern 

one since March, 1918. The western opening has been Avorked by 

open cut to a depth of 30 feet and by shafts to a further depth of 

55 feet. At this depth dynamite is used to loosen the material and 

beyond this depth mining is unprofitable. The kaolin from this 

opening is light cream-colored. The overburden, composed of red

clay and broken rock, is from 6 feet to 10 feet thi<jk. The crude 

kaolin contains the usual impurities quartz, mica, black lumps of 

manganese oxides, and here and there small masses of stained clay. 

The dike in which it occurs probably strikes about north, but its 

walls are not clearly enough revealed to warrant a definite opinion.

In the eastern pit two shafts were down 30 feet in August, 1918. 

Both contained so much water that pumping was necessary to- keep 

them in condition to be worked. The kaolin obtained from this 

pit is white, not cream-colored, like that from the western pit, but it 

contains the same impurities, though in somewhat different forms. 

The quartz occurs in grains and also in little round pebble-like 

fragments. The appearance of their surfaces suggests that they 

have been corroded. The mica occurs in very fine flakes. In washing the kaolin the mica is separated from the slip by 100-mesh sieves. 

This mica after separation consists of plates of fresh muscovite between 0.2 and 0.5 millimeter in diameter, many smaller plates and 

shreds of the same mineral, a few flakes of a reddish-yellow mica 

that is probably an altered muscovite, and here and there a plate 

of: a slightly pleochroic dark-yellowish red mica that may be a 

partly decomposed biotite. In addition, there is much kaolinite in 

very small flakes and shreds and a few clumps of dark material 

that may be stained kaolinite. About 90 per cent of the mass is 

fresh muscovite. About a thousand pounds is saved daily and sold 

as ground mica to rubber and roofing manufacturers. The other 

impurities are nodules of soft black material, probably manganese 

oxides, and streaks of yellow clay.

The deposit at this place is probably large. It has not yet been 

sufficiently developed to uncover distinct walls nor is the depth of 

kaolinization knoAvn. The kaolin, however, is cut by horses of red 

clay, some of which are 15 feet wide. These probably "represent 

decomposed country rock, which may pass into well-defined rock.
38 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

at greater depths than have thus far been reached. Borings around 

the open pit in which the shafts are sunk show nothing but kaolin 

and streaks of yellow or red clay.

The crude clay is cleaned in washers near the pits and the resulting slips are sluiced in a common trough to the settling, drying, and 

filtering plant on the railroad. They are thoroughly intermingled 

before they reach the settling tanks, and in this way a uniform 

product is assured.

The present capacity of the mine and plant is about 5,500 tons 

annually, if labor is abundant, but this output is not always attained. 

With the completion of a hydroelectric plant on Toe River it may 

be possible to install labor-saving appliances, and the output may be 

increased.

The users of the Sprucepine kaolin include most of the potters 

who use also the kaolin from the Hog Rock and Roda mines near 

Webster. In the manufacture of china and white ware a mixture 

is made with imported clays and clays from Florida or Tennessee 

or with clays from both these States. The Sprucepine kaolin is a 

favorite among most of the potters who use it. Some of them employ it to the extent of 15 per cent of the total mix and contemplate 

increasing the quantity used in order to decrease the amount of imported clay now employed, whereas others report that they are 

gradually substituting for it some of the domestic clays from other 

sources. One potter declares that he uses no imported clay but 

makes his mix entirely of domestic materials. The Sprucepine kaolin 

is also used in the mixture of domestic clays employed in making 

spark plugs and other types of porcelain. Some of the largest manufacturers prefer it to foreign clay for these purposes, whereas others 

declare that they could not use it alone for semivitreous porcelain, 

as it would shrink badly. However, practically the whole output of 

the mine goes to china, porcelain, and other white-ware factories.

The following tests of the crude kaolin from the Sprucepine mine 

were made in the laboratory of the Bureau of Mines at Columbus, 

Ohio:

General physical tests of crude kaolin from Sprucepine mine No. 1, Mitchell

County, N. C.

Workability Very gritty; short; molds with difficulty;

ff dries well; no cracks.

Color of unfired clay______________________Cream.

Water of plasticity, in terms of dry clay___._percent 43.18

Air shrinkage by volume, in terms of dry clay____do__ 14.11

Air shrinkage, linear, calculated_________ .__do__ 5.00

Fineness test:

Residue, 20-mesh sieve___________i_____do__ 21.18 

Residue, 65-mesh sieve________________do__ 29.87 

Residue, 100-mesh sieve_______________do__ 2.28

Amount passing 200-mesh sieve_..____..__._____.._do__ 46.67
KAOLINS (WHITE RESIDUAL CLAYS). . 39 

Fire tests of crude kaolin from Sprucepine mine No. 1, Mitchell County, N. C.

Temperature 

v (°C.).

1,190 

1, 250 

1,310

Porosity 

(per cent in 

terms of burned 

volume).

45. 90 

47.20

44.87

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

10.7 

8.1 

14.0

Temperature 

(° C.).

1,370 

1,410

Porosity 

(per cent in 

terms of burned 

volume).

40.80 

29.10

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

22.3 

24.5

General physical tests of crude kaolin from oponiny of Sprucepine mine, half 

n mile east-southeast of Sprucepine, Mitchell County, N. C.

Workability_______ Very sandy; no strength ; corners tear. 

Color of unfired clay______________'_________ White. 

Water of plasticity, in terms of dry clay_____per cent_ 36. 69 

Air shrinkage by volume, in terms of di*y clay____do__ 16. 01 

Air shrinkage, linear, calculated_____ ____do__ 5. 7 

Moisture factor on dry basis___________do_ 1.3.17

Fineness test:

Residue, 20-mesh sieve_______________do__ 21. 58 

Residue, 65-niesh sieve_______________do__ 17. 39 

Residue, 100-mesh sieve______________do__ 1.16 

Residue, 200-mesh sieve_______________do__ 1.95

Amount passing 200-mesh sieve____________do__ 57. 95

Fire tests of kaolin from opening of Sprucepine mine, half a mile east-southeast 

of Spriicepine, Mitchell County, N. C.

Temperature 

(°C.).

1,190 

1,250 

1,310

Porosity 

(per cent in 

terms of burned 

volume).

35.7 

37.2 

36.0

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

14.7 

15.8 

16.8

Temperature 

(° C.).

1,370 

1,410

Porosity 

(per cent in 

terms of burned 

volume).

30.0 

18.7

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

23. 25 

27.6

/Sparks mine. The Sparks mine of the Harris Kaolin Co. is on 

the Carolina, Clinchfield & Ohio Railway about 2 miles northwest 

of Sprucepine and about midway between this village and Penland 

(fig. 10).

The deposit is on the slope of a hill several hundred feet above 

the washing plant, which is at the foot of the hill on the railroad. 

The mine was opened in the early part of 1914 and has been operating ever since. The main vein strikes about north. It is about 

100 feet wide and is known to extend 1,000 feet north and south. 

A spur branches from the main vein to the northeast. This spur 

ranges in width between 65 feet and 75 feet and is several hundred 

feet long. Another vein 47 feet west of the main vein and parallel 

to it is 30 feet wide. The reserve, calculated on the assumption that 

kaolinization has proceeded to the depth of 60 feet'and that 20 per 

cent of refined product can be recovered, is at least 60,000 tons.
40 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The mine is worked in the usual way by open cut and shafts. In 

August, 1918, two shafts about 20 feet deep were being operated. 

Other shafts from 45 feet to 50 feet deep had been abandoned because of water and the hardness of the rock at their bottoms. The 

overburden of red clay and rock fragments is from 6 feet to 10 

feet thick.

The crude kaolin is white and coarse. It contains abundant 

rounded quartz fragments, bunches of white and dark mica, quartz 

stringers, and much sand. On the walls of the shafts can be seen 

coarse quartz, quartz stringers, and dark and light mica flakes in 

bunches, forming streaks through the clay and abundant 'smaller 

plates of white mica scattered indiscriminately through the purer 

kaolin. Much of the darker mica is evidently badly decomposed, 

and some may itself be partly decomposed muscovite. A great deal 

of the white mica is fresh and in plates large enough to be of commercial value. This material is separated from the kaolin by hand 

and sold as punch and sheet stock.

The users of the Sparks kaolin are the same as those of the 

Sprucepine product, and the kaolin from both mines is practically 

the same in character. (See p. 38.) The potters that manufacture 

white ware and semiporcelain, who employ it in mixtures, report 

that as furnished to them in carload lots it burns to a very white 

body. It is used in the proportion of 10 to 16 per cent in the 

dry mix. It is also said to stand a very high fire and to be entirely 

satisfactory for the purpose to which it is put. The tile manufacturers employ it with New Jersey ball clay, flint, and feldspar, and 

as a uniform quality has been furnished, through the method 

of mixing the products from different pockets, it has given such 

good results that it has replaced completely the imported kaolin. 

The capacity of the plant is about the same as that of the Sprucepine mine.

The following tests of the washed kaolin were made in the laboratory of the Bureau of Mines at Columbus, Ohio:

General physical tests of washed kaolin, from Sparks plant, Sprucepine, Mitchell

County, N. C.

Workability _Short, sandy; corners tear; dries \yell (no cracks). 

Color of untired clay______________________White.

Water of plasticity, in terms of dry clay______per cent 44. 48 

Air shrinkage by volume, in terms of dry clay____do__ 20.20 

Air shrinkage, linear, calculated .-__________do__ 7. 3 

Moisture factor on dry basis______________do__ . 352 

Fineness test:

Residue, 20-niesh sieve________________do__ .00 

Residue, 65-ruesh sieve_______________do__ .00 

Resiflue, 100-raesh sieve_______________do__ . .00 

Residue, 200-mesh sieve______'.________do__ 2. 92 

Amount passing 200-mesh sieve___-__________do__ 97.08
KAOLINS (WHITE RESIDUAL CLAYS). 41 

Fire tests of kaolin from Sparks plant, Sprucepine, Mitchell County, N. C.

Temperature rc.).

1,190 

1,250 

1,310

Porosity 

(per cent in 

terms of burned 

volume).

39.6 

39.7 

37.97

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

18.1 

18.4 

20.3 >

Temperature (° c.).

1,370 

1,410

Porosity 

(per cent in 

terms of burned 

volume).

35.5 

28.5

Volume 

shrinkage 

(per cent in 

terms of volume 

of dry clay).

24.98 

28.0

FRANKLIN, MACON COUNTY.

Porter property. The Porter property was formerly worked by 

the Gurney Clay Co. as the Gurney mine. It is 4 miles northwest of Franklin and 3 miles east of Burningtown on lotla Creek. 

The shape of the pit, which has an average width of about 35 feet 

and is 400 feet long, indicates that the deposit is a narrow lens, but

as the width differs widely in different places the kaolin was.evidently pockety. Watts,17 in describing the mine when in operation, 

says that " the kaolinized dike forms an expanded lens, averaging 

about 200 feet in width and 300 feet in length already proved. 

* * * The lens consists of bands varying in kaolin content," but 

by mining the entire width of the dike a uniform product was obtained. At first the mine was worked by shafts, some of which 

were 100 feet deep, but this method 'proved so expensive that the 

open-cut method was adopted. The mine was worked about 4 years 

and produced about 250 tons of merchantable kaolin monthly.

It was abandoned in 1914 not, Mr. Gurney says, because of lack of 

material, but because of the lack of demand for kaolin in that year 

and because of a red stain in the output, which was caused by decomposed biotite. This stained material could not be separated 

from the clay in mining and therefore it had to be removed by hand. 

The cost of this cleaning was as great as the cost of mining. The 

time required for sorting limited the output of the plant to 250 tons 

monthly, though its capacity was 500 tons. 18 Mr. Gurney believes 

he now has a method for eliminating the stained clay, which should 

enable the deposit to be operated successfully.

The relations of the clay to the rock in the pit are now concealed 

by wash, but several branching dikes can be seen in the pit. There 

are also indications that the kaolin is crossed by horses of partly 

decomposed feldspar and coarse quartz, and where the walls are exposed there are small veins of kaolin in the country rock and seemingly fragments of rock in the clay. (See PI. Ill, A.) The fragments are probably parts of the country rock that have been surrounded by pegmatitic material. Bunches of muscovite are common

17 Watts, A. S., op. cit, p. 133.

18 Letter of Mr. J. W. Gurney of Aug. 14, 1918.
42 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

in the kaolin in many parts of the mine. In some parts the muscovite was so abundant that it was saved as a by-product. Biotite is 

also present but in smaller quantity, and it is generally associated 

with quartz. The waste heaps, which consist mainly of large fragments of quartz, indicate that much quartz was mined with the clay. 

The overburden Avas not more than 10 feet in thickness anywhere, 

and its average thickness was about 6 feet.

The crude clay was washed and pressed in a plant a few hundred 

yards from the pit and when dried was hauled by teams to Franklin. 

It was sold under the name " lotla brand " and was used by many 

of the potters in the Ohio Valley.

The buildings of the washing plant are still in good repair, but 

some of the machinery has been removed.

Jolinston property. The Johnston property, about 1 mile northwest of Franklin, which is owned by W. E. Johnston, of Sylvester, 

Ga., was formerly worked by the Southern Clay Co. It was operated only two years, and then the lease was surrendered, the plant 

was dismantled, and the company was dissolved. One of the causes 

of-the abandonment of the mine was the difficulty of handling the 

water. There were a number of openings on the northeast flank of 

Tremont Mountain, the largest of which was about 1 mile northwest 

of Franklin post office.

Little of interest can now be seen on the surface. Most of the 

workings have fallen in and their walls are concealed. About half 

a mile back of the main workings mica is now being taken from some 

of the old shafts and tunnels, and they have been cleaned out. 

Three of the openings expose kaolin about 10 feet in breadth, but 

much of it is badly stained near the surface. At increased depth, 

however, the staining diminishes, and at 25 feet underground the 

clay is uniformly white. It contains many bunches of large mica 

plates, which are now being removed for sale.

The main workings consist of an open pit 400 feet long and 50 

feet wide and a shaft 125 feet deep to water. The walls of the pit 

are nearly vertical, and its trend is a little north of east. The crude 

clay contained some coarse quartz and a great deal of fine mica, 

beside clumps of large plates, like those that are being mined farther 

northeast. This mica was saved and sold. The fine mica was separated during the process of washing the clay and was thrown aside. 

Large dump heaps on the site of the old plant are composed almost 

exclusively of fine white mica scales, which might possibly have been 

saved and sold as ground mica.

Mr. Johnston reports that about 4,000 tons of refined clay were 

sold and that it was used in making white ware and tile.

Cunningham property. Across a valley from the east end of the 

Johnston property, where the main dike of kaolin is reported to have
KAOLINS (WHITE RESIDUAL CLAYS). 43

disappeared, the dike reappears in the property of Mr. C. C. Cunningham, where it was worked through a number of shafts and pits 

as a source of mica. One shaft 25 feet deept is said to have penetrated 10 feet of overburden and 15 feet of clay. A boring in its 

bottom went through 35 feet more of similar clay. Two other 

shafts 25 feet deep and a third shaft 60 feet deep also exposed clay 

for their entire depth under the overburden. The depth of the 

kaolinization increases toward the east. Mr. Cunningham reports 

that borings and test pits outline a dike 22 feet wide and at least 

1,500 feet long. It' strikes a little north of east and dips about 

vertical. There is a great deal of mica in the clay and considerable 

quartz. It is possible that the kaolin and mioa might be mined 

together.

lotla mine. The lotla mine of the Franklin Kaolin & Mica Co. 

is 4J miles north of Franklin, on the west side of Little Tennessee

River, at lotla Bridge. The place is now abandoned. It was originally worked for mica and later for kaolin. Watts,10 in his description of the mine shortly after it was abandoned, says that the development consisted of 10 tunnels and 12 shafts and that some of the 

shafts were 120 feet deep. The dike had been mined for a length 

of 550 feet and for a width that ranged from 10 to 100 feet. 

Although layers of sugar quartz bordered the kaolin and a streak ran 

through the center of the dike, the crude clay contained very little 

quartz. A sample taken by Watts 19 from .one of the shafts yielded 

42 per cent of white kaolin of excellent quality.

If the property was ever worked for kaolin it was probably worked 

on only a very small scale, as there is no indication that any large 

quantity of material was ever removed from the ground. Moreover, 

all the dumps consist almost exclusively of mica. The most accessible part of the mine at present is a tunnel 150 feet long at the base 

of the hill, near the river. This tunnel for nearly all of its length 

is in a white clay, cut here and there by horses of rock and crossed 

by numerous streaks of muscovite in crystals and groups of crystals. 

The clay surrounding the crystals of mica contains a comparatively 

small amount -of quartz sand and abundant tiny flakes of white 

mica. Farther up on the hill slope six or seven other tunnels and 

a shaft penetrate clay, and near the top of the hill is a large tunnel 

through clay, mica, and quartz. Men who have worked on the 

property say that mica was much more plentiful near the top of 

the hill than lower down and that the quality of tlie kaoli-n was better 

at lower levels.

The large number of pits and shafts scattered over the property 

indicate that there are many small dikes of pegmatite and many

18 NVatts, A. S., op. cit., p. 133.
44 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

small pockets of kaolin. Some of the largest dikes appear to be 

promising.

j ALMOND, SWAIN' COUNTY.

Hewitt mine. The Hewitt mine, which is no longer in operation, 

was worked by a number of openings in a. belt that extends north 

and south at a distance of about 2 miles east of Almond (fig. 3) 

on the Murphy branch of the Southern Railway. The geologic associations here are unusual, for the wall rock is composed of graywacke and schists of the Great Smoky conglomerate, which is Lower 

Cambrian in age.20 The wall rocks of all other kaolinized pegmatites 

are formed of gneisses and schists of pre-Cambrian age. Six deposits 

are mapped. In 1905 the company was working the deposits 2£ 

miles southeast of Almond on the east side of the road between this 

village and Needmore. The clay was being taken from the top and 

the southern slope of a small ridge. -Test pits and a'short tunnel 

proved its extent for about 450 feet in a northerly direction. About 

a mile farther north is another deposit of kaolin and one-fourth 

mile west still a third one. Other deposits have been opened up by 

tests pits 2 miles southwest and 1| miles northwest of the Hewitt 

mine. At the locality last indicated there are two separate veins, 

and the kaolin in them is at least 50 feet deep. Later the deposit on 

the west side of the road was opened. This deposit was abandoned 

a few years ago, and the entire plant has been closed. At this place 21 

a dike 20 to 30 feet wide, which trended northward and dipped 75° 

E., had been removed for a distance of 275 feet and to a depth of 

40 to 60 feet. The pegmatitic material was incompletely kaolinized. 

The crude material yielded 20 per cent of a pale cream-colored refined kaolin.

BBYSON, SWAIN COUNTY.

Payne & Sullivan mine. The Payne & Sullivan mine, which 

is now abandoned, is 4 miles southwest of Brysoii, near Yalaka 

Creek. The openings are a short distance from those formerly 

worked by the Carolina Clay Co. at the head of Buckner Branch. 

The Carolina Clay Co.'s deposits were abandoned some years ago, 

but there are other dikes of kaolinized pegmatite in the neighborhood, and on one of these dikes the Payne & Sullivan mine was 

opened. At the old Carolina mine the dike is reported to have been 

16 feet wide. 22 It strikes N. 15° E. and dips 75° SE. It was rich in 

kaolin near the footwall but became progressively poorer toward the 

hanging wall, near which the dike material was nearly all sand. 

There were pockets of garnet-colored sand in the kaolin and streaks

20 Keith, Arthur, U. S. Geol. Survey Geol. Atlas, Nantahala folio (No. 143), p. 8, 1907.

21 Watts, A. S., op. cit., p, 119. 

- Watts, A. S., op. cit., p. -124.
KAOLINS (WHITE RESIDUAL CLAYS). 45

of wall rock. A sample taken from across the entire width of the 

dike yielded 22 per cent of a yellowish kaolin. The Payne & Sullivan mine, which has also been closed down for several years, is 

farther south, on the top of a steep slope. The buildings of the washing plant are still in fairly good repair, but all the machinery has 

been removed. One of the present owners says that the former 

lessees, Avho built the plant, operated the mine but a short time. They 

took out material that yielded about 250 tons of washed kaolin, 

of Avhich they shipped 100 tons. The remaining 150 tons is still in 

the storage sheds. When the mine was worked water was pumped 

320 feet. The crude clay Avas trammed 300 feet from the mouth of. 

the pit and sent down a chute to the refining plant at the bottom of 

the slope. The refined kaolin was hauled in wagons 1 mile to a 

private railroad known as the Yalaka Railroad and there loaded 

on standard cars. When the mine is reopened the crude material

will be sent from the old pit to the plant by a flume, the new openings will be joined by a tramway already partly constructed, and 

the product will be sluiced, together with that of the old opening.

There are now two main openings on the property and a number 

of shafts, tunnels, and test pits, nearly all of which expose excellent 

clay. The old pit is known as No. 1. A newer pit about half a mile 

farther northeast is known as No. 2. Wherever the clay is exposed it 

appears to be in a dike that strikes about N. 20° E., or rather a series 

of ramifying dikes that have a general northeasterly trend. In pit 

No. 1 the width of the deposit is 40 or 45 feet, in pit No. 2 about 20 

feet, and in a shaft and tunnel 375 feet south of pit No. 2 the maximum width of clear kaolin is 6 feet.

Pit No. 1 (PI. Ill, 5), which is 190 feet long and 40 feet wide, is 

an open cut along the strike of the dike. Its southeast Avail is granite. 

Its contact Avith the kaolin is vertical, so far as it has been uncovered. 

The nortliAvest Avail is composed of kaolin that is crossed by narrow 

horses of quartz and feldspar, but for 50 feet from the north end this 

Avail shoAvs an intermixture of small streaks of clay in an undecomposed mass of quartz and feldspar. The kaolin has been worked out 

to the bottom of the pit by open-cut methods to a depth of about 65 

feet from the original surface, except at the southAvest end of the 

excavation, in the northwest corner, where terrace-like benches have 

been left. These benches are about 40 feet above the bottom of pit, 

and at the time the mine Avas abandoned material was being removed 

from the terrace Avith the aid of two shafts. At the Avest end of the 

terrace is a cliff 40 feet high that is pierced by a tunnel. Both 

cliff and tunnel expose. kaolin that is traversed by many vertical 

streaks of quartz an inch Avide.

The clay in this pit is dense and Avhite. It is contaminated by little 

masses of partly decomposed feldspar, grains of quartz, soft crystals
46 HIGH-GRADE CLAYS OF TMti EASTERN UNITED STATES.

of partly decomposed muscovite, and hard black streaks of what is 

believed to be psilomelane or some other hard manganese oxide or 

hydroxide.

Pit No. 2 is a small open cut across a thoroughly kaolinized dike, 

about 26 feet wide, which exposes pure white clay. A tunnel, which 

has been drived into the face of the dike, extends back about 30 feet 

along its strike. Just beyond the end of the tunnel the dike ends in 

the face of a steep slope, which cuts it off. In the tunnel the relations

of the dike to the country ^rock 

are well shown. On its north 

wall the pegmatite sends irregular tongues into the granite and 

gneiss, as illustrated in figure 1, 

and on the south wall the same

________ _ ,, _______ . ^ relations are shown in a less

marked degree.

FIGURE 1. Relationj of kaolin and country Figure 2 shows the end and 

2° of tnen0paymr& SullTvan^mhie'^iiear Portion °f the side of a Cl'OSSCUt,

Bryson, N. c. which reaches the side of. a 6-foot 

dike of kaolin exposed in a shaft 375 feet south of pit No. 2. Here 

again the main dike fingers out into small veins that cut the country 

rock. Indeed, everywhere on the property the streaks of rock in the 

kaolin appear to be masses between tongues of kaolinized pegmatite. 

The crude clay of pit No. 2 is like that of pit No. 1, but it contains 

more coarse quartz in sharp fragments and very little sand and mica. 

In some places in the tunnel it possesses a distinct graphic structure. 

The quantity of clay in sight in this pit is estimated to be sufficient 

to yield 1,000 tons of washed kaolin. In this estimate no account has 

been taken of the amount of crude clay in 

the extension of the dike southwest of the 

"pit, since its length in this direction has not 

been explored.

Nearly all the openings between pits Nos. 

1 and 2 have exposed excellent white, almost porcelain-like clay, containing as visible impurities only here and there coarse 

flakes of mica and a few particles of sand. A 

boring in the bottom of the most promising 

shaft penetrated 39 feet of this kind of clay. 

Harris mine. The Harris mine, now 

abandoned but formerly worked by the 

Harris Kaolin Co., of Dillsboro, N. C., was 2-| miles north of Bryson, 

on the east flank of Sharptop Mountain. It was in a dike 40 to 60 

feet wide, in which there were many bands of wall rock. The dike 

trends N. 20° E., and it is crossed by faults at intervals of about 150

FIGURE 2. Relations of 

kaolin to mica schist at 

end of crosscut in a pit 

in the Payne & Sullivan 

mine, Bryson, N. C.
KAOLINS (WHITE RESIDUAL CLAYS). 47

feet. The dike is irregularly kaolinized and in some places is stained 

yellow. In 1913 the deposit had been about worked out.

A similar deposit was opened about 1 mile southwest but was 

abandoned after a few months' work and a new opening was made 

3 miles farther northwest, near Deep Creek. This place was later 

also abandoned. (See. fig. 3.)

83°30'

Abandoned mine Prospect Direction .of strike Strike and dip 

of bed of bed

FIGUUB 3. Map of kaolin deposits near Bryson, N. C. Abandoned mines: a, Hewitt; b, 

Payne & Sullivan ; c, Harris. Prospects: 2, Messev; 3, Hyde; 3i Everett.

PENLAND, MITCHELL COUNTY.

Property of the Bailey Lumber Co. The Bailey property, between Bear Creek and Toe River, contains two distinct deposits of 

kaolin in the neighborhood of Penland on the Carolina, Clinchfield 

& Ohio Railway. The western deposit was formerly worked as the
48 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Penland mine of the Harris Clay Co., of Dillsboro. This deposit is 

on the railroad about half a mile east of Penland station. It was 

abandoned a few years ago. The other deposit, which is known as 

the Firescald property or the " New deposit," is three-fourths of a 

mile northeast of Penland and about three-fourths of a mile from 

the old Penland mine.

The old Penland mine (fig. 10, p. 62) was worked by the Harris 

Clay Co. for 11 years and previously by the C. J. Edgar Co. The 

area covers 21 acres. The openings from which the clay was taken 

are on a hill slope about TO feet above the railroad. The washers 

were near the pits and the filter pressing plant was at the railroad. 

The deposit was worked by an open cut to a depth of 30 feet and by 

shafts to a further depth of 60 feet, The maximum length of the 

cut was 400 feet. At the depth of about 60 feet the rock became so 

hard that it had to be dynamited. The overburden was of the usual 

character and about 6 to 8 feet thick.

Although no definite wall can be seen, Watts says that at the time 

of his visit the southeast wall was well defined, but on the northwest 

side of the deposit " the dike material grades gradually into a hard, 

granitelike rock producing little or no kaolin." 23

On the map furnished by Mr. B. B. Westphalen, engineer of the 

Bailey Lumber Co., which owns the mineral rights, the strike of the 

eastern wall of the worked deposit ranges from northwest to north 

and the general trend of its greater length is north, though it turns 

to the east at its northern end. (See fig. 4.) The maximum width 

of the opening from which kaolin was taken is about 200 feet, but this 

space was not all occupied by clay, for the clay is traversed by several 

small horses of micaceous schist, and toward the north the dike is 

separated into two parts by a central horse of the same schist which 

has a width of about 80 feet. Moreover, the east wall of the pit is 

formed by the west side of another horse, or at any rate by a strip of 

schist which separates the worked deposit from another one that has 

not been opened but which has been tested sufficiently thoroughly to 

show that it occupies a large area. Whether the different deposits 

are united and represent parts of a single great branching pegmatite 

dike, divided by inclusions of rock, or whether they are on independent dikes has not yet been disclosed by the mining operations.

On the side of one of the shafts still open small dikes of pegmatite 

cut through the clay. They not only retain their structure but apparently have escaped kaolinization to such an extent that their feldspathic components are still recognizable. One of these dikes consists of quartz, perfectly fresh orthoclase and microcline, and here 

and there a flake of muscovite. It is 3 feet wide and dips 45° SE.

23 Watts, A. S., North Carolina Geol. Survey Bull. 53, p. 148, 1913.
KAOLINS (WHITE feESIDUAL CLAYS). 49

Samples of the crude kaolin taken by Watts from the workings 

yielded 22 per cent of cream-colored refined kaolin. When burned 

the product was a cream-colored porcelain which had a translucency

EXPLANATION

 Boring In kaolin 

6-28 First number indicates thickness of overburden;seconc/number indicates depth in kaolin

R Rock at surface

Boring in rock, 

mainly schist

+ Boring in pegmatite

and pegmatite sand 

w Stopped in water

. Line showing 

extent of clay

. Line showing limit 

of calculations

100 ZOO SOOFeeb

FIGURE 4. Map of borings at Penland mine, Penland, N. C.

of OJa>2 and showed a pale-green color under raw-lead and fritted 

glazes. The analysis of the commercial clay, as furnished by the 

Harris Kaolin Co., shows the following composition:

77412 22 5
50 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

Analysis of washed clay from Penland mine, Mitchell County, N. C.

Silica (S100_______________-__ 45.61 

Alumina (A1203 )_________________________ 38.63 

Ferric oxide (Fe2 03 ) 46 

Ferrous oxide (FeO)___________ 

Lime (CaO)____________________________ .08 

Magnesia (MgO)_____________ _ .08 

Potash (K2O) ___________________________ .90 

Soda (Na2 0)__________________ .66 

Titanic oxide (TiO2 )___________ Trace. 

Water (H2O)___________________________ 13.57

99.99

The clay from the Penland mine was used in the manufacture of 

white earthenware, semiporcelain, china, and tile. It was often substituted for the clay of the Sprucepine and Sparks mines. Like the 

kaolin of these mines, it was not used alone but in mixture with 

clays from Florida and Tennessee and English china clays.

Northeast of the old Penland openings and separated from them 

by a thin wall of rock lies an area^of about 4§ acres which has been 

explored by borings. The borings were made along lines that trend 

northeasterly and northwesterly and at intervals of about 50 feet. 

The overburden averages not more than 7 or 8 feet in thickness, and 

the depth of the clay penetrated ranges from 20 .to 45 feet. On the 

assumption that the average thickness of the clay is 30 feet and that 

the average yield of commercial kaolin is about 20 per cent of the 

crude tonnage, the tested area would yield about 70,000 tons of refined 

clay. However, the thickness of the kaolinized material is probably 

greater than 30 feet, and the yield of merchantable kaolin from the 

crude clay might run higher than 20 per cent.

The "New deposit," on the Firescald property, is three-fourths 

of a mile northeast of the old Penland mine. It has been tested by 

boring over about 15 acres by 200 holes at irregular intervals. The 

reserve on this area is estimated to be about 250,000 tons of commercial clay on the assumption that the whole area is occupied by kaolin, 

that the thickness of the deposit is 30 feet, and that the crude kaolin 

will yield 20 per cent of the refined product. The accompanying 

sketch map (fig. 5), furnished by the owners of the property, shows 

the distribution of the borings and the thickness of overburden and 

clay disclosed by them.

The character of the kaolin from the old Penland inine was very 

much like that from the Sparks mine.. The crude clay, however, 

contained a larger proportion of coarse rounded fragments of quartz 

and pieces of partly kaolinized feldspar and a similar proportion 

of mica. The refined kaolin was used, apparently with satisfaction, 

by a number of white-ware and china potteries and by makers of 

vitrified tile in the Ohio Valley.
KAOLINS (WHITE RESIDUAL CLAYS). 51

The material from the borings on the Firescald area is said to 

have been tested by several potters and other manufacturers and

Schist

<17-JO /b Pegmetite s-Ji"> xp 

*/*-.«»

EXPLANATION

Limits o^area underlain 

by kaolin

R Boring in rock, 

0 mainfy schist

p Boring in pegmatite and 

x pegmatite sand

 Boring in kaolin

6-zo First number indicates thickness, of 

overburden; second number indicates 

depth in Aao/in

FIGURE 5. Map of borings on the " Firescald " property, owned by I. C. Bailey, .near

Penland, N. C.

to be similar to the Hog Rock kaolin, but of course it has not been 

tried on a commercial scale.
52 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

UNDEVELOPED DEPOSITS. 

FKANKLIN, MACON COUNTY.

Of the many other deposits in Macon County in addition to those 

now worked or which have been worked in the past, only a few have 

been prospected in a-way to furnish any idea of their value. Most 

of them were originally opened as mica mines, and generally the 

value of the kaolin was completely disregarded. Moreover, most 

of them are so far from the railroad that the expense of marketing 

their product would be prohibitive, unless several of them in the

83°30'

83°30' 83°20

Mine Prospect Direction of strike 

of bed

Dip and strike

Vbed

FIGURE 6. Map of kaolin deposits near Franklin, N. C.

Abandoned mines:

d, Gurney.

e, Southern Clay Co.

f, lotla. 

Prospects:

1, Smith.

4. Lenoir.

5. McGuire.

6. Chalk mica mine.

Prospects Continued.

7. Eaby mica mine.

8. Porter mica mine.

9. Cunningham.

10. Moore.

11. Lyle.

12. Kasson mica mine.

13. Billings.

14. Ferguson.

Prospects Continued.

15. Frank.

16. Myers.

17. Sloan.

18. Sanders.

19. Rochester mica mine.

20. West.

21. Bryson.

same neighborhood should develop into much larger deposits than 

now seems probable. The positions of all the known deposits are 

indicated on the accompanying sketch map (fig. 6).

The two most favorable prospects are on the McGuire and the 

Ferguson properties.
KAOLINS (WHITE RESIDUAL CLAYS). ' 53

McGuire property. The McGuire property is about 3^ miles west 

of Franklin on the southwest slope of Tremont Mountain. The deposit is on a dike 18 feet wide that strikes northwest and dips 80° 

SW. Mr, J. H. Pratt made an examination of the property in. 1915 

and reported that at places over an area of about 2 square miles a 

number of openings have exposed kaolin, but only a few of them in 

commercial quantities. The largest of these openings are two tunnels. One of the tunnels is 72 feet long and runs N. 40° E. It 

penetrates kaolin for 22 feet and then enters country rock. At the 

contact of the kaolin and country rock a drift extends N. 100° E. 

for a distance of 15 feet. The original pegmatite has been almost 

completely kaolinized; the only unaltered rock observed in the dika 

is a little feldspar that is associated with a band of quartz. In the 

kaolin there is a little scattered mica and a few nests of " decomposed 

garnet." A second tunnel 200 yards S. 50° E. from the first one 

starts at the contact of the dike and the country rock and follows 

the hanging wall for 108 feet. At a point 56 feet from the mouth 

of the tunnel a crosscut that runs N. 30° E. crosses the dike, which is 

18 feet wide. By assuming that the deposit is continuous between 

the two dikes and that kaolinization has extended to a depth of 100' 

feet, Pratt estimates that 18,000 tons of washed kaolin is present, 

provided the yield is 30 per cent of the crude clay.

About 900 feet S. 60° E. from the tunnel there is a shaft 20 feet 

deep that cuts 12 feet of kaolin like that in the tunnels. Kaolinized 

material is exposed east and west of the shaft for a distance of !{; 

miles, but at only one place, a tunnel in the Avoods west of the shaft, 

do_es the quantity seem to be large. The tunnel is cut into a hill 

for 120 feet, and at this point it encountered the footwall of a 

dike, which was again exposed in a shaft of 30 feet or more above 

the tunnel. At the extreme western end of the property a shaft 

on the top of a little hill that rises 60 feet above a creek struck 

clay at a depth of 30 feet. Another shaft 86 feet from this one 

reached clay at.the same elevation, and several small pits exposed 

it in other places. These openings indicate the presence of a mass 

of kaolin about 100 feet broad, but its other dimensions were not disclosed. Some of the kaolin is stained by iron oxide, but otherwise 

it is good.

Mr. McGuire reports considerable boring on the property since 

Mr. Pratt's visit, but he can not give details as to the results.

A washing test of the material in the dikes yielded 42 per cent 

of a cream-colored kaolin, which was analyzed as follows:24

2< Watts, A. S., op. cit, p. l.T?
54 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

Analysis of washed kaolin from McOuire property, near Franklin, N. C.

Silica (Si02 )___________________________ 46.35 

Alumina (A12 03 )__________________________ 39.00 

Ferric oxide (Fe2 03 )______________________ .30 

Lirne (CaO) _ ___1_____________________ Trace.

Magnesia (MgO)__________________________ Trace. 

Soda (Na2O)___________________________ .00 

Potash (K,0)___________________________ .50 

Titanic oxide (TiO2 )_______________________ Trace. 

Water (H2 0j____________________________ 14.00

No.13.

100.15

Mr. Lillibridge, of the American Encaustic Tiling Co., for whom 

some of the boring was clone, says in a letter to the writer that the 

N NaKe kaolin is of a sufficiently high standard 

M Nol%0- to meet the requirements of wall-tile 

manufacturers.

The kaolin can be economically 

mined, as there is a good supply of 

water for all purposes and a down 

grade to a good road.

Oo t ->-\\ Ferguson property. The Ferguson

property is 2£ miles northeast of 

No7 °^' ' -Franklin and 1 mile southwest of 

No5 Dean. The property has been explored 

. Oj°' °15 ' by a tunnel that runs northeastward 

The figures showing feet indicate depths into the side of a ridge. The tunnel

into clay > ~ 

Dotted lines represent horizontal boring? CUtS 95 feet Of kaolin in Which there

o so- 100Feet ^s a 20-foot horse of partly altered

feldspar and streaks of quartz. Near 

FIGURE 7.-Map of borings on th d f t] t j ^ 

Ferguson property, near 

Franklin,, N. c. cut about 50 feet long which is all in

excellent clay. That on the northwest side of the tunnel contains 

considerable coarse mica that is probably merchantable. There is 

also a little feldspar that might prove of value. Near the end of 

the tunnel there is a shaft 14 feet deep, and in the bottom of this 

shaft a boring 20 feet deep reaches hard rock. As the mouth of the 

tunnel is 45 feet below the top of the ridge, it is safe to assume that 

the depth of the kaolinization is TO feet.

A sketch showing the distribution of the borings with reference to 

the tunnel is given in figure 7. It is evident that these borings do 

not outline the deposit. On the assumption that the deposit has 

been proved for a length of 200 feet, a width of 48 feet, and a depth 

of 60 feet, and that 25 per cent of the kaolin in the crude material 

is recoverable, the quantity of refined kaolin is about 6,500 tons.
KAOLINS (WHITE RESIDUAL CLAYS). 55

The kaolin in the tunnel is snow-white and free from grit and 

visible impurities of all kinds, except the large flakes of mica already 

referred to. That on the old dump at the mouth of the tunnel is 

slightly stained.

The deposit, where it is exposed, is near the top of a slope that rises 

70 feet above its base, so that mining would be comparatively easy. 

Abundant water is available near by. It. could be pumped to the 

top of the ridge and used for sluicing the crude clay to a washer 

situated in the valley 70 feet below.

DILLSBORO, JACKSON COUNTY.

Property of the Harris Kaolin Co. Two other deposits near Dillsboro (fig. 8) have been tested by boring, but have not otherwise been 

explored. One of these, deposits, known as the Ashe property, is 

about 5 miles southeast of Dillsboro, in the gap in the mountain 

about a mile west, of Painter. Nothing definite is known about 

the deposit except that it was once opened by a pit on a vein reported to be about 15 feet wide. Borings indicate that the area 

underlain by kaolin is 200 feet long by 21 feet wide and that it may 

produce about 10,000 tons of refined kaolin.

The other explored deposit is about half a mile south of the plant 

of the Roda mine, on the south side of a hill. The area underlain 

by kaolin is 400 feet long by 50 feet wide. It contains about 15,000 

tons of kaolin, which resembles that from the Hog Rock mine.

The kaolin from both these deposits can easily be prepared for 

market at the plant of the Harris Kaolin Co. near Webster.

The total reserve of the four properties of the Harris Kaolin Co. 

in Jackson County is estimated by the company to be between 40,000 

and 50,000 tons of refined material.

BETA, JACKSON COUNTY.

Boss property. The only promising prospect in Jackson County, 

besides those already mentioned, is near Beta, about half a mile 

southwest of the railroad station, on the west slope of the hill south 

of the railroad. It is now known as the Boss prospect, but it is 

probably the same as the Buchanan prospect described by Watts.'5 

The principal openings are about 400 feet above Scott Creek. They 

comprise a number of test pits near the top of a ridge that trends 

northeasterly and several tunnels and shafts below these on its western slope. The only one of the tunnels that is now open to inspection is more than 200 feet long and has a right-angled turn about 

125 feet from its mouth. Watts reports several dikes at this place 

which range in width from 10 to 18 feet, strike N. 40° E., and dip

58 Watts, A. S., op. cit., p. 154.
56 HIGH-GEADE CLAYS OF THE EASTERN" UNITED STATES.

80° NW. The upper of the two principal dikes has been opened 

by a few test pits and the lower, one-eighth of a mile farther west, 

by shafts 25 feet deep and by two tunnels. Both dikes contain 

lenses of garnet-colored sand mixed with altered biotite. Samples 

taken from the lower dike yielded 40 per cent of kaolin that had a refractory value above 1,730° C. Its analysis is given on page 25.

83'ZO'

83'20'

Contour, interval 500 feet 

Dalam is mean sea. level

EXPLANATION

Mine Abandoned 

mine

Prospect Vashmd plant 

of Roddrmine

FIGURE 8. Map of kaolin deposits near Dillsborp, N. C.

Active mines : Abandoned mines Contd. -Contd. Prospects Continued.

A, Hog Rock. i, Springer. 27, Cowan.

B, Roda. /, Harris. 28, Ashe.

Abandoned mines: Prospects: 29, Forest Hill mica mine.

U, American Land & De- 23, Cagle Gap mica mine.' 30, Harris.

velopment Co. 24, Hall. 31, Long mica mine.

h, North Carolina Mining 25, Ross. 32, Wayehutta mica mine.

& Manufacturing Co. 26, Love.

The walls of the main tunnel are composed of white clay and 

are crossed by many bands of quartzose pegmatite, 3 feet to 4 feet 

wide, running in all directions. The pegmatite is thoroughly decomposed, but its content of quartz is so high that much barren rock 

would have to be removed in mining. In most places the kaolin 

contains considerable quartz and mica, but some of the masses between the bands of pegmatite consist of nearly solid, dense kaolin. 

At 200 feet from the mouth of the tunnel is a pit that was not
KAOLINS' (WHITE RESIDUAL CLAYS). 57

crosssd, but in the walls beyond there appeared to be wide, clean 

exposures of clay.

The best samples taken from the best pockets differ from samples 

of the average material of the walls, exclusive of the pegmatite veins, 

only in being almost free from mica and coarse grains of quartz. 

The average sample is lumpy, but the selected samples are nearly 

uniform in structure. Both are gritty, but the grit in the better 

sample is so. fine as to be scarcely visible, whereas that in the average 

sample consists of quartz grains one-eighth to one-quarter inch in 

diameter. Moreover, little groups of these grains together with 

mica flakes are aggregated into lumps. The cracks between the 

grains are badly stained by iron compounds that have infiltrated 

and oxidized, and therefore the crushing of the lumps seriously discolors the clay. The better samples are pure white when first taken, 

but upon standing in a dry atmosphere they turn pinkish or pinkish 

yellow, possibly through the oxidation of iron salts. These samples 

contain no visible impurities except tiny grains of sand.

Unquestionably deposits exposed by the pits and tunnels on this 

hill contain a great deal of kaolin, but it is very doubtful if any of 

the deposits are large enough to be worked economically. Besides 

the deposits described above a dozen others in the vicinity of Dillsboro and Webster have been mentioned in the different reports on 

the clays of the State but none of them are valuable at the present 

time. A few have been worked and abandoned after a year or two. 

Others have been prospected but not worked, and still others have 

merely been sampled. The locations of all those in which kaolin is 

known to occur are shown on the sketch map (fig. 8).

ETOWAH, HENDERSON COUNTY.

Valentine property. Mr. G. H. Valentine, of Hendersonville, reports a deposit of kaolin in Henderson County close to the west bank 

of French Broad Eiver, 1£ miles north of Etowah. The deposit is 

known to be from 50 to 75 feet wide and more than 10 feet deep, 

but its length has not been determined. Several small excavations 

have been made in it, and the grade for the public highway cuts it. 

Most of the clay is white, but in some places it is pink or salmon 

colored. The deposit is a few hundred yards from the river and 

about 50 feet above it, and a mountain brook near by might furnish 

all the water needed in mining. A road 2 miles long, which is used 

for heavy hauling by trucks to a point less than one-fourth of a 

mile from the deposit, leads to Etowah, on the Toxaway branch of 

the Southern Railway.

The sample furnished by Mr. Valentine is a white gritty powder 

that becomes only slightly sticky when moistened with a little water. 

When shaken with water the mass rapidly separates into a sediment
58 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

and a thin fluid of a very pale gray, almost white color. The sediment consists of small sharp-edged transparent quartz grains and 

larger masses of grains that are cemented by kaolinite, particles of 

material stained by limonite, and a few fragments of other substances, some of which are organic. The unwashed powder is composed of comparatively few small flakes of kaolinite, fragments of 

rosettes and wormlike aggregates of the same mineral, many fragments of clear, colorless quartz, and flakes and groups of grains and 

a few other particles that may be partly kaolinized feldspar. A few 

of the quartz grains are large, measuring about 0.3 millimeter in 

their longest dimensions, but most of them are between 0.05 and 

0.07 millimeter.

The sample is composed mainly of a fine quartz sand together with 

a comparatively small proportion of kaolinite. Whether the material is residual or sedimentary in origin can not be determined from 

its appearance. If it is sedimentary, its components have not been 

carried far, for the quartz grains show little or no evidence of rounding. The area that contains the deposit is underlain by Henderson 

granite, which, according to Keith,28 " upon complete decay * * * 

produces a yellowish or reddish clay, which is frequently leached 

out nearly white. This is mixed with sand and fragments of rock 

on the mountain sides and is of no great depth."

Material of this kind partly assorted by water might yield a product resembling the sample, which is very much like the samples 

from Richmond and Montgomery counties in North Carolina and 

from the vicinity of Abbeville in South Carolina.

HAZELWOOD, HAYWOOD COUNTY.

Herren property. A deposit in Haywood County that has not 

hitherto been described is well up toward the top of a spur at the 

southwest end of Lickstone Mountain, on the property of J. P. 

Herren, of Waynesville, about 4£ miles south of Waynesville and 

3-| miles southeast of Hazelwood. There are several openings on the 

property, but they are now filled with debris and difficult to study. 

The largest opening furnishes a vertical section 12 feet long and 

originally exposed a surface 12 feet high, including 7 feet of kaolin. 

The lower portion of the section is now covered by fallen material. 

The part now visible shows an almost horizontal contact between 

mica schist and a very quartzose stained kaolin that exhibits the 

structure of a pegmatite. It is cut by little quartz stringers and contains masses of decomposed black mica, flakes of decomposed white 

mica, and sharp-edged fragments of quartz. (See fig. 9.) Other

. M Keith, Arthur, U. S. Geol. Survey Geol. Atlas, Pisgah folio (No. 147), p. 4, 1907.
KAOLINS (WHITE RESIDUAL CLAYS). 59

openings a few hundred yards south of this pit show the same cap 

rock and the same kind .of kaolin. At a distance of about 12 feet 

from the foot of the cliff in the larger pit "is an exposure of mica 

schist, which is apparently the footwall of the dike. Accordingly, 

both footwall and hanging wall must be nearly flat, and their contacts 

with the dike are very irregular. When the pit was opened a little 

mica was taken from the neighborhood of the footwall. No kaolin 

was mined nor were any tests made of its quality. Samples obtained

Fill

\z'

A B

FIGURE 9. Herren pit, Hazelwood, N. C. A, Vertical wall of pit; B 

Cross section of pit. a, Muscovite-biotite schist; I, Kaolin.

from that portion of the vein now exposed would give no fair idea 

of its value.

The deposit is not near the railroad, but there is abundant water in 

the vicinity for washing.

BIBDTOWN, SWAIN COUNTY.

Cole & Black property. The Cole & Black prospect is about 7 

miles northeast of Bryson and three-fourths of a mile southeast of 

Birdtown, about half a mile east of Oconalufty River and the Appalachian Railway along its side. A. B. Cole, of Bryson, N. C., is the 

representative of the owners. The location has been prospected by 

a series of test pits and several shafts.

The largest opening is a shaft 12 feet in diameter and 27 feet deep, 

at the bottom of which is a boring of equal depth. The upper, 12 

feet of the shaft passes through a clay overburden and a mass of 

dark schist (probably a micaceous hornblende gneiss), which is 

folded into a syncline that can be traced eastward for some distance. 

The schist forms a capping above the kaolin and separates it from 

the clay overburden on the surface. Below the capping the kaolin 

is continuous to the depth reached by the auger. In general the 

kaolin is very white, but it is streaked with yellow and red stains 

near the top. Farther down it is said to be free from stains, but 

only its upper part can now be seen. It contains also coarse fragments of quartz and is crossed by comparatively large horses of 

that mineral. Sand and black mica are also present in it, but not 

in large quantities. The strike of the bottom of the syncline is N.
60 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

20° E., which is also the strike of the kaolin deposit indicated by 

the lines of pits. Where wall rock can be seen it dips southeastward at a high angle. Three other shafts and a tunnel mark the 

extension of the dike for at least 300 feet along its strike.

A little farther to the west is another series of openings, consisting of several test pits and two shafts, one 20 feet deep and the 

other 57 feet deep. The walls of these shafts are not visible, but 

their dumps show considerable sandy kaolin mixed with quartz and 

black mica. The deposit marked by this series of openings is parallel to the more easterly one and is evidently on an independent 

dike.

Although very little definite information can be gathered from 

the prospecting, it has shown the presence of a great quantity of 

kaolin. However, it has "not shown that the kaolin is in deposits 

large enough to be of commercial value. If systematic borings 

around the first shaft described above should outline a reasonably 

large deposit it might be worked economically by tramming 500 

yards, sluicing to a washer placed a little below the mine, and 

sluicing by gravity to a settling plant on the river 400 yards distant. 

It would be necessary to pump water about 200 feet to the mine and 

to flush the sluice leading to the washer.

MICAVILLE, YANCEY COUNTY.

Thomas-prospect. The Thomas prospect is a deposit that is being 

held in reserve by the Harris Kaolin Co. It has been tested by 

tunnels and shafts, but has not yet been exploited. It is expected 

that the clay will 'be refined at the Lamonti plant. The deposit is 

about 1| miles north of Micaville and 1 mile northwest of Lamonti. 

(See fig. 10.) The dike that contains the deposit strikes N. 45° E. 

According to Mr. Hise, the place has been 'thoroughly explored, 

revealing two dikes 60 and 175 feet wide and at least 1,000 feet long. 

Shafts and tunnels on the property have uncovered good kaolin, 

which contains a little sand and white and black mica and which is 

crossed by streaks of red mica that is apparently of the proper size 

and in sufficient quantity at greater depths to be commercially valuable. The deposits are also penetrated by horses of rock. The overburden ranges in thickness from 4 to 12 feet. If half of the clay 

can be removed, the yield of the deposit in refined kaolin may be 

50,000 tons.

The kaolin is thought to be of the same quality as that at the 

Wilson mine. A flume line from the property to Lamonti has 

already been surveyed, and electric line poles have been set up, but 

the wires are not strung. Water will be pumped from a creek to the 

mine, 150 feet higher, and the slip will flow all the way to the plant 

by gravity.
KAOLINS (WHITE RESIDUAL CLAYS). 61

Smith prospect. Several other prospects in the vicinity of Micaville, besides those mentioned, are promising sources of kaolin, and 

a feAv others are known but have not been thoroughly tested, so 

that it is not possible to give any safe estimate of their value.

Perhaps the most promising prospect is that on the property of 

Misses E. E. and M. P. Smith, of Asheville, N. C., and Mrs. George 

R. Calvert, of NCAV York. The deposit is 1£ miles east of Burnsville, 

alongside the Black Mountain Railroad. It was formerly worked 

for mica, and during the search for that mineral numerous holes were 

dug and. a shaft 40 feet deep was sunk. The shaft cut 3 or 4 feet of 

overburden and about 35 feet of kaolin. It was abandoned because 

of caving. A tunnel 100 feet long also exposed kaolin. Abundant 

water is available for the use of a mine and washing plant. The 

place has not been visited. The description given here is based on 

the statements of Miss M. P. Smith.

Watts 27 states in his description of the deposit that it is on a dike, 

25 to 35 feet in width, which strikes N. 20° E. and dips irregularly. 

The kaolin incloses lenses of semikaolinized material, but on the 

whole the dike is well kaolinized. Tunnels connected by a crosscut expose nearly the entire width of the dike and show 6 feet 

of well-kaolinized pegmatite along its west wall and 9 feet of semikaolinized material and 20 feet of kaolin adjoining its east wall. 

Test pits indicate that the dike may extend about half a mile.

The samples seen by the writer are pure white and contain very 

little grit. Large lumps break with a distinct cleavage and 'thus indicate that the part of the dike from which they came was an almost 

pure aggregate of coarse-grained feldspar. Close inspection reveals 

a few grains of quartz sand, a few flakes of fine mica, and a few 

minute spots of some yellow earthy material. Under the microscope 

the largest quartz grains seen had diameters of 0.1 to 0.15 millimeter. 

The mica is in very tiny flakes and shreds whose diameters are not 

more than 0.025 millimeter. A few stained clumps of kaolinite were 

the only other constituents noted. The sample is an especially pure 

kaolin. Offers are said to have been made to mine the kaolin on a 

royalty basis, but the amount of royalty tendered was not attractive 

enough to the owners to induce them to sign a contract. If the prop-' 

erty is worked it may produce mica as a by-product.

MITCHELL COUNTY.

No properties in Mitchell County, besides those described on pages 

36-41 and 47-51, have ever been worked for kaolin on a commercial 

basis. There have, however, been many workings for mica, and in 

some of these considerable kaolin of good quality has been encountered. In addition a few deposits have been explored for kaolin

27 Watts, A. S., op. cit, p. 127.
p

3 §

oH-b

Sf o

O> Ks

O ^ 

p ^

- o

O cn c^- 

i '

II

Active mines:

G, Sprucepine.

H. Sparks.

D, Wilson.

E, Wyatt.

F, Job Thomas. 

Abandoned mines:

k. Clay Products Co.

I, Penland mine.

m, Old Sprucepine mine. 

Prospects:

42. Smith.

43. Thomas.

44. Howell.

45. Bcnner mica mine.

46. Flukin Ridse.

47. American Mica & 

Mining Co.

48. 49, McKinney.

50. Young.

51. Snow Creek.

52. Fircscald.

53. Tolley mica mine.

54. Wiscman.

65, Ollis.

56, Wiseman.

Strike of 

bed

Mine Aband

FIGURE 10. Map of kaolin deposits in Mitchell, Y

Strike and dip 

of bed
KAOLINS (WHITE RESIDUAL CLAYS). 63

Ohio Railway a deposit of kaolin is said to occur in a dike that strikes 

a little east of north and dips about 75° NW. It has been tested by a 

shaft, which penetrates excellent kaolin to a depth of 35 feet, and by 

borings at intervals of 20 feet. Most of the borings go to a depth of 

40 feet in clay. The Harris Kaolin Co., owners of the mineral rights, 

declare that the deposit is at least 300 feet long by 150 feet wide, and 

that the clay is much like that at Sprucepine. The estimated reserve, 

calculated on the basis of a 20 per cent yield, is about 20,000 tons of 

refined kaolin. The slip could easily be delivered at the railroad by 

n flume.

The Flukin Ridge deposit consists of a series of openings that were 

originally made in the search for mica. They are on the top of 

Flukin Ridge, a northwest spur from Burns Mountain, 2£ miles 

southwest of Bakersville and about 1£ miles east of the plant of the 

Interment China Clay Co., on the Carolina, Clinchfield & Ohio Railway, at Interment, about 2 miles south of Toecane, with which it may 

readily be connected by a flume. Watts 28 states that the area contains 

a large number of dikes of partly decomposed pegmatite, which strike 

N. 50° E. and dip 65° SE. He also states that tunnels and shafts 

had been dug over an area a half mile long and one-eighth of a mile 

wide, and that 

at one point a considerable quantity of fine white kaolin is encountered. There 

are, however, occasional streaks of fresh feldspar and on all sides of the lens 

there is semikaolinized material; these facts justify the assumption that the 

kaolin is merely an isolated lens and would not justify the equipment of an 

extensive outfit for handling it, although the presence in the neighborhood 

of other isolated kaolin deposits would justify the sinking of shafts and the 

removal of this kaolin to a central washing plant.

In 1915 the place was explored for kaolin by extending old tunnels and by boring. At present the shafts are inaccessible and the 

tunnels are accessible for only short distances from their openings. 

The borings are not mapped. However, representatives of the Intermont China Clay Co., which contemplates working the place, report that the borings indicate a vein 200 feet wide, including a few 

horses of rock, and 900 feet long. Near its southwest end a rock 

wedge penetrates it and splits it into two parts, the dimensions of 

which are not known. The best clay is said to lie near the footwall, 

where it is white, dense, and free from streaks of mica. Elsewhere 

there are streaks of mica and quartz, which increase toward the footwall. In one of the shafts put down near the center of the deposit 

fairly good kaolin shows in the walls to a depth of 72 feet, and a 

boring made in its bottom penetrates, 11 feet more of good clay. A 

crosscut 46 feet from the bottom of the shaft toward the footwall is 

also all in kaolin. The quantity of refined clay that the deposit will

28 Watts, A. S., op. cit., pp. 108. 121.
64 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

yield is estimated at about 75,000 tons. It is proposed to sluice the 

slip to the settling plant at Intermont, oh the railroad. The length 

of the flume required would be about 3^ miles.

A sample was taken from the walls of a tunnel, near the footwall 

of the dike, where the clay is much interrupted by streaks of mica. 

If the deposit is worked mica may be obtained as a by-product.

Tlie other properties in this vicinity that might contribute to a 

washer on a flume -line between Flukin Ridge and Intermont are 

the old Benner mica mine, the Sinkhole Ridge prospect, and the 

P. H. Howell prospect. The first two mentioned are on Sinkhole 

Ridge, 3 miles southwest of Bakersville and about three-fourths 

mile southwest of Flukin Ridge. Neither of these places was seen.

JEFFERSON, ASHE COUNTY.

Bare property. The Bare deposit is known only by its samples. 

It is on the property of Jesse Bare, sr., near the mouth of Dog 

Creek, 4| miles east of Jefferson, in Ashe County. It has been 

opened by two trenches, 2 feet deep, in solid clay. One trench is 

10 feet long and 2-| feet wide and, the other 6 feet long and 4 feet 

wide. The overburden is 3 feet thick. Mr. Bare writes that the 

deposit is on top of a flat smooth ridge, and that it occupies about 

an acre, as is indicated .by the distribution of the lumps turned up in 

plowing.

The sample sent is in very hard white granular porous masses 

that absorb a great quantity of water without disintegrating. Careful examination with a hand lens reveals many transparent colorless quartz grains in a white structureless cement. Here and there 

a larger quartz grain is embedded in the mass, and there are a few 

little groups of stained grains. When shaken with water and

allowed to stand for a few minutes a sediment settles that consists 

almost exclusively of grains of quartz and a white opaque material 

that is probably kaolinized feldspar, as the particles are bounded 

by planes which appear to be the result of cleavage. No other constituents are observable when the crushed kaolin is viewed under 

the microscope. The quartz grains, which are jagged in outline, 

range from 0.3 to 0.15 millimeter in diameter. They are comparatively few as compared with the grains of kaolinized feldspar. 

These grains of feldspar are almost nonpolarizing. They are commonly straight edged, but a few of them are subangular. The 

smallest particles are plates of kaolin. They are not very abundant. 

A few wisps of muscovite are noted in places, but they are very rare. 

The appearance of the material in the hand specimen and under 

the microscope indicates that it comes from an incompletely kaolinized, very feldspathic pegmatite.
KAOLINS (WHITE RESIDUAL CLAYS). 65 

KAOLINS IN THE PIEDMONT PLATEAU REGION.

Although all the kaolin deposits of North Carolina that are now 

being exploited are in the mountain district, nevertheless the deposits that have been found in the Piedmont Plateau (PL I) may be 

of commercial value when they have been thoroughly explored. A 

few of these deposits have resulted from the alteration of pegmatites 

and are similar to the deposits in the mountain district. Others have 

apparently resulted from the alteration of granites, of schistose 

feldspathic rocks, or even of slates. The deposits that have been 

derived from slates are of no great commercial value. Some of 

these deposits may produce, material that can be utilized for some of 

the purposes to which kaolins are adapted, but most of their material 

is so impure that it will not burn white. They are mentioned in 

the following pages only where their description is necessary to 

complete the discussion of certain properties on which white-burning 

kaolins occur.

The kaolins that are derived from granites and schistose feldspathic rocks are as a rule less compact than those that are derived 

from pegmatites. They are generally fine grained, powdery, and 

very quartzose. They rarely contain large fragments of quartz or 

large pieces of partly kaolinized feldspar. They cover comparatively broad areas, and if derived from schists they commonly occur 

as layers between layers of very impure clay or of only slightly 

decomposed rocks. The dips of the layers may be high or low, depending upon the attitude of the beds of which they are a part. 

If the original-layer of rock was thick the' thickness of the kaolin 

will depend upon the depth to which kaolinization has proceeded. 

If the original layer was thin the resulting layer of kaolin must also 

be thin. In prospecting it is important to determine the thickness 

of deposits of this kind by actual test or by calculations based upon 

observations of dip.

The processes by which the granites and feldspathic schists were 

changed to kaolin were the same as those that changed the pegmatites, and therefore they need no special discussion. (See p. 20.)

KAOLINS FROM PEGMATITE AND GRANITE. 

BESSEMER CITY, GASTON COUNTY.

Property of J. A. Smith. The only kaolin deposits on the Piedmont Plateau that have been visited and that are believed to be 

derived from pegmatite or from granite are on the property of Mr. 

J. A. Smith, of Bessemer City.

Two openings are inside the city limits. One of these openings 

is a shaft 30 feet deep near the railroad station. It is now boarded 

up, but the walls can be seen to be composed of white clay that unuer77412 22 G
66 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

lies an overburden of about 7 feet of red clay. The sample, which 

Mr. Smith says was taken from the side of this shaft 18 feet from the 

surface, is a white kaolin that dries into a powdery mass. It 

contains some sand, a little mica, and the usual black streaks. A 

boring in the bottom of the shaft went down 12 feet farther, all in 

clay. Wells in the vicinity of the shaft all passed through similar 

clay. Several carloads of material were shipped from these openings, two of which went to a tile manufacturer, who made from the 

kaolin a cream-colored translucent product.

About 1,800 feet northeast of the shaft is another opening, which 

is now partly filled. It is a pit that shows on its wall a 16-foot 

band of kaolin, which is said to be separated from another band 10 

feet wide by a horse of red clay. Mr. Smith declares that borings 

indicate the existence of a belt of high-grade clay 300 feet wide, 

interrupted by horses of impure clay. The west wall of the deposit 

is as far as can be seen decomposed gneiss, as are also the horses of

200 feet

FIGURE 11. Longitudinal section of kaolin deposit near 

Bessemer City, N. C.

clay. The other walls are not visible. Borings a short distance 

from this pit are reported to have outlined a dike 160 feet wide. 

Nearly all the holes that penetrated kaolin showed it to extend to 

a depth of at least 35 feet. The structure of the clay in the pit 

suggests a residual deposit. It is crossed by little veins of quartz 

and b.y streaks of yellow stain. Mr. Smith believes he has discovered 

a series of dikes from 10 to 200 feet wide which strike N. 22° E. 

and dip vertically. There is no reason to doubt this conclusion, 

though no evidence was at hand to confirm it.

Another deposit, 1|, miles northeast of the city, near Long Creek, 

is of an entirely different character. It is exposed in a long gully 

from 10 to 30 feet deep. At the upper end the floor of the gully contains numerous large granite boulders. Farther south these boulders 

become friable, and beyond, where the gully becomes deeper, they 

are partly disintegrated and covered with a layer of clay. Still 

farther south the gully is deep and clay extends to its bottom. The 

granite ends in a steep slope over which a little wet-weather stream 

cascades (fig. 11). About 100 feet downstream from the last boul-
KAOLINS (WHITE RESIDUAL CLAYS). 67

der is an exposure of schist, which is separated from the granite 

by a deep deposit of white clay. At the bottom of the gully and 

in its walls at this place some of the kaolin seems to be a sedimentary 

clay, but on the whole it presents the texture of the granite that is, 

it contains quartz grains of the same sizes and shapes as those in 

the granite, and a few streaks of black earthy substance that may 

be some decomposed ferruginous mineral, such as biotite, augite, or 

hornblende. The components are arranged like those of the granite, 

the feldspar in'the rock being replaced by kaolinite in the clay. The 

conditions suggest a concentration of kaolin at the base of a granite 

slope by the washing of the decomposition products of the granite 

into a depression between granite and schist. The deeper kaolinization of the granite at this point and the consequent development of 

the steep slope are probably due to the presence here of the contact 

surface between granite and schist. Plainly the greater part of the 

kaolin is a residual deposit that is the result of the decomposition of 

granite. Where the overburden of red clay is visible it is 6 to 7 feet 

thick.

A sample of the clay was taken from a hole on the east side of the 

bottom of the gully and from a strip of its west wall 25 feet long. It 

is a plastic white kaolin containing grains of quartz, feldspar, white 

mica, a few specks of black earth, and a few yellow streaks.

There is unquestionably a large quantity of kaolin at this locality, 

but it is probably irregularly distributed. Whether it is capable of 

being worked economically can not be determined without a thorough 

exploration. Water is abundant for washing, and the locality is only 

1£ miles from the Atlanta branch of the Southern Railway on a road 

that could easily be put in excellent condition for trucking.

LINCOLNTON, LINCOLN COUNTY.

Mine of the United States Tin Co. At the old Piedmont tin mine, 

2£ miles southeast of Lincolnton, the dikes in which the cassiterite 

occurs are fairly well kaolinized. The dikes occur 29 in a belt that 

strikes N. 20° E. and dips 80° NW.

The dike rock is a coarse-grained pegmatite that is composed 

mainly of quartz, several feldspars, muscovite, a colorless, somewhat 

brittle mica that may be margarite, and grains of cassiterite. Between the components are films of iron hydroxides that produce an 

orange-red stain. All the dike material is more or less kaolinized, 

and together with the kaolin there has been formed a reddish-yellow 

sandy product in which there are numerous plates of colorless mica, 

grains of quartz, and crystals of cassiterite. Where the original ma20 Graton, L. C., Reconnaissance of some gold and tin deposits of the southern Appalachians : U. S. Geol. Survey Bull. 293, pp. 42, 51, 1906.
68 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

terial was nearly pure feldspar the kaolin consists of kaolinite, small 

scales of mica, a very little quartz sand, and a few crystals of cassiterite.

The decomposed pegmatite is washed to obtain the tin ore. It is 

possible that it might prove profitable to save the washings and 

separate the kaolin.

KAOLINS FROM SCHISTOSE ROCKS (PARTLY PEGMATITES).

As these schists may be sheared igneous rocks of feldspathic character and in places are cut by pegmatite dikes of variable size, the 

kaolins derived from them are placed in a separate group. Moreover, 

they are placed closer to other kaolins which are wholly derived from 

pegmatite.

Only a few deposits of the white powdery kaolin believed to be derived from schistose rocks have been examined by the writer. Samples 

of others which were not visited were furnished by the owners of the 

property on which the deposits occur. The deposit near Troy was 

not visited, nor were any samples from it seen, but from the descriptions of it given by Bies there is no doubt that it is like some of the 

deposits that are mentioned below. Consequently Ries's description 

is abstracted, in the belief that it furnishes an idea of the character 

of the material in these other deposits.

TROY, MONTGOMERY COUNTY.

A deposit 4 miles west of Troy is mentioned by Ries.30 No account 

of the occurrence of the material is given, but from the description 

of its character it seems to be similar to that of the Candor and Eames 

deposits. Ries obtained two samples, one of them gray and the other 

white. The darker sample yielded 40 per cent of kaolin on washing. 

Both white and dark samples, when washed, burned to a buff color, 

and neither was suitable for the manufacture of white ware. As the 

characters of the Eames and Overton deposits are probably the same 

as those of the Troy deposits, a rather full abstract of Ries's account 

is given below.

The dark kaolin that was made into a workable paste with water 

shrank 3 per cent in drying and an additional 10 per cent in burning; 

The average tensile strength of the air-dried briquets was 9 pounds to 

the square inch. Incipient fusion took place at 2,100° F., vitrification 

at 2,300°, and viscosity at 2,500°.

The white kaolin shrank 3 per cent in drying and 9 per cent in 

burning. Air-dried briquets showed an average tensile strength of 

10 pounds to the square inch. The behavior in the fire was the 

same as for the dark variety.

Analyses of the kaolins yielded the following results:

80 Ries, H., Clay deposits and clay industry in North Carolina: North Carolina Geol. 

Survey'Bull. ]3, p. 64, 1897.
KAOLINS (WHITE RESIDUAL CLAYS). 69 

Analyses of crude kaolins from Troy, N. C.

Silica (Si02 ).. .......................................................................

Alumina ( AljOs) ....................................................................

Ferric oxide ( FejOa) .................. %. .............................................

Lime(CaO).................................................. . Magnesia (MgO) ......................................... i ..........................

Alkalies (NaaO+KjO). .............................................................

"Water (H2O above 100° C.) .........................................................

Moisture (HS 0 below 100* C.). ......................................................

1

63.10

23.33

2.97

.15

.09

1.90

7.C5

.75

99.94

2

86.03

6.46

2.14

.17

.04

1.00

2.90

.53

99.27

1. White kaolin.

2. Dark kaolin.

MOUNT GILEAD, MONTGOMERY COUNTY.

Property of P. M. Eames. An exploration on the property of 

P. M. Eames is 5 miles northwest of Mount Gilead, to the left of 

Lowders Ferry road. Very little is known about the deposit. Mr. 

Eames judges by the distribution of the outcrops that the clay covers 

about 700 acres. Only a shallow opening 2 feet deep has been mado 

in it, and from this opening a sample was taken.

The sample looks very much like that from the lotla mine at 

Candor. It is a very fine gritty flourlike material of a very pale 

grayish-white color. When mixed with water it becomes buff-gray 

and exhibits almost no tendency to cohere. After washing carefully in a test tube a fine-grained pale-buff residue* is left, which 

apparently consists entirely of quartz grains.

The crude material is made up mainly of small quartz grains that 

have diameters between 0.02 and 0.04 millimeter. In addition, there 

are a few particles of rutile, hydromica, and stained feldspar and a 

very few tiny plates of kaolinite. The quartz is in little sharpedged splinters, in subangular grains, in very irregular-shaped particles, and in a very few rounded grains. Evidently the material has 

not been carried far from its source. It may be a residual mass, 

like that at the lola mine,' from which the kaolinite has been removed, perhaps by running water.

In its present condition the material represented by the sample 

is not a commercial source of kaolin.

OVERTON, MONTGOMERY COUNTY.

Property of A. J. Overton. The Overton deposit is at the old 

lola gold mine, which is 2£ miles west of Candor and 8 miles east 

of Troy in Montgomery County. At this mine mineralized quartz 

veins are associated with a slaty rock which Hafer 31 believes may 

be a sheared andesite. The kaolin is reported by Mr. A. J. Overton, 

the owner of the land, to occur over 10 acres under an overburden

31 Min.' World, vol. 28, p. 332, 1908.
70 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

of about 8 feet of sand and gravel. The mine shaft that has penetrated it is 60 feet deep, and there are drifts 100 feet long at its 

bottom.

The sample sent is a loose, very light pinkish gray gritty flourlike mixture of very fine quartz and kaolin. The few lumps in it 

are distinctly schistose, as though the original material from which 

the clay was derived was a fine-grained schistose or slaty rock, as for 

instance a sheared felsite. When mixed with water it forms a distinctly cream-colored paste, and the coarse gritty residue left after 

washing the crude material is flesh-colored, and it contains comparatively large iron-stained grains.

Under the microscope the principal constituents visible are rough 

quartz grains of all sizes from the most minute to those 0.2 millimeter in length, though perhaps the greatest number have diameters 

between 0.03 and 0.05 millimeters. Besides these there are a few 

white opaque grains with straight edges that may be altered grains 

of feldspar and a fair quantity of small particles of "kaolinite of 

about the size of the smallest particles of quartz. There are a few 

shreds of kaolinite 0.06 millimeter long, but most particles are less 

than 0.004 millimeter across.

The washed samples of the three kaolins from Montgomery County 

contain a great deal of fine quartz, in which respect they differ 

markedly from the kaolins that are known to have originated by 

the decomposition of pegmatites. All of them were probably derived 

from fine-grained rocks like the rock associated with the kaolin at the 

Hill property at Abbeville, S. C., in the shaft west of the road. 

(See p. 80.)

CATAWBA, CATAWBA COUNTY.

Property of E. A. Ervw. In Catawba County, on the State Central Highway, 3 miles east of Catawba village, on the property of 

E. A. Ervin, is a deposit of white powdery clay that has been used 

locally for whitewash. The clay appears for about 200 yards down 

the bottom of a- stream. Upstream it is reported to be about 30 feet 

wide. At the lower end the color gradually changes to blue and 

dark gray.

The sample taken from the upstream end of the deposit is very 

much like the material from Mr. Valentine's deposit in Henderson 

County. It is a very fine grained gritty powder composed of spicules 

and irregular sharp-edged particles of quartz, few of them over 0.02 

millimeter in their largest diameter, and numerous small flakes and 

fragments of aggregates of flakes of kaolinite. There are a few 

grains of quartz that measure 0.1 millimeter, but they are extremely 

rare. If the kaolin is sedimentary its components have traveled a 

very short distance, as many of the quartz spicules are extremely 

slender.
KAOLINS (WHITE RESIDUAL CLAYS). 71

STATESVIIXE, IKEDELL COUNTY.

Property of Gashion & Furchess. An apparently large deposit of 

kaolin occurs along the Charlotte branch of the Southern Kailway 

1 mile south of Statesville, on land belonging to Messrs. J. T. Cashion 

and H. V. Furchess. The property is undeveloped, but cuts on the 

railway and on the highway one-fourth of a mile west of the railroad 

expose kaolin.

On the east side of the right of way of the railroad a section of 

about 160 feet is exposed and between this section and the track are 

a couple of shallow pits. The section shows alternating schists and 

kaolin. At its north end a width of 20 feet of kaolin is shown, followed to the south by 20 feet of quartz, 110 feet of kaolin, and finally 

schists. ('See fig. 12.) The schists consist of alternating mica schists 

and quartz-feldspar schists full of garnets. These schists are interlayered with rocks that appear to be sheared pegmatites. The feldspar in all the schists is kaolinized and one layer between slightly

Kaolin Schist

50 Feet

FIGURE 12. Relations of kaolin in deposit owned by Cashion 

& Fuvchess, Statesville, N. C.

decomposed mica schists consists of a well-defined kaolin. The strike 

of the series of schists is N. 10° W. and its dip is 75° E. East of the 

railroad schists outcrop here and there, but in a well dug 500 yards 

east of the rails clay was struck at about 12 feet.

The clay exposed in the cut north of the schists is very sandy. It 

contains in addition to the sand tiny flakes of dark and light mica, 

little masses of soft black material that may be a manganese oxide, 

and little yellow spots that may represent decomposed garnets. The 

kaolin has an ill-defined structure that is parallel to the structure 

of the schists to the south and is crossed by vertical, or nearly vertical, veins of quartz. Most of these veins are narrow, but at the 

north end of the cut one of them is 20 feet wide. Northward in the 

cut the whole rock mass appears to disintegrate gradually, changing 

to layers of red-brown clay and white clay. The white clay becomes more .abundant toward the north as though the clay-producing layer became thicker. Pits near the track show a cleaner and 

whiter clay than that in the cut, and from one of these pits the 

sample was taken. The clay probably represents a thick layer in 

the schist series, but whether this layer was composed of a f eldspathic 

schist or of a sheared pegmatite running parallel to the foliation of 

the schists was not determined. The thickness of the kaolin is
.72 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

also unknown. As already stated, kaolin exists in a road cut about 

one-fourth of a mile west of the railroad. Near this place a well 

was dug that passed into white clay at a depth of 6 feet and continued in it for 55 feet. Between the well and the railroad there 

are no exposures and no explorations, so that it -is impossible to determine whether a single layer is continuous through this distance 

or whether there are several layers separated by schists that are 

not kaolinized. The distribution of the .kaolin is rather widespread. 

If its origin is as suggested it must occur on the surface in belts 

that strike nearly north.

The kaolin from the pit at the railroad is white and pulverulent. 

It contains comparatively few fragments of quartz, a good deal 

of sand, very small masses of soft brown clay, a few flakes of mica, 

and a few specks of a soft black substance. Under the microscope 

most of the quartz is seen to be in sharp-edged flakes and splinters. 

Some grains are rounded. Plates of hydromica and sharp-edged 

grains of partly kaolinized feldspar are common, as are also small 

plates and flakes of kaolinite. There are also a few black specks of 

opaque mineral and tiny reddish-brown plates that may be limonite. 

The material, as a whole, resembles closely the Overton kaolin.

BOSTICKS MILLS, RICHMOND COUNTY.

Property of R. L. Steele. The Steele explorations cover an area 

the center of which is 2J. miles northwest of Ellerbe on the Norfolk 

Southern Railway near Bosticks Mills. The property on which the 

clay occurs consists of 38^ acres owned in fee by Robert L. Steele, sr., 

who owns also the mineral rights in 230 additional acres. When 

worked a few years ago it was operated under the name of the 

Steele Kaolin Works, with headquarters at Rockingham. In 1897 

Ries 32 referred to openings in kaolin on the property of Mr. Steele, 

but none of these openings can be identified with those seen by 

the writer in 1918. However, as the clay evidently occurs over a 

fairly wide area, the conclusions of Ries as to the quality of the 

kaolins seen by him would probably apply nearly as well to those 

taken from the openings examined in 1918.

Ries states that the clay appears for a distance of 50 feet in a roadside ditch a mile south of Bostick post office and again on the opposite side of the road at the base of a hill. Between the two localities 

there is a red clay which is the product of the decomposition of a 

schist. Test pits sunk east of the road disclose a fine-grained clay, 

which contains comparatively few angular fragments and scattered 

stains of iron. Another series of pits a mile farther west, across a 

shallow valley, uncovers another deposit of whiter material. In no

32 Ries, H., op. cit., p. 65, 1897.
KAOLINS (WHITE RESIDUAL CLAYS). 73

pit was the overburden more than 1£ feet thick or the kaolin less 

than 9 feet thick.

The clay from the eastern pits (analysis 1) was a fine-grained 

kaolin with a little coarse grit. It slakes slowly but completely to a 

fine-grained mass. A workable paste shrank 4 per cent on drying and 

9 per cent in burning. -Air-dried briquets showed an average tensile 

strength of 10 pounds to the square inch. Incipient fusion began at 

2,250° F., vitrification at 2,500°, and viscosity at 2,700°. The clay 

burned to a dense body that had a pale-yellow tint. A sample from 

another pit (analysis 2) underwent slightly less shrinkage. The average tensile strength of its briquets was 13 pounds, and incipient 

fusion began at 2,300° F. In other respects it was like the first sample. The kaolin from the western pits (analysis 3) was a somewhat 

porous, fine-grained white clay with comparatively little grit. In 

most respects it was nearly like the material from the eastern pits.

Analyses of this material gave the following results:

Analyses of samples of crude kaolin from Bosticks Mills, Richmond County, N. C..

Silica (SiO-j) ...................................................

Alumina (A1 2 08 ) ...............................................

Ferric oxide (FeaOs) ...........................................

Lime (CaO). ...................................................

Alkalies (KjO+NajO).... .....................................

Water (H2 0 above 100°C.) .....................................

Moisture (H2O below 100°C.). . .................................

1

70.63

21.81

1.49

.20

.29

1.45

4.04

.08

99.99

2

68.15

19.99

1.86

.13

.16

2.85

4.70

.17

98.01

3

73.70

16.03

1.57

.38

.47

1.90

4.33

98.38

4

71.12

19.61

2.18

.17

.08

2.^8

4.33

99.97

1. 2. Clay from the eastern pits.

2. 4. Clay from the western pits.

Samples Nos. 1 and 3 were washed. The first sample gave 40 per 

cent of settlings and the second 35 per cent. The washed sample 

No. 1 had the same properties as the crude sample No. 4. Washed 

sample No. 3 was pure white, but it burned to a body that had a faint 

yellowish tint. In all respects the washed material acted like the 

crude sample, except that its briquets had an average tensile strength 

of only 8 pounds to the square inch. The following table shows the 

calculated mineral composition of each of the four samples analyzed:

Mineral composition of samples of kaolin from Bosticks Mills, Richmond Counly,

N. C.

1

47.14

16.13

30. 73

2.41

2

49.30

9.20

41.50

2.52

3

36.05

UA. UO

2.43

4

54.30

/ 1.82

\ 43.85
74 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The openings that may be seen now are widely separated. One 

on a crossroad running east from the main road north from Ellerbe 

is on a dense, gray, massive, sticky clay that contains lines of limonite 

nodules, most of which are hollow or partly filled with red clay. 

Other nodules in the clay are concretions of quartz fragments, sand 

grains, and flakes of mica cemented into elongate bodies about 1£ 

inches long and half as thick. As the clay where exposed has a 

horizontal upper surface it resembles very closely a sedimentary 

deposit. Close examination of the walls of the pit, however, reveals 

the presence of a system of cross joints, such as appear in a sheared 

rock, and a number of tiny quartz veins that intersect the clay in 

nearly vertical planes. The exposure is too small to furnish much 

evidence of the origin of the clay, but the vertical quartz veins and 

the presence on the main road of rocks that might well be the 

source of such a clay indicate that the gray clay is a residual deposit, resulting from an alteration of a sheared clay shale or slate 

or perhaps a sheared volcanic rock. The hollow nodules of limonite 

may have been formed during the alteration of the slate to clay and 

the sandy concretions may originally have been little lenses of sand 

in the otherwise argillaceous rock. Only about 20 tons of the clay 

have been sold. The crude material was washed in a homemade 

washer and sold as a filler for cheap cotton goods. The unwashed 

clay burns gray.

On the main road, near Ellerbe, chocolate and ocher colored clays 

are exposed in the ditches. They are extremely fine grained and 

very slightly gritty and massive, but when broken apart many of 

the lumps show distinct schistosity. Mr. Steele says that a little 

of the yellower variety has been burned and sold as ocher. The 

clays of both colors are associated with jointed rocks that may be 

shales or slates, as they readily fall apart into lozenge-shaped fragments, some of which consist partly of yellow clay. The freshest 

rock that was seen in place is presumably a pale-gray clay slate, 

almost the same color as the gray clay ^t the pit. Although distinctly slaty, the clay is nevertheless very soft as if very compact.

The country about Ellerbe is underlain by slates or sheared volcanic rocks which differ in composition, and the different colored 

clays on the road are the result of their decomposition. The gray 

clay is possibly of a similar origin. It may have been derived from 

a less ferruginous rock than those that gave rise to the colored 

clays, or during its formation the iron compounds may have been 

leached out, in part forming the concretions found scattered through 

i't. These concretions, when treated with hydrochloric acid, leave 

residues of white kaolin of the same shapes as the original nodules, 

indicating that the nodules were not present in the original rock? 

but were secreted after or during the production of the kaolin.
KAOLINS (WHITE RESIDUAL CLAYS). 75

West of the main road, about 1£ miles west of the pit in the gray 

clay, there is another opening on a hill covered with quartz boulders. 

No rock was seen in place. The pit has partly caved, but in some 

places around its sides a very white compact clay occurs, which, 

when it dries, breaks down into a very fine white powder that is 

quite gritty. When mixed with water it becomes very pale grayish 

white. The material, when examined microscopically, is seen to 

consist mainly of small splinters and tiny dustlike particles of 

quartz of 0.003 to 0.02 millimeter in diameter and small flakes of 

kaolin about 0.004 millimeter in diameter. No other constituents 

were noted, except here and there a shred of decomposed mica.

From the nature of the kaolin, its similarity in physical characters (except color) to the yellow and chocolate-colored clays in its 

neighborhood, and its likeness to the Overton and Eames clays 

(pp. 69-70) it is inferred that it is residual and that it was formed 

from some rock that occupied a fairly broad area and not from a 

pegmatite dike. At Candor and Troy the original rock was probably a feldspathic volcanic rock. At Ellerbe there may have been a 

series of slightly different volcanic rocks or of alternating slates and 

volcanic rocks.

Mr. Steele declares that borings about 30 or 40 feet apart over 

25 acres penetrated from a thin film to 35 feet of sand and clay 

overburden and found underlying white and colored clays. Some 

borings found only colored clay, others only white clay, and others 

mixtures of the two. The holes were not located in order to determine the areal distribution of either kind, and consequently no estimate can be made of the quantity of the white clay available.

Neither one of the pits is now being operated. . The eastern pit 

was worked in 1904, the clay being used mainly for cotton and paper 

filling. Only a small quantity was marketed, perhaps 150 or 200 

tons. It was hauled by team 14^ miles to Rockingham. It could now 

be hauled by truck 4 miles to Norman and shipped by the Norfolk 

Southern Railroad.

KAOLIN RESERVES OF NORTH CAROLINA.

An estimate of the quantity of available kaolin in the known 

deposits of Mitchell, Yancey, and neighboring counties is of little 

value. Undoubtedly there is a large quantity of kaolin in the 

ground. Its distribution, however, is unknown. The slight development of most of the deposits does not indicate how much of 

the material can be mined with profit, even under the most favorable 

conditions, for the dimensions of the. individual deposits are not 

known. The deposits that are now being exploited and those that 

have been explored by boring are estimated to contain more than
76 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

450,000 tons of commercial kaolin. This is a much smaller amount 

than that stated by the owners of some of the kaolin properties in 

this area, but in their estimates they assume that all the kaolin in 

the ground can be removed, which is impossible.

The aggregate quantity of kaolin in all the deposits in North 

Carolina is very great. Unfortunately, however, the expense of 

preparing the material for market precludes the working of many of 

them because of their small size. So far as now known only a few 

of them contain sufficient crude material to warrant the construction of the washing plants necessary to fit this material for market. 

The data now at hand indicate that there is enough material to furnish about 625,000 tons of refined product. The annual output of 

the State is 16,000 tons; consequently the supply is probably sufficient 

to last 39 years at the present rate of production. But because of 

lack of labor the production is less than the capacity of the plants. 

With plenty of labor the output may be increased 50 per cent. 

Moreover, as the methods of preparing the kaolin for market are 

improved there will unquestionably be an increase in the demand for 

the refined product and an enlargement of the plants to take care of 

the increased demand, and the life of the reserve will be correspondingly shortened.

A glance at the map (PL I), however, will show that the deposits 

now known center around a few points, notably Dillsboro, Sprucepine, and Micaville. The most attractive deposits may occur in these 

areas, but more probably, however, the discovery of a few good 

deposits near these centers has encouraged the search for others in 

the same neighborhoods, and this may be the explanation of their 

peculiar distribution. It is known that pegmatite dikes are scattered rather uniformly through the mountain district, and the 

distribution of the mica openings corroborates this view. There is 

no reason to believe that the kaolinized dikes are less widely distributed than those that are being worked for mica. But kaolin will 

not bear as high costs of transportation as mica, consequently the 

profitable deposits of kaolin must be close to the railroad, whereas 

deposits of mica may be more distant. Large areas in the mountain 

districts have not been explored for kaolin, because of the difficulty 

of getting the product to market. It is probable that these areas 

contain deposits, which, except for the cost of transportation to the 

railroad, would furnish as profitable sources of kaolin as some of 

those now being exploited. With the extension of the system of 

hard roads into remote mountain regions the use of trucks will be 

more feasible and the cost of transporting the refined kaolin will 

decrease. Exploration of the mountains will then become more 

attractive, and unquestionably, as a consequence, new sources of 

kaolin will be discovered. , It is impossible to make any estimate of
KAOLINS (WHITE RESIDUAL CLAYS). 77

the probable amount of material these new sources will contribute 

to the State's output, but there will undoubtedly be enough kaolin 

in deposits now unknown to lengthen the life of the kaolin industry 

several times beyond.that indicated by the size of the reserve now 

known.

PROSPECTING FOR KAOLIN.

All the deposits of kaolin now being operated in North Carolina 

are on the slopes of hills in the mountain district, but unquestionably 

good deposits exist also in less exposed situations, where they are 

not so easily detected because usually covered by debris from the 

slopes. On slopes the debris produced by weathering is removed 

almost as rapidly as it is formed, and the white kaolin is exposed. 

At the bases of slopes the narrow kaolin masses are covered by creep 

or wash from the overhanging hills and many of them are nearly 

completely obscured.

In some places on flats or low slopes where the kaolin can not be 

seen its presenos beneath the soil may be inferred from the large 

fragments or boulders of quartz on the surface. The boulders 

result from the decomposition of coarse pegmatites, as there are no 

other rocks in this portion of the State that yield quartz boulders 

upon weathering. Consequently the presence of quartz boulders 

suggests decomposed pegmatites, and as the decomposition of pegmatites commonly produces kaolin, it follows that the presence of the 

boulders on the surface may indicate the presence of kaolin beneath 

the surface.

After the existence of kaolin has been determined it is desirable 

to ascertain its extent before undertaking any expensive development 

to prove its value. This is done with an auger welded to a section 

of steel pipe long enough to enable the operator to penetrate the deposit at least 30 feet, and the usual precautions should be taken to 

see that the sample does not become contaminated with material 

scraped from the side of the bore hole by the auger. Borings should 

be made at intervals of about 15 feet in a series of lines at right 

angles to one another until the area tested is large enough to establish definitely tba width of the deposit and its general direction. 

Care should be taken to make sure that its actual limits have been 

reached before abandoning the cross boring. It must be remembered 

that quartz horses are common in many of the deposits and that 

they will stop the auger as effectually as wall rock. Before abandoning the cross boring a sufficient number of holes should be sunk to 

rock to establish the fact that the limit of the deposit has been reached 

in that direction. After proving the width of the dike holes should 

be bored along its length through a distance that will leave no doubt 

as to its magnitude. These holes should be closely spaced along the
78 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

borders of the deposit but may be more widely spaced within its 

borders.

After having determined that the size of the deposit is sufficient 

to warrant working, provided the quality of the kaolin is satisfactory, it is necessary to obtain as nearly as possible an average sample 

for study. Such a sample is best obtained by driving a tunnel from 

the face of a slope into the deposit and crosscutting, care being taken 

to grade the tunnel so that it will readily drain. Samples should be 

taken from the entire length of the walls of both tunnel and crosscut, 

omitting only those portions occupied by horses so large that they 

would have to be left during mining. With this exception, all horses 

should be sampled as well as the pure kaolin, so that the sample 

may represent a fairly complete section of the walls throughout 

the extent of the -mass that would be removed in mining. The 

sample thus obtained should be mixed with samples from horizontal 

borings at definite intervals into the walls on both sides of the tunnel 

and crosscut and from vertical borings into the roof and floor. The 

samples should be preserved in bags and with each bag there should 

go a record explaining exactly how the sample was obtained and 

from what part of the deposit it was taken. This is necessary, as 

different portions of a deposit may yield materials that have different 

properties, and the probable proportions in which these materials 

occur should be determined.

After the several samples have been collected one or more general 

samples should be made by mixing the individual samples in their 

proper proportions, and these general samples should be subjected to 

the tests that have been prescribed for determining the value of a 

kaolin for the purposes for which kaolins are used. A chemical 

analysis is not necessary, but a burning test is essential.

In estimating the volume or the thickness of the deposit, or the 

waste material in streaks of impurities such as quartz veins, allowance should be made for the slant or dip of the pegmatite dikes, 

which usually increases the apparent thickness of a quartz vein, for 

instance, to an amount greater than its real thickness.

USES OF KAOLINS OF NORTH CAROLINA.

The kaolins of North Carolina are used in making china, semiporcelain, and porcelain, mosaic and other tile, and in the manufacture 

of spark plugs.

Their principal use is in the bodies used for different grades of 

china and other white ware. They constitute from 2£ to 15 per cent 

of the mixture, the other ingredients usually being English or domestic ball clay, English china clay, Florida clay, and often clays 

from other domestic sources. Some potters describe the kaolins of
KAOLINS (WHITE RESIDUAL CLAYS). 79

North Carolina as very satisfactory when not introduced into the body 

in large quantity. Others declare that their use is objectionable in the 

manufacture of fine ware, but that if better cleaned they would be the 

equal of any English clay. Some of the product contains too much 

grit and some of it is contaminated with particles of yellow material, 

which appear as tiny black specks in the finished ware. In a few 

potteries it is apparently slowly replacing imported clay; in others 

its use is gradually being abandoned. One of the largest users reports 

that in his practice he has found it to burn to a greenish body marred 

by black dots, and that as the demand for more perfect ware is pressing he is compelled to diminish the quantity he has been using and is 

substituting for it English china clay. At one pottery, however, satisfactory ware is being produced from a mixture containing only 

American clays. In this mixture North Carolina kaolin constitutes 

about 20 per cent of the mass.

It is evident that although in the practice of some potters the kaolin 

from this State gives satisfactory results, it is generally not entirely 

satisfactory and consequently is used sparingly. As the troubles have 

been chiefly with plasticity and shrinkage it may be that with a change 

in the formulas at some of the potteries the quantity of the kaolin 

from North Carolina that could be introduced inp the mixture might 

be considerably increased. Nevertheless, a more certain means of extending its use would be to change the method of washing the crude 

clay sufficiently to assure the removal of all of the grit and other ingredients that are so objectionable to the potters.

An important recent uss of the kaolin from North Carolina, though 

one that does not yet require large quantities, is in the manufacture 

of glass-melting pots. So far as known, commercial tests of the 

suitability of North Carolina kaolins to this purpose have not proceeded far enough to yield definite results. However, the Bureau 

of Standards has shown that a mixture containing 24 per cent of 

kaolin from North Carolina, together with white clays from Georgia 

and Florida and ball clays from Tennessee and Kentucky, worked 

up with an equal quantity of grog will produce a glass pot of satisfactory quality for ordinary purposes.33

SOUTH CAROLINA.

By W. S. BAYLEY.

ABBEVILLE COUNTY.

The only high-grade residual clays that occur in the area west of 

the fall line in South Carolina are near Abbeville, Abbeville County, 

and belong to the Abbeville-York series of Sloan.

81 Bleininger, A. V., Special pots for the melting of optical glass: Am. Ceramic Soc. 

Jour., vol. 1, No..l, p. 15, 1918. See also Wright, J. W., and Puller, D. H., Note on the 

casting of porcelain glass pots: Am. Ceramic Soc. Jour.,,vol. 2, p. 659, 1919.
80 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Kaolin occurs on the property of Messrs. J. A. and W. E. Hill, 

2£ miles south of Abbeville, at the Vienna Crossroads, but is poorly 

exposed by very little development. Mr. J. A. Hill reports that 

borings over 75 acres at 60-foot intervals have outlined a mass of clay 

50 feet wide and 1 mile long. The kaolin is best seen on the west side 

of a cut in the road where it crosses over the top of a grade. Its 

relation to the neighboring rocks is shown in the accompanying 

sketch (fig. 13). The kaolin is in a dike 50 feet wide that strikes 

nearly northwest and dips 75° SW. Both above and below it is a 

coarse dark granite that has been almost completely decomposed so 

that it is now a mass of quartz particles in mottled clay with the appearance and structure of an aggregate of feldspar and some ferromagnesian mineral. The footwall granite near its contact with the 

kaolin is cut by tiny veinlets of kaolin that run nearly parallel to 

the contact, with the dike. South of the upper granite and apparently overlying it is a breccia-like mass of clay, rock, and rounded 

quartz fragments that may represent a very coarse granite. The

 ^^^1^. >>V'X,V K30lin AV; Granite 

^^^^'»'/ ^v /^£AV/

O____ ISO Feet

FIGURE 13. Section in west side of cut in road 2£ miles 

south of Abbeville, S. C. a, Kaolin deposit.

whole is capped by an overburden of 4 to 10 feet of red clay. A 

shaft was sunk in the kaolin (&, fig. 13) to a depth of 36 feet without reaching rock. Here the kaolin is in all probability a decomposed pegmatite like the kaolins that are so common in the mountain regions of western North Carolina. It consists mainly of

kaolinite, quartz, and partly kaolinized feldspar, with a very little 

decomposed muacovite and a few small flakes of brown mica. Scattered through it are little clumps of reddish gritty clay that are apparently completely decomposed garnet. When mixed with water 

the mass turns to a very dark cream-color or a distinct reddish yellow. 

The quartz is in very irregular sharp-edged grains of all sizes from 

0.2 millimeter in diameter down to dust. Many of the grains are 

cloudy and some are stained brown. The feldspar, which is white 

and opaque, is in more or less rounded grains, many of them colored 

reddish brown. Other brown masses may be iron-stained kaolin. 

The mica as a rule is also stained, and most of it is altered. The 

kaolinite is in comparatively large plates, measuring from 0.012 to 

0.02 millimeter in diameter, and these are commonly grouped into 

rosettes and wormlike aggregates. Besides the plates there are very 

numerous small, dustlike grains like those that occur in all kaolins.
KAOLINS (WHITE RESIDUAL CLAYS). 81

Aii analysis made by Dr. K. N. Brackett, of Clemson College, 

yielded the following results:

Analysis of kaolin from Albeville, S. C.

Silica (Si02 ) _____________________-__ - 56.00 

Alumina (A12O3 )___________________________ 28. 63 

Ferric oxide (Fe203 )__-____________________ 3.97 

Lime (CaO)_____________________________ 1. 20 

Magnesia (MgO)_________________________'_ .21 

Soda (Na20)___________________________ 1.34 

Potash (K2 0) ____________________________ 1. 02 

Manganous oxide (MnO) _-_ _ _ __ Trace. 

Titanic oxide (Ti02 )____________________ _ Trace. 

Water (H2 0)____________________________ 8.00

100. 37

This composition corresponds to 10.14 per cent quartz, 29.46 per 

cent feldspar, and* 60.77 per cent clay substance.

This clay burns to a dense cream-colored biscuit. 

"About 500 feet west of the road is another shaft where the conditions are somewhat different from those noted on the road. The 

shaft itself has collapsed and can not be entered, but on the dump 

lies a considerable quantity of coarse kaolin that looks very much 

like the crude material from North Carolina. It contains coarse 

quartz and a little white mica. Large boulders of a thoroughly 

kaolinized felsitic rock, probably a rhyolite, are scattered in the 

vicinity, and some of these are said to have been taken from the shaft. 

More common than these boulders, however, are great boulders of a 

coarse dark granite, which, of course, is much decomposed, but which 

has not yielded any great quantity of kaolin. The shaft is possibly 

in a decomposed pegmatite that was intruded in the felsite and granite, but more probably it was sunk in a portion of the felsite that was 

thoroughly altered. Whatever the original source of the kaolin at 

this place, unquestionably, both here and on the road, it is residual. 

Dr. Brackett also analyzed a sample of this clay and obtained the 

following results:

Analysis of residual clay from the vicinity of A^ev-ille, S. C. 

Silica (SiO_)_ - _________ 73.55 

Alumina (A1203 ) ______ 13.82 

Ferric oxide (Fe2 03 ) ___________ 2.98 

Lime (CaO) __________^_ 1. 80

Magnesia (MgO)_____ i _____ ____________ . 23

Soda (Na,0) ___ _____________ 3.28

Potash (KJ,0) - - *.__._____ 2.'51 

Manganous oxide (MiiO) , ________ Trace. 

Titanic oxide (T;iOa) __,__ Trace. 

Water (H_O) ________ 1.85

100. 07 

77412 22 7
82 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

This composition corresponds to 25.18 per cent quartz, 63.02 per 

cent feldspar, and 11.87 per cent clay substance.

GEORGIA.

Pegmatite dikes are known within the Piedmont region of Georgia, 

but no records of any valuable deposits of kaolin there have been 

found.

Veatch 34 in his report on the clays of Georgia has noted one 

deposit 4 miles northeast of Union Point, Greene County, from which 

a small quantity of kaolin was mined. It was rather siliceous, 

burned white at cone 5, faint cream at cone 13, and fused at cone 30.

ALABAMA.

Kaolins derived from pegmatites are reported from Milner, Pinetucky, and Micaville, Randolph County, and Stone Hill, Cleburne 

County, as well as from a few other localities, but they are undeveloped.

KAOLIN FROM CAMBBIAN SCHISTS IN PENNSYLVANIA.

Kaolins derived from siliceous schists are associated with the 

Cambrian formations of southeastern Pennsylvania. Although they 

occur at several localities, they have not been traced continuously 

from point to point, and as their mineral character differs appreciably, it is not certain that they are all formed from the same division of the Cambrian system of rocks.

The three localities from which these kaolins are known are Glen 

Loch, Delaware County; Mount Holly Springs, Cumberland County; 

and Narvon, Lancaster County.

The first two localities yield a residual clay that is practically 

white, but the clay from the last locality is not white, except in one 

opening.

GLEN LOOH, DELAWARE COUNTY.

Hopkins 35 in his report refers to a kaolin mine and washer 1^ 

miles north of Glen Loch station on the north side of Little Chester 

Valley. The mine is near the contact of Ordovician limestone and 

Cambrian sandstone. The sandstone outcrops a short distance north 

of the mine and the limestone a short distance south, but neither

84 Veatch, Otto, Clay deposits of Georgia: Georgia Geol. Survey Bull. 18, p. 256, 1909. 

35 Hopkins, T. C., Clays of southeastern Pennsylvania (in part) : Pennsylvania State 

Coll. Ann. Eept. for 1898-99, Appendix, p. 30, 1900.
KAOLINS (WHITE RESIDUAL CLAYS). 83

rock is in contact with the clay. Large masses of coarsely granular 

white quartz occur in and near the kaolin, and some of these contain 

wavellite. The kaolin deposit dips into the hill and thence runs 

under the iron ore which is north of it. Hopkins comments on the 

remarkable similarity of this clay to the South Mountain kaolins.

The writer has not seen this locality but has received a sample from 

it, which is a grayish-white sandy clay that appears to be free from 

mica. This sample indicates that the deposit bears a closer physical 

resemblance to the South Mountain deposits, which also carry wavellite and iron ore in places, than to the deposits derived from pegmatite which lie to the south.

The crude clay, when examined under the microscope, shows abundant grains of quartz, some grains of hydromica, and abundant 

grains of kaolinite, as well as a little rutile.

The clay has moderate plasticity. One sample, which was fired 

at cone 10, burned grayish white; its absorption was 18.7 per cent 

and its porosity 36 per cent. It is therefore not a very dense-burning clay. At cone 10 it was nearly steel hard. It would be necessary 

to wash the clay for market, and the percentage of washed product 

would not be very high.

SOUTH MOUNTAIN REGION, CUMBERLAND COUNTY.

General features of the deposits. The deposits in this region have 

been described in some detail by Hopkins 36 and Stose. 37 Since their 

reports were issued some deposits formerly operated have closed 

down, and others have been developed.

South Mountain, on whose flanks the white clays occur, extends 

from Potomac River, at Weverton, north and east to Susquehanna 

River south of Harrisburg. It is composed of several parallel 

ridges with steep-sided longitudinal valleys in between them. These 

ridges are composed chiefly of hard Cambrian sandstone, whereas 

the valleys, according to Stose, are underlain by shale. The sandstones iorm part of a great anticlinorium or arch, which has vertical 

or overturned dips on the northwest side. To the southeast of the 

sandstone, ridges lie volcanic rocks, which form the core of the 

fold, whereas to the northwest the Cumberland Valley is underlain 

by Cambrian and Ordovician limestones-. The area in which clay 

may occur is therefore rather well defined.

88 Hopkins, T. C., Pennsylvania State Coll. Ann. Kept, for 1899-1900, Appendix, 1901. 

87 Stose, G. W., White clays of South Mountain, Pa.: U. S. Geol. Survey Bull. 315, 

p. 322, 1907.
84 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The deposits of clay occur chiefly southeast and southwest of 

Mount Holly Springs (see fig. 14), but most of the pits have been 

opened in the valley of Mountain Creek.

All the clays are residual and have been derived from a siliceous 

schist; indeed specimens showing all stages in the transition from 

schist to clay can be found.

Hopkins states that the white clay has been derived from hydromica slates, " which occur intercalated in the Cambro-Ordovician 

limestones and in the Cambrian slates, sandstones, and quartzite."

No limestone was seen by the writer in association with the clay, 

but Stose states that some is found in one of the Philadelphia Clay 

Co.'s tunnels.

Two structural features seem to be constant in the Holly Springs 

region. First, that the clay bed is usually under a distinct topoMine X Prospect

FIGURE 14. Map showing clay mines in South Mountain district, Pa. 1, Holly Clay 

Corporation ; 2, Philadelphia Clay Co. ; 3, Sandusky Portland Cement Co. ; 4, Russell's 

tunnel ; 5, Fishel's prospect pits.

graphic bench on the mountain slope. Second, that in driving a 

tunnel into the mountain at different localities there is encountered 

first a colored plastic clay, which usually contains iron ore, then a 

white clay that differs in thickness in different localities, and lastly 

sandstone, which underlies the other beds stratigraphically.

The clay ground is commonly soft, wet, and treacherous, so that 

underground mining seems to have been the method preferred in 

several places, presumably because the operators though that an 

open cut would tend to slide so as to interfere with the work of 

excavation.

The clays are all fine grained and contain a high percentage of 

very fine silt, which is difficult to eliminate in washing. They burn 

to a very light cream color and have a somewhat high fire shrinkage.
KAOLINS (WHITE RESIDUAL CLAYS). ' 85

They have not thus far been used much for pottery manufacture, 

but their chief application has been as a filler for paper and in paints. 

All of them have to be washed to eliminate as much of the fine sand 

as possible.

 Property of the Cumberland Clay Co. The property of the Cumberland Clay Co. was in the eastern end of Mountain Creek Valley, 

east of Upper Mill. The deposit, which was quite extensive, had a 

steep dip. The property is no longer in operation.

Property of the Philadelphia Clay Co. The Philadelphia Clay 

Co. continues to be the largest producer in this region. Tlje mine 

is on the northwest side of Mountain Creek Valley about 2£ miles 

soutliAvest of Upper Mill. Its plant was described somewhat fully 

by Stose, but permission to publish any recent data regarding it is 

withheld at present. It may be said, however, that the deposit is 

mined by tunnels that penetrate the colored clay to the white material, which is then worked out as far as practicable from the one 

tunnel, after which a new one is driven.

The crude clay and the washed product, on examination under the 

microscope, gave the following results:

Crude clay: Sample, as a whole, medium-grained with dustlike 

specks. Quartz, abundant; hydromica, fairly common; kaolinite, 

abundant; rutile, numerous in very minute needles; tourmaline, a 

few grains. " 

Washed clay: Texture as a whole, fine. Quartz, fairly common; 

hydromica, common and much of it in flocculated grains; kaolinite, 

abundant; tourmaline and rutile, present in a few small grains.

The chief difference between the crude and washed clay appears to 

be in the finer size of the quartz grains, although the quantity of 

this material is somewhat less.

Property of the Sandusky Portland Cement Co. The Sandusky 

Portland Cement Co. has a mine about three-quarters of a mile 

southwest of the mine of the Philadelphia Clay Co. The clay does 

not outcrop. , The company has driven two tunnels, the upper one 

of which is closed. The lower tunnel is somewhat winding and 

about 800 feet long. It branches into several headings near the 

end. The first part of the tunnel is in the usual .colored clay. The 

product from this mine is used in the manufacture of Portland 

cement.

A sample of creamy-white, hard sandy, clay showing laminated 

structure, which was taken from the tunnel heading, was examined 

under the microscope. It was medium to fine grained, Quartz was 

very common, as was also the hydromica; kaolinite was abundant. 

Rutile also appeared to be common but was in very minute prisms.
86 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

A sample of the softer clay, like that being shipped from this 

locality, was also examined microscopically. This sample was medium to coarse grained and the quartz was fairly abundant. Hydromica, partly flocculated and partly in the form of tiny needles, was 

abundant, and kaolinite was more so. There were numerous tiny 

grains of rutile and a few grains of both tourmaline and chlorite.

The clay is fairly plastic, though it contains much fine quartz.

A sample of it fired at 1,150° C. had 6.4 per cent absorption and 

15.9 per cent porosity, while another fired at 1,300° C. had 0.1 per 

cent absorption and 1.2 per cent porosity. The clay burned buff at 

the lower temperature as well as steel hard, but at the higher temperature it was gray.

Henry Clay mine. The Henry Clay mine is near Henry Clay, on 

the southeast side of the valley. It was formerly worked by tunnel 

and shafts to supply the Mount Holly Brick & Clay Co., but is no 

longer in operation.

Property of the Holly Clay Corporation. The Holly Clay Corporation has recently begun operations on the northwest side of South 

Mountain and about 2 miles east of Mount Holly Springs. Some 

years ago clay was dug here for brick manufacture. The deposit 

underlies the bench on the north slope of the mountain, and the pit 

is about 2,000 feet south of the Philadelphia & Reading Railway 

tracks. Unlike the other companies, this one is working the deposit 

as an open pit (PL IV, A), digging the clay with a steam shovel. 

At the time of our visit the pit showed 15 feet of overburden and 

12 to 15 feet of clay.

Test holes bored up the sloping surface of the bench for a distance of about 600 feet show white clay covered by 10 to 26 feet of 

overburden, and white sand usually immediately over the clay.

The clay in the pit is light-grayish white, though in places it is 

mottled with limonite. Here and there occur streaks of clean sand 

and also sandy clay. Angular lumps of quartzite are scattered 

through the clay, and these are in some places in bands, as though 

they represented thin beds of quartzite in the schist from which the 

clay is derived.

The method of treatment here is unique in the clay industry, because of the types of purifying apparatus used. At the pit the clay 

is dumped into a log washer, from which it passes to a short trough, 

where the stones are separated. It then goes to a Dorr classifier, 

whose action is similar to a blunger. The clay and water are then 

taken up a pipe line to the washing plant, where it passes successively through a Dorr hydroseparator, 50-foot sections of trough, 

Dorr thickener, filter press, and dryer.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE IV

A. PIT OF HOLLY CLAY CORPORATION, MOUNT HOLLY SPRINGS, PA.

_l 

B. SHAFT OF MOUNT EATON CLAY CO., SOUTHWEST OK SAY umSLHJHU, PA.
tJ. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE V

A. WHITTAKER RESIDUAL CLAY PIT, NARVON, I'A.

B. RESIDUAL CLAY FROM CAMBRIAN CLAYEY SANDSTONE, DUNCJAHVIN, I'A.
KAOLINS (WHITE RESIDUAL CLAYS). 87

Sodium carbonate is added in the log washer, in order to deflocculate the clay, and sulphuric acid to neutralize the alkali as the clay 

leaves the trough.

It is claimed that the plant will deliver 60 tons of washed product 

each 24 hours.

The crude clay is gritty but fairly plastic. Washing, however, 

removes most of the coarse grit and some of the fine, without increasing the plasticity much, and the Avashed clay does not appear to burn 

as dense as the crude.

The folloAving tests give some idea of the porosity and color of the 

kaolin after burning :

Physical tests of kaolin from Mount Holly Springs, Pa.

Temperature (°0.). ............................

Absorption (per cent) ..........................

Porosity (p'er cent)..... .......................

Color. .........................................

Hardness ......................................

Crude.

1,150 

3 

10 

Buff. 

Steel hard.

1,300 

0.5 

2 

Gray. 

Steel hard.

Washed.

1,150 

8.4 

19.5 

Cream-white. 

Steel hard.

] , 300 

1.5 

3.4 

Gray-buff. 

Steel hard.

Tests of a washed sample supplied by the Pennsylvania Geological 

Survey gave the following results:

Linear air shrinkage, 2.26 per cent. At cone 8 (1,290° C.), linear 

fire shrinkage, 14.12-per cent; color, grayish white. At cone 15 

(1,430° C.), linear fire shrinkage, 10.15 per cent; absorption, 0.6 per 

cent: color, grayish white. The expansion at the higher cone due 

to the high content of silica is noticeable.

Under the microscope the clays showed the following mineral 

composition:

Crude kaolin: Quartz grains of all sizes, common; hydromica 

scales, common: kaolinite, abundant: tourmaline, rutile, and zircon, 

u few grains.

Washed kaolin: Quartz grains, less abundant and all fine; 

hydromica, fairly common; kaolinite, very abundant; rutile, many 

tiny grains: epidote, rare.

Thin sections of clay that had been fired to 1,150° G. (PL XXIX. 

/?, p. 300) contained abundant grains of quartz in a groundmass 

which was mostly isotropic, though a few grains had the interference 

colors of kaolinite. The .hydromica had all disappeared. Some of 

the quartz showed signs of resorption (PI. XXIX, 5). The grains 

of rutile were not noticed. A thin section of the clay fired to 1,300° 

C. was similar to that burned at the lower temperature, but there 

appeared to be more isotropic material in the groundmass.
88. HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The washed clay fired at 1,150° C. appeared similar to the "crude, 

except that there was much less quartz, and in this specimen very 

small grains of rutile were noticed. A specimen fired to 1,300° C. 

showed the same increase in isotropic material in the groundmass 

as the crude clay.

Several samples of sands from the washing troughs were also 

examined under the microscope and gave the following results:

Head of first length of trough: Sand grains from 0.004 to 0.240 

millimeter, average about 0.12 millimeter. Grains mostly quartz, 

but some rutile, titanite, zircon, epidote, and tourmaline was present.

Bottom of first length of trough: Grains from 0.004 to 2 millimeters, average 0.1 millimeter. Same minerals, although there were 

fewer of those of high refractive index. In addition a little kaolinite was present.

Bottom of sixth length of trough: Grains from 0.001 to 0.16 

millimeter, average 0.08 millimeter. Same minerals, except that 

there was no kaolinite.

Head of eleventh length of trough: Grains from 0.002 to 0.16 

millimeter, average 0.06 millimeter. Same minerals, including a 

little kaolinite.

Beavertown. White residual clays derived from Cambrian schists 

have also been prospected in the valley of Dogwood Creek about 2 

miles west of Beavertown.

On the north side of the creek a tunnel has been run into the 

mountain in a northerly direction for over 500 feet. It first traverses the colored olay, which contains streaks of white and some 

pockets and bands of limonite, but near the end white clay is encountered. The dip of the beds is 30° N. at the tunnel entrance, 

but it steepens to 70° farther in.

The weathered, streaked schist at the entrance to the tunnel shows 

petrographic characters not unlike that of the white clay. Although 

very gritty it was. medium to fine grained, and quartz was fairly 

common. Hydromica was scarce, but kaolinite was abundant. 

Eutile was scarce, and a few grains of zircon were present. The 

grains were abundantly stained with colloidal hematite.

A second but short tunnel has been started about 75 feet higher 

than the first and about 200 feet to the south, and the clay exposed 

in this tunnel between the timbers is mostly white. It is also claimed 

that borings made on the bench of the slope show much white clay. 

This deposit has not yet been opened.

On the south side of Dogwood Creek, about 1£ miles S. 80° W. 

from Beavertown, several test pits have been put down by Mr.
KAOLINS (WHITE RESIDUAL CLAYS). 89

Fishel. The holes were all covered, but the dumps around them 

showed whitish siliceous clay.

Uses of the kaolins from the- South Mountain region. The crude 

clay from one mine has been used in the manufacture of white Portland cement.

The washed clays of this type can be used by some paper manufacturers; they are also available for making paint and can be 

employed in plaster-board manufacture. Up to the present time 

they have not been much used in the manufacture of white pottery, 

floor, or wall tile.

Future of the region. This region probably contains a considerable amount of clay, but the difficulties of mining it may prevent 

the complete extraction of the supply.

MILE

FIGURE 15. Map showing clay pits in Narvon district, Pa. 

1, Whittaker pit; 2, Diller pit; 3, Walters! pit; 4, sandstone quarry with deposit of kaolinized feldspathic 

quarlzite.

NARVON, LANCASTER COUNTY.

Residual clay derived from Cambrian schist and also from feldspathic quartzite is found at several localities in a belt extending from 

Honey brook to Narvon (fig. 15). The schist is a member of the 

Chickies quartzite and is probably coextensive with the Cambrian of 

Welsh Mountain, which forms the northwest limb of a great arch.38 

The belt of schist along the ridge is underlain by Chickies quartzite. 

This quartzite ranges from a pure quartz rock to an arkose and shows 

practically no evidence of weathering except where it is feldspathic, 

but the schists have been deeply weathered. A description of the clays

8S Personal communication from F. Bascom.
90 HIGH-G£ADE CLAYS OF THE EASTERN" UNITED STATES.

derived from the schists has no legitimate place in this report, for 

they are not high grade and are-mentioned here simply to indicate how 

the clays derived from the Cambrian in Pennsylvania may change 

from place to place.

Three openings have been made in the north slope of the ridge west 

of Narvon, and two of them are described below. The third one (said 

to belong to Dr. Walters, of Lancaster, Pa.) had not reached the 

shipping stage at the time of our visit (July, 1918).

Pit of the Whittaker Clay Co. The Whittaker Clay Co.'s pit is 

located about 500 feet southwest of Narvon station. The pit (PI. V, 

A) is a long, narrow excavation about 275 feet from end to end, made 

in the northern slope of the ridge and lying above the track level. 

At the south end of the pit the working face is probably TO feet high.

The entrance cut shows feldspathic quartzite that strikes S. 70° W. 

and dips 35° SE. This rock changes within a short distance to schist, 

having the same strike and slightly lower dip.

This schist by decay has yielded a sandy residual clay, in which the 

decomposition has gone so far that few fresh grains of mica are 

visible, but there are numerous tiny black specks. Most of the clay 

is gray, but that at the head of the pit is decidedly ferruginous. 

About 5 acres of the clay have been tested out, and the owners claim 

that it extends 140 feet below the level of the track, but this estimate is 

based on the dip of the quartzite and not on actual borings.

The clay does not burn white and is of interest here for comparison 

with some of the other deposits in this region, which are yielded by 

the same formation.

Tests supplied by the Pennsylvania Geological Survey showed that 

the clay has 2.26 per cent linear drying shrinkage. At cone 8 (1,290° 

C.) the linear fire shrinkage is 10.79 per cent, absorption 1.3 per cent,

and color buff. At cone 15 (1,430° C.) it is overfired.

The best clay is gray when dry, hard, and very gritty to the taste. 

It is quite sticky when wet. When air-dried it slakes very slowly in 

water. It probably has good bonding power.

Under the microscope it shows quartz in abundance and some 

hydromica and kaolinite, of which the kaolinite is the more abundant. 

Tourmaline grains were common (PI. XXVII, B, p. 296), and rutile 

and zircon were present but rather scarce.

Pit of the Diller Clay Co. This pit is about half a mile a little 

south of west from Narvon and also close to the railroad track. The 

excavation is smaller than that of the Whittaker Clay Co. and shows 

no quartzite. The clay is also derived from schist and is gray and
KAOLINS (WHITE RESIDUAL CLAYS). 91

iron stained and sandy, but the beds, instead of having a uniform dip, 

are folded into a syncline.

Under the microscope the clay is seen to be medium to coarse 

grained. Quartz grains are abundant. Both hydromica and kaolinite are abundant. Rutile is present in the form of numerous tiny 

grains. Epidote, titanite, zircon, and tourmaline are present but 

scarce, the tourmaline being the commonest of the four minerals.

Test shafts dug on the slope to the north show that the clay extends. 

up the hill, but its depth is not known.

Both this clay and the clay from the Whittaker Clay Co.'s mine are 

of a type used by steel works.' Where the clay has been formed 

from the schist there seems little chance of getting a Avhite product, 

but where it has been formed from the feldspathic quartzite there is 

a much better chance of getting white material. The quartzite rock 

does not decompose as readily, however, as the schist.

Uses of the clays from Narvon. The. residual clays dug near 

Narvon are not white enough to be used in paper, paints, or pottery. 

Their chief use is at steel works. .

HONEYBROOK, CHESTER COUNTY.

J. C. Budding & Co. have a large quarry in the Chickies quartzite 

2 miles northAvest of Honeybrook.

The beds dip north west, are massive, and in places feldspathic or 

arkosic. This material, however, does not seem to have decomposed 

to clay save at one point in the quarry, where a bed of arkose about 

30 feet thick has weathered to a white clay, which was worked some 

years ago. The deposit strikes northeastward. It is undoubtedly 

derived from the feldspathic sandstone, for specimens showing every 

stage in the transition from sandstone to clay can be seen. At the 

base or footwall of the deposit lies a quartz vein which contains a 

black mineral that appears to be tourmaline. The clay is very white 

but is no longer worked, as the deposit is not very extensive. This 

deposit of white-residual clay is the only one that the writer knows 

of in this district. If others are present they lie in the quartzite belt 

and not in the schist.

A sample of this kaolin, when examined under the microscope, 

was found to be medium to coarse grained. Quartz was very abundant. Hydromica was common, some of the grains being large and 

showing optical characters close to sericite; kaolinite was doubtfully 

present -in very fine grains; rutile was common in both small and 

medium sized grains. A little tourmaline was noti.ced.
92 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

KAOLIN FROM CAMBRIAN QUARTZITE IN CENTRAL PENNSYLVANIA.

By B. S. MOORE. 

GEOLOGIC OCCURRENCE.

There are a number of deposits of residual clay in central Pennsylvania (fig. 16) all of which occur under similar conditions, and

zo Miles

FIGURE 16. Map showing residual clay deposits in Huntingdon, Blair, and Center counties, Pa. 1, Blair property; 

2, Colonial Clay Co.; 3, Patton property; 4, Throop property ; 5, Petersburg; 6, Woodbury Clay Co.; 7, Rock Mill 

Clay Co. In 1, 2, 3, 4, and 6 the clay is residual from 

sandstones of Gatesburg formation; in 5 it is residual under 

Oriskany, and in 7 over Oriskany.

most of them' consist of white material. They are found chiefly in 

the Nittany Valley, and they invariably occur in Upper Cambrian 

sandstones forming a part of the Gatesburg formation.89 As they 

are distributed in a linear arrangement parallel to the strike of the 

strata of the Gatesburg they have evidently been derived from the 

weathering of argillaceous strata in that formation, which in many 

places contains beds of impure dolomite and beds of sandstone mixed 

with clay. On account of this relation between the clay and the

80 Butts, Charles, Geologic section of Blair and Huntingdon counties, central Pennsylvania: Am. Jour. Sci., 4th ser., vol. 46, p. 527, 1918.
KAOLINS (WHITE RESIDUAL CLAYS). 93

sandstone there is evidently no sharp line .of demarkation between 

the clay and the sandstone along the strike of the strata, but the 

two rocks grade imperceptibly into each other. In some pits a body 

of clay may be dug a few feet from a deposit of very fine, almost 

pure, white sand, but this sudden change is more likely to occur 

transverse to the strike of the beds than parallel to them.

The bulk of the clay comes from the borders of abandoned iron 

mines, and a great deal of clay of this type has been taken out in 

the past while the iron was being worked. The clay occurs in 

lenses, seams, and irregular masses associated with the limonite ore 

but as a rule outside the ore body, as the clay within the r area worked 

for ore is usually stained with iron. There are all gradations of 

material from clay that carries considerable iron and is of no use in 

the ceramic industry through red and pink to pure-white clay, just 

as there are all gradations between the pure clay and clay high in 

sand. The association of the clay and iron is probably due to the 

fact that the iron has been carried in solution by underground water 

and concentrated in areas where beds of argillaceous dolomite are 

associated with the sandstones. As these beds are easily weathered 

out, the sandstones break down and thus an area is formed through 

which water very readily circulates. The circulating waters readily 

remove the soluble constituents, depositing the iron oxide through 

replacement of the dolomite and leaving the insoluble argillaceous 

materials as clay. The tendency is to carry all soluble materials 

toward the center of this area, where the downward circulation of 

the water is good and to leave the insoluble materials around the 

borders of a sor.t of basin. In this basin there will be more resistant 

masses, which will not crumble down, and these may be comparatively free from iron and contain some white clay. The waters that 

enter the basin are of course carried away by good circulation underground, in some places directed and aided by fractures in the strata. 

Faults have probably in many places directed the course of the circulating waters, producing these deposits of iron and clay.

Observations show that the clay occurs as a rule along the flank 

of a ridge or knoll of sandstone, and the presence of a deposit is 

commonly indicated by a small depression in the surface. In prospecting for clay this fact should be kept in mind, but the depressions 

caused by, underground circulation should not be confused with 

stream channels, which may bear no relation to the strata from which 

the clay is derived, for streams flowing over the surface generally 

mix the clay with the other materials and spoil it for use as a white 

clay. There is no doubt that some of the clay is transported, and 

there is a concentrating process going on in these depressions by the 

underground water, but the extent of the movement of the clay 

particles is very slight.
94 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES. 

DISTRIBUTION OF THE CLAYS.

The white clays in the Gatesburg formation are being or have been 

worked at a number of localities in Center, Huntingdon, and Blair 

counties. During the summer of 1918 clay was being shipped from 

the Colonial Clay Co.'s pit near Furnace Road, just east of the Huntingdon-Center county line; the Dungarvin pit, at Dungarvin station 

in Huntingdon County; and the Woodbury Clay Co.'s pit, near 

Mines post office, in Blair County.

In addition to these properties, which have been shipping, there 

is a deposit about 2 miles west of Scotia, or Benore, in Center 

County, on which considerable work has been done. Drilling was 

carried oil all summer on another property generally known as the 

Patton property, about 2 miles east of Warriorsmark and not far 

from Dungarvin station. A considerable amount of clay has also 

been taken from the Pennington ore pits in the past.

MINES AND PROSPECTS.

Blair property. The, property controlled by Mr. Frank Blair, 

of Bellefonte, Pa., is in Center County, between Benore, or Scotia, 

and Stormstown. It covers a low ridge of Gatesburg sandstone. 

Many years ago a great deal of limonite was mined in this vicinity, 

and it is said that several thousand tons of clay were removed .from 

this area while the iron mines were in operation. About four years 

ago a further attempt was made to work the clay, and a derrick 

was erected for hoisting. A hole was dug about 30 feet deep, and 

three years later, in the spring of 1918, a shaft was sunk to a depth 

of 28 feet, in which, it is claimed, 21 feet of nearly white clay was 

exposed beneath reddish clay.

About 300 feet eastward from this shaft a pit 10 to 12 feet deep 

shows cream-colored clay, and 50 feet- northeast of this pit there 

is another, said to be 30 feet deep, that has about 14 feet of clay. 

Still another pit, about 50 feet northeast of the one last mentioned, 

shows reddish clay. Near this pit is an old drift from which clay 

was mined a good many years ago. These deposits are arranged 

roughly in a line which is approximately parallel to the strike of the 

inclosing beds.

All these workings were full of water at the time of the writer's 

visit, so that it was impossible to examine the clay deposits in detail. 

Their situation along a depression has made drainage difficult, and 

future operations must provide some means of carrying the water 

which collects there, either into the sandstone, where it is free from 

clay and porous, or by a ditch down the valley.

The clay is gritty and grades into sand, but it can be washed so 

that it is almost entirely free from grit. The color is a cream-
KAOLINS (WHITE RESIDUAL CLAYS). 95

white, and it grades into a brick-red where the clay is high in 

iron. The clay has good plasticity, even though it is coarse grained 

and gritty. Under the microscope quartz and kaolinite are seen to 

be abundant. No hydromica was noticed, but rutile is fairly common.

Physical tests on this clay gave the following result. At 1,150° 

C.: Absorption, 16.2 per cent; hardness, not steel hard; color, faint 

cream-white. At 1,350° C.: Absorption, 15.7 per cent; hardness, 

steel hard; color, faint cream-white. Another sample from the same 

deposit showed 29 per cent absorption at 1,150° C., and 19.1 per cent 

at 1,300° C.

The clay would probably be suitable after washing for white ware 

and paper making and also for pottery.

Colonial Clay Co. The property of the Colonial Clay Co. is often 

spoken of as the Gates property because it is being operated by Mr.

T. J. Gates, of Tyrone. It is in Center County just northeast of the 

boundary between Huntingdon and Center counties and about 1 

mile north-northeast from Furnace Road, a station on the TyroneScotia branch of the Pennsylvania Railroad. The clay pits are associated with the abandoned iron-ore workings, and some of them are 

in these workings. ,

The clay on this property, like that in other parts of the Nittany 

Valley, occurs as very irregular deposits in Gatesburg sandstone, 

which forms a broad, low ridge in this locality. These deposits are 

in a depression along the flank of a minor ridge on the main mass 

of sandstone, and small subsidiary depressions in the main one commonly indicate the presence of clay beneath the surfaced Their linear 

arrangement suggests that they were derived as a residual deposit 

from the weathering of certain strata in the sandstone.

At the time the writer visited the property the operations were 

being carried on in a large pit and a face of nearly white clay 

20 feet high was exposed, the clay extending from the soil at the 

top to the bottom of the pit. The white clay grades either into 

red clay high in iron or into white sand, and all degrees of variations 

may be seen. Care has not always been exercised to prevent the 

caving of the overburden, and much soil and sand have therefore 

become mixed with the white clay in some parts of the pit.

The clay is hauled in wagons to a railroad siding about threequarters of a mile distant, and the quantity shipped is stated as four 

to seven cars a week, depending upon the labor supply.

The clay has good plasticity but contains some coarse grit. Under 

the microscope it shows- an abundance of quartz and kaolinite, the 

kaolinite. being as a rule in bunches. Rutile in the form of tiny 

grains is common. Hydromica is scarce, and there are a few mediumsized grains of zircon. 

77412 22 8
96 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Physical tests made on a sample of the nearly white to cream 

clay showed that it possesses the following properties: At 1,150° C., 

absorption, 28.90 per cent; hardness, not steel hard; color, white. 

At 1,300° C., absorption, 24.80 per cent; hardness, steel hard; color, 

very faint cream-white. The plasticity is good, but the clay is gritty 

and would be improved by washing.

The crude clay is used by manufacturers of white ware in sagger 

mixtures and at steel plants, where it is employed as a binder in 

mixtures for lining Bessemer converters, hot-metal ladles, and 

cupolas.

Patton property. The Patton property lies about 2 miles east of 

Warriorsmark, in Huntingdon County. Formerly some iron was 

mined and considerable sand has been shipped from this property by 

a tramway connecting with the 'Scotia branch of the Pennsylvania 

Railroad. There is an old pit from which several tons of good paper 

clay is said to have been dug some years ago.

The West Virginia Pulp & Paper Co. has recently investigated the 

property with a view to obtain white paper clays for their mills at 

Tyrone and elsewhere. The writer is indebted to Mr. S. A. Okell, 

chemist of this company, for information regarding the work. A 

good many holes have been sunk ^y driving pipes with the aid of a 

gasoline engine.

The clay occurs in the weathered portion of the Gatesburg formation along the northeast side of a ridge of the Warrior limestone,40 

which underlies the Gatesburg, and is probably in the vicinity of a 

fault. As in other areas, it is found in the lower places, and there is 

little use in drilling on the higher land. The depth of. the holes 

drilled ranged from 50 to 75 feet, and the materials commonly encountered were sand and white or yellow clay. The depth of the 

surface material above the clay or sand ranges from 5 to 17 feet, and 

the depth of the white clay below the surface ranges from 15 to 40 

feet. The thickest body of white clay penetrated was about 33 feet 

thick and was struck at a depth of over 20 feet. The drilling indicated that the deposits are very irregular in form and of little 

horizontal extent. The clay forms pockets, and though a drill hole 

may pass through a large body of clay at one point another hole 

only a few feet away may miss it altogether, as the material grades 

into impure clay or sand.

There is a great deal of sand with most of the clay. It may 

carry from 30 to 40 per cent of free silica, but it can be readily 

washed, and a good separation obtained. Physical tests of a good 

sample gave the following results: At 1,150° C.: Porosity, 37.1 per 

cent; hardness, steel hard; color, white. At 1,300° C.: Porosity,26.9

40 Butts, Charles, op. cit.
KAOLINS (WHITE RESIDUAL CLAYS). 97

S

per cent; hardness, steel hard; color, faint cream-white. It is fairly 

plastic. . A sample of the good clay was examined microscopically. As 

was inferred from its gritty nature, quartz was very common. 

Kaolinite was very abundant, but hydromica was scarce. Rutile 

was present in the form of numerous tiny grains. There were some 

grains of titanite and a few of tourmaline.

'Not far from this locality and along the railroad is a deposit of 

residual clay and sand derived from the sandstone. The material 

is very sandy, and the pit when visited was being worked for sand, 

as the clay is insufficient in quantity to be of any commercial value. 

Its mineral composition is somewhat similar to the preceding clay, 

for it shows abundant quartz and kaolinite; fairly abundant hydromica; and a few grains of rutile, titanite, zircon, and epidote.

Dungarvin station. On the border of a large pit known as the 

Dungarvin iron mine, near the station of Dungarvin, on the Scotia 

branch of the Pennsylvania Railroad and just over a ridge of Gatesburg sandstone to the south from the Patton property, clay is being 

mined in considerable quantities. This property is controlled by 

Joseph D. Thropp, who has leased portions of it to two parties who 

are carrying on the work. Messrs. P. D. Deeters and H. F. Harpster, 

of Warriorsmark, are mining an extremely tough, plastic, pinkish 

clay, which would appear to be suitable for saggers and similar ware. 

(See PI. V, B.)

Very close to the spot .where Deeters and Harpster are working 

and on the edge of the same pit, Mr. William L. Likens, also of 

Warriorsmark, is mining a cream-colored to white clay. Some of 

this clay is very gritty, and it grades into a pure fine sand. It is 

said to be used by steel works.

These deposits are both very irregular in outline and the appearance of a working face may change rapidly from day to day. They 

lie close to the surface and right on the edge of the old ore pit. The 

white clay seems to be very similar in physical properties to the clays 

described above. The following tests were supplied by the Pennsylvania Geological Survey:

Sample 1. Air shrinkage, 6.47. At cone 8 (1,290° C.), linear fire 

shrinkage, 11.76 per cent; color, cream; absorption, 3.8 per cent. At 

cone 15 (1,430° C.), linear shrinkage, 11.76 per cent; color, bluegray ; absorption, 1.9 per cent.

Sample 2. Air shrinkage, 6.47 per cent. At cone 8, linear shrinkage, 1.47 per cent; color, cream; absorption, 16.3 per cent. At cone 

15, linear shrinkage, 0.67 per cent; color, light tan; absorption, 15.4 

per cent.

There are traces of clay in the Gatesburg formation in several 

places near Dungarvin and a thin seam similar to the clay on the
98 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Patton property may be seen in a sand bank which is being operated 

at a point close to the railroad about two-thirds of a mile northwest 

from Dungarvin.

TVoodbury Clay Go. The Woodbury Clay Co. is digging clay with 

steam shovels in an old iron-ore pit about 1 mile from Mines and 

about 6 miles from Williamsburg, Blair County. The pit is about 

900 feet long, and in places it reaches a depth of about 40 feet. 

It lies in Gatesburg sandstone, and the clay deposits are similar to 

those already described. The clay is irregular in color and distribution, being in some places nearly pure white or cream-colored and 

in others a dirty gray, though it weathers white. It grades into 

sand, and it fills cracks and pores in the weathered sandstone, indicating that it has been derived from the weathering of a clayey 

sandstone.

From this deposit about four carloads a day were being shipped 

in the summer of 1918.

POSSIBILITIES OF FUTURE DEVELOPMENT.

The typical association of white clays with the sandstones of the 

Gatesburg formation in central Pennsylvania suggests that this formation may contain deposits in the wooded areas underlain by it. 

Although these deposits are generally associated with the limonite 

ore, which has been so extensively worked in this section in previous 

years, and most of them have doubtless been discovered in working 

the iron, the writer believes that other clay-bearing areas may be 

found. The sandstones of the Gatesburg formation should not be 

confused with the Eidgely sandstone of the Oriskany group, which 

is much later geologically than the Gatesburg, but which also 

contains iron ore and clay in some localities. Near Shirleysburg 

the Oriskany group carries a good deposit of clay in its upper strata 

(Eidgely sandstone), and in some other places clay occurs lower 

down in the group and at its base. This younger sandstone is the 

deposit so widely used in Pennsylvania for the manufacture of glass 

sand, but the sandstones of the Gatesburg are not suitable for this 

purpose.

USES OF THE KAOLINS FROM CENTRAL PENNSYLVANIA.

The kaolins from the Gatesburg formation appear to be shipped 

chiefly to steel works. Some of them are white enough in their unbufned condition to be used in paper manufacture, but for this purpose they have to be washed in order to free them from the grit 

that they contain, and this is done. Of course, this work involves 

the construction of a washing plant, which would not be warranted 

unless there was a sufficiency of material in sight. As they do not 

turn white it is questionable whether they could be used in the manufacture of white ware. The white clay, if sufficiently free from grit
KAOLINS (WHITE RESIDUAL CLAYS). 99

when washed, might also be used by the paint and rubber trade. 

Not a little of the crude clay is used in sagger manufacture by different firms in the United States and Canada.

KAOLIN FROM FELDSPATHIC QUARTZITE IN CONNECTICUT.

A unique deposit of kaolin west of West Cornwall, Conn., is derived from a somewhat steeply dipping feldspathic-quartzite. Here 

and there in the deposit beds of unweathered sandrock occur. The 

material has been extracted chiefly by underground mining, and because of the mode of occurrence some difficulties have been encountered in the operations.

The crude clay is. very silty and has to be washed before being 

marketed. It is obtained by forcing water down a pipe into the 

deposit, loosening the material, and then pumping the water and 

suspended clay up another pipe to the surface. It is then carried 

through a 6-inch pipe line to the washing plant down in the valley 

along the New York, New Haven & Hartford Railroad track. The 

mine has been an intermittent producer for the last 20 years, and 

the product is said to be marketed as a paper clay. It was not 

operated in 1918. The following notes on this clay are given by 

Loughlin:41

Analysis of kaolin from West Cornwall, Conn.

Silica (SiOa )__________________ __ 47.50 

Alumina (AUOs)______________ ___ ______ 37.40

Ferric oxide (FesOa)_____________________ .80 

Lime (OaO) ________..__________________ Trace. 

Magnesia (MgO) 

Alkalies (Na2O+K2 0)______________________ 1.10 

Water (H2O)__________________________ 12.48

99.28

The washed clay is very white, is rather granular to the feel, and apparently 

lacks plasticity, but several experiments and practical tests have shown that 

whgn mixed in a body the mixture is equal in plasticity to that of bodies made 

from other kaolins. The burned clay is very white and begins to show a mere 

tinge of yellow, due to the small amount of iron present, when heated to a high 

temperature such as would be required in the manufacture of china.

KAOLIN FROM CAMBRIAN SHALE IN VIRGINIA.

Investigations made, in recent years by the Virginia Geological 

Survey have revealed a number of deposits of white to light-gray 

residual clay along the western side of the Blue Ridge, or on the 

eastern side of the Great Valley, in Virginia.

All these deposits appear to have been derived by the weathering 

of the steeply dipping Cambrian shales which rest on the quartzite

** Loughlin, Q. F., The xclays and clay industries of Connecticut: Connecticut GeoL 

and Nat. Hist. Surrey Bull. 4, p. 57, 1905.
100 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

that forms the west slope of the Blue Ridge. The development of the 

deposits of iron and manganese ores in this same belt has probably 

led to the discovery of several of the kaolin deposits. Most of the 

deposits that have been discovered or tested lie between Basic City, 

Augusta County, and Balcony Falls, Rockbridge County. Some have 

been reported farther north and even on the west side of the valley, 

near Buffalo Gap, Augusta County.

The area within which prospecting should be carried on is that 

underlain by the. formation with which these kaolins are associated. 

However, as the deposits lie on the slopes of the mountain, the clay 

is commonly covered by a deposit of soil and stones of varying 

thickness.

The following information regarding these deposits is abstracted 

from a report of the Virginia Geological Survey.41*

LIPSCOMB, AUGUSTA COUNTY. C

Several discoveries of whitish residual clay have been made in the 

area south of Lipscomb and east of Stuarts Draft, most of which 

were found in digging wells. The clay, which in places lies within 8 

feet of the surface, shows a variable amount of iron mottling and 

streaks of sand. It apparently is also cherty in some places, suggesting that some of it at least may be derived from limestone.

The only locality in this area where a systematic attempt has been 

made to extract any of this white clay is about one-half mile southwest of Lipscomb, on the property of J. W. Goode. The clay from 

this locality was used after the Civil War for Rockingham ware and 

at a later date for fire bricks. Some of it was also washed and shipped 

to potteries. At present the clay can only be examined in an abandoned shaft.

The following tests of clay from this shaft have been furnished by 

the Virginia Geological Survey:

Tests of clay from shaft on Goode property, near Lipscomb, Va.

Water of plasticity..............................................per cent..

Plasticity................................................................

Air shrinkage.............................................................

Cone 010 (950° C.):

Fire shrinkage............................'.............................

Absorption...........................................................

Cone 05 (1,050° C.):

Fire shrinkage........................................................

Absorption...........................................................

Cone 1 (1,150° C.):

Fire shrinkage........................................................

Absorption...........................................................

Cone 9 (1,310° C.):

Fire shrinkage........................................................

Absorption...........................................................

50

Good. 

8.6

9.7 

28.1

16.4

7.76

45

Good. 

9.3

7.3 

28.9

11.3

11.5

45 

Good.

3.4 

31.4

3.7 

31.6

1. White clay with yellow streaks, representing the best material.

2. Washed sample of No. 1.

3. Second-grade clay.

410 Ries, H., and Somers, R. E., The clays and shales of Virginia west of the Blue 

Ridge: Virginia Geol. Survey Bull. 20, 1920.
KAOLINS (WHITE RESIDUAL CLAYS). 101

All three samples burn cream white and become steel hard at cone 

05 (1,050° C.). There is not much difference between the washed and 

unwashed clay, except in the shrinkage and absorption at cone 9 

(1,310° C.), which is probably due to the fact that the sample obtainable contained but little sand.

The material does not burn white enough for white earthenware. 

It might be used in the commoner grades of paper stock or even 

in other industries where a whitish clay comparatively free from 

grit is demanded, but it would have to be washed before shipment 

to market

COLD SPRING, AUGUSTA COUNTY.

A deposit of limonite was formerly worked on the mountain slope 

about 2 miles southeast of Cold Spring station on the Norfolk & 

Western Railway. In running a tunnel from the mountain slope into 

the pit a body of white clay about 100 feet thick was encountered. 

Other test pits showed that the clay continued southward along the 

strike for fully 600 feet, but nothing further in the way of development was done for some years. Recently the clay has been opened 

to a depth of about 60 feet without reaching bottom. (See PI. VI, A.) 

 Of course it is impossible to tell how deep the clay extends, but its 

depth may be considerable, as the rocks on the mountain slopes have 

been deeply weathered. .-

The overburden, which consists of dirt and waterworn quartzite 

cobbles, differs in thickness from place to place and will probably 

average not less than 15 or 20 feet, but in view of the probable size 

of the deposit it will not prove to be a great obstacle to development.

The clay is dense, massive, and free from bedding planes, as the 

stratification of the shale rock has been but little preserved. It is 

white to light gray and contains little grit, but the cracks in the 

upper part of the deposit show light stains of iron oxide. An analysis of the material gave the following results:

Analysis of kaolin from Cold Spring, Va.

Silica (SiCM_________________-________ 43. 31 

Alumina (A12O3 ) _________________________ 39.42 

Ferric oxide (Fe2O3 )___ - __' - - 2.86 

Lime (CaO)___________________________- 0.00 

Magnesia (MgO)___________ __ .04

Potash (K2O)_________________!_________ __ .25

Soda (Na2O)____________ _____________ .30 

Loss on ignition_____ ___.. 13. 58

99.76

This clay has an unusual composition in that the proportion of 

silica to alumina is much lower than that required for kaolinite.
102 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Under the microscope the material was seen to be medium to fine 

grained. There was practically no quartz, and only a few grains 

of hydromica. Kaolinite was abundant, and there were also a number of very fine grains of indeterminable character. Kutile was 

abundant, both in grains and tiny needles. A few grains of tourmaline and zircon were present.

The following tests of this clay were made in the laboratory of 

the Bureau of Mines at Columbus, Ohio:

General physical tests of white residual clay from Cold Spring, Va.

Workability _______________Plastic, smooth, fair drying. 

Water of plasticity_ ______________per cent 41. 32 

Air shrinkage, by volume __ ___do 16.48 

Air shrinkage, linear, calculated____________do__ 5.5 

Modulus of rupture:

Raw clay____ _ pounds per square inch 47.1 

Mixture of clay and sand in proportion of 1:1_do__ 21.36 

Screen test: Residue on 330-mesh sieve______per cent_ 24.66

Fire tests of white residual clay from Cold Spring, Va.

Temperature 

(°C.).

1.190

1.250

1.310

1.370

1,410

Porosity 

(per cent).

39.30

36.67

33.24

30.70

18.90

Color.

.....do....................................................

.....do....................................................

Volumetric 

shrinkage 

(per cent 

in terms of 

volume of 

dry clay).

22.40

28.05

31.26

34.30

42.30

Linear 

shrinkage 

(per cent 

in terms of 

dry clay).

8.0

.10.4

11.8

13.1

16.8

Fusion point, cone 31. Nearly steel hard at 1,310° C.; steel hard at 1,370° C. 

Develops small surface cracks in burning.

The clay has very low bonding strength and is not to be classed as 

a bond clay nor does it fire to a very dense body. Its color after firing 

is not sufficiently white for white ware. Its refractoriness is fair.

The deposit is operated by the Product Sales Co., of Baltimore, 

Md.

The chief use for this clay seems to be in paper, paint, and rubber 

manufacture. A small quantity of it might be used in some ceramic 

wares, but the chief objection to it is that it does not burn white. Experiments have shown that it can be used in electrical porcelain.

LOFTON, AUGUSTA COUNTY.

Another deposit of Cambrian residual clay occurs on the property 

of A. K. Shulz, on the east side of the Norfolk & Western Kailway, 

about one-half mile northeast of Lof ton station.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE VI

A. PIT OF PRODUCT SALES CO., COLD SPRING, AUGUSTA COUNTY, VA.

B. SHALLOW SHAFT AND HOISTING DRUM AT KAOLIN MINE NEAR 

LUTESVILLE MO.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE VII

A.. COX FLINT-CLAY PIT, NORTH OF HOFFLIN, MO.

B. SASSMAN FLINT-CLAY PIT, OWENSVILLE, MO. 

One of the few pits in which a distinctly bedded structure was observed.
KAOLINS (WHIT.E RESIDUAL CLAYS). 103

The deposit underlies a swamp of about 15 acres extent and is not 

less than 40 feet deep. The material is grayish white in its upper 

part but at depth shows light-yellowish mottlings.

The clay is fine grained and very plastic. Though it was derived 

by the weathering of Cambrian shale it has a somewhat different 

composition from the material southeast of Cold Spring, as shown 

by the following analysis :

Analysis of clay from Lofton, Va.

Silica (SiOa )_____________________________ 52.10 

Alumina (AhOa)__________________________ 31.54 

Ferric oxide (Fe2O8 )_______1____L__________ 2.38 

Lime (CaO)_____________________________ .10 

Magnesia (MgO)__________________________ .58 

Potash (K80)___:_______________________ 1.89 

Soda (Na20)_.________________^_____ .27

Loss on ignition_____________ _____1_ . 10.89

99. 75

The physical tests gave the following results: Water of plasticity, 

47.7 per cent; plasticity, good; air shrinkage, 8.1 per cent.

Fire tests of clay from Lofton, Va.

Temperature (°C.).

l.OOO...../.........................................................

1.160............. ..................................................

1,250...............................................................

1, 410 ...............................................................

Fire 

shrinkage.

3.37

12.50

15.00

15.00

Absorption.

21.70

6.49

.18

.16

Porosity.

42.49

15.58

The clay burns steel hard at cone 08 (990° C.) and develops a 

creamy-white color. This clay, in strong contrast to the clay from 

Cold Spring, shows very high fire shrinkage and burns very dense.

This high shrinkage would interfere with the use of the clay alone 

in burned wares, although it might be used in small quantity.

It could be used unburned for purposes in which a light-gray clay 

of good plasticity is desired, possibly rubber or paints.

VESUVIUS, AUGUSTA COUNTY.

A deposit of white residual clay occurs on the property of T. L. 

Shelton about 2f miles northeast of Vesuvius. Borings are said to 

have shown a length of 240 feet and a depth of about 30 feet. The 

width of the deposit is not known.

The clay has fair plasticity. One sample burned at cone 9 (1,310° 

C.) had a total shrinkage of 10 per cent and absorption of 18.9 per 

cent. Its color was cream-white and it was steel hard.
104 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

BUENA VISTA, ROCKBRIDGE COUNTY.

Excavations for limonite along the foot of the Blue Ridge, northeast of Buena Vista, have revealed pockets of yellowish and white 

residual clay, mostly of small size.

One large mass 1£ miles northeast of the town has been worked for 

some years to make fire brick.

This clay, which is somewhat gritty, had 28 per cent water of 

plasticity, was quite plastic, and had 4 per cent air shrinkage. The 

fire tests are given below:

Fire tests of clay from Buena Vista, Va.

Cone.

010 (950° C.)-. -......-......;... ...............................................

03 (1,090° C.)....................................................................

1 (1,150° C.)..................-.............................-....................

9 (1,310° C.)......-..-...........-...............................................

Fire 

shrinkage.

3

1

4

6.6

Absorption.

27.7

23.0

16.55

12.00

The clay burns to a cream color and is nearly steel hard at cone 03. 

It would not be suitable for making white ware.

KAOLINS PROM CAMBRIAN LIMESTONE IN MISSOURI.

General features of the deposits. Wheeler, in his report on the 

Missouri clays,4* says:

All the kaolin thus far found in Missouri occurs south of the Missouri River 

on limestones of Paleozoic age. The belt containing it is extensively worked 

in Cape Girardeau and Bollinger counties, in the southeast, from whence it 

extends to Howell County, forming the southeastern kaolin district. It is also 

worked, but much less extensively, in Morgan and Cooper counties, in the

central part of the State, which is called the central district.

It is found, though thus far not worked, near Aurora, in Lawrence County, 

which is known as the southwestern district.

In the first district the kaolin, according to Wheeler, is associated 

with Ordovician and Cambrian limestones, in the second with upper 

members of the Ordovician limestones, and in the third with early 

Carboniferous or Mississippian limestones.

Since Wheeler's report was published kaolin mining has decreased, 

and the only mines now in operation are in the southeastern district. 

The counties of Cape Girardeau and Bollinger, in this district, ranked 

highest, Bollinger being the more promising of the two. In Bollinger County the present-day mining is being carried on.

In former years some of these clays were utilized by local potteries and others were shipped as far even as East Liverpool, Ohio.

« Wheeler, H. A., Clay deposits: Missouri Geol. Survey, vol. 11, p. 161, 1896.
KAOLINS (WHITE RESIDUAL CLAYS). 105

Lack of transportation facilities has probably prevented the use of 

these clays if they occur in sufficient quantity. There is only one railroad line across Bollinger County, and the roads for hauling the clay 

from the mine to the railroad are poor. Careless mining may also 

have hindered development, for, according to Wheeler, and the 

writer's work corroborates his statement, care must be taken in selecting the material for shipment. Washing might improve the clay, 

but a washer should not be erected unless an adequate supply of clay 

is assured.

These kaolins were the subject of a somewhat exhaustive study 

some years ago by Orton,43 who states their properties as follows :

The proportions of kaolin 44 and silica vary from 30 per cent kaolin and 70 

per cent sand in sample 16 to 60 per cent kaolin and 40 per cent sand in sample 

7. The average is represented by sample 10 containing 45 per cent kaolin and 

50 per cent sand. * * *

They are immensely fine grained. The coarsest contained 60 per cent of material which would pass a 200-mesh screen. The finest passed 200 mesh completely. Sample after sample lost less than 10 per cent in passing 200 -mesh.

They are very weak, on account of the large quantity of fine silica. They 

crumble like chalk when dry and show almost no tensile strength. They are 

plastic as any fine-grained mass is plastic, but they have almost no fatness or 

cohesion or bonding power. They would not do to add to other clays as a 

bond. * * * They shrink little in drying. * * *

They shrink but little at a high temperature, remaining soft and porous. 

* * * They remain or become most unusually white on firing to a high 

temperature.

Orton called attention to the fact that even the stained clays may 

burn white. He expresses the belief that the silica in them is so finegrained that it will be difficult to eliminate by washing.

There is no doubt that the deposits of Bollinger County represent 

a rather uncommon type of kaolin.

The country rock is chiefly dolomitic limestone, which is generally 

cherty and in places contains cavities lined with crystals of calcite. 

It is evident that the clay in this region is all residual and has been 

derived from the weathering of dolomite.

As Orton pointed out, it is somewhat irregular in its occurrence, as 

the white clay and the stained clay are more or less mixed. Consequently, in order to select the whitest and leave the poorest material 

in the ground, the stopes in the mines are somewhat irregular. The 

writer can not estimate how much white clay there is in the district, 

but from what he saw he is inclined to believe that its occurrence is 

probably pockety.

A brief examination Was made of several samples collected from 

this district, which showed some variation in their characters.

*» Orton, Edward, Jr., The kaolin deposits of Bollinger County, Mo.: Am. Ceramic Soc. 

Trans., vol. 9, p. 62, 1907.

u By kaolin Orton evidently means the clay particles.
106 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Sample graded as No. 1, from an operating mine, had very fair 

plasticity. It was medium grained, and under the microscope the 

small quartz grains were seen to be fairly common; hydromica was 

fairly abundant and commonly coagulated; kaolinite was abundant; 

rutile was scarce; and only a grain or two of epidote and chlorite 

could be seen.

The clay behaved as follows in burning:

Fire test of kaolin No. 1, from Bollinger County, Mo.

Temperature (°C.).

l,150o..................................................

1,300....................................................

Absorption 

(per cent).

6.2 

0

Porosity 

(per cent).

14.4

.8

Color.

Faint cream-white. 

Buff.

o Steel hard.

This sample evidently burned denser than the samples tested by 

Orton.

Thin sections of the burned clay, when examined under the microscope, showed grains of quartz embedded in a fine-grained mass, 

which was partly isotropic and partly composed of crystalline grains 

showing the interference colors of kaolinite.

As all the hydromica had disappeared at 1,150° C., there was little 

difference in the appearance of the clay burned at the two temperatures.

Grade No. 2 from the same mine was distinctly more gritty and 

mottled with stains of limonite. When wet it was plastic.

Under the microscope this material was seen to be medium to fine 

grained. Quartz was very common; hydromica, common; kaolinite, 

abundant; rutile, in very numerous tiny grains; epidote and tourmaline, a few grains.

Two fire tests yielded the figures given below:

Fire tests of kaolin No. 2, from Bollinger County, Mo.

Temperature (°C.).

1150o

l'300o

Absorption 

(per cent).

8.7

7.6

Porosity 

(per cent).

22.9

18.4

Color.

Buff.

o Steel hard.

A third sample, which had moderate plasticity when wet but was 

almost chalklike when dry, behaved quite differently from the above 

in the fire tests.
KAOLINS (WHITE RESIDUAL CLAYS). 107 

Fire tests of kaolin of sample No. 8, from Bollinger County, Mo.

Temperature (°C.).

1.150.................................................................

1,300................................................................

Absorption 

(per cent).

29.7

26.9

Porosity 

(per cent).

44.4

42.8

Color.

White.

Do.

This clay,,it will be seen, is a much more open burning clay than 

the others.

Several companies have clay holdings in this region, but only 

two have been doing any mining recently.

Property of American China Clay Go. The American China Clay 

Co., of Lutesville, Mo., is mining clay ty miles southwest of Lutesville. It owns 120 acres and has 800 acres more under lease.

In June, 1918, it was operating a new shaft 50 feet deep. (See PI. 

VI, B.) This shaft showed an overburden of cherty iron-stained clay 

but stopped in grayish-white clay. Three drifts had been run from 

the bottom of the shaft at right angles to each other. The longest 

drift runs S. 50° E. for 50 feet and then runs S. 20° E. for 25 feet.

The clay, which is dense and plastic, shows traces of bedding 

planes, and contains scattered nodules of chert, which is called spar 

by the miners, but in places these chert lumps are arranged in lines, 

just as they occur in the fresh rock, and may follow directions of 

bedding. The chert is gray, white, or in places iron stained, and 

some of it shows a fine zonal structure. These chert bands, which 

average 6 to 8 inches in thickness, are commonly wavy and show a 

distinct dip, whereas the dolomite beds on the surface (but not near 

the shaft) are practically flat. If the inclined layers of chert represent the position of the.bedding planes, it is possible that these have 

been disturbed by faulting, as a steep fault plane that strikes S. 32° E. 

was observed in the mine. The striations on it were vertical. The 

face of the fault is iron-stained and so is the clay bordering the fault.

Two grades of clay are sorted out, known as No. 1 and No. 2, but 

they are separated by hand picking, for there is no regularity of 

their occurrence in the deposit. Indeed, the presumption based on 

underground observations is that the occurrence of the whitish clay 

may be more or less irregular. That the white clay occurs at other 

points in the deposit is shown by the fact that an earlier shaft, 80 feet 

distant from the present one, in a direction N. 60° W., penetrated 

the whitish clay. Again, a test pit sunk about 400 feet, S. 50° W., 

from the present shaft showed white clay close to the surface.

The clay is all hauled to Lutesville, where it is delivered to the 

mill of the Sampson Plaster Board Co. This company does not 

wish to publish any details regarding the method of treatment at
108 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

their mill. The writer was told tha,t some of the clay was also 

used in china and paint manufacture.

BauscTi mine. Another operator in this district is F. E. Bausch, 

of St. Louis, who has sunk two shafts. One of these shafts, not 

open to inspection, is 2 miles due west of Glen Alien and 2£ miles 

northwest of Lutesville. It is said that the clay in one shaft is less 

than 7 feet below the surface and 30 feet below in the other, but. in 

both deposits the good clay is more or less pockety. The shaft that 

was visited passes through a 3-foot bed of quartzite about 30 feet 

below the surface.

The clay has to be sorted by hand. The No. 1 grade, known as 

chalk clay, is quite white when dry, whereas the No. 2 grade is light 

gray and shows some iron stains. The material on the dump contains the same kind of chert nodules that were found in the other 

deposit.

KAOLINS FROM SHALES AND LIMESTONES OP THE ORISKANY 

GROUP IN THE APPALACHIAN STATES.

OCCURRENCE AND DISTRIBUTION.

The Oriskany deposits of the Devonian are widely distributed in 

the Appalachian States from New York southward. The sandstone 

of the Oriskany does not weather down to clay except where it is 

f eldspathic, but in some localities beds of shale and impure limestone, 

the latter somewhat cherty, are associated with it, and in these localities the beds may yield clays when broken by weathering. Although these clays have been known, locally at least, for many years, 

no one seems to have considered the isolated occurrences as a special 

group whose representatives are so widely distributed as to make 

the search for additional deposits worth while.

Natural conditions in places render prospecting troublesome, for 

the Oriskany of the Eastern States usually occurs in regions of highly 

folded rocks. Therefore, because of its resistant character it commonly forms prominent ridges, and as the clay-yielding rocks seem 

as a rule to underlie it, the clay deposits occur mostly on the ridge 

slopes, where they may be covered by wash, and this perhaps in turn 

by a forest growth. To find the clay, therefore, means much trenching, digging many test pits, and much boring.

The areas in which the deposits may occur are indicated on the 

geologic maps of Pennsylvania, Maryland, Virginia, and West Virginia, by the distribution of the Oriskany formation.

Two other facts should be emphasized first, that the shales and 

limestones of the Oriskany have not been weathered to residual clays 

throughout their extent, and second, that the residual clays formed as 

above described may range from ferruginous to white materials.
KAOLINS (WHITE RESIDUAL CLAYS). 109

The white clays of course are the only ones of interest in the present 

discussion.

The localities thus far known at which these Oriskany clays may 

occur are: Saylorsburg, Monroe County, Pa.; Petersburg and Shirleysburg, Huntingdon County, Pa.; Hampshire County, W. Va.; 

Frederick County, Va.; and Lignite, Botetourt County, Va. Of 

these localities, Saylorsburg is the most notable, but clay is being 

worked at Petersburg and Shirleysburg also. The other localities 

are undeveloped.

PENNSYLVANIA.

SAYLORSBURG DISTRICT.

GEOLOGY. 

By F. B. PECK.

The clays at Saylorsburg have been formed by the Aveathering of 

calcareous sandy shales and cherty limestones that underlie the 

sandstone of the Oriskany. This sandstone forms a prominent ridge, 

which extends from the Delaware Water Gap southwestward through 

Saylorsburg and beyond. Its thickness increases from about 50 feet 

on Delaware River to nearly 200 feet on the Lehigh. Underlying 

this sandstone there is a series of gray calcareous shales,, which is 

best developed in the region around Stormville and called the 

" Stormville series" by the Second Geological Survey of Pennsylvania. 45 These strata are approximately 100 feet thick in the Saylorsburg district and in their lower portion include some beds of 

cherty limestone. They thin out in a short distance southwestward 

toward the Lehigh and are replaced by coarse gritty Oriskany sandstone.

Under the " Stormville series" (of Helderberg age, except its 

uppermost beds, which are of Oriskany age) 46 is the Bossardville 

limestone,47 which is about 90 feet thick; the upper two-thirds is very 

slaty, and the lower third is a banded limestone.

The clay mines all lie on the northern slope of Chestnut and Cherry 

ridges (fig. IT), which structurally are formed by a series of parallel 

folds in the Bossardville, " Stormville," and Oriskany formations. 

The clay is found near the summit of an anticline that parallels the 

crest of the ridges but lies on their northwestern slope, so that the 

clay beds dip southeastward at steep angles (60° to 90°) into and 

under the ridges. The same beds outcrop in places on the south45 White, I. C., The geology of Pike and Mouroe counties: Pennsylvania Second Geol. 

Survey Kept. GG,. pp. 128, 131, 1882.

«° Reeside, J. B., U. S. Geol. Survey Prof. Paper 108, p. 186, 1917. 

« White, I. C., op. cit, p. 141. 1882.

77412 22 -9
110 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

eastern slopes of the ridges, but there they do not seem to have altered 

to clay.

The formation of the clay, therefore, is due to a local weathering 

of the " Stormville " and Bossardville beds along a stretch of about 

3 miles, Saylorsburg being about midway in this distance.

In the eastern part of the Saylorsburg region the white clay seems 

to have been derived from the " Stormville shale series," and it immediately underlies Oriskany sandstone. The clay, which contains 

much fine sand, is about,23 feet thick.

In the Mount Eaton district, 1| miles southwest of Saylorsburg, 

the clay appears to have been formed from the upper slaty member

X Prospect a Shaft Plant

FIGURE 17. Map showing location of shafts in white residual clay in Saylorsburg district, Pa. 1, Atlas Portland Cement Co.; 2,. Keystone Clay & Reduction Co.; 3, 

Mount Eaton Clay Co.

of the Bossardville limestone, and the " Stormville series " has diminished materially in thickness. The No. 1 white clay beds, are 6 to 20 

feet thick, but lie 50 feet stratigraphically below the hard Oriskany 

sandstone, instead of immediately below it, as at the eastern end ot 

the clay belt in the Atlas Portland Cement Co.'s mine, 1£ miles 

northeast of Saylorsburg.

The distribution of the clay seems to coincide with a former drainage system, the remnants of which are seen in the Wind Gap of Blue 

Mountain and the two gaps in Chestnut and Cherry ridges, the one 

at Saylorsburg and the other 1£ miles southwest of Saylorsburg, 

where the highway crosses Chestnut Ridge, north of Mount Eaton.
KAOLINS (WHITE RESIDUAL CLAYS). Ill

Immediately under this drainage system the lime has been leached 

from these rocks and they have been altered to clay.

CHARACTEE AND USES OF THE CLAYS.

The residual clays of this region are in part white and in part 

colored, but only the white clays are utilized. They are very gritty, 

and the sandy impurities are mostly very fine grained.

In their crude form the clays are used in the manufacture of white 

Portland cement. For all other purposes they have to be washed. 

After treatment clays of this type can be utilized as a filler for certain 

grades of paper, in paint manufacture, and as a filler for rubber. 

Preliminary tests of some of them indicate the possibility of their use 

in pottery, but most of the clays from this region do not burn sufficiently white.

MINES.

.Three companies are operating in the Saylorsburg region at present. 

A fourth one formerly operated at Kunkletown, to the southwest. 

(See fig. IT.)

Mine of the Keystone, Clay & Reduction Go. The mine of the 

Keystone Clay & Reduction Co. is at Saylorsburg. (See. fig. IT.) 

The deposit is worked by means of a shaft. As much clay as possible 

is worked through one shaft, and then another is sunk. Altogether 

eight shafts have been sunk, which range from 45 to 116 feet in 

depth and average 90 feet.

At the bottom of the present shaft, which is 45 feet deep, a drift 

has been run 100 feet to the southeast. The bottom of the shaft is in 

black clay, and the drift cuts it for 20 feet; then comes 50 feet of gray 

No. 2 clay, and finally 30 to 36 feet of white No. 1 clay. The last 

two clays are mined. The beds in this locality form an arch. The 

shaft is nearly on the crest, and the level has been driven on the 

south, limb. The hanging wall overlying the No. 1 clay is Oriskany 

sandstone.

A sample of the crude clay from this mine that was examined under 

the microscope showed a medium to fine grain. Quartz was very 

common, slivers of hydromica were rather abundant, kaolinite was 

very abundant, and minute needles of rutile were also abundant. 

Several small rounded grains of a titanium mineral and also a little 

tourmaline were present.

A sample of the washed clay was medium to fine grained, and the 

grains were of quite uniform size. Quartz was in much smaller 

quantity than in the crude clay, needles of hydromica were rather 

abundant, kaolinite was abundant, and needles of rutile were very 

numerous and small.
112 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The clay shows fair plasticity and burns steel hard at 1,150° C. 

Some additional properties after firing are stated below:

Fire tests of washed clay from Saylorsburg, Pa.

Temperature (°C.).

1,150.............................................. ..... . .........

1,300.... ................................ .............................

Absorption 

(per cent).

i

0

Porosity 

(per cent).'

5.9

.4

Color.

Buff.

Gray-buff.

Thin sections of the clay fired at the temperatures stated in the 

table showed a finely granular aggregate of quartz grains in a finegrained groundmass, which is more or less isotropic. At 1,150° C. 

the hydromicas had nearly disappeared, and at 1,300° C. none remained. The grains of rutile existed at the higher temperature, and 

some grains that showed the interference colors of kaolinite were still 

present.

Another sample, representing the second-grade crude clay, differed 

from the first grade in being more gritty and also in being stained 

somewhat with limonite.

This sample under the microscope showed quartz, abundant kaolinite and hydromica, and a few grains of rutile. The material is 

quite plastic, but at the lower temperature it burns more open than the 

washed clay, as shown by the tests below:

Fire tests of No. 2 crude clay from Saylorsburg, Pa.

Temperature (°C.).

1,150................................................................

1,300................................................................

Absorption 

(per cent).

8.6

0

Porosity 

(percent).

21.9

.5

Color.

Buff.

Gray-buff.

The clay was steel hard at the lower cone.

The burned clay under the microscope showed a granular aggregate of quartz in a fine-grained groundmass, which was mostly 

isotropic! Eutile was still in evidence at 1,300° C.

Tests made for the Pennsylvania Geological Survey of a sample 

from Saylorsville gave the following results: Air shrinkage, 3.42 per 

cent. At cone 8 (1,290° C.), linear shrinkage, 11.97 per cent; absorption, 0; color, grayish white. At cone 15 (1,430° C.), overfired.

Property of the Mount Eaton Clay Co. The plant of this company 

is on the northwest side of Chestnut Ridge, about 1^ miles southwest 

of Saylorsburg. (See fig. IT.) The deposit was opened by sinking 

a shaft 90 feet deep, from which a drift that ended in hard shaly 

sandstone was run S. 25° E, for 250 feet. (See PI. IV, B.)
KAOLINS (WHITE RESIDUAL CLAlfS). 113

At a distance of 200 feet from the base of the shaft there are two 

crosscuts that run at right angles to the drift. One of these crosscuts runs 200 feet southwest and the other. 100 feet northeast. Both 

of them are in clay. The shaft penetrated first 25 feet of wash, then 

15 feet of discolored clay, and 50 feet of white clay that^contained 

fragments of chert.

The clay body appears to dip 55° SE. It seems to have been 

derived, in part at least, from a cherty limestone at the base of the 

Oriskany, and the fragments of chert may occur as isolated lumps or 

in lines parallel with the original bedding planes.

The best clay is white and finely gritty and may be sandy along 

certain layers. After mining, the clay is sent down the gravity incline 1,200 feet long to the washing plant, and the washed product is 

hauled 2 miles to the railroad at Saylorsburg.

Property of the Atlas Portland Cement Co. This company has 

put down a line of shafts northeast of Saylorsburg on the southeast 

side of the highway. ('See fig. 17.) These shafts are irregularly 

spaced, and as soon as the clay within workable distance of one is 

exhausted another is sunk.

Shaft No. 7, which was being worked during the summer of 1918, 

had been sunk to a depth of 90 feet. The clay averaged 30 feet in 

thickness and was penetrated less than 22 feet below the surface. The 

shaft had two levels, one at 60 feet and the other at 90 feet. The 

drift from the foot of the shaft passed first through discolored cherty 

clay before the white clay was reached. The white clay is fairly 

plastic and gritty and contains scattered lumps of chert from the 

original limestone. All the product is used in the manufacture of 

white Portland cement.

Under the microscope the clays show a medium to fine grain Avith 

scattered fine dustlike grains. Quartz is common, as is also hydromica, and kaolinite is abundant. Tiny grains of rutile are very 

numerous. Grains of tourmaline and zircon are also present.

The crude clay does not fire as dense as that mined at Saylorsburg, 

as the following partial tests show:

Fire tests of cmde clay from mines northeast of Saylorsbiirff, Pa.

Temperature (°C.).

1,150 a..............................................................

1,300................................................................

Absorption 

(per cent).

31.2

Porosity 

(per cent).

1.5

2 a

Color.

Buff.

Light gray.

a Steel hard.

The appearance of thin sections of the burned clay was -much like 

that described from the preceding mine.
114 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES*. 

KTJNKLETOWN, MONROE COUNTY.

Some years ago a brick plant was erected at Kunkletown, and 

obtained its clay from the ridge about three-fourths of a mile northeast of the works. The material was brought down by a wire-rope 

tramway. The brick works is no longer' in operation, but the excavation made on the ridge was a large one, and a> considerable quantity of clay was, no doubt, taken out, for the pit is about 50 feet 

deep and 400 feet long. Unfortunately, the walls have slid considerably, so that it is difficult to get much information regarding the 

relationships of jthe clay deposit. On the east side of the excavation Oriskany sandstone forms a steep hanging wall, and the foot 

wall on the west is black shale, also of Oriskany age. The black 

shale is not well shown in the pit, but outcrops in a fresh condition 

near the works. The only clay visible is a mass of mottled, ironstained, sandy material at the entrance to the cut.

A boring in the southeast corner of the pit showed a grayish-white 

gritty clay that contained" mottlings of limonite, which may be of 

superficial character. It is claimed that borings have been made 

in this clay to a depth of over 20 feet. Much more boring would 

have to be done to demonstrate the extent of the clay deposit.

Though the clay looks similar to that mined near Saylorsburg, 

Mr. Peck considers that it lies at a higher horizon, and is in Oriskany 

sandstone. The brick formerly made here were buff.

The petrographic character of the clay is little different from 

that of the clay mined at Saylorsburg. For comparison there is 

also given a description of disintegrated Oriskany quartzite, which 

forms the immediate hanging wall.

Disintegrated Oriskany quartzite: Coarse grains of quartz very, 

common; grains of kaolinite scarce; rutile present as inclusions in 

the quartz. There seems to be little material in this rock to yield clay.

Crude clay from bottom of pit: Texture medium. Quartz very 

common, hydromica common, kaolinite very abundant, numerous tiny 

needles of rutile, and a few grains of epidote and tourmaline.

This clay had 16.6 per cent absorption at 1,150° C. and 2.6 per cent 

absorption at 1,300° C.

Washed sample of preceding clay: Texture medium to fine. Quartz 

common, hydromica common, kaolinite abundant, many minute needles of rutile, and a little epidote.

Fire tests of crude clay, Kunkletown, Pa.

Temperature (°C.).

l,150o..............................................................

1,300. ............................................;..................

Absorption 

(per cent).

12.0

0

Porosity 

(per cent).

27.5

0

Color.

Buff.

a Steel hard.
KAOLINS (WHITE RESIDUAL CLAYS). 115

No thin section was made of the burned clay. 

The following tests of the clay from Kunkletown were supplied by 

the Pennsylvania Geological Survey:

Fire tests of clay from Kunkletown, Pa.

Sample No.

1. ............

2.............

3.............

Air shrinkage (per 

cent).

2.84 

2.26 

3.42

Cone 8 (l.sgo4 C.).

Linear fire 

shrinkage 

(per cent).

3.41 

12.42 

11.97

Absorp- 

,tion 

(per cent).

9.7 

0 

0

Color.

Cream....... 

Gray-white. . 

.....do.......

Cone 15 (1,430* C.)-

Linear fire 

shrinkage 

(per cent).

6.57......... 

Overflred.... 

.....do.......

Absorption 

(per cent);

9.2

.8

Color.

Buff.

PETERSBURG, HUNTINGDON COUNTY.

About 300 feet north of Petersburg station (see fig. 16, p. 92) is 

a steep gravity plane that leads up to a clay pit about 500 feet above 

the track. The deposit, which is worked by the Alexandrian Fire 

Clay Co., of Alexandria, Pa., does not contain high-grade material, 

but it is interesting because it occurs at about the same horizon as 

those at Saylorsburg.

The beds strike N. 60° E. and dip 25° SE., and the main face of 

the quarry shows a thick deposit of residual clay overlain by sandstone. The clay is probably derived from the shaly limestone of the 

Shriver formation, the basal formation of the Oriskany group in 

this area, and the sandstone over it is Eidgely sandstone,48 the upper 

formation of the Oriskany group. A sandy shale, which also belongs 

to the Shriver formation, lies between the limestone and the sandstone. There is no white clay here, as at Saylorsburg, and the 

material is all red or black. It is ground before shipment, but the 

uses are not known.

SHIRLEYSBURG, HUNTINGDON COUNTY.

The Kock Hill Clay Co. of Orbisonia, is operating a residual clay 

on the Walker farm 1-| miles southeast of Shirleysburg. (See fig. 

16, p. 92.) There is no doubt regarding the residual character of the 

clay and its close association with the Ridgely sandstone, but some 

doubt has been expressed as to whether the clay underlies or overlies 

the Ridgely.

According to the geologic map of Huntingdon County, published 

by the Pennsylvania Geological Survey, the Oriskany deposits at 

the locality where the mine is operated form a syncline, bordered on

48 Butts, Charles, Geologic section of Blair and Huntingdon counties, central Pennsylvania : Am. Jour. Sci., 4th ser., vol. 46, p. 532, 1918.
116 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

either side by Helderberg limestone, and thus the clay would lie on 

top of the Ridgely, but the west flank of this syncline is also the east 

flank of an anticline, whose crest has been eroded, and the west flank 

of this anticline lies to the west, along the base of the hill.

This theory of the structure seems to be borne out by the dip of 

the rocks. Thus, in leaving the main road south of Shirleysburg and 

ascending the hill toward the mine, there is encountered, first the 

westwardly dipping Oriskany beds, followed by the underlying 

Helderberg limestones, which dip in the same direction. Farther up 

the hill the dips are reversed, and the Ridgely sandstone or upper 

Oriskany is again encountered. This upper outcrop of sandstone is 

then the eastern limb of the anticline and also the western limit of 

the syncline in which the clay appears to lie. The sandstone occurs 

in a tunnel just west of the clay pit but is so fractured that it is 

difficult to determine the dip. Beyond the clay pit to the east the 

Ridgely again outcrops and dips to the east. If the clay, then, lies 

on top of the Oriskany it probably occupies a shallow basin and 

will thin out both to the northeast and to the southwest, as the underlying Oriskany disappears.

The clay itself is derived from a shale, which, if it overlies the 

Oriskany, may be of Marcellus age. In pit No. 2 of the Pennsylvania 

Glass Sand Co. east of Mapleton, the shale overlies and is in contact 

with the Ridgely sandstone of the Oriskany group, but there it shows 

no alteration to residual clay.

The pit has a maximum depth of 15 feet, of which the lower 6 feet 

includes the clay that is being shipped, and the upper 9 feet has been 

stripped off by steam shovel for some distance in advance of the working face. Boring has shown that the clay, in places at least, extends 

17 feet below the present bottom of the pit.

The clay 'is dense, tough, and dark gray when wet but dries out 

almost white. It is very plastic. Some of the clay in the upper 

parts of the bank shows a mottled iron stain due to weathering, and 

parts of the fresh material are rather dark.

Microscopic examination of the gray clay showed the following 

minerals: Quartz not very abundant, hydromica common, kaolinite 

abundant, numerous tiny grains of rutile, and a few grains of zircon. 

In texture the clay is fine and even grained. At 1,150° C. it had 8.35 

per cent absorption and was light buff and steel hard. At 1,300° C. 

it had 0.3 per cent absorption and was brown.

The clay is loaded on motor trucks and hauled to the railroad.

HOLLIDAYSBURG, BLAIR COUNTY.

Residual clay, not a kaolin, is said to be obtained from the Oriskany 

formation, near Hollidaysbiirg, Pa. It is a plastic, siliceous, openburning clay, used to some extent in glass refractories.
KAOLINS (WHITE RESIDUAL CLAYS). 117

WEST VIRGINIA AND VIRGINIA. 

HAMPSHIRE COUNTY, W. VA., AND FREDERICK COUNTY, VA.

White residual clay has been found at several localities in the region 

around Bloomery, Hampshire County, W. Va., and along the southeastern slopes of Great North Mountain, in Frederick County, Va.

The best clay so far discovered in Hampshire County, W>Va., lies 

at the head of Bloomfield Hollow, on the Eaton farm, about 4 miles 

southwest of Cacapon Forks. The clay is probably residual from the 

Romney shale, which here occupies a synclinal trough in the Oriskany 

sandstone. The evidence obtained from borings indicates a considerable body of clay. The clay, which is white or white with mottlings 

of yellow, ranges from fine-texturecl dense material to more sandy 

grades. It would probably have to be washed before shipment to

market.

On the southeastern slope of Great North Mountain, Frederick 

County, Va., about a mile northwest of Mountain Falls post office, 

there is a whitish residual clay, also probably derived from Devonian 

shale. It burns buff and hence is not suited for white-ware bodies. 

Its characters are more like those of a stoneware clay.

LIGNITE, BOTETOURT COUNTY, VA.

At Lignite, Va., there are extensive mines of Oriskany brown ore 

that have been in operation for some years. They belong to the 

Alleghany Ore & Iron Co., and the deposits were opened up first by 

a long cut that followed the outcrop of the ore body. The footwall 

is of limestone and the hanging wall is of Oriskany sandstone. 

Above the sandstone is Devonian shale.

The shale in the cut is no longer fresh but has weathered to a 

whitish clay, whose thickness ranges from 5 to 10 feet and which 

extends quite persistently along the face of the excavation above the 

ore. This whitish clay grades upward into a reddish clay. The 

white clay can be traced for a distance of about 300 feet along the 

face of the cut and has been followed for "a distance of fully 2,000 

feet beyond it.

A churn-drill boring farther down the dip is said to have penetrated the black shale and then the white clay, but the black shale 

does not appear in the face of the cut unless it is represented by the 

red clay.

rxhe white clay is dense and massive and in structure somewhat 

resembles the fire clay at Buena Vista, although, of course, it is of 

later age. Mr. Stull, the manager, states that in places it shows a
118 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

nodular structure, but its composition does not resemble that of 

bauxite. A chemical analysis of the clay gave the following results:

Analysis of residual clay, Lignite, Va.

Silica (SiOa ) ___________________________ 59.17

Alumina (Al20a)__________________________ 24.26

Ferric oxide (Fe2 0s)______________________ 4.62

Lime (CaO)______________________'__ ______

Magnesia (MgO) _______________________ 1.06

Potash (KS0)___________________________ 4.94

Soda (NaaO) ___________________________ .27

Water (H20)___________________________ 5.72

100.04

This clay shows a curious composition because of its high content 

of potash, but this is explained by the microscopic examination of 

the material, which shows abundant hydromica.

The clay worked up with 35 per cent of water to a mass of good 

plasticity which gave 6.1 per cent air shrinkage.

The firing tests resulted as follows:

Fire tests of clay from Lignite, Va.

05 (1,000° C.

03 (1,090° C.

1 (1,150° C.

3 (l,190° C.

5 (1,230° C.

9 (1,310° C.

Cone. Fire 

shrinkage.

5.2

10.6

10.5

10.8

11.3

8.3

Absorption.

11.00

.30

.00

.20

.00

.50

The clay burned buff, but became gray at cone 9. It was steel hard 

at cone 03. It became practically nonporous at cone 03 and remained

so to cone 5, but was overfired at cone 9.

The following tests of this clay were made at the laboratory of 

the Bureau of Mines, Columbus, Ohio.

General physical tests ^of clay from Lignite, Botetourt County, Va.

Workability __________ _____ __ Very plastic, sticky.

Water of plasticity__________________per cent 34.46

Air shrinkage, by volume_______...._______do_, 21.28

Air shrinkage, linear, calculated___________do__ 7. UO 

Modulus of rupture:

Raw clay________._ pounds per square inch_ 122.1 

Mixture of clay and sand in proportion of 1:1_do__ 68.05
KAOLINS (WHITE RESIDUAL CLAYS). 119

Fire teats of clay from Lignite, Botetourt County, Va.

Temperature (°C.).

1,130...........................

1,190.........................;.

1,250...........................

1,310...........................

1,370...........................

Porosity 

(per cent).

0.40

1.70

.00

.00

.90

Color.

.....do.............................

.....do.............................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry clay).

34.60

14.1

34.98

32.61

24.30

Calculated 

linear 

shrinkage 

(per cent).

13.5

5.0

13.3

12.5

8.6

Fusion point, cone 28+. Steel hard at 1,190° C.

This clay hardly deserves to be classed as a high-grade clay, for in 

spite of its white color when unburned it fires to a gray-brown body. 

The bonding strength is low. The clay is overfired at 1,370° C., and

is of low refractoriness, It can be used in stoneware, but would work

better if mixed with a stronger clay.

The following tests of a mixture containing 50 per cent of the clay 

from Lignite and 50 per cent of the white clay from Cold Spring 

(see p. 101) were made in the laboratory of the Bureau of Mines at 

Columbus, Ohio:

General physical tests of mixture of clays from Lignite and Cold Spring, Va.

Workability ___________________Plastic; works well.

Water of plasticity__________________per cent__ 40.43 

Air shrinkage, by volume________________do__ 24.41 

Air shrinkage, linear, calculated___1_______do__ 9. 00 ' 

Modulus of rupture:

Raw clay____________pounds per square inch__ 134. 41 

Mixture of clay and sand in proportion of 1:1,_do__ 60.31

Fire tests of mixture of clays from Lignite and Cold Spring, Va.

Temperature (*C.).

1,190...........................

1,250...........................

1,310...........................

1,370...........................

1,410...........................

Porosity 

(per cent).

0.60

1.04

1.09

.80

.70

Color.

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

37.70

 3Q ru

39.77

vt on

32.10

Linear 

shrinkage, 

calculated 

(percent).

15.0

15.5

15.5

15.5

12.0

Fusion point, cone 28. Steel hard at 1,190° C.

The mixture has a somewhat high air shrinkage, and also fire 

shrinkage, but it burns to a very dense body, which has begun to 

overfire at 1,410° C. The modulus of rupture is not high. The clay 

could be used in stoneware if mixed with a plastic clay of greater
120 HIGH-GEADE CLAYS OF THE EASTERN' UNITED STATES.

strength. The addition of 50 per cent of the white clay to the clay 

from Lignite has not affected its porosity and shrinkage in firing 

very much.

NOTES ON OCCURRENCES OF KAOLIN WEST OF THE MISSISSIPPI.

ARKANSAS.

Bauxihe. Mead,40 in his paper on the bauxite deposits of Arkansas, refers to the kaolinization of syenite and the occurrence of clay 

both under the bauxite and as horses and stringers within it. Indeed, 

he says that the presence of clay in some mines causes 40 per cent oi 

the waste. Some of the analyses of kaolinized syenite which he gives 

show a very low content of ferric oxide, which would indicate that 

there might be valuable refractory clays associated with the ore.

Examination of several of the pits near Bauxite, Ark., in 1918. 

however, showed that there .was no doubt much clay associated with 

the ore, but that most of it is too heavily stained with iron to be 

classed with the grades considered especially in this bulletin. It is 

true that some whitish clays underlie the bauxite in at least some of 

the pits, but the material is in small pockets. Although the clay is of 

no economic value, its microscopic characters are of interest. Practically no quartz was present, and hydromica was rather scarce, but 

kaolinite appeare.d in great abundance, many of the grains showing 

the characteristic " fans" (PL XXVII, A) . There were a few large 

flakes of some pale mica, and a few grains of zircon and rutile were 

noticed.

Little Rock. At the Radcliffe mine of the Republic Mining & 

Manufacturing Co., 5 miles southeast of Little Rock, the following 

section was obtained:

Section at Radcliffe mine, southeast of Little Rock, Arlc.

Feet.

Overburden_______ _ : .. _ 3 

Bauxite, maximum_______ .. ____ 12 

Gray clay_____ Variable.

The clay under the ore is said to be 2 feet thick, but in the woods 

east of the pit the under clay was struck in a number of bore holes, 

and Mr. Watters, the manager, claims that it ranges from 10 to 15 

feet in thickness. It is possibly of refractory character, but its 

physical properties' and the exact extent of the deposit are not known. 

No tests have been made of it. The material could be easily obtained 

if it is of commercial value.

Gray clay is reported in greater quantity around Mabelvale. between Benton and Little Rock. 

. , 

49 Mead, W. ,T., Bauxite deposits of Arkansas : Econ. Geology, vol. 10, p. 28, 1915.
KAOLINS (WHITE RESIDUAL CLAYS). 121

Branner 50 has referred to the occurrence of residual clays in the 

Foilrche Mountain district, near Little Rock. He notes the occurrence of surface exposures in sees. 5 and 9, T. 1 S., R. 12 W., and 

sees. 2, 10, 11, and 12, T. 1 S., R. 13 W., and discoveries in wells in 

sees. 25, 26, 35, and 36, T. 1 N., R. 12 W.

Nothing definite appears to be known regarding the extent of the 

individual deposits, although some of the samples gave promising 

results on firing.

NEVADA. 

By .T. P.-BUWALDA.

The discovery of an abundant supply of white-burning plastic clays 

in the far West would be highly desirable, as some of" the factories 

along the Pacific coast now have to obtain these materials from 

the East. Any occurrences that give any promise of being valuable 

should therefore be recorded.

The United States Geological Survey has received reports, regarding several occurrences in Nevada.

OHEANA.

Pitt-Rowland mine. The Pitt-Rowland mine is on the east slope 

of the Humboldt Range, about 12 miles east of Oreana, Nev., and 

about 24 miles south of Mill City. The road to Oreana is bad and 

has steep grades, but that to Mill City is good and nearly level. 

R. H. Rowland, of Oreana, and W. C. Pitt, of Lovelocks, are the 

owners.

The clay is a white fault gouge, in which perhaps 10 per cent of 

the mass consists of uncrushed fragments of the wall rock, which 

appears to be a bluish-white quartz porphyry or rhyolite. The deposit is sheared by slickensided surfaces, which dip 20° E. and strike 

N. 20° W., and this appears from the underground development 

work also to be the attitude of the clay body. The clay is pure white 

underground, except that it contains bluish-white fragments of solid 

rock and here and there reddish or pinkish streaks caused by cinnabar and by traces of iron. The deposit also includes some largo 

slabs of solid uncrushed rock, which measure several feet in diameter. The property was originally unsuccessfully worked for cinnabar by means of several hundred feet of tunnels and drifts which 

have three openings to the surface. The wall rock was not seen, 

but country rock and uncrushed fragments in the clay appear to be 

rlryolite.

About 300 tons of the clay was shipped in 1917 to California, and 

is said to have been used for blending with other clays, largely im-

&° Bran^er, J, C,, Clays of Arkansas: U, S, Geol, Survey Bull, 351, p. 162, 1908.
122 HIGH-GBADE CLAYS OF THE EASTERN UNITED STATES.

ported. No clay was shipped in 1918. It is said to have been necessary to treat the clay in a tube mill before it could be used; also 

that when the solid fragments were ground up they were as satisfactory for use as the clay itself.

The dimensions of the deposit can not be determined on the 

surface, but the underground workings have exposed a body at least 

200 by 200 by 12 feet, and the actual dimensions are believed to be 

many times these figures. Rough computation indicates tens of thousands of tons of clay in sight underground, and there are several 

thousand tons now on the dumps. The clay would probably have to 

be mined ; not much of it could be dug out of quarry pits. Timbering 

in the tunnels is not required, but where large volumes are removed 

in drifts, the roof needs timbering, as the clay body dips eastward 

into the hill. The openings are 50 to 75 feet above the floor of an 

open canyon. Water is available on the ground.

The samples sent by Mr. Buwalda represent an exceedingly gritty 

coarse-grained clay of low plasticity. Under the microscope it shows 

abundant quartz, sericite, and kaolinite, and a few large grains of 

epidote and some rutile.

The grittiness of the material is well illustrated by its porosity 

after firing, as shown by the tests given below :

Fire tests of kaolin from the vicinity of Oreana, Nev.

Temperature (°C'.).

1,150...................................... . ....

1,300...................................................

Absorption 

(per cent).

30 /

1^0

Porosity 

(percent).

51.1

30.8

Color.

Do.

If this material is to be used in pottery manufacture, it will have 

to be ground, washed, or sifted.

Thin sections of the burned clay were very interesting, for they 

showed a coarse-grained mixture, chiefly of quartz and mica (sericite), the structure of the sericite being well preserved at both the 

temperatures stated.

At 1,150° C. very little of the normal interference color of the 

sericite remains, except in the centers of the grains, where it is somewhat dimmed, and the outer part of each grain shows interference 

colors of kaolinite. At the higher temperature this condition is 

emphasized, and some of the groundmass has become isotropic. In 

Plate XXIX, A (p. 300), there is shown a thin section of this clay 

fired at 1,150° C. as seen with crossed nicols.

LOVELOCKS. °

Adamson-Dichson property. The property of Messrs. A. H. 

Dickson and D. C. Adamson, of Unionville, Nev., is at the mouth of 

New York Canyon, formerly known as Sinclair Canyon, on the west
KAOLINS (WHITE RESIDUAL CLAYS). 123

flank of the East Kange. It is 75 miles southwest of Winnemucca, 

Nov., 34 miles south of Unionville, and 25 miles east by southeast ot 

Lovelocks.

The clay seems to be a sedimentary deposit on a series of Paleozoic 

sandstones and shales, of which series it presumably is a member, and 

the bed is between 75 and 100 feet thick. The clay is white and fairly 

hard in the deposit. It breaks out in rough, angular pieces. At one 

locality in the bed of the creek in New York Canyon the clay much 

resembles putty in its fineness, extreme stickiness, and other physical 

characters, but is pure white.

It is reported that no clay has been shipped. The clay forms a 

stratum 75 to 100 feet thick at or near the surface in a strip at the 

base of the foothills of the range, extending for about 4 miles. 

Though the material is a sedimentary deposit, its clayey nature may 

be due to weathering, and it may therefore be classed as a kaolin. It 

is covered to a shallow depth in some areas by coarse desert waste 

materials, but outcrops abundantly elsewhere, so that it could be 

taken out in vast quantities by surface digging. A tunnel about 50 

feet long has been driven into the clay half a mile northeast of New 

York Canyon.

The thickness of the layer of very sticky, putty-like clay exposed 

in the bed of New York Canyon was not ascertained, as it is exposed 

over an area of only a few square feet. It forms part of the thickness of the clay deposit. .

The road to Lovelocks is good and is nearly level the entire distance 

of 25 miles. Water is present at the clay deposit.

The clay stratum slopes gently westward and northwestward 

toward the valley and away from the East Range, on the edge of the 

foothills of which it lies.

The clay is lean and exceedingly gritty; indeed, under the microscope it looks more like sand than clay. Quartz is very abundant in 

small grains, but kaolinite is also rather abundant and may help to 

give it what little plasticity it possesses. Grains of rutile occur 

sparingly, but stains of limonite are fairly common.

With so much quartz present, the material is naturally very open 

burning, as the following figures indicate:

Fire tests of white clay from area southeast of Lovelocks, Nev.

Temperature (°C.1.

1.150...................................................

1,300...................................................

Absorption 

(per cent).

32.4

28.9

Porosity 

(pp.r cent).

48.9

45.2

Color.

White.

The clay is not steel hard, even at the higher temperature. 

A thin section of the burned clay shows'little change in appearance from the crude-clay, even at the higher temperature, and this
124 HIGH-GRADE CLAYS OF THE 'EASTERN UNITED STATES.

is probably due to the high percentage of sand and to the absence 

of hydromica.

TELLURIDE.

Shepard property. The property of H. S. Shepard is about 9 

miles by road east of Beatty, Nye County, which is the railroad point. 

The deposit lies perhaps 3 miles north of the abandoned camp of 

Telluride in the midst of a relatively flat or gently rolling area on 

the summit of the range next east of Beatty at an elevation of about 

2,000 feet above Beatty.

The property was visited November 26, 1918. The clay outcrops 

over an area about TOO feet long that trends northwestward and is 

about 125 feet wide. Three pits have been sunk in the middle portion of the prospect, each to a depth of about 10 feet, without cutting 

through the clay. There are certainly several thousand tons of the 

material available. The clay is jointed so that it can be quarried out 

in angular masses after blasting. There is practically no overburden 

of waste to be removed.

The clay is very white. It breaks into angular blocks with rough 

surfaces. A few included particles 0.5 to 1 millimeter in diameter 

prove to be euhedral bipyramids of quartz such as are commonty 

found as phenocrysts in quartz porphyries. The clay is of uniform 

character throughout the deposit so far as opened up.

The deposit lies in an area of volcanic rocks, mainly rhyolitic lavas 

and tuffs, and though the relatively flat topography in the immediate 

vicinity does not afford means of determining the relations of the 

deposit, the clay is probably an alteration product of quartz porphyry or of tuff.

Mr. Shepard reports that he shipped one carload of the clay to a 

pottery in California in April, 1918, and that though he was urged 

to ship several additional carloads the price offered was not satisfactory to him, and therefore no further shipments were made.

The deposit was first opened as a cinnabar prospect, but this mineral is not present in paying quantities, although traces of it occur.

No slickensides were seen in the openings in the deposit.

The clay can easily be mined in open pits. A fairly good road extends to Beatty; on leaving the property the road climbs a very 

gentle grade for about 3 miles to a low summit, beyond which it continues with an even downward grade into Beatty.

A physical examination of a sample from this pit showed it to be 

white and somewhat claylike in appearance. It feels very gritty and 

slakes little or not at all in water. Moreover, when ground sufficiently fine to pass through a 20-mesh sieve it yielded a sandy mass 

that was entirely lacking in plasticity when mixed with water. If 

all the material is like this it could not be used as the clayey ingredient of a pottery mixture.
KAOLINS (WHITE RESIDUAL CLAYS). 125

Kiernan property. The property of J. B. Kiernan is on the flanks 

of Bare Mountain, near Telluride, Nev., and 8 miles from Beatty, the 

nearest railroad point. It is near the Bond & Marks clay property. 

The writer could not visit the deposit when at Beatty, late in November, 1918. Mr. Shepard, who aided in the operation of the deposit stated that one car of clay was shipped to a California pottery 

in February, 1917, but the presence of hematite in too large quantity 

resulted in failure to secure further orders. An aerial tram 400 feet 

long was built to convey the material down the steep mountain face 

to the truck road below.

The deposit occurs in an area of limestone and quartzite, but its 

relations are not known to the writer, nor are there dependable 

data at hand regarding its size.

BEATTT.

Bond <& Marks deposit. Beatty was visited late in November, 

1918, but the Bond & Marks deposit could not be examined, according to Mr. H. S. Shepard, who had aided in the operation of the 

Bond & Marks property.

Bond & Marks have shipped four cars to a California pottery the 

last car about June, 1918. No further shipments were made, it is 

said, because of too much hematite in the clay.

The deposit lies near the summit of the mountain, 8 miles southeast of Beatty, Nev. The mountain consists of limestones and 

quartzites. The location of the deposit is high above the valley, on 

a bold mountain face, which renders difficult the task of transporting 

the clay from the deposit to the road below, where it can be loaded 

on trucks or wagons for transport to Beatty.

A specimen of this clay, sent to the United States Geological Survey, was remarkably white and free from grit. It may have been 

an exceptionally fine piece rather than representative of the average 

clay.

Its mineral composition is curious, for under the microscope (PI. 

XXX, A, p. 301) it is seen to consist almost entirely of plates of what 

is probably halloysite and a small amount of kaolinite. There also 

appear to be some very small grains of rutile.

The clay is fairly plastic and very sticky. It burned snow-white 

and to a very porous body, as shown by the following tests:

Fire tests of clwy from Beatty, Nev.

Cone.

1 (1,150° C.).....-.......................................... ........

10 (1,333° C.)o...... .................................... . .........

Absorption 

(per cent).

47 0

19 7

Porosity 

(per cent).

*;Q 9

36.9

Color.

White.

Do.

a Steel hard.

77412 22- -10
126 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Thin sections of the clay after firing showed the following characters :

Clay burned to cone 1 (1,150° C.) : Shows a rather fine fibrous aggregate, with 

a higher index than balsam and a very low interference color.

Clay burned to cone 10 (1,330° C.) : Same as cone 1, but interference colors 

increased.

Clay burned to cone 14 (1,410° C.) : Same as cone 10, but interference colors 

increased still more, and the lighter portions of the section are full of small 

dendritic stains.

If the clay were all as fine and white as the sample sent to the 

Survey, it might be used in paint or paper manufacture.

IDAHO.

Some interesting deposits of white residual clay derived from 

granites and pegmatites occur in Latah County, Idaho, and in neighboring regions. They are said by Soper 51 to have been used in the 

manufacture of fire brick, but possibly if washed they might be useful for much higher grade ware.

CALIFORNIA.

Antioch. The Survey has received samples of a white clay mined 

near Antioch, Calif., but no information is available regarding the 

field relationships of the deposit.

The clay, which is washed before shipment to market, is white 

and suitable for the manufacture of white pottery and tile.

Under the microscope it shows medium to fine texture and a very 

little quartz and hydromica. Kaolinite is very abundant, and some 

of it is exceedingly fine grained. Tourmaline and rutile are only 

sparingly present. The petrographic examination suggests that the 

material may be of an open-burning character, and that it might 

not vitrify at a temperature as low as 1,150° C. Two samples that 

were fired showed an absorption of 33.3 per cent at 1,150° C. and 22.5 

per cent at 1,300° C. The clay was a faint grayish white at the higher 

temperature, and nearly steel hard.

SUMMARY.

The deposits of white residual clay are somewhat widely distributed in the United States, and they occur in probably a greater number of formations than most persons have hitherto imagined.

Only a few of these clays burn white those derived from the pegmatites, the best grade of those from Bollinger County, Mo., and 

some of those from Nevada. The kaolins from Missouri, however,

81 Soper, E. K., Fire clays in northern Idaho: Am. Ceramic Soc. Jour., vol. 1, p. 94, 

1918.
KAOLINS. (WHITE KESIDTJAL CLAYS). 127

contain very finely divided silica, which is difficult to remove in washing, and those from Nevada are so sandy at times that they may 

yield a very low return in washed product. The sample from California is faint cream white when fired.

For paper and paint the color after burning matters not, as the 

material is used in its crude condition.

Practically all the eastern deposits, with the few exceptions noted 

in the preceding pages, are comparatively near to transportation 

routes, and the deposits that are worked ship their product chiefly to 

markets east of the Mississippi Valley.

Bayley has pointed out that in North Carolina there are probably 

large reserves. It may be some time before all the known deposits 

become available, and in addition new deposits may be discovered.

The South Mountain district of Pennsylvania undoubtedly contains reserve supplies, but it is difficult to estimate them.

Little is known regarding the reserve tonnage in the Cambrian 

belt along the west side of the Blue Ridge in Virginia, but this belt 

offers a very promising field for prospecting, as does also the Oriskany 

area of northwestern Virginia and adjoining portions of West Virginia.

The reserve tonnage in southeastern Missouri is uncertain.

In the East, therefore, the most evident reserves are in North 

Carolina and Virginia.

Production has been stimulated by the war, but difficulties with 

labor and transportation interfered with efforts to meet the greater 

demand. However, the decrease in imports did not perhaps benefit 

the miners of residual clay as much as it did those working the sedimentary clays.

KAOLIN MINING AND REFINING.

Kaolin may be mined in three different ways, as follows:

1. By circular shafts. (See PI. II, p. 32.) In this method a 

shaft about 25 feet in diameter is sunk to the bottom of the deposit 

and is lined with cribwork as the sinking proceeds. When all the 

clay is mined out the shaft is filled up and the cribbing removed. 

Another shaft is then sunk near by, and so on until all the clay in the 

deposit has been extracted.

2. By underground mining. A rectangular shaft is sunk, either 

in the clay or in the solid wall rock, and from this shaft levels are 

run off at convenient intervals. . The clay is then stoped out between 

levels. Timbering is usually required to hold up the ground, and 

if the latter is very wet it is likely to cause trouble by'squeezing 

or caving. A modification of this method, which is practiced in the
128 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Mount Holly Springs district in Pennsylvania, consists in running 

a tunnel into the hillside until the good clay is encountered, and then 

stoping it out.

3. By open pits. This method is practiced at a few localities, the 

clay being dug by hand, or in one locality by steam shovel. It is 

very necessary to keep the overburden removed well ahead of the 

clay face to prevent it from washing down over the clay and staining it.

With few exceptions kaolins have to be washed before shipment to 

the market in order to eliminate the sand. The metho.d still prevalent is to disintegrate the clay in water and then run this mixture 

of water and clay through a series of troughs in which the sand settles out, after which the water with the suspended clay passes to 

the settling tank.

An electrolyte like sodium carbonate is sometimes used to deflocculate the clay and to facilitate the settling of the fine sand. Some 

producers use a modification of the troughing system with apparently 

good results, but there is still room for improvement, and the development of a better controllable washing apparatus, which will 

insure more uniform and better results, is highly desired.

More careful oversight of mining and preparation is essential, and 

there should be closer cooperation between the producer and consumer.

The kaolins mined at Cold Spring, Va., and Lutesville, Mo., are 

shipped crude, but neither of these is used primarily for white ware.

RESIDUAL CLAYS OF UNDETERMINED DERIVATION.

ALABAMA.

The writer visited several deposits of residual clay in Alabama 

which should not really be classed as kaolins, for they are not .white 

clays, although one deposit contains some white clay.

Most of these deposits, which are described below, were idle during the summer of 1918.

FORT PAYNE, DEKALB COUNTY.

A deposit that appears to be a residual clay derived from Cambrian 

rocks has been opened by F. E. Ladd about 4 miles north of Fort 

Payne, just north of the Gibson Gap road. The exact shape and 

extent of the deposit are not known, but a cut about 200 feet long, 20 

feet in greatest depth, and about 50 feet in greatest width has been 

excavated. The overburden consists of 3 to 4 feet of ferruginous 

cherty clay. The land rises slightly to the west, and the overburden 

increases somewhat in this direction.
RESIDUAL CLAYS OF UNDETERMINED DERIVATION. 129

Mr. Ladd states that a shaft sunk 200 feet west of the pit struck the 

clay, and that a boring in the bottom of the large pit showed 28 feet 

more of clay. Similar clay occurs in a valley about three-fourths of 

a mile north of Mr. Ladd's pit, but no clay was found on the south 

side of the Gibson Gap road.

The clay is gray, though it contains a few yellowish mottlings, and 

very tough but gritty.

Under the microscope quartz is seen to be fairly common, and 

hydromica and kaolinite abundant. Eutile is present in numerous 

tiny grains, and there is a little tourmaline.

A chemical analysis of the clay was supplied by Mr. Ladd, as 

follows:

Analysis of fire clay from pit of F. E. Ladd, Fort Payne, Ala.

Silica (Si02 ) _____________ 60.26

Alumina (A12OS )_________________________ 28.56

Ferric oxide (Fe2O3 )________-__________"__ .49

Lime (CaO)___________________________ .60

Magnesia (MgO)_________________________ .07

Soda (Na20)___________________________ .54

Loss on ignition^________________________ 10.15

100.67

The clay is very smooth and plastic and burns steel hard at 1,150° 

C. The porosity at this temperature is 25.6 per cent and the color 

cream white. At 1,300° C. the porosity is 15.5 per cent and the color 

light buff.

A thin section of the clay which was burned at 1,150° C. formed a 

compact body, with a groundmass that showed low interference 

colors and some isotropic material. The appearance of the clay 

burned at 1,300° C. was similar, except that the number of isotropic 

grains had somewhat increased.

The clay has been used for making fire bricks at Fort Payne, and 

some of it has been shipped to Pennsylvania for use in glass-pot 

mixtures.

There is a good road for hauling the clay to Fort Payne, but the 

line of the Southern Railway is not more than 1-J miles from the pit.

Another opening has been made in the hill slope about 8 miles 

north of Fort Payne and 3 miles west of Alien's switch. This pit. 

which is operated by the Consolidated Mining Co'., is worked mainly 

for bauxite. Associated with the bauxite in irregular masses is a 

gray and grayish-brown clay. The visible quantity is not very large, 

and it could be worked only in connection with the bauxite. It has 

not been used up to the present time*
130 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

BYNUM, CALHOUN COUNTY.

A curious deposit of clay that is residual, derived apparently from 

schistose rocks, has been opened on the Pope farm, 3 miles west of 

Bynum, on the south side of the Alabama Great Southern Railroad. 

The material has been worked by means of an open pit and shaft, 

which were idle and partly filled with water at the time of the 

writer's visit.

The walls of the pit consist of gray and ferruginous sandy residual 

clay, but in this clay there occur lenslike masses of a whitish and 

a black clay, which are the materials sought.

The whitish clay is fairly dense, but the black clay ranges from 

dense material not unlike the Klingenberg clay in appearance to 

light porous, clay. The black color is evidently due to carbonaceous 

matter. These clays have been used in crucible mixtures.

Under the microscope the black clay appears to be very fine grained. 

It shows no quartz, but hydromica is fairly common, and -grains of 

rutile are fairly numerous. There are a few small grains of zircon 

and a very few of chlorite. The rest of the material consists of exceedingly small, deeply stained particles of indeterminate character, 

which may be colloidal matter.

The white clay is fine to medium grained. It shows abundant 

hydromica, which is commonly coagulated, and abundant kaolinite, 

which exhibits a few fans and vermiculites. Grains of rutile are 

present and a very little tourmaline.

The following tests of the black clay were made at the laboratory 

of the Bureau of Mines in Columbus, Ohio:

Tests of black clay from Bynum, Ala.

Character of raw clay__________Stuffy; low specific gravity. 

Workability____________________-Very plastic, sticky.

Drying quality ' _ _ ______________Good.

Water of plasticity- _____________:___per cent 48. 60

Air shrinkage by volume_________________do__ 18. 24 

Air shrinkage, linear, calculated____________do__ 6.6 

 Modulus of rupture________. pounds per square inch__ 136. 5

Fire tests of black clay from Bynum, Ala.

Temperature (°C.).

1.190...........................

1,250...........................

1,310...........................

1,370...........................

1,410...........................

Porosity 

(per cent).

33.9

33.45

16.70

7.40

2.40

Color.

.....do............................

.....do............................

.....do................ ...... ...

Volume

shrinkage

(per cent 

in terms

of volume

of dry clay).

38.50

41 ^8

en 70

54.50

56.70

Calculated

linear

shrinkage 

(per cent

in terms of

dry clay).

15.0

16.4

20.9

23.1

24 3
RESIDUAL CLAYS OF UNDETERMINED DERIVATION. 131

Deformation temperature, cone 34 (1,810° C.). Steel hard at 1,250° C. Develops small cracks in firing.

This clay shows excellent refractoriness and burns sufficiently white 

for the manufacture of pottery. Its shrinkage is not excessive, but 

it shows low strength in the unfired condition. It could be used as 

an ingredient of mixture for making pottery and other products that 

require a refractory, white-burning, open-textured clay.

CLATTS OF CARBONIFEROUS AGE (CHIEFLY SEDIMENTARY).

The abundant supplies of refractory clay in the Carboniferous rocks 

have long been known, and this clay is utilized at many localities 

for the manufacture of refractory wares.

Few of these localities need be mentioned here, as most of them 

are not significant in the present discussion. The chief deposits described in this bulletin are those of value to manufacturers of glass 

refractories, especially the deposits of the St. Louis district and 

southern Ohio. In addition the high-alumina clays of central Missouri and the indianaite deposits of Huron County, Ind., are considered.

ST. LOUIS DISTRICT, MO.

The area around St. Louis has long been an important center of the 

refractories industry, which has been built up on the local clay 

deposits.52

All the fire clay in this district is obtained from a single bed, 

known as the Cheltenham fire clay, which stratigraphically lies near 

the base of the Pennsylvanian series of that region. It was deposited 

in upper Pottsville time.

The thickness of this bed ranges from 1 to 21 feet, but where 

worked it is commonly from 3 to 8 feet, and in some of the areas 

where the thickness exceeds 8 feet only the best portion of the bed is 

mined. .The roof is a micaceous sandstone, and the floor is commonly 

pyritiferous sand. In some of the mines the floor shows rolls, which 

may rise to such an extent as completely to pinch out the clay.

The Cheltenham clay is hard or shaly, and usually gray. It may 

differ from point to point in the district, and there may also be a 

variation from the top to the bottom of the bed. It is therefore not 

uncommon to sort the material. Fenneman states that in the western 

part of the field the lowest clay in the bed is the best; in Cheltenham 

the middle clay is the best; and in the southern part of the field the

M Wheeler, H. A., Clay deposits: Missouri Geol. Survey, vol. 11, 1897. 

Fenneman, N. M., Geology and mineral resources of the St. Louis quadrangle, Mo.-Ill.: 

U. S. 'Geol. Survey Bull. 438, 1911.
132 HIGH-GBADE CLAYS OF THE EASTERN UNITED STATES.

top clay is the best. Although most of the Cheltenham clay is used 

in the manufacture of fire brick, the better grades have a wide reputation because of their value in the manufacture of glass pots, zinc 

retorts, and graphite crucibles.

The pot clay, then, which is not found in all the mines, represents 

the best-grade material. After mining it is piled up^on the surface 

and allowed to weather for at least a year, and some of it for two 

years. It is then put through a washing process, not so much to 

remove the fine sand as the coarser impurities, consisting of concretions and lumps of pyrite.

The growth of the city of St. Louis has interfered with the working out of all the clay reserves of the district. The bed has been 

mined, however, at several somewhat widely separated points, as 

south of Clayton, at Castello, 9 miles northwest of Cheltenham, and 

north of Baden. Therefore, further prospecting may reveal its presence in other localities.

The firms that reported production of glass-pot clays in 1917 were 

F. E. Bausch, G. J. Berresheim. Cheltenham Fire Clay Co., Grand 

View Fire Clay Works, Highland Fire Clay Co., Laclede-Christy 

Clay Products Co., and Walsh Fire Clay Co.

The variation in the character of the clay is shown by the following tests, given by Bleininger.53

Physical tests of Cheltenham fire clay, St. Louis, Mo.

£ .

o S

 M

ll

3 S

WH

o'3

13

4

6

14

16

27

2DO s

I"3

1

S

3

1

&

31.14 

43.63

34.66

29.54

25.52

0

to11

2 <D as? ~-a

°'H

"ca

«

.57 

.72

.54

"."74"

.g

o> o5

f °

£ &So"3

C8 H

Is

eo

38.42 

43.63

42.63

37.02

28.52

i

to

1S

52 

33

117

26

46

"Sis a 2

73 &

3 PIf"o o

«3 .

Ill

838 

328

990

575

489

|;| d d_g

O W 03 §-s

ftc?"

O oj" w

a 3 d

1-1 "SIS§

S

399 

351

554

351

263

|

1'C

1?-S^

S,

^

1,290 

1,200

 1,200

1,400

ttt

 g

<gi_

°d 

£» ^^

g

S, 

1

1,320 

1,430

1,320

1,320

1,425

o 

o

1Pi

 I

"3

27 

32

27

""si"

Eemarks.

No difficulty in drying. Not a h i ghgrade bond clay. 

Very fat but dries well. Promising

as a crucible material.

Excellent plasticity; dries well; not 

suited for steel-melting crucibles

or glass refractories. Should be

useful for brass-melting work. 

Good plasticity; dries well.

Good plasticity; dries well. Vitrification proceeds steadily to 1,400° 

C. Burns satisfactorily. Somewhat deficient in bonding power.

68 Bleininger, A. V., and Loomis, G. A., The properties of some American bond clay a: 

Am. Ceramic Soc. Trans., vol. 19, p. 601, 1917.
RESIDUAL CLAYS OF UNDETERMINED DERIVATION. 133

A microscopic examination has not shown much, especially as we 

have no burned samples by which to check it. However, the data»at 

hand are shown in the following table:

Minerals in Cheltenham fire clay.

WaAd pot clay.

Weathered pot 

clay (another 

firm).

 Fire-brick clay.

Selected crude 

clay.

Washed pot clay 

(another firm).

Quartz.

Common.

Common.

Common.

Common.

Some.

Hydromica.

Abundant.

Abundant.

Abundant.

Abundant.

Abundant.

Kaolinite.

Abundant.

Common.

Scarce.

Scarce.

Common.

Kutile.

Few small 

grains.

Common.

One grain.

Scarce.

Common.

Epidote.

One or 

two 

grains.

Zircon.

One or 

two 

grains.

Tourmaline.

Several 

grains.

Titanite.

Two or 

three 

grains.

The main fact brought out in the table is that in the washed pot 

clay the hydromica and kaolinite are more abundant than in the 

other grades. The minor minerals are of no special significance.

GLASS-POT CLAYS IN OHIO. 

By WrLBim STOUT.

In the Portsmouth district, Ohio, clay for glass pots is regularly 

prepared by only one firm, the Harbison-Walker Refractories Co.

The clay used is the Lower Kittanning or No. 5, which underlies 

the Lower Kittanning coal.

The section at the mine, which is in Spencer Hollow, sec. 3, Washington Township, Lawrence County, is as follows:

Section at Spencer Holloio, Lawrence County, Ohio.

Ft. in.

Shale and sandstone_______________________ 12 

Clay, in part flinty (Oak Hill)________________ 4 6 

Coal __________________________ 10

Clay (Lower Kittanning)___.__________________________

Coal___________________________________________

Clay, dark, ferruginous, usually excluded (Lower Kittanning) ____________:___; ___________________

Clay, plastic, light (glass-pot clay)"____^___________ 5

Clay, light, plastic, siliceous__________________ 2 

Sandstone, clay bonded____________________ 2
134 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The clay is mined both by stripping and by drifting. The portion 

generally preferred is that near but not on the outcrop, under about 

5 to 15 feet of covering, where the overlying coal is partly or even 

badly weathered.

The clay averages about 6 feet in thickness but may range from 4 

to 12 feet.

The clay bed is generally divided into two parts, the lower siliceous, 

and the upper, which commonly ranges in thickness from 2 to 4 feet, 

quite free from siliceous matter and very plastic.

About 4 inches of the clay just beneath the coal is generally ferruginous, and this material must be thrown out in mining.

,The quantity of clay available for glass refractories in eastern 

Scioto, southern Jackson, and western and northern Lawrence counties is very large, as the bed is persistent over several townships and 

maintains both its thickness and its quality.

The clay from the Spencer Hollow mine is shipped to the company's 

mill on Frederick Creek, near Scioto Furnace, Scioto County, where 

it is prepared for the market.

Clay in the crude form or ground only in the dry pan is also shipped 

by Morgan & Horton, of Eifert, Scioto County, but not much of this 

is used by the glass-pot trade.

The Federal Clay Products Co., at Mineral City, Tuscarawas 

County, has been furnishing calcined clay from the Lower Kittanning 

bed to the glass-pot trade. The company also manufactures blocks, 

floats, and other articles for the industry.

The section at the mine includes the following beds:

Section in mine of Federal Clay Products Co. at Mineral City, Ohio.

Ft. in.

Coal (Lower Kittanning)___________________ 3 6 

Clay, plastic, impure, not used______:________ 5 

Clay,flint,used for glass-pot trade (LowerKittanning). 3 6 

Clay, plastic, used for bonding________________ 5 

Sandstone.

Bleininger and Loomis 54 give the following tests of some refractory bond clays from southern Ohio. No. 1 is not regarded as the 

highest type but is considered to be useful in a mixture with other 

clays; No. 2 is somewhat similar; and No. 3, a washed clay, is regarded as useful for bonding in a mixture for steel-melting crucibles 

and glass refractories.

M Bleininger, A. V., and Loomis, G. A., Properties of some American bond clays: Am. 

Ceramic Soc. Trans., vol. 19, p. 601, 1917.
RESIDUAL CLAYS OF UNDETERMINED DERIVATION. 

Physical tests of refractory lond clays from Ohio.

135

1 2 3

Water of plasticity ............-----------------.-.--.----..-.- -tier t

Ratio of pore water to shrinkag 

Shrinkage by volume in terms

Modulus of rupture of dried claj 

Modulus of rupture of 1 part of 

Fusion cone

of dry volume. ................. .per c 

. . . . ........----- --.mini

f. ...........---- -Bounds

clay to 1 part of sand

per square i 

.......... dc

ent.. 22

ent.. 24 

ites.. 

ach.. 

>.....

Temperature (° C.).

1,050..........................

1,075..........................

1,100..........................

1,125..........................

1,150..........................

1,175............. ...... ..

1,200..........................

1,230..........................

1,260 .........................

1,290..........................

1,320..........................

1,350..........................

1,400..........................

1,425........................?.

1,450..........................

1

Porosity 

(per cent).

22.83 

18.91 

15.82 

14.35 

12.95 

12.02 

11.56 

8.66 

8.71 

6.82 

2.50 

.52 

4.56 

6.01 

5.60

Volume 

shrinkage.

7.34 

10.10 

12.85 

14.87 

16.06 

17.15 

17.10 

17.38 

17.80 

18.06 

18.18 

13.78 

14.21 

9.08

2

Porosity 

(per cent).

23.55 

21.72 

17.61 

15.01 

12.05 

10.26 

9.71 

6.90 

3.14 

.49 

.09 

2.83

Volume 

shrinkage.

6.66 

9.97 

11.95 

15.61 

17.95 

18.21 

19.78 

20.83 

21.69 

21.80 

20.65 

16.20

08 25.30 26.84 

80 .83 .72 

46 27. 92 26. 98 

8 81 10 

i79 452 328 

281 309 227 

31 301 311

3

Porosity 

(per cent).

25.42 

22.43 

19.15 

16.76 

16.38 

16.20 

14.50 

12.22 

7.25 

.19 

.71 

1.46 

3.56

Volume 

shrinkage.

7.08 

11.02 

14.50 

16.30 

17.12 

18.25 

20.20 

22.08 

25.12 

26.02 

21.60 

26.32 

25.41

Overflred.

PENNSYLVANIA.

Some of the semiplastic clays of Pennsylvania have been used 

from time to time in tank blocks. Flint clay from the lower Mercer 

bed is obtained at Dean, Cambria County, Pa. It is used for tank 

blocks and pots. Clay for pots and blocks is also obtained at Huefner and Lucinda, Clarion County.

FLINT CLAYS OF CENTRAL MISSOURI. 

OCCURRENCE AND DISTRIBUTION.

Wheeler 55 in 1897 called attention to a remarkable series of deposits of flint clay in Missouri that are unlike any others found in 

the United States. These deposits occur in the central part of the 

State, more particularly in the east-central district, of which Gasconade County is the center..

Wheeler also notes that they are abundant in Warren and Montgomery counties, along the Wabash Railway, in Callaway County, 

and also in Osage, Franklin, Crawford, and Phelps counties.

Other known deposits extend the area as far north as Monroe 

County, as far west as Morgan and St. Clair counties, and as far 

south as Dent County.

"Wheeler, H. A., Clay deposits of Missouri: Missouri Geol. Survey, vol. 11, p. 201, 

1897.
136 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Wheeler states that the deposits are not confined to any particular 

geologic formation but occur in Cambrian, Ordovician, and Silurian 

rocks. He says that they are invariably basin-shaped and occupy 

sink holes in limestone. The basins are from 50 to 200 feet in diameter and 15 to 50 feet' in depth. Generally a sheet of sandstone several feet in thickness lies between the limestone wall of the basin 

and the flint clay. He comments on their irregularly jointed structure and massive character, which, he says, in a few places suggest a 

water-laid deposit.

The following analyses, taken from Wheeler's report, give some 

idea of the composition of the flint clays:

Analyses of flint clays from Missouri.

Silica (SiOj). .............................................................

Alumina (A1»O3) .........................................................

Water (HjO).. ...........................................................

Ferric oxide (Fes03 ). . ....................................................

Lime (CaO)... ...........................................................

Magnesia (MgO).. . .......................................................

Alkalies (NajO.KjO). .................................................. .

1

45.12

40.46

13.34

.47

.29

.Trace.

J .30

99.98

2

44.70

35.90

12.20

3.35

3.00

.21

.29

99.65

3

40.50

43.22

14.15

.31

1.11

Trace.

.51

99.80

1. High Hill, Montgomery County.

2. Owensville, Gasconade County.

3. Drake, Gasconade County. ,

Some of these clays show an abnormally high percentage of 

alumina, exceeding even the flint clays of Kentucky,56 which have 

been shown by Galpin 57 to contain gibbsite.

Wheeler comments on their high content of alumina, as much as 

44 per cent, as well as on the contamination by red iron oxide in many 

places.

The writer had occasion to visit a number of these deposits in 

the summer of 1918 and found that several interesting developments 

had taken place since Wheeler had examined them.

The deposits visited are in Crawford and Gasconade counties 

(fig. 18), most of them along the line of the Chicago, Rock Island & 

Pacific Railway or near it.

All the deposits examined appeared to lie in the Pennsylvania 

sandstone, and none of the pits seen showed any limestone in their 

walls or in the vicinity. They show no uniformity in elevation, for 

some of .them occur on high ground and some in depressions.

M Greaves-Walker, A. F., Note on a high-alumina flint clay: Am. Ceramic Soc. Trans., 

vol. 8, p. 297, 1906.

w Galpin, S. L., Studies of flint clays and their associates: Am. Ceramic Soc. Trans., 

vol. 14, p. 301, 1912.
RESIDUAL CLAYS OF UNDETERMINED DERIVATION. 137

A good opportunity to determine the stratigraphic relationships of 

these clays "in the area visited was found near Bland. Here the 

clay pit of Campbell & Lichte lies near the top of a broad ridge. 

Along this ridge a short distance northwest of the town the Pennsylvania" sandstone shows in its lower portion a breccia that contains 

angular fragments of the " cotton rock " and chert of the underlying 

Jefferson City limestone, which crops out farther down the hill. 

Still farther down below this bed is the Roubideau formation.

All the deposits of flint clay that were visited occupied cavities 

in the sandstone which appear to be of irregular shape, and some

FIGURE 18. Map showing flint-clay pits in central Missouri.

1. Cox's pit.

2. Sassman pit.

3. Connell pit.

4. Charles Brown pit.

5. Heidel & Toelke pit.

6. Bauer & Watklns pit.

7. Haynes pit.

8. Hensley pit.

9. Baxter pit. 

LO. Helm pit.

11. Lacey pit.

12. Dittmanpit.

13. Myers pit.

14. 15. Campbell & Lichte pit.

16. Travis pit.

17. Pointer pit.

18. Jackson pit.

have a depth of not less than 50 feet. In only one, the Sassman pit, 

at Owensville, was the country rock found near the quarry, and 

there it was sandstone. The walls of the pits where they were exposed consist of sandstone, whose surface in some places dips under 

the flint clay, but in other places overhangs it. In the pit at Hofflin 

the sandstone contains angular fragments of the flint clay.

Two samples of this sandstone were examined under the microscope. One of these samples, from Cox's pit near Hofflin, was made 

up entirely of grains of quartz embedded in a little clay cement.
138 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The quartz contained little prisms of an indeterminable mineral and 

a few cavities that were partly filled with liquid. A second sample, 

from the south side of Connell's pit, at Owensville, showed abundant 

quartz in rounded grains embedded in a matrix that consisted chiefly 

of kaolinite. Grains of diaspore were very scarce. Rutile was 

present, both as inclusions in the quartz and in the matrix. A few 

grains of tourmaline and zircon were seen.

Mr. H. T. Darlington, of Natrona, Pa., says that in some places a 

granular rock that is associated with the flint clay and that is full of 

grains of diaspore is easily mistaken for the quartz rock.

CHARACTER OF THE CLAYS.

The flint clay is buff to gray, massive, and fine grained. It has 

conchoidal fracture and a hardness of about 2.

Under the microscope the clay is found to be exceedingly fine 

grained; indeed some of' the smallest indeterminable particles may 

be colloidal, although others show interference colors.

Among the identifiable grains in the samples examined kaolinite 

was noted and in places was very abundant; hydromica was present 

in different amounts in different samples; diaspore was common in 

one sample, but scarce in another, in which it occurred in fine grains; 

rutile was invariably present, but not in the same amounts; zircon 

and tourmaline were rare.

Organic material appears to be rare. In one pit near Bland it 

occurred in a finely divided condition associated with small fragments of stems and leaves. In Heidel & Toelke's pit at Rosebud a 

thin bed of impure coal occurs in the clay.

Sassman's pit, at Owensville, and Heidel «fe Toelke's pit, at Rosebud, are the only pits where the flint clay shows any stratification,

but it is fractured by numerous joint planes which show no regularity, and it exhibits stains along these joints^.

In some pits the flint clay is slightly softer than usual, but still 

retains its other features. In others there is a soft plastic, in places 

whitish clay associated with the flint near the edge of the deposit, 

which probably represents a weathered form of the flinty material.

In several of the pits red or red and white mottled clay is associated with the flint. In Cox & Sassman's pit, near Owensville, the 

mottled clay forms a distinct bed overlying the flint clay, but in 

Heidel & Toelke's pit, near Rosebud, the relations are not as clear, 

although they may be similar. This variegated clay is exceedingly 

fine grained; indeed, under the microscope most of the grains appear to be isotropic, suggesting that they may be colloidal. Some 

hydromica and kaolinite are recognizable. Aside from the hematite coloring on the grains, the red and white bands or portions show 

no difference,
RESIDUAL CLAYS OF UNDETERMINED DERIVATION. 139

The most remarkable material in these flint clay deposits is a hard 

dolitic clay, which is called "rough clay" by the workmen. This 

material in places is harder than the flint clay and consists of small 

rounded bodies or oolites, the largest of which are one-sixteenth or 

three thirty-seconds inch in diameter, embedded in a fine-grained 

groundmass. This clay is gray, brown, or buff in color, and though 

generally compact it shows in places a slightly pitted structure. It 

is not present in every deposit, and, though it does not occupy any 

definite position, it occurs in most places in the middle or near the 

top. The masses of it are of irregular shape and differ in size, and 

there is usually a gradation from the oolitic clay into the normal 

flint clay'. In at least one pit there are two distinct types of oolitic 

clay, which form more or less distinct beds.

This oolitic clay does not appear to have been known when Wheeler 

prepared his report, but it is a valuable product of the flint-clay district at the present time. Its value lies chiefly in its high percentage 

of alumina, which is due to the presence of the mineral diaspore 

(AlaO3.H2 0). Although diaspore may be present in the finergrained normal flint clays it is .probably confined chiefly to the oolitic 

clays.

Under the microscope the grains of diaspore are easily recognized. 

They are abundant, although they vary in texture; some are very 

fine, but others are much coarser.

Sections through the oolites examined under the microscope show 

that some of them consist of a mixture of grains of diaspore stained 

with iron oxide, through which extend streaks or circles of clear 

grains of diaspore. (See PI. XXVIII, A.)

The grains of diaspore are commonly associated with abundant 

kaolinite, but hydromica, on the other hand, is generally rare.

The following partial analyses of diaspore clay have been supplied by M. H. Thornberry, of the experiment station of the University of Missouri.

Partial analyses of flint clay from Missouri.

Silica (SiOj)....... .............

1

11.50

74,03

.97

13.20

2 

18.84

62.69

1.21

13.77

3

10.15

72.87

.84

14.95

4

6.24

68.02

12.48

13.10

5

3.60

81.68

1.32

13.72

6

1.68

68.96

9.28

13.77

7

13.54

71.83

1.21

12.71

Mr. Thornberry states that in several analyses which he has seen, 

in which titanium oxide was determined, this constituent amounted 

to about 3 per cent.

In the petrographic descriptions of these clays the presence of 

rutile is noted. Analysis No. 5, above, approaches somewhat closely
140 HIGH-GBADB CLAYS OF THE EASTERN UNITED STATES.

to the theoretic composition of diaspore, which has 85 per cent 

alumina and 15 per cent water.

No definite name has been suggested for this high-alumina clay. 

It is not an ordinary flint clay, and hence that name does not apply. 

Mr. H. T. Darlington, of Natrona, Pa., has suggested the name of 

jehyte, formed by the initial letters of J. E. Hutchinson, who called 

it to his attention. It seems to the writer, however, that diaspore 

clay would be a better name to use.

GRADES OF CLAY SHIPPED.

The grades of clay shipped from the district visited consist of hard 

flint clay, diaspore clay, and plastic clay.

The first clay is used in part for refractory materials and in part 

as a filler in certain manufactured products not classed as ceramic 

wares, for which, so far as known, some of the semihard flint clay is 

also used.

The diaspore clay is of value in the manufacture of refractories; 

in fact, it might be used as a substitute for bauxite. It can not be 

used alone, or at least without previous calcination, as its fire shrinkage is too high.

The plastic clay, which appears to be weathered flint clay, is sold 

to manufacturers of fire brick and also to manufacturers of rubber 

goods for a filler. «

FUTURE OF THE DISTRICT.

It is somewhat difficult to predict the future of the district, but it 

seems safe to say that there will be a demand for the materials obtained from the clay pits as long as the supply lasts. The deposits 

appear to differ in size and to be liberally but irregulafly distributed 

over the country. They do not occur at any uniform elevation, for 

some of them are on ridges and others are in depressions. Individual 

mining operations are usually small, and many of the pits are worked 

on a royalty basis. The farmer on whose land they are opened commonly does the digging. The actual amount of diaspore clay in sight 

in the pits visited was not large, but new deposits are continually 

being opened.

DETAILS OF THE FLINT-CLAY PITS. 

HOFFLIN, CRAWFOKD COUNTY.

A pit on the land of Dr. Cox, three-fourths of a mile northwest of 

Hofflin station, is about 50 feet in diameter and about 20 feet deep in 

the center. (See PL VII, A.)

Sandstone forms the southerly dipping, hanging wall on the south 

side, but the other walls show flint clay at most points, and the
BESIDITAL CLAYS OF UNDETERMINED DERIVATION., 141

boundary of the deposit does not appear to have been reached. Sandstone is said to underlie the flint clay but was not visible.

On the north side of the pit, but practically in the center of the 

deposit, there is a mass of oolitic diaspore clay which extends to the 

surface. As exposed, the mass was about 10 feet maximum depth, 

30 feet long and 25 feet wide. It was surrounded on all sides by flint 

clay.

The flint clay is fine grained, buff, and fairly hard. It has two sets 

of steeply dipping joints, and the joint planes in places show iron 

stains.

Most of it is smooth but in places it shows an oolite. A microscopic 

examination of the clay reveals its very fine grain, some of the partiFIGURE 19. Plan of Connell flint-clay pit, Owensville, Mo. 

For section along line A-B see figure 20.

cles being too small for identification and apparently of an isotropic 

nature. Kaolinite is in places rather abundant, but hydromica is. 

scarce. A little fine-grained diaspore is present. Tourmaline and 

zircon are very scarce, but tiny needles of rutile are numerous.

The diaspore clay grades into the flint, and about 2£ carloads of it 

have been taken from this pit.

The country rock is sandstone.

OWENSVILLE, GASCONADE COUNTY.

Cormell pit. The largest pit near Owensville is operated by Mr. 

J. P. Connell and is about a quarter of a mile west of the town. The 

pit is an irregular opening (fig. 19) whose largest diameter is about 

500 feet, and the product is mostly flint clay of the usual structure 

and texture. The best grade is gray and contains a few oolites. 

77412 22- 11
142 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Diaspore olay was seen only in small amounts and is of irregular 

occurrence. In places around the edge of the deposits there are 

masses of a softer semiplastic clay.

Sandstone occurs around the deposit and is exposed in some of the 

walls, but the boundary between it and the clay is irregular. Thus 

at one point in the west side of the pit the clay dips under it, but in 

the southwest side it projects outward into the deposit and is surrounded by clay on three sides. (See fig. 20.)

I am informed by Mr. H. T. Darlington, of Natrona, Pa., that 

above this sandrock lies one of similar texture and appearance, 

which contains grains of diaspore instead of quartz, and that on 

sight the one is likely to be mistaken for the other.

A thin section of the flint clay showed it to be very fine grained 

and to consist of a mixture of kaolinite, hydromica, and diaspore, 

together with a few tiny needles of rutile. Scattered through it 

were some small oolites made up of coarser grains of diaspore.

Another thin section of the flint clay, which contained more 

oolites than the one just mentioned, showed a fine-grained aggregate

of abundant diaspore and 

kaolinite, together with a 

few grains of rutile and 

zircon. The oolites in the 

fine-grained groundmass 

are composed of diaspore 

that is more coarsely crystalline than the rest, but

FIGURE 20. Section along line A-B in plan of some of ft |s cjear an(J

Connell flint-clay pit (fig. 19). a, Residual . .

soil with chert; 6, soft clay; c, clayey sand- SOHIC 01 it IS stained With

stone; il, flint clay. jron oxi<le.

Two samples of the clay that were examined contained abundant 

oolites in a fine-grained groundmass. Both samples showed considerable material that may be colloidal. Diaspore and kaolinite 

were common in one, but both together with hydromica were rather 

scarce in the other, except in the oolites, which showed much diaspore. 

Grains of rutile, titanite, and epidote were noticed. 

, About 70,000 tons have been shipped from this deposit.

Sassman pit. Mr. C. C. Sassman has a small pit just northwest 

of Owensville. The excavation, which trends north and south, is 

about 130 feet long and 25 feet deep. The east face shows a pronounced synclinal structure, indicating that the clay was deposited 

in a basin. (See fig. 21 and PI. VII, B.)

In the center of the section, below the overburden, which is 4 to 5 

feet thick, there is a bed of red and white mottled clay, about 12 

feet thick, and this is underlain by 8 feet of flint clay, which Mr. 

Sassman states has been proved to a depth of 20 feet below the 

bottom of the pit.
RESIDUAL CLAYS OF UNDETERMINED DERIVATION. 143

The mottled clay consists chiefly of red and white patches indiscriminately mixed, but some of it shows thin alternating red and 

white bands.

Under the microscope this material is found to be extremely fine 

grained and much of it isotropic, possibly colloidal. Kaolinite and 

hydromica are only sparingly recognizable. The only difference 

between the red and white material to be seen under the microscope 

is that the red grains are stained with hematite and the white are not.

The flint clay shows the usual texture and structure but not the 

usual hardness, and at the south end it grades upward into a whitish 

plastic clay. Diaspore clay occurs in the flint in a few small, irregular masses, but none was visible at the time of the writer's visit 

except a small patch on the west wall of the excavation, and this was 

not high grade. Whenever any good diaspore clay is found, it is 

put in a separate pile until enough has accumulated for shipment.

It is probable that the excavation marks almost the limit of the 

deposit from north to south, for sandstone occurs a little beyond

aatlc 

clay ,

'Concealed

Bottom of .pit

50 Feet

FIGURE 21. Section in Sassman flint-clay pit, Owensvllle, Mo.

the south wall, and 50 feet northwest of the pit there is an outcrop of 

a massive fine-grained sandstone, which seems to dip gently toward 

the excavation.

The clay, however, extends probably 300 feet west of the excavation, and soft, oolitic clay lies close to the surface about 100 feet 

west of the opening.

Under the microscope the flint clay is found to be composed of exceedingly fine grains, mostly indeterminate, although a few grains 

of kaolinite are recognizable. There are numerous tiny grains of 

rutile.

The low-grade diaspore clay on the west side of the. pit is harder 

than the flint clay. It shows abundant kaolinite, and diaspore is 

fairly common but very fine grained. There are some small oolites 

of coarser grains of diaspore. Rutile is very abundant but occurs 

mostly in tiny grains. There are also one or two grains of tourmaline and quartz.

The flint clay is the chief product of the pit, although the rough 

clay is marketed when enough has accumulated. Some white plastic 

clay has also been shipped. The mottled clay is thrown on the dump.
144 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

ROSEBUD, GASCONADE COUNTY.

Brown pit. A small excavation on land belonging to Mr. Charles 

Brown, about 2£ miles southwest of Rosebud, was opened in the summer of 1918. The pit is leased by Dr. Cox, of Cuba. The product 

is hauled to Owensville.

The pit showed practically nothing but diaspore clay in the working face, the maximum length of which was 40 feet and the maximum 

height about 10 feet. A section of the pit is shown in figure 22. 

The diaspore clay was not of uniform quality from top to bottom; 

indeed it appeared to occur in beds. The upper bed was brownish, 

oolitic, and sandy, as well as more or less porous, and below this 

bed was a somewhat harder and denser diaspore clay in which the 

larger oolites were more scattered.

A sample of the lower bed was studied in this section. Under the 

microscope it shows a very fine-grained matrix that contains abundant kaolinite as well as 

diaspore. Coarser grains of 

diaspore make up the oolites. 

Rutile is very scarce.

_____________ There were no outcrops 

L- - - ^ ; ~"3A around the pit, and the size 

/ " - ~\ Of the deposit is not known.

It may or may not grade

FIGURE 22. Section in Charles Brown flint- into the Ordinary type of

clay pit, 2* miles southwest of Rosebud, flint

Mo. a, Overburden ; 6, flint clay ; c, rough- ^ _ .

textured porous diaspore clay ; d, oolitic BdU&TS (K 14 dtKinS pit. 

flint clay ; e, hard diaspore clay ; f, smooth The firm of Bauers & Watflint clay, largely concealed. . ., kins operates a pit 1 mile

east of Rosebud which has been in operation for two years. The 

main opening is about 125 feet long and about 75 feet in maximum width, but only the south side showed a good working face, as 

no excavating was being done at the other sides. At the west end the 

pit has run into sandrock, but it is claimed that the deposit extends 

beyond the limits of the excavation on the north and south. The 

material is all flint clay, of fine-grained texture and massive structure. There is no evidence of bedding, but the entire mass exposed 

in the working face (PL VIII, A) , which is about 20 feet high, shows 

irregular jointing.

A small opening had been made in August, 1918, about 600 feet 

west of the first pit, but it was not over 8 feet deep. Only the normal 

flint clay had J)een uncovered.

Heidel & Toelke pit. The firm of Heidel & Toelke has two pits 

near Rosebud. The pit that was being worked is 1 mile west of town. 

The opening is irregularly crescent-shaped (fig. 23) but has maximum diameters of about 250 and 200 feet.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE VIII

A. BARTERS & WATKINS FLINT-CLAY PIT, ROSEBUD, MO.

B. FLINT CLAY IN TOELKE & HEIDKL i'i I, Ku.Sb-BUD, MO.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE IX

INDIANAITE ATTACHED TO PEBBLY POTTSVILLE SANDSTONE. 

The indianaite occurs also as cement between the pebbles.
RESIDUAL CLAYS OF UNDETERMINED DERIVATION. 145

Most of the material is the usual hard flint clay (see PL VIII, #), 

but much red mottled clay and also some.coal is associated with it.

The coal, which is somewhat impure, occurs on the south side of 

the pit, where it forms a horizontal and in places a well-defined bed 

at least 1 foot in thickness. In some places it seems to be sharply 

separated from the flint clay, but at others it grades into the flint 

clay. Indeed, along the boundary the material is a mixture of graybrown massive clay and a conglomerate-like mass composed of 

rounded pellets and grains of flint clay embedded in a blackish 

matrix. These pellets and grains are elongated parallel to the bedding 

of the clay. Lumps and grains of pyrite occur both in the coal and 

in the clay near the coal. A little gypsum.was also noticed, in the 

form of small scales of selenite.

The conglomeratic material was fine grained throughout, but in 

general the same minerals were recognizable in the pellets as in the 

matrix. Among these minerals diaspore was abundant but very fine, 

kaolinite was fairly common, and 

there were the usual tiny grains of 

rutile.

The matrix surrounding the pellets had a chocolate-colored stain, 

but the pellets were practically free 

from it. No oolites were noticed.

In the west end of the pit the wall 

is sandrock, the northwest side of the 

pit is in reddish clay, and at the east 

end there is a flint clay that is 

streaked with red. The east face 

presents a most striking appearance, 

the thin red bands in general dip 

toward the north, but in places show 

curious contortions.

The flint clay is said to extend 20 feet below the present floor of 

the pit.

BLAND, GASCONADE COUNTY.

Shockley pit. H. H. Shockley has a small pit about 1£ miles west 

of Bland, on the north side of the Chicago, Rock Island & Pacific 

Railway, but is mining only plastic clay at present.

Camplell & LicJite pit. The firm of Campbell & Lichte has 

opened a pit one-eighth of a mile southeast of Bland on the property of D. Werfelman and has been operating for about a year. The 

total diameter of the deposit is said to be about 300 feet, and the 

pit, which has a much smaller diameter, is 40 to 50 feet deep. Clay 

outcrops on the north and west sides, but in the south and east walls 

sandrock is encountered.

led clay

0__________100 Feet

FIGURE 23. Plan of Heidel & 

Toelke pit, Rosebud, Mo.
146 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Hard clay had been found only in the lower part of the pit on the 

east side. All the rest of the clay was plastic. Most of it had the 

structure and texture of the normal flint but was appreciably softer. 

In places the clay is distinctly carbonaceous and contains plant fragments, none of them large enough, however, to be identifiable.

This clay is very fine grained and contains abundant kaolinite and 

hydromica but no observable diaspore. A few grains of rutile were 

also identified.

This firm has two flint-clay pits 2£ miles west of Bland and threefourths of a mile south of the railroad.

CANAAN, GASCONADE COUNTY.

A number of pits have been opened around Canaan, but only two 

were visited.

The pit of S. Haynes is 2 miles south of Ellis Spur. The diaspore 

clay forms a large lens, mostly on top of the flint clay, although some 

of the flint clay lies over it. There is no sharp line of separation 

between the diaspore clayxand the flint clay, the two grading into 

each other in a distance of about a foot. Only the best diaspore 

clay is shipped.

The following tests of the diaspore clay were made at the Bureau 

or Mines laboratory, Columbus, Ohio:

General physical tests of diaspore clay from Haynes pit, Ellis Spur, near

Canaan, Mo.

Workability- ________ Short; lacks plasticity; molds with

difficulty; cracks slightly in drying; grit visible.

Water of plasticity___________..__ ___per cent_ 23. 69

Air shrinkage, by volume_ ______________do____ 12.90

Air shrinkage, linear, calculated_________do_ 4.5

Modulus of rupture of raw clay__pounds per square inch__ 77. 2 

Fire tests of diaspore clay from Haynes pit, Ellis Spur, near Canaan, Mo.

Temperature (°Q.).

1,190.'..........................

1,250...........................

1,310...........................

1,370...........................

1,410...........................

Porosity 

(percent).

31.40

31.40

34.96

34.50

32.80

Color.

Buff..'............................

.....do............................

...:.do.. ..........................

.....do............................

Volume 

shrinkage, 

(per cent 

in terms of 

volume of 

dry clay).

10.60

10.61

11.69

12.80

13.50

Linear 

shrinkage 

(per cent 

in terms of 

dry clay).

3.8

3.8

4.0

4.6

4.7

Fusion point, cone. 35+. Steel hard at 1,190° C.

This is a very refractory clay of low bonding power. It can, however, be used for high-grade refractories if it is mixed with a more 

plastic clay.
INDIANAITE OF INDIANA. . 147

The Hensley pit, just west of Canaan, which is operated by Cox & 

Sassman, is worked only for smooth flint clay.

The Baxter pit, 1 mile south of Canaan, produces smooth flint 

clay.

The Helm pit, If miles north of Canaan, which was opened in the 

summer of 1918, is said to contain some diaspore clay.

The Lacey pit, three-fourths of a mile northeast of Canaan, produces only smooth flint clay.

The Dittmar pit, three-fourths of a mile southeast of Ellis Spur, 

or 2| miles southwest of Canaan, is worked by Cox & Sassman. It 

supplies both smooth flint clay and diaspore clay, but the diaspore 

clay is the one that is chiefly shipped.

The two Myers pits are 3 miles south of Canaan. They supply 

only smooth flint clay and contain no diaspore clay.

BELLE, MARIES COUNTY.

Three pits were being operated near Belle in 1918, as follows:

The Travis pit, 2£ miles south of Belle, supplies both flint clay and 

diaspore clay.

The Pointer pit, 2 miles south of Belle, ships only flint clay.

The Jackson pit, 1| miles southeast of Belle, produces only flint 

clay.

These pits are being worked by Heck Bros., who sell, in part at 

least, to Cox & Sassman.

INDIANAITE OF INDIANA.

Geologists and others have for many years known of the occurrence of a white clay in south-central Indiana, to which the name 

of indianaite was given by Cox in 1874.58 Dana 59 subsequently 

included this clay under halloysite, and Blatchley 60 still later refers 

to it as "kaolin or indianaite," but says that some of it consists of 

the mineral allophane.

Although this clay is widely distributed, its commercial .use has 

never been long successful, and consequently it has never been extensively developed.

GENERAL FEATURES OF THE DEPOSITS.

By W. N. LOQAN.

GEOGRAPHIC DISTRIBUTION.

Indianaite occurs along the contact of the Mississippian and Pennsylvanian rocks in Indiana, which extends from Benton County north

68 Cox, B. T., Porcelain, tile, and potter's clays: Indiana Geol. Survey Eighth, Ninth, 

and Tenth Ann. Repts., p. 154, 1879.

OB System of Mineralogy, 6th ed., p. 688, 1892.

88 Blatchley, W. S., The clays and clay industries of Indiana: Indiana Dept. Geology 

and Nat. Res., Twenty-ninth Ann. Kept., p. 54, 1905.
148 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

of Wabash River, on the northwest, to Perry County, on Ohio River 

at the south. The zone of this contact passes through the counties of 

Benton, Warren, Fountain, Montgomery, Parke, Putnam, Clay, 

Owen, Monroe, Greene, Lawrence, Martin, Orange, Dubois, Crawford, and Perry. (See fig. 24.) The contact is concealed by glacial

10 20 30 AC Miles

FIGURE 24. Map of part of Indiana showing area (shaded) that may contain 

indianaite. + , Known outcrop.

overburden in the northern part of the area, but from Monroe 

County southward the contact lies in the nonglaciated portion of 

the State, and hence in this region outcrops are more abundant. The 

width of the area where the contact is accessible differs from place 

to place but is about 12 miles in the northern part and about 18 

miles in the southern part. The attenuated margin of the Pennsylvanian rocks has been eroded in this region to such an extent that, as
INDIANAITE OF INDIANA. 149

a rule, they remain only on the tops of the high ridges which form 

the divides between the present drainage lines. In places these 

ridges rise 300 feet or more above the adjacent valleys, and the line 

of contact between the Mississippian and Pennsylvanian rocks is in 

many places 200 feet or more above the valleys. The ridges are decidedly irregular, and their margins are serrated by the indentations 

of minor drainage lines and their intervening spurs. The ridges in 

most places are capped by a soft sandstone which crumbles easily 

and therefore works down over and conceals the outcrops of the indianaite along the contact zone. Indeed, the mantle of sand thus 

produced is so general along the contact that good outcrops are exceptional. In some places a stream may cut in against the line of 

contact and expose the indianaite. In other places a spring may discharge its waters from beneath the bed of indianaite, and the quantity of water may be sufficient to carry away the detritus and form a 

perpendicular face at the outcrop.

Indianaite has not been reported from all the counties along the 

contact zone. It occurs in Owen, Greene, Monroe, Lawrence, Martin, 

and Orange counties, and has been reported from Dubois and C,raw- 

 ford counties. Serious attempts at development have been made 

only in Lawrence County, but even there actual production has been 

confined almost entirely to a small part of a half section. Outcrops 

of white clay occur in many places and test drifts, pits, and drill holes 

have revealed its presence in many sections in the southwestern part 

of the county. Explorations have been more extensive in this 

county than elsewhere in the indianaite belt, and for this reason the 

prospects there appear to be the best. Martin County probably offers 

the next best field for exploration and development, and Orange, 

Greene, Monroe, and Owen counties would follow, perhaps, in the 

order named.

GEOLOGIC OCCURRENCE.

The indianaite occurs near the contact between the Mississippian 

and Pennsylvanian rocks in Indiana. It seems to rest upon the 

Mississippian beds at practically all horizons, at some places as low 

as the top of the Mitchell limestone, at others on the lower Chester, 

at still others on the middle Chester, or even near the top of the 

Chester. It underlies the Pottsville (" Mansfield sandstone " of early 

reports) and lies at different horizons of the Chester, so that it must 

belong to the Pennsylvanian series. Further proof of its age is found 

in the occurrence, at one point at least, of a small body of indianaite 

above the main bed and in Pottsville sandstone, which rests upon 

the main bed of indianaite at this point. Another proof is found in 

the presence at one point of a stratum of clay that contains small 

quartz pebbles, similar to those which occur at this point and elsewhere in the base of the Pottsville and which have not been found
150 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

in the Chester. This stratum of clay rests immediately below the 

indianaite and in one place projects into the indianaite. (See fig. 25.)

CHARACTER OF THE OUTCROP.

The presence of pure white indianaite at the outcrop is rare, but 

not uncommonly small particles of white indianaite are distributed 

through the detritus that covers the outcrop. The weathered part 

of the bed at and near the outcrop consists of a mahogany-colored| 

clay, which contains small fragments of the white indianaite, espe~. 

cially in its upper part, which lies under sandstone ledges that ar& 

fairly compact. The mahogany color of the clay has doubtless 

originated in part from the staining of white indianaite by oxide

FIGURE 25. Neck of clay projecting into indianaite in the 

Gardner mine, near Huron, Ind. a, White indianaite; 6, sandstone ; c, black laminated clay.

of iron. The following analysis shows the composition of a sample 

of this material :

Analysis of mahogany-colored clay from Indiana. \

Silica (SiO>)______________________________ 33.04 

Alumina (Al2 0s)__________________________ 17.33 

Ferric oxide (Fe2O8 )________________________ 27.96 

Manganese oxide (MnO)__________________ 2.22 

Lime (CaO)____________________________ 1.52 

Magnesia (MgO) ___________________ 1.11 

Titanium oxide (Ti02 )___________-________ .69 

Alkalies (Na20,K20) _____________________ 1.77 

Volatile matter__________________________ 13.87

GENERAL CHARACTER OF THE CLAY.

In the mass the indianaite occurs either as coarsely granular material or as concretionary or other masses of porcelain-like appearance. These porcelain-like masses break into irregular fragments, 

which exhibit on some surfaces a conchoidal fracture. In some 

places the porcelain-like material has a wavy laminated structure
INDIANAITE OF INDIANA. 151

and is marked by stained lines and surfaces that are covered with 

projecting botryoidal masses of the white material that separates 

the layers of porcelain-like indianaite. In other places it is pitted 

with these small white granules of clay, which produce an amygdaloidal structure. These small granules have about the same degree 

of hardness as the surrounding indianaite. Under the microscope 

the porcelain-like indianaite exhibits a granular appearance. The 

grains are apparently spherical in form and in some sections are 

arranged in a dendritic structure. The dendritic structure may be 

due to the loss of water and consequent shrinkage when the section 

is heated during its preparation. In some places the white indianaite 

presents an irregular laminated appearance. This lamination seems 

to, be more clearly marked in the yellow clay than in the white. 

In some sections, however, the laminated appearance is due to the

presence of thin layers of yellow clay within the white. Concretionary masses occur in places in the white indianaite. These masses 

range in size from a few inches to 9 or 10 inches in diameter. The 

concentric layers are separated by thin lines of black and yellow 

stain. The white indianaite as a rule is hard, but in some places it 

is soft and very plastic, resembling in appearance a white ball clay. 

In other places the plastic clay is yellow and is interstratified with 

yellow or brown sand.

Both the granular and the massive varieties of indianaite may J?e 

translucent and greenish or they may show an opaque white body 

which resembles the fracture surface of bisque. The translucent 

form is in places composed of a series of small geode-like masses, arranged in a generally horizontal position. The walls are about oneeighth of an inch in thickness and the diameter of the cavities is from 

one-tenth to one-eighth of an inch. The interiors of the cavities are 

lined with a layer of milk-colored indianaite, which has a mammillary 

surface, and some of the cavities are wholly or partly filled with 

rounded grains of the same material. In one hand specimen five of 

these cavities are arranged in a horizontal distance of 2 inches. 

Cavities of different sizes are common in the indianaite. The porcelain-like form fractures irregularly and also has a conchoidal 

fracture.

The composition of a sample of the mine-run white clay is as 

follows:

Analysis of mine-run sample of white indianaite from Gardner mine.

Silica (Si02 )___________________________ 40.48

Alumina (A12 08 ) _________________________ 39. 60

. Hygroscopic water (H2 0 below 100° C.)___________ 5.01

Combined water (H2O above 100° C.)____________ 15.03

Ferric oxide (FesO8 )______________________ .11

100.23
152 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Layers of coarse or disconnected masses of coarse sand or sandstone, stained with iron oxide and containing small particles of white 

indianaite, occur in many portions of the bed of indianaite. (See 

fig. 28.) Separate blocks of sandstone are in places almost, if not 

completely, surrounded with white indianaite (fig. 26), and locally 

masses of sandstone are penetrated by a veinlike body of indianaite. 

(See fig. 27.) In one place a dark laminated necklike body of clay 

extends from a floor of similar material up into the indianaite. This 

clay contains pellet-like bodies of white clay, which are soft and 

plastic in place but hard and granular when dry. It contains also 

white oluartz pebbles, such as are found in the basal sandstone members of the Pottsville.

roof The clay has a fetid

odor similar to that 

of muck and contains 

concretionary masses 

of marcasite. At another point in the bed 

of indianaite next to 

the sandstone roof 

there were white and 

dark layers of indianaite above, then a 

layer of white, partly 

laminated indianaite

?;?? » ' FEET 1 below, and then a 4-

FIGURB 26. Section along north side of second cross en try -fnof ] a vpr of <?anrl

on east side of tunnel in the Gardner mine, near Huron, id^tu ui bdiuiInd. a, Sandstone; 6, milk-white clay; c, waxy clay; Stone, which OCCUpieS

d, clay that shows banded structure.

made by H. Ries.)

(Prom a sketch fUft lower Dart of the

. , mi i deposit. The sandstone layer was divided near its central part by a vein of white indianaite which extends through the 4-foot layer of sandstone. The 

layer of sandstone has a thin fin that extended upward obliquely into 

the white indianaite. This fin was about 5 feet in length and 1 foot 

thick in its thickest part. Above the lens of sandstone there are 

several concretion-like masses of indianaite, the porcelain-like layers 

of which are separated by dark stains. . (See fig. 27.)

ASSOCIATED ROCKS. °

The rock which everywhere overlies the indianaite, so far. as 

observations go, is sandstone of Pennsylvanian or Mississippian 

age. The character of the layer in immediate contact with the upper
INDIANAITE OF INDIANA. 153

surface of the indianaite is variable. The roof in places is composed 

of soft pink sandstone, in others of conglomeratic sandstone, and in 

still others of a rock that is firmly cemented and almost an iron ore 

in composition. The underlying rock in most places is a shale or 

clay.

In one locality a small body of white indianaite is completely surrounded with sandstone, in another thin layers of sandstone underlie 

the indianaite, and in a few others lenslike masses of limonite occur 

at the base of,the indianaite. These masses of limonite-contain 

quartz pebbles characteristic of the Pottsville formation.

Within the mahogany clay irregular eroded masses of limestone 

are sometimes found, and microscopic sections of this limestone show 

it to be highly fossiliferous. Within the indianaite bed the chief 

associated materials are sandstone, sand, conglomerate, and concreFIGUKB 27. White indianaite (clay) overlying sandstone, vein 

of indianaite crossing the sandstone, and fin of sandstone extending upward into the indianaite in the Gardner mine, near 

Huron, Ind.

tionary masses of limonite. A sample of the limonite from the base 

of the indianaite lias the following composition:

Analysis of limonite at base of indianaite from Lawrence County, Ind.

Iron oxide_____________________________ 83.73

Insoluble matter_________________________ 2.56

Loss on ignition___________*.______________ 12.02

Total iron.

100.31

58.61

A geologic section that was measured near Huron shows the relation of the indianaite to the underlying and overlying rocks. The 

section is as follows:
154 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Geologic section near Huron, Ind.

Feet.

Red, brown, and pinkish sandstone, conglomeratic at the base. 100 

Indianaite, 6 to 11 feet, average about_ ___ 6 

Black laminated clay, some gravel__________ _____ 3 

Unconformity. 

Shale, light green (Mississippian)__________ ______ 10

Limestone, bedding irregular______--________ ______ 20

Shale, plastic_____________________________ 38 

Limestone, reddish, thin-bedded_______:_____ ___ 7 

Shale, similar to above__________ ___ _ ,21 

Limestone, thick layers____________ ____ ___ 15

These limestones and shales below the unconformity belong~to the 

Chester group of the upper Mississippian.

EESOUKCES OF INDIANATTE.

A question of absorbing interest is, What is the available quantity 

of the white clay ? In the present state of development this question 

is difficult to answer. If the judgment is based upon the number of 

outcrops, the -conclusion is inevitable that the quantity is large. If 

the judgment is based upon the results of the meager development 

or upon the visible quantity of mahogany clay, the conclusion is 

similar. After going over the greater part of the field the writer 

believes that there is a large quantity of clay of all grades. In fact, 

it underlies thousands of acres of land in the counties mentioned, 

although how much of it is pure white can riot be estimated from the 

data which are at hand, but the total amount is probably large.61

THE DEPOSIT OF INDIANAITE NEAR HURON, LAWRENCE COUNTY,

IND.

By H. RIES. 

STRUCTURE OF THE BEDS.

The writer has not had the opportunity of making so extended a 

study of these deposits as Prof. Logan, with whom he spent two days 

in the field. During that time he visited several outcrops, as well as 

one accessible mine in Lawrence County, 4 miles northeast of Huron 

and 3 miles south of Williams. The opening is on the north side of 

the ridge on the Gardner property, where a tunnel has been driven 

southward into the hill for a distance of 300 feet. As the tunnel 

slopes gently downward from the entrance, it was not possible to 

examine it for a distance of more than 150 feet on account of accumulated water.

61 Blatchley, W. S., Clays and clay Industries of Indiana: Twenty-ninth Ann. Rept. 

Indiana Dept. Geology and Nat. Res., pp. 13-657, 1905.
INDIANAITE OF INDIANA. 155

The clay, as far as it was followed, occurs as a nearly horizontal 

deposit whose thickness ranges from 5 to 11 feet. The roof is formed 

by Pottsville ("Mansfield") sandstone of coarse pebbly character. 

The pebbles are of quartz, and the rock is open textured. In most 

places there seems to be a sharp line of demarcation between it and 

the clay, but in some places the contact is gradational. The conFIGURE 28. Angular pieces of pebbly sandstone completely surrounded by 

white clay in wall of crosscut about 50 feet from entrance of tunnel in 

the Gardner mine, near Huron, Ind.

tact of the clay with the roof is usually nearly horizontal, but at one 

place the roof dips so steeply toward the floor that in this entry the 

tunnel has been stopped. At this point also sandstone underlies the 

clay, and at one place the section shows a depression in the underlying sandstone about 12 inches wide and 12 inches deep, in which 

the boundaries are not perfectly sharp.

Clay

FIGURE 29. Indianaite overlying sandstone and vein of indiitnaite extending into the sandstone in the Gardner mine, near 

Huron, Ind. The specimen shown in PL IX was taken from 

the right wall of the vein sketched in the figure.

The floor in most of the mine was not clearly visible but was said 

to be mainly of Chester shale, although in places sandstone extended 

to the floor level.

Three curious and perhaps significant structural features are the 

occurrence of loose blocks of the sandstone in the clay (fig. 28); the 

occurrence of veinlike masses of the clay which cut across the bedding planes of the sandstone (fig. 29), one of them fully 8 or 10

77412 22 12
156 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

inches wide and 4 feet long; and the dissemination of clay in the 

loose blocks of sandstone which are embedded in the clay bed. . The 

clay occurs in the blocks of sandstone either as stringers that enter 

the blocks from the outside, or else apparently it forms the matrix 

around the pebbles.

PHYSICAL CHARACTER OF THE CLAY.

The waxy or earthy character of the white clay, the presence of 

druses, and the banded structure have already been mentioned by 

Prof. Logan. In several places the writer observed that the banding seems to follow the boundaries of the inclosed blocks of sandstone.

The clay is very fine grained. The waxy variety is massive and 

lustrous, and some of it is translucent on the edges.

On exposure to the atmosphere it dries out, loses its luster, and 

assumes a milky appearance. This change is accompanied by the 

development of cracks, owing to the loss of moisture, and bleaching. 

Thus, a sample that when fresh had a blue color closely resembling 

turquoise lost it almost completely in less than a month indoors.

The earthy variety is fine grained, soft, and generally white, but 

some of it is stained by iron or manganese. As far as the writer was 

able to enter the workings the clay was mainly white, but in the inner 

half of the tunnel it is mostly colored.

PETROGRAPHIC CHARACTER.

Two samples of the clay were examined petrographically. The 

massive waxy material contained a number of large flakes which are 

nearly or quite isotropic, except for minute inclusions. In addition, 

there were numerous spherulite-like grains (PL XXVIII, B, p. 297) 

which showed the interference colors of kaolinite. Rutile was fairly 

abundant in exceedingly minute grains.

The earthy variety of the clay showed numerous radiating bunches 

and even spherulites of a hydromica, possibly sericite. Kaolinite 

was also abundant, but in addition there were a number of comparatively large, clear, transparent flakes that had a slight bluish tinge 

and a moderate refractive index. Kutile was scarce.

One rounded lump of Pottsville sandstone was surrounded by a 

white claylike material that had a hyaline appearance when examined with a hand lens. This material when crushed and examined 

under the microscope showed a mass of .granular colorless isotropic 

fragments that had an index of refraction between 1.501 and 1.53. 

When tested with hot hydrochloric acid it gelatinized.

The hyaline character and the result of the gelatinization test 

agree with the properties of both allophane and schroetterite,
INDIANAITE OF INDIANA. 157

although only allophane has been reported in the indianaite. There 

is a difference, however, in their chemical composition.

The waxlike material, which has a slight luster when fresh, contained a considerable quantity of an isotropic mineral, which might 

be either halloysite or allophane. This material did not gelatinize 

with hydrochloric acid so abundantly as did the hyaline material. 

This, however, was to be expected, for it did not contain so much of 

the isotropic mineral. The drusy material is made up entirely of 

isotropic colorless grains.

As the two types of material are made up largely or wholly of 

isotropic grains, it is evident that some mineral other than kaolinite 

is present, and, as already stated, the clay has been described by 

different writers as containing halloysite and allophane.

It seemed probable, therefore, that the deposit might contain more 

than one hydrous aluminum silicate, and so partial analyses were

made of the two principal types the waxy clay and the hyaline 

material which occurs close to the pebbly sandstone in places and 

also forms drusy masses. The composition of these two types of 

material, together with the theoretic composition of allophane, 

schroetterite, and halloysite, are given in the following table.

Analyses of clays from Gardner mine, near Huron, Lawrence County, Ind., and 

composition of allophane, schroetterite, and halloysite.

Silica (SiO»). ............................ '............

Alumina (A1303 ) ....................................

Water above 100° C. (HS0+) . .......................

Ferric oxide (Fej08 ) .................................

Water below 100° C. (H5 0- ) ........................

1

43.47

38.03

14.73

} .,5

3.82

2

10.70

54.53

29.48

.37

5.26

3

23.80

40.5

35.7

4

11.70

53.1

35.2

5

 43. 5

36.9

19.6

1. Waxy clay, Gardner mine. George Steiger, analyst.

2. Hyaline material, same place. George Steiger, analyst.

3. Allophane. Dana, System of mineralogy, 6th ed., p. 693,1912.

4. Schroetterite. Idem, p. 694.

5. Halloysite. Idem, p. 688.

A comparison of the analyses given in the table shows that the hyaline material resembles schroetterite, but the waxy clay agrees more 

closely with halloysite than allophane. It is not pure halloysite, however, for the microscopic examination shows that the material contains some kaolinite and hydrous mica.

Both samples from the Gardner mine probably contained more 

moisture when collected than they did when analyzed, for they lost 

some of it by air drying.

The local occurrence of schroetterite in the Gardner mine in botryoidal masses indicates that it was evidently deposited from solution, and several of the occurrences mentioned by Dana 62 appear to 

have a similar origin.

82 System of mineralogy, 6th ed.. p. 694, 1912.
158 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES, 

x 

BELATIONS OF THE CLAY TO THE BOCKS ASSOCIATED WITH IT.

Further interesting facts .are observed on examining the relation 

of the clay to the pebbly sandstone.

A specimen of pebbly Pottsville sandstone with white clay attached 

is shown in Plate IX. The clay is the marginal portion of a welldefined vein that cuts directly across the bedding of the sandstone. 

(See fig. 29.) Although the contact between the clay and the wall 

rock appears to be sharp, nevertheless close examination shows that 

the clay penetrates the pores of the rock, and even cracks in the 

pebbles. One pebble 0.2 by 0.3 inch is cut across by a veinlet of white 

clay 0.01 inch wide. The sides of the clay-filled crack are irregular 

and the projections on one wall of the crack are not opposite any 

corresponding depression on the opposite side.

The pebbles of the sandstone commonly show decided evidence of 

corrosion, and in places there are clayey patches larger than the usual 

interstitial spaces between the pebbles. Both clay and limonite may 

be present in the pore spaces of the rock.

There is no doubt that this clay is markedly different in mode of 

occurrence from any other deposit yet described.

It is clearly rather closely associated with the unconformity between 

the Pottsville and the Chester, but apparently lies in places in the 

Pottsville or (according to Logan) in places even within the Mississippian. This contact, which is an erosive unconformity, is very 

irregular and does not lie at a uniform elevation, even though the 

beds locally may appear to be practically flat. The horizon of the 

white clay may change in altitude 100 feet in a comparatively short 

distance, and between Bloomington and Huron, according to Logan, 

the difference in the elevation of the clay is 250 feet.

Although the clay has been found at many points it is not definitely 

known to be a continuous deposit.

Whatever theory of origin is advanced, it seems to the writer that 

the following facts must be borne in mind:

1. The deposit is essentially bedlike in its character.

2. It may surround lenses of Pottsville sandstone.

3. It may contain angular or rounded blocks of Pottsville sandstone.

4. Bodies of the clay may occur in Pottsville sandstone.

5. The clay is in places sharply separated from the sandstone, but 

in other places it grades into the sandstone.

6. Stringers or veinlike masses of the clay penetrate the Pottsville 

in places directly across the bedding.

7. The clay locally shows a banded structure parallel with the 

horizontal surface either of the sandstone or of the inclosed blocks 

of the sandstone.
INDIANAITE OF INDIANA. 159

8. The waxy clay forms irregular patches in the earthy material.

9. Cavities lined with drusy masses of a whitish material occur 

in the clay.

10. At one point a pipelike mass of shale containing pellets of the 

white clay extends upward into the main clay deposit.

THEORIES OF ORIGIN. 

COMBUSTION OF COAL BED.

In 1859 Leo Lesquereux,63 in writing of the white clay, expressed 

the opinion that it represented the residue left by the burning of a 

bed of coal. This view can not be correct, for the reason that the 

heat of the burning coal would have dehydrated the clay and baked 

it, which has not occurred. Some interesting data on this point have 

recently been given by Rogers.64

ALTERATION OF LIMESTONE. /

E. T. Cox ° 5 conceived the idea that the clay had been formed by 

the decomposition of a bed of limestone, which at other points lies 

at the same horizon instead of the clay. Logan 80 states that the 

limestone mentioned by Cox has been brought to the approximate 

elevation of the deposit of indianaite by a fault that trends about 

N. 60° E. in that region.

It is interesting to quote a portion of Cox's description, even 

though his theory was probably incorrect. He says:

The clay (kaolin) lies immediately beneath the Millstone grit or pebbly conglomerate of the coal measures and here occupies the place of a bed of Archimedes limestone, which is seen in situ about 2 miles southeast of the mine. 

Though similar in its composition to kaolin, this clay differs physically and 

owes its origin to an entirely distinct set of causes and effects. While the 

former is derived from the decomposition of the feldspar of feldspathic rocks, 

such as granite, porphyry, etc., the porcelain clay of Lawrence County has 

resulted from the decomposition, by chemical waters, of a bed of limestone 

and the mutual interchange of molecules in the solution, brought about by 

chemical precipitation and affinity.

Although this explanation is a little vague, it seems to indicate the 

idea of replacement.

Maurice Thompson °7 thought Cox's theory was correct but added 

the explanation that rain water filtering through the overlying

M iLesquereux, Leo, Report on the distribution of the geological strata In the coal 

measures of Indiana: Report of a geological reconnaissance of Indiana made in 1859-60 

by R. Owen, p. 320, 1862.)

64 Rogers, G. S., Baked shale and slag formed by the burning of coal beds: U. S. Geol. 

Survey Prof. Paper 108, pp. 1-10, 1917.

68 Cox, E. T., Indiana Geol. Survey Sixth Ann. Rept, p. 15, 1874.

88 Private communication.

<" Thompson, Maurice, The clays of Indiana: Indiana Dept. Geology and Nat. Hist. Fifteenth Ann. Rept., p. 37, 1886. 

I
160 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

pebbly sandstone gathered and carried down with it sufficient silica 

and alumina to replace the carbonate of lime dissolved.

A modification of this theory was later suggested by W. H. Thompson,68 who believed that the silica and alumina of the clay were a 

combination of the insoluble constituents of the limestone, together 

with additional quantities of the same substances leached out of the 

overlying sandstone by percolating meteoric waters. He also thought 

these waters brought down a trace of mica in a fine state of division.

DEPOSITS OF RESIDUAL CLAY.

According to another theory the clay was derived by the weathering of Chester shale or Pottsville sandstone. However, the sandstone in places lies between the clay and the shale, and even where 

the sandstone is not present, there seems to be no transition zone 

showing the passage of the clay into shale, so that it is not likely 

that the clay was derived from the shale. It could not have been 

derived from the sandstone where that rock overlies it, for the 

material of which the sandstone is composed is not likely to form 

residual clay.

IGNEOUS INTRUSION.

According to still another theory the clay represents a decomposed sheet of intrusive rock. There are serious objections to this 

theory, because the clay shows no evidence of remains of the original 

texture, and it seems unlikely that such a sheet should have followed 

the uneven contact so closely; nor would it account for the bodies of 

clay, some of them of indefinite boundary that occur in the sandstone 

above the main body of the clay. Moreover, such an intrusion would 

have affected the shale, and there is no evidence that this occurred. 

Furthermore, in such an apparently extensive deposit of clay some 

less altered igneous rock would probably remain, and besides the 

areal extent of the deposit seems too great for that of an igneous 

mass of such slight thickness.

VEIN DEPOSITS.

According to another theory the clay was deposited in veins, having 

been introduced in solution along the lines of contact between formations. The deposition of hydrous aluminum silicates by this 

method has not usually been recognized, and, moreover, it is difficult 

to conceive how a horizontal cavity from 5 to 11 feet high could have 

been formed and held open until it was filled.

88 Thompson, W. H., Outline sketch of the most valuable minerals of Indiana: Indiana 

Dept. Geology and Nat. Hist. Sixteenth Ann. Rept, p. 78, 1888.
INDIANAITE OF INDIANA. 161

Bastin and Laney,69 however, have noted the occurrence of kaolinite in cavities, where they state it has been deposited either from 

suspension or solution. The curious banding observed in places an4 

the geodal cavities tend to favor the theory of deposition in veins, 

but it is perfectly possible to find geodes in sedimentary clay deposits. 

Indeed, the writer has seen quartz-lined geodes 3 inches across in 

the clay of the Fort Payne chert in Alabama.

SEDIMENTARY DEPOSITS.

The theory that the clay is of sedimentary origin is likewise inapplicable. It may appeal to one on first thought, but if true how 

are the detached blocks of Pottsville sandstone found in the clay to 

be accounted for? They show no evidence of having been detached 

from the roof and sinking into the clay, nor does it seem possible that 

they are a type of intraformational conglomerate, because veinlets 

and impregnations of the clay extend from the exterior of the blocks 

toward their interior. Any correct theory must explain these details.

BIOCHEMICAL REACTIONS.

Logan T0 suggests that bacteria have played an important part in 

the production of aluminum sulphate, which has reacted with the 

quartz of the Pottsville sandstone and produced the white clay. The 

full details of the theory have been published elsewhere.70*

REPLACEMENT OF QUARTZ PEBBLES.

The theory favored by the writer is that the white clay was formed 

by the replacement of the quartz pebbles of Pottsville sandstone, at 

least where the clay occurs in that formation. So far as the end 

result is concerned this theory agrees in part with Logan's theory.

The details of the process are not perfectly clear and would require considerable field and laboratory study, but the conclusions are 

based mainly upon a somewhat careful study of the tunnel in the 

Gardner mine and of specimens collected there.

Certain facts, however, seem to warrant the conclusions drawn. 

The pyrite of the Chester shales would by contact with underground 

waters be decomposed and yield sulphuric acid, which would attack 

the alumina of the shales and form aluminum sulphate. As the unconformity between the Chester group and the Pottsville is' a line of 

weakness, and the sandstone of the Pottsville is very porous, a good

89 Bastin, B. S., and Laney, P. B., The genesis of the ores of Tonopah, Nev.: U. S. 

Geol. Survey Prof. Paper 104, p. 38, 1918.

70 Logan, W. N., A biochemical theory of the origin of Indianaite: Science, new ser., 

vol. 49, p. 197. 1919.

700 Logan, W. N., Kaolin of Indiana : Indiana Dept. Conservation. Pub. 6, pp. 35-76, 1919.
162 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

path is formed for the circulating waters to follow, and hence the 

sulphate solutions would be brought in contact with the quartz pebbles of the Pottsville. Aluminum sulphate will attack silica, although 

the exact reaction by which the hydrous aluminum silicate is formed 

can not be stated. The pebbles of the sandstone show distinct evidence of corrosion and replacement, as noted on page 158.

This theory would also account for the isolated blocks of sandstone in the clay, the irregular boundaries between clay and sandstone, the veins of clay in sandstone, the gradation of one into the 

other, and the isolated bodies of clay in the sandstone such as are 

seen above the main entrance to the Gardner tunnel.706

If this theory is correct the clay must be of post-Pennsylvanian 

age.

The formation of white clay by replacement has not ordinarily 

been recognized, and yet it does not seem to be impossible. Certain 

hard kaolins of the Tintic mining district, Utah, are said to have 

been formed by the replacement of crystalline limestone by descending waters,71 but there is no evidence that this process has operated 

to any appreciable extent in the igneous rocks of the district.

SEDIMENTARY CLAYS OF THE COASTAL, PLAIN AND 

THE EMBAYMENT AREA.

GEOLOGIC RELATIONS.

Along the Atlantic border of the United States from Cape Cod 

to Florida there is a plain which slopes gently seaward and which 

at its southern end swings westward through Alabama, Mississippi, 

and Louisiana to Texas. Near the coast the plain is near sea level 

and the sections exposed in the stream valleys are not very deep, 

but toward its inner edge the surface is several hundred feet higher 

and the streams have cut deeper into the formations, so that thicker 

sections are exposed.

Underlying the surface of this Atlantic and Gulf Coastal Plain 

(PI. X) occurs a series of Cretaceous and Tertiary deposits which 

dip gently seaward, and as the Cretaceous beds are the older geologically, where they are present they outcrop in general along the 

inner border of the plain.

Overlying these deposits unconformably still later formations in 

places conceal the older ones, except where cut through by stream 

erosion.

These uppermost formations might therefore, even though thin, 

effectively hide the underlying beds.

rob The writer has recently seen several small deposits of Indianaite in Hardin County, 

Ky., where it occurs immediately below the Pottsville conglomerate and probably represents a replacement of it.

n Ldndgren, Waldemar, and Loughlin, G. F., Geology and ore deposits of the Tintic 

mining district, Utah: U. S. Geol. Survey Prof. Paper 107, pp. 258-261, 1919.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE X

£$N£>lB 

Lirwa^ygJT; 

A^f^tA 

^^..tMCTCAlJli^Iiajfesto^

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^ V '^BJORE'l

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EXPLANATION

Wilcox group in Georgia, Alabama, and 

Mississippi; with perhaps some later Eocene 

in northwestern Mississippi ; Lagrange formation (comprising 

Wilcox, Jackson and 

possibly Claiborne 

deposits) in Tennessee 

and Kentucky

( Lenticular teds of sands and

clays, with shell marls in

Alabama)

Williamsburg and

Black Mingo

formations

(Sand and fuller's earth)

Eutaw formation

(Chiefly glauconitic sands

and subordinate laminated

clays)

03

13

o

al

UJ 

CE 

O

Tuscaloosa formation "/

(Sands and clays)

Middendorf arkose

member of Black Creek

formation (in South

Carolina only)

(Arkosic sands and clays)

Lower Cretaceous

(Sands and clays)

Paleozoic basement 

rocks

Crystalline rocks of the 

Piedmont Plateau

MAP OF SOTJTHEASTEKN STATES

- LITHO. A.HOEN SLCD. BALTO.MD.

Showing distribution of Tertiary and Cretaceous formations, which carry high-grade clays

75 100 Miles

Scale 2,500,000

25 50

1922
Geologic distribution of high-grade days in the Coastal Plain and the JSmbayment Area.<*

Eocene.

Cretaceous. Upper 

m

t» 

O 

S

West Kentucky.

Lagrange. 6 

Ball clay, sagger 

clay, refractory 

bond clay.

Porters Creek. 

Wad clay.

Ripley. 

No high-grade 

clays known.

Eutaw. 

No high-grade 

clays.

Tuscaloosa. 

Probably no clays.

West Tennessee.

Ball clay, refractory bond clay, 

sagger clay.

Porters Creek. 

No high-grade 

clays.

Ripley. 

Ball clay and 

sagger clay.

Selma chalk.

Eutaw. 

No high-grade 

clays.

Tuscaloosa. 

Probably no clays.

Northern 

Mississippi.

Wilcox. 

Refractory bond 

clay, stoneware 

clay.

Midway. 

No high-grade 

clays.

Ripley.

Selma chalk. 

No high-grade 

clays.

Eutaw. 

No high-grade 

clays.

Tuscaloosa. 

White clays.

Western 

Alabama.

Wilcox. 

No high-grade 

clays.

Midway. 

No high-grade 

clays.

Selma chalk. 

No high-grade 

clays.

Eutaw. 

No high-grade 

clays.

Tuscaloosa. 

Well-developed 

white clays.

Central Alabama .

Wilcox. 

No high-grade 

clays.

Midway. 

No high-grade 

clays.

Ripley.

Selma chalk. 

No high-grade 

clays.

Eutaw. 

No high-grade 

clays.

Tuscaloosa. 

White clays.

Not exposed and not known to be present.

Eastern Alabama.

Wilcox. 

No high-grade 

clays.

Midway. 

No high-grade 

clays.

Ripley. 

No clays.

Eutaw. 

No high-grade 

clays.

Western Georgia.

Wilcox. 

No high-grade 

clays.

Midway. 

No high-grade 

clays.

Ripley. 

Some white refractory clays.

Eutaw. 

No high-grade 

clays.

Central Georgia.

Absent.

Midway. 

No high-grade 

clays.

Ripley. 

Some white refractory clays not 

white burning.

Absent.

Eastern Georgia.

Absent.

Absent.

Absent.

Absent.

Absent.

Present.

Present. 

Plastic white 

clays.

!

Present. 

Plastic white 

clays.

Present. 

Plastic white 

clays.

South Carolina.

Williamsburg. 

No high-grade 

clays.

Black Mingo. 

No high-grade 

clays.

Peedee. 

No clays.

Black Creek. 

White plastic 

clays in Middendorf arkose 

member.

(?)

North Carolina.

Absent.

Absent.

Peedee. 

No clays.

'

Black Creek. 

No clays.

.........m.........

Present. 

Plastic -white 

clays.

Present. 

Correlated with 

Patuxent formation. No highgrade clays have 

yet been discovered.

; ; 

Virginia. Maryland.

i

Pamunkey. 

No high-grade 

clays.

Absent.

Not exposed in 

Virginia. 

Known in well 

borings only.

Patapsco. 

No high-grade 

clays.

Arundel. 

No high-grade 

clays.

Patuxent. 

No high-grade 

clays.

New Jersey.

i Pamunkey. ' 

: No high-grade i Absent. 

! clays. 1

i '

1 

Absent. Absent.

i

Absent.

Rancocas. 

No high-grade 

clays.

Monmouth. 

No high-grade 

clays.

Matawan. 

No high-grade 

clays.

Magothy. 

No high-grade 

clays.

Break.

Raritan. 

Small lenses of 

white sandy 

clay.

Patapsco. 

Possibly refractory 

bond clays.

Arundel. 

Some crucible 

clays.

Patuxent. 

No high-grade 

clays.

Manasquan. 

No high-grade 

clays.

Rancocas. 

No high-grade 

clays.

Monmouth. 

No high-grade 

clays.

Matawan. 

No high-grade 

clays.

Magothy. 

No high-grade 

clays.

Break.

Raritan. 

Valuable series of 

fire clays, sagger 

clays, some ball 

clays, etc.

Absent.

o The white clays of Florida lie geologically above formations shown in this table. In Arkansas and Illinois small deposits of clay are known in the Wilcox and Lagrange formations. 

v The Lagrange formation includes beds of Wilcox, Jackson, and possibly of Claiborae age.

77412 22. (Face p. 162.)
SEDIMENTARY CLAYS. 163

An extension of the Coastal Plain formations stretches northward 

in the Mississippi Valley from Mississippi and Texas, across eastern 

Arkansas, southeastern Missouri, and western Kentucky and Tennessee as far as southern Illinois. This extension is known as the 

Embayment Area, because the beds were deposited in a long, broad 

arm of the sea.

The Cretaceous and Tertiary deposits are of special interest to us 

in this discussion. They consist in general of a series of clays, sands, 

gravels, sandstones, limestones, and similar materials.

In the Atlantic Coastal Plain they dip gently toward the Atlantic 

Ocean, in the Gulf Coastal Plain toward the Gulf, and in the Embayment Area toward the Mississippi.

As a whole they show two marked features: 1. Any one formation is not continuous throughout the Coastal Plain and the Embayment Area, either because it was not deposited over the entire region 

or because it may have been worn away in places. 2. The individual 

formations in general show a marked lithologic change in tracing 

them from one State to another. Thus, a formation which contains 

valuable deposits of clay in one State may be made up almost exclusively of sands in another.

Some idea of this variation may be seen from the series of columnar sections given in the accompanying table, which includes the 

Upper and Lower Cretaceous and part of the Tertiary. This table 

also shows the States in which the different formations carry highgrade clays, and Plate X shows the area! distribution of these 

formations in most of the Coastal Plain and Embayment Area.

The table shows, for example, that the Lower Cretaceous deposits, 

so valuable as a source of the white clays of Georgia and South Carolina, do not outcrop west of eastern Alabama, nor are they definitely 

identified north of South Carolina, although the Lower Cretaceous 

Patuxent formation of North Carolina and Maryland may possibly 

be the northward continuation of them. Even so, it is of quite different lithologic character. On the other hand, the Ripley formation has been identified as a broken belt from Kentucky all the way 

to central Georgia, but it carries few clays of value.

The clays of the several formations are described separately, and 

their distribution, characters, and uses are indicated.

METHODS OF MINING.

With very few exceptions the clays of the Coastal Plain and the 

embaymerit area are worked as open pits. In southern Illinois, however, shaft mining is common.

The overburden, if thin, is removed with picks and shovels or 

scrapers, but where it is thick steam shovels are not infrequently em-
164 HIGH-GRADE CLAYS OF THE EASTEEN UNITED STATES.

ployed, and in the larger pits the stripping so removed is loaded 

into cars, which are hauled to the dump by steam power.

The white clays of Georgia and South Carolina are in places excavated with a steam shovel, but this method is inapplicable at most 

pits in western Tennessee and Kentucky for the reason that the 

same pit may contain several grades of clay of different thicknesses, 

so that the only way to excavate the material is by hand.

In Florida a unique method of dredging1 the clay is employed, and 

the conditions there favor it.

Throughout this region washing the clay for market is practiced 

only in certain States. Some of the New Jersey ball clay has been 

washed; most of the Georgia white clay, some of the South Carolina 

clay, and all of the Florida white clays are washed for market. At 

all other localities the clay is shipped as mined, except that in some 

places it is crushed.

Shippers of white clays from Georgia and South Carolina especially should see that the product is properly dried before sending 

it to the market, and all the clay that is shipped crude should be 

carefully sorted to avoid the inclusion of discolored or sandy streaks, 

which may injure the quality of the shipment.

LOWER CRETACEOUS CLAYS.

The Lower Cretaceous deposits are not extensive in the Coastal 

Plain region, though they occur from western South Carolina to 

central Alabama (PI. X). It is unfortunate that they are not more 

extensive, because they contain some of the purest clays found in the 

Coastal Plain area, which have been used in part to replace some of 

the white clays hitherto imported from England.

The materials that make up the Lower Cretaceous deposits in this 

area consist of irregularly bedded, coarse feldspathic and micaceous 

sands, together with lenses and bed's of clay, some of them of high 

purity. They rest unconformably on the older crystalline rocks and 

are in turn overlain unconformably by the Upper Cretaceous and 

Tertiary formations.

A short distance west of Alabama River the Lower Cretaceous 

passes under and is completely buried by the overlapping beds of 

the Tuscaloosa formation.

SOUTH CAROLINA.

BY W. S. BAYLEY. 

THE CLAY-BEARING FORMATIONS.

The white sedimentary clays of South Carolina occur in the Lower 

Cretaceous and also in the Middendorf arkose member of the Black 

Creek formation of the Upper Cretaceous, but mqst of the production 

comes from the Lower Cretaceous.
U. 8. GEOLOGICAL SURVEY BULLETIN 708 PLATE XI

1 McNamee

2 South Carolina

3 Paragon

4 Peerless

5 Immaculate

6 Parker

7 Edisto

8 Interstate

9 Keenan (not operating)

PROSPECTS. 

A Hill Bros. 

B. Mims 

C Mrs.Geiger 

D Henderson Bros. 

E Coker 

FBox

MAP OF SOUTH CAROLINA SHOWING DISTRIBUTION OF CRETACEOUS CLAY-BEARING FORMATIONS AND CLAY MINES.

77412 22. (Face p. 164.)
SEDIMENTARY CLAYS. 165

The accompanying map (PL XI) shows the extent of the white 

clay-bearing formations in South Carolina, as well as the operating 

pits and some other properties that are still undeveloped. The undeveloped properties that are represented include only those that were 

visited, and there are no doubt a number of others.

The Cretaceous area that contains the white clays forms a belt 

between the " fall line" and the Tertiary area to the east. This 

belt is narrow at Aiken, but it increases in width to the northeast 

and is 45 miles wide between the Congaree and Wateree rivers, 

though it is not continuous throughout this distance. Beyond this 

point it is about 30 miles wide. All the productive clay deposits 

are within this belt, though a few promising deposits that may be 

productive in the future lie in the crystalline area to the west.

The Lower Cretaceous beds in South Carolina are divided by Sloan 

into the "Lower Hamburg beds" and "Upper Hamburg beds." 

They are overlain unconformably in some places by the younger Cretaceous beds and in others by the Eocene formations, and these in 

turn are overlain by still later deposits. In some places the Tertiary 

beds are absent, and the post-Tertiary beds rest directly on the 

younger or Upper Cretaceous beds.

Near the fall line, as has been stated, the Cretaceous deposits lie 

at the surface, but toward the southeast they disappear under 

younger beds, and these in turn occupy the surface in succession.

The Cretaceous beds, where they are well exposed, as in the Aiken 

district, are about 275 feet thick, the various members being distributed as follows:

Geologic section in Aiken district, S. V.. 

Pliocene:

Unconformity. 

Eocene:

Unconformity. 

Upper Cretaceous:

Peedee formation 

Marls.

Black Creek formation 

Black shales and clays.

Middendorf arkose member Feet. 

Greenish-yellow and white hard clay 18 

Micaceous sands____________________ 12 

Greenish-yellow and-white hard clay_______ 15

Mixed sands ______________ ____ 9

White-clay nodules. 

Erosional unconformity.

Cross-bedded white and colored sands _ . ._ 30 

Erosional unconformity.

Thin layers of clay and sand___________ 7 

Round quartz pebbles and sand__________ 2 

Unconformity.
166 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Lower Cretaceous:

"Upper Hamburg beds" Feet. 

Fine white plastic clay__________________ 14 

White sands and white clay_______________ 9 

White arid yellow sands with white-clay lenses___ 28 

Nodules of white clay.

Erosional unconformity.

"Lower Hamburg beds" 

Mealy, micaceous sands________________1 

White and colored sands and white clay________ I 51 

Harsh sands________________________j 

Harsh white arkose____________________ 19 

Purple clay ____________________________ 11

Coarse white and yellow sands_____________ 25 

Fragments of quartz and gneiss in clay________ 4

Unconformity. 

Pre-Cretaceous shales, gneiss, granite, and other rocks.

The position of the " Hamburg beds " in the geologic column has 

not been definitely established. They are unquestionably near the 

base of the Cretaceous, and probably, according to Stephenson,72 

correspond to the Patuxent ("Cape Fear") formation of North 

Carolina.

In this paper both the " Lower Hamburg beds " and " Upper Hamburg beds " of Sloan 78 are classed together as Lower Cretaceous without any more specific designation.

The Middendorf beds are placed by Stephenson 7 * in the Upper 

Cretaceous and are regarded by him as a shallow-water phase of the 

lower part of the Black Creek formation. The typical beds of the 

Black Creek formation occur in the valley of Peedee River and its 

tributaries, and the Middendorf arkose member is seen in a comparatively narrow belt from Chesterfield southwest to Aiken County. 

The narrowing down of the surface exposures of the Middendorf to 

the south is due to an overlap of Eocene beds from the southeast.

THE OLAY BEDS.

Clay occurs in distinct beds over a large part of the area that is 

mapped as underlain by Cretaceous rocks (PI. X). It outcrops in 

numerous places, and there is no reason to believe that it is not continuous between outcrops under the sands that form the uplands between the stream valleys.

Though the clays seem to form somewhat continuous deposits, they 

occur at different horizons in the Lower Cretaceous deposits and in 

the Middendorf member. The lowermost horizon is in the Lower

*» Stephenson, L. W., Index to the stratigraphy of North America: U. S. Geol. Survey 

Prof. Paper 71, p. 605, 1912.

78 Sloan, Earle, A preliminary report on the clays of South Carolina: South Carolina 

Geol. Survey, ser 4, Bull. 1 (Reports on Resolutions, vol. 2), pp. 816, 823, 1904.

74 Stephenson, L. W., op. cit., p. 659.
SEDIMENTARY CLAYS. 167

Cretaceous about 30 feet above its base. In some places the clay 

reaches 11 feet in thickness, but in other places it is entirely absent. 

It is generally fine grained and smooth, but in some places it is 

gritty and indurated. In the main it is stained purple with organic 

matter,75 but locally it is white.

Streaks and lenses of white clay are also interbedded with sands 

in the lower portions of the Lower Cretaceous, but the principal bed 

and the one which is by far the most productive in the State is that 

at the top of this series. It is exploited at Bath and Langley, where 

it is exposed on the sides of,gullies at an average elevation of 307 

feet. It dips steeply eastward and southward and passes under the 

overlying Middendorf beds. To the north and west it rises to the 

surface and disappears as the result of erosion. Its maximum thickness is about 18 feet, and its average thickness where worked is about 

12 feet. In some of the valleys it has been cut through by streams 

and removed from the bottoms. In other places it was removed by 

erosion before the overlying beds were laid down, and in still other 

places perhaps it was never deposited. As a rule, the clay in this 

bed is white, fine grained, smooth, and very plastic. It is put on the 

market without other preparation than drying, except that some of it 

is crushed. In some places it is stained purple like the bed in the 

lower part of the Lower Cretaceous and in other places it is stained 

yellowish or brownish by iron hydroxides.

Unconformably above the Lower Cretaceous beds lie the Middendorf beds, in the lower, portion of which other streaks of white clay 

are interbedded with sands. At its top, however, occur two beds, 

15 feet and 18 feet thick, which in some places are separated by 12 

feet of sand but in other places coalesce and form a single bed 24 

feet thick. In the vicinity of Langley the upper surface of the clay 

is about 95 feet above that of the Lower Cretaceous white clay. This 

clay differs from the lower clay in some respects. It is dense, has a 

somewhat waxy luster, and most of it is pale drab, though locally it is 

white or very pale green. This bed is noted by Sloan 78 as " the most 

extensively distributed, approximately homogeneous member of the 

Cretaceous formations exposed in South Carolina. It is the only one 

of the Cretaceous white clay beds that even roughly approximates 

regional continuity." Its character changes abruptly from place to 

place. It is gritty at some places, fine grained at others, and dense 

and waxy at still others.

Analyses of characteristic samples of both the Lower Cretaceous 

and the Middendorf clays are given below. They are all quoted from 

Sloan's report.

78 Sloan, Earle, op. dt., p. 817. 

78 Idem, p. 821.
168 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

Analyses of Cretaceous clays from South Carolina.

Silica (SiOj).............. ......

Alumina (AljO3 ) ...............

Ferric oxide (FejOs) ............

Lime (CaO) ....................

Soda(NajO)....................

Potash (KsO). .................

Titanium oxide (TiOs) .........

Quartz .........................

Feldspar. ........... j ...........

1

45.02

38.98

.77

.03

.07

is

.26

.85

13.58

100. 11 

96.95

2.00

1.16

2

44.66

37.90

2.53

.08

.41

.36

1.29

13.17

100.40 

99.60

.16

.64

3

AA 93

38.92

2.31

.12

Trace

.26

30

1.21 19 on

100. 25 

99.29

.49

.47

\

45.07

35.61

2.21

.16

.25

1 37

1.10

1.56

1O OQ

99.72 

90.62

3.52

5.58

5

45.69

37.47

1.01

69

.08

1.44

13 OS

100.36 

94.68

3.76

1.92

6

47.49

35.56

2.47

.74

.13

.94

12.86

100.19 

96.43

2.27

1.49

7

Afi 00

36.08

1.02

1 09

.20

.86

13.82

100.06 

88.99

4.53

6.54

FIGURE 30. Section she-wing unconformity in 

t>it of McNamee Kaolin Co., near Bath, 

S. C. a, Red sand; b, white sand 

layers of clay; c, clay.

1. Lower Cretaceous clay, McNamee pit, near Bath.

2. Lower Cretaceous clay. Peerless Clay Co., near Langley.

3. Lower Cretaceous clay, Immaculate Kaolin Co., near Langley.

4. Lower Cretaceous clay, Langley Manufacturing Co., near Langley.

5. Middendorf clay, Imperial Kaolin Co., near Seivern.

6. Middendorf clay, Richard place, Wise Creek area.

7. Middendorf clay, Edisto Kaolin Co., Rayflin.

PITS IN LOWER CRETACEOUS CLAYS. 

BATH, AIKEN COUNTY.

Property of the McNamee Kaolin Co. The property of the McNamee Kaolin Co. comprises about 2,000 acres about 1£ miles northeast

of Bath. The main office is 

at Broadway and Fiftyfourth Street, New York. 

As the company has been operating for forty years, all 

the clay has been removed 

from an area of several acres, 

811(1 and a number of large pits

have been left.

In the pit now being worked red and white sand constitute the main 

portion of the overburden, which ranges in thickness from 3 to 33 

feet, depending upon the topography. Evenly bedded interlayered 

white sand and thin streaks of clay with a coarse pebble layer at the 

bottom, occur in apparent unconformity (fig. 30) beneath the overburden, and beneath this material is the main clay bed, which has a 

maximum thickness of 18 feet. On the lower slopes of the valleys 

the thickness is less, and from many of the valley bottoms all the 

clay has been eroded. If only one-third the acreage is underlain 

by clay, the reserve is over 3,000,000 tons. Below the clay there is 

coarse gritty sand of unknown thickness.

Two grades of crushed clay are marketed. A pulverizer run by 

electric power has been installed in one end of the dry shed, so that 

in the future pulverized clay will also be furnished. The No. 1 

clay is a white, very finely granular, brittle material made up mainly 

of tiny flecks of kaolinite not over 0.004 millimeter in diameter. In 

addition there is very little decomposed mica in grains of the same 

dimensions, and a few grains of zircon and possibly tourmaline, as
SEDIMENTARY CLAYS. 169

well as numerous tiny grains of rutile. Besides the fine grains of 

kaolinite there are many larger flakes about 0.02 millimeter in diameter, a few that measure 0.15 millimeter, and some wormlike aggregates of the same minerals. There is no grit.

No. 2 clay is cream colored. It differs from No. 1 mineralogically 

in containing a greater abundance of mica and a few diatoms that 

may have been accidentally introduced.

The McNamee clay slakes rapidly, forms a slightly creamy, viscous 

mass with water, and settles very slowly, forming a smooth, almost 

structureless precipitate. An analysis is given on page 168. Commercial analyses show very little difference between grade No. 1 and grade 

No. 2.

In mining the overburden is removed by steam shovel and hauled 

to the dump in the valley below the pit. The clay after removal from 

the pit is dried and then sent by a narrow-gage road to Bath, where 

it is transferred to the Southern Railway. It is expected soon to 

change the spur to a standard-gage road and to haul to the main 

line by electricity.

The present capacity of the plant is about 15,000 tons annually. 

With abundant labor the output could be increased to 30,000 tons, and 

by working a night shift it could be increased still further. The mine 

is not able to supply the demand for its product, and consequently 

steps are being taken to enlarge its working capital, so that its output 

can be raised to 100,000 tons a year.

The following tests of a sample of white clay from the pit of the 

McNamee Clay Co. have been supplied by the laboratory of the 

Bureau of Mines at Columbus, Ohio. The sample (Bureau of Mines' 

No. 1.65) represents a mixture of several clays.

General physical tests of sample of clay from pit of McNamee Clay Co., Bath, 

S. C. (Bureau of Mines No. 1.65).

Workability______Very plastic; makes good bars; cracks some. 

Water of plasticity, in terms of dry clay____!___per cent_ 43.4 

Air shrinkage by volume_ _______________do__ 22. 54 

Air shrinkage, linear, calculated____________do__ 8.20

Fire tests of sample of clay from pit of McNamee Clay Co., Bath, S. C. (Bureau

of Mines No. 1.6J5).

Temperature (°C.).

1,190.............................

1,250.............................

1.310.............................

1,370.............................

1,410.............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

40.97 

38.70

31.20

22.20

9.81

 

Color.

White.................................

.....do................................

.....do................................

.....do................................

.....do................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

22.65 

25.30 

32.40 

41.70 

45.37

Linear shrinkage, calculated (per 

cent).

8.2 

9.3 

12.2 

16.5 

18.3

Cone of fusion, 33.
170 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

A sample of this clay was used in a porcelain .body and gave the 

results noted below:

General physical tests of porcelain body containing clay of sample No. 1.65.

c

Workability ___________Plastic; made good bars and bats. 

Water of plasticity, in terms of dry clay_____per cent 34.31 

Volume shrinkage________,______:____do__ 18.18 

Air shrinkage, linear, calculated___________do__, 6. 5 

Modulus of rupture________pounds per square inch_ 137.9

Fire tests of porcelain body containing clay of sample No. 1.65.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

25.3 

28.87

23.12 

4.69

.40

Color.

White.................................

.....do................................

.....do................................

.....do................................

.Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

20.20 

21.12 

21.89 

35.42 

36.50

Linear shrinkage, calculated (per 

cent).

7.3 

7.6 

7.9 

12.6 

14.1

Modulus 

of rupture 

(pounds 

per 

square 

inch).

2,833 

4.775 

4,044 

5,243 

8,640

The following tests of a second sample of white clay (Bureau of 

Mines No. 1.66) from the same pit gave the results noted below:

General physical tests of sample of clay from pit of McNamee Clay Co., Bath, 

S. C. (Bureau of Mines No. 1.66).

Workability.____ Good; fat; makes good bars; cracks slightly. 

Water of plasticity, in terms of dry clay_______per cent 34.41 

Air shrinkage by volume__________________do__ 12. 86 

Air shrinkage, linear, calculated____________do__ 4.5

Fire tests of sample of clay from pit of McNamee Clay Co., Bath, 8. C. (Bureau

of Mines No. 1.66).

Temperature (°C.).

i ion

1,250.....................:.......

1,310.............................

1,370..............................

1,410.............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

36.70

34.50

27.32

34.20

13.10

Color.

White................................. .....do.. .. ............................

.....do................................

.....do................................

.....do................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

21.60

24.40

29.29

35.10

41.30

Linear shrinkage, calculated (per 

cent).

7.8

8.9

10.9

13.4

16.3

Cone of fusion, 32$.

A sample of this clay was used in a porcelain body and gave the 

following results:
SEDIMENTARY CLAYS. 171

General physical tests of porcelain body containing clay of sample No. 1.66.

Workability________ Plastic, molded well; good in jiggering. 

Water of plasticity, in terms of dry clay____per cent__ 27.52 

Volume shrinkage____________________do__ 14.66 

Air shrinkage, linear, calculated____________do__ 5.2 

Modulus of rupture________-pounds per square inch_ 187.9

Fire tests of porcelain body containing clay of sample No. 1.66.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

24.2 

23.62

20.39

5.11

.20

Color.

White.................................

.....do................................

.....do................................

.....do................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

18.7 

20.06 

22.89 

30.30 

33.50

Linear shrinkage, calculated ( per 

cent).

6.7 

7.2 

8.3 

11.3 

12.7

Modulus 

of rupture 

(pounds 

per 

square 

inch).

1,552 

4,774 

3,639 

5,415 

8,823

The McNamee product has a very wide use as a paper clay, not 

only for wall paper, in the manufacture of which it enters as filler, 

for coating, and for top printing, but also for high-grade print 

papers and cardboard. It is somewhat more transparent and a little 

darker than English clay, and therefore is usually mixed with the 

imported material when intended to be used for coating. However, 

some manufacturers employ it alone for coating cheaper stock, and 

many employ it alone or mixed with other domestic clays or with 

talc as a filler for manila and newsprint paper and to some extent 

for high-grade book and magazine papers. In this field it has 

replaced imported china clays to a large extent. Some lithographic 

paper coated with a mixture of talc and MoNamee clay is satisfactory 

for many purposes, though not of as high grade as paper coated 

with a mixture in which some English clay has been added.

In making pottery the record of the McNamee clay is almost 

equally good. It is used by some potters in the manufacture of 

electrical and chemical porcelain, hotel china, and china door knobs 

in a mixture in which there is no imported clay. To this extent it 

replaces the imported article and has been substituted for English 

china clay with success in the manufacture of floor tile. Another 

important use of the clay is in the manufacture of the medicinal 

preparation known as antiphlogistine.

LANGLEY, AIKEN COUNTY.

Property of the' South Carolina Clay Co. The South Carolina 

Clay Co. is another long-established corporation in this part of the 

State. Its main office is in West Chester, Pa. The property consists 

of about 400 acres about 2 miles south of Langley, all of which is

77412 22 13
172 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Soil

White sand

Red sand and clay 

Red sand

White sand and thin 

clay seams .

Coarse white sand 

and lenses of clay, 

current-bedded

White clay, buff at top

believed to be underlain by clay. About 15 or 20 acres have been 

bored. The thickness of the clay bed ranges from 4 to 22 feet, 

depending upon the topography, and that of the overburden from 

30 to 55 feet. The total quantity of clay in the 20 acres is about 

700,000 tons, of which 20,000 tons are uncovered in the pit. The total 

reserve in the 400 acres is estimated to be over 10,000,000 tons, but 

how much of it is available under present conditions of working is 

not known.

In places the walls of the pit expose excellent sections, of which 

a typical one is shown in figure 31. In some places the cross-bedded 

_ coarse white sand with clay lenses becomes a distinct clay conglomerate 

from 3 to 18 feet thick, in which the 

"pebbles" are little round nodules of 

clay.

The upper part of the clay bed is 

commonly a buff or badly stained reddish clay that ranges in thickness from 

5 to 20 feet. Under this clay is in most 

places a little sand and beneath this 

sand the commercial white clay. 

Where the colored clay is thickest the 

white clay is thinnest and vice, versa.

Only one grade of clay is shipped, but 

this is in two sizes crushed and pulverized. The clay is dense or extremely 

fine grained and brittle, and it contains 

almost no grit. The kaolinite is in 

flakes and shreds, most of them very small, though some are fairly 

large. The small flakes measure about 0.004 millimeter in diameter, 

and some of the large flakes as much as 0.05 millimeter. Perhaps the 

average size of the large grains is 0.035 millimeter. Besides kaolinite 

there are a few flakes of muscovite, 0.05 millimeter in diameter, and 

many small shreds 0.01 millimeter in length. Grains of titanite and 

rutile are comparatively numerous, and here and there are scattered 

grains of zircon. When mixed with an excess of water the clay slakes 

rapidly, forming a mixture which is very pale cream-colored. From 

this solution the clay settles rapidly as a slightly flocculent sediment. 

The overburden is removed by a drag scraper. The clay is dried 

and sacked and- is hauled over a narrow-gage road to the shipping 

point at Langley, on the Southern Railway.

The present capacity of the plant is 600 tons monthly, but this can 

be increased to 700 tons with sufficient labor and to 3,000 tons by 

working a night shift with the new pulverizer just installed. The 

plant can supply clay pulverized either to 200 or 300 mesh.

Vertical scale 

0 is Feet

FIGURE 31. Section in pit of 

South Carolina Clay Co.j, south 

of Langley, S. C.
SEDIMENTARY CLAYS. 173

The following tests of a sample of white clay (Bureau of Mines, 

No. 1.18) from the pit of the South Carolina Clay Co. have been 

supplied by the laboratory of the Bureau of Mines at Columbus, 

Ohio:

General physical tests of sample of clay from pit of South Carolina Clay Co.

at Langley, S. C.

Workability___ Fairly fat; makes good bars; dries fairly well. 

Water of plasticity, in terms of dry clay______per cent__ 39. 61 

Air shrinkage, by volume_________________do__ 15. 83 

Air shrinkage, linear, calculated__________ _do_ 5. 60

Fire tests of sample of clay from pit of South Carolina Clay Co., Langley, S. C.

Temperature (°C.).

1.190.............................

1,250.............................

1,310.............................

1,370.............................

1,410.............................

Porosity 

(per cent 

in terms 

of volume 

of burned

clay).

38.17 

34.20

32:67

24.25

12.50

Color.

White.................................

.....do................................

.....do................................

.....do................................

.....do................................

Volume 

shrinkage 

(percent 

in terms 

of volume 

of dry 

clay).

22.21 

27.00 

32.20 

36.87 

44.20

Linear shrinkage, calculated (per

cent).

8.1 

10.0 

12.2 

14.2 

17.7

Cone of fusion, 34.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain tody containing clay from pit of South 

Carolina Clay Co., Langley, S. C.

Workability_______ Plastic; molded well; fair jiggering body ;

good drying qualities. . Water of plasticity, in terms of dry clay_____per cent_ 33. 95 

Volume shrinkage ___________:________do____ 22.60 

Air shrinkage, linear, calculated____________do_-!__ 8.20 

Modulus of rupture________pounds per square inch 167. 30

Fire tests of porcelain ~botf,y containing clay from pit of South Carolina Clay

Co., Langley, S. C.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

25.60

24.03

18.8*

1.01

.10

Color.

White................................. .....do............................:...

.....do................................

.....do................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

20.10

21.43

22.88

33.90

35.30

Linear 

shrinkage, calculated (per 

cent).

7.2

7.7

8.3

12.9

13.6

Modulus 

of rupture 

(pounds 

per 

square 

inch).

3,323

3,709

3,881

7,788

7,383
174 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

This clay is used for a great variety of purposes. It is employed 

for coating and top-printing wall paper and as a filler in cheap 

print paper, and for both purposes it has entirely supplanted the 

English china clay that was formerly used to some extent. It is also 

used for coating book papers, but as a rule only in mixtures with 

English clays. It forms part of the mixture from which crayons 

and pencil leads are manufactured, and for this use it appears to be 

better than the English clay. It is also used alone or in mixtures 

employed as filling materials in paint compositions and in the manufacture of lakes for aniline dyes, though it is not white enough for 

white pigments. Some potters state that it has entirely replaced the

foreign clay that was 

once used in making 

glazed wall tile and vitree sand and gray OUS floor tile, and it is

 / 4. u jj j u-t , ters as a substitute for

 : .-. .Current-bedded white sand

' ' with streaks and lenses other HI 0 T 6 6.X p 6 n S i V 6 

or white and drab clay china clays in the manu-

/f^^gr^j:^^^^ Drab clay facture of semiporcelain 

jJZ^i^^.-^. H^Hif . w a r e. In the porcelain

/~:_r-_rT -; .-.-'-Sandy white clay . . , ... j-^- :-r -. - -j-_ ' ' mixture, however, it is 

,-_- - ~~=:F- ''~~ ,., , employed in small quan-

/. -=^r - -=-±- Dense white clay .,. , , . .

/ - L -r^pJ^-r^.- _- titles only; but ex pen-

]EF - ~ ~ ments are now being made

30Feet in the expectation that it

1 ' ' ' mav be so used in larger FIGURE 32. Section in pit of Paragon Kaolin Co., J . . e 

south of Langley, S. C. quantities.

Property of the Paragon Kaolin Co. The Paragon Kaolin Co., 

whose office is at Langley, S. C., has been operating the same pit for 

about 35 years. It is about 2 miles south of Langley and about threefourths of a mile west of the Peerless mine. The property consists 

of 234 acres held in fee and the mineral rights on 50 acres more. 

Borings indicate the presence of clay 12 feet in average thickness 

under the entire acreage. Based on these data the tonnage in reserve 

is about 6,500,000.

The general section in the pit is shown in figure 32.

An unconformity, between the drab clay and the white sand is 

shown in an old pit near by. (See PI. XII, A.)

Only crude clay is now being shipped, and this is mainly of one 

grade, which is nearly white and very finely granular. When mixed 

with water it forms a viscous mass, from which the clay settles 

slowly as a structureless precipitate. Under the microscope the 

kaolin is seen to differ very little from that of the McNamee and 

Peerless pits. The greater portion of the kaolinite is in little flakes
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XII

A. UNCONFORMITY BETWEEN DRAB CLAY AND WHITE SAND IN PIT OF 

PARAGON CLAY CO., LANGLEY, S. C.

B. PIT OF PEERLESS CLAY CO., SOUTH OF LANGLEY, S. C.
SEDIMENTARY CLAYS. 175

about 0.004 millimeter in diameter, but there are present also a great 

many flakes from 0.03 to 0.05 millimeter in diameter and a comparatively large number of the wormlike aggregates. Mica is scarce. 

Grade No. 2 is furnished only on special orders.

The active pits are kept dry by pumping. The overburden, which 

ranges in thickness from a few feet to 50 feet, is removed by shovels 

and carts. The dried clay is sacked and hauled by a narrow-gage 

road to the Southern Railway at Langley for shipment.

In the near future it is expected that the overburden will be 

stripped by steam shovel and hauled away in dump cars by a dummy 

engine.

The production is about 600 tons monthly. When improved machinery is installed the output should be increased materially.

The following tests of a sample of white clay (Bureau of Mines 

No. 1.2)' from the pit of the Paragon Kaolin Co. have been supplied

by the laboratory of the Bureau of Mines, at Columbus, Ohio:

General physical tests of sample of clay from pit of Paragon Kaolin Co., 

Langley, 8. C. (Bureau of Mines No. 1.2).

Workability___________ Fairly plastic,; makes good bars. 

Water of plasticity, in terms of dry clay _ per cent 35. 20 

Air shrinkage by volume__________________do__ 18. 67 

Air shrinkage, linear, calculated___ _______do__ 6. 70

Fire tests of sample of clay from pit of Paragon Kaolin Co., Langley, S. C. 

(Bureau of Mines No. 1.2).

Temperature (°C.).

1,250..................:...........

1,310..............................

1,370..............................

1,410..............................

Porosity 

(per cent 

in terms 

ol volume 

of burned 

clay).

34.76 

31.00

29.63

26.21

14.30

Color.

White..................................

.....do.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(percent 

in terms 

of volume 

of dry 

clay).

21.47 

22.44 

28.49 

32.12 

37.80

Linear shrinkage, calculated (per 

cent)

7.8 

8.1 

10.6 

12.2 

14.7

Cone of fusion, 34.

A sample of this clay was used in a porcelain body and gave the 

results noted below: .

General physical tests of porcelain ~body containing clay of sample No. 1.2.

Workability__________________ Good drying properties. 

Water of plasticity, in terms of dry clay______per cent 27. 92 

Volume shrinkage____________________do__ 16. 63 

Air shrinkage, linear, calculated _____ _do 5. 9 

Modulus of rupture--___ pounds per square inch 155.4
176 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

Fire tests of porcelain body containing clay of sample No. 1.2.

Temperature (°C.).

1,190...................

1,250............ ......

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

26.3 

24.53

21.37

8.87 

.20

Color.

White. ................................

.....do................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

16.10 

17.59 

19.54 

27.51 

32.50

Linear shrinkage, calculated (per 

cent).

5.7 

6.3 

7.0 

10.2 

12.3

Modulus 

of rupture 

(pounds 

per 

square 

inch).

2,646 

2,690 

4,199 

4,523 

5,812

A second sample of white clay (Bureau of Mines No. 1.21) from 

the same pit showed the following properties:

\

General physical tests of sample of clay from pit of Paragon Kaolin Co., 

Langley, S. C. ABureau of Mines No. 1.21).

Workability____ _ __ Fairly plastic; makes fine bars. 

Water of plasticity, in terms of dry clay____per cent_ 36.10 

Air shrinkage, by volume _____________do__ 16.64 

Air shrinkage, linear, calculated___________do__ 5.90

Fire tests of sample of clay from pit of Paragon Kaolin Co., Langley, 8. C. 

(Bureau of Mines No. 1.21).

Temperature (°C.).

1,190..............................

1,250..............................

1,310..............................

1,370..............................

1,410..............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

34.45

31.60

29.62

. 20.20

7.90

Color.

White.. .............. v................

.....do.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

23.13

25.80

30.07

iz 3

40 c

Linear shrinkage, calculated (per 

cent).

8.4

4.5

11.3

13.6

17.4

Cone of fusion, 34.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain body containing clay of sample No. 1.21.

Workability ______ Plastic and smooth; makes excellent bars;-

jiggers well ; dries well.

Water of plasticity, in terms of dry clay ____ per cent__ 28. 51 

Volume shrinkage ______________ do __ 15. 61 

Air shrinkage, linear, calculated ___________ do __ 5. 50 

Modulus of rupture _______ pounds per square inch _ 193.8
SEDIMENTARY CLAYS. 177 

Fire tests of sample of clay from pit of Paragon Kaolm Co., Langley, 8. C.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of turned 

clay).

24.50 

23.29

20.20

4.87 

.35

Color.

White.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

18.60 

20.79 

20.81 

30.11 

32.18

Linear shrinkage, calculated (per 

cent).

6.7 

7.5 

7.5 

11.3 

12.2

Modulus 

of rupture 

(pounds 

per 

square 

inch).

3,044 

3,850 

4,689 

5,780 

6,546

The clay from the Paragon mine is used with success as a filler 

for manila paper, for this purpose replacing foreign clay, and wall 

paper. It is also used in coating and top printing wall paper. An 

extensive use is as a filler for high-grade calendered paper, such as is

employed in the best magazines and in illustrated catalogues.

Property of the Peerless Clay Co. The Peerless Clay Co. is another comparatively old organization. Its plant is 2 miles south of 

Langley and about one-quarter of a mile north of that of the Immaculate Kaolin Co. Its pit is extensive and covers several acres. 

(See PI. XII, B.) The company states that borings over 200 acres 

have shown good clay underlying the entire area with a thickness 

ranging from 8 to 15 feet. On the assumption that the average 

thickness is 12 feet and that 80 per cent of the clay is merchantable, 

the reserve is estimated to be over 4,000,000 tons. The overburden, 

7 to 20 feet thick, consists of sand and of sand and clay interlayered. 

The clay bed has very much the same characteristics as that at the 

Immaculate pit (p. 182), except that here and there through it are 

scattered lenses of pink clay, sand pockets, and spots of ocher which 

must be removed in mining. In places near the bottom of the bed 

are masses of black, probably carbonaceous clay that also must be discarded. The quantity of these objectionable materials present is not 

known.

The product is supplied in two grades and in two conditions 

crushed and pulverized. No. 1 clay is a white, smooth, slightly 

granular clay, composed almost exclusively of tiny grains of kaolinite, few of which are more than 0.004 millimeter in diameter. There 

are a few highly refracting wisps of a colorless mineral that is probably muscovite and a very few brown grains that are believed to be 

rutile. The clay slakes easily and forms a very pale cream-colored 

viscous mass, from which the clay settles very slowly as an almost 

structureless sediment. No. 2 clay is light cream-colored and slightly 

gritty, through the presence of a few quartz grains. It contains a 

little more mica than No. 1, but otherwise the two grades are similar.
178 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

An analysis of a sample of No. 1 clay, made by H. H. Graver, of the 

Pittsburgh Testing Laboratory, gave the results shown in the first 

column of the table below. In the second column is given the analysis published by Sloan.

Analyses of clay from pit of Peerless Clay Co. near Langley, S. C.

Silica (SlOj)-..................-.....................................................

Alumina (AljOj) ...................................................................

Lime (CaO) . ........................................................................

Magnesia (MgO) ....................................................................

Soda(NajO).......:................................................................

Potash (KZO).......................................................................

Titanium oxide. ................................................................:...

Water (HjO)..... ...................................................................

lo

44.00

40.25

1.43

28

Trace.

} .40

1.50

12.14

100.00

2

44.66

37.90

2.53

.08

Trace.

/ - 41

1 .36

1.29

13.17

100. 40

a In this analysis the iron is given as iron oxide, and the water, which was determined by difference, is 

reported as combined water.

1. Pittsburgh Testing Laboratory. H.H. Graver, analyst.

2. Sloan, Earle, South Carolina Geol. Survey, ser. 4, Bull. 1 (Reports and Resolutions, vol. 2), p. 863,1904.

The overburden is removed by a drag excavator. The clay after 

drying is crushed and pulverized. Shipment is made in standard 

cars on a spur of the Southern Railway that joins the main line at 

Langley. 

The present output of the plant is about 1,200 tons monthly, but 

with abundant labor this could be increased to 3,000 tons, without 

working a night shift.

Four samples of clay from this company's pit were tested at the 

laboratory of the Bureau of Mines at Columbus, Ohio, and the results 

are given below:

General physical tests of sample of clay from pit of Peerless Clay Co., Langley,

S. C. (Burem of Mines No. 1.15).

Workability _ ____________ Very plastic; makes good bars.

Air shrinkage by volume _____________per cent 31. 61 

Air shrinkage, linear, calculated____________do__ 11. 90

Fire tests of sample of clay from> pit of Peerless Clay Co., Langley, S. C. (Bureau

of Mines No. 1.15).

Temperature (°C.).

1,190.............................

1,250...............'..............

1,310.............................

1,370.............................

1.410.............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

% clay).

39.23 

30.40 

.80 

2.10 

1.20

Color.

jwhite; very faint tinge of light buff. . .

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

/ 30.01 

\ 39. 10 

55.90 

55.54 

53.50

Linear shrinkaee, calculated (per 

cent).

11.3 

15.2 

23,9 

23.7 

22 5

Cone of fusion, 34$.
SEDIMENTARY CLAYS. 179

A sample of this clay was used in a porcelain body and gave the 

following results:

General physical tests of porcelain body containing clay of sample No. 1J5.

Workability__ Very plastic and smooth; makes excellent bars; 

jiggers well; smooth and hard when it dries well. 

Water of plasticity, in terms of dry clay____ per* cent 35.37 

Volume shrinkage_____________________do__ 22. 43 

Air shrinkage, linear, calculated____,______do__ 8.20 

Modulus of rupture_________pounds per square inch__ 250. 20

Fire tests of .porcelain body containing clay of sample No. 1.15.

Temperature (°C.).

1 ion

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms' 

of volume 

of burned 

Clay).

19.00 

17 40

8.49 

.51 

.30

Color.

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

. clay).

29.00 

29.98 

28.06 

40.40 

35.60

Linear shrinkage, calculated (per 

cent).

10.40 

11.20 

1'0.40 

15.80 

13.60

Modulus 

of rupture 

(pounds 

per 

square 

inch).

1,493 

935 

2,317 

4,258 

4,282

General physical tests of sample of clay from pit of Peerless Clay Co., Langley 

8. C. (Bureau of Mines No. 1.16).

Workability______Fairly plastic; makes fair bars; dries well. 

Water of plasticity, in terms of dry clay___per cent__ 42. 20 

Air shrinkage by volume______________do____ 17.65 

Air shrinkage, linear, calculated__________do___ 6. 30

Fire tests of sample of clay from pit of Peerless Clay Co., Langley, S. C., 

(Bureau of Mines No. 1.16).

Temperature (°C.).

1,190.............................

1,250............................. 

1,310.............................

1,370............................. 

1,410.............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

. 37.60 

32.90 

23.18 

14.20 

6.10

Color.

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

i

22.65 

28.50 

37.60 

42.90 

46.00

Linear shrinkage, calculated (per 

cent).

8.2 

18.6 

14.5 

17.0 

18.6

Cone of fusion, 33.

A sample of this clay was used in a porcelain body and gave the 

results noted below: , 

General physical tests of porcelain body containing clay of sample No. 1.16.

Workability__Works well; very good jiggered body; dries well. 

Water of plasticity, in terms of dry clay___per cent__ 28. 31 

Volume shrinkage___________ _____do_- _ 15. 52 

Air shrinkage, linear, calculated_________do___ 5. 50 

Modulus of rupture___.. _pounds per square inch__ 345. 20
180 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Fire tests of porcelain body containing clay of sample No. 1.16.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay). 

o

22.70 

20.51 

15.18 

.40 

.20

Color.

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

I 20. 30 

\ 23. 05 

1 27. 64 

34.36 

33.00

Linear shrinkage, calculated (per 

cent).

7.3 

8.4 

10.2 

13.1 

12.5

Modulus 

of rupture 

(pounds 

per 

square 

inch).

3,921 

3,259 

3,820 

8,030 

6,844

General physical tests of sample of clay from pit of Peerless Clay Co., Langley, 

S. C. (Bureau of Mines No. 1.17).

Workability_____Very plastic; makes good bars; cracks badly. 

Water of plasticity, in terms of dry clay_____per cent 56.25 

Air shrinkage by volume_________________do__ 25.80 

Air shrinkage, linear, calculated __________do__ 9.50

Fire tests of sample of clay from pit of Peerless Clay Co., Langley, 8. C. (Bureau

of Mines No. 1.17).

Temperature (°C.).

1,190...............................

1,250..............................

1,310..............................

1,370..............................

1,410..............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

28.80 

22.80 

2.03 

3.22

2.50

Color.

.....do..................:..............

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

39. 10 

46.70 

55.50 

54.37 

56.00

Linear shrinkage, calculated (per 

cent).

15.3 

18.9 

23.6 

22.0 

23.9

A sample of this clay was used in a porcelain body and gave the 

results noted below: 0

General physical tests Of porcelain body containing clay of sample No. 1.17.

Workability_____________ Very plastic; makes good bars;

jiggers well; dries nicely.

Water of plasticity, in terms of dry clay_____per cent_ 36.20 

Volume shrinkage ____________________do__ 22.88 

Air shrinkage, linear, calculated____________do__ 8. 30 

Modulus of rupture_____ _pounds per square inch__ 161. 50

, Fire tests of porcelain body containing clay of sample No. 1.17.

Temperature (°C.).

1,190...................

1,250................... 

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

19.30 

17.90 

12.22 

.37 

.30

Color.

^live-win. ... ... .,.,.. , . .

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

f 28.00 

\ 28.70 

32.26 

39.89 

38.70

Linear shrinkage, calculated (per 

cent).

10.4 

10.7 

12.2 

15.6 

15.0

Modulus 

of rupture 

(pounds 

per 

square 

inch).

807 

4,069 

2,821 

4,229 

3,683
SEDIMENTARY CLAYS. 181

General physical tests of sample of clay from pit of Peerless Clay Co., Langley, 

8. C. (Bureau of Mines No. 1.19).

Workability Fairly fat; makes good bars; cracks badly. 

Water of plasticity, in terms of dry clay_____per cent 52.27 

Air shrinkage by volume __________,__do__ 23.78 

Air shrinkage, linear, calculated____________do__ 8.70

Fire tests of sample of clay from pit of Peerless Clay Co., Langley, S. C. (Bureau

of Mines No. 1.19).

Temperature (°C.).

i ion

1,250..............................

1,310..............................

1,370..............................

1,410..............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

38.10 

32.50

13.10

3.77 

2.20

Color.

.....do.................................

.....do.................................

Volume 

shrinkage 

(percent 

in terms 

of volume 

of dry 

clay).

27.00 

37.20 

48.50 

52.66 

54.50

Linear shrinkage, calculated (per 

cent).

10.0 

14.4 

17.3 

22.1 

23.1

Cone of fusion, 34.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain body containing clay of sample No. 1.19.

Workability_Fairly plastic; makes good bars; fair jiggering quality. 

Water of plasticity, in terms of dry clay____per cent_ 37.04 

Volume of shrinkage__________________do__ 22.24 

Air shrinkage, linear, calculated___________do__ 8.1 

Modulus of rupture_______pounds per square inch 160.0

Fire tests of porcelain body containing clay of sample N.o\ 1.19.

Temperature (°C.).

1,190...................

1,250...................

1,310 ..................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

' clay).

22.60 

21.17

14.08

.51 

.20

Color.

Very light buff........................

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

25.70 

27.19 

31.69 

38.75 

38.20

Linear shrinkage, calculated (per 

cent).

9.4 

10.1 

11.9 

15.1 

14.9

Modulus 

of rupture 

(pounds 

per 

square 

inch).

3,912 

4,022 

6,277 

9,711 

5,853

The clay from this pit has been used as a filler in high-grade print 

paper and in cardboard and for coating high-grade book paper. 

Some manufacturers declare that it is replacing English clay in their 

works, but others express regret that they are unable to use it except 

in small quantity. It is employed in cold-water paints, and to some 

extent as an inert pigment in oil paints and in some brands of 

cement mixtures. It is also used as filler and in coating and topprinting wall papers and for producing a hard, smooth finish on 

certain brands of roofing material.
182 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Property of the Immaculate Kaolin Co. The pit of the Immaculate Kaolin Co. is about 2£ miles southeast of Langley. The main 

office is in Easton, Pa.

Shipments have been made from the property during the past 

24 years without materially diminishing the supply available. Borings have blocked out a five-years' supply ahead, and about 300 acres 

have not been explored. As the clay bed is horizontal and as it outcrops in all the stream valleys and gullies crossing the property, there 

is no reason to doubt that clay of the same general character as that 

now being mined underlies the entire acreage, except in the bottoms 

of the valleys. If this inference is correct, the total reserve must 

be over 6,000,000 tons.

The overburden in the area explored is from 30 to 35 feet thick, 

and the clay bed ranges from 10 to 20 feet in thickness, though the 

general average is 15 feet. The variation in the thickness of the 

clay bed is due partly to variation in the position of the surface, but 

more commonly to undulations in the top of the bed itself.

In the walls of the pit in September, 1918, the beds were exposed 

as follows, beginning at the top:

Section in pit of Immaculate Kaolin Co.

Feet.

Soil _____________________________________ 2 

Bed sand, with layers of limonite in somewhat wavy beds__ 7 

Yellow sand with sparse pebbles and layers of pebbly sand

in lower part____________________________ 20 

White clay with few feet of drab clay on top and scattered 

purple-stained masses______________________ 12

The layers of limonite are much more nearly horizontal than the 

top of the clay, which may indicate that the undulations of the 

upper surface of the clay are due to erosion and that an unconformity 

exists between the clay and the pebbly sand above it. This relation 

is suggested also by the relations of the clay to the overlying sands 

in the neighboring Paragon pit (fig. 32, p. 174).

The clay bed is by no means uniformly pure. Iron rust, pink 

stains, pockets of gravel, and local layers of dark clay necessitate 

careful sorting in the pit. This sorting, however, is readily accomplished, so that the material sent to the driers is uniform in character.

Two distinct grades of clay are produced. No. 1 clay is a smooth, 

pale cream-colored, dense, brittle variety. When mixed with water 

most of it slakes rapidly, breaking down to form a cream-colored, 

thin liquid from which the clay settles rapidly in a loose, flocculent 

mass, but even after several days there remain many soft, flaky 

granules that have not broken down. When finally powdered the
SEDIMENTARY CLAYS. 183

whole mass slakes without leaving a granular residue. The clay 

consists almost exclusively of tiny granules of kaolinite, whose average diameter is 0.004 millimeter, but many of these by clustering 

together give rise to little round clumps which have five or six times 

the diameter of the individual grains. A few larger flakes of 

kaolmite, a few large wisps and a few minute scales of mica, and 

scattered grains of a mineral that is probably rutile are the only 

other constituents noted. Many of the clumps of kaolinite are brownish, suggesting that the tiny flakes of which they are composed are 

slightly surface stained.

No. 2 clay differs from No. 1 only in its color, which is distinctly 

creamy. It acts like No. 1 with water, but the thin slip produced 

is yellowish. The precipitate that settles upon allowing the liquid 

to stand is more flocculent than the precipitate of No. 1 clay, and 

the little granules are more sticky. Under the microscope the principal difference noted between the two grades is that the clumps of 

kaolinite in No. 2 are reddish brown, indicating that the granules of 

kaolinite are more deeply stained than those in No. 1. The stain is 

due to iron hydroxide.

Both grades are furnished in lump and pulverized. In addition, 

on special orders, drab clay and a mixture of inferior No. 2 and drab 

are sold to plaster-board and beaver-board manufacturers.

The following tests of a sample of white clay (Bureau of Mines 

No. 1.14) from the pit of the Immaculate Kaolin Co. have been supplied by the laboratory of the Bureau of Mines at Columbus^ Ohio:

General physical tests of sample of clay from pit of Immaculate Kaolin Co.,

Lanaley, S. G.

Workability _Fat; makes good bars; cracks slightly in drying. 

Water of plasticity, in terms of dry clay______per cent 49.09 

Air shrinkage by volume________________do__ 18.94 

Air shrinkage, linear, calculated_______ ___do__ 6. 8

Fire tests of sample of day from pit of Immaculate Kaolin Co., Langley, S. C.

Temperature (°C.).

1,190............................. i 9wi

1,310.............................

1,370.............................

1,410.............................

Porosity 

(percent 

in terms 

of volume 

of burned 

clay).

39.15 

28.70

13.10 

7.93 

2.60

Color.

Volume 

shrinkage 

(percent 

in terms 

of volume 

of dry 

clay).

27.10 

38.20 

48.50 

48.95 

52.80

Linear 

shrinkage, calculated (per 

cent)

10.00 

14.80 

19.80 

20.10 

22.10

Cone of fusion,
184 HIGH-GRADE CLAYS OF THE EASTERN" UNITED STATES.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain body containing clay from pit of Immaculate 

Kaolin Co., Langley, S. C.

Workability____Slightly short; worked fairly well; jiggers well;

dries well; does not crack.

Water of plasticity, in terms of dry clay____per cent 35.43 

Volume shrinkage--__________________do__ 19.31 

Air shrinkage, linear, calculated___________do__ 6.90 

Modulus of rupture _ ____pounds per square inch_ 119.20

Fire tests of porcelain body containing clay from pit of Immaculate Kaolin Co.,

Langley, S. C.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(per cent' 

m terms 

of volume 

of burned 

clay).

22.50 

21.10

16.37

.30

.02

Color.

.....do................................

.....do................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

24.40 

26.50 

28.97 

38.29 

36.50

Linear shrinkage, calculated (per 

cent).

8.9 

9.8 

10.8 

14.9 

14.1

Modulus 

of rupture 

(pounds 

per 

square 

inch).

1,698 

2,435 

2,403 

2,894 

3,589

An analysis of the clay is given on page 168.

In mining the overburden is removed by a cable excavator and 

the clay is mined by hand. After drying the clay is pulverized so 

that 92 per cent is guaranteed to pass a 200-mesh screen.

The clay is shipped over a spur of the Southern Eailway to 

Langley.

The capacity of the plant is about 600 tons monthly. This quantity could easily be raised to 850 tons with abundant labor, and this 

quantity in turn could be nearly doubled by working at night.

The Immaculate clay is used mainly by paper makers,, though it is 

used also to a small extent for giving plasticity to gypsum plasters 

and as a coating finish to flour sacks and other food containers, for 

which purpose it has replaced almost entirely English china clay. 

In the paper trade it is used for nearly all purposes for which clay 

can be used. It is employed as a filler and for coating wall paper, 

as a filler for high-grade printing paper and cardboard, where it has 

supplanted English clay, for coating printing paper either alone 

or mixed with foreign clay, and for coating glazed paper. For coating expensive glazed papers it is usually mixed with English china 

clay, but for the cheaper grades it is used alone, and by some manufacturers is preferred to the imported clay.
SEDIMENTARY CLAYS. 185 

DIXIANA, LEXINGTON COUNTY.

G-eiger property. Mrs. Lizzie B. Geiger, of New Brookland, owns 

79 acres of unexplored land on the Seaboard Air Line Railway, 4 

miles from Dixiana in Lexington County. Several small .pits have 

uncovered a deposit of smooth white clay, the extent of which is 

unknown.

The property is in the area underlain by the Lower Cretaceous 

beds, and the clay has the properties of the clay belonging to those 

beds. It is white, very fine grained, almost structureless, and fairly 

brittle. It slacks rapidly to a thin suspension, from which the clay 

separates rapidly as a very fine, almost structureless precipitate. 

The clay consists almost exclusively of flakes and grains of kaolinite, 

most of which measure approximately 0.003 to 0.004 millimeter in 

diameter., Other pieces are about ten times as great in their dimension, and there are all graduations in size between these extremes. 

A very few tiny grains of quartz and wisps of mica are also present 

and the usual grains of rutile.

TRENTON, EDGEFIELD COUNTY.

Mims property. The Mims p'roperty is on the Dixie Highway, 

about 8 miles southwest of Trenton, S. C., and 12 miles northeast 

of Augusta, Ga. The property consists of about 200 acres, and at 

least 40 acres is underlain by clay. Where the clay comes to the surface it has been cut out by depressions.

There are two wells and a shaft about 150 yards apart in a line, 

a boring 50 feet deep about 50 feet south of the shaft, which is west 

of the wells, and an exposure 100 yards south of the boring. The 

well to the east shows 40 feet of overburden and 3 feet of clay. A 

boring in its bottom passes through 30 feet of clay. The next opening 

to the west passes through 27 feet of overburden and 2 feet of clay, 

and a boring penetrates the clay for a further distance of 18 feet. 

The shaft, which is on lower ground, exposes 6 feet of overburden and 

6 feet of clay, and has been stopped in clay. The boring shows 10 

feet of overburden and more than 6 feet of clay. The overburden is 

sand or sand and clay interlayered. The clay bed ranges in thickness from 6 to 30 feet, and under it is quicksand.

The clay is uniformly finely granular, slightly grayish white, and 

a little gritty. It is chalky in character. It lacks coherence and 

'breaks up between the fingers under very slight pressure, acting very 

much like a washed clay. It consists of small flakes of kaolinite, 

0.004 millimeter in diameter, and tiny grains of the same mineral, 

abundant quartz grains of all sizes, the largest 0.1 millimeter in diameter, a very little altered mica, a few splinters of a mineral that appears to be epidote, and numerous tiny grains of rutile. The clay 

77412 22 14
186 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

slakes very rapidly and forms with water a very smooth mixture 

which has a slight grayish tinge.

In a report made by A. S. Watts in 1917 this clay is said to be 

of a very pale cream color. A 1-inch cube slakes in water in about 

5 minutes. When washed through a 200-mesh sieve a residue of 

quartz and mica amounting to 2.6 per cent of the total is obtained. 

When passed through a 300-mesh sieve the residue amounts to 5.3 

per cent. The product resulting from washing the crude clay is 93 

per cent of the refined clay that will pass 300 mesh. The color of 

the washed product is a little better than that of the crude material, 

.but is not pure white. It is not improved by chemical treatment. 

When burned at cone 10 (1,330° C.) the product is light buff.

Watts concludes that though the clay would not be acceptable for 

porcelain manufacture it should nevertheless be acceptable to paper 

makers, for its working behavior is excellent. He quotes an analysis 

of the crude clay, as follows:

Analysis of clay from pit on Mims property, 8 miles southwest of Trenton, S. C.

Silica (SiO2 )___________________________ __ 58.10 

Alumina (A12O3 )___________________________ 29.79 

Ferric oxide (Fe2O3 )_____~_________________ .11 

Lime (CaO)_____________________________ .40 

Magnesia (MgO)________________________. Trace. 

Soda (Na2O)________________________1__. Trace. 

Potash (K2 0)___________________________ .40 

Titanium oxide (TiO2 )______________________ 1.50 

Water (H2O)___________________________ 9.90

100. 20

In spite of the location of the deposit in an area indicated on the

map (PI. XI) as underlain by crystalline rocks, the character of the 

clay and its occurrence in a bed that seems to be horizontal lead to 

the view that it is a sedimentary deposit. It may be an outlier of 

the Cretaceous deposits or possibly a deposit of much later age. 

Opportunities were not afforded for determining the question of age. 

Water is abundant on the property, and an electric-power line, is 

only 4 miles away. If mining is undertaken the product could be 

carried in trucks 7 miles to Day's siding on the Southern Railway.

USES OF THE CRETACEOUS CLAYS OF SOUTH CAROLINA.

Varieties of day. The sedimentary white clays of the Cretaceous 

of South Carolina are nearly pure, closely resembling kaolinite in 

composition. They contain as a rule only about 5 per cent of impurities, the most common of which is quartz. Subordinate amounts 

of feldspar, mica, pyrite, and other minerals are present, but in the
SEDIMENTARY CLAYS. 187

better grades they are rare. In the clay from some of the pits the 

total amount of components other than clay is less than 1 per cent.

In addition to the white clay some of the pits also yield a product' 

that is slightly yellow or cream-colored or even bright-yellow and 

dark-purple varieties. The yellow and purple varieties are employed 

to a small extent in making cheap paints, but they are not in great 

demand. The cream-colored grade is used for fillers in certain kinds 

of cheap textiles, cardboard, and paper, in the manufacture of colored 

tile and colored hardware porcelain, in making certain grades of electrical porcelain, in top printing wall paper and in making cold-water 

paints. It is also employed as a filler in rubber goods, in oilcloth, and 

in the manufacture of certain kinds of patent roofing.

The white varieties are used for all the purposes enumerated above 

and also for filling print, book, and magazine paper and white cotton 

goods, for coating paper and cardboard, for coating and top printing 

wall paper in light shades, for making white and light colored kalsomine, and in the manufacture of white electrical and chemical porcelain, semiporcelain, china, white ware, and vitreous floor tiling. The 

percentage of the State's output that is used for pottery and tile, 

as compared with the other uses, is small, although it has increased 

since the war began.

Paper. All varieties of the lighter-colored clays are used as fillers 

in wall paper, as the color of the stock, except in high-grade papers, 

is not of great importance. The paper is prepared by first coating 

its surface and is then decorated by printing on this prepared surface'. 

When a very white ground surface is desired some makers prefer to 

use imported clay, but for most wall papers South Carolina clay, 

either alone or mixed with other domestic clays, appears to be satisfactory. The proportion of imported clay used for this purpose is 

gradually diminishing, and if the southern clay were more uniform 

in color that is, if the shipping stock were more carefully selectedit might supplant English clay almost completely. There is some 

complaint that much of the clay contains yellow streaks or is gritty 

and therefore has to be rejected. Washing would probably remove 

at least the grittiness, if not also the other defects. After the paper 

is coated it is decorated by top printing with a mixture of clay and 

pigment. As a rule, aniline compounds which are transparent furnish the color, and the clay serves as the medium and produces opacity. 

The clays of South Carolina are used very widely for top printing 

and give nearly universal satisfaction. That they are not used more 

widely is due to the difficulty of obtaining them promptly.

As a filler for manila and newsprint paper all the clays from South 

Carolina seem to be equally satisfactory. In some factories they are 

being, used in place of English clay that was formerly imported for 

this purpose, but in a few factories English clay has never been used.
188 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

With regard to their use as a filler for book and magazine paper 

the testimony is more conflicting. Some manufacturers use mixtures 

of different clays from South Carolina with some other domestic 

clays in making high-grade calendered book paper, but other manufacturers state that it is necessary to add a considerable quantity of 

English clay to the mixture in order to obtain a whiter stock, and 

still others declare that they can not use domestic clay for book 

papers because it contains too much grit or too large a proportion of 

components that will not float under a slight pressure. This last 

statement evidently applies to the unwashed clay from most of the 

South Carolina mines, for it is repeatedly stated by paper men that 

the pulverized clay would be more satisfactory if it were crushed as 

fine as the English clay or if it were washed so that it might disintegrate more readily. Much of the unwashed clay slakes poorly, 

' leaving considerable material in soft lumps that clogs the screens in 

the paper mills. There is very little grit, but the clogging of the 

screens interferes with the continuous smooth operation of the machinery. The washed clay is broken into its component particles. 

In the filter press these particles are made to cohere, but the compression is not so severe that they cohere so strongly as before washing. When treated with water they readily fall apart, leaving no 

undivided lumps to choke the screens.

The English clay is regarded by most paper makers as superior 

to American clays because of its uniformly high plasticity, its good 

color, its freedom from grit, and the readiness with which it makes a 

paste with water. Some of the clays of South Carolina possess most 

of these properties, but their color is not pure white, and some of 

the most nearly white are hard to mix with water. These last-mentioned clays would be most benefited by washing.

For coating cheap paper and cardboard the white clays of South 

Carolina are widely employed, and many of the makers, particularly 

of cardboard, state that they have no intention of going back to the 

imported clay, although the domestic clay is a little more transparent 

than the foreign material. For coating paper of a better grade the 

clay from this State has replaced entirely the imported clay in some 

mills, but in most of them some English clay is still used in the coating mixtures, and for the best work the imported clay is used exclusively. The principal objection to using more of the domestic clay 

appears to be its color, which is said to be less uniform than that of 

the imported material. Where color is not important, as in very 

cheap glazed paper and in the coarse paper used in making flour 

bags and other food containers, the clay from South Carolina appears to be satisfactory.

Pigments. For making paints the clay must be white, dry, plastic, 

and free from grit. There is some complaint that the clay furnished
SEDIMENTARY CLAYS. 189

by the South Carolina mines contains too much, moisture to be entirely satisfactory. Common requirements are that it shall contain 

not more than 1 per cent of water, and that it shall not leave more 

than 1 per cent of residue on a 350-mesh screen nor contain more than 

3 per cent of still finer grit after passing it. Many of the shipments 

evidently meet these requirements, for a number of the paint makers 

rather widely distributed over the country use clay from South Carolina as an inert pigment to dilute strong colors, to give body to some 

white paints, and to help float heavy opaque pigments and prevent 

their settling in the manufactured paint.

Floor and wall tile. In the manufacture of glazed wall tile and 

vitreous floor tile the clay from South Carolina seems to be widely 

used. Although some large makers of tile state that they can not 

employ it as a substitute, for English clay, others who are still using 

English clay in part declare that they would replace it with domestic 

clay were it not for the uncertainty of shipments from the South. 

Several manufacturers state that clays from South Carolina and 

Florida make up the greater part of their mixture.

Pottery. According to some manufacturers, the domestic clay is 

slowly replacing imported clay for pottery. The eastern potters 

are not so favorably disposed toward the southern clay as the 

western potters, but even in the East it is being used in an everincreasing amount. One obstacle to its larger use appears to be 

difficulty in procuring prompt delivery. A few potters declare that 

they can not use the clay from South Carolina in their formulas, but 

acknowledge that in other formulas it might be satisfactory. However this may be, clay from all the South Carolina mines is being 

used with satisfactory results by many potters in the Ohio Valley 

and in the West and by a few in the East. It has been used with 

success in the mixtures employed in manufacturing vitreous china 

sanitary earthenware, semiporcelain cooking ware, semiporcelain 

toilet ware, dinner ware, and hotel ware. In some potteries it has 

replaced entirely the imported clay formerly used, but in others 

it is mixed with more or less English china clay. The experience 

with reference to porcelain has varied. The clay from South Carolina is used in making chemical porcelain and hard table porcelain, 

but there is complaint that if more than a small quantity is put into 

the mixture the product will not be white. To remedy this defect 

English clay is added. On the other hand, at least one firm uses 

only domestic clay in its mixture and produces an excelle.nt chemical porcelain, the other ingredients being clays from other domestic sources in addition, of course, to the flint and feldspar that are 

invariably used. A mixture of domestic clays, of which a large 

proportion consists of clay from South Carolina, is also used in 

making electrical porcelain and hotel china.
190 HIGH-GRADE CLAYS OF 'THE EASTERN UNITED STATES.

Filler. Considerable quantities of the white clay from this State 

are used in the process of starching and filling low-priced cotton ticking, and for this purpose it is equally as good as the imported china 

clay that it has replaced. It is also employed as a filler for linoleum, 

wall fabrics, and window-shade cloth. For these purposes the clay 

must be plastic, and this quality the clay from South Carolina possesses to a satisfactory degree. For filling window-shade cloth, however, it is not so good as the imported clay because of its greater 

translucency and yellowish tinge and because it contains as a rule 

too much grit when used without thorough washing. Consequently, 

when employed for this purpose, more or less English clay is always 

mixed with it.

Miscellaneous uses. Besides the purposes already mentioned the 

clays of South Carolina are employed for a great many other purposes but not in as great quantities. They are mixed with washed 

clays from other sources and made into kalsomine or cold-water 

paint, replacing imported china clay. For this purpose the clay must 

meet the same specification in regard to grit as that which is employed 

in paint pigments and must have a slippery surface. In the latter 

respect the clay from 'South Carolina is peculiarly satisfactory, but 

unfortunately it is not as uniformly white as some other domestic 

clays. On the whole, it is regarded by some makers of cold-water 

paints as superior to the imported clay. It is also employed for filtering aniline dyes, in the manufacture of plasters, cements, fireproofing 

materials, and roofing, and is mixed with rubber for molding into 

shaped rubber goods, such as rubber heels.

Because of its binding qualities some of the clay from South Carolina is added to the mixtures from which lumber crayons, school 

crayons, and pencil leads are made. For this purpose it is regarded 

as superior to the foreign clay by some manufacturers.

Some of the clay is employed in making antiphlogistine.

Defects and their remedy. The objections raised by some manufacturers to the broader use of the clays from South Carolina fall 

into five classes (1) objections to color, (2) objections to the presence of yellow streaks, (3) objections to the presence of grit and 

lumps that will not disintegrate, (4) objections to lack of opacity, 

and (5) objections to sizing. The lack of opacity perhaps can not be 

remedied, although some manufacturers believe that it may be counteracted by the use of a small quantity of talc or other opaque substance in the mixture employed. Most of the other defects, however, 

might be reduced, if not removed entirely, by more careful preparation. Only one mine that was visited is provided with apparatus for 

washing the clay. The product of the other mines is said to need 

no washing, as the market' will take all the output in its present 

condition. This is no doubt true at the present time, when, owing to
SEDIMENTABY CLAYS. 191 

»

i- '

the shortage of labor, no mine in the State is working at its full 

capacity. However, washed clay would bring a price enough higher 

than that of the crude clay to pay all the cost of washing and leave 

a good profit besides, so that the present practice of shipping crude 

clay must be regarded as uneconomical.

Careful washing would remove most of the yellow streaks, or so 

break them up that their color would be distributed through the 

mass without affecting it noticeably, and it would eliminate nearly 

all of the grit and cause the whole mass to disintegrate easily on being 

mixed with water. This treatment would improve the clay for filling and coating paper and for filling window-shade cloth and also 

for use in paints. It would benefit the clay to some extent for potters' use, but as the process would remove very little if any of the 

titanium that is found in all the clays from South Carolina they 

could not be used alone in the manufacture of white china, porcelain, 

or semiporcelain.

Most of the critics of the clays from this State insist that their 

grain is neither uniform nor fine enough. Washing would remedy 

both these defects to some extent. Pulverizing carefully would also 

remedy them. Some of the mines are equipped with pulverizers, but 

most of them pulverize to a 200 mesh only. The pulverization could 

be made to a finer mesh without much additional cost, and there 

would be a corresponding improvement in quality. Pulverizing, 

however, does not remove grit or other objectionable ingredients, 

but it may simply crush them finer. This, of course, improves the 

quality of the clay, but a greater improvement would result if the 

objectionable materials could be removed. This removal is accomplished at some of the mines by sizing with fans. The air currents 

generated by the fans carry the finely crushed clay into bags, whereas 

the harder, gritty material, which resists more effectually the crushing process, is left behind. Unfortunately, in some plants the rejected material is carried back into the pulverizer and again crushed 

until nearly all of it finally passes into the bags in which clay is 

shipped. With proper adjustment of the pulverizer and of the fans 

it should be possible to separate the clay from the grit so effectually 

that the undesirable material would be carried out by the air current, and then it could be removed from the bagger and thrown aside, 

instead of being sent back to the pulverizer, as is now done. Several 

mines not now using mechanical baggers contemplate adding them 

to their equipment, and one or two are considering the construction 

of washing plants.

CONDITIONS THAT AFFECT OPERATION.

Location. As the clay beds are nearly horizontal and as their 

character changes very slightly from place to place within short
192 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

distances from one another, their availability for operation depends 

principally upon their nearness to lines of transportation and upon 

their depth beneath the surface; that is, upon the amount of overburden that must be removed before the clay is uncovered.

Most of the operating" mines are either on main lines of railroad or 

are connected with them by short spurs. Other mines are connected 

with the main lines by narrow-gage private roads operated by steam 

or gasoline locomotives and small cars. A few haul their output by 

teams over ordinary country roads. Naturally the producers who can 

ship directly from their plants have an advantage over those that 

must transfer their shipments from narrow-gage cars to those of 

standard gage at points of junction with the main lines of railroad, 

and these in turn are more advantageously situated than those who 

have to haul to the main lines and reload in cars on sidings. The 

companies not on the main lines of traffic must not only handle their 

shipments twice but they must also provide sacks or other receptacles 

in which to carry the material to the shipping points in order to 

reduce the cost of rehandling. Those who haul to the shipping points 

must, in addition, stand the cost of haulage, which, especially in busy 

times, is much greater than the cost of movement by cars. In dull 

seasons, when the movement of the clay is slow, the private lines are 

not much more economical than horses and carts, because of the 

necessity of having high-priced men for train service; but at these 

times the operators on standard-gage railroads, whether main line 

or spurs, are in a particularly favorable situation, for they suffer 

no loss through the idleness of the transportation plant. When the 

cost of loading at the point of shipment is 10 to 12 per cent of the 

price obtained for the product, as it is in some places, it is evident 

that the shipper is seriously handicapped in his attempt to compete 

with others who are not subject to such a charge. Fortunately, at 

the present time the demand for the clay of South Carolina is so 

heavy that competition between the clay miners is a negligible consideration. The great handicaps of the trade during the war were 

lack of labor and lack of cars. In the future, when competition is 

sharper, only those mines will be able to operate successfully that are 

on railroads or near them on good roads that will afford cheap 

haulage by carts or by trucks. A clay bank on a road that will stand 

trucking, however, may be operated at a much greater distance from 

a railroad thanv one on a road that will stand only teaming.

Overburden. The overburden of the sedimentary clays is composed mainly of sand and gravel, together with a little valueless clay 

in some places. Its thickness above the commercial clay differs in 

different localities according to the topography. The area underlain 

by the clay beds is a sloping plain that is dissected by stream valleys.
SEDIMENTABY CLAYS. 193

Its upper surface is about 680 feet above sea level at the fall line, 

and it declines about 20 feet to the mile seaward. Near its western 

margin the clays may reach the surface on the uplands, and there the 

bottoms of the stream valleys are below the clay beds. Where the 

Middendorf clay bed forms the surface, the Lower Cretaceous clay 

may outcrop on the valley slopes or may cover its ^bottom, depending 

upon the depth to which the stream has cut. As the clays dip seaward 

more steeply than the surface of the plain they soon pass beneath 

this surface and are covered by younger sediments that form an 

overburden. Where the streams have cut down to the depth of the 

overburden the clay is exposed in their bottoms, and where the streams 

have cut beneath the bottom of the overburden the clay beds outcrop 

on the valley sides, at about the same elevation on opposite sides and 

throughout the lengths of short valleys, because their dips are so low 

that their departure from the horizontal is scarcely noticeable within 

a short distance. Naturally, most discoveries of the clay beds have 

been made in valleys and most of the clay pits are on or near the 

valley slopes, for in these localities there is little overburden to remove 

before reaching the clay, and the valley furnishes a convenient dumping ground for the material removed.

As the clay bed is followed into the side of the valley the overburden increases in thickness, for the surface of the plain gradually 

rises away from the streams until at the divide between neighboring 

streams its thickness reaches a maximum. In some localities, where 

the clay outcrops at a moderate distance below the surface of the 

plain, the entire area between neighboring streams may be profitably 

worked. In other places the clay bed is so deep beneath the surface 

that it can be worked only around the margins of the valleys. At the 

present time it is not considered profitable to work a bed if the thickness of the overburden is more than about 3| times the thickness of 

the good clay beneath it.

ECONOMIC PROBLEMS.

The two great difficulties with which the South Carolina clay producers have to contend is lack of fuel during periods of freight 

congestion and lack of permanent labor at all times. As fuel is 

used mainly for power production and as the State is rapidly being 

crisscrossed by the transmission lines of hydroelectric companies, the 

problem of securing abundant power will soon be solved for most of 

the mines now being operated.

The labor^problem is more difficult to solve. Most of the labor 

is drawn from the farms, so that it can not be depended upon for 

steady work. In dull seasons it is abundant, but in busy seasons, 

especially during the spring and late summer and autumn, it is unreliable. Wages in 1918 were $1.75 or $2 for a day of 8 hours, which
194 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

was not high enough to attract the ambitious steady workman, and yet 

it was about as high as was practicable, when crushed No. 1 clay 

brought $6.50 or $7 a ton free on board cars. The only remedy for 

these conditions appears to be the installation of more machinery, 

both for saving labor and for the preparation of a higher-grade 

product that will commend a higher price.

Some of the operators are even now trying to solve the problem 

by installing pulverizers of large capacity to take the place of the 

smaller ones now in use, by the substitution of power machines for 

hand labor where it appears advisable, and in other ways they are 

attempting to reduce the man power required to handle their output.

FUTURE DEVELOPMENT OF THE WHITE CLAYS OF SOUTH CAROLINA.

The total amount of high-grade clay in South Carolina in deposits 

that are being developed is about 60,000,000 tons, and the output of 

the mining companies is about 75,000 tons annually. With plenty 

of labor and improved machinery the annual output could easily be 

increased to 125,000 tons. The reserve is therefore sufficient to lasfc 

a long time, even if the rate of production of the mines should stand 

at the higher figure. But only a small portion of the acreage known 

to be underlain by good clay has been explored. If only a small 

part of the unexplored area contains proportionately as great an 

amount of clay as the explored area, the quantity of white clay still 

in the ground is many times greater than the estimated reserve of 

the few mines that are now operating.

The reported production for the last 10 years shows more or less 

fluctuation. The figures for 1915-1918 are as follows:

White. Clay from South Carolina marketed in 1915-1918.

Year.

1915.............................................................................

1916.............................................................................

1917..........................................................:..................

1918.............................................................................

a Estimated. 

GEORGIA.

DISTRIBUTION.

Short tons.

24,688

32.556

40.173

a35,000

Value.

$118,388

168,120

171.506

o230,000

The Lower Cretaceous deposits of Georgia contain the most extensive and valuable beds of clay in that State. Veatch " classes the 

Lower Cretaceous as Tuscalobsa, but it is no longer so regarded. It

77 Veatch, Otto, Second report on the clay deposits of Georgia: Georgia Geol. Survey 

Bull. 18, 1909. Many of the data regarding Georgia have been obtained from this report, 

BUpplemented somewhat b'y a brief visit to the area.
U. S GEOLOGICAL SURVEY BULLETIN 708 PLATE XIII

EXPLANATION

Worked pit 

of white-burning clay 

(Number refers to that

in list Mow)

White-burning clay 

prospect

Refractory clay, white color 

but not in the burning.

LIST OF MINES

1 Albion Kaolin Co.

2 Edgar Bros. Co.

8 Edgar Bros. Co.

4 Kaolin Mining Co.

5 American Kaolin Co.

6 Georgia Kaolin Co.

7 R. H. Jones & Co.

8 Savannah Kaolin Co.

9 Columbia Kaolin & Alumi- 

	num Co.

10 Atlantic Mining & Clay Co.

11 John Sant & Sons Co.

12 Golding Sons Co.

13 Houston Kaolin Co.

MAP OF A PART OF GEORGIA

Showing location of white clay mines and prospects, the latter from Georgia Geological Survey

Scale ~ipoo.oiio

toMUes

10 o 10 20 30 40 50 Kilometer's

1922
SEDIMENTARY CLAYS. 195

forms a belt that extends entirely across the State on the northwestern 

margin of the Coastal Plain, where it is in contact with the crystalline 

rocks. (See PI. XIII.)

The belt of Lower Cretaceous deposits has a maximum breadth of 

50 miles along Chattahoochee River, but to the east, at Ocmulgee 

River, it measures only 20 to 25 miles. East of this river its maximum width is 15 miles, and in places, where it is more or less covered 

by later formations, it disappears.

The irregular width of the belt is due to the uneven nature of the 

surface on which the Lower Cretaceous beds were deposited, in places 

to the overlap or covering by later-deposited formations, and to the 

deep erosion of valleys along certain lines, which have uncovered the 

clays. This explanation accounts for the very irregular southeastern 

border and the tonguelike extensions southeastward, which are 

chiefly along the stream valleys.

In the eastern part of the State the outcrop of the Lower Cretaceous is very much narrower. >

East of Ocmulgee River the Lower Cretaceous is in places obscured 

by the overlying Claiborne sands (Tertiary), which form the overburden in the clay pits. Other still later formations, of gravelly and 

loamy character, overlie the clay in places.

The Lower Cretaceous beds consist entirely of sands, gravels, and 

clays. The thickness of these beds ranges from 500 to 600 feet. In 

the vicinity of Columbus it is 400 feet, in Crawford and Bibb counties 

it is 400 to 600 feet, and east of Ocmulgee River it is from 50 to 600 

feet. The sand consists chiefly of angular quartz, together with 

mica and other minerals. It is generally coarse and cross-bedded 

and makes up about 75 per cent of the deposits.

ORIGIN.

According to Veatch 78 the Lower Cretaceous clays have been derived from the disintegrated and decomposed rocks of the Piedmont 

Plateau and were laid down in fresh water bodies offshore, as in depressions on the surface of deltas or in inland bodies of water.

MODE OF OCCURRENCE.

The clays occur in lenses inclosed by sand, and though these lenses 

are of relatively small extent the clay is of high quality.

Individual lenses range from 1 or 2 feet to 35 feet in thickness, 

and their extent ranges from a hundred yards to several miles. Thus 

it is difficult to estimate the tonnage unless a number of boring 

records are available.

re Veateh. Otto, op. cit.
196 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The clays are more abundant east of Ocmulgee River, and the deposits are also thicker there than elsewhere.

The larger deposits occur in the upper part of the series, or toward 

the southeastern margin of the area as mapped, as shown by the developments around Dry Branch, in Twiggs County, and Mclntyre, in 

Wilkinson County.

The upper boundary of the clay as a rule is sharply separated from 

the overlying Eocene ferruginous sands (PI. XVI), but the lower 

part of the clay grades downward into sand.

In Wilkinson County and also in parts of Washington County the 

white clays in places contain bodies of bauxite, chiefly in the upper 

part of the deposit (PI. XIV, A.)

In some of the deposits also a nodular clay in beds, lenses, or 

irregular masses is associated with the massive white clay. This 

nodular material resembles the clay and not the bauxite in composition.79

STRUCTURE.

The white clays are all massive, and show little stratification. 

Jointing is prominent in some places (PI. XIV, #), but the joints 

follow no well-defined system and may be simply shrinkage cracks. 

In places they are a disadvantage, because they permit the infiltration of iron from the overburden.

Although to the eye the clays may appear equally dense, there is 

nevertheless some variation in this respect, so that some of them slake 

more easily than others..

VARIATION IN THE CLAY.

The white clays appear remarkably uniform, although closer inspection may bring out local variations in any one deposit, or even reveal 

impurities of undesirable character.

The impurities include iron stains along the joints, chiefly in the 

upper part of the deposit; grains or nodules of pyrite, which by 

their decay may give rise to purplish or red mottlings in the clay; 

and quartz sand, generally in the form of scattered grains, thin layers or streaks, but some of it in pockets or in curious finger-like 

masses in the upper 2 or 3 feet of the clay.

If the clay is washed before shipment most of these deleterious 

ingredients can be thus removed, but if the material is sold in its 

crude form, the foreign matter should if possible be avoided or thrown 

out in mining.

' Shearer, H. K., Bauxite and fuller's earth of the Coastal Plain of Georgia: Georgia 

Geol. Survey Bull. 31, 1917.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XIV

A. CLAY BANK OK COLUMBIA KAOLIN & ALUMIMJ-M CO., 4 MILES SOUTH OF

GORDON, GA.

B. JOINTED STRUCTURE IN CLAY SHOWN ABOVE THE TRACK LEVEL IN A.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XV

A. PIT OF GEORGIA KAuLIN CO., NEAR DRY BRANCH, GA. 

White clay lies below track level.

S. PIT OF REPUBLIC MINING & MANUFACTURING CO., EAST OF ANDERSONVILLE, GA.

White clay lies above track level and bauxite below it.
SEDIMENTARY CLAYS. ' 197 

CHEMICAL AND PHYSICAL PROPERTIES.

The better grades of clay show the following range in composition, 

according to Veatch:

Range in composition of better grades of Lower Cretaceous clay from Georgia.

Per cent.

Silica _______________________________ 40-50 

Alumina_______________________________ 34-40 

Ferric oxide_____________.____________0. 51-2.11 

Titanium oxide_____________________ 1. 5-2

A sieve test showed 5 per cent residue on a 200-mesh sieve. The 

clays are mostly.soft, but flinty material may occur. The air shrinkage is usually low. The fire shrinkage is commonly high, and there 

is a tendency to check. The tensile strength is low, mostly 10 to 20 

pounds to the square inch.

The fusion point is generally from cone 30 to cone 36 (1,730° to 

1,850° C.).

MINERALS.

A number of samples of the white clays were examined under the 

microscope. The minerals noted include hydromica, kaolinite, rutile, 

quartz, titanite, zircon, and tourmaline.

No detailed petrographic examination was made of the Lower 

Cretaceous clays of Georgia, but the results obtained from the study 

of a few samples are worth recording.

Sample No. 1. Sample No. 1 is a crude clay from Dry Branch, 

Twiggs County. The clay is fine grained and shows little or no 

quartz. Hydromica is common, and kaolinite is abundant. Rutile 

occurs sparingly. The clay that was fired at 1,150° C. yielded a very 

fine-grained mass in which are some grains that show low interference colors. It showed very little further change at 1,300° C.

Sample No. #. Sample No. 2 is a washed clay from Dry Branch, 

Twiggs County. It is a very fine-grained clay that contains some 

grains of quartz. Hydromica is common and flocculated, and kaolinite is abundant. A few grains of rutile and zircon are present. The 

fired clay shows a fine matted mixture of isotropic grains and others 

that have low interference colors.

Sample No. 3. Sample No. 3 is a crude clay from the upper bed 

in a bank 4 miles south of Gordon, Ga. It is fine to medium grained. 

Quartz grains are fairly common, hydromica is common, and kaolinite is abundant. There are also a. number of indeterminable minute 

dustlike grains. Rutile is scarce.

Sample No. 4- Sample No. 4 is a clay that underlies the clay of 

sample No. 3. It is a nodular white clay, which contains an abundance of very fine indeterminable material that may be colloidal. 

There are a few grains of quartz, some of them sufficiently coarse
198 HIGH-GRADE CLAYS OF THE EASTERN" UNITED STATES.

to be visible to the eye. Kaolinite is scarce, and occurs generally in 

vermiculites. There are also a few grains of zircon and rutile.

OVERBURDEN.

The thickness of the overburden differs from place to place and 

may differ-even in the same pit. This irregularity is due either to 

the unevenness of the upper surface of the clay or of the overburden 

or of both.

As the clay outcrops are most common on the natural slopes, gen: 

erally in the sides of stream valleys, the overburden may be thinnest 

where the clay is exposed and increase as one goes into the hill.

In most of the pits the stripping ranges from 10 to 20 feet in 

thickness, although a's much as 30 to 40 feet is sometimes stripped 

off to work a 20-foot bed of clay. According to some of the sections 

given by Veatch 80 the overburden on some of the deposits now 

being worked may increase to as much as 100 feet.

Sections giving the details of the material constituting the overburden are given by Veatch,81 and by Shearer and Cooke,82 but as 

the material is not utilized economically, it is not necessary to repeat them here.

THE WHITE-CLAY INDUSTRY.

When Veatch wrote his report on the Georgia clays in 1909 he 

remarked that the development of the white clays had hardly begun, 

but to-day they form the basis of a flourishing clay-mining industry.

The chief developments have been in the vicinity of Dry Branch, 

Twiggs County (PI. XV, J.); Gordon, and Mclntyre, Wilkinson 

County (Pis. XIV, 4, and XVI); Hephzibah, Kichmond County; 

and Butler, Taylor County. The map (PI. XIII) shows that these 

localities form two somewhat widely separated groups.

Veatch in 1909 listed the following operations in the Dry Branch 

area: Georgia Kaolin Co., Atlanta Mining & Clay Co., American 

Clay Co., I. Mandle & Co. He also mentioned the Albion Kaolin 

Co. at Hephzibah.

Since that time there have been extensive developments around 

Mclntyre, where the Edgar Bros. Co., of Metuchen, N. J., operates 

two plants (see PI. XVI), and the Kaolin Mining Co., of Philadelphia, Pa., has one at Claymont. Both these companies also have 

washing plants.

At Gordon the Columbia Kaolin & Aluminum Co., of Washington, D. C., and the Savannah Kaolin Co., of New York, N. Y., are 

operating clay pits and washing plants.

80 Veatch, Otto, op. cit., p. 127. 

« Op. cit.

"" Cooke, C. W., and Shearer, H. K., Deposits of Claiborne and Jackson age in Georgia: 

U. S. Geol. Survey Prof. Paper 120, pp. 41-81, 1918.
U. S. GEOLOGICAL SURVEY 

PIT OF EDGAR BROS. CO., NEAR McINTYR

Cross-bedded ferruginous Tertiary sands overlie the Cretac
SEDIMENTARY CLAYS. 199

In the Dry Branch district the companies listed by Veatch are 

still operating, except the firm of I. Handle & Co., which is now 

John Sant & Sons Co. A new operation was started in 1918 by 

R. H. Jones.

At Butler the Golding Sons Co. succeeded the Butler Clay Co., 

and is now operating.

The following tests of a sample of white clay (Bureau of Mines 

No. 1.23) from the top bed in the pit of Golding Sons Co., 2£ miles 

west of Butler, Ga., have been supplied by the laboratory of the 

Bureau of Mines at Columbus, Ohio:

General physical tests of clay from pit of Golding Sons Co., near Butler, Ga. 

Workability _____________Plastic; makes good bars.

Water of plasticity, in terms of dry clay______per cent 44. 3 

Air shrinkage by volume_________________do__ 20. 38 

Air shrinkage, linear, calculated____ __ do_ 7.3

Fire tests of clay from pit of Golding Sons Co., near Butler, Ga.

Temperature (°C.).

1,190.............................

1,250.............................

1,310.............................

1,370.......:.....................

1,410.............................

Porosity 

(percent 

in terms 

of volume 

of burned 

clay).

40.20 

39.30

36.70

27.97

17.80

Color.

White.................................

.....do.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

21.45 

25.60 

28.08 

37.15 

41.80

Linear shrinkage, calculated (per 

cent).

7.8 

9.4 

10.4 

14.4 

16.5

Cone of fusion, 33£.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain body containing clay from pit of Golding 

Sons Co., near Butler, Ga.

Workability-Plastic; makes excellent bars; jiggers well; dries well. 

Water of plasticity, in terms of dry clay_____per cent__ 31. 54 

Modulus of rupture________pounds per square inch_ 132. 6

Fire tests of porcelain body containing clay from pit of Golding Sons Co., near

Butler, Ga.

Tempera ture(°C.).

1,190................... i 9^n

1,310................... 

1,370.........'..........

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

27.80 

25.54 

23.15 

6.09 

.18

Color.

White. ................................

White; slight buff tint. ................

.....do.................................

White.................................

Volume, 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

18.50 

22.59 

22.20 

31.10 

35.60

Linear shrinkage, calculated (per 

cent).

6.6 

8.2 

8.1 

11.7 

13.7

Modulus 

of rupture 

(pounds 

per 

square 

inch).

2,621 

2,418 

3,995 

4,815 

8,203

For a detailed account of the clay deposits of Georgia the reader 

is referred to the report by Veatcli cited above.
200 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

FUTURE EXPANSION.

The clay-mining industry in Georgia may be expanded either by 

increasing the output of the present plants or by opening new 

deposits.

With regard to increasing the output of the plants now in operation, it may be said that in 1918 none of the plants were making full 

production and that all could have increased their output. The total 

daily capacity of the washing plants, according to figures supplied 

by the companies, is between 650 and 700 tons.

As regards hew deposits the accompanying map (PI. XIII) shows 

a number of clay outcrops that are not worked, and no doubt there 

is a considerable reserve, although it can not be stated in terms of 

tonnage.

Some of these unworked deposits are likely to lie idle for a tune 

because of remoteness from railway lines.

USES OF THE WHITE CLAYS OF GEORGIA.

All the white clays mined in Georgia are washed before shipment 

to the market, and the claims of yield of washed product from the 

crude range from 80 to 95 per cent.

Probably most of the refined clay is sold to paper manufacturers, 

who use it as a filler for different grades of paper, some of it even 

in book stock. It is inferior to the English clay in color, but in 

most other respects it is reported to be as satisfactory, and as a 

result it has replaced the English clay,to some extent during the 

war. The clay from Georgia does not seem to be regarded as satisfactory for coating, but a not inconsiderable quantity of it is employed by wall-paper manufacturers for coating and as a base for 

the colors. It is also employed as a filler for shade cloth and has 

been used to replace part of the English clay formerly employed, but 

the use of too large a proportion of it is claimed by some to make 

the cloth too brittle.

In the pottery and tile trades it is used in wall tile, floor tile, sanitary ware, electrical porcelain, semiporcelain tableware, and china. 

One manufacturer of semiporcelain reports that it replaces 25 per 

cent of the English clay that he formerly used.

More recently the Bureau of Standards has used it in glass-pot 

mixtures for making optical glass, and some is being employed by 

New Jersey potters in sagger mixtures.

The marketed production for 1915 to 1918 of white clays from 

Houston, Kichmond, Taylor, Twiggs, and Wilkinson counties was 

as follows:
SEDIMENTARY CLAYS. 201 

White clay marketed in Georgia, 1915-1918.

Year. '

1915.............................................................................

1916......................:......................................................

1917.............................................................................

1918.........:...................................................................

Short tons.

67.752

92.671

109,222

075,000

Value.

$292.943

417.394

573,707

o547,000

0 Estimated.

MARYLAND.

ARUNDEL FORMATION.

The Arundel formation, which is so named because of its great 

development in Anne Arundel County, Md., carries a large number 

of lenticular clay deposits, but the clays are of variable character.

Some are refractory,83 but their occurrence appears to be erratic. 

In recent years a clay has been obtained from the Arundel formation

between Contee and Muirkirk, which resembles a crucible clay in its 

properties and has been used somewhat in mixtures for that purpose. 

Bleininger 84 describes the properties of this clay as follows:

In appearance this clay resembles very closely the Klingenberg clay. It is 

black and high in organic matter and exhibits the same characteristic stickiness. It resists slaking in water still more than the Klingenberg clay, though 

it has a higher pore-shrinkage water ratio. * * * The modulus [of rupture] is 518 [pounds per square inch]. * * * Its porosity at 1,090° [C.] is 

21.80 [per cent], * * * and its temperature of complete vitrification

* * * is about 1,250° C. The clay, however, reaches a go.od density at 

1,200°. Expansion begins to take place somewhat below 1,350°, and this change 

becomes accelerated markedly at 1,400°, followed by a stage of quiescence.

* * * The softening point is that of cone 31. It would seem that this clay 

should be valuable for the crucible industry, though less suitable for glass 

refractories.

Only a few small openings have been made in the clay, and its 

extent is uncertain. In 1918 it was being shipped to the steel works.

PATAPSCO FORMATION.

This formation, which underlies the Raritan in Maryland, is best 

developed in the valley of Patapsco River. It is a prominent member of the Cretaceous in that State, however, and extends from the 

Delaware border to Potomac River.

All the clays found in it are by no means refractory, but in Cecil 

County at Jeast there are a number of deposits which are quite 

plastic and whose fusion point lies at cone 27 (1,670° C.) or higher. 

They are all lenticular and may be of small extent but are worth 

examination by those searching for refractory bond clays.85

63 Ries, H., Report on the clays of Maryland: Maryland Geol. Survey, vol. 4, p. 431, 

1902.

84 Blelnlnger, A. V., and Loomis,. G. A., Properties of some American bond clays: Am. 

Ceramic Soc. Trans., vol. 19, p. 621, 1917.

"Rles, H., op. cit, p. 413.
202 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

UPPER CRETACEOUS CLAYS.

RARITAN FORMATION.

NEW JERSEY. 

OCCURRENCE AND DISTRIBUTION.

The high-grade clays of New Jersey occur almost exclusively in 

the Earitan formation. This formation has been classed as Lower 

Cretaceous by the New Jersey Geological Survey,86 but by the United 

States Geological Survey 87 and the Maryland Geological Survey 88 it 

is now considered to be the lowest formation of the Upper Cretaceous 

- series as found in the Atlantic Coastal Plain.

The value of the Raritan clays was emphasized in the report by 

Cook 89 in 1878, and since then the development of the area has been 

steady.

The Raritan in New Jersey forms a broad belt that extends from 

Raritan Bay across the State to Trenton and Bordentown, and a 

much narrower strip extends down Delaware River as far as Salem 

County, its greatest width being 8 miles. The Raritan beds are in 

most places covered by later sands and gravels, which may be so 

thick as not only to conceal them but to prevent mining.

The Raritan consists of a number of beds of clay, sand, and gravel. 

It is characterized by abrupt transitions in the character of the beds, 

which commonly occur either vertically or horizontally, so that a bed 

of clay may pass abruptly into a bed of sand or a bed of sand may 

pass into a bed of clay. These transitions naturally make the correlation of beds in separated sections rather difficult, and a subdivision 

of the formation in Middlesex County has been made possible only 

by the comparison of the numerous sections exposed in pits and cuts.

The beds of the formation dip gently to the southeast. The basal 

beds rest on Triassic shales in Middlesex County, but from Trenton 

south westward the underlying rock is pre-Cambrian gneiss and 

schist. The Raritan is overlain by the Upper Cretaceous clay and 

marl series.

New Jersey is one of the three leading States in the ceramic industry. It not only supports a number of ceramic factories of all sorts 

but is the seat of a thriving clay-mining industry.

M Ries, H., Kiimmel, H. B., and Knapp, G. N., The clays and clay industry of. New 

Jersey: New Jersey Geol. Survey Final Rept., vol. 6, p. 161, 1904. Also later New 

Jersey reports.

OT Veatch, A. C., Underground water resources of Long Island, N. Y.: U. S. Geol. Survey Prof. Paper 44, pp. 25-26, 1906. Also Stephenson, L. W., Cretaceous deposits of the 

eastern Gulf region: U. S. Geol. Survey Prof. Paper 81, p. 20, 1914, and other reports.

88 Clark, W. B., Geol. Soc. America Bull., vol. 20, p. 648, 1910; also Clark, W. B., 

Bibbins, A. B., and Berry, E. W., Maryland Geol. Survey, Lower Cretaceous, pp. 27, 29, 

57, 1911.

89 Cook, G. H., and Smock, J. C., Report on the clay deposits of Woodbridge, South 

Amboy, and other places in New Jersey, New Jersey Geol. Survey, 381 pp., 1878.
SEDIMENTARY CLAYS. 203

The State therefore attracted considerable attention during the 

World War, not only because it maintained industries that, were necessary to the prosecution of the war but because it shipped fire clay 

from deposits in Middlesex County to these industries in other States. 

New Jersey, however, could supply but small quantities of the types 

of raw materials that were imported in large quantities from Europe 

before the war.

USES OF THE CLAYS OF NEW JERSEY. 

By G. H. BROWN.

The unprecedented demand for fire clay and fire brick during the 

World War very shortly caused the price of these commodities to rise. 

The shortage of labor in Middlesex County caused by the activity 

of munition and other factories seriously handicapped the clay 

miners in filling orders for their materials. This shortage of labor 

became more acute as the war progressed, and during 1918 it was 

the direct cause of the cessation of work at several mines.

In selecting a site for the Raritan depot the Government unfortunately took a part of the property of the Raritan Ridge Clay Co. 

and other firms near Metuchen, which cut off the production of some 

of the best grades of clay in that district.

The unprecedented demand and the high prices paid for fire brick 

caused many companies, such as those commonly engaged in making 

terra cotta, to engage in the manufacture of refractory products and 

thus to increase the use of the fire clays of New Jersey.

The electrical-porcelain industry was operated at full capacity, 

but this industry has never depended largely on the clay of New 

Jersey, and the same statement applies to the floor and wall-tile and 

sanitary-ware industries. No clay from New Jersey was used for 

graphite crucibles at the beginning of the war, but a very good 

crucible clay mixture has been developed from the clays of Middlesex County and is now being used in the manufacture of graphite 

crucibles, mostly in plants outside the State.

The clays of New Jersey have proved of great value in the manufacture of the saggers and slabs that are used for containing and 

supporting abrasive wheels in the kilns during burning, but they 

have not been found adapted for use in the bond of such wheels.

A small quantity of ball clay from New Jersey is used in the manufacture, of sanitary ware, but there is no general use of clays from 

New Jersey for this purpose, as they are inferior in strength and 

color after burning to those obtainable from other sources.

Clays from New Jersey are not used either, so far as known, in 

the manufacture of glass refractories.

The most notable development, recently, because of its relation to 

foreign material has been the discovery and operation of a deposit of
204 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

clay which proved to be an excellent substitute for the German Klingenberg clay that was formerly imported and used in the manufacture 

of pencil leads. The deposit is a surface bed of Eecent age, and hence 

is not a part of the Earitan formation. It is near Metuchen and is 

owned by Mr. Wm. Dinwiddie. At the present time about 90 per 

cent of the pencil leads made in the United States are said to contain 

this clay.

MARYLAND.

The Earitan formation overlies the Patapsco in Maryland, and in 

places contains large deposits of clay. It occurs in Cecil and Kent 

counties and extends southwestward on the western shore of Chesapeake Bay along the southeastern border of Harford and Baltimore 

counties into Anne Arundel County, where it occupies a large area 

along Severn Eiver. The formation contains a number of deposits 

of clay, some of which are described by the writer in the report of 

the Maryland Geological Survey,90 but none of these clays have so 

far been used in glass refractories or graphite crucibles. Some of 

them are refractory, but nothing definite is known regarding their 

porosity on burning or their firing range.

Some deposits of white clay are found along Severn Eiver, but they 

are small.

TUSCALOOSA FORMATION.

The Tuscaloosa formation consists of sands, clays, and gravels 

which are irregularly bedded and have a total thickness of 1,000 

feet.91 The clays range from massive to thinly laminated in structure and are variable in color.

The Tuscaloosa is chiefly restricted to central and western Alabama 

and northeastern Mississippi. In both these States it carries deposits 

of white clay. The formation also occurs in Perry County, Tenn., 

but there it has no clays of economic value, and it is probably also 

represented as far north as Trigg County, Ky.92

ALABAMA.

In northwestern Alabama the white clays of the Tuscaloosa formation at Chalk Bluff, 4£ miles south of Hackleburg, Marion County, are 

well known but have never been mined to any extent. At this locality 

the clay is 20 feet thick. The upper 8 feet is somewhat more sandy 

than the lower 12 feet, but the bed can be traced for several miles, 

although its thickness is not uniform.

90 Ries, H., Report on the clays of Maryland: Maryland Geol. Survey, vol. 4, pt. 3, 1902.

91 Stephenson, L. W., Cretaceous deposits of the eastern Gulf region: U. S. Geol. Survey Prof. Paper 81, p. 20, 1914.

M Berry, E. W., U. S. Geol. Survey Prof. Paper 112, pp. 12, 13, 26-29, 1919; Stephenson, L. W., and Wade, Bruce, idem, map, 1919.
SEDIMENTARY CLAYS. 205

The deposit is less than 1 mile from a good macadam road, and 

water can be obtained within half a mile of the deposit.

The following tests of this clay were made in the laboratory of 

the Bureau of Mines, at Columbus, Ohio :

General physical tests of clay from Chalk Bluff, Marion County, Ala.

Workability- _____ ____ Fair; chips easily when dryWater of plasticity __________________per cent 34.05 

Air shrinkage by volume_______ __________do__ 15.95 

Air shrinkage, linear, calculated ______________do____ 5. 50

Modulus of rupture: i

Kaw clay ________ _pounds per square inch__ 53.00

Mixture of clay and sand in proportion of 1:1__do__ 23. 56

Fire tests of clay from Chalk Bluff, Marion Count1}/, Ala.

Temperature (°C.).

1,190...........................

1,250...........................

1.310...........................

1,370...........................

1,410...........................

Porosity 

(per cent).

32.10

36.10

30.22

28.30

90 4ft

Color.

.....do............................

.....do............................

Volume

shrinkage 

(per cent 

in terms of 

volume of 

dry clay).

18.40

23.40

29.93

33.70

39.10

Linear 

shrinkage 

(per cent).

7.00

8.50

11.00

13.00

15.00

Fusion point, cone 33. Steel hard at 1,250° C. Develops minute cracks in 

firing.

The clay burns sufficiently white to be used in the manufacture 

of pottery, but its transverse strength and bonding strength are very 

low. For pottery it would have to be mixed with a more plastic 

clay. The clay is very fine grained and could probably be used in 

the manufacture of paper, paint, or rubber. It is similar in many 

respects to the clay obtained at Cold Spring, Va. (See p. 101.)

Deposits similar in character to the Chalk Bluff clay are found 

near Pearces Mills in Marion County and Pegram in Colbert County. 

These deposits have never been developed.

MISSISSIPPI.

DISTRIBUTION AND CHARACTER.

The Tuscaloosa formation occupies a comparatively small area in 

the northeastern part of Mississippi, and it outcrops in the counties 

of Lowndes, Monroe, Itawamba, Prentiss, Alcorn, and Tishomingo.

Its clays are said by Logan 93 to be among the most refractory of 

those found in the State. Chemical analysis shows that most of 

them run rather high in silica and that they also commonly run 

under 1 per cent of iron oxide.

M Logan, W. N., The pottery clays of Mississippi: Mississippi Geol. Surrey Bull. 6, 

p. 102, 1914.
206 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

 The. lenses of white clay seem to be rather abundant, but no systematic attempt seems to have been made to determine the available 

quantity of material in them. Some of the best deposits are said to 

occur north and south of luka, in the northeastern corner of the State.

UNDEVELOPED PROPEBTIES IN TISHOMINGO COUNTY.

By E. N. LOWE.

The following undeveloped deposits have been examined by the 

Mississippi Geological Survey:

Tishomingo. There is clay on the land of James Starkey, 6 miles 

northeast of Tishomingo on the Birmingham branch of the Illinois 

Central Kailroad. No pits have been opened on the deposit, but the 

clay is exposed in washes 200 or 300 yards from the public road. At the 

point where the examination was made and the sample was taken the 

clay is highly plastic, free of all grit and sand, and light bluish-gray, 

though near the exposed surface slight yellowish discolorations due 

to iron oxide appear. This stain was especially noticeable on joint 

surfaces. The clay has no other observable impurities. Where it is 

not exposed to the weather it is firm and shows conchoidal fracture.

The exposed thickness of this clay is 6 feet, but its actual thickness is perhaps much greater. It is exposed in most slopes and is 

probably continuous with a deposit at a negro house half a mile to 

the south and possibly also with that which was struck in a well at 

the old Clingscale residence 1 mile south of Starkey's.

The clay fuses at cone 29 (1,650° C.) and has a transverse strength 

of only 76.7 pounds to the square inch.

Hilgard 94 mentions a fine white clay that was struck in a well on 

the Clingscale place at a depth of 30 feet. The well was dug 30 feet 

deeper, but it stopped in the clay.

luka. On the land of John Castlebury, 4 miles southeast of luka 

and three-fourths of a mile from Gravel siding, on the Southern 

Railway, there is a large deposit of white clay from which small 

shipments have been made. A pit 75 feet long has been opened, and 

the clay has been prospected also by small pits and borings along 

the hillside for a distance of 250 feet. It undoubtedly extends farther. 

Outcrops of a similar clay occur 1 mile east of this pit. Further 

prospecting may prove the clay to be continuous between the two 

points.

The face of the Castlebury pit shows 15 feet of massive white joint 

clay to the bottom of the pit. The clay extends for an unknown 

depth below the bottom of pit. Dark-gray laminated sandy clay 

4 to 6 feet thick lies unconformably upon the massive white clay. 

Above this dark-gray clay lies 5 to 7 feet of gravelly soil.

M Hilgard, E. W., Geology and agriculture of Mississippi, p. 35, 1860.
SEDIMENTARY CLAYS. 207

The clay in this pit is not high in plasticity, owing to the appreciable content of very fine white silica that is intimately mixed with it. 

This silica seems to be identical with that contained in the deposits 

of tripolite, which are interbedded with Carboniferous chert beds 

a few miles farther north and east. No other visible impurities exist.

The following tests of this clay, made by C. W. Parmelee, of the 

University of Illinois, have been furnished by the Mississippi Geological Survey:

General physical tests of clay from Castlebury pit, 4 miles southeast of luka, 

Tishomingo County, Miss.

Kind of material______White plastic clay of medium hardness. 

Working properties______________ _ Good. 

Conduct when flowing through die_ __ Good. 

Water of plasticity_________-__ ___-percent 28.8 

Plasticity_____ __ - Low.

Shrinkage water, in terms of volume of true clay_per cent_ 7. 25 

Pore water, in terms of volume of true clay _ do 20.54 

Modulus of rupture (average) :

Raw clay____________pounds per square inch SO 

Mixture of clay and sand, in proportion of 1:1__do__ 33.1 

Fineness test:

Residue, 20-mesh sieve_________ ___per cent 0.29 

Residue, 40-mesh sieve_ __ __ _ do____ . 19

Residue, 60-mesh sieve..______________do____ .20

Residue, 120-mesh sieve____ __ _______do __ .93

Residue, 200-mesh sieve __ _ do . 52 

Linear drying shrinkage_________ ____ do____ 6.11

Drying conduct___ Fair; small cracks appear on surface during 

drying.

Fire tests of clay from Castlebury pit, 4 miles southeast of luka, Tishomingo

County, Miss.

Cone.

05

03

2

5 ~ 9

12

14

15

Temperature (°C.).

1.050

1,090

1,170

1,230

1,310

1,370

1.410

1,430

Porosity 

(per cent).

38.7

39.2

39.0

37.8

36.2

30.5

32.6

30.8

Color.

.....do.......................

.....do.......................

.....do.......................

.....do.......................

.....do.......................

Hardness.

.....do......................

.....do......................

.....do......................

.....do......................

.....do......................

Linear 

shrinkage 

(per cent).

1.0

1.32

1.51

1.71

4.20

4.11

3.16

Fusion test: Deformed at cone 31 (1,750° C.).

The following general conclusions have been reached regarding 

this clay: Plasticity, low; drying shrinkage, normal; strength of 

unburned clay, low; bonding strength, low; fire shrinkage, normal; 

porosity, high at all temperatures; color, good except for small 

reddish specks.

The clay is classed as an open-burning refractory clay, having 

low plasticity and strength. Its color might possibly be improved
208 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

by washing. Its high fusion point makes it available for the manufacture of refractory wares, such as fire brick and saggers.

Another outcrop of clay occurs on the luka and Alsboro road, 4 

miles south of luka, at Pennywinkle Hill, on the land of George 

Martin, in sec. 5, T. 4 S., R. 11 E.

The thickness of the visible deposit is 18 feet. Above this clay 

lies 5 feet of thickly bedded, dark-gray sandy clay that contains thin 

laminae of lignite, which locally include small masses of amber. 

Above this laminated clay there is 10 feet of yellowish-red sand.

A well dug 200 yards south of this outcrop exposed clay that was 

apparently the same in quality, but the thickness exposed in the well 

is unknown. All wells in this vicinity enter similar clay.

This material is a bluish-gray joint clay, which becomes lighter in 

color toward the base of the exposure.

The following tests of this clay, made by C. W. Parmelee, of the 

University of Illinois, have been furnished by the Mississippi Geological Survey:

General physical tests of clay from Pennywinkle Hill, near luka, Miss.

Kind of material _Nearly white, plastic clay of medium hardness.

Working properties________________________ Good.

Conduct when flowing through die_______________ Fair.

Water of plasticity. _______________per cent 30.9

Plasticity______________________________ Good.

Shrinkage water, in terms of volume of true clay_per cent_ 8.3

Pore water, in terms of volume of true clay______do__ 22. 6

Modulus of rupture (average):

Raw clay pounds per square inch__ 164 

Mixture of clay and sand, in proportion of 1:1_do__ 52

Fineness test:

Residue, 20-mesh sieve___________per cent 0.26 

Residue, 40-mesh sieve_______________do__ .15 

Residue, 60-m'esh sieve._______________do__ .15 

Residue, 80-mesh sieve _____________do__ .03 

Residue, 120-mesh sieve_______________do__ .32 

Residue, 200-mesh sieve_____________do__ .33

Linear drying shrinkage ___________'.___do__ 5. 54

Drying conduct ______ Surface cracks form during drying.

Fire tests of clay from Pennywinkle Hill, near luka, Miss. 

(5SST). Color. Hardness.

05 1,050 40.7 Yellow-white................ Nearly steel hard........... 2.26

03 1.090 38.8 .....do....................... .....do...................... 2.50

2 1,170 37.0 .....do...............1....... .....do...................... 4.16

5 1,230 35.4 Cream-white......:.......... Steelhard................... 3.95

9 1,310 25.6 .....do....................... .....do....................... 7.57

12 1,370 23.7 .....do....................... .....do...................... 7.58

14 1,410 22.3 .....do....................... .....do...................... 7.75

15 1,430 17.6 .....do....................... .....do.

Fusion test. Deformed at cone 30 (1,730° C.).
SEDIMENTARY CLAYS. 209

The following general conclusions have been reached regarding this 

clay: Plasticity, good; drying shrinkage, normal; modulus of rupture, low, possibly due to checking in drying; bonding strength, low; 

porosity after firing, high; fire shrinkage, normal; color after firing, 

yellowish white, which is slightly intensified at the higher temperatures, with appearance of numerous reddish to brownish specks at 

temperatures above cone 9 (1,310° C.).

If the clay can be purified by some treatment to remove the specks, 

it will be of use for pottery, otherwise its high fusion point makes it 

of value for refractory wares.

Golden On the land of Dock Clement, in sec. 16, T. 7 S., R. 10 

E., 2 miles southwest of Golden, on the Birmingham branch of the 

Illinois Central Railroad, there,is an outcrop of good clay. The 

outcrop shows 3 or 4 feet of clay in the banks and bottom of a small 

creek.

The clay is highly plastic and free from sand or other visible impurities. It is bluish gray while wet, but dry specimens seen in 

luka were creamy white. Neither the depth nor the lateral extent 

of this deposit could be discovered at the time of examination, but as 

it occurs continuously along the creek bed for 50 to 75 yards it is 

probably present in commercial quantities. The Cretaceous clays 

of this county occur usually in extensive deposits.

No pit has been opened on this clay. The overburden is a thick 

mass of cherty gravel 25 to 40 feet thick, which if tapped by a spur 

.track from the railroad 2 miles away, would be a commercial product 

for road material.

The clay is not fused at cone 28 (1,690°C.) and has a transverse 

strength of 170.6 pounds to the square inch.

Eastport At the head of Eastport Hollow, in the bed of a small 

creek running north, at a point opposite Eastport Church, in sec. 27, 

T. 2 S., R. 11 E., about 3 miles from Tennessee River, a bed of clay 

outcrops on the property of C. A. Hill.

The deposit lies on the public road between Eastport and luka, 3 

miles from the Eastport landing on Tennessee River, and 5 miles 

from the Southern Railway at luka.

The clay is creamy white, with yellowish stains toward the northern end of the outcrop, but toward the southern end this changes 

to uniform light gray. The only impurity noted was a small proportion of iron oxide discoloring the clay toward the northern end 

of the outcrop, as before stated. o

This clay can be seen to outcrop along the creek bottom for 250 

yards, but probably extends much farther under cover. Its depth has 

not been determined but is not less than 6 feet, perhaps much more. 

It extends across the creek bottom or flat, 100 yards wide, and passes 

beneath the hills on each side to unknown distance. In the creek
210 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

bottom the clay is covered by alluvium 5 to 9 feet thick, and under 

the hills the overburden consists of gravel deposits 50 to 75 feet thick, 

excellent for -road construction. Both the clay and the gravel are 

of Cretaceous age.

C. A. Hill has 1 in the past shipped considerable quantities of clay 

to the Ceramics Department of Sophie Newcomb College, Ne\v 

Orleans.

The following tests of this clay, made by C. W. Parmelee, of the 

University of Illinois, have been furnished by the Mississippi Geological Survey:

General physical tests of clay from Eastport, Miss.

 Kind of material__Light-brown, plastic clay of medium hardness.

Working properties_ _ ____._________ Good.

Conduct when flowing through die_______________ Fair.

Water of plasticity- ______ ___ __per cent 81.4

Plasticity_____________.________________ Good.

Shrinkage water, in terms of volume of true clay__per cent 36.15

Pore water, in terms of volume of true clay _____do__ 45.15

Modulus of rupture (average) :

Raw clay_____ ______pounds per square inch 474 

Mixture of clay and sand, in proportion of 1:1_do__ 130

Fineness test:

Residue, 20-niesh sieve__________ _per cent_ 

Residue, 40-mesh sieve________:_______do__ 

Residue, 60-mesh sieve__________-_ _do____

Residue, 80-mesh sieve____________ _do__

Residue, 120-mesh sieve ______________do__ 

Residue, 200-mesh sieve_______________do__

Linear drying shrinkage_________________do____

0.25 

.17 

.25 

.12 

.75 

.21 

10.81 

Drying conduct__________:_.______________ Good.

Fire tests of clay from Eastport, Miss.

Cone.

05

03

2

5

9

12

14

Temperature (°C.).

1.050

1,090

1.170

1.230

1,310

1,370

1,410

Porosity 

(per cent).

72.6

50.1

47.0

49.8

40.1

26.0

.127

Color.

Light-buff...................

.....do.......................

.....do........................

.....do.......................

Hardness.

.....do......................

.....do......................

.....do......................

.....do......................

Linear 

shrinkage 

(percent).

3.26

4.17

5.26

5.56

9.30

13.9

7.76

Fusion test Deforms at cone 28 (1,690° C.).

The following general conclusions have been reached regarding 

this clay: Plasticity, good; drying shrinkage, normal; strength of 

unburned clay, good; bonding power, fair; ,fire shrinkage, rather 

high with increasing temperature; porosity, high up to cone 12; 

color after firing, rather dark.

The clay is classed as a low-grade refractory clay, which because 

of its dark color after firing can not be used for making the better
SEDIMENTARY CLAYS. 211

grades of pottery. It can be used in certain classes of wares, such 

as saggers and second-grade fire brick, which are not expected to 

meet very severe conditions when in use.

MIDDENDORF ARKOSE MEMBER OF BLACK CREEK FORMATION IN SOUTH

CAROLINA.

By W. S. BAYLEY.

The Black Creek formation of the Upper Cretaceous has been 

recognized in North Carolina and South Carolina. At the base of 

the formation in South Carolina lies the Middendorf arkose member, 

which contains extensive deposits of white clay similar to and closely 

associated with the Lower Cretaceous white clays that are found in

the same region.

WARRENVILLE, AIKEN COUNTY.

Property of Parker Kaoliri Co. The Parker Kaolin Co.'s mine 

is alongside the Southern Kailway, 4 miles west of Aiken. Its post 

office is 'Warrenville. The property consists of 41 acres, over which 

borings at irregular intervals indicate the presence of clay everywhere except in narrow valleys,or gullies, where it has been removed by erosion.

The place has been worked by several people and contains many 

large openings, which are on a low plateau intersected by valleys, 

from which the clay has been cut out completely. However, it outcrops on the slopes of the valleys in such a way as to indicate the 

essential horizontality of the bed. The overburden consists mainly 

of yellow sand, which ranges in thickness from 1 to 20 feet. The 

clay bed measures from 6 to 7 feet in thickness.

A section on the wall of a newly opened pit shows the following 

sequence:

Section in new pit of Parker Kaolin Co., Warrenville, 8. C.

^

Feet. 

Coarse current-bedded yellow sand, containing still coarser

sand ait bottom and a few thin layers of clay_________ 18 

Pebbly limonite in which nodules of clay are common_____ £-£ 

Stained yellow clay (ruggage)___________________ 2-3 

White clay______________________________ 6-7 

White sandy clay___________________________ 6 

White gravelly sand; thickness unknown.

The clay that is worked is white, compact, and apparently free from 

grit. It is not quite so dense as that mined at the Interstate pit. 

The sizes of its components are the same as those of the Interstate 

clay, but the coarser grains are more numerous. Flakes of mica 

measuring 0.02 millimeter in diameter are numerous and there are
212 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES.

also many black particles that may be rutile. The output consists 

entirely of crude clay, which is dug by hand and dried before shipment at Parker siding on the Southern Kailway.

The following tests of a sample of white clay (Bureau of Mines, 

No. 1.22) from the pit of the Parker Kaolin Co. have been supplied 

by the laboratory of the Bureau of Mines at Columbus, Ohio:

General physical tests of sample of clay from the pit of Parker Kaolin Co., near

Warrenville, S. C.

Workability Fairly plastic; makes'good bars; cracks slightly. 

Water of plasticity, in terms of dry clay______per cent 43. 76 

Air shrinkage by volume_________________do__ 17. 90 

Air shrinkage, linear, calculated____________do__ 6.20

Fire tests of sample of clay from pit of Parker Kaolin Co., near Warrenville,

S. C.

Temperature (°C.).

1,190............................

1,250............................

1,310............................

1,370............................

1,410............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

37.64 

37.30

32.83

22.80

6.20

Color.

White.................................

.....do.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(percent 

in terms 

of volume 

of dry 

clay).

24.90 

25.80 

32.58 

40.24 

48.50

Linear 

shrinkage, calculated (per 

cent).

9.1 

9.5 

12.3 

15.8 

17.3

Cone of fusion, 34.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelam body containing clay from pit of Parker 

Kaolin Co., near Warrenville, 8. C.

Workability-_____ Very plastic; makes good bars; jiggers well;

dries slowly, but safely.

Water of plasticity, in terms of dry clay_____per cent 32.79 

Volume shrinkage _____________ ___do__ 18.81 

Air shrinkage, linear, calculated___________do__ 6.70 

Modulus of rupture________pounds per square inch 166. 20

Fire tests of porcelain lody containing clay from .pit of Parker Kaolin Co.,

near Warrenville\, S. C.

Temperature (°C.).

1,190...................

1,250................... 

1,310................... 

1,370...................

1,410...................

Porosity 

(percent 

in terms 

of volume 

of burned 

clay).

25.60

24.00 

18.20 

.72

.06

Color.

Wlii to

.....do................................. 

.....do................................. 

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

20.10

21.00 

24.36 

35.04

36.34

Linear shrinkage, calculated (per 

cent).

7.2

7.6 

8.9 

13.4

14.0

Modulus 

of rupture 

(pounds 

per 

square 

inch).

3.432

3,978 

4,265 

10,268

9,090
SEDIMENTARY-CLAYS. 213

The Parker clay has been used as filler for box and cardboard and 

for newsprint paper by manufacturers who have never found it 

necessary to import clay to meet their needs. It is employed as a 

substitute for imported clays that were formerly used as filler for 

ticking and is mixed with imported clay for filling window-shade 

cloth. It is also used for coating and top printing wall paper. In 

top printing it is mixed with pulp colors and the colored clay is 

printed on the coated surface. For this purpose the Parker clay 

seems in general to have the proper physical characters, but some of 

it is marred by yellow streaks. However, it is being used to a considerable extent in place of English clay.

In addition to its clay the mine has a source of income in the 

overburden. About 500 tons of sand, grit, and impure clay intermingled have been sold to the city of Aiken for road metal.

EAYFLIN, LEXINGTON OOTTNTY.

'Property of Edisto Kaolin Co. The pit of the Edisto Kaolin Co. 

is 2% miles west of Rayflin, a station between Seivern and Steedman 

on the branch of the Southern Eailway that connects Perry and 

Batesburg. The post office of the plant is Samaria, and the office 

of the company is at Bridgeport, Conn.

The property consists of 269f acres, of which 135 acres are shown 

by borings -to be underlain by a clay bed from 8 to 16 feet thick. 

A part of the remainder of the property is a valley from which the 

clay has been entirely cut out, but the greater part of it is upland, 

which is underlain by the same bed of clay as that under the bored 

area. The overburden, which is from 6 to 18 feet thick, is composed of current-bedded sand and interlayered seams of limonite. 

If the clay is all of commercial quality the available quantity under 

the bored area is more; than 3,000,000 tons. A well on the property 

160 feet deep shows that sand underlies the clay to this depth.

The clay is very light cream-colored, almost gritless, and very 

finely granular. It contains a very little sand and here and there 

a minute yellow spot. When crumbled and shaken up with water it 

forms a darker, yellowish suspension that settles rapidly.

Under the microscope the kaolinite is seen to occur in thin scales 

and grains from 0.002 to 0.01 millimeter in diameter and in small 

wormlike groupings. Besides the kaolinite a very few tiny grains 

of quartz, biotite, altered muscovite, zircon, and rutile are present. 

The quartz occurs in sharp-edged grains a little larger than the 

grains of kaolinite, but these grains are usually grouped together in 

little clumps. Few of the little yellow spots are more than 1 millimeter in diameter. Under the microscope they appear as little 

masses of quartz, mica, and various undeterminable minerals showing stains of iron oxides in the cracks between them and surround77412 22 18
214 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

ing their peripheries. They thus seem to be grains of some ironbearing mineral that has entirely broken down under the decomposing 

agencies.

Formerly the clay was washed, but the process was npt successful 

commercially, possibly because the washer and settling tanks are at 

a higher elevation than the pit, so that all the clay and water used 

in the entire process of preparation had to be raised. Until recently 

only crushed clay was marketed, but there have now been installed 

two pulverizers, which will crush 10 tons to 150 mesh in 10 hours. 

The average output of the plant before the pulverizers were operating was 260 tons monthly. This low production was due to lack of 

labor. With plenty of labor the output will be doubled.

Reports from potters indicate that the clay is very satisfactory in 

the manufacture of white ware. It is said to burn pure white and to 

be unusually plastic.

The following tests of a sample of white clay (Bureau of Mines 

No. 1.53) from the pit of the Edisto Kaolin Co. have been supplied 

by the laboratory of the Bureau of Mines at Columbus, Ohio:

General physical tests of sample of clay from pit of Edisto Kaolin Co., Rayflin,

8. C.

Workability_______________Fairly plastic; makes good bars.

Water of plasticity, in terms of dry clay______per cent_ 43.80 

Air shrinkage by volume_________________do__ 33.02 

Air shrinkage, linear, calculated____________do__ 12. 50

Fire tests of sample of clay from pit of Edisto Kaolin Co., Rayflin, S. C.

Temperature (°C.).

1,190.............................

1,250.............................

1,310.............................

1,370.............................

1,410.............................

Porosity 

(percent 

in terms 

of volume 

of burned 

clay).

32.70 

30.80

23.02

16.38

2.00

Color.

White.................................

.....do.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(percent 

in terras 

of volume 

of dry 

clay).

28.40 

31.10 

38.00 

43.31 

46.30

Linear 

shrinkage, calculated (per 

cent).

10.5 

11.7 

14.7 

17.3 

18.7

Cone of fusion, 34.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain body containing clay from pit of Edisto 

Kaolin Co., Rayflin, S. C.

Water of plasticity, in terms of dry clay_____per cent 28. 74 

Volume shrinkage____-___-___________ do____ 18.03

Air shrinkage, linear, calculated____________do__ 6. 50 

Modulus of rupture________pounds per square inch_ 171.00
SEDIMENTARY CLAYS. 215

Fire tests of porcelain body containing clay from pit of Edisto Kaolin Co.,

Rayflin, S. C.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(percent 

m terms 

of volume 

of burned 

clay).

18. 40 

18.33 

13.24

.58 

.30

Color.

.....do.................................

.....do.................................

Volume 

shrinkage 

(percent 

in terms 

of volume 

of dry 

clay).

23.31 

23.31 

27.32 

32.04 

31.32

Linear 

shrinkage, calculated (per 

cent).

8.5 

8.5 

10.1 

12.1 

11.8

Modulus 

of rupture 

(pounds 

per 

square 

fnch).

2,203 

2,900 

3,546 

4,164 

2,004

The overburden is removed by scraper, and the clay loosened by 

dynamite before digging. It is dried and hauled by mule teams 

2£ miles to Rayflin, where it is loaded on a siding of the Southern 

Railway. When the road is rebuilt the clay will be hauled to the 

railway by truck.

Perhaps the principal use to which this clay has been put is in 

the manufacture of wall paper. It is employed both for coating 

and top printing and also as filler, sometimes alone and sometimes 

in mixtures with other clays. It is also used as filler for print paper 

and for coarse textiles, such as wall fabrics, and some of it is blended 

with washed clay from other States for kalsomine and other coldwater paints. It is mixed with other materials to reduce the color 

of strong pigments in oil paints and takes the place to some extent 

of imported china clay. It has also been used to a small extent' in 

semiporcelain and china mixtures, replacing English clay in part. 

Now that a pulverized product is being furnished, the use of this 

clay will be greatly extended.

HORKELL HILL, HIGHLAND COUNTY.

Property of Interstate Clay Co. The Interstate Clay Co.'s pit is 

near Horrell Hill, Richland County, 4 miles northwest of Congaree, 

on the Atlantic Coast Line, with which it is connected by a standardgage spur. It is ! £ miles northeast of James Crossing, which is its 

nearest railroad station. Its administrative office is at Sumter, S. C. 

The plant has been in operation since 1916.

The land controlled by the company includes 110 acres. Of this 

area 20 acres has been tested by borings at intervals of 50 feet, and 

from the data thus obtained an estimate of 700,000 tons in reserve 

has been reached. This estimate seems a little excessive. A more 

reasonable estimate, if the average workable thickness of the bed is 

taken as 9 feet, gives 500,000 tons. The figures have little significance, however, for an enlargement of the area for which the estimate is given would correspondingly increase the size of the reserve.
216 HIGH-GKADE CLAYS OF THE EASTERN UNITED STATES.

Messrs. Maynard and Simmons, of Atlanta, Ga., estimate the entire 

reserve at 1,250,000 tons. In the last analysis the size of the available reserve will probably depend upon the distribution of the overburden, for the cost of the production of the clay is increased by the 

cost of the removal of a greater thickness of the overburden.

The clay is shipped in four grades, two of which! 'are crude and 

two washed. Both the crude and the washed clays are divided into 

No. 1, white, and No. 2, white and pink mixed. The clay of all four 

grades is very dense and porcelain-like and contains almost no grit. 

The white clay is very light cream-colored when dug, but almost 

pure white when dry. When crumbled and shaken with water it 

forms a smooth creamy suspension. Its components in general measure from 0.003 to 0.02 millimeter in diameter, though a few grains 

of quartz and shreds of mica are a little larger. No rutile was seen 

under the microscope, though some grains are no doubt present. 

All the crude clay is crushed to the size of walnuts. None was pulverized at the time of the writer's visit, but the company planned to 

install pulverizing machinery in the near future.

At the pit now being worked there is an overburden of 6 to 30 

feet of yellow clay and sand. Under this overburden there is a white 

and pink streaked clay, with little layers of sandj pink clay at the 

top. Below^ this clay lies the bed of white clay, from 3 to 13 feet 

thick. The top layers are sandy. The material of these layers is 

saved for washing, as is also the best of the white and pink clay 

above it. Clay that isi strongly streaked will not wash white and 

therefore isl rejected. This material and the sandy pink clay above 

it, known as ruggage, is marketable, but its price is not regarded 

as profitable and, consequently, it is left in the pit.

The variation in the thickness of the overburden is due almost 

exclusively to the irregularities of the topography. As the clay bed 

is nearly horizontal the overburden thins where the surface falls 

and thickens where it rises. The only structural feature noticed in 

the beds above the commercial clay is the current bedding in the 

sandy pink layers. This bedding suggests that this particular layer 

was deposited in shallow water. '.

The overburden is removed by steam shovels and a drag machine. 

The clay is hauled to the washing plant where it is prepared for 

market. .

The plant is provided with a Chambers disintegrator and the usual 

sand troughs, settling vats, and presses. All the washed clay is 

passed through a rotating trough of 120 mesh. The plant was built 

for a daily capacity of 25 tons of crashed clay and 25 tons of washed 

clay, but this output is not reached because of lack of labor. The 

present monthly production is about 500 tons of crushed clay and
SEDIMENTARY CLAYS. 217

375 tons of the washed grade. Improvements and enlargements, now 

being made, will enable the output of washed clay to be increased 

to 50 tons daily and that of the crude clay to be nearly doubled. The 

labor problem is being partly solved by the1 building of comfortable 

dwellings for tenants.

The following tests of white clays from the pit of the Interstate 

Clay Co. have been supplied by the laboratory of the Bureau of 

Mines, at Columbus, Ohio :

General physical tests of sample of clay from pit af Interstate Clay Co., Horrell 

Hill, 8. C. (Bureau of Mines No. 1.45).

Workability .i__ Fairly plastic; makes good bars. 

Water of plasticity, in terms of dry clay______per cent 33.50 

Air shrinkage, by volume________________do__ 10.46 

Air shrinkage, linear, calculated__-_________do__ 3.6

Fire tests of sample of clay from pit of Interstate Clay Co., Horrell Hill, 8. C.

(Bureau of Mines No. 145).

Temperature (°C.).

1,190.............................

1.250.............1...............

1,310.............................

1.370.............................

1,410.............................

Porosity 

(per cent 

in terms 

of volume 

ol burned 

clay).

32.86 

33.20

30.87

17.41

7.60

Color.

White ..........................-...

.....do.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(percent 

m terms 

of volume 

of dry 

clay).

28.38 

29.30 

31.26 

41.80 

46.7

Linear 

shrinkage, calculated (per 

cent).

10.5 

10.9 

11.8 

16.5 

18.9

Cone of fusion, 34.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain body containing clay of sample. No. 145.

Water of plasticity, in terms of dry clay_______per cent 30.96

Volume shrinkage __ _______________do__ 18. 69 

Air shrinkage, linear, calculated_ _____do__ 6.7 

Modulus of rupture________pounds per square inch__ 141.3

Fire tests of porcelain body containing clay of sample No. 145.

Temperature (°C.).

1 190 ]'*><&

1,310...................

1,370...................

1,410...................

Porosity 

(percent 

in terms 

of volume 

of burned 

clay).

23.60 

24.53 

21.08

2.76 

.11

Color.

White

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(percent 

in terms 

of volume 

of dry 

clay).

19.70 

22.00 

23.57 

33.08 

34.24

Linear shrinkage, calculated (per 

cent).

7.1 

7.9 

8.6 

12.fi 

13.1

Modulus 

of rupture 

(pounds 

per 

square 

inch)..

2,621 

2,917 

3,594 

6,466 

6,624
218 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

General physical tests of sample of day from pit of Interstate Clay Co., 

Horrell Hill, S. C. (Bureau of Mines No. 1.7).

Workability______Very plastic; makes good bars; no cracking. 

Water of plasticity, in te.rms of dry clay____per cent 35. 09 

Air shrinkage by volume_______^_________do__ 14. 02 

Air shrinkage, linear, calculated____________do__ 4.9

Fire tests of sample of clay from pit of Interstate Clay Co., Horrell Hill, S. C. 

(Bureau of Mines No. JL7).

Temperature (°C.).

1,190.............................

1,250.............................

1,310..............................

1,370..............................

1,410.............................

Porbsity 

(percent 

in terms 

of volume 

of burned 

clay).

37.00 

32.60 

29.17

11.90 

2.00

Color.

White.................................

.....do.................................

Volume 

shrinkage 

(percent 

in terms 

of volume 

of dry 

clay).

24.60 

29.20 

31.75 

45.10 

48.20

Linear shrinkage, calculated (per 

cent).

9.0 

10.9 

12.0 

18.1 

19.7

Cone of fusion, 34.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain body containing clay of sample No. 1.7.

Water of plasticity, in terms of dry clay_____per cent_ 28. 49 

Volume shrinkage ____________________do__ 15. 35 

Air shrinkage, linear, calculated____________do__ 5. 4 

Modulus of rupture _______pounds per square inch 222. 8

Fire tests of porcelain body containing clay of sample No. .J.7.

Temperature (°C.).

1,190...................

1,250................... 

1,310...................

1,370...................

1,410...................

Porosity 

(percent 

in terms 

of volume 

of burned 

clay).

22.7 

24.18 

19.34

1.31 

.30

Color.

White.................................

.....do................................. 

.....do.................................

Volume shrinkage 

(percent 

in terms

of volume 

of dry 

Clay).

20.0 

20.48 

24.02 

33.23 

33.60 '

Linear shrinkagejCalculated(per 

cent).

7.2 

7.4 

8.8 

12.6 

12.8

Modulus 

of rupture 

(pounds 

per 

square 

inch).

4,073 

5.240 

4,241 

8,505 

8,492

The washed clay from this mine has been used for chemical and 

hard porcelain, but only in small quantities in a mixture which is 

composed mainly of English clay. For semiporcelain it is employed in larger quantities in the mixture. It is also used in making vitreous floor tile and will be used in larger quantity for this 

purpose when shipments are more regular. It will then replace an 

equal quantity of English china clay. It is mixed with other 'domestic clays for a filler for high-grade print papers. The crushed 

crude clay is employed for filling high-grade book paper, but it 

would serve the purposes of some manufacturers better if it were
SEDIMENTARY CLAYS. 219

finely pulverized, so that it might be better retained within the meshes 

of the paper stock. The No. 2 clay is used as a filler in oilcloth and 

linoleum and for other similar purposes.

Property of Columbia Mineral Products Go. About 300 yards 

from the pit of the Interstate Co. is the abandoned pit of the Keenan 

mine of the Columbia Mineral Products Co. The pit is small and 

there is now no means of determining the extent of the deposit, 

which is apparently the same as that worked at the Interstate pit. 

The overburden is about 20 to 25 feet thick and is the same in character as that at the neighboring Interstate pit. The clay also is 

apparently of the same type, but evidently more of the pink clay was 

taken out and saved. When examined carefully the pink clay is 

found to differ from the white clay only in being stained. Some 

masses are stained throughout, others are stained only superficially, 

and in others the stain extends irregularly inward, leaving portions

of the mass unstained. When the clay is crushed and treated with 

water its color changes to the characteristic ocher shade, and when 

boiled with hydrochloric acid it becomes white and the solution gives 

the usual reactions for iron. The stain is therefore probably produced by ocher. Possibly the red clay might be employed in the 

manufacture of a cheap red paint.

Near the pit and connected with it by an incline is the drying and 

storage shed, which is provided with a crusher. The crushed clay 

was bagged and probably hauled to James Crossing, on the Atlantic 

Coast Line.

The following tests of a sample of the best white clay (Bureau of 

Mines No. 169) from the pit of the Columbia Mineral Products Co. 

of Columbia, S. C., have been supplied by the laboratory of the 

Bureau of Mines, at Columbus, Ohio.

General physical tests of a sample of clay from the pit of the Columbia Mineral 

Products Co., of Columbia, S. C.

Workability____ _____ Fairly plastic; makes good bars. 

Water of-plasticity in terms of dry clay ____percent_ 35. 7 

Air shrinkage by volume_____ _____ ______do__ 11. 78 

Air shinkage, linear, calculated __ __ ___do__ 4.1

Fire tests of a sample of clay from the pit of the Cotiimbia* Mineral Products

Co., of Columbia, 8. C. .

Temperature (°C.).

1 ion

1 95fl

1,310.............................

1,370.............................

1,410.............................

Porosity 

(p.erceu't 

in terms 

of volume 

of burned 

clay).

37.20 

33.10

32.10

23.00

3.90

Color.

Whifp

.....do.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

22.4 

28.2 

29.88 

39.30 

46.00

Linear shrinkage, calculated (per 

cent).

8.1 

10.4 

11.2 

15.5 

18.6

Cone of fusion, 33.
220 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

A sample of this clay was used in a porcelain body and gave the 

results noted below:

General physical tests of porcelain body containing clay from the pit of the 

Columbia Mineral Products Co., of Columbia, $. C.

Workability_______-__________Dries well; no cracks. 

Water of plasticity in terms of dry clay ___per cent 29.10 

Volume shrinkage ____________________do__ 29.24 

Air shrinkage, linear, calculated ________ _do__ 10. 9 

Modulus of rupture________pounds per square inch_ 139.9

Fire tests of porcelain body containing clay from the pit of the Columbia 

Mineral Products Co., of Columbia, 8. C.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(percent 

m terms 

of volume 

of burned 

clay).

24.10 

22.90 

20.92

2.43 

.30

Color.

White.................................

.....do.................................

.....do.................................

.....do.................................

Volume 

shrinkage 

(per cent 

in terms 

of volume 

of dry 

clay).

. 19.2 

20.5 

23.35 

32.68 

33.10

Linear shrinkage, calculated (per 

cent).

6.9 

7.4 

8.5 

12.4 

12.5

Modulus 

of rupture 

(pounds 

per 

square 

inch).

3.137 

3,265 

4,181 

6,412 

6,401

AIKEN, AIKEN COUNTY.

Property of Henderson Bros. The Henderson Bros, prospect is 

about 3 miles a little west of north of Aiken, on the west side of the 

road between Aiken and Edgefield. In all there are 607 acres in the 

property, but only 40 acres has been tested. The area tested is underlain by a clay bed from 9 to 13 feet in thickness. If the average 

thickness is assumed to be 12 feet the quantity of clay in the 40 acres 

is approximately 1,000,000 tons, but the quantity of white clay can 

not be estimated. The overburden, exclusive of the yellow and pink

clay above the white clay, is from 4 to 13 feet thick. If the yellow 

and pink clays are considered valueless the thickness of the overburden is increased by 10 feet, for there is in most places a layer of 

yellow clay 7 feet thick and a thinner layer of pink clay above the 

commercial white clay. Mr. Henderson declares that there is a market for both shades of. colored clay, and he considers them to be 

valuable. Possibly they could be used in colored paints and kalsomine, but so far as is known none have been so used.

The property was worked about 6 years ago by the Pope Clay 

Products Co., and later for a short time by Mr. J. R. Parker, but 

very little of the clay was sold. The several small pits on the property are so overgrown that very little can be learned from them. In 

one pit white clay is directly overlain by sand. In another pit immediately under the sand is a 7-foot bed of yellow clay and beneath
SEDIMENTAEY CLAYS. 221

this about 1 foot of pink clay which grades down into the white clay. 

The pink clay apparently is stained white clay, whereas the yellow 

clay seems to be a distinct deposit. Where the pink clay is thickest 

the white clay is thinnest and where the white clay is thickest the 

pink clay is thinnest.

In the old dry shed on the property small quantities of all three 

varieties of the clay are stored on the racks. The white clay has a 

very pale pinkish tinge. It is smooth, dense, and extremely brittle and hard. It slakes slowly and imperfectly, forming a creamcolored mixture in which remain many small pieces of the clay 

that have not disintegrated. From the liquid mixture a flocculent 

sediment settles very rapidly. Under the microscope the clay shows 

granules of very fine kaolinite of about 0.003 millimeter in diameter, 

a fairly large number of flakes about 8 or. 10 times as large, some 

wormlike groupings, many of them 0.05 millimeter in length, 

numerous tiny shreds of altered mica, a few small grains of quartz. 

Numerous small black grains, probably of rutile, are present. Tiny 

masses of limonite are scattered here and there through the clay, 

and many of the grains of kaolinite are stained with the same substance. The pink tinge of the clay is no doubt due to the limonite.

The yellow clay is also smooth and dense, but it is a little softer 

than the white variety. It slakes poorly, leaving much unslaked 

material after several days contact with water. The suspension 

is chrome-yellow. Under the microscope the yellow clay is seen to 

differ from the white variety mainly in the darker staining of the 

kaolinite. There is also a little more mica in this variety and a 

greater abundance of grains of rutile. Moreover, the rutile is very 

much coarser, some of the grains measuring 0.05 millimeter in 

diameter.

The pink clay is also smooth, but is more granular and a little 

softer than either of the other varieties. When mixed with water it 

slakes easily and forms a very smooth suspension of a deep old-rose 

color. When treated with hydrochloric acid the clay bleaches white 

and the yellow solution produced reacts for iron. Under a low' 

magni-fying power the clay is seen to contain many little clumps of 

red limonite, or some other nearly related compound, some of which 

measure as much as 0.1 millimeter in diameter. Under high powers 

the purple clay shows the same structure as the white variety, but 

many tiny grains of a red mineral which forms the little clumps 

of limonite referred to above are visible. Moreover, the kaolinite 

is surface stained. The color of the clay seems, however, to be due 

largely to the tiny red particles that occur everywhere between the 

particles of kaolinite/

The property is about 2 miles from Crofts, on the Southern 

Railway.
222 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

\ 

SOCIETY HILL, CHESTERFIELD COUNTY.

Coker property. Mr. T. H. Coker, jr., of Hartsville, reports exposures of white clay in a number of places within a tract of 400 

acres, about 5 miles northwest of Society Hill and 4| miles north 

of the south line of Chesterfield County, in the area underlain by 

Middendorf beds. The property is about 2 miles west of the road 

between Society Hill and Chesterfield and about 3 miles from the 

Atlantic Coast Line Eailroad. Borings indicate that the clay bed 

is more than 9 feet thick under about 100 acres. Samples sent by Mr. 

Coker are slightly gritty and of a very pale pinkish gray. The clay 

separates from the mixture very rapidly, forming a granular precipitate that is rather dense. This precipitate consists of grains of 

kaolinite 0.003 to 0.005 millimeter in diameter, many particles of 

partly decomposed feldspar, 0.03 to 0.1 millimeter in diameter, a 

few tiny grains of quartz and here and there a shred of mica. All 

the larger particles are stained reddish brown.

ETJTAW FORMATION.

The Eutaw formation consists chiefly of more or less glauconitic 

sand, massive and cross-bedded, in places interbedded with thin 

layers of clay, some of which are lignitic. Locally the beds are calcareous, especially in the Chattahoochee region of Georgia. The 

beds are believed to be of shallow-water marine origin, and the total 

thickness of the formation is 400 to 500 feet.95

The Eutaw rests conformably on the-Tuscaloosa and is overlain 

conformably in part by the Selma chalk arid in part by the Bipley 

formation. It forms a narrow belt that extends from central Tennessee to central Georgia and probably is represented at least as far 

north as Trigg County, Ky.98 It is possible to subdivide it into 

two members, the Coffee sand and the Tombigbee sand, but in the 

present discussion these have no special application.

It is essentially a sand formation, and although in places it con- 

' tains thin layers of clay, so far as known these have no great value.

SELMA CHALK.

The Selma chalk extends from Tennessee to central Alabama, but 

it is thinner in Tennessee and northern Mississippi than it is elsewhere.

As it overlies the Eutaw, its area of outcrop is west of that of the

Eutaw in Tennessee and south of it in Alabama.

65 Stephenson, L. W., Cretaceous deposits of the eastern Gulf region: U. S. Geol. Survey Prof. Paper 81, p. 20, 1918.

94 Berry, E. W., U. S. Geol. Survey Prof. Paper 112, pp. 12, 13, 26-29, 1919 ; Stephenson, L. W.. and Wade, Bruce, Idem, map, 1919.
SEDIMENTARY CLAYS. 223

It consists in most places of more or less clayey and sandy limestones, which are generally chalky but may contain hard layers.

The chalky beds merge along the strike in either direction into 

nonchalky deposits, which in northern Mississippi and Tennessee are 

included in the Eutaw and Ripley formations, whereas in eastern 

Alabama they are entirely included in the Kipley.97

The Selma chalk carries no clays of value, although in Tennessee 

it contains impure clay. Nelson there refers to it as the Selma clay,08 

but he considers that it does not fully correspond to the Selma chalk 

as it is known in Mississippi and Alabama but is possibly the equivalent of the beds that form the middle portion in those States. This 

clay in Tennessee outcrops in a belt 8 or 10 miles wide, which begins 

at the Mississippi border and extends halfway across the State or 

nearly as far as the Eutaw formation. It is generally black when 

wet but leaden-gray or greenish when dry, the greenish, color being 

due to grains of glauconite. The beds may be very sandy and fossiliferous and may also in places contain limestone layers. The clay 

is well exposed in McNairy County in the Blue cut on the Mobile & 

Ohio Railway.

The clays of the Selma chalk are not of high grade, and their occurrence in Tennessee is mentioned only so that they may not be 

mistaken for the higher-grade clays that lie to'the west.

RIPLEY FORMATION. 

DISTRIBUTION AND CHARACTER.

The Ripley formation, which is the uppermost division of the Cretaceous in the area where it is found, extends from central Georgia 

through Alabama and Mississippi and then swings northward across 

Tennessee and Kentucky and into Illinois.

The typical beds of the Kipley in Mississippi, Tennessee, Kentucky, 

and Illinois consist of

more or less calcareous and glauconitic sands, sandy clays, impure limestones, 

and marls of marine origin, reaching an estimated maximum thickness in this 

region of 250 to 300 feet.

The formation rests * * * in part upon Paleozoic rocks, in part upon 

the Eutaw (in Tennessee) and in part upon the Selma chalk. From Tennessee 

and northern Mississippi southward the successively higher beds merge along 

the strike into the chalky limestones of the Selma formation. Northward the 

typical beds of the Ripley formation are believed to merge horizontally into 

a series of sands and clays of shallow-water origin, to which the name McNairy 

sand member is given.

The formation is overlain unconformably by Tertiary beds of Eocene age."

97 Stephenson, L. W., Cretaceous deposits of the eastern Gulf region : U. S. Geol. Survey Prof. Paper 81, p. 21, 1914.

98 Nelson, W. A., Clay deposits of west Tennessee: Tennessee Geol. Survey Bull. 5', 1911.

99 Stephenson, L. W., Cretaceous deposits of the eastern Gulf region: U. S. Geol. Survey Prof. Paper 81, p. 21, 1914.
224 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

In Alabama and in the Chattahoochee region in Georgia the Ripley 

resembles that of the type region in northern Mississippi. The thickness in the Chattahooche region is 950 feet. In Alabama and 

Georgia the Ripley rests conformably on the Eutaw, but along the' c 

strike westward in Alabama the successively higher beds merge into 

the Selma chalk. The formation is overlain conformably by Eocene 

beds.

On the whole the Ripley does not offer a promising field for the discovery of high-grade clay. Some clays of refractory character havQ 

been found in it in Georgia and Tennessee and are mentioned below.

GEOEGIA.

Veatch* states that the lower part of the Ripley formation, known 

as the Cusseta sand member, contains deposits of white refractory 

clay. These deposits occur in pockets that are comparatively small 

in area and may contain sand partings or grade into sand. Some 

of the pockets may be as much as 20 feet in thickness.

Occurrences have been described from Fort Valley, Perry, and 

Bonaire, in Houston County, and Marshallville and Maverick, in 

Macon County.

These clays, although refractory, do not burn white, nor can they 

be considered as refractory bond clays because of their low tensile 

strength. Most of them show mottlings of purplish or reddish color. 

The best known development is at a locality 3 miles north of Perry, 

Houston County, where the Houston Kaolin Co. has started operations. The clay outcrops in the side of a ravine and the section in 

the face of the excavation shows the following beds:

Section in pit of Houston Kaolin Qp., north of Perry, Go,.

Feet.

Ferruginous sands_____________________ 8-10 

Mottled clay___________________________ 8 

Whitish clay_________________________ 10

As the hillside rises steeply the thickness of the overburden increases to a marked extent in a short distance. Grains of pyrite are 

visible in the mottled clay, and even the lower clay may show them.

The clay is very dense and breaks with a conchoidal fracture. 

The texture is quite uniform. A microscopic examination of the 

mottled clay showed very little difference between the red and the 

white parts. On the whole the clay is composed chiefly of exceedingly fine grained, mostly unidentifiable particles, and the red material is stained with hematite. A few grains of quartz were present, 

Borne of them being much larger than the other mineral grains.

1 Veatch, Otto, Second report of the clay deposits of Georgia: Georgia Geol. Survey 

Bull. 18, 1909.
SEDIMENTARY CLAYS. 225

There were a few grains of hydromica and kaolinite. The red material showed a few grains of rutile, but the white material showed 

numerous tiny grains of this mineral as well as some zircon.

Tests by the Georgia Geological Survey show that the clay burns 

a faint cream color at cone 9 (1,310° C.) and has 11.8 per cent fire 

shrinkage. Its fusion point lies above cone 33 (1,790° C.). This 

deposit was not operated in 1918 and had apparently been idle for 

some time.

TENNESSEE.

The Ripley formation extends across the State of Tennessee in a 

belt which ranges from 15 miles in width on the southern boundary 

to 6 or 8 miles on the northern boundary. It crosses the counties 

of Hardeman, McNairy, Chester, Henderson, Carroll, Benton, and 

Henry. (See PI. XVII.)

The formation consists mostly of stratified sands of different 

colors, between which occur beds of gray lignitic or yellow sandy 

micaceous clay. The sands are somewhat extensively stained with 

iron, and on this; account commonly resemble those of the overlying 

so-called " Lafayette formation." This iron in many places cements 

the sands and causes the development. of curious pipelike forms.

Two occurrences of refractory bond clays have been located in the 

Kipley formation, one of them near Hollow Rock, in Carroll County, 

and the other near India, in Henry County.

HOLLOW ROCK, CABBOLL COUNTY.

All the clays worked around Hollow Bock are in the Ripley formation and are mostly of the sagger and wad type, although some 

ball clay is also dug. The pits are rather small. Two of them were 

visited.

One of these pits is operated by the National Sales Co. and A. Nunnelly on the land of Harvey Hodge, 1^ miles northeast of Hollow 

Rock station. The pit shows a circular working face about 200 feet 

long and 15 feet high. The clay, whose section is shown in figure 33 

(No. 1), is mostly dark gray, but the upper 5 feet is much lighter 

in color and is not so clean as the lower part.

This lighter color is due to weathering, which has also, caused the 

development of mottlings of limonite in the joint fractures.

There are no visible streaks of sand, but grains and small lumps 

of lignite are scattered through the clay. These particles, however, 

would burn out in the kiln. Certain layers also contain impressions 

of leaves, but these are not harmful.

In the hand specimen the clay appears gritty and shows tiny scattered scales of mica. Under the microscope this clay is seen to be 

medium to coarse grained.
226 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Quartz is common; hydromica abundant; kaolinite common; rutile 

is abundant in small needles and grains; tourmaline is present but 

rare.

Hollow Rock, Tenn., 

A.. Nunnelly

5 iniles east of Paris, Tenn. 

Johnson-Porter Clay Co., 

 -Currier pit

India, Tenn.,. - 

Handle Clay Mining Co., 

' No. 3 pit

Weathered day 1-5'

Dark clay'10-lV

Yellow clay l' 

White sand, 

thickness unknown

L$ht-yellow , , 

clayey sand 6-9

Li$hWray day (ball) y-5' 

Thia sand layer I"

Black day'4' 

li$ht sandy clay 1-3' 

Sandy, bottom not seen

Soil , , 

Sandy .red clay m-2

Orange-colored sand 10'

u^frrTj.-.-.-.-.-.-.-.-.-.-jji Dark orange-colored sand I*

^S-I^^^^L^fitic clay 4" 

Sandy clay and 

loose sand 5-6'

inks

.6

isbui 

Paducah Clay

Briensburg, Ky., 

ih Clay Co.

^^i£j£>:w[ww£:£

India, Tenn.,

Mandle Clay Mining Co.,

Old pit No. 3

Gravel, 10' maximum

La$ran|e sand, 8' 

maximum

Bluish-black day 

with $auconkic 

sand laminae 

near bottom 38-39'

Black day (ball).t0'8"

Dark clay (not seen) 2' 

-Thin lignitic seam

, ickness unknown

Orange-colored 

sand 17'

Benton.Ky.,

Paducah Clay Co.,

Howard pit

clay film IV 

Gray elay 7'4"

{

Black loamy clay with pyrite and , 

ii^nitized wood Z 6

Blue plastic clay 3'6"

Yellowish sand and clay f 6" 

Brown clay, , , 

iron streaks 2 6 

Black clay

LoamE' 

Gravel 6"

Alternating bands of 

light and dark sand .

Clay exposed l)fe-2' 

Rest is black

and. sa^er clay

Yellow sand, 

thickness unknown

FIGURE 33. Columnar sections in the Ripley and Porters Creek formations of western

Tennessee and Kentucky.

The light and dark grades of clay are separated for shipment, and 

the pit supplies sagger clay and ball clay that is known as No. 291.

The following tests of clay from the -Nunnelly pit, commercially 

known as No. 291, were supplied by the Tennessee Geological Survey:
U. S. GEOLOGICAL SURVEY BULLETIN 708. PLATE XVII

90°

MAP OF

PART OF WESTERN KENTUCKY 

AND WESTERN TENNESSEE

Showing location of worked clay deposits

and prospects

Scale Tdooobo

R A Tf B S S

ID 20 30 40 5O ifilometeTS

W«k«,-V&ll«v r ^ 'IrWv

I ' \ I \

EXPLANATION

Worked clay pit

Abandoned clay pit

Prospect 

or promising outcrop «i

90°

LIST OF LOCALITIES.

(The active pits from field 

notes of H. Ries and C. 

W. Parmelee.

The prospects and abandoned pits chiefly from 

Tennessee Geological 

Survey.)

1. Cooley Ball & Sagger 

Clay Co., pitsNos. 9, 

10, and 11.

2. Dixie Brick & Tile Co.

3. Dixie Brick & Tile Co.

4. Mandle Clay Mining 

Co., Monroe pit.

5. Sanders & Nealy, 

Bradlee pit.

6. Mandle Clay Mining 

Co., Cole pit.

7. Mandle Clay Mining 

Co.

8. Johnson-Porter Clay 

Co.

9. Mandle Clay Mining 

Co., Wade or No. 4 

pit.

10. Jackson pit.

11. Galloway County Clay 

Co.

12. United States Clay Co.

13. H. C. Spinks, Hilltop 

mine.

14. H.C. Spinks Clay Co. 

and W. Aliison, Mill 

pit.

15. Mandle Clay Mining 

Co., No. Spit

16. S. & J. Jackson.

17. Mandle Clay Mining 

Co., Barbee pit.

18. Johnson-Porter Clay 

Co., Jackson or Porter's pit.

19. H.C. Spinks Clay Co., 

Jernigan pit.

20. J. C. Strop.

21. H.C.SpinksClayCo., 

Atkins pit.

22. C. Sparks.

23. H.C.SpinksClayCo., 

Grable pit.

24. H.C.SpinksClayCo.

25. Johnson-Porter Clay 

Co., Dalton pit.

26. Johnson-Porter Clay 

Co., Williams pit.

27. Scates-Reynolds Clay 

Co.. Breedlovepit.

28. McNanee pit.

29. A. P. Diggs pit. '

30. A.Nunnelly & National Sales Co., Hodge 

pit,

31. G. M. Bennett pit.

32. H. M. Cooper.

33. Johnson-Porter Clay 

Co., wad mine.

34. J. F. Dale, sand pit.

35. Colonial Clay Co.

36. Paducah Clay Co., Lofton pit.

37. Kentucky Construction & Improvement 

Co.

38. May field Clay Co.

39. Old Hickory Clay & 

Talc Co.

40. American Clay Co.

41. St. Louis Clay Co.

42. Paducah Clay Co., 

Howard pit.

43. Paducah Clay Co., 

Briensburg pit.

44. Excelsior Clay Co.
SEDIMENTABY CLAYS. 227

General physical tests of clay from Nunnelly pit, Hollow Rock, Tenn.

Working property _______________Good, somewhat sticky.

Water of plasticity__ ______________per cent 31.6

Modulus of rupture:

Haw clay_________;__pounds per square inch__ 112.0 

Mixture of clay and sand in proportion of 1:1 do 112.0 

Slaking test____________________minutes__ 5. 0

Fineness test:

20-rnesh sieve __________________- __No residue. 

40-rnesh sieve ____ ________________*_No residue. 

60-mesh sieve__________________________Trace. 

80-raesh sieve_________________________Trace. 

Residue, 120-mesh sieve, mica and sand ___per cent 0. 46 

Residue, 150-mesh sieve, mica and sand_!_ _do__ . 50 

Residue, 200-mesh sieve, mica and sand _____do__ .60

Drying shrinkage, linear ______________ _do__ 6. 8

Fire tests of cUy from Nunnelly pit, Hollow Rock, Tenn.

Total 

Color. Hardness. shdnKage

Cone2 (1,170°C. ...................... White............. Steelhard......... 16.5 28.0

Cone5 (1,230° C. ...................... .....do............ .....do............ 13.7 28.0

Cone9 (1,310°C. ...................... Light cream....... .....do............ 14.7 22.1

Cone 12 (1,370° C.)............. .... .....do. . ........ ..do............ 15.8 8.5

Conel3 (1,390°C.)..........,....!..... ........."........... .....do............ 16.2 11.4

Fusion test: Deforms at cone 31 (1,750° C.).

This clay burns to a good color at the temperatures indicated in 

the table. It is rather open burning for a ball clay, and the strength 

of the unburned clay is only fair. It is more of a semiball clay in 

nature than a ball clay. It will doubtless be of service in the manufacture of certain grades of chemical stoneware, sanitary ware, terra 

cotta, face brick, and saggers, and possibly it will find some use as a 

bonding material in the manufacture of certain refractories which 

are not expected to stand exceedingly high temperatures.

The pit of H. N. Cooper lies about 1£ miles south of Hollow Rock 

and one-fourth of a mile east of the Nashville, Chattanooga & St. 

Louis Railway. It covers about an acre and has a diameter of about 

200 feet.

According to Mr. Cooper the clay underlies 30 to 40 acres, and a 

boring made about 1,000 feet to the east of the pit penetrated it to 

a depth of 16 feet under 8 feet of overburden, but definite evidence 

that the clay extends continuously from this point to the pit is .not 

at hand.

The section in the pit shows a maximum of 18 feet of clay overlain 

by 4 to 5 feet of loamy overburden and underlain by sand. Scattered 

nodules of pyrite are found in the lower part of the clay.

The clay is dark gray-brown and stratified. The hand specimens 

show a faint banding. It runs fairly uniform in texture, although
228 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

on the south side of the pit there are narrow vertical cracks that 

are filled with limonite.

A microscopic examination of the clay revealed a medium texture. 

Quartz was common, and both hydromica and kaolinite were abundant. Rutile in tiny grains was very common, but only two or three 

grains of tourmaline were observed.

A section of the burned clay showed that, although the micaceous 

texture remains, all the interference colors of the hydromica had 

disappeared, the grains showing instead a low interference color 

similar to that of kaolinite. Very little of the groundmass was 

isotropic. The grains of quartz were still visible, although some of 

them showed corrosion.

When wet the clay is very plastic and feels smooth.

One sample fired at 1,180° C. had 14.5 per cent absorption, and a 

second fired at 1,300° C. had 4.4 per cent absorption and 9.1 per 

cent porosity. The burned product was steel hard and *buff.

The clay is hauled by wagon to a siding 250 yards distant and 

shipped to Nashville, Tenn., and Atlanta, Ga., for use in brick and 

terra cotta. It could probably be utilized also for saggers. The 

pit has been in operation about six years.

The following tests of H. N. Cooper's clay were supplied by the 

Tennessee Geological Survey:

General ^physical tests of sagger clay from E. N. Cooper's pit, Hollow Rock, Term.

Working properties________________________ Good.

Water of plasticity ____ _per cent__ 33.9

Modulus of rupture:

Unburned clay ___pounds per square inch__ 115 

Mixture of clay and sand in proportion of 1:1__do__ 86.2

Slaking test _ _______minutes.. 6

Fineness test:

20-mesh sieve __ ______________ No residue.

40-mesh sieve______________________ No residue.

60-mesh sieve___________-_________ No residue.

80-mesh sieve___________;_________ No residue.

Residue 120-mesh sieve.________ Trace, chiefly mica.

Residue 150-mesh sieve-____ _____per cent__ 0.04 

Drying shrinkage, linear- ______________^_do__ 5.8

Fire tests of sagger"clay from H. N. Cooper's pit, Hollow Rock, Tenn.

Total

Color. Hardness. shrinkage 

(percent).

Cone2(l,170°C.).......,............... Pinkish........... Steelhard......... 10.0 29.1

Cone5 (1,230* C.)....................... .....do............ .....do............ 11.5 25.0

ConeO (1,310* C.)....................... Darkgray......... ...do............ 13.5 6.1

Cone 12 (1,370°C.)...................... .....do............ .....do............ 13.7 5.1

Conel3 (1,390° C.)...................... .................... .....do............ ............ 11.4

Fusion test: Deforms at cone 30 (1,730° C.).
SEDIMENTARY CLAYS. 229

The clay shows a good vitrification at cone 9 (1,310° C.). The 

color is fair and the strength is fairly good. It will probably be 

of service in the manufacture of terra cotta, sanitary ware, face 

brick, and saggers. It is doubtful if the color is satisfactory for 

use as a ball clay.

INDIA, HENRY COUNTY.

About 1£ miles east of India the Handle Clay Mining Co. has two 

active pits, known as the No. 3 and the Barbee. They lie on the 

western edge of the Kipley formation and hence are in its upper part, 

because the beds dip westward.

Several other pits have been opened here in close proximity to 

each other, as new pits were opened when the old. ones were worked 

out.

The section in pit No. 3, which was being worked in 1918, is shown 

in figure 33 (No. 3). About 20 feet is stripped off before the best 

black ball clay is reached. These two pits yield several grades of 

clay, known as " Tennessee Ball Nos. 3 and 6," " Glasspots," " Barbee 

special," and " Special sagger clay."

The black clay consists chiefly of kaolinite and hydromica, all 

stained dark with very fine grained organic matter.

A neighboring worked-out pit, shown in figure 33 (No. 4), illustrates how the section may change in a distance of a few hundred 

feet.2 The blue clay is the best in the pit and contains the least 

amount of sand. It changes gradually into the brown bed beneath it, 

which represents a fairly good ball clay.

All the clays dug in this locality for commercial use have a high 

content of organic matter.

A sample of the ball clay No. 3, as tested by Nelson, gave 10 to 15 

per cent residue, mainly silica, on a No. 12 sieve. The clay is very 

plastic and carries 72 per cent of flint. At cone 1 (1,150° C.) its 

shrinkage is 12.5 per cent, and at cone 8 (1,290° C.) it is 18 per cent, 

the body being of a grayish-white color.

Another pit in the Ripley formation is that operated by the JohnsonPorter Clay 'Co., 5 miles east of Paris, Tenn., which is known as the 

Jackson or Currier pit. A generalized section in this pit is shown 

in figure 33 (No. 2). The beds, however, are not uniform throughout 

the pit, which is about 350 feet long and 50 feet wide. The thickness 

of the clay ranges from 7 to 16 feet, although the maximum exposed 

at the time of the writer's visit was 10 feet. The upper 3 to 5 feet 

of light-gray clay, known as Jl, is sold as ball clay, and the black 

clay, which shows yellow and red stains and which is of the ball-clay 

type, is said to be sold as sagger clay. The best clay occurs in the 

center of the pit.

8 Nelson, W. A., Clay deposits of west Tennessee: Tennessee Qeol. Survey Bull. 6, p. 89, 

1911.

77412 22 17
230 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Two samples of the clay were examined microscopically. One of 

these samples is a specimen of the clay known as the black clay. It 

is medium grained, and in it grains of quartz and kaolinite are common and hydromica is abundant and commonly coagulated. Kutile 

is scarce. The hand specimen shows a few grains of lignitic material 

and also a few scattered flakes of mica.

In the brown sandy bottom clay also quartz is common but fine 

grained. Kaolinite is abundant, and hydromica a little less so. 

Kutile is present in numerous needles and grains, but tourmaline and 

titanite though present are rare.

It is claimed that this deposit contains 140,000 tons of clay.

TERTIARY OLAYS. 

DISTRIBUTION.

Formations of Tertiary age are distributed throughout the Coastal 

Plain and Embayment Area from New Jersey to Illinois, but those 

that contain clays of the types discussed in this report have been 

found only in South Carolina, Georgia, Florida, Mississippi, Tennessee, Kentucky, Illinois, and Arkansas. In these States refractory 

clays occur at a number of places. Some of them are of value because 

of their whiteness in either the raw or the burned condition, and 

others belong to the class of refractory bond clay.

Occurrences of the white-burning clays are, however, of little importance in the present discussion, except those in Florida. The 

clay from the Tertiary deposits of Georgia is white only in its unburned condition. That from the other States burns cream-white 

or bluff but has high bonding qualities.

The high-grade clays do not occur in the same division of the Tertiary in every State, although the majority are found in the Wilcox.

The deposits- will be described by formations, where these are 

known.

EOCENE (?) CLAY. 

SOUTH CAROLINA. 

By W. S. BAYLEY.

Abbeville, A'b'beville County. No high-grade clays of undoubted 

Tertiary age are known in South Carolina, and the following clay, 

which may be of Eocene age, is placed here provisionally. It lies 

within the area of crystalline rocks west of the fall line, on the property of J. A. and W. E. Hill, 2£ miles south of Abbeville. This 

property has already been referred to in connection with the occurrence of kaolin (p. 80).

The Tertiary clay is exposed on the east side of the road, in gullies 

cut in the fields. The best exposure is about 300 yards southeast of 

the pit on the road, where there is a gully cut 4 or 5 feet into a
SEDIMENTARY CLAYS. 231

sticky granular, very gritty whitish clay overlain by alternating 

thin layers of limonite and sandy clay. Farther south in a branch 

of the same gully is another exposure, where the clay is several feet 

thick. The clay is grayish pink and putty-like, resembling " fuller's 

earth " in many respects. It overlies a coarse sandstone or granite 

but is not a product of its decomposition. Plainly both of the deposits east of the road are sedimentary, and both are Eocene or 

Recent. The composition of the whitish clay as determined by 

Brackett is as follows:

Analysis of white clay from Hill property, 2% miles south of Abbeville, S. C.

Silica (Si02 )____________________________ 72.10 

Alumina (A1203 ) _________________________ 16.12 

Ferric oxide (Fe2 03 )________ _ __________ 2.48

Lime (CaO)________ __ 1.20 

Magnesia (MgO)_______:_____:__ .21 

Soda (Na2 0)______________________________ .96

Potash (KaO) ___________________________ 1.85 

Manganese oxide (MnO)___________________Trace. 

Titanium oxide (Ti02 )____________ _____Trace. 

Water (H2 0)______-_____________________ 5.30

100. 22

The composition shown in the table corresponds to 36.75 per cent 

of quartz, 29.25 per cent of feldspar, and 34.22 per cent of clay 

substance.

When mixed with water the clay works up into a grayish-white 

mass from which a fine sand separates. When examined under the 

microscope its components show that they have been subjected to 

sorting. The grains of quartz are clear and colorless and are much 

more uniform in size than those of the clay from the pit on the road. 

They range in general from*0.05 to 0.1 milimeter in diameter, though 

there are a few grains above or below these limits. Most of them 

are irregular in shape, but by no means so ragged as those in the 

kaolin at the road. Moreover, very few grains of white feldspar 

are present and only here and there a grain that is colored brown. 

The mica is white and colorless, and its grains are abundant. The 

kaolinite presents no peculiar features. The proportion of large 

plates and of aggregates of plates is much smaller than in the residual kaolin in the road, and the average size of the plates is less. 

Only a very few broken wormlike and rosette aggregates are noticeable.

The microscopic features of the clay are those that might be 

expected in one that originated in the transportation for a short distance of the constituents of a residual clay, like that at the road.

The " fuller's earth" was tested on cottonseed oil by Mr. J. H. 

Mallory, of Columbia, who reports that it filters as rapidly or only
232 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

slightly more slowly than English fuller's earth and produces a 

clearer and whiter oil. Burning tests made by the Norton Co. in 1917 

gave the following results: Shrinkage on drying, 10 per cent; on 

burning, 13 per cent. Plasticity, good. The clay burned at cone 13 

(1,390°C.) gives a product that is dense and so hard that it can not 

be scratched; bending strength, 53.8 pounds to the square inch.

The following tests of a sample of white clay (Bureau of Mines No. 

1.57) from this pit has been supplied by the laboratory of the Bureau of Mines at Columbus, Ohio:

General physical tests of sample of clay from pit of J. R. & W. Hill Co., Abbeville, 8. C.

Workability _ Plasticity low; gritty; corners tear; dries well. 

Water of plasticity, in terms of dry clay_____per cent__ 32. 50 

Air shrinkage by volume________________do__ 11.46

Air shrinkage, linear, calculated____________do__ 4.00

Fire tests of sample of clay from pit of J. R. & W. Hill Co., Abbeville, S. C.

Temperature (°C.).

1,190.............................

1,250.............................

1,310.............................

1,370.............................

1,410.............................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

30.90

29.20

26.58

.20

.00

Color.

.....do................................

Olive-buff. ............................

Volume 

shrinkage 

(p.er cent 

in terms 

of volume 

of dry 

clay).

8.00

12.20

17.24

30.50

30.90

Linear shrinkage, calculated (per 

cent).

2.7

4.6

6.1

11.4

11.6

Cone of fusion, 27.

A sample of this clay was used in a porcelain body and gave the 

results noted below :

General physical tests of porcelain body containing clay from pit of J. R. & W. 

Hill Co., Abbeville, S. C.

Water of plasticity, in terms of dry clay_____per cent__ 31. 34

Volume shrinkage ________________do__ 13.59

Air shrinkage, linear, calculated___________do__ 4.8

Modulus of rupture. _______pounds per square inch_ 197.6

Fire tests of porcelain body containing clay from pit of J. R. & W. Hill Co.,

Abbeville, S. C.

Temperature (°C.).

1,190...................

1,250...................

1,310...................

1,370...................

1,410...................

Porosity 

(per cent 

in terms 

of volume 

of burned 

clay).

14.60 

11.07 

1.82 

2.49 

25.90

Color.

Ivorv~vcllow

Gray..................................

Tvnrv-vfillnw

Volume 

shrinkage 

(percent 

in terms' 

of volume 

of dry 

clay).

16.90 

20.76 

27.58 

17.49 

10.50

Linear 

shrinkage, calculated (per 

cent).

6.0 

7.5 

10.2 

6.2 

3.6

Modulus 

of rupture 

(pounds 

per 

square 

inch).

2,946 

4,489 

5,228 

4,047 

1 973
SEDIMENTARY CLAYS. 233

The location is convenient for mining. Water would have to be 

pumped 90 feet, but water from the mine would flow to Abbeville, 

2| miles distant, where shipment could be made either by the Southern Railway or the Seaboard Air Line. The refined clay might also 

be trucked three-fourths of a mile to the Seaboard Air Line, south of 

Abbeville.

MIDWAY GROUP. 

GEORGIA.

Of the several divisions of the Tertiary deposits that underlie the 

Coastal Plain of Georgia, the Midway 3 and Wilcox are the only 

divisions that contain high-grade clays of promise. In Georgia these 

deposits form a belt 10 to 15 miles in width, which extends from Fort 

Gaines, on Chattahoochee River, northeastward to Montezuma, on 

Flint River, and perhaps even northward into Houston County. 

They rest in contact with the underlying Upper Cretaceous sands 

and marls and occupy parts of Clay, Quitman, Randolph, Stewart, 

Webster, Schley, Sumter, and Macon counties. .

Spencer estimates their thickness along Chattahoochee River as 

618 feet, but it probably diminishes northward.

These deposits as a whole carry clays of varying quality, sands, 

and limestones. The deposits of white clay are not widely distributed, but where present they may be extensive. Large beds occur 

at Kelly Mill and Copperas Bluff in Sumter County, and in Stewart, 

Randolph, and Quitman counties white clays occur in the sands, but 

these deposits are in the form of lenses or irregular pockets which 

are not very persistent, although some of the pockets reach a thickness of 12 to 15 feet or even more.

The white clays are massive and not as pure as those of the Lower 

Cretaceous. The plasticity is good, the fire shrinkage and the refractoriness high, and the tensile strength low.

These clays have not been used.much if at all. They do not burn 

as white as the Lower Cretaceous clays of Georgia, but as they are 

white in their unburned condition they might possibly serve in the 

manufacture of paper, paint, linoleum, or rubber. In their burned 

form they might be used in electrical porcelain.

The following table gives the tests made by Veatch on some of 

these clays in Georgia.

 Veatch, Otto, Second report on the clay deposits of Georgia: Georgia Geol. Survey 

Bull. 18, 1909. Most of the data here given are from this report, in which Veatch Included both the Wilcox and the Midway in what he described as " Midway formation."
234 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES. 

Physical tests of Midioay and Wilcox clays from Georgia.

Slakes....................

Per centof material passes

Plasticity.................

Tensile strength in pounds 

per square inch. .........

Air shrinkage, per cent.. .

Burning tests: 

Cone 4 (1 210"C.): . Fire shrinkage, per

Color.............

Cone 9 (1.310°C.): 

Fire shrinkage, per

Color.............

Cone 13 (1,390°C.): 

Fire shrinkage, per 

cent............

Color.............

Fusion cone..........

1

90.......................

14.......................

5.7......................

42.......................

t 

^.l. .....................

l\.\.. ...................

13.4.....................

2

37.......................

6.2......................

43.......................

11.9.....................

30+.....................

3

Low.

6.

52.

10.8.

22.2.

1. Kelly Mill, Sumter County. 2. Copperas Bluff, Sumter County. 3. Moye property, 5J miles north 

of Cuthbert, Randolph County. Checks badly. Almost impervious at cone 9. This clay is now classed 

as Wilcox, but as it is similar in many respects to Nos. 1 and 2, it is included in the table.

An interesting deposit of white clay, according to Shearer,4 overlies the bauxite at the Sweetwater bauxite mine, of the Republic 

Mining & Manufacturing Co., 5^ miles east of Andersonville. The 

clay has a maximum thickness of 20 feet and tapers down to a thin 

edge. It is overlain unconformably by sand, which is as much as 

30 feet thick in places. Here and there the upper 2 feet or more of 

the clay is stained and mottled red and purple, but the rest is pure 

white. The mottled clay contains grains of pyrite.

At the time of the writer's visit the clay was exposed for a distance of about 400 feet. It was 8 feet thick at the southeast end 

of the pit and 20 feet at the north end. No attempt is made to utilize 

it, and it is stripped off to get at the bauxite. (See PL XV, #, p. 197.)

The white clay is dense, fine grained, and brittle. When, thoroughly slaked down and mixed with water it has very fair plasticity.

Under the microscope it is seen to be very fine grained. Kaolinite is abundant, and hydromica is common, but its interference 

colors are a little lower than usual. A few tiny prisms of rutile and 

tourmaline are present.

The red clay is also very fine grained and contains much finegrained indeterminable material which is stained with iron. There 

are numerous small grains of a mineral that is probably kaolinite, 

but hydromica is scarce. A few grains of chlorite, zircon, and rutile 

were seen.

Two samples were fired with the following results:

* Shearer, H. K., A report on the bauxite and fuller's earth of the Coastal Plain of 

Georgia: Georgia Geol. Survey Bull. 31, p. 66, 1917.
SEDIMENTARY CLAYS. 235 

Fire tests of white clay, Siveetwater mine, east of Andersonville, Oa.

Temperature ( 8C.).

1,150...................................................

1,300. ...................................................

Absorption 

(per cent).

26.9

16.4

Porosity 

(per cent).

43.7

33.1

Color.

Faint cream white.

A section of the clay which was fired at the lower temperature 

showed a very fine granular aggregate that consisted half of isotropic 

material and half of grains that showed the interference color of 

kaolinite. Another section which was fired at the higher temperature was similar to the first but was beginning to develop matted 

patches that had low interference colors.

The clay could be shipped as well as the bauxite.

MISSISSIPPI.

The Midway group forms a narrow belt which extends across 

northeastern Mississippi. It enters the State in Kemper County and 

passes out in Tippah County. The upper formation of the group is 

the Tippah sandstone of Lowe,5 and the underlying formation is 

known as the Porters Creek ("Flatwoods") clay. These clays are 

gray, laminated, and somewhat shaly, commonly micaceous, and bear 

abundant iron-stone concretions in their upper part. They form leneshaped deposits.

The analyses given by Logan all indicate a high content of iron, 

and no high-grade clays have been found, although the same formation farther north has much better-grade materials;

There is a possibility, however, that tKe Porters Creek may carry 

some clays similar to those found near Benton and Briensburg, Ky. 

(pp. 236-238).

One sample collected from Flatwoods, near Kipley, Tippah 

County, fuses at cone 28 (1,690° C.) and has a transverse strength 

of 469 pounds to the square inch.

E. N. Lowe communicates the following notes regarding this deposit :

One and one-half miles north of Ripley, on the west side of the Gulf, Mobile 

& Northern Railroad, an outcrop of gray clay occurs in the public road 40 rods 

west of J. F. Conner's sawmill. The surface formation here is the heavy, 

sticky gray clay soil of the Porters Creek formation of the Midway, which outcrops over a zone of low flat country 4 to 6-miles wide. On slopes the soil Is 

removed and the unweathered gray Porters Creek clay is exposed.

This clay is light gray and very plastic and has no visible impurities except 

slight yellowish mottlings of iron where it is weathered; locally the clay, owing 

to its content, of lignitic matter, becomes darker. The typical clay, as at the 

exposure where the sample was taken, shows jointing into small concretionary -

 Lowe, E. M., Mississippi Geol. Survey Bull. 12, p. 64, 1915.
236 HIGH-GKADE CLAYS OF THE EASTERN UNITED STATES.

like nodular masses, and these on drying show distinct conchoidal or concentric fracture, which is very characteristic.

The exposure of this clay just west of the Conner sawmill is 12 to 15 feet 

thick in washes in the slopes west of the road, but the depth below the road 

level is unknown, though it is probably at least twice the visible thickness. 

Laterally clay of apparently identical quality is exposed for miles across the 

country. This exposure is 250 yards from the Gulf, Mobile & Northern Railroad and 1$ miles north of Ripley. No pit has been opened here.

DISTRIBUTION AND CHARACTER.

The Porters Creek clay of the Midway group crosses Tennessee 6 

and Kentucky 7 in a belt that averages about 8 miles wide across 

southern Tennessee, but widens out to 10 or 12 miles in Galloway 

County, Ky. Then as it curves westward beyond Paducah the outcrop narrows and the formation is concealed by alluvial deposits of 

Ohio River before it crosses into Illinois. In Illinois it outcrops 

only along the bank of the Ohio at Caledonia Landing and for some 

distance to the north of Grand Chain. ('See PI. XVII.)

In Tennessee the Porters Creek carries a fine-grained gray clay, 

locally known as soapstone, which gets very black when wet. In the 

lower part of the formation the clay may be interbedded with a very 

fine micaceous sand, and in places it also carries beds of green sand 

or glauconite. No clays of high grade are found in the Porters 

Creek in Tennessee.

In Kentucky the Porters Creek carries clay which has been opened 

up at several localities in Marshall County, and though not of the 

best pottery grade it is nevertheless of better quality than anything 

which has been developed in Tennessee, much of it being sold as wad 

and sagger clay. The pits seen were .located chiefly near Benton and 

Briensburg.

BENTON, MARSHALL COUNTY, KY.

Of the several pits in the vicinity of Benton none were in continuous operation during 1918. The clay was dug as local needs demanded and most of the product was sent to the stoneware factory 

at Paducah.

One opening, the Howard pit, which is 1 mile northwest of Benton, 

is a shallow excavation that covers about half an acre and is not 

steadily in operation.

The total thickness of the clay is 12 feet, of which 5 to 7 feet is a 

black laminated clay and the rest is a bluish-gray sagger clay. (See 

fig. 33 (No. 5), p. 226.) The clay appears to thin out to the south.

 Nelson, W. A., Clay deposits of west Tennessee: Tennessee Geol. Survey Bull. 6, 1911. 

T Glenn, L. C., Water-Supply Paper 164, p. 29, 1906.
SEDIMENTARY CLAYS. 237

The wad clay from the Howard pit is of fair plasticity but rough 

textured and shows a few mica scales and some finely divided organic 

matter.

Under the microscope grains of quartz are seen to be fairly common, and both hydromica and kaolinite abundant. Rutile is present in numerous tiny grains and needles. A little epidote was also 

noticed.

A sample that was fired to 1,300° C. showed 12 per cent absorption 

and 24.5 per cent porosity and was buff.

A thin section of the burned clay showed many grains of quartz 

in a groundmass that was mostly isotropic, but wherever it showed 

any interference colors these were very low. The hydromica, however, has all disappeared, but the. grains of rutile appeared to be unaffected.

A sample of the lower-grade clay from the Howard pit is medium 

to fine grained. It contains thin sheets of sand along the bedding 

planes and scales of mica that are visible to the naked eye. This 

sample was also examined under the microscope and showed quartz 

grains, abundant and rather coarse hydromica, and abundant kaolinite. Rutile again was common in tiny grains and needles.

About one-fourth of a mile west of the Howard pit and along the 

highway leading north from Benton clay again outcrops in a high 

bank. There is nothing to show that it is part of the same mass that 

is exposed in the Howard pit, but if it is a part of that mass it indicates that the level of the clay surface rises considerably. If it is a 

separate deposit it must lie at a higher level than the Howard lens.

The section exposed along the highway shows the following beds:

Section along highway north of Benton, Ky.

Feet.

Sand, ash-colored and buff- 1_ _ r _____ 2$ 

Dark chocolate-colored laminated clay, of sandy and micaceous

character, with small lenses of white sand__________ 16 

Talus to road _____ '___,. _ ______ 17

41

As the surface of the hill rises away from the road and the conglomerate extends to the top, then if the surface of the clay remains 

level the overburden must reach a maximum thickness of 70 feet.

About 3| miles north of Benton are two other pits, on the Lofton 

property, both leased by the Paducah Clay Co. The clay is said to 

underlie an area of 40 acres. It is sandy, about 15 feet thick, and 

is underlain by sand. Above it lies a gravelly conglomerate and 

hardpan, whose thickness is not less than 8 or 10 feet. The pits were 

idle in June, 1918.
238 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

BRIENSBURG, MARSHALL COUNTY, KY.

The Paducah Clay Co. has opened a deposit 2 miles east of Briensburg to supply clay for making pottery.

On one side of the excavation there is a square pit which shows 39 

feet of clay. This material is black, dense, and plastic but contains 

sandy laminae from 2 to 6 inches apart. Flat concretions of pyrite 

are scattered along the bedding planes through the deposit, but these 

are thrown out in mining. Near the bottom the clay contains thin 

layers of glauconitic sand. (See PI. XVIII, A, and fig. 33 (No. 6), 

p.. 226.)

Where the clay was being dug in June, 1918, it had but 4 feet of 

overburden, but in the 10 acres that have been tested the overburden 

increases in places to 15 feet.

On the south side of the pit the section shows Lagrange sand on 

the top of the clay, which in turn is overlain by terrace gravels. (See

fig. 34.) The clay is used in stoneware and saggers.

The wad clay has fair plasticity 

but is rather coarse textured and 

contains visible scattered grains of 

mica.

Under the microscope quartz is 

quite common, and hydromica and 

kaolinite are abundant. The hydromica appears to be iron stained. 

Rutile is not very abundant, and 

there are a few grains of zircon. 

At 1,300° C. the clay burns gray-brown and has 5.6 per cent absorption and 12.9 per cent porosity. It is steel hard.

A thin section of the fired clay showed abundant grains of quartz, 

but the hydromica had all disappeared and the groundmass appeared 

to be fused.

MURRAY, GALLOWAY COUNTY, KY.

The United States Clay Co., whose office is at Indianapolis, Ind., 

owns clay pits 10 miles north of Murray, but they have not been 

regularly operated. The deposits worked at this locality are probably in the Porters Creek formation.

WILCOX GROUP. 

DISTRIBUTION.

The Wilcox group is one of the most extensive clay-bearing divisions in the Southern States. It contains clays of high grade in 

Arkansas and Mississippi and in its northward extension in Ten40 Feet

FIGURE 34. Section on south side of 

pit of Paducah Clay Ca., east of 

Briensburg, Ky. Porters Creek clay 

(c) is overlain by Lagrange sands 

(6) and these in turn are overlain by terrace gravels (a).
U. S. OEOLOGICAL SURVEY BULLETIN 708 PLATE XVIII

A. SECTION IN PIT OF PADUCAH CLAY CO., BRIENSBURG, KY. 

(See fig. 34, p. 238.)

B. CLAY PIT OF J. T. BRAMLETT, 10 MILES WEST OF ENID, MISS.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XIX

A. GULLIES NEAR HUNTINGTON, TENN., SHOWING NATURAL EXPOSURES 

OF LAGRANGE CLAYS.

S. TYPICAL SECTION OF GRAVELLY OVERBURDEN,

OFTEN CALLED "LAFAYETTE."

This material overlies the Lagrange Mays in many places in 

Tennessee.
SEDIMENTARY CLAYS. 239

nessee, Kentucky, and Illinois (PL X, p. 162), where it is represented in the Lagrange formation, of which it composes the major 

part.

The deposits comprise littoral and estuarine sediments over a wide 

area and contain many impressions of plants.8 They consist in 

general of more or less extensive lenticular beds of sands and clays. 

The sands are commonly cross-bedded and ferruginous and contain 

lenses of clay, which in places are of sufficient size and purity to 

form the basis of an important clay-mining industry.

Their occurrence in the several Stfates is referred to below.

GEORGIA.

The clays of Wilcox age in Georgia are not extensively worked. 

One is referred to on page 234.

MISSISSIPPI. 

DISTRIBUTION AND CHARACTER.

The outcrops of the Wilcox group extend across Mississippi in a 

northwesterly direction from the eastern border of Lauderdalc 

County to the northern boundary of the State, where the deposits 

cross into Tennessee (PI. X, p. 162) and form the major part of the 

Lagrange formation.

The Wilcox in Mississippi is subdivided into three formations - 

the Grenada formation, the Holly Springs sand, and the Ackerman 

formation in descending order.9

From the Alabama line to the southern border of Webster County,10 

the outcrop maintains a fairly uniform width of about 30 miles, but 

beyond this point northward to the State line its width is about 

twice as great. There are also two detached belts to the west of the 

main area, in northwestern Mississippi.

These boundaries delineate the area within which clays of the 

Wilcox deposits may be sought. However, in many places a mantle 

of loam or even gravel covers the Wilcox beds, so that unless the 

clays outcrop either in the sides of gullies or road embankments the 

deposits have to be located by boring. Some good natural exposures 

are seen in the bluffs that border the Mississippi bottoms in Tallahatchie County.

The Wilcox consists in general of beds of sand, clay, and lignite. 

The sands may be of different colors, cross-bedded in structure, and 

in places contain layers of lignite.

8 Berry, E. W., The lower Eocene floras of southeastern North America: U. S. Geol. 

Survey Prof. Paper 91, 1916. " *

"Lowe, E. N., Mississippi Geol. Survey Bull. 10, p. 23, 1913. Logan, W. N., The 

pottery clays of Mississippi: Mississippi Geol. Survey Bull. 6, 1909.

10 Logan, W. N., op. cit., p. 136.
240 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

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The clays differ in character from

place to place and show considerable

range in their content of silica. They

differ also in their other properties.

The Wilcox beds dip gently westward (fig. 35) and south westward ;

consequently those beds along the

western side of the belt lie higher in

the group than those along the eastern

edge.

CLAYS OF ACKERMAN FORMATION.

The basal formation of the Wilcox

group, the Ackerman,11 consists of

about 300 feet of dark-gray lignitic

and ferruginous clays, lignitej iron

carbonate, and sandstone. Little is

known regarding the quality of the

clay.

CLAYS OF HOLLY SPRINGS SAND.

The middle formation of the Wilcox group, the Holly Springs, is prevailingly sandy. It is about 350 feet

thick and consists chiefly of crossbedded, mostly coarse, micaceous,

white to yellow, red, and purple sands,

hardened in places. It contains lenses,

more or less extensive, of pink and

white, rarely chocolate-colored, generally sandy clays. These clay lenses

seem to be very abundant, however,

for Logan 12 has described many occurrences in Marshall, Benton, Lafayette, Calhoun, Webster, Choctaw,

Winston, Noxubee, and Lauderdale

counties. ,

Some of the lenses have a thickness

of 15 to 18 feet. The clays in general

seem to burn to a cream color, but they

do not fire to a very dense .body on

account of their siliceous character.

11 Berry, E. W., The lower Eocene floras of

southeastern North America : U. S. Geol. Survey

Prof. Paper 91, 1916.

"Logan, W. N., The pottery clays of Mississippi : Mississippi Geol. Survey Bull. 6, 1909.
SEDIMENTARY CLAYS. 241

All show fair to good plasticity, and the content of iron oxide 

ranges from 1.26 up to 3 per cent, or even more. It is probable 

that some of them could be improved by washing.

Up to the present time they have been only utilized locally by 

potteries. Their quantity is unknown. . Their thickness, however, 

in places is considerable, to judge from the following record of the 

city well at Oxford, Miss.: 13

Section of oity well, Oxford, Miss.

Feet.

Clay and sand-___ __________ _________ 90 

Sand___________________________________ 15 

Clay __________________________________ 67 

Soapstone (clay)__ ____ _______________ 78 

Hard sandstone ___________________________ 50

Nothing is known regarding the quality of the clay, but it occurs 

in the Holly Springs sand of the Wilcox group.

The most extensive operation is at Holly Springs, Marshall 

County, where a stoneware factory has been running for some years. 

A number of clay lenses have been noted around this locality,1 * but 

it is doubtful if any of them are of large dimensions. They all pass 

into or are surrounded by sand.

A fairly typical occurrence is seen in a pit about half a mile east' 

of Holly Springs and worked by the Holly Springs Stoneware & 

Firebrick Co. In the north end of this pit a mass of clay about 15 

feet thick and 50 feet long and covered with 3 to 5 feet of loamy 

overburden is exposed. Not more than 30 feet south of this face 

the bank shows 10 feet of cross-bedded sand capped by crusts of 

limonite and over this, in turn, 8 feet of very sandy clay. This section shows how abruptly the character of the material may change 

horizontally. The clay in the west half of the pit contains thin 

sheets of sand and scattered light stains of iron along both the joint 

cracks and the bedding planes.

The clay is used in its crude condition for making common Albanyglazed stoneware, the body of which is steel hard but not vitrified.

The following tests of this clay were made in the laboratory of 

the Bureau of Mines at Columbus, Ohio:

General physical tests of clay from Holly Springs, Miss.

Workability____________Very plastic; works well; smooth. 

Water of plasticity _________________per cent_ 31.25 

Air shrinkage by volume _______ - ________do__ 26. 65 

Air shrinkage, linear, calculated ____________do__ 8. 00 

Modulus of rupture: Raw clay____pounds per square inch__ 381. 9

18 Crider, A. F., and Johnson, L. C., U. S. Geol. Survey Water-Supply Paper 139, p. 65, 

1906.

14 Logan, W. N., The pottery clays of Mississippi: Mississippi Geol. Survey Bull. 6. 

p. 138, 1909.
242 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

Fire tests of clay from Holly Springs, Miss.

Temperature (°C.).

1,190...........................

1,250...........................

1,310...........................

1,370...........................

1,410...........................

Porosity 

(per cent).

17.60

19.21

11.34

.60

.10

Color.

Light buff.... . ....................

Cream color .......................

Light buff.. .......................

Pale buff.. ........................

.....do............................

Volurru) 

shrinkage 

(per cent 

in terms 

of dry clay).

20.40

19.06

22.34

29.20

27.00

Linear 

shrinkage 

(per cent 

in terms of 

dry clay).

7.4

6.8

- 8.2

10.9

9.9

Fused at cone 32. Residue left on 150-mesh sieve, 0.065 per cent. Steel 

hard at 1,190° C. At 1,250° C. the body develops small rusty iron spots.

This clay has good bonding strength. It does not burn white 

enough for the best grades of pottery. Its refractoriness is good, 

but it does not fire to a dense body until the temperature reaches 

1,370° C. Air and fire shrinkage are moderate. It resembles some 

of the refractory bond clays, but for the best results it should be 

mixed with a denser-burning material. Its bonding strength and 

refractoriness are better than those of a sample tested from the same 

formation at Oxford, Miss. It can be used in stoneware and face 

brick or for other uses where this type of clay is needed.

Under the microscope the crude clay shows small grains of quartz 

to be rather common, and abundant hydromica and kaolinite, both 

of which occur in places in bunches. Kutile in minute grains and 

needles is common.

Thin sections of the clay that were fired at the two temperatures 

noted above showed that even at 1,150° C. the hydromica had largely 

disappeared, yielding a dense groundmass, which in part was isotropic and in part carried patches that showed low interference 

colors, scattered through which were grains of quartz. There was 

not much further change in the section when it was fired to 1,300° C.

As the sandy clays of the Holly Springs type dip westward they 

occur only at a considerable depth in Tallahatchie County.

CLAYS OF GRENADA FORMATION.

Distribution and character. The .clays of the Grenada or upper 

formation of the Wilcox group, as already mentioned, form a belt 

that extends northward across Tallahatchie County. The exposures 

lie mainly west of the Illinois Central Railroad.

Natural outcrops are not very abundant, for the clays are capped 

by loam, which conceals them and may even wash down the slopes 

of gullies, thus hiding fresh sections. A good series of natural 

exposures occurs in the bluffs that border the Mississippi bottoms 

about 10 miles west of Enid. In this locality and at several others
SEDIMENTAEY CLAYS. 243

that will be mentioned in a little more detail the clays have been dug 

for the ceramic industry.

These Grenada clays are in general very dense, sticky plastic 

clays, chiefly of refractory character. They are mostly light gray, 

although some beds are dark gray, owing to their content of finely 

divided lignitic material. Scattered thin beds of lignite also occur, 

as well as some thin beds of oolitic limonite. Very little pyrite is 

found in the clay, but in some of the pits a thin film of crystalline 

gypsum lines the joint cracks. As this material is undesirable it is 

usually trimmed off.

The following notes give some information regarding the industry 

in. this region:

Pits of J. T. Bramlett.-^-T\iQ pits of J. T. Bramlett form a series 

of openings in the face of the bluff 10 miles west of Enid. The 

property is said to include 35 acres of clay land.

The most southern of several pits, known as No. 15, shows a maximum of 20 feet of clay, covered by 4 feet of gravelly loam. The 

clay extends at least 20 feet below the bottom of the pit.

The clay is very tough and plastic. It contains scattered light 

stains of limonite and in places small grains of lignite. The joints 

in at least the upper part of the deposit show thin films of gypsum, 

but an effort is made to throw these out in mining. About 6 feet 

above the bottom of the pit occurs a 1-foot layer of oolitic limonite, 

which shows in the north face of the excavation. Just north of this 

pit the clay appears to be quite sandy.

Pit No. 5 (PL XVIII, #) lies about 600 feet north of No. 15. 

This pit opens northward on a west facing slope and shows the following section:

Section in pit No. 5, of J. T. Bramlett, west of Enid, Miss. ^

Feet. 

Loess and gravel-_____________________'____ 10

Whitish sandy clay _ _____________________ 15

Lignitic clay____________________________^_ 2

Clay (bored)_____________________________ 12 

Bottom not reached.

In this pit also the layer of oolitic ore is present in the lower portion 

at about the same level as that in pit No. 15.

The top sandy clay is very plastic and smooth, but under the 

microscope it shows fairly abundant fine grains of quartz. Hydromica is exceedingly abundant, but kaolinite occurs sparingly. 

Rutile and tourmaline grains occur only in small quantity. 

> The following tests of this clay were made in the laboratory of 

the Bureau of Mines at Columbus, Ohio:

77412 22- 18
244 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

General physical tests of clay from Bramlett pit No. 5, Emd, Miss.

Workability_____________________Plastic; works well. 

Water of plasticity________________ per cent 34.01 

Air shrinkage, by volume________________do__ 38. 54 

Air shrinkage, linear, calculated-:____________do__ 15. 00 

Modulus of rupture:

Raw clay____________pounds per square inch__ 525, 8 

Mixture of clay and sand in proportion of 1:1__do__ 289. 2

Fire tests of clay from Bramlett pvt No. 5, Enid, Miss.

Temperature (°C.).

1,130...................................

1,190....................................

1,250...................................

1,310....................................

1,370....................................

Porosity 

(per cent).

10.60

.5

2.09

1.26

.07

Color.

.....do.................................

.....do................................

.....do.................................

Volume 

shrinkage 

(per cent 

in terms of 

dry clay).

22.90

24.7

24.45

28. 45

24.90

Fusion point, cone 30 (1,730° C.). Steel hard at 1,190° C.

This clay shows good strength in the unfired condition and has fair 

bonding stregnth. Its refractoriness is fair. It burns to a dense body 

at 1,190° C., but is not white enough to be used as a ball clay. It is a 

refractory bond clay and should be of value for uses requiring this 

type of clay, such as the manufacture of glass refractories, crucibles, 

abrasives, and stoneware. For all these purposes it would be used in a 

mixture and not alone.

Because of its fine grain and abundance of hydromica the thin sec: 

tion of the clay after firing shows a very dense mass, which seems to 

consist of a very fine felty aggregate.

The lower clay in pit No. 5 is less gritty, but is also exceedingly 

plastic.

Three-quarters of a mile farther north along the bluff is another 

natural exposure, known as pit No. 21, which had not been developed. 

This exposure shows 15 to 18 feet of gray and pink clay above the road 

level and is said to extend 26 feet below it, giving a total thickness of 

over 40 feet at this point. Below the clay there is lignite, and on top 

of it there is a 9-inch layer of lignitic clay. The overburden, which 

appears farther up the hillside, is the usual gravelly loam.

The following tests of this clay were made in the laboratory of the 

Bureau of Mines at Columbus, Ohio:
SEDIMENTARY CLAYS. 245 

General physical tests of clay from Bramlett pit No. 21, Enid, Miss.

Workability_Plastic; smooth ; works well in molding; dries well. 

Water of plasticity______________>___per cent 35. 20 

Air shrinkage, by volume_______________do__ 30.48 

Air shrinkage, linear, calculated_____________do__ 11. 0 

Modulus of rupture:

Raw clay _ _ pounds per square inch 533. 6 

Mixture of clay and sand in proportion of 1:1 do__ 404. 5

Fire tests of clay from Bramlett pit No. 21, Enid, Miss.

Temperature (°C.).

1,190...............:.. .......

1,250.........................

1,310.........................

h370. ............... .........

1,410.........................

Porosity 

(percent).

9 1

2.02

2.37

2.00

14.40

Color.

Buff...............................

Volume 

shrinkage 

(per cent 

in terms 

of dry clay).

99 fin

25.49

26.00

25.20

Linear 

shrinkage 

(per cent 

in terms of 

dry clay).

8

0

9.4

9

C

9.3

Fusion point cone 30 (1,730° C.). Steel hard at 1,900° C.

This clay has good bonding strength and good firing range, but is 

overfired at 1,410° C., or even lower, and though it: may be classed 

as a refractory bond clay it is not of the highest type, and according 

to Bleininger's classification it is not adapted for graphite crucibles. 

It does not burn white enough for ball clay. It is also somewhat less 

refractory than the clay from pit No. 5, described above. It could 

be used for pottery, face brick, terra cotta, or other uses which demand this type of clay.

A clay similar to that in pit 21 outcrops up the creek about onefourth of a mile eastward.

The clay in the main exposure is light gray, dense, and even-textured. It feels smooth and is very plastic, but contains some fine 

grit.

At 1,150° C. the clay is steel hard and has 5.6 per cent absorption. 

At 1,300° C. it shows no absorption and but 0.4 per cent porosity. It is 

steel hard and buff.

A microscopic examination of the raw clay showed some quartz, 

very abundant hydromica, and rather numerous grains of kaolinite. 

Rutile and tourmaline were very scarce.

A thin section of the burned clay showed a very fine-grained, 

felty-looking mass similar to that of the burned clay from pit No. 15.
246 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Property of McLendon Clay Co. The McLendon Clay 'Co. has a 

property on Deese Creek, 3 miles southeast of Crevi, or 6£ miles 

west of Enid. Only some trial shipments have been taken out.

The clay is exposed near the base of a high bluff that borders the 

creek. The bed is 6 to 10 feet thick and is covered by a maximum 

thickness of 50 feet of the gravelly loam overburden.

It is claimed that the clay has been determined by boring to extend 

18 feet below the creek level and that it underlies the low ground 

north of the bluff, but no natural outcrops occur there.

The following tests of samples taken from the foot of the' bluff 

along the creek were furnished by Mr. McLendon:

Tests by Norton Emery Co.: Color of clay, gray. Structure, massive. Hard, tough. Sand, fine grained. Coarse impurities, none. 

Drying properties, good. Plasticity, very good; water of plasticity, 

32.3 per cent. Drying shrinkage, 8.05 per cent; fire shrinkage, 7.48 

per cent; total shrinkage, 15.93 per cent.

The burned clay has dense structure and shows bluestoning. Color 

after burning, brownish buff. Steel hard. The material is rated as 

a good grade of fire clay and is recommended as a bond clay if the 

strength is high enough.

Test by the Bureau of Standards: Linear shrinkage, 6.25 per cent. 

Dries without difficulty. Burns dark buff and vitrifies at cone 13 i 

(1,400° C.). Modulus of rupture, 1,168 pounds to the square inch. 

Fusion point, cone 29 (1,710° C.). The clay is recommended for 

crucibles.

Tests by A. S. Watts: Sample No. 1 fuses at cone 26 (1,650° C.).

Sample No. 2: Air shrinkage, 10 to 10.2 per cent. Fire shrinkage, 

18 per cent at cone 12 (1,370° C.) at which it is vitrified. Suggested 

v as useful for glass pots.

Sample No. 3: Air shrinkage, 7 per cent; total shrinkage, at cone 

2 (1,170° C.), 14 per cent, and at cone 8 (1,290° C.), 15 per cent. 

Below 1,200° C. it burns buff, but at this temperature it is graybrown and remains so to 1,250° C. Gray above 1,250° C. Almost 

completely vitrified at cone 8 (1,290° C.). Recommended as base for 

terra cotta, bricks, or fire brick.

The following analysis was furnished by the Mississippi Agricultural College: . .

Analysis of McLendon Clay Co.'s clay.

Silica (SiO2 )_______ ____________________ 57.28 

Alumina (AL03 )__________________________ 28.54 

Ferric oxide (Fe2 03 )________________________ 2.68 

Lime (CaO)_____________________________ .36 

Moisture _______________________________ . 86 

Organic and volatile matter_________________ 9.40

99.12
SEDIMENTARY CLAYS. 247

Pits of Mitchell Clay Co. The Mitchell Clay Co. has operated several pits in the slope of the bluffs that overlook the bottoms 10 miles 

west of Enid.

Property of Southern Ball Clay Co. The Southern Ball Clay Co. 

owns several deposits of clay in the territory west of Enid and claims 

to have 80 acres of clay land.

Pit No. 1 is 7 miles west of Enid, on Shelton Creek. A pit has 

been dtog on the east side of the creek and on the west base of a low 

wooded ridge. The clay outcrops also on the east side of the ridge.

After the gravelly loam overburden 7. to 8 feet thick was stripped 

off, the pit was carried to a depth of 9 feet in clay, and a boring in 

the bottom of the excavation showed 31 

feet more of clay, at 

which depth lignitic

clay was struck. As 

the creek showed some 

outcrops of clay in its 

channel, which was 

cut to a depth of 6 

feet in its flood, plain, 

a series of bore holes 

was made in the flat 

several hundred yards 

to the south. All of 

these bore holes struck 

clay.

Pit No. 2 of the same company is on Sherman Creek 4 miles south of 

Crevi. At this place clay is exposed in the bluff (fig. 36) in several 

beds of varying character. It is claimed that the lower bed was 

proved to a depth of 35 feet by boring, and the tests of the samples 

obtained in this manner are given in column 2 in the table on page 248. 

If the clay continues under the depression to the north of the bluff, 

this area would be a much better place for an opening, as there would 

be less overburden to remove.

The deposit was not being worked and had not been opened in 

June, 1918.

The following tests represent a series made by E. Lovejoy for the 

Southern Ball Clay Co. on samples supplied by them.

icofeet

FIGURE 36. Section along Shermau Creek, 4 miles 

south of Crevl, Miss., on the property of the Southern 

Ball Clay Co. a, Ferruginous sand; b, whitish sand 

and clay; c, lignitic clay ; &, grayish-white clay.
248 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

General physical'tests of clays from property of Southern Ball Clay Co.

Plasticity, stickiness considered. ............... 

Strength: Length of bar 

flowing from die unsupported (inches). ....

Water required (per 

cent) ..................

Quantity of material 

that passes through 

200 mesh.............. 

Deleterious material .....

Behavior in machine. . . .

Behavior in drying. ......

Shrinkage in drying .....

Scum....................

Efflorescence after firing. 

Color when burned ......

Hardness................

Refractoriness, cone .....

1

Good..........

S),. ............

25.4. ..........

99.89.......... 

Quartz, muscovite mica.

Tears .........

5.3............

Yellow-green . .

31.............

2

Good.......... 

8..............

27.4...........

98.5........... 

Pyrite, quartz, 

or feldspar.

Tears and

laminates.

6.3............

None.......... 

Yellow. .......

3

Good..........

7.6............

31.6...........

98.45.......... 

Some FeS?; 

chiefly 

quartz; some 

black mineral; magnetite. 

Tears.........

6.4............

None. .........

low.

31-32..........'

4

Good..........

33.............

99.31.......... 

Chiefly quartz.

Tears.........

6.5............

None.......... 

Yellow; blue

at cone 10.

5

o49.

33.5.

99.45. 

Mostly 

quartz.

Tears.

6.6.

Bad. 

Cream; blue

at cone 10.

32.

a Suspended.

1, 5. Light-gray clay. 2. Dark-gray clay. 3, 4. Gray clay.

Fire tests of clays from property of Southern Ball Clay Co.

Cone 01 (1.130° C.) .

Cone 2(1, 170° C.)...

Cone 4 (1,210° C.)...

Cone 6 (1,250° C.)...

Cone 8 (1,290° C.)...

Cone 10 (1,330° C.).

Fire 

shrinkage (per 

cent).

6.9

6.9

7.0

7.2

7.3

7.6

I

Absorption

(per 

cent).

3.0

1.4

1.4

1.4

1.4

0.0

Fire 

shrinkage (per 

cent).

6.2

6.5

6.6

6.6

6.9

7.2

2

Absorption

(per 

cent).

3.6 2.9*

3.3

2.2

1.3

0.0

Fire 

shrinkage (per 

cent).

8.2

8.2

8.2

8.3

8.6

9.0

J

Absorption

(per 

cent).

4.9

2.9

2.3

.1.6

.7

.1.3

i

Fire 

shrinkage (per 

cent).

7.2

7.2

7.3

7.4

7.9

8.0

1

Absorption

(per 

cent).

1.7

1.6

3.3

0.0

0.6

0.0

Fire 

shrinkage (per 

cent).

7.7

8.3

8.3

8.7

9.0

9.4

Absorption

(per 

cent).

5.0

2.1

5.1

. 2.5

.3

.3

Samples bear same numbers as in preceding table.

Lovejoy recommends these clays for a wide range of wares, including: Buff face brick, especially No. 5; fireproofing, stoneware, and 

refractory products; as bond clay for high-grade fire brick, bauxite 

bricks, glass pots, and crucibles. He states that they all burn to a 

very dense body; in fact, too dense to be used alone.

Charleston, Tallahatchie Comity. Among the recent developments in this region is one begun by the French Clay Blending Co., 

5-| miles north of Charleston, Miss. The clays from this pit are 

being utilized for glass refractories, crucibles, and enameling.

Future of the clays of the Grenada formation. These clays have 

been known for some time, but their real development is of comparatively recent date. In view of their value as refractory bond 

clays, it is probable that there will be a continued demand for them
SEDIMENTARY CLAYS. 249

as long as the supply lasts. Owing to the poor character of the roads 

in much of this region, deposits should be worked as near the railroad as possible. Clays from the bluffs along the Mississippi bottoms have to be hauled 10 miles to Enid on the Illinois Central Kailroad, although there is a railroad only 4 miles distant across the 

bottoms.

UNDEVELOPED PROPERTIES.

By E. N. LOWE.

The following undeveloped properties have been examined by the 

Mississippi Geological Survey. The tests were made by C. W. Parmelee, of the University of Illinois.

CLAYS OF GBENADA FORMATION.

Tocowa, P.anola County. A small exploratory pit has been opened 

at the residence of Samuel Elmore, 3 miles south of Xocowa, Panola 

County, sec. 15, T. 27 N., R. 2 W. At this pit the clay is light gray 

and is 8 to 12 feet thick. The overburden consists of 12 to 18 feet 

of gravel and sand that might be useful for road building. The clay 

presents no visible impurities, except at the bottom, where it becomes 

sandy and passes below into a bed of fine white sand. The gravelly 

overburden contains concretions of brown iron oxide in considerable 

quantities.

North of the pit the face of the hill is covered with slope wash, 

and the clay is covered. In a ravine 300 yards north of the pit the 

clay overlies a bed of good lignite 5 to 5£ feet thick. The clay is 

here a gray, slightly lignitic joint clay, that has a horizontal stratification. In places on the joint surfaces a white deposit of gypsum 

is noticeable. Otherwise the clay is apparently pure and is darker 

gray than at the pit. It passes above into a bluish-purple clay, which 

is very sandy. The gray clay is very plastic and has a thickness of 

10 to 15 feet. The overlying sandy, purplish clay is 15 to 18 feet 

thick. The overburden here consists of 12 to 15 feet of loose sand and 

silt.

General physical tests of clay from Tocowa, Panola County, Miss.

Kind of material________ -Light-gray, medium- hard, plastic clay.

Working properties_ ____________________Good.

Conduct in flowing through die___On the whole works well but

shows tendency to laminate.

Water of plasticity___ t_________________per cent 33. 2

Plasticity____________________________.-Good.

Shrinkage water, in terms of volume of pure clay_per cent_ 20.2

Pore water, in terms of volume of pure clay________do____ 13. 0

Modulus of rupture (average) :

Raw clay _____________pounds per square inch_ 674 

Mixture of clay and sand in proportion of 1:1 461
250 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Fineness test:

Residue, 20-mesh sieve_____________per cent__ 0.17

Residue, 40-rnesh sieve_______________do__ .00

Residue, 60-mesh sieve______:_________do__ .07

Residue, 80-mesh sieve________________do__ .00

Residue, 120-mesh sieve_______________do__ . 18

Residue, 200-rnesh sieve (white sand and mica)_do__ 1.05

Linear drying shrinkage_________________do__ 8. 9

Drying conduct______________-____________ Good.

Fire tests of clay from Tocowa, Panola County, Miss.

Cone.

05.

03.

2.

5,

9.

12.

14.

15.

30..

Temperature (°C.).

1,050

1,090

1,170

1,230

1,310

1,370

1,410

1,430

1,760

Porosity 

(per cent).

25.6

18.7

19.8

13.9

2.1

6.6

14.5

17.5

Color.

.....do.......................

.....do.......................

.....do.......................

.....do.......................

.....do.......................

Hardness.

.....do......................

.....do......................

.....do......................

.....do......................

.....do......................

.....do......................

Linear 

shrinkage 

(per cent).

1.24

2.51

3.45

3.93

4.79

3.33

4.07

4.79

The following conclusions have been reached in regard to this clay:

Plasticity, good; drying shrinkage, normal; strength of unburned 

clay, high; bonding strength, high; warpage, none; porosities, very 

low at cone 9, slight overburning at cone 12, more marked at cone 14; 

color sufficiently good for a ball clay; fusibility high, but overburning 

at cone 12 bars it from the refractory class.

The clay conforms quite closely to the type of the refractory bond 

clay, which should make it of value wherever a plastic, strong, denseburning clay is required. Its color makes it available for use an 

making pottery.

The nearest railroad is the Batesville Southwestern, 5 miles to the 

west, which connects with the main line of the Illinois Central at 

Batesville.

Charleston, TallaJiatcMe County. There is a promising looking 

clay on the G. I. Otott place, 4-J miles from Charleston. The clay is 

reported to be 15 feet thick and has 6 to 8 feet of overburden.

Carrollton, Carroll County. Clay outcrops on the slope of the

hill 150 yards south of the old Dr. Vassar residence in Carrollton, now

owned by Dr. T. H. Somerville, of Oxford, Miss. No pit has been

, opened on this clay, but the outcrop extends along a hill slope half a

mile south of the Southern "Railway at Carrollton.

The best outcrops of the clay are in an old roadbed and in deep 

washes on the roadside. It is a good firm massive light-gray clay, and 

shows no stratification planes, though, taken as a whole, the outcrop 

exhibits somewhat different characters at different levels. Joint
SEDIMENTAEY CLAYS. 251

planes are well marked; indistinct and fragmentary impressions of 

leaves occur in the clay, more noticeably toward the bottom of the 

section. This clay is remarkably free from impurities that can be 

detected by the eye. In the lower third of the deposit an appreciable 

proportion of fine white sand is intimately mixed with the clay. A 

little stain of iron also occurs here and there.

The deposit is 25 feet thick and is covered with 15 to 25 feet of 

soft sand and loess silt. The sand appears to be suitable for building. 

The clay passes down into a whitish-gray clayey sand. Over an acre 

or more the overburden would not average more than 15 feet. The 

clay outcrops in the hill slopes and stream bluffs for a mile or more, 

east and west and half a mile north and south.

Should the clay need washing, Big Sandy Creek is less than onequarter of a mile away, and the city standpipe, supplied by strong 

artesian wells, is on the hill within 150 yards.of the outcrop. The 

clay could be trammed down the natural incline from the hill to the 

Southern Railway.

This deposit is half a mile south of the railroad station at Carrollton, Carroll County.

General physical tests of clay from Carrollton, Carroll County, Miss.

Kind of material ___ Light gray, medium hard, plastic clay.

Working properties_______ _.. ____________ Good.

Conduct when flowing through die_ Shows tendency to laminate.

Water of plasticity.______ _ ___ per cent 37.9

Plasticity______________________.______ Good.

Shrinkage water, in terras of volume of true clay__per cent 25.0

Pore water, in terms of volume of true clay______do__ 12.9

Modulus of rupture (average):

Raw clay____________pounds per square inch 1,093 

Mixture of clay and sand in proportion of 1:1_do__ 385. 6

Fineness test:

Residue, 20-mesh sieve__________,___per cent 0. 28 

Residue, 40-mesh sieve________________do__ . 00 

Residue, 60-mesh sieve______ _ ____do__ .00

Residue, 80-mesh sieve______ ______do__ .00

Residue, 120-mesh sieve_______________do__ 1.07

Residue, 200-mesh sieve____ ______,_do__ 4. 25

Linear drying shrinkage__________________do__ 11. 2

Drying conduct_______.. __________ Pieces warp badly.

Fire tests of clay from Carrolfton, Carroll County, Miss.

H

05. 1,050 22.8 Light bufl................... Steel hard.................. 0.8

03. 1,090 20.9 .....do....................... .....do...................... 2.0

2. 1,170 19.5 Light chocolate-brown....... .....do...................... 2.4

5. 1,230 18.7 .....do....................... .....do...................... 2.7

9. 1,310 11.4 Lightgray................... .....do...................... 3.9

12. 1,370 10.5 .....do....................... .....do...................... 4.2

28. 1,690 Fused.
252 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The following conclusions have been reached in regard to this clay: 

Plasticity, good; drying shrinkage, high; strength of unburned clay, 

very high; bonding strength, high; fire shrinkage, low; porosity, 

moderate; color too dark for a ball clay. It is to be classed as a bond 

clay for certain types of refractories and other wares, as face brick 

and terra cotta.

CLAYS OF HOLLY SPRINGS SAND.

Hudsoiwille, Marshall County^ Clay occurs in a lens exposed in 

a deep wash near the residence of S. B. Gibbons, in sec. 16, T. 2 S., 

R.-fi W., 5 miles northwest of Hudsonville, Marshall County.

The clay is highly plastic and is light gray but near the surface 

is appreciably mottled with iron stains that give it a pinkish discoloration. Locally very fine white sand forms thin partings in the 

clay one-fourth to one-half an inch thick.

The full'extent of this lens can not be made out, but the clay is 

exposed in the bottom and sides of the ravine beneath an overburden of 8 to 10 feet of variegated sands, which in turn are overlain 

by 6 to 8 feet of brown loamy soil. It is probably not more than 

200 to 250 feet in lateral extent. The owner, Mr. Gibbons, stated 

that he had dug a pit 15 feet deep and found the same quality of 

clay to the bottom. He further stated that a boring was made in 

the bottom of this pit, and the same quality of clay was found to the 

full depth of 60 feet in one place; in another place, a few rods away, 

the drill passed into dry sand beneath the clay at a depth of 40 feet, 

but above the sand the clay was of uniform quality, free from sand 

and other impurities.

General physical tests of clay from property of S. B. Gibbons, thidsonville,

Marshall County, Miss.

Kind of material___ Light-pink plastic clay of medium hardness.

Working properties _____ ________________ Good.

Conduct when flowing through die____ Fair; tends to laminate.

Water of plasticity___________________per cent 32. 5

Plasticity _______ _ ______ ______ Good.

Shrinkage water, in terms of true clay volume__per cent__ 15. 5

Pore water _________________________do__ 17.0

Modulus of rupture (average):

Raw clay_____________pounds per square inch_ 395 

Mixture of clay and sand, In proportion of 1:1_do__ 172

Fineness test: '

Residue, 20-mesh sieve_____________per cent__ 0.0 

Residue, 40-mesh sieve_______________do__ Trace. 

Residue, 60-mesh sieve_____________:_do__ 0.08 

Residue, 80-mesh sieve________:______do__ .07 

Residue; 120-mesh sieve_______________do__ .22 

Residue, 200-mesh sieve_______________do__ . 12 

Linear drying shrinkage _______:_______do__ 7. 97 

Drying conduct ___.____________________ Good.
SEDIMENTARY CLAYS. 253

Fire tests of clay from property of S. B. Gibbons', Hudsonville, Marshall County.

~ Miss.

Cone.

05.

03.

2.

9.

12.

13.

14.

15.

30.

Temperature (°C.).

1,050

1,090

1,110

i 9^n

1,310

1,370

1,390

1,410

1,430

1,730

Porosity 

(per cent).

fil Q

' 30.4

25.0

99 ^

7 9

7.1

2.9

2.8

1.4

Co', or.

.....do.......................

.....do.......................

.....do.......................

.....do.......................

.....do.......................

.....do.......................

 Hardness.

.....do......................

.....do......................

.....do......................

.....do......................

.....do......................

.....do......................

.....do.........-...........:

Linear 

shrinkage 

(per cent).

1 A9

2.89

4.79

6 04

7.58

8.57

9.32

10. 05

8.40

The following conclusions have been reached in regard to this 

clay.: Plasticity, good; drying shrinkage, normal; strength of unburned clay, good; bonding strength, fair; fire shrinkage, normal; 

warpage, none; attains low porosity at cone 9 and is not overfired 

at cone 15, hence shows long heat range; color, sufficiently good to 

serve as a ball clay. It can be used as a bond clay in the manufacture 

of pottery, abrasives, or refractories.

Lamar, Benton County. An outcrop of white clay occurs on the 

old Judge A. M. Clayton place, 2 miles south of Lamar. The clay 

is exposed in a deep ravine washed out of the hill 200 yards south of 

the residence, at a spring. This clay occurs in thin beds interstratified with sandy clay, all light gray to white. A very thin stratum 

of the clay is pure white and entirely free from grit.

The. clay beds are 18 feet thick, but in part are rather sandy. The 

deposit appears to be rather small in area, and is undoubtedly a lens 

60 to TO yards from north to south, and perhaps about the same from 

east to west. Except for a little stain of iron in places and the 

alternating beds of sandy clay, the clay of this deposit appears quite 

pure.

The overburden consists of 6 to 15 feet of sand and loam. The 

deposit is one-fourth of a mile east of the Illinois Central Railroad.

The transverse strength of this clay is 173.6 pounds to the square 

inch.

Oxford, Lafayette County. In the Isom Ravine, a deep ravine 

that faces eastward, thick deposits of clay are exposed a few rods 

north of the high-school building in the town of Oxford.

The deposit is undoubtedly a lens, for the ravine cuts through the 

clay into underlying sands. This clay is very firm, almost a shale, 

and is light pinkish gray to dark gray, the darker color being due 

to lignitic material. It is highly fossiliferous, and some very fine 

specimens of fossil plants have been collected by E. W. Berry from 

this ravine. The clay is highly plastic when weathered. Its visible 

impurities include a little iron oxide, the lignitic matter, and ca 

noticeable sprinkling of scales of mica.
254 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

In the lower half of the ravine the clay is massive or heavy-bedded, 

and becomes distinctly stratified above. This lower phase of the clay 

is 12 feet thick. Above this lower bed, and conformable with it, is 

10 feet of lighter pinkish clay, less fine, which becomes thin-bedded 

and somewhat siliceous. These clay beds are overlain by 15 feet of 

yellowish sands that contain thin pale-pinkish sandy clay laminae, 

above which lies 4 to 12 feet of red sands.

The extent of this deposit has not been made out satisfactorily, 

but an outcrop of similar clay one-quarter of a mile to the south 

is probably an extension of this lens.

General physical tests of clay from Isom Ravine, Oxford, Lafayette County,

Miss.

Kind of material______Light-gray, medium hard, plastic clay. « Working properties________________________ Good. 

Conduct when flowing through a die______________ Good. 

Water of plasticity__________________per cent 64.1 

Plasticity __________^________________.._ Good. 

Shrinkage water, in terms of volume of true clay_per cent_ 19. 7 

Pore water__________________________do__ 44. 4 

Modulus of rupture (average) :

Raw clay____________pounds per square inch__ 149 

Mixture of sand and clay in proportion of 1:1_do__ 62 

Screen test:

Residue, 20-mesh sieve____________. percent_ 10.0 

Residue, 40-mesh sieve________________do__ 5. 2 

Residue, 60-mesh sieve_______________do__ 4. 69 

Residue, 80-mesh sieve_____:__________do__ . 42 

Residue, 120-mesh sieve_..____________do__ 1. 52 

Residue, 200-rnesh sieve_______________do__ 1. 57 

Linear air shrinkage_______________.______do__ 5. 82

Drying conduct.__________________________ Good.

Fire tests of clay from Isom Ravine, Oxford, Lafayette County, Miss:

Cone.

05.

03.

2.

5.

9.

12.

14.

15.

97

Temperature (°C.).

1,050

1,090

1,170

1,230

1,310

1,370

1,410

1,430

1,670

Porosity 

(per cent).

56.0

55.4-

53 9

55.4

32.5

17.0

6.2

.7

Color.

.....do.......................

.....do.......................

.....do.......................

.....do.......................

.....do.......................

.....do.......................

Hardness.

.....do......................

.....do......................

.....do......................

.....do......................

.....do......................

.....do......................

Linear 

shrinkage 

(per cent).

0.72

2.38

2.72

3.50

12.30

16.80

15.0

The following conclusions have been reached in regard to this clay: 

Plasticity, good; drying shrinkage, normal; strength of unburned 

clay, low; bonding strength of unburned clay, very low; color after 

firing, fairly good, white; bluestoned badly above cone 12; warpage, 

none; porosity, high up to cone 12; fire shrinkage, high above cone 9.
SEDIMENTARY CLAYS. 255

The clay may be used where a low-grade refractory clay is suitable, 

but because of its lack of strength it will 'ordinarily be mixed with 

stronger clays. It is slightly stained with iron and hence unsuited 

for white pottery; .could be used in manufacture of face brick.

The deposit is one-quarter of a mile east of the Illinois Central 

Railroad. '

ARKANSAS.

o 

DISTRIBUTION AND CHARACTER.

Branner,15 in his report on Arkansas clays, states:

The Tertiary clays are the most important in the State of Arkansas. As 

already stated, they, with their accompanying sands, marls, and organic deposits, 

underlie a large part of the State east and south of the St. Louis, Iron Mountain 

& Southern Railway south of Arkansas River. North of this and east of the 

Paleozoic hills the sediments are chiefly Quaternary deposits, except Crowleys 

Ridge, the lowest part of which is Tertiary. * * * The sediments laid down 

during Tertiary time vary from place to place in thickness and in character, 

just as any marine sediments of the present time vary. Some of the beds are 

clays and some of them are sands and gravels. * * *

The fire clays of the Crowleys Ridge region are everywhere associated with 

beds of Tertiary lignites, which outcrop in the basins of several of the larger 

streams. Lignites and fire clays occur in the NE. I NE. i sec. 26, T. 4 N., 

R. 4 E.; NW. i SW. i sec. 8, T. 11 N., R. 4 E.; NE. 1 NE. \ sec. 20, T. 10 N., 

R. 4 E.; sec. 30, T. 16 N., R. 5 E.; and in sec..36, T. 19 N., R. 6 E.

Many of these deposits have to be worked by underground methods, 

as the overburden is heavy, but in many places the beds are 3 to 4 

feet thick.

All the analyses given by Branner show a high content of silica.

The Wilcox formation underlies the surface of the whole State 

south and east of the Cretaceous and Midway outcrops and extends 

southward into Louisiana. Little is known, however, regarding the 

value of its clays for making ceramic products. ,

Berry 16 states that they have a total thickness of 400 to 800 feet 

and are predominatingly dark carbonaceous sands and brown laminated, commonly selenitic clays. The latter character does not indicate a high-grade material. However, little has been published 

regarding the quality of the Arkansas clays, except a few chemical 

analyses.

In- Ouachita County, Branner 17 gives the following localities:' 

S. i SE. i sec. 2, T. 12 S., E. 18 W.; NW. J SW. £ sec. 2, T. 12 S., R. 

18 W.; SW. I NW. I sec. 36, T. 11 S., R. 18 W.; NW. i NE. i sec. 12. 

T. 12 S., R. 18 W.

18 Branner, J. C., The clays of Arkansas: U. S. Geol. Survey Bull. 351, p. 39, 1908. 

18 Berry, E. W., The lower Eocene floras of southeastern. North America : U. S. Geol. 

Survey Prof. Paper 91, p. 36, 1916. 

"Branner, J. C., op. cit., p. 138.
256 HIGH-GRADE CLAYS 'OF THE EASTERN UNITED STATES.

Some analyses of the clays of Ouachita County show a low content 

of ferric oxide, but as a rule high silica. If otherwise satisfactory 

the material might be improved by washing.

MINES.

Lester, Ouachita County. The only clay deposits that have attracted any attention seem to be those in the vicinity of Lester. 

Ouachita County.

Owen 18 gives a section at the mine of the Camden Coal & Clay 

Co., in sec. 12, T. 12 S., B, 18 W., as follows:

Section at mine of Camden Coal & Clay Co., Lester, ArJc.

Feet. 

Sand and ferruginous sandstone________________ 20-30 

Ash-colored clay-_________________________ 6-7 

Lignite- ________________:___________ 6 

Pipe clay with segregations of limonite 1 

Light-gray sandy clay, somewhat' ferruginous J' . 

Harris 19 later gives the following section, presumably at the same 

locality or near it:

Section near mine of Camden Coal d Clay Co., Lester, Ark.

Sandy materials, poorly exposed. Feet. 

Light-pink clay_______ _ ____ , 6

White sand______________-_______________ 6

Bluish clay_____ __ _ ___ 8

Lignite _________________________ __ _ ____ 6

The Camden Coal & Clay Co., of Hot Springs, Ark., has opened up 

a mine northwest of Lester, in Ouachita County, in the SE. £ sec. 

15, T. 12 S., E. 18 W. (See fig. 37.) The section at the mine is 

poorly exposed, but a bed of clay, which ranges from 4$ to 8 feet in 

thickness, underlies the lignite. It is dense, plastic, and commonly 

smooth but contains here and there streaks of sand.

A similar clay outcrops 4 miles north of the mine in the bank of 

Ouachita Eiv'er.

About 4£ miles northwest of Lester, the lignite, which is exposed 

in an abandoned tunnel, is overlain by a smooth plastic clay, which 

grades upward into a sandy clay. Below the lignite is a plastic clay 

similar in appearance to that at the Camden Coal & Clay Co.'s mine.

At the Camden Coal & Clay Co.'s mine a tunnel was run east into 

the hill for a distance of 200 feet. At the end of this tunnel a drift 

was run north and south, and every 100 feet on this drift rooms 12

18 Owen, D. D., Second report of a geological reconnaissance of the middle and southern 

counties of Arkansas in 1859 and i860, pp. 128-133, 1860.

19 Harris, G. D., Arkansas Geol. Survey Ann. Kept, for 1892, vol. 2, p. 65, 1894.
SEDIMENTARY CLAYS. 257

feet wide and 6 feet high were opened, all of them in the clay under 

the lignite.

The mine is connected by a branch road with the St. Louis, Iron 

Mountain & Southern Railway about 2 miles to the south.

As the clay in the mine is not sufficiently uniform to be shipped 

crude, the company has constructed a washing plant along its branch 

road about 1-| miles northwest of Lester.

The mine and mill have been idle for some months.

R. is w.

FIGURE 37. Map of region northwest of Lester, Ark., showing location 

of clay mines.

The following physical tests were made by A. V. Bleininger, of the 

Bureau of Standards, on a sample of the clay from the Camden Coal 

& Clay Co.'s mine: 20

General physical tests of clay from vicinity of Lester,' Ark. 

/

Water in terras of dry weight_____________per cent_ 29. 02 

Ratio of pore water to shrinkage water____________ .72 

Apparent specific gravity of dried clay_____________ 1. 89 

Volume shrinkage, in terms of dry volume____per cent_ 32. 32 

Time of slaking______________________minutes_ 128 

Modulus of rupture:

Dried clay________-__pounds per square inch__ 817 

Mixture of clay and sand in proportion of 1:1__do__ 466

20 Bleininger, A. V., and Loomis, G. A., The properties of some American bond clays: 

Am. Ceramic Soc. Trans., vol. 19, p. 601, 1917.
258 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

Fire tests of clay from vicinity of Lester, Ark.

Temperature (° C.).

1,050............................................................................ i, 125. ...........................;...............................................

],150............................................................................

1, 200. ...........................................................................

1,290.......................................:....................................

1, 350. ...........................................................................

1, 400. ...........................................................................

1, 450. ...........................................................:...............

1, 475. ...........................................................................

Porosity 

(per cent).

28.95

26.92

26.82

25.45

25.60

25.05

25.02

23.90

22.55

Volume 

shrinkage 

(per cent).

0.92

2.13

2.18

1.60

1,81

1.94

2.24

2.69

Softens at cone 29 (1,710° C.). Does not overflre at 1,475° C.

This clay is of the Gross Almerode type, and the plasticity and 

bonding power of the sample tested was superior to that clay.

Bleininger classes it as an excellent glass-pot material but not 

adapted for crucibles except in mixture with more dense-burning 

clay.

The following tests of the washed clay were made at the laboratory of the Bureau of Mines at Columbus, Ohio:

General physical tests of washed clay, Lester, Ark.

Workability __ _Very plastic, smooth.

Water of plasticity __.______________per cent 29. 73

Air shrinkage, by volume_______________do__ 26.19

Air shrinkage, linear, calculated __________do-__ 9. 5 

Modulus of rupture:

Raw clay ___ pounds per square inch 1, 068. 6

Mixture of clay and sand in proportion of 1 :l_do__ 405.1

Fire tests of clay from Lester, Ark.

Temperature (°C.).

1.190...........................

1.250..........................".

1,310...........................

1,370...........................

1,410...........................

Porosity 

(percent).

18.70

19. 19

20.45

17.50

13.90

Color.

Light buff. .......................

Volume 

shrinkage 

(per cent 

in terms 

of dry clay).

.3.20

4.52

4.11

2. 90

3.50

Linear 

shrinkage 

(per cent 

m terms 

of dry clay).

1.20

1.80

1.61

1.01

1.33

Fusion point, cone 26 . Stee"! hard, 1,190° C. Small spots of iron develop 

at 1,250° C.

This clay has high bonding strength and low fire shrinkage. It 

does not fire to a very dense body and is not white enough after 

firing for a ball clay. It is classed as a bond clay of rather low 

refractoriness. Comparison with another clay from the same mine 

tested by Bleininger shows that its porosity is lower after firing and 

that its fusion point is several cones lower.
SEDIMENTAEY CLAYS. 259

A microscopic examination of the washed clay showed it to be 

coarse grained. Quartz and hydromica were abundant and kaolinite 

common. Grains of tourmaline and rutile. were sparingly present. 

The crude clay was similar in appearance, the chief difference being 

that it contained a few grains of other less common minerals, such 

as titanite and zircon.

Before the operations ceased, several companies had tried this clay 

in making glass pots, with good results.

There are probably other beds of clay in this district, but their 

qualities are not known and all are not likely to be of high-grade 

character. Exposures are not abundant, and prospecting by drilling 

would be necessary in many localities. Some of the clays are known 

to be gypsiferous.

Benton, Saline County. Berry 21 gives a section near Benton, 

Saline County, Ark., which shows appreciable clay, but nothing is 

known regarding its quality. The section is as follows:

Section near Benton, Saline County, Ark.

Feet.

Heavy gravel _____________________________ 0-8 

Sand and gravel, brick-red_____________________ 0-5 

Gray sandy mottled clay______________:________ 0-6 

Plastic gray to brown heavily bedded clay____________ 2-6 

Gray sand__________ __________________ 4-6

Half a mile to the west a small pottery pit shows a few feet of 

brownish sandy clay which grades upward into grayish and pinkish 

clays.

Half a mile to the north of the pit just mentioned, at the Such place 

on the Pine Bluff road, the following section is exposed: .

Section at Such place near Benton, Saline County, Ark.

Feet. 

Reddish sand___________________________ 6-8

Massive brown plastic clay that contains bits of lignite_____ 6 .

LAQRANGE FORMATION.

CORRELATION AND CHARACTER.

The Wilcox deposits extend northward across western Tennessee 

and Kentucky, but there they are included in the Lagrange formation, 

of which they form the major part. The upper part of the Lagrange, 

however, includes beds of Jackson and possibly of Claiborne age; 

and the Lagrange formation does not include all of the Wilcox group 

as represented in Mississippi, because the Ackerman formation is

* Berry, B. W., The lower Eocene floras of southeastern North America: U. S. Qeol. 

Survey Prof. Paper 91, p. 52, 1916.

77412 22 19
260 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

absent in Tennessee and Kentucky. In fact, most of the Lagrange 

probably corresponds to the Holly Springs sand,22 but in many places 

it differs greatly from the Holly Springs in lithologic characters.

In general, the Lagrange of Tennessee and Kentucky consists of 

interbedded sands, clays, and lignites, but the lignites are less developed than those in the basal Wilcox of Alabama and Mississippi. 

The sections in the clay pits differ from place to place. Moreover, 

owing to the lenticular character of the deposits, careful boring is 

necessary to accurately determine their extent and content of clay.

TENNESSEE. 

DISTRIBUTION AND CHARACTER.

In western Tennessee the Lagrange is the thickest formation present and covers a larger area than any of the others, but it has the 

fewest surface exposures. (See PL XIX, A.)

The best clays occur along its eastern outcrop, which extends from 

the southwestern part of Hardeman County north-northeastward 

through Chester, Madison, Henderson, Carroll, and Henry counties. 

(See PL X, p. 162.) Along this whole line the Lagrange occurs at no 

great depth. Plate XVII (p. 226) shows the location of active pits 

and prospects on this clay in Tennessee.

Nearly everywhere in the foothills the eastern portion of the Lagrange is covered to a slight depth by the terrace gravels (see PL 

XIX, B) , the loess, or the loam; in the river bottoms it is covered by 

alluvial deposits.

The Lagrange consists of interbedded sands, clays, and lignitic 

material. The largest part is sand, generally fine but some of it 

gravelly. The color of the sand is light yellow or cream, but in places 

it contains Streaks of brown and purple. Lignitic material darkens 

the sand here and there.

The clays range from a fine grade of ball clay to common brick clay. 

Some of them are lignitic, and even beds or layers of pure lignite 

occur. The clay deposits are in the form of lenses, whose central 

portion may be purer than the edges. These lenses as a rule cover 

several acres.

Nelson 23 says that in Henry and Carroll counties their longer axes 

trend several degrees west of north, whereas in Madison and Hardeman counties they extend east of north, and that this statement applies 

to workable deposits in both the Kipley and Lagrange formations.

The clay is mined chiefly in Henry and Hardeman counties, but 

there are small pits in Carroll and Madison counties.

22 Berry, E. W., The lower Eocene floras of southeastern North America: U. S. Geol. 

Surrey Prof. Paper 91, p. 37, 1916.

K Nelson, W. A., Clay deposits of west Tennessee: Tennessee Geol. Survey Bull. 5, 

p. 15. 1911.
TT. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XX

1

Lagra'nge, Ten 

J. F. Dale pi

£:'£%££y&

iMMii.

19

Wickliffe, Ky 

merican Clay

§?^5o?

ERSS

_ *

» *

n.. John 

i 

Loess 3-4'

Gravel 6-7'

Sand 

cross-bedded 20

Clay 7 'maximum

Sand . r 

crossbedded 10

Cooley

Co.

Gravelly 

overburden 3V

Lignite 8-2'

Clay 12'+

2

cKenzie, Ten 

son-Porter Cla 

Williams pit

V-r'-f^^BTpi;

^7V:;'S? jvf ;

 JUi'.'Jj.'iT.-i

.x'il^'i^

.Vj-i'r^JJJS;?

spil

sfis^B^

^ESl

-H^C^^r^

S^"^"

13

Hazel, Ky. 

BallS Sagger 

East pit

i. M 

y Co. Johns

/

Overburden 40'

Clay 5' 

Lignitic clay 1

Gray clay 

(chiefly ball)6'8'

Clay Co. J

Gravel iO'-18*

Sand 3-7' 

Sajgerclay 1*6 

Ball clay 5-6'

Lignitic clay 3' 

Sandy, dark.britlle 

clay 

thickness unknown

3

cKenzie, Tern 

on-Porter Cla 

Oalton pit

-i-^^JgL'TifS;®^

Pf^d^d^il

1. M 

yCo.

(

Light orangecolored sand, 15*

Yellowish-while 

sand II'

Pink streaked 

sand 4/21 

Local hardpan 3" 

Sand, white clay 

breccia 4'-

White clay 12'

Cooley 

White sand

15

'ryorsburg, Ky. 

ayfield Clay Co.

H

RP^=^=5

-^-^~-^~-=~-

^rP^Hf^:

Sandy loamy 

clay 6'

Sandy beds 4' 

Gravel 3-5' 

Sagger clay 4*

Ball clay 9'

Wad clay 3jfe'

Sand, 

thickness unknown

^4

cKenzie, Tenr 

5 miles north 

Sparks pit

 % rir-T^-^r

^^^^

12

Hazel, Ky. 

Ball & Sagger 

West pit

WM-m'M.

§§3®@tS 

5'?«p&s2Ssivi.v

££iiili£

&3§*?§$jWi

JgiSaJfi^SSSS aSSfe&jfej.7*v;a

-j-iy.sA'y.v"^

SliiHiE

h 

ScatesOverburden 5'

Stoneware, ball, 

and saj^er clays

Dark lignitic clay 

thickness unknow

Clay Co.

Loam 8' 

Pi 

Dixie

Gravel 

cross-bedded 30'

Wad clay 4'

Ball cky, $ray 

and pink 9'

Sandy wad 3'+

5

lenry, Tenn 

Reynolds C

gSfigi. J^=E^»

o^dnd1::

5^pE>Ep

i^iSpE^ -^~-^~ =~-^~-

i 

11

jryear, Ten 

Brick &Ti

^O^^-E^E;

^-L-=~I_r^-^~=

3&±^j^&

~Ta^&r^ff£

 z^-^rC^^

SSB^

4r 

. 

:iay Co. r

Sandy 

yellow clay 8 

Concretionary 

r-ironstone , ... 1 broken band 4 

While and orange 

banded sand sfz

Grayishwhile clay 14

Clay 3'

H

n.

e Co. 

Gravel l'-6*

Nal light clay 8-10'

No.2 brown cky 12'

No.3ttre'cky5'

No.4 

refractory cky 6'

NaSballckyS'

Sand, 

thickness unknown

6

niles north 

Paris, Tenn 

H. C. Spink

:#S':;';'Jriv:v'i' 

 S-SSs&.'Svisj

3f J-^ZVU-£3-

ygff7///ff&

ifffffJlUfJ/S/Sl.

Vffltffltf*

16

ckory Grove, 

Old Hickory 

Clay & Talc <

^~ ^~-^~-^-=-~

E£^E>5> :

g>v=52^

S1^^^

^f1^1^^?

of

.

s 3 miles

Orange-red sands 

with siliceous 

gravels, ironstone 

concretions,and 

clay pellets 1Z 

Ferruginous 

*~sandstone(hardpsn) 2" 

White sagger clay 

somewhat sandy 6"

Brown sagger clay 4' 

/Lignite 1/2' 

'Gray-blue and pale-' 

 "brown clay 2' , 

 Lignitic stratum I 

Gray-blue and , 

. pale -brown clay 3 

lignite \'/2.' 

Dark-brown to 

blackish-green clay 2 

Pale yellow-brown clay 4' 

White sand , . 

thickness unknow

Ky.

:o

V Mane

Loam 6' 

Gravel and sand 5'

No.lballcky3' 

Wad cky 9'

Sagger clay 12'

7 

north of Pan'

mm±m£

-^-^r;.-..^=^;^

-5'

n

10

kmitlock, Tenn 

le Clay Minin 

Monroe pit

 ^-^-^.

*:?>f{#$?.f-i'.$°.

?X*vA?-^'?.v*

.fi*.S'?S^-tfeS^v

!'i'.v!'-'.-''rt\ ^ 'v'.V'i'-:

^^^5-

l 

;, Tenn. Mane

Pale-brown ' ' _ 

case-hardened Jg, 

sand 7' 3 

Siliceous tS. 

gravel l' Q 

Orange-brown ^ 

argillaceous' 3 

> sand 5' g. 

Concretionary §' 

ironstone 1' j

White sandy § 

cky and o 

cross-bedded ^ 

sand 20" JT

ET <

gCo.

Sand, grades into 

yelbw cky 8'

Sand, 

angukr chert, 

etc. 6'

\fariegated y 

sand 5' , , La 

Yellow sand 1 "2

Dark-bluish 

clay 10V

Light-^ray 

clay y/z

6

Whitlock, Tenr 

jle Clay Minin

-rUF EIz-CEr^

^r=^^^3r:

vS;^::::;A:::;;l!i

|E^EpE^

3 5^S^G

^^^§

sO1^^^-

^^=^^

17

Vickliffe, K 

Clede-Chr 

Clay Co.

Efiz^Wi;

j^IF.fr'.Z^;

 V 

Mand 

gCo.

Sandy reworked 

yellow clays 12'

Wavy white 

and orangecolored sandy 

beds 6' J

Re^ukr banded 

orange and , 

white sand 30

Lignite kyer 

No.5 ball clay 4f-5' 

No.4 dark 

(ball?)cky 3'

No. I ball clay 5'-6' 

No.7ballcky5'

No.4 ball clay 4' 

A2 clay 3'-4'

Sagger, clay 8'-10' 

yisty v 

La

Sandy cky 4' 

Bkck clay 8 -10"

Sandy light-f 

Jray cky 10*

9

Mitlock", Tenn 

te Clay Minin 

Cole pit

~r^^^^-i

WiiJi.

^p^s

&j^M

E=B^

^ Z2-£2r^I

-Z>-EZr-^r

18 

Vickliffe, K 

Clede-Chr 

Clay Co.

W^^

ll^^^

f

z Co. Kent 

&l

Overburden 

30 maximum

Special selected 

light clay 15'

Special selected 

black cky 9*

yisty

Yellow-stained clay i 

White -sand 6" 

Sandy clay 5'

Black clay 3 P+

14

'ryorsburg, Kj 

ucky Constru 

mprovement

 ':>:.V'-ji':':V?!v/-:j

S^i^og??^:^

^^^^^S£

^o^^

^^^®

^^^s

^^^^

li^Ei^B^B

^^^^ 

'^5^^^- 

^^&%^f 

b=S®£^

'

f. 

ction 

Co.

Sandy cky S' 

Gravel 3fe'

Orange-colored sand4'/2'

Loose conglomerate 2' 

Orange -colored sand I'/a' 

Interbedded sand and clay lenses t

Variegated sand 5'/z 

-flardpan ironstone 6" 

Tou^h brown cky 6"

Lignite and lignitic cky 

occurs locally 0'-!2fe

Sagger cbyNo. 1,3^'

Ball cky Mo.2,5fe' 

Dark clay 1' 

No.3.ballclay4f/2r

Cky.colored some by lignite 15k' 

^Hi^hly lignilio clay 6" 

Ball cky Mo.V'.chocolatecolo?-3d with li|ht mottlin^s

No. 5 ball cky 4/2-5' 

Nos. 6 and 7 fire clay 10'

COLUMNAR SECTIONS OF LAGRANGE FORMATIQN OF WESTERN TENNESSEE AND KENTUCKY. 77412 22. (Face p. 260.)
SEDIMENTARY CLAYS. 261

The upper part of the Lagrange formation carries beds of dark 

lignitic clays, which are penetrated in wells in this region. At Memphis there is 200 feet of blue clay, but it is not known whether the bed 

is continuous.

One of the best sections of the Wilcox portion of the Lagrange 

formation is exposed at the town of La Grange, in southeastern 

Fayette County, where the clay lenses can be seen completely surrounded by sand (PI. XXI, B}.

The amount of overburden covering the clays differs in different 

localities, and in some places as much as 40 feet is stripped off to 

recover 12 or 15 feet of ball clay. Unless the deposit is extensive 

and the covering can be cheaply removed this overburden may prevent successful mining.

LOCALITIES.

GENERAL FEATURES OF THE MINES.

A number of the working pits were visited by the writer in the 

month of June, 1918, in company with W. A. Nelson, State geologist 

of Tennessee, and the following brief notes were then collected. Some 

of these pits were in operation in 1911 when the State Geological 

Survey issued a report on the clays of western Tennessee,24 but others 

have been opened since.

These descriptions and the sections given in Plate XX show that 

the grades of clay mined include ball, sagger, and wad clays, but 

these terms do not really indicate the variety of uses to which they 

are put.

The deposits are all lenticular and are covered by 3 to 40 feet of 

overburden in#the pits that are worked. Much of this overburden 

is cherty gravel. ('See PI. XIX, B.}

Few deposits yield only one kind of clay; indeed, three or four different grades are commonly obtained from the same lens.

Most of the clays are massively bedded. The individual beds are 

commonly differentiated by color, although they may differ in other 

physical properties such as texture, plasticity, shrinkage, refractoriness, and color-burning qualities.

The thickness of the several grades or beds in a pit may also differ 

from place to place, the difference being sometimes marked even 

within a distance of 50 or 100 feet.

The clay is worked by open pits and dug by hand. Steam shovels 

or'other mechanical diggers as a rule are used only to remove the 

overburden. This overburden consists in most places of. terrace

84 Nelson, W. A., Clay deposits of west Tennessee: Tennessee Geol. Survey Bull. 5, 

1911. Additional descriptions, Including those of many unworked deposits, are given in 

a later report by R. A. Schraeder in The resources of Tennessee, vol. 9, No. 2, 1919.
262 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

gravels or loam but in few places of sand of the Lagrange formation and is commonly thrown on the dump.

The different grades of clay in the deposit are separated in digging 

and either loaded diiectly on the cars, or, at a few pits, placed in 

storage bins.

Two companies have constructed narrow-gage branch roads to the 

railway line, but generally the clay is hauled by teams.

As is but natural, most of the deposits which have been opened 

are fairly close to the railroad, but as these are worked out others 

more remote from rail lines will be developed. Indeed, some of those 

now being worked are 3 to 4 miles from the railway.

Several of the companies operating in Tennessee have been prospecting the territory quite actively so as to be assured of a reserve 

supply, and the results indicate that there is much good clay still in 

the ground.

The map (PI. XVII, p. 226) shows both the worked pits and also 

the outcrops or prospects noted by the Tennessee Geological Survey 

and visited in part by the writer.

The localities are here described in general from south to north.

LA GRANGE, FAYETTE COUNTY.

J. F. Dale sand pit. The pit of J. F. Dale, which is 1 mile 

south of La Grange, is worked only for sand but is interesting because 

its section shows the typical occurrence of the clay in lenses surrounded by sand.

In this excavation, which covers 3 to 4 acres, the lens of clay shown 

in Plate XXI, Z?, has a maximum thickness of 7 feet and tapers out 

to a knife edge in both directions. Its length as exposed is about 

100 feet, A second lens occurs at a lower level on the south side of

the pit. The upper surface of the clay lens is sharply defined and 

has evidently been eroded somewhat, for the basal part of the overlying sand contains clay pellets, the largest of which are 3 inches in 

diameter. The base is more irregular than the top and is marked by 

a thin streak of limonite.

This pit shows on a small scale the relationships that exist in most 

of the clay deposits. The chief difference is that the overburden at 

most of the clay pits consists of gravel and loam, and not of sand as 

at this pit. A columnar section at this pit is shown in Plate XX, 

No. 1. A microscopic examination was made of the clay forming 

the lens mentioned above, of the sandy clay at the bottom of the 

lens, and of the sand underlying the clay lens. The results of these 

determinations are tabulated below.
(J. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXI

A. McNANEE CLAY PIT, LAGRANGE, TENN.

S. 1. F. DALE SAND PIT, LAGRANGE, TENN.
U. S. GEOLOGICAL SURVEY 

SAGGER CLAY PIT OF SCATES-REYNOLDS CLAY CO., SOUT
SEDIMENTARY CLAYS. 263 

Minerals in clay and sand of Dale pit, La Orange, Tenn.

Rutile..................

1

.....do..................

2

Alittle. ................

.....do..................

grains.

.....do..................

Very abundant.

Do.

Do.

1. Clay forming main part of lens.

2. Sandy clay at bottom of lens.

3. Sand underlying clay lens.

McNanee pit. A shallow pit one-fourth of a mile west of La 

Grange, from which clay was formerly dug by J. Davenport,25 is 

known as the McNanee pit. (See PI. XXI, A.)

It is somewhat difficult to give a section representative of the entire 

pit, as the materials differ widely in different parts of the excavation, 

but the general sequence is as follows:

Section in McNanee pit, La Grange, Tenn.

Feet.

Overburden, consisting of loam, underlain by gravel __ 8-25 

White and pinkish clay_____________________ 6- 8 

Layer of limonite_______________________ _ 4 

Sand________________________________ 1- 3 

Whitish clay.

The clay is coarse textured and lies in lenses. It bears laminae of 

sand, and in this respect it resembles that worked at Holly Springs, 

Miss. (p. 241), from which it differs in that the sand contains more 

mica.

On the whole the deposit is similar to the deposits found in the 

Holly Springs sand of the Wilcox group in Mississippi.

Very little clay is being dug at this pit, and that which is excavated 

has to be hauled but .a short distance to the railroad. The use is not 

known, but it has been shipped to potteries.

The mineral composition of this clay is somewhat similar to that 

from the Dale pit, described above. It is medium grained and shows 

abundant quartz. Hydromica and kaolinite are also abundant, and 

the hydromica is much more abundant than it is in the clay from 

the Dale pit. Rutile is present in numerous small grains, and there 

are a fervv grains of zircon and chlorite. The clay therefore resembles 

that from Holly Springs in its mineral composition.

PINSON, MADISON COUNTY.

Light-colored sandy clays of Wilcox age outcrop in this county, 

but very little use has been made of them except at Pinson, where

08 Nelson, W. A., Clay deposits of west Tennessee: Tennessee Geol. Survey Bull. 5, 

p. 61, 1911.
264 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

pottery was manufactured for some years. The clays in this county 

probably resemble those from La Grange already described.

M'KENZIE, CARROLL COUNTY.

Johnson-Porter Clay Co. In 1911 the Johnson-Porter Clay Co. 

was operating two pits about three-quarters of a mile northeast of 

Henry, but these have been abandoned, and in the summer of 1918 

the company was operating two others, 4^ miles northeast of McKenzie. They were connected by a narrow-gage road with the Nashville, Chattanooga & St. Louis Railway.

The two pits which are known, respectively, as the Williams (PI. 

XXIV, B) and the Dalton, are about 500 feet apart.

The first pit covers several acres and shows about 40 feet of overburden under which there is from 5 to 12 feet of clay. (See PI. XX, 

No. 2.) The three grades of ball clay which are dug, are known as 

No. 9, a dark-gray clay, chiefly from the lower part of the bed; No. 

10, a light grayish-white clay; and No. 11, a pink and brown clay.

Clays Nos. 10 and 11 are more or less mixed in the deposit and 

have to be separated after digging. The waste is sold for saggers.

Clay No. 10 is a very plastic clay of fine grain, which, under the 

microscope, shows a few grains of quartz, abundant hydromica, and a 

little less kaolinite. Aside from these minerals a little rutile and 

tourmaline was noticed.

Clay No. 11 is also very plastic and fine grained and shows practically the same mineral composition, with the exception of tourmaline, 

which occurs in amounts so small that it may or may not be present in a sample.

This clay burns cream-white at 1,150° C. and is steel hard. At this 

temperature it has 10.1 per cent absorption and 25.3 per cent porosity;

at 1,300° C. it .has but 5.4 per cent absorption and 14.2 per cent

porosity.

 The clay is dug with pick and shovel, but the overburden is removed by steam shovel.

The clays from this pit are used in pottery, electrical porcelain, 

and grass pots. Some of clay No. 10 is used, for steel enamels.

The Dalton pit was opened in 1918. It showed about 36 feet of 

overburden over about 12 feet of clay. (See PL XX, No. 3.) The 

upper part of the clay is open textured and sandy and ranges from 

a thin film to 2 feet in thickness. The lower part is a ball clay similar to clay No. 10. It is claimed that clay No. 10 can be used as a 

substitute for the Vallendar clay if washed. White sand underlies 

the clay. Plate XXIII, A, shows the contact of the clay and the 

overlying sand, which contains lumps of the clay that were evidently 

loosened by erosion.

The following tests of the Johnson-Porter ball clays Nos. 9 and 

11 were supplied by the Tennessee Geological Survey:
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXIII

A. NEAR VIEW OF FACE IN DALTON PIT OF JOHNSON-PORTER CLAY CO., 

NEAR McKENZIE, TENN.

B. VIEW IN PIT OF COOLEY BALL & SAGGER CLAY CO., IN HENRY COUNTY, 

TENN., 8 MILES NORTHWEST OF PURYEAR.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXIV

A. PIT OF MANDLE CLAY MINING CO., WHITLOCK, TENN.

.' .; «* >>.- '" * ',.'* ; '

B. WILLIAMS PIT OF JOHNSON-PORTER CLAY CO., NEAR McKENZIE, TENN.
SEDIMENTARY CLAYS. 265

General physical tests of Tennessee ball clay No. 9.

Working property____________:_________ Very sticky. 

Water of plasticity_________ _ _ per cent 35. 5 

Modulus of rupture:

Unburned clay_________pounds per square inch 240

Mixture of clay and sand in proportion of 1:1__do__ 138. 9 

Slaking test________________-______minutes 12 

Fineness test:

Residue, 20-mesh sieve___________________ None.

Residue, 40-mesh sieve___________________ None.

Residue, 60-mesh sieve____________________ None.

Residue, 80-mesh sieve____________________ None.

Residue, 120-mesh sieve (white sand)____per cent 0.08

Residue, 200-mesh sieve (white sand)_____^__do__ .67 

Drying shrinkage, linear__________________do__ 8.82 

Drying conduct___________________________ Poor.

Fire tests of Tennessee ball clay No. 9.

Total

Color. Hardness. shrinkage 

(percent).

Cone2(1,170° 0.)...................... Dark tan.......... Steelihard......... 6.0 0.78

Cone5 (1,230° C.)...................... .................... .....do............ 16.2

Cone 9 (1,310° C.)...................... Light brown...... .....do............ 13.3 1.8

Cone 12 (1,370° C.)..................... .....do............ .....do............ 11.7 6.2

Conel3( 1,390°C.)..................... .....do............ .....do............ 13.0 15.0

Fusion test: Deformed at cones 32-33 (1,770°-1,790° C.).

The color of the clay when fired is dark, and hence it is not ranked 

with the best ball clays. It is strong and refractory and will serve 

for purposes where a plastic refractory clay is required as a bond 

clay. It may be used in the manufacture of chemical and other stoneware, face brick, and saggers, and possibly in the manufacture of 

abrasives. The clay will have to be burned carefully because of the 

apparent tendency to overburn at cone 13 (1,390° C.).

General pJiysical tests of Tennessee l)all clay No, 11.

Working property___________________ Good; sticky. 

Water of plasticity__________________per cent 42. 5 

Modulus of rupture:

Raw clay__..______.._pounds per square inch 95. 3

Mixture of clay and sand in proportion of 1:1__do__ 118. 6 

Slaking test _ _ _____________minutes 9 

Fineness test:

Residue, 20-mesh sieve____________________ None.

Residue, 40:rnesh sieve____________________ None.

Residue, 60-mesh sieve___________________ None.

Residue, 80-mesh sieve ____________________ None.

Residue, 120-mesh sieve ___________________ Trace.

Residue, 150-mesh sieve __________________ Trace.

Residue, 200-mesh sieve-__________________ Trace. 

Drying shrinkage, linear______________per cent 5. 75
266 HIGH-GEADE CLAYS OF THE EASTERN UNITED STATES. 

Fire tests of Tennessee ball clay No. 11.

Cone 2 (1,170° C.)...... ................

Cone 5 (1,230° C.) ......................

Cone 9 (1,310° C.) ...................... 

Cone 12 (1,370° C.)..... ................

Cone 13 (1,390° C.) .....................

Color.

White............

.....do............

Gray-white. ......

Hardness.

.....do............

.....do............ 

.....do......:.....

.....do............

Total 

shrinkage 

(per cent).

21.5

16.3

17.2 

17.8

17.5

Porosity 

(per cent)

21.15

19.6

17. 7 

2.2

3.4

Fusion test: Deformed at cones 32-33 (1,770°-1,7900 C.).

The strength of this clay appears to be rather low. The color is 

very good and it is fairly well vitrified at cone 9 (1,310° C.). It is 

fairly representative of the ball-clay type and will find use as a ball 

clay. It will also be useful in the manufacture of sanitary ware, 

chemical and other stoneware, face brick, terra cotta, and saggers. 

Its rather high fusion point is likely to make it of service in the 

manufacture of refractories, where a plastic clay of good strength is 

desired.

C. S. Sparks pit. A small pit, known as the C. S. Sparks pit, 

lies 6 miles north of McKenzie on the east side of the road to 

Henry. (See PI. XX, No. 4.) It has been opened in a slope, so 

that the overburden increases to the west.

About 2 acres of clay have been proved by boring, and the lens 

may not be very extensive. The sandy overburden on the property 

ranges from 1 to 15 feet.

Although the clay in the face is somewhat uniform in appearance 

it nevertheless differs a little in its character. The clay from the 

main part of the bed is sold as sagger clay, whereas that from the 

lower part is a low-grade ball clay.

The ball clay is medium to fine grained, gray, and of uniform 

texture. It contains some fine grit or grains of quartz. The microscopic examination shows that hydromica and kaolinite are equally 

abundant. Tiny grains of rutile are also rather numerous. Tourmaline and epidote are present in very small amounts. The clay 

burns to a cream color.

Some of the output is sent to the Sparks stoneware factory at 

McKenzie.

The pit is operated by Chrisman & Reynolds, of Henry, and the 

clay has to be hauled there for shipment.

The following tests of the Sparks clay were supplied by the Tennessee Geological Survey:
SEDIMENTARY CLAYS. 267

General physical tests of clay from the Sparks pit, near McKenzie, Tenn.

Working property_______________ __ Good. 

Water of plasticity___________ ___ per cent 31.8 

Modulus of rupture:

Raw clay____________pounds per square inch_ 101. 2

Mixture of clay and sand in proportion of 1:1__do__ 108 

Slaking test______________________minutes 5 

Fineness tests:

Residue, 40-mesh sieve ___________________ None.

Residue, 60-mesh sieve ________________. -- None.

Residue, 80-mesh sieve __________________ None.

Residue, 120-mesh sieve (white sand)_________ Trace.

Residue, 150-mesh sieve (white sand) Trace.

Residue, 200-mesh sieve (white sand)_____ Trace. 

Drying shrinkage, linear ________ per cent 5. 2

General physical tests of clay from the Sparks pit, near McKenzie, Tenn.

Color. Hardness. shKfe

Cone 2 (1,170° C.)...................... Cream............' Steel hard......... 11.2 2.1

Cone 5 (1,230° 0).......*............... Tan............... .....do............ .12.1 2.1

Cone9 (1,310°C.)-..................... Gray.............. .....do............ 14.3 1.6

Cone 12 (1.370° C.)..................... .....do............ .....do............ 14.0 1.5

Cone 13 (Ii3900 C.)...................... .................... .....do............ 11.9 4.5

Fusion test: Deformed at cone 28 (1,690° C.).

The color of the burned sample is not quite satisfactory, possibly 

because of reducing conditions in the kiln, and it seems doubtful that 

the clay will be available in the manufacture of white wares because 

of its evidently high content of iron. The strength of the clay is 

fair. It fuses at too low a temperature to permit its use in the manufacture of refractories which are to withstand high temperatures. It 

is likely that this clay will be more serviceable in the manufacture of 

chemical and other stoneware, face brick, and terra cotta.

HENRY, HENBY COUNTY.

Several pits are in operation at this locality as shown on the map 

(PI. XVII, p. 226), but the largest is that known as the Breedlove pit, 

1£ miles south of Henry, which is operated by the Scates-Eeynolds 

Clay Co. (PI. XXII).

This opening is a large shallow pit about 400 feet in diameter, the 

section of which is shown in Plate XX (No. 5).

The clay lens, according to Nelson,26 is about 500 by 1,200 feet in 

area, and its longer axis extends N. 30° W.

M Nelson, W. A., Clay deposits of west Tennessee: Tennessee Geol. Survey Bull. 6, 

p. 87, 1911.
268 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Some of the clay is fine grained in places, but most of it shows thin 

laminae of sand.

The overburden, which is in part sand of Wilcox age and in part 

of later age, is not utilized.

The clay possesses good plasticity but is not so fat as the ball clays 

and contains much fine grit.

Under the microscope it appears to be of medium grain. Quartz 

and hydromica are abundant, and kaolinite is common. Tiny grains 

of rutile are numerous, and a few crystals of tourmaline and zircon 

were noted.

The clay when fired to 1,300° C. is light buff and steel hard. Its 

absorption is 4.9 per cent and its porosity 11.9 per cent. A section 

of the clay burned to this temperature showed numerous grains of 

quartz, but no traces of hydromica remained, the groundmass being 

in part isotropic and in part composed of grains that showed low 

interference colors.

The following tests of this clay were supplied by the Tennessee 

Geological Survey:

Tests of Scates-Reynolds sagger clay from Henry, Tenn.

Working property-__________________________Good. 

Water of plasticity__________________per cent 27. 2 

Modulus of rupture:

Unburned clay_________pounds per square inch_ 69.3

Mixture of clay and sand in proportion of 1:1__do__ 112 

Slaking time ______________________minutes 8 

Fineness test:

Residue, 20-mesh sieve___________________None.

Residue, 40-mesh' sieve____________________None.

Residue, 60-mesh sieve__:_________________None.

Residue, 80-mesh sieve________________None.

Residue, 120-mesh sieve ___ _ _ ____________None.

Residue, 150-mesh sieve________________: __None.

Residue, 200-mesh sieve___________________None.

Drying shrinkage, linear __'________per cent 5.6

F$re tests of Scates-Reynolds sagger clay from Henry, Tenn.

Total

Color. Hardness. shrinkage 

(percent).

Cone 2 (1,170° C.)...................... Light cream...... Steel hard......... ............ 24.8

Cone5 (1,230° C.)...................... .....do............ .....do............ 10.3 25.3

Cone9(l,310°C.)...................... .....do............ .....do............ 13.2 8.8

Cone 12 (1,370° C.)..................... Light gray............................ 10.0 5.5

!

Fusion test: Deforms at cone 28 (1,690° C.).

The clay has good color when burned, and shows fair vitrification 

at cone 9 (1,310° C.). The strength of the unburned clay is low.
SEDIMENTARY CLAYS. 269

\

and it is not sufficiently refractory to be regarded as a plastic refractory bond clay. It is likely to be of service in the manufacture 

of sanitary ware, chemical stoneware, stoneware, face brick, and 

saggers.

All the clay dug here is sold for saggers.

The clay has to be hauled 1-J miles to Henry station on the Louisville & Nashville Railroad.

The section shown in Plate XX (No. 6) is exposed at the Hilltop 

mine or the McClure pit of the H. C. Spinks Clay Co. The section 

shown in Plate XX (No. 7) is exposed at a point 3 miles north of 

Paris, Tenn., and is interesting as showing the occurrence of the 

Lagrange formation at a point where there are no thick beds of clay 

in it.

WHITLOCK, HENRY COUNTY.

Pits of Mandle Clay Mining Co. A number of pits are clustered 

around Whitlock, but the largest are those operated by the Mandle 

Clay Mining Co., of St. Louis, Mo.

The principal pit, No. 4, is 4£ miles northwest of Whitlock, on the 

Nashville, Chattanooga & St. Louis Railway, and one-half mile 

northeast of the Spring Hill road. It covers about 20 acres and is 

connected with the main line by a narrow-gage steam road.

A long north-south face (PI. XXIV, J.), in which the clay thins 

out in both directions, is exposed in the pit.

At the north end of the pit there is an east-west face about 350 

feet long, where clay was being dug in 1918.

As shown in the section (PI. XX, No. 8) the overburden has a 

maximum thickness of about 50 feet. A number of different grades 

of clay occur, the thickness and types of which are given in the section 

as well as the special letter or mark by which each is designated.

The following notes indicate in a little more detail the character 

of some of the beds.

Tennessee ball clay No. 5: Utilized in manufacture of white ware, 

electrical porcelain, and glass pots.

Tennessee ball clay No. 4, dark: This clay is used in saggers, but 

the better selected portions of it are sold to the glass-pot trade.

Tennessee ball clay No. 1, known as S. G. P.: This layer is absent, 

in the central part of the deposit. It is used in making floor and wall 

tile, white ware, and electrical porcelain.

Tennessee ball clay No. 7, known as W. W. C.: This clay has 

similar uses to No. 1 but is said to burn a little denser.

Tennessee ball clay A2: Selected material of this type is used for 

stilson pins and other wares, and some of it is used in the bond of 

abrasive wheels.
270 HIGH-GRADE CLAYS OF THE EASTERN" UNITED STATES.

Sagger clay: This clay is siliceous, short, and hard clay. The bed 

ranges in thickness from 6 to 20 feet in different parts of the deposit, 

but the entire thickness is hot invariably used for saggers. The 

greatest thickness is found in the south end of the pit.

The mineral composition of these grades of clay is given in the 

following table:

Mineral composition of Handle clays from pit No. 4, near Whitlock, Tenn.

Texture..........

Kaolinite. ........

Rutile............

No. 1 S. G. P.

coagulated.

ous, very 

minute needles.

crystals.

No. 5 ball clay.

Very little.....

stained.

No. 7 ball clay.

Very little.....

Common.......

No. 4 white ball 

clay.

grained. 

Very little.....

coagulated.

grains.

crystals.

No. 4 dark ball 

clay.

Very fin e

grained. 

Very little.

Abundant,

coagulated, 

very fine. 

Common.

All these samples run low in quartz and high in hydromica and 

carry kaolinite in lesser amounts. Kutile is abundant only in No. 1.

The Cole pit is about 2 miles north of Whitlock and three-fourths 

of a mile west of the Nashville, Chattanooga & St. Louis Railway. 

It covers about 15 acres, and additional ground is leased but undeveloped.

This pit supplies but two grades of clay (PI. XX, No. 9), known 

respectively as light and black selected, tests of which are given 

on page 271.

The clays from this pit are utilized in making glass pots and 

electrical porcelain, but some of the material is sold as wad clay.

An old pit, known as the Scott or Monroe pit, which was also 

worked formerly by the Mandle-Sant Clay Co. is 2 miles north of 

Whitlock, on the west side of the Nashville, Chattanooga & St. Louis 

Railway. The pit covered between 2 and 3 acres. The overburden 

was 12 to 20 feet thick and the sides of the excavation show as much 

as 20 feet of clay in places.

The new pit, which is not very large, is 4£ miles north of Whitlock 

and 1 mile west of the Nashville, Chattanooga & St. Louis Railway. 

The section in this pit is shown in Plate XX (No. 10).

The upper dark-bluish clay is gritty and rough textured. It 

weathers to a much lighter color, but the lower light-gray clay has 

a finer texture.

Some glass-pot and crucible clay is obtained from this pit, but the 

inferior siliceous grades are sold for sagger and wad clays.
SEDIMENTARY CLAYS. 271

The various clays produced in the Handle pits, around Whitlock, 

may obviously be used in a number of different kinds of work. In 

general these clays are used in mixtures for white ware, glass pots, 

and crucibles, and in the bond of abrasive wheels and saggers.

The tests given in the following table were supplied by the company:

Chemical analyses of Handle clays from Whitlock, Tenn.

Silica..............

Potash.............

Soda...............

Sulphur............

Mineral composition:

Silica............

Tennessee 

ball 

clay 

No. 5.

46.85

33.15

2.04

.35

.40

.61

.10

.03

16.45

99.98 

94.03

4.65

1.32

Tennessee 

ball 

clay 

No. 5.

44.85

33.15

2.04

.30

.42

.10

.03

18.45

100. 00

TenT 

nessee 

ball 

clay 

No. 4, 

dark.

44.50

35.43

3.25-

.34

.42

.10

.04

15.30

100.00 

93.05

5.70

1 OK

Tennessee 

ball 

clay 

No. 1, 

S.G.P.

53.13

32.82

1.31

.82

.38

.59

.21

.02

10.92

100.00 

90.01

9.01

.98

Tennessee 

ball . 

clay 

No. 7.

w.w.c.

47.26

35.85

1.01

.58

.68

.74

.45

.00

13.43

100. 00 

93.04

6.17

.79

Barbee 

special.

63.54

24.42

1.22

. .60

.63

1.00

.15

.06

8.38

100. 00 

62.94

34.36

2.70

Tennessee 

ball 

clay 

No. 3.

48.50

32.57

2.26

.60

,63

.98

.14

.15

14.16

99.99 

89.04

9.64

1.32

Tennessee 

ball 

clay 

No. 6.

51.57

30.40

2.10

.60

1.25

.68

.14

.10

13.16

100.00

Special selected 

black 

clay.

65.43

22.65

2.00

.50

.70

.55

.14

.03

8.00

100. 00 

49.67

45.79

4.54

Special select- 'ed 

light 

clay.

64.30

24.60

1.56

.43

.55

.42

.10

.04

8.00

100.00 

50.47

45.00

4.53

Physical tests of Handle clays from Whitlock, Tenn.

Fired to a temperature 

(° C.): 

1.050......................

1.075......................

1,100......................

1,125......................

1,150......................

1.175......................

1,200......................

1,230......................

1,260......................

1,290......................

1.320......................

1,350......................

1,375...................... 

1,400......................

1,425...................... 

1,450......................

1,475......................

1,500......................

Modulus of rupture (pounds

Slacking of J-inch cube

Maximum flre shrinkage. ....

Porosity (per cent).

No. 5 

ball 

clay.

38.00 

35.15 

17.98 

13.80 

13. 32 

8.53 

2.94 

.03 

.06 

.15

.69 

.60 

.46 

.02 

.64 

.86 

.52 

1.05 

33* 

2f

466

14 

42.9 

5.57 

14.57

No. 4 

ball 

clay.

42.80 

41.85 

38.75 

36.00 

18.83 

14.65 

14.17 

9.3S 

3.79 

.33

.32 

1.52 

1.61 

1.45 

1.31 

.82 

1.49 

5.27 

35J 

2|

344

12* 

42.9 

5.57 

14.57

No. 1 

ball 

S. O. P. 

clay.

32 

5

303

 12.6 

44 

5.5 

12.0

No. 7 

ball 

W.W. 

C. clay.

33 

6

279

14 

. 45 

5.5 

11.58

Barbee 

special 

clay.

33.86 

32.55 

29.84 

27.88 

24.67 

22.30 

20.13 

19.07 

18.10 

17.92 

15.09 

10.72 

4.92 

3.10 

1.25 

17.40 

17.72 

22.21 

30

407

12 

29.02

5.48 

4.82

No. 3 

ball 

clay.

40.65 

38.60 

35. 50 

18.65 

14.05 

13.74 

8.62 

1.79 

.40 

.35 

.20 

.45 

.60 

.81 

.76 

.97 

1.04 

4.53 

33 

3i

380

14 

43 

5.55 

13.5

i

No. 6 

ball 

clay.

0.35

34J

360

12i 

40 

5.5 

13.5

Special 

selected 

black 

clay.

38.60 

36.10 

35.07 

32.08 

29.95 

27.40 

27.04 

23.18 

22.12 

21.22 

18.60

17.59 

16.93 

6.39 

1.11 

.66 

12.60 

31

466

12* 

30.75 

5.93 

4.63

Special 

selected 

light 

clay.

34.89 

35. 46 

31.32 

30.55 

25.76 

23.99 

22.25 

19.71 

18.28 

16.67 

13.94 

11.93 

8.81 

4.95 

1.04 

' .74 

.65 

6.55 

31

285

8.6 

30.27 

5.46 

4.74

77412 22 20
272 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

PURYEAB, HENKY COUNTY.

Property of Dixie Brick & THe Co. The Dixie Brick & Tile Co. 

has a pit one-fourth of a mile south of Puryear, on the west side of 

the Nashville, Chattanooga & St. Louis Railway. The section exposed at the time of the writer's visit is that shown in Plate XX 

(No. 11).

The overburden is somewhat irregular, and though the terrace 

gravel that caps the clay averages 6 feet in thickness, it becomes 

thinner where the bed of No. 1 light clay and some of the overlying 

sands rise. The upper limit of the sands in places is 8 feet higher 

than the base of the gravel at other places. There is also in places 

a bed of sandstone 1 foot thick between the gravel and the clay. At 

present the pit does not expose the full thickness of the clay. Beds 

2. 3, and 4 are all low in ferric oxide.

The pit at present is being worked for brick clay, although some 

of the material is graded as ball clay.

Nelson in 1911 estimated that the lens underlies 5 or 6 acres. 

The deposit at that time was worked by the Mandle-Sant Clay Co., 

and the product was shipped as ball and sagger clay.

The two following analyses made by K. Langenbeck were supplied 

by the company:

Analyses of clay from Puryear, Tenn.

Combined silica .....................................................................

Free silica.. . ........................................................................

Ferric oxide. ........................................................................

Lime ...............................................................................

Alkalies. ............................................................................

Loss on ignition ................................ .....

1

68.29

.19

22.99

1.43

.40

.42

.22

fi 49

100.36

2

59.83

0

27.80

.83

.15

.24

.82

10.42

100. Of

The upper part of the section in the pit shows a laminated clay, 

which although of good plasticity contains considerable fine grit. It 

burns to a buff color and is steel hard at 1,150° C. At this temperature its absorption is 19.0 per cent and its porosity 28 per cent, 

whereas at 1,300° C. its absorption is only 7.2 per cent and its porosity 

16.3 per cent.

This clay contains a large number of minerals as compared with 

the other clays examined. Quartz and hydromica are common, 

kaolinite is very abundant, and a few grains of tourmaline, titanite, 

rutile, and zircon were noted.

Property of Cooley Ball & Sagger Clay Co. The Cooley Ball & 

Sagger Clay Co., whose office is at Hazel, Ky., has three pits in operation in Henry County, Tenn., just south of the Kentucky boundary 

and about 8 miles northwest of Puryear. These pits are known as 

Nos. 9,10, and 11.
SEDIMENTABY CLAYS. 273

Pit No. 9 is 5£ miles a little south of west" from Hazel, Ky. The 

overburden in the pit is about 17 feet thick and under it lies 7 to 14 

feet of ball clay, which in turn is underlain by 2 feet of sagger clay.27

C. W. Parmelee, who tested the clay, says of it: 28

This clay burns to a good color, has good strength in the unburned state, and 

is quite refractory. It is rather open burning at cone 9 and is a typical ball 

clay. It is suggested that it may be useful for the many purposes for which 

ball clay is used and also in the manufacture of special refractories, chemical 

stoneware, terra cotta, face brick, abrasives, and saggers.

Pits Nos. 10 and 11 are about half a mile south of pit No. 9 and 

are about 600 feet from each other on the west and east sides of a 

hill. Detailed sections are shown in Plate XX (Nos. 12 and 13), 

and a view of the pits is shown in Plate XXIII, B.

The two openings are so close together that they may represent 

different sections of the same deposit and therefore show the amount 

of variation that may occur from place to place in the same clay mass. 

In both pits the overburden, already heavy, will increase greatly if 

the two pits are worked toward the crest of the hill.

Pit No. 11 supplies two grades of ball clay, both from the same bed, 

the upper part of which is known as light ball and the lower part as 

dark ball. The following tests of the light ball clay, made by C. W. 

Parmelee, were supplied by the Tennessee Geological Survey:

General physical tests of liffht ball clay from pit No. 11, 8 miles northwest of

Puryear, Tenn.

Working property________________________ Good. 

Water of plasticity__________________per cent 41 

Modulus of rupture:

Raw clay____________pounds per square inch__ 167. 3

Mixture of clay in proportion of 1:1________do__ 61. 4 

Slaking test ___ ____________minutes 8

Fineness test:

Residue, 20-mesh "sieve____________________ None.

Residue, 60-mesh sieve__________________ None.

Residue, 80-mesh sieve.__________________ None.

Residue, 120-mesh sieve___________________ None.

Residue, 200-mesh sieve (white sand)____per cent_ 0.09 

Drying shrinkage, linear_________________do__ 7. 5

Fire tests of light Hall clay from pit No. 1.1, 8 miles northwest of Puryear, Tenn.

Color. Hardness.

Cone2 (1.170° C.)....................... Gray-white........ Steel hard......... 11.4 28.9

Cone5 (1,230° C.)....................... .....do............. .....do............. 15.7 19.2

Cone 9 (1,310° C.)....................... .....do............. .....do............. 16.3 11.1

Conel2(l,3708 C.)...................... .....do............. .....do............. 17.5

Fusion test: Deforms at cone 33 (1,790° C.).

27 Schroedcr, R. A., Ball clays of Tennessee: The resources of Tennessee, vol. 9, No. 2, 

p. 125, 1919.

28 Idem, pp. 125-126.
274 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

This clay burns to a good color, has good strength in the unburned 

state, and is quite refractory. It is rather open burning at cone 9. 

It is suggested that it will be useful for the many purposes to which 

ball clay is put, and also for the manufacture of special refractories, 

terra cotta, chemical stoneware, face brick, abrasives, and saggers.

A sample of the dark ball clay, when examined under the micro-, 

scope, showed some grains of quartz. Hydromica was abundant and 

somewhat coagulated. Kaolinite was common. Rutile was present 

in numerous tiny grains and needles, and a few grains of zircon and 

chlorite were noted.

The following tests of the dark ball clay, made by C. W. Parmelee, 

were supplied by the Tennessee Geological Survey:

General physical tests of dark ball clay from pit No. 11, near Puryear, Tenn.

Working property_______________Good, slightly sticky. 

Water of plasticity______________ ____per cent 41. 8

Modulus of rupture:

Raw clay_____.______pounds per square inch__ 199

Mixture of clay and sand in the proportion 1:1__do 232 

Slaking test________________ _____minutes__ 7 

Fineness test:

Residue, 20-mesh sieve_____________ _ None.

Residue, 40-mesh sieve ______________ _____ None.

Residue, 60-mesh sieve _________ _________ Trace.

Residue, 80-mesh sieve __________________- Trace.

Residue, 120-mesh sieve (chiefly.white sand) _per cent 0.03

Residue, 200-mesh sieve______________do__ . 11 

Drying shrinkage, linear_________________do__ 6.3

Fire tests of dark ball clay from pit No. 11, 8 miles northwest of Puryear, Tenn.

r«ir>r Warring Shrinkage Porosity Color. Hardness. (percent), (percent).

Cone2(l,170° C.)....................... Gray-white........ Steel hard......... 10.3 33.7

Cone5 (1.230° C.)....................... .....do............. .....do............. 14.1 18.5

Cone9 (1,310° C.)-...................... .....do............. .....do............. 14.7 16.0

Cone 12 (1,370*0.)...................... .....do............. .....do............. 16.6 4.0

Fusion test: Deforms at cone 32 (1,770° C.).

The clay burns to a good color and has good strength in the unburned state. It burns rather open at cone 9 (1,310° C.), has good 

refractoriness, and will be useful for the many purposes to which ball 

clay is put. It may be used in the manufacture of special refractories, chemical stoneware, terra cotta, face brick, abrasives, and 

saggers.

The clay mined in pit No. 10 is regarded as somewhat inferior to 

that obtained from the other two pits. Both ball and wad clay are 

dug.
SEDIMENTARY CLAYS. 275

The following tests of the ball clay, made by C. W. Parmelee, were 

supplied by the Tennessee Geological Survey:

General physical tests of ball clay from pit No. 10, 8 miles northwest of

Puryear, Tenn.

Working property ________________,_________ Good.

Water of plasticity________________per cent_ 35

Modulus of rupture:

Raw clay____________pounds per square inch__ 225 

Mixture of clay and sand in proportion 1:1___do__ 164. 6

Slaking test ______________________minutes__ 7

Fineness test: >

Residue, 20-mesh sieve____________________ None. 

Residue, 60-mesh sieve _________________ None. 

Residue, 80-mesh sieve___________________ None. 

Residue, 120-mesh sieve (white sand)____percent 0.01 

Residue, 200-mesh sieve (white sand)_____do_ .04

Drying shrinkage, linear__________________do__ 5.7 

Fire tests of ball clay from pit No. 10, 8 miles northwest of Puryear, Tenn.

Color. Hardness. shrinkage ,

(percent). (P«c8ni

Cone2 (1,170° C. ....................... Gray-white........ Steelhard......... 11.0 25.4

Cone5 (1.230° C. ....................... .....do............. .....do............. 12.6 10.4

Cone9 (1,310° C. ....................... .....do............. .....do............. 13.1 2.2

Cone 12 (1,370° C.)...................... .....do............. .....do............. 14.0 .26

Fusion test: Deforms at cone 31 (1,750° C.).

This clay burns to a good color and has good strength in the unburned state. It has a good degree of vitrification at cone 9 (1,310° C.) 

and is refractory. It may be used as a ball clay or in the manufacture 

of special refractories, chemical stoneware, terra cotta, face brick, 

abrasives, and saggers.

The wad clay is grittier and burns more open than the ball clay. A 

sample of it, when examined under the microscope, showed that 

grains of quartz and scales of hydromica were fairly common and 

kaolinite was abundant. Kutile was common in tiny grains and 

needles, and there were also a few grains of tourmaline.

At 1,150° C. the clay showed 28.5 per cent porosity and was creamwhite. After firing at 1,300° C. it had 14.8 per cent porosity and was 

light buff.

USES OF LAGRANGE CLAYS OF TENNESSEE.

The clays of the Lagrange formation in Tennessee are used for 

many purposes, as indicated in the foregoing descriptions.

In general, the clays may be subdivided into ball clays, refractory 

bond clays, sagger clays, and wad clays, although the ball clay is 

really a high-grade subtype of the refractory bond clay.
276 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

. More specifically, the first two grades are used in mixtures for different grades of table and toilet ware, sanitary ware, wet and dry 

pressed electrical porcelain, art pottery, smoking pipes, glass pots, 

and graphite crucibles, abrasive wheels, and enamels.

The ball clays have been and are being used successfully as substitutes for the English clays, but care should invariably be taken to see 

that the shipments run uniform, as neglect to do so has sometimes 

caused dissatisfaction.

All the clay is shipped crude.

None of the clay miners report the use of their clay in the unburned 

form, as for paper, paint, etc.

The production of ball clay in Tennessee for the period 1915-1918 

was as follows:

Ball clays marketed in Tennessee, 1915-1918.

Year.

1915.............................................................................

1916.............................................................................

1917.............................................................................

1918o...........................................................................

Short tons.

27, 257

33. 230

40, 282

33,000

Value.

$78,497

110,756

166,589

200,000

a Estimated.

KENTUCKY. 

OCCURRENCE AND DISTRIBUTION.

The eastern border of the Lagrange formation (see p. 259) in Kentucky passes through southwestern Galloway, northeastern Graves, 

middle McCracken, and northern Ballard counties. It then swings 

westward into Pulaski County, 111., not far south of Caledonia Landing, but can not be traced westward across Pulaski and Alexander

counties because of the covering of later deposits.

The deposits of ball clay in Henry County, Tenn., extend beyond 

the State line into Kentucky.

The number of developed localities is not so great as in Tennessee, 

nor have the clays been studied in great detail. It seems probable, 

however, that the Lagrange formation will continue to furnish clay 

of good quality. The largest pits are those at Pryorsburg, south of 

Mayfield, but several firms are operating in the area west of Hickory 

and north of Mayfield.

PRYORSBURG, GRAVES COUNTY.

In the summer of 1918 two companies were operating at Pryorsburg, the Kentucky Construction & Improvement Co., and the Mayfield Clay Co., but the Mayfield Clay Co. has not operated steadily 

since that time.
SEDIMENTARY CLAYS. 277

Property of Kentucky Construction <& Improvement Go. The 

Kentucky Construction & Improvement Co., whose main office is in 

Mayfield, Ky., has been in operation for some years and has rather 

extensive pits on the east side of the Illinois Central Kailroad near 

Pryorsburg station. The deposits are said to underlie about 50 acres.

The clay lens, which is evidently large, appears to trend in a direction N. 20° W., and its upper surface, within the limits of the excavation, is fairly level. The overburden, because of surface irregularities, ranges from 36 to 60 feet.

The section, measured in 1918, as shown in Plate XX, No. 14, is 

quite varied; indeed it probably exhibits a greater number of beds 

than any other section measured in Kentucky or Tennessee.

These different beds, exclusive of the overburden, have a total 

thickness of about 37 feet. Immediately under the overburden at 

the north end of the pit occurs a lens of.lignite, which is 12J feet 

thick in the center, and tapers out to a thin edge in both directions. 

It is mostly fine grained and shows comparatively few woody fragments.

The sagger clay, which is light gray and has a dark seam in the 

center, seems to be missing in the old pit.

The No. 3 ball clay corresponds to No. 4 of the old mine, where 

it lay directly below the lignite. This clay is used in the manufacture of crucibles, tiles, and white ware. It is also said to have 

been employed as an ingredient of steel enamels.

The. following tests of this clay were made in the laboratory of 

the Bureau of Mines at Columbus, Ohio:

General physical tests of clay No. 3, Kentucky Construction & Improvement

Co., Pryorsburg, Ky.

Workability______-Very plastic, sticky; pulls under spatula. 

Water of plasticity_____ ___ ___per cent 41.72 

Air shrinkage, by volume._ _ _ _ do 31.92 

Air shrinkage, linear, calculated . do_'_ 12.00 

Modulus of rupture:

Raw clay_____'. pounds per square inch__ 25. 55 

Mixture of clay and sand in proportion 1:1__do__ 196.30

Fire tests of clay No. S, Kentucky Construction & Improvement Co., Pryorslurg, Ky.

Temperature (°C.).

1,190...........................

1,250...........................

1,310...........................

1,370...........................

1,410...........................

Porosity 

(percent).

16.70

16.79

1.59

.90

.30

Color.

.....do............................

.....do............................

.....do............................

Volumetric 

shrinkage 

(per cent 

in terms 

of dry clay).

32.00

29.89

37. 52

40.00

38.00

Linear 

shrinkage 

(per cent 

in terms of 

dry clay).

12.00

11.20

14.50

15.60

14.70

Fuses at cone 32+ (1,770° C.-f). Steel hard at 1,190° C. At 1,310° C. the 

clay shows small yellowish specks.
278 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

This clay shows only moderate bonding strength. It fires to a 

dense body at 1,310° C., and the color is fair but not equal to that of 

the best ball clay. It can be used as an ingredient of pottery, tile, 

and other bodies where this type of clay is desired.

The following tests of clay No. 5 were made in the laboratory of 

the Bureau of Mines at Columbus, Ohio:

General physical tests of clay No. 5, Kentucky Construction & Improvement Co.,

Pryorsburg, Ky.

Workability_____Plastic, tough; molds well; warped in drying. 

Water of plasticity_________________percent 34.47 

Air shrinkage, by volume.' ____________do__ 26.34 

Air shrinkage, linear, calculated__________;_do__ 5.82 

Modulus of rupture:

Raw clay___ _pounds per square inch_ 189.1 

Mixture of clay and sand in proportion 1:1___do__ 167.5 

Fineness test:

Residue on 150-mesh sieve___________per cent_ 1.27

Fire tests of clay No. 5, Kentucky Construction & Improvement Co., Pryorsburg, Ky.

Temperature ( eC.).

1,190........................... i 9«m

1,310...........................

1,370...........................

1,410...........................

Porosity 

(per cent).

18.33

18.33

10.84

.60

.40

Color.

Cream-white. . ....................

.....do............................

.....do............................

Buff. .............................

.....do............................

Volumetric 

shrinkage 

(per cent 

in terms 

of dry clay).

28.30

29.64

33.41

38.20

37.50

Linear 

shrinkage 

(per cent 

in terms of 

dry clay).

10.4

11.0

12.7

14.8

14.5

Fusion point, cone 31 (1,750° C.). Steel hard at 1,190° C.

This clay shows moderate bonding strength and fair refractoriness. It fires to a dense body of creamy-white color at 1,370° C. 

If mixed with other clays it could be employed in pottery and tile 

bodies, abrasives, sanitary ware, chemical stoneware, and similar 

products.

The highly lignitic clay between the No. 3 clay and the next lower 

ball clay is thrown out.

Ball clay No. 7 is chocolate-colored above and lighter below. The 

whole bed shows somewhat bright colorings. It is of value for glass 

pots.

Underneath the ball clay come several beds usually called fire 

clays, which have been opened at a lower level. They appear to be 

somewhat similar to each other but are separable into several grades. 

The upper clay, known as No. 5 ball, is mixed with the lower fire 

clay and is of use in the clay bond of abrasive wheels.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXV

A. WORKING FACE OF PIT OF KENTUCKY CONSTRUCTION & IMPROVEMENT 

CO., PRYORSBURG, KY.

E. PIT OF EDGAR PLASTIC KAOLIN CO., EDGAR, FLA.
U. 8. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXVI

A. SHAFT HOUSE AND STORAGE SHED AT GANTS MINE, NEAR MOUNTAIN 

GLEN, UNION COUNTY, ILL.

B. OLD PIT OF ILLINOIS KAOLIN CO., NEAR MOUNTAIN GLEN, UNION

COUNTY, ILL.
SEDIMENTARY CLAYS. 279

Clay No. 6, which underlies clay No. 5, is used to some extent in 

glass-pot mixtures and also for bats in making abrasive wheels. 

Clay No. 7 lies next below and is not quite as short as clay No. 6.

The clay deposit is underlain by sand.

The pit is a large opening, but at the time of the writer's visit a 

rather small face was being worked. (See PI. XXV, A.)

After the overburden is removed with a steam shovel the clay is 

dug with mattock and shovel. It is then loaded on small dump cars 

that hold a ton, hauled to the foot of an incline, and drawn up to 

the storage bins.

A microscopic examination and also a few fire tests were made of 

several clays from this pit, with the following results:

No. 3 ball clay is of nonlignitic character and is highly plastic, 

smooth, and fine-grained. It contains very little quartz but a great 

abundance of hydromica. Kaolinite is common, but rutile is scarce.

At 1,300 C. it burns light cream and has 0.8 per cent absorption and 

1.4 per cent porosity. A thin section of the burned clay, when examined under the microscope, shows an exceedingly fine-grained 

feltlike mass that has low interference colors.

Old No. 4 ball clay is also a smooth plastic clay that carries very 

little quartz. Hydromica is abundant and much coagulated. Kaolinite 

is common, and rutile occurs in numerous tiny grains. At 1,300° C. 

the clay burns cream-white and has 1.8 per cent absorption and 2.5 

per cent porosity.

No. 5 clay is medium to 'fine grained but is very plastic and 

smooth. Under the microscope it shows little quartz. Hydromica 

is common and kaolinite is much more abundant. Eutile occurs 

sparingly. At 1,300° C. it burns cream-white and has 14 per cent 

absorption and 28.7 per cent porosity.

Pit of May-field Clay Co. The pit of the Mayfield Clay Co. is on 

the east side, of the Illinois Central Kailroad, near Pryorsburg station, and in June, 1918, had been in operation about a year. It lies 

at a slightly lower level than the other pit, and the clay is totally 

different in appearance from the clay in the pit of the Kentucky 

Construction & Improvement Co. It is nearly all grayish black.

The overburden in the pit is from 12 to 15 feet thick and under 

this occurs a mass of clay which is almost black but becomes light 

colored as it dries. (See PI. XX, No. 15.)

About 7 acres had been tested, and this area contained 18 to 23 

feet of clay.

Although the clay at first appears somewhat similar from top to 

bottom, close examination shows a variation in the texture and 

plasticity. The bed is therefore separated into an upper part, which 

is a sagger clay that contains fine laminae of sand, and a lower part, 

which is smoother and is classed as ball clay.
280 HIGH-GRADE CLAYS OP THE EASTERN UNITED STATES.

A specimen of the No. 3 ball clay, which is very plastic and smooth, 

was found on microscopic examination to be fine grained. Quartz 

was common, and hydromica was very abundant and coagulated. 

Kaolinite was common but less abundant than the hydromica. A 

few grains of tourmaline and rutile were present. When fired at 

cone 10 (1,330° C.) the clay burned a light buff, and its absorption 

was 1.2 per cent and its porosity 3.6 per cent. The material when 

dry is gray. It contains some fine grit but forms a very smooth 

plastic mass when wet.

A sample of sagger clay, which is very plastic, was medium to 

fine grained. Quartz was common. Hydromica was abundant and 

commonly coagulated, and kaolinite was likewise abundant. Rutile 

was present in numerous tiny grains, and there were a few grains 

of tourmaline. At 1,150° C. the clay showed 14.1 per cent absorption, but at 1,300° C. it showed 11.9 per cent absorption and was 

cream-white. It was steel .hard at the lower temperature. A thin 

section, of the burned clay showed a compact mass, of the type commonly developed when hydromica is abundant. Quartz was moderately abundant and was embedded in a groundmass which is partly 

isotropic and partly composed of material that shows a low interference color. The isotropic material was more abundant in the clay 

that was fired to the higher temperature. At this higher heat 

the grains of rutile still preserved their identity.

The output is used chiefly in the manufacture of whiteware.

HICKORY GROVE, GRAVES COUNTY.

Pit of Old Hickory Clay dk Talc Co. A new development, started 

by the Old Hickory Clay & Talc Co., is 2^ miles northeast of Hickory 

Grove. Only a small pit had been opened in June, 1918, but about 

6 acres has been tested and is underlain by clay, whose maximum 

thickness, as determined partly by boring, was about 40 feet.

The section given in Plate XX (No. 16) is compiled partly from 

the pit and partly from drill records. It shows 3 grades of clay 

No. 1 ball, wad, and sagger.

The ball clay, which is very smooth and plastic, is very fine 

grained. Under the microscope it showed a few small grains of 

quartz. Hydromica, fine grained and coagulated, is abundant. 

Kaolinite is common and rutile scarce. A sample that was fired at 

two temperatures gave the following results:

Since June, 1918, this property has changed hands and has been 

developed much more. The section now shows sagger clay at the 

top and several grades of ball clay below. The following tests have 

been supplied by the present operators:
SEDIMENTARY CLAYS. 281 

Physical tests of clays of Old Hickory Clay & Talc Co., Hickory, Ky.

Plasticity............................

Air shrinkage by volume in terms

Modulus of rupture for mixture of claj

Slaking time of mixture of clay anc

Temperature when burned steel hard. 

Linear fire shrinkage when burned 

temperatures (° C.): 

1,230.............................

1,270..............................

1,310..............................

1,370..............................

1 450

of volume of

pounds per square inch. . 

r and sand in 

pounds per square inch. . 

f flint in pro-

..................( C.)-

to following

...................do....

...................do....

...................do....

Porosity when burned to following temperatures (° C.):

1,150. ............ . . . nar rant:

1,230..............................

1,270...............................

. 1,310..............................

1,370..............................

1,450..............................

...................do....

...................do....

...................do....

...................do....

Sagger 

clay 

A.

Very 

good. 

25

7

25 

280

137

9 

1,150

7.25 

10.00 

9.00 

10.50 

11.50

27.30 

23.76 

21.70 

17.80 

9.00 

9.40 

Creamwhite.

Ball 

clay 

B.

Very 

good. 

37.7 

6.7

25 

249

137

8 

1,150

11. 75 

12.50 

13.00 

14.00 

13.50

27.90 

20.10 

19.00 

9.60 

3.00 

3.30 Creamwhite.

Ball 

clay 

C.

Very 

good. 

40 

6.5

30 

401

143

7 

1,150

11.0 

12.5 

12.5 

15.0 

16.00

30.1 

19.4 

17.9 

16.0 

3.8 

2.5 

Creamwhite.

Ball 

clay 

D.

Very 

good. 

31.5 

5.25

26.8 

263

102

5 

1,150

8.7 

11.0 

11.0 

11.0 

10.5

24.4 

 16.9 

14.0 

5.1 

1.1 

.4 Creamwhite.

Pit of Colonial Clay Co. Recently Mr. C. E. Jennings, of 

Paducah, Ky., has started the development of another clay property 

just west of the property of the Old Hickory Clay & Talc Co. He 

has 200 acres under lease on the Wyatt and Moses farms, which he 

claims is underlain by a white ball clay that ranges from 22 to 38 

feet in thickness.

The following analysis of a sample from this property was furnished by Mr. Jennings:

Analysis of clay from Jennings pit, Hickory Grove, Ky. 

Silica ________________________________ 58. 6 

Alumina _______________________________ 22. 7 

Magnesia _____________________________I Trace. 

Loss on ignition__________________________ 15.2 

Alkalies by difference_______________________ 3. 5

100.0

Pit of National Sales Co. The National Sales Co., whose main 

office is at Cincinnati, Ohio, has a pit 2 miles west of Hickory Gfrove. 

On the west side this pit shows the following section r

Section in west side of pit of National Sales Co., HicJcory Grove, Ky.

Feet.

Overburden of gravel______________________ 9-12 

Sagger clay _______ ______ 15-16

On the east side of the pit, about 50 feet distant from the west 

side, the section is as follows:
282 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Section in east side of pit of National Sales Co., Hickory Grove, Ky.

Feet.

Overburden_____________________________ 10 

Light bluish-white ball clay__ ________________ 6 

Sagger clay, gray; has red mottlings________________ 2

The company controls 30 acres. The clay is hauled by wagon 

to Hickory Grove.

Other firms which have begun to mine clay in the region west of 

Hickory Grove since the field work for this report was done are 

the Kentucky Clay Mining Co., the West Kentucky Clay Co., and 

the M. B. Cooley Clay Co.

WICKLIFFE, BALLARD COUNTY.

The occurrence of high-grade bond clays in the vicinity of Wickcliffe was mentioned by the Kentucky Geological Survey in 1888, 

and the clays have been worked in a small way for some years. All 

the excavations are small and are close to town.

La Clede-CJiristy Clay Co. The main office of the La CledeChristy Clay Co. is in St. Louis, Mo. The company has opened two 

pits about two-fifths of a mile south of Wickliffe. Both of them 

lie within an area of about 2 acres, and one is at a slightly higher 

level than the other. (See PI. XX, Nos. 17 and 18.) Neither pit 

shows a very thick section or a great variety of clay types.

The sandy clay and the black clay are sold to glass-pot manufacturers, but five different grades in all are sorted out. One grade is 

used in the manufacture of lead pencils.

American Clay Co. The American Clay Co., whose office is at 

Muncie, ind., operates a pit half a mile northeast of Wickliffe. The 

section is given in Plate XX, No. 19. The deposit was worked for 

about three years prior to June, 1918.

The clay is sorted into two grades. Clay No. 2, which ranges 

from 5 to 8 feet in thickness, lies on top and is underlain by clay 

No. 1, a fine-grained fat clay that has a similar range of thickness.

The clays are dried by heating before shipment, a practice that 

is not followed at any other pits in Kentucky or Tennessee.

Some of the clay from! this pit has a composition similar to the 

Gross Almerode glass-pot clay but shows a higher shrinkage than 

that clay and is softer when burned. It can be used to mix with 

other clays in the manufacture of glass refractories.

UNDEVELOPED LAQEANOE CLAYS IN KENTUCKY.

There may still be many undeveloped deposits of clay in the 

Lagrange formation in Kentucky.

Two properties which have not been producers are those of the 

Galloway County Clay Co., 6 miles east of Murray, Galloway County,
SEDIMENTARY CLAYS. 283

and the United States Clay Co., near Wiatts schoolhouse, 10 miles 

from Murray. Other deposits are known, but most of them are too far 

from the railroad to permit their present development.

Berry 20 gives the following section in the Illinois Central Kailroad cut near Wickliffe, Ky.:

Section near Wickliffe, Ky.

Feet.

Heavy gravel, all sizes______________________ 10 

Fine to coarse, yellowish or reddish ferruginous sand__ 8-13 

Iron crusts and water-bearing horizon ' 

Gray plastic clay with scattered lignite __________ 12 

Concealed to track level____ _ _ ___,__ 7

The section 100 yards north of the section just given is as follows:

Section 100 yards north of preceding section.

Feet. 

Mostly concealed, loamy loess_ __ ____<. _________ 25

Gravel and sand 20 

Argillaceous lignite _ ___________ _____________ 4

Clay or sand 8 

Lignite, about ________________ _________ 4

Clay or sand, about-_ _______ ______ 10

This section is not as promising as the one preceding it. 

Prospecting will no 'doubt develop additional deposits in the 

Lagrange beds, and there are others which are being held in reserve.

USES OF LAGRANGE OLAYS OF KENTUCKY.

In general the Lagrange clays mined in Kentucky are utilized as 

ball clays in white ware and high-voltage insulators; in mixtures 

with other clays for glass refractories, graphite crucibles, and the 

bond for abrasive wheels; and in saggers. One pit has supplied clay 

for lead pencils. Of course, the same grade of clay is not employed 

for all these purposes. The ball clays have an excellent reputation.

Mixtures of clays from Kentucky, St. Louis, and Mississippi 

should work well for glass refractories.

The production of ball clays in Kentucky for the years 1917-1918 

is reported as follows:

Ball clays marketed in Kentucky, 1915-1918.

Year.

1915.............................................................................

1916................... .........................................................

1917.............................................................................

1918o...........................................................................

Short tons.

13.677

15,282

17,858

20,000

Value.

$45,199

50,831

98,736

113,000

a Estimated.

29 Berry, E. W., The lower Eocene floras of southeastern North America: U. S. Geol. 

Survey Prof. Paper 91,-1916.
284 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

ILLINOIS.80 

DISTRIBUTION AND OCCURRENCE.

Deposits of fire clay near Mountain Glen, Union County, 111., have 

been known for many years, but there was no serious development 

until the European war cut off the importations of high-grade German refractory clays.

These clays occur in the northwestern part of Union County, near 

Mountain Glen, on the Mobile & Ohio Railroad.

The bedrock includes Devonian, Mississippian, and Pennsylvanian 

shales and limestones, but these bear no genetic relation to the clays. 

Above the clays there is a general covering of loess, which ranges 

from a few feet to 15 feet or more in thickness, and this is underlain 

by a gravel bed whose thickness ranges from 3 inches to 2 feet in the 

hillside deposits up to 8 feet in the deposits in the .lowland along the 

east branch of Clear Creek.

In typical exposures white and pale-red fine-grained micaceous 

sands underlie the gravel bed. These sands have a maximum thickness of 20 feet in some places but are absent in other places. Below 

all these beds lies the fire clay.

The large pit of the Illinois Kaolin Co., no longer worked, shows 

the following section:

Section in pit of Illinois Kaolin Co. near Mountain Glen, III.

Feet. 

Fire clay,- pink_ ________________ _ _ 15

White clay ________________________ 1-10 

Bluish-white clay containing lignite in some places; maximum________________________________ 40

Clay and lignite; maximum______ ___________:_ 17

White and red water-bearing sand.

A view of this pit is shown in Plate XXVI, #, and sections exposed 

in it are given in figure 38.

Sand lenses occur in places in the clay, especially near the edge of 

the deposit.

At a few small prospects, which are well up on the hillsides, the 

conditions of occurrence are similar to those found in the main deposits, but the clay is apparently of different quality.

The bedrock is probably limestone,-and the clays appear to occupy 

depressions within it.

One deposit of the pink clay showed a thickness of 93 feet. The 

highest elevation of the bluish-white and white clay seems to be 

from 470 to 475 feet above sea level. Other clays in the vicinity extend about 100 feet higher, but they are of different grade.

80 St. Clair, Stuart, Clay deposits near Mountain Glen, Union County, 111.: Illinois Geol. 

Survey Bull. 36 (extract), 1917.
SEDIMENTARY CLAYS. 285

ESE.

".Gravel

The clays are undoubtedly of sedimentary origin, although as 

there are several large faults in the district, some of the smaller 

deposits might be due to the alteration of rock along fault planes. 

Some difficulty has been found in correlating these clays with those 

of Kentucky and Tennessee, but the Illinois Geological Survey regards them as probably of Wilcox age. This correlation is also applied to the refractory clays elsewhere in southern Illinois. It is 

based on their distribution and their resemblance to the clays at 

Hickory and north of Mayfield, Ky. These resemblances include a 

similar content of lignite; similarity 

in texture and color; a rather conspicuous uniformity of elevation; 

and, so far as the tests have progressed, a striking similarity in refractoriness and other qualities.

According to St. Clair the clays 

were laid down in depressions of the 

old land surface within the limits of 

the embayment area. If this view of 

their origin is correct then we may 

expect to find clay bodies only where 

there were depressions in the land 

surface over which the waters of 

these early times extended. St. Clair 

says :31

The favorable places for deposition 

would be in small ,embayments, where the 

movement of the water would be so slight as to allow the fine clay material held 

in suspension to settle, yet where fresh supplies could be continually introduced. 

Such conditions as these would probably not obtain along the main arm of 

the sea. Therefore in the smaller reentrants we should expect to find clay deposits commensurate with the size of the surface depressions in which the clay 

could settle.

The clays are worked in the region around and to the north of 

Mountain Glen. One company, the Illinois Kaolin Co., worked its 

deposit with steam shovels in a large open cut, but at the time of the 

writer's visit in June, 1918, this pit had been abandoned. The other 

operators in that district, including the French Clay Blending Co., 

F. E. Bausch, Dr. Goodman, and others, were mining the clay with 

shafts. (See PI. XXVI, A)

CHARACTER AND USES OF THE CLAYS.

Much of the clay mined in this area is satisfactory in the manufacture- of glass pots and graphite crucibles and as an ingredient of the 

oond for abrasive wheels.

FIGURE 3S. Sections of deposit of 

Illinois Kaolin Co., near Mountain 

Glen, 111.

81 St. Clair, Stuart, op. cit, p. 80. 

77412 22 21
286 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The better grades of the "clay are refractory, are of excellent 

plasticity, and show -a low porosity from cones 5 to 9 (1,230° to 

1,310° C.). '

One sample of white clay from the Goodman shaft, which was examined under the microscope, showed much quartz and hydromica. 

Kaolinite was abundant in bunches, and rutile in tiny grains was 

common. This clay had a porosity of 33.4 per cent at 1,150° C.

The following tests were made by C. W. Parmelee, of the University of Illinois:

Sample 1 is a bluish-white clay from a depth of 58 feet below the 

surface or 50 feet below the top of the clay bed. Sample 2 is a bluishwhite clay taken 30 feet below the top of the pink clay and 15 feet 

below the top of the bluish-white clay. Sample 3 is a pink clay taken 

from the pit and was about 10 feet from'the top of the clay bed:

Sample 1, bluish-white clay from Union County, III. 

Color _________ ____________-____ Bluish white. 

Plasticity_______________ - - - Very good. 

Water content required , _ per cent 32.8 

Molding properties__________ Formed readily by hand and

flowed easily through a die.

Tensile strength of dry briquets. pounds per square inch 124 

Bonding strength (tensile strength of a mixture of equal parts

of clay and standard Ottawa sand).pounds per square inch_ 95. 3 

Slaking test (time required for a mixture of equal parts 

of potter's flint and clay formed into J-inch cubes to 

disintegrate when submerged in water at room temperature) ___-___----- __ minutes 21 ! 

Fineness test of clay deflocculated by use of an appropriate amount 

of sodium carbonate:

Residue, 20-mesh sieve______________per cent 0.00 

Residue, 40-mesh sieve ________________do__ . 04 

Eesidue, 80-mesh sieve _______________do__ . 24 

Residue, 100-mesh sieve _ _ do . 21 

Residue, 200-mesh sieve.______________do__ .53

Total residue_________________________ 1.02 

Drying shrinkage of the clay formed into bars by forcing the 

plastic body through a die________;______per cent_ 6. 7

Fire tests of sample 1, bluish-white clay from Union County, IlL

Hardness.

Cone08(990° C.)....................... White............ Scratched with 37.0 2.75

knife.

Cone06(1,030°C.)-.................... .....do............ .....do............ 36.7 3.25

Cone04(1,070°C.)..................... .....do............ .....do............ 36.9 3.25

Cone02(l,110°C.)..................... .....do............ Steel hard......... 33.7 4.0

Cone 1(1,150°C.)...................... .....do............ .....do............ 33.7 4.0

Cone 3 (1,190° C.)...................... .....do............ ....xdo............ 23.0 7.7

Cone5 (1.230° C.)...................... Bluestone......... .....do............ 3.25 11.0

Cone 7(1,270° C.)...................... .....do............ . . .do ........... 3.25 11.5

Cone9 (1,310" C.)...................... .....do............ .....do............ 3.5 11.25

Showed much checking during the burning.
SEDIMENTAEY CLAYS. 287

Fusion test: Small cones tested in gas-and-oil burning furnaces deformed 

(fused) between con«s 32 and 33 (1,770° and 1,790° O.).

Sample 2, bluish-white clay from Union County r IK

Color___________________________Bluish white. 

Plasticity________________,_^____-____Very good. 

Water content required --_____________per cent_ 34.6 

Molding properties_______Formed readily by hand and flowed

easily through a die.

Tensile strength of dry briquets__pounds per square inch__ 132 

Bonding strength _____________________do__ 89

Slaking test _ _ _ _________minutes__ 29

.Fineness test:

Residue, 20-mesh sieve______________per cent__ 0.00 

Residue, 40-mesh sieve________________do__ .02 

Residue, 80-mesh sieve__________.,_____do__ . 11 

Residue, 100-mesh sieve __ do .09 

Residue, 200-mesh sieve... do .20

Total residue ______ _ __________ . 42 

Drying shrinkage__________ _ ___ _ __ 7.2

Fire tests of sample 2, bluish-white clay from Union County, III.

Color TTarrtnP^ Porosity Shrinkaj Color. Hardness. (percent), (percent

Cone 08 (990° C.)....................... White............. Scratched with 36.2 3.0

knife.

Cone06 (1,030° C.)...................... .....do............ .....do............ 36.0 3.2

Cone 04 (1,070" C.)...........................do.................do............ 36.0 3.2

Cone02 (1.110° C.)..................... .....do............ Steelhard......... 32.2 5.0

Conel 1,150°C. .......:.............. .....do............ .....do............ 32.5 4.5

ConeS 1,190'C. ...................... Light bufl........ .....do............ 21.2 8.2

Cone5 1,230° C. ...................... Bluestone......... Vitreous.......... 2.5 11.0

Cone? 1,270°C. ...................... .....do............ .....do............ 3.2 11.2

Cone9 1,310° C. ...................... .....do............ .....do............ 3.0 11.2

Fusion test: Deforms between cones 33 and 34 (1,790° and 1,810° C.).

Sample 3, pink clay from Union County, III.

Color __________________________ Dark rose-pink.

Plasticity ____ _ Very good.

Molding properties______ Soft, easily crushed; formed

readily by hand.

Tensile strength of dry briquets__pounds per square inch__ 95. 5

Drying shrinkage__ ,_________ _______:_per cent 5.9

Slaking test _ __ _ ________ minutes 30

Fineness test:

Residue, 40-mesh sieve___________*_per cent 0.00 

Residue, 60-mesh sieve________________do__ .10 

Residue, 100-mesh sieve_______________do__ .14 

Residue, 200-mesh sieve_______________do__ .16

Total residue ________________-_____ .40
288 HIGH-GRADE CLAYS OF THE EASTERN" UNITED STATES. 

Fire tests of sample 3, pink clay from Union County, III.

08 (990° C.)»...........................

06 (1,030° C.)................. ..........

04 (1,070° C.) ...........................

02 (1,110° C.) ...........................

1(1,150° C.)..........-.............'....

3(1,190° C.)..........-.................

5(1,230" C.)...................-.. ......

7 (1,270° C.)............................

9(1,310° C.)..................... .......

10 (1,330° C.). ..........................

Color.

Pink..'............

.....do............

.....do............

.....do............

.....do............

.....do............

.....do. . ..........

.....do............

Hardness.

Steel hard. ........

.....do............

.....do............

.....do............

.....do............

.....do............

.....do............

.....do............

.....do............

Porosity 

(percent).

35.5

35.5

34.2

31.8

28.0

12.5

6.5

2.8

3.6

3.6

Shrinkage 

(per cent).

3.0

3.0

3.5

4.7

6.5

10.0

10.0

10.0

10.0

10.0

Fusion test: Deforms between cones 33 and 34 (1,790" and 1,810° C.).o

These tests show similar pyrometric qualities as those which have 

already been reported for samples of clay which were taken from 

pits in the Mountain Glen district many years ago. 32 Chemical 

analyses of the old samples are tabulated below. Sample D10 was 

taken at a depth greater than 50 feet; sample Dll, at a depth of 40 

to 44 feet; sample D12, at a depth of 35 to 40 feet; samples D13 and 

D14 were taken from the stock crib and represent the beds from the 

top of the deposit to a depth of 20 feet.

Analyses of clays from Mountain Glen district, III.

Silica (Si02).........................................

D10

43.90

40.79

1.76

2.40

1.25

9.90

100. 00

Dll

48.30

31.14

1.02

3.20

.97

15.37

100.00

D12

56.55

29.97

1.23

2.75

.86

8.64

100.00

D13

47.95

37.86

1.23

3.01

.90

9.05

100.00

D14

52.65

33.98

.97

2.92

.87

10.61

102. 00

Prof. C. W. Parmelee, of the Department of Ceramic Engineering 

of the University of Illinois, makes the following statement in regard 

to the uses and commercial qualities of the bluish-white clay as 

indicated by mechanical and pyrometric tests of samples 1 and 2:

This material is a very fine grained, plastic, strong, highly refractory clay, 

well suited for use as a bond clay in the manufacture of high-grade refractories. 

Although its properties are not quite the same as those that characterize the 

European bond clays heretofore extensively imported for use in the manufacture of graphite crucibles, crucibles for melting brass, and other purposes, 

yet this clay approaches so nearly to the European clays as to warrant the 

belief that it may be used for the same purposes.

The clay may be used also where a good bond clay is required, as in the 

manufacture of chemical stoneware. Possibly further experiments may show 

that this clay may be substituted in certain products for ball clays, providing 

that the dark color developed by these clays at the higher temperatures is not 

objectionable.

*> Purdy, R. C., and De Wolf, F. W., Preliminary Investigations of Illinois fire clays: 

Illinois Geol. Survey Bull. 4, p. 175, 1907.
SEDIMENTARY CLAYS. 289

As already stated (p. 285), these clays are being satisfactorily used 

in place of the European clays in the manufacture of graphite 

crucibles and glass pots.

In regard to the commercial qualities of the pink clay, sample 3, 

Prof. Parmelee says:

This clay is similar to clays 1 and 2 (bluish-white) in that it is a highly 

refractory bond clay and is suited to the purposes previously mentioned. This 

clay differs slightly with respect to the cone temperature at which it first 

attains its minimum porosity. Clays 1 (1,150° C., and 2 (I,i70° C.) show a 

minimum porosity attained at two cones lower than clay 3. This characteristic 

is likely to render clays 1 and 2 better suited to use for graphite crucibles.

An unusual feature of this clay is the retention of a pink color (lilac at 

the higher temperatures) up to cone 5 (1,230° C.). This is most unusual, and 

a chemical analysis of the clay would be of much interest.

It is our opinion that the color of the clay does not affect its intrinsic 

value for the purposes mentioned and that any method of decolorizing the

clay would be prohibitively expensive and of no real advantage.

OLIGOCENE CLAYS.

FLORIDA. 

DISTRIBUTION AND CHARACTER.

The white clays of Florida, "plastic kaolins," as they are usually 

called, form a unique type of material. Their use was recognized 

more than 20 years ago, and they have been mined ever since by a few 

companies.33

The formation in which the clay occurs is of Tertiary age, but its 

exact position in the beds laid down in this period is not known. 

Sellards says that it overlies the Oligocene limestones, but that there 

is also some reason for "believing that it lies at a stratigraphic level 

higher than the beds of fuller's earth and hence is not older than 

the Miocene." However, as no one of the later fossiliferous formations overlies the clay, its age can not be fixed more definitely. The 

clay is probably coextensive with the "lake region" of Florida 

that is, it probably extends from Clay County on the north to the, 

middle of De >Soto County on the south. Its length, therefore, is 

about 150 miles and its width from 10 to 40 miles.

According to Sellards, an area which has a similar type of topography and is underlain probably by the same formation occurs in 

several counties of western Florida, between Suwannee and Choctawhatchee rivers.

M Ries, H., The clays of the United States east of the Mississippi River: U. S. Geol. 

Survey Prof. Paper 11, p. 83, 1903. Matson, G. C., Notes on the clays of Florida: U. S. 

Geol. Survey Bull. 380, pp. 346-357, 1909. Sellards, E. H., Mineral industries and resources of Florida: Florida Geol. Survey Sixth Ann. Rept, p. 23, 1914 ; Clays of Florida: 

Am. Ceramic Soc. Jour., vol. 1, p. 313, 1918.
290 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

The clays are sedimentary and consist of a mixture of particles of 

clay, grains and pebbles of quartz, and mica. The overburden as a 

rule is composed of loose sand, and at the localities worked it ranges 

from 4 to 10 feet in thickness.

The sandy clay is gray, some of it iron-stained in its upper part, 

and has a maximum thickness of 30 feet. It is underlain by a sticky 

blue clay, which is left alone in mining.

The clay is dug at Edgar, Putnam County, by the Edgar Plastic 

Kaolin Co., and at Okahumpka, Lake County, by the Lake County 

Clay Co. and the Florida China Clay Corporation.

The material as excavated is very sandy and has to be washed to 

eliminate the sand, so that the washed product probably does not 

average over 15 per cent of the material excavated. The sand is usually coarse and sharp and affords an excellent building material.

The method of excavating the clay is unique. It consists in floating a dredge in the pit (PL XXV, B) and in forcing the dredged 

clay with water through a pipe to the washing plant.

The clay from this region is plastic, burns white, and is refractory 

but has a rather strong shrinkage. It is utilized almost exclusively 

in making pottery and decorative tile.

There are probably abundant reserves, so that production could be 

greatly increased.

In mineral composition the clay does not differ materially from 

many of the other clays examined. N

In the crude material quartz is very abundant and coarse, a fact 

that is easily seen with the naked eye. Hydromica does not appear 

to be very common, but kaolinite is abundant in large and small 

flakes and also in fan-shaped masses. Rutile is very scarce, and there 

are a few grains of chlorite and zircon.

The washed clay is medium to fine grained. It shows very little 

quartz. Hydromica is fairly abundant and commonly coagulated, 

although there are some large single grains. Kaolinite is abundant, 

mostly in fine grains, though there are a few large ones. There are 

a few grains of rutile and zircon.

Thin sections were cut of pieces that had been fired to 1,150° C. 

and 1,300° C., respectively. These sections (Plate XXX, B) showed 

very little quartz and consisted of a fine groundmass, which in the 

specimen that was fired to the lower temperature showed considerable isotropic material together with small flakes of low interference 

color. In the piece that was fired at 1,300° the groundmass showed 

a distinctly felty appearance, with more material of low interference 

color.

The raw clay contains a few slivers of material, either kaolinite or 

a low grade of hydromica, which are larger than the other flakes.
SEDIMENTARY CLAYS. 291

On firing these slivers, or some of them, retain their shape and 

simply lose a little of their interference color, but others are converted to sillimanite.

The following tests of the washed clay from Okahumpka, Fla., 

were made in the laboratory of the Bureau of Mines, at Columbus, 

Ohio:

General physical tests of washed clay from Okahumpka, Fla.

Workability ___^_^__________ Very plastic; molds well. 

»Water of plasticity, in terms of dry clay_____per cent 49.78 

Air shrinkage by volume________________do__ 32.15 

Air shrinkage, linear, calculated____________do__ 12.20 

Modulus of rupture _______pounds per square inch__ 181.00

Fire tests of clay from Okahumpka, Fla.

Temperature (°C.).

1,190...........................

1,250...........................

1.310...........................

1,370...........................

1,410............................

Porosity 

(per cent).

28.3 '

27.05

23.41

7.4

2.2

Color.

White............................

.....do............................

Buff. .............................

Volume 

shrinkage 

(per cent 

in terms 

of dry clay).

32.1

33.11

37.33

16.3

49.4

Linear 

shrinkage 

(per cent in 

terms of 

dry clay).

12.1

12.5

14.4

18.7

20.3

Deformation temperature, cone 31+ (1,750' 

Develops small cracks in firing.

C.). Steel hard at 1,190° C.

The clay fires to a good color and shows moderate strength in its 

unfired condition. It is not to be classed as a bond clay. It is extensively used in different kinds of white ware.

USES OF OLAYS OF FLORIDA.

The white clay of Florida is extensively used in the manufacture 

of white ware, electrical porcelain, and floor and wall tile. It is 

not usually regarded as a paper clay. It has also been used in manufacture of porcelain, glass pots, fine optical glass, and in the making 

of certain classes of munitions.
MICROSCOPIC STUDY OF CLAYS.

By R. E. SOMEES.

Most of the clays considered in this report were examined microscopically in order to determine the minerals they contained, and in 

addition thin 'sections of some of the burned samples were studied, 

so far as time would permit, in order to ascertain the changes that 

took place in burning.

This investigation is not to be regarded as exhaustive, for much 

work of this kind still remains to be done, but the results are believed 

to be of interest and are therefore here presented.

METHOD OF EXAMINATION.

The. samples examined were obtained by gently crushing the crude 

clay and mounting it in balsam dissolved in xylene. c The specimens 

were then allowed to stand 24 hours before they were studied, in 

order to permit the balsam to harden.

It was not considered necessary to use liquids of special indices 

of refraction* for most of the work, as the greatest value of the 

examination seems to be derived from a general study of the more 

common minerals rather than from a close determination of the 

rarer grains, and the minerals that are m,ost abundant have indices 

near that of balsam.

The following table shows the minerals that were noted in the. 

specimens examined and their approximate abundance. Most of the 

clays examined probably contain colloid matter that is not visible 

under an ordinary microscope. The minerals listed include only 

those that were identifiable. The following letters are used to indi- 

"cate relative abundance: S, scarce; C, common; M, moderate 

amounts; A, abundant; VA, very abundant.

Minerals in residual and sedimentary clays.

Residual clays.

Formation and locality.

GKANITE.

English china clay, washed.......

CAMBRIAN SANDSTONE (CHICKIES

QUARTZITE).

Frazor, Pa. .......................

292

«

d

&

S

A

8

a

2 o

W . t

M

M

3 3

w

VA

A

o3

3

tf

C

a

a

S3

d

1S'

o

<o

o

S

ft

W

09

§.

H

n

ai

M

«

<u

103 W

fe"S

S 

2'3 i

O
MICROSCOPIC STUDY- OF CLAYS. 293

Minerals in residual and sedimentary clays Continued. 

Residual clays Continued.

Formation and locality.

CAMBRIAN SCHIST.

Mount Holly Springs, Pa.:

Sandusky Portland CementCo.

Holly Clay Corporation,

Narvon. Pa.: 

Whittaker pit. ...............

Diller pit.. ...................

CAMBRIAN (CHICKIES) QUARTETTE.

CAMBRIAN (OATESBURQ) CLAYEY 

SANDSTONE.

Warriorsmark, Pa................

Furnace Road. Pa.: Colonial Clay 

Co..............................

CAMBRIAN SHALE.

CAMBRIAN LIMESTONE.

Lutesville, Mo.:

Clay No. 1..... ...............

ORISKANY GROUP (SHALES, LIMESTONES, AND SANDSTONES).

Kunkletown, Pa.: Disintegrated

Kunkletown, Pa.:

Clay with quartzite, washed. .

Saylorsburg. Pa.: 

CrudeNo. 1. .................

Crude No. 2..................

 Washed......................

Crude, Cement Co.'s mine. . . .

Shirleysburg, Pa. ................

MISCELLANEOUS.

Bauxite, Ark.: 

Banded clay under bauxite o.

White clay under bauxite o. . .

Oreana, Nev.: Pitt-Bowland deposit...........................

Lovelocks, Nev.: AdamsonDickson deposit ................

Beatty, Nov.: Bond-Marks deposit ...........................

Antioch, Calif. ...................

Fort Payne, Ala.:

Cochrane pit; bauxite ............

Bynum, Ala.:

a. 

§

c

c

A

C

C

M

C

S

A

VA

A

A

A

C

C

C

C

A

C

c

c

8

A '

A

S

C

S

Hydromica.

A

C

A

C

C

C

S

A

A

C

A?

s

S

s

»

c

c

c

A

A

C

C

S

s

6A

S

A

C

S

A

C

Kaolinite.

VA

A

A

A

VA

VA

A

A

S

C?

VA

A

A

S

A

A

A

A

A

VA

VA

A

A

S

VA

A

M

A

Kutile.

C

C

C

S

S

C

s

c

c

s

A

C

A

S

8

S

A

C

A

S

A

A

A

A

S

S

s

s

s

A

A

A

S

C

Zircon.

R

R

R

R

R

R

R

S

S

S

s 

S

S

Tourmaline.

S

S

S

s

c

s

s

s

s

s

s

s

s

s

s

s

s

s

Epidote.

S

s

s

s

s

s

s

Titanite.

S

C?

s

s

Diaspore. Halloysite.

VA

Colloid matter.

'

M?

A

VA

A

a Contains some large flakes of mica. 

* Probably mostly sericite.
294 ' HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

Minerals in residual and sedimentary clays^-Goutinned. 

Residual clays Continued.

Formation and locality.

CARBONIFEROUS ROCKS.

Cheltenham clay, St. Louis district, Mo.: 

La Cleae-Christy, raw washed

La Clede-Christy, weathered

La Clede-Christy, fire-brick

La Clede-Christy, selected

Highland Clay Co., weathered

Highland Clay Co., washed

Flint clay district, central Missouri:

Owensville, Mo. 

Sassmanpit, diasporeclay

Connell pit, diasporeclay. 

Connell pit, diaspore clay. 

Hofflin, Mo. 

Rosebud, Mo. 

Toelke & Heidel pit, flint

Brown pit, diaspore clay . 

Huron district, Ind.: 

Indianaite (earthy white clay) 

Indianaite (massive white

/>]Q-IT\

N

M

<§>

C 

C 

C

c

s 

c

A

S

Hydromica.

A 

A 

A 

A 

A 

A

C

S

C

s

s

A

S

Kaolinite.

A 

C 

S 

S 

A 

C

S

s 

s 

s

A 

A 

C 

A

VA 

C

C 

A 

C

Rutile.

S 

A 

S 

S 

S 

A

S

c 

c

A

S

s

s

s

A

A

S

s 

s 

c

Zircon.

S

S

s

s 

s

s

Tourmaline.

'

S

S

S

s

Epidote. S

S

R

|

S

Diaspore.

0

C

C

A

S

A 

VA

VA

Halloysite.

cC?

cA?

Colloid matter.

C 

C 

C

C

C

C?

Sedimentary clays.

LOWER CRETACEOUS JDEPOSITS.

Gordon, Ga.: 

Columbia Kaolin & Aluminum Co. .white clav of upper 

bed...............'..........

Columbia Kaolin & Aluminum Co., nodular clay of

Dry Branch, Ga.: 

American Clay Co., crude

American Clay Co., washed

UPPER CRETACEOUS DEPOSITS.

Allendale, S. C.: J. L. Box pit. ... 

Rayflin. S. C.: Bdisto Kaolin Co.. 

Abbeville. S. C: Hill pit. .........

Trenton, S. C: White clay. .......

Bath,S. C.: 

McNamee Kaolin Co., clay 

No.l... ....................

McNamee Kaolin Co., clay 

No.2... ....................

Do...........................

. Ripley formation. 

Perry, Ga.: Houston Kaolin Co.,

Houston Kaolin Co., white part of 

mottled clav. ...................

C

S

S

s

A

S 

A 

C

S 

8 

S

S

C

c 

c

s 

s 

c 

s

M

C 

C 

C

8

S

S

A

S

VA

A

A

A 

A 

VA

A

A 

VA 

A 

A

S 

S

S 

S

s 's

s 

c

s

A

A

A 

A 

A 

A

C

S

S

S

s 

s

s 

s

s

s 

s

s 

s

s

R

s

c

s

s

M 

VA

A

A

This mineral may be allophane and not halloysite.
MICROSCOPIC STUDY OF CLAYS. 295

Minerals in residual and sedimentary clays Continued. 

Sedimentary clays Continued.

Formation and locality.

UPPER CRETACEOUS DEPOSITS 

continued. 

Ripley formation Continued. 

Houston Kaolin Co., red part of

Hollow Rock, Tenn.:

Do.......................

Paris, Tenn.:

Porters Creek clay. 

Benton, Ky.:

Wilcox group. 

Andersonville, Ga.:

Sweetwater mine, mottled 

clav

Enid. Miss.:

Bramlett No. 21 pit. ...........

Holly Springs, Miss., stoneware

flftV

Lester, Ark.: 

Camden Coal & Clay Co.,

Camden Coal & Clay Co.,

Lagrange formation. 

La Grange, Tenn.:

McKenzie, Tenn.:

Henry, Tenn.: Scates-Reynolds

Whitiock, Tenn.: 

Handle No. 1 S. G. P. clay....

Puryear, Tenn.: Dixie Brick & 

Tile Co. ........................

Hazel, Ky.: 

Cooley Ball & Sagger Clay Co., 

'wao. clay

Cooley Ball & s'agger Clay Co.,

Pryorsburg. Ky.: 

Kentucky Construction & 

Improvement Co., No. 4

Do.......................

Kentucky Construction & 

Improvement Co., No. 5

Mayfleld Clay Co., No. 3 ball

Hickory, Ky.: Old. Hickory Clay

TERTIARY DEPOSITS.

Edgar, Fla.:

Quartz.

S

C

C

 s

C

0

p

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C

r,

s

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A

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S

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Hydromica.

S

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Kaolinite.

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C

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Rutile.

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M

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8

Zircon.

8

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Tourmaline .

S

S .

S

s

s

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 s

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Epidote.

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Titanite.

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O

.

Halloysite.

"

Colloid matter.

<JA

Stained with hematite.
296 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES. 

IDENTIFICATION AND CHARACTER OF MINERALS.

QUARTZ.

If it occurs in medium-sized or .large grains, quartz can readily 

be discriminated by its index of refraction, low interference color, 

and lack of cleavage, for in such grains it resembles no other mineral 

found in clays. If, however, it occurs in small grains, it greatly 

resembles kaolinite. Its index of refraction is then of little assistance, the interference color is lowered nearly to that of the kaolinite, 

and it must be identified by its more angular shape and its more 

rapid extinction or " quicker wink." Such grains are generally 'so 

small that the difference in optical character is useless for their 

identification.

Quartz was noted in many of the clays examined and was particularly abundant in the residual clays. Most of the Wilcox clays 

from the embayment area contained but little quartz.

KAOLINITE.

Kaolinite can be distinguished by its orthodox characters where 

the particles are large and by its flaky appearance and its common 

tendency to combine in fan or worm-shaped bunches. (See PI. 

XXVII, A.) Its low index of refraction and low birefringence 

distinguish it from the other micaceous minerals. Where it is fine, 

it can merely be noted as minute transparent plates, whose index 

of refraction is close to that of balsam, and whose interference color 

is very low.

Kaolinite occurs in the clays examined as single scales or plates, 

some of them in fan-shaped bunches, and also as vermiculites. In 

one clay, the indianaite from Lawrence County, Ind., spherulite-like 

bodies were also found, but these are rare. Especially fine examples 

of " fans" were noted in the clay from Perry, Ga.; Bynum, Ala.; 

Bauxite, Ark.; and Antioch, Calif. Good examples of vermiculites 

were seen in the clay from South Carolina; Perry, Ga.; Bauxite, 

Ark.; Antioch, Calif.; and the nodular white clay from Gordon, Ga.

The clay from Okahumpka and Edgar, Fla., as well as that from 

Langley and Aiken, S. C., contained large single flakes of kaolinite. 

Many clays that contain considerable kaolinite show but few of the 

fans.

HYDROMICA. 14

Hydromica is a distinctly micaceous mineral whose single and 

double refractions are higher than those of kaolinite, yet not so high

84 Galpin, S. L., Studies of flint clays and their associates: Am. Ceramic Soc. Trans., 

vol. 14, pp. 306, 338, 1912.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXVH

A. "WORM" OF KAOLINITE, FROM BAUXITE, ARK. 

Ordinary light. X 405.

B. GRAIN OF TOURMALINE SURROUNDED BY GRAINS OF 

KAOLINITE AND HYDROMICA, FROM NARVON, PA.

Ordinary light. X 180.

PHOTOMICROGRAPHS OF SPECIMENSIOF.CLAY.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXVIII

A. OOLITE OF DIASPORE FROM FLINT CLAY AT ROSEBUD, MO. 

Ordinary light. X 97.

S. SPHERULITE OF KAOLINITE (P) IN WHITE CLAY FROM 

HURON, IND.

Polarized light. X 110.

PHOTOMICROGRAPHS OF SPECIMENS OF CLAY.
MICROSCOPIC STUDY OF CLAYS. 297

as those of muscovite or sericite. Furthermore, the degree of these 

refractions differs in different clays. It is therefore assumed that 

there is an isomorphous gradation between sericite and kaolinite, 

which is marked by a gradual loss of potash and addition of water, 

and in products of weathering, such as these, hydromica represents 

a transition stage of weathering toward kaolinite as the final product. 

The fan of the hydromica is similar to that of the kaolinite, but 

the grains of hydromica may be larger. Radiating bunches and 

spherulite-like grains were found in the white clay from the vicinity 

of Huron, Ind. (PI. XXVIII, #), but in none of the other clays 

examined. A clay that shows considerable sericite of relatively 

coarse grr. : n is that from the Pitt-Rowland deposit at Oreana, Nev. 

(PI. XXIX, A.)

COMPARATIVE ABUNDANCE OF KAOLINITE AND HYDBOMICAS.

In the reports on microscopic examinations of clays that have been 

published from time to time frequent reference is made to kaolinite, 

but the presence of mica is less often mentioned, yet the clays described in this report contain abundant mica.

The same inference might possibly be made from the chemical 

composition of many kaolins that show a small percentage of potash, 

for as feldspar seems to be very scarce the. potash is probably contained in mica. Vogt, for example, in 1906, concluded that china clay 

consisted of kaolinite, muscovite, and quartz, although he based his 

conclusions on the chemical composition of the material.35

Later Hickling,38 after studying the china clay of Cornwall, says 

that the finest washed clays contain kaolinite, mica, quartz, and 

tourmaline, but that kaolinite and mica make up 90 per cent of the 

mass. He adds, however, that the relative amounts of kaolinite and 

muscovite are difficult to estimate. He differentiates the mica into 

two classes primary mica and secondary mica derived from feldspar.

According to Hickling the kaolinite occurs in irregularly hexagonal 

prisms, with rough faces, which show strong transverse striations 

that correspond to the basal cleavage. Most of these prisms are 

curved and some of them are vermiculiform. The shorter prisms 

commonly present a fanlike arrangement and resemble the similar 

forms of mica so closely that they can be distinguished only by their 

lower interference tint. 'Isolated plates or very short prisms may

38 Vogt, G., De la composition des argiles: M^moires publics par la Soci6t6 d'encouragement pour 1'lndustrie nationals, Paris, pp. 193-218, 1906.

M Hickling, G., China clay; its nature and origin: Inst. Min. Eng. [England] Trans., 

vol. 36. 1908-9.
298 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

occur, and then, even with convergent polarized light, it is not easy 

sto judge the amount of birefringence and consequently to decide to 

which mineral a given fragment belongs; hence the difficulty of estimating the relative proportions of kaolinite and mica. Both minerals 

show the same irregular form (due probably to development within 

decaying feldspar) and the same evidence of corrosion on the edges.

The low interference tint and low index of refraction definitely 

distinguish these crystals from mica. The identification of kaolinite 

rests on the following evidence: (1) The index of birefringence is 

distinctly low, nearly that of quartz but variable; (2) the index 

of refraction is very near to 1.56; (3) the prismatic crystals extinguish parallel to the basal plane; (4) basal flakes show a biaxial 

interference figure.

Hickling refers to the mica as muscovite, but he notes that it may 

be hydrated. Indeed, he thinks that the muscovite changes directly 

to kaolinite in the clay, because he can find mica but no kaolinite 

in the feldspar or in the granite, because there is no difference in form 

between the mica and the kaolinite,' and because some prisms are 

composed of mica at one end and kaolinite at the other.

Hickling also quotes the observations of Johnstone,37 who found 

that after muscovite had been immersed in pure water and water 

saturated with carbon dioxide for twelve months, it had changed to 

hydromuscovite. This experiment, Hickling believes, shows a conversion in the direction of kaolinite.

In his work on flint clays Galpin 38 found platy masses of a 

mineral which at first appeared to be kaolinite. These masses commonly show " ribs " or plates of higher index and birefringence 

intergrown with those of kaolinite, and these ribs show practically 

every grade of variation between kaolinite and muscovite.

HALLOYSITE.

Two clays those from the deposit north of Huron, Ind., and 

those from the Bond-Marks deposit, near Beatty, Nev. (PL 

XXX, A) contain isotropic material in platelike grains, which 

is probably halloysite. In no other samples could this material be 

so definitely identified.

BUTTLE.

In view of the probable constant occurrence of titanium in highgrade clays the presence of rutile is interesting. Practically every

87 Johnstone, A., On the action of pure water and of water saturated with carbonicacid gas on minerals of the mica family: Geol. Soc. London Quart. Jour., vol. 45, p. 363, 

1889.

88 Galpin, S. L., Studies of flint clays and their associates: Am. Ceramic Soc. Trans., 

vol. 14, p. 301, 1912.
MICKOSCOPIC STUDY OF CLAYS. 299

clay examined contained some rutile. In some clays it occurs in 

grains or prisms, perhaps 0.015 to 0.020 millimeter in diameter, and 

in these its color and refractive properties distinguish it at once. 

Generally, however, it is found on close examination as very minute 

grains or needles, which are nevertheless so clear-cut that their 

refractions can be plainly seen. The interference color is of the 

first order, but the particles are so small that the actual birefringence 

is thereby shown to be very high. They range from perhaps 0.001 

to 0.010 millimeter in diameter, and the length of the needles is five 

or six times their width. Though these grains are numerous, their 

actual bulk represents a very small quantity of rutile.

BABE MINEBALS.

Tourmaline is well marked by its pleochroism, and its common 

occurrence is notable. (See PL XXVII, B.) Epidote appears in 

some specimens as a slightly greenish mineral of moderate single and 

'double refractions. Grains of zircon and titanite, marked by high 

index and birefringence, are common though not abundant: A distinction between the two is possible by means of the higher interference color of the titanite. Zircon is much the commoner.

DIASPOBE.

Diaspore is easy to determine by its moderately high index and 

double refraction and its occurrence in irregular grains. It is common in some of the clays examined from Missouri. (See PI. 

XXVIII, A.) Some of the diaspore in these clays or their associated 

rocks occurs in grains sufficiently large to be seen with the naked eye 

and thus may be mistaken for quartz, but the diaspore can be separated from the quartz and the clay by means of bromoform (specific 

gravity 2.8), in which the diaspore (specific gravity 3.4) sinks and 

the associated minerals float.39 The section of a diaspore oolite from 

the flint clay at Rosebud, Mo., shows the concentric shells composing the grains.

GIBBSITE.

Gibbsite has been noted by Galpin 40 in the flint clays from Olive 

Hill. Ky., where it occurs in minute oolites similar to the diaspore in 

the flint clays from Missouri.

89 Wherry, E. T., Field identification of diaspore: Am. Mineralogist, vol. 3, p. 154, 1918. 

*° Galpin, S. L., Studies of flint clays and their associates: Am. Ceramic Soc. Trans.. 

vol. 14, p. 301, 1912.

77412 22 22
300 HIGH-GRADE CLAYS OF' THE EASTERN UNITED STATES.

TEXTURE.

No attempt is made in this bulletin to standardize the clays according to size of particle because any clay is apt to be made up of particles of all sizes and because there is no standard to use. However, in 

the clays examined relatively coarse grains average 0.100 millimeter 

or more in size, medium grains 0.020 to 0.025 millimeter, and fine 

grains 0.010 millimeter or less.

MINERALS IN THE BURNED CLAY.

A number of samples of the clays were molded into 1-inch cubes, 

which were all fired for 8 hours to 950° G. After this firing one set 

of the cubes was refired for 8 hours to 1,150° C., and a second set was 

refired for 10 hours to 1,300° C. The cubes were then ground to thin 

sections and studied under the microscope. (See Pis. XXIX, B; 

XXX, B.)

Grains of quartz as a rule stand out with much greater clearness in 

the burned than in the raw clay, for the hydrous aluminum silicates 

tend to mat or fuse together to a fine-grained groundmass, which 

holds the quartz. In some specimens a fluxing action appears to have 

taken place between the fine-grained material and the silica, which 

has resulted in corrosion of the quartz, but this condition is comparatively rare in the specimens studied. Plate XXIX, #, shows a thin 

section of kaolin from Mount Holly Springs. Pa., which was fired at 

1,150° C. In this section the corroded'quartz grains are clearly seen in 

the groundmass of mostly isotropic character. On heating to 1,150° 

C. hydromica either practically disappears, forming an isotropic 

mass (PL XXIX, Z?), or else it loses the greater part of its interference color. The only exception to this condition. occurred in 

samples where the grains of hydromica were much larger than usual,

and then the central portion of the grains retained usually the original interference color (PI. XXIX, A).

This change of the hydromica on heating suggests that it furnishes 

some of the flux for the clay, and other things being equal there may 

be a connection between the degree of density at the temperature mentioned and the quantity of hydromica present.

If it is not fluxed, kaolinite appears to retain its shape and at least 

a part of its original interference color. Tourmaline and probably 

epidote disappear even at 1,150° C., but rutile, zircon, and probably 

titanite seem to be unaffected even at 1,300° C. The persistence of 

the rutile can be plainly seen even though the particles are very small.

Sillimanite was noticed in a white clay from Florida that was fired 

at 1,150° C. where the conditions happened to be just right for its development. (See PL XXX, B.) That it has formed from the large 

flakes of kaolinite or the low-grade hydromica is clearly indicated by 

one composite flake of the two minerals.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXIX

A. CLAY FROM PITT-ROWLAND MINE, OREANA, NEV.

Section cut from a specimen of coarse-grained quartzose and sericitic clay 

fired at 1,150* C. The structure in the section is due to to numerous grains 

of sericite that show interference colors of kaolinite. Crossed nicols. 

X 110.

B. KAOLIN FROM MOUNT HOLLY SPRINGS, PA.

Section cut from a specimen fired at 1,150° C. The groundmass is mostly 

isotropic, with a few scales of kaolinite and grains of quartz that show 

corrosion. X 51.

PHOTOMICROGRAPHS OF SPECIMENS OF CLAY.
U. S. GEOLOGICAL SURVEY BULLETIN 708 PLATE XXX

A. RESIDUAL CLAY FROM BEATTY, NEV. 

Shows scales of halloysite (?). X 110.

S. BURNED WHITE SEDIMENTARY CLAY FROM FLORIDA.

Section cut from a specimen fired at 1,150° C. The groundmass is mostly 

isotropic but shows a few grains of quartz and needles of sillimanite. 

Crossed nicols. X 110.

PHOTOMICROGRAPHS OF SPECIMENS OF CLAY.
MICROSCOPIC STUDY OF CLAYS. ' 301

The actual cause of its development is not evident, for other clays 

that contain similar micaceous flakes and that were burned at the 

same time do not show the sillimanite in the burned product.

This development of sillimanite by burning and its possible abundance in porcelain 41 may serve to explain a feature that was noted 

in some of the other clays, when a double refraction was produced in 

the groundmass of these clays by burning to higher temperatures. 

This double refraction is very probably caused by particles too minute 

to be easily recognizable, and the development of the interference 

color may be due to the formation of sillimanite. The single and 

double refractions of the material would not be evidence against this 

supposition, and the only evidence for it is that of analogy.

In the sections where sillimanite was actually determined it is present in the form of slender crystals, of fair size and can be distinguished with certainty by its moderate relief, low interference, optical character, and cross fractures.

The following table gives a summary of the features shown by a 

number of the thin sections. These features are worth recording, although.the series is not sufficiently large to warrant definite conclusions. For further comparison the table also gives the texture of the 

clay, the relative abundance of the chief constituents, and the porosity 

after burning.

41 Klein, A. A., The constitution and micrtistructure of porcelain: Am. Ceramic Soc. 

Trans., vol. 18, p. 377, 1916.
302 HIGH-GRADE CLAYS OF THE EASTERN UNITED STATES.

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Tenn.

White granular sedimentary 

clay from Andersonville, 

Ga.

Clay from Ben ton, Ky........

Clay from Enid, Miss. .........

Clay from Holly Springs, Miss. .

Clay from mine of Mayfleld 

Clay Co., Pryorsburg, Ky.

White clay from Dry Branch, 

Oa. 

Washed white clay from 

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Medium... ^, ,

Medium to 

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Medium. .

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Fine. .........

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PI. XXX, 
'304 HIGH-GRADE CLAYS OP THE EASTERN UNITED STATES. 

PREVIOUS WORK ON BURNED CLAY.

Microscopic studies of burned-clay wares, chiefly porcelains, have 

been made by a number of investigators, but much less of this work 

has been done on the clays alone.

After heating a refractory clay at white heat for 72 hours, Vernadsky 42 observed the presence of small crystallites, which were 

optically positive and showed an extinction parallel to the prismatic 

axis. They were insoluble in cold concentrated hydrofluoric acid.

After studying the changes in clay on heating, Glasenapp 43 came 

to the conclusion that all clays dissociate at a sufficiently high temperature into a glassy groundmass and a crystalline portion and that 

their disassociation increases with increasing temperature and duration of burning. He considered the glassy groundmass to be richer 

in silica and the crystalline material to be richer in alumina.

Klein 44 experimented with samples of kaolin from North Carolina and from England. The sample from North Carolina showed 

kaolinitic material as its chief constituent and also much xsericite. 

The sample from England was similar but showed more sericitic 

mica.

Both samples were heated for five hours at 600°, and for two 

hours each at 900°, 1,100°, 1,200°, 1,300°, 1,400°, 1,450°, and 1,500° 

C. Klein reports the results of his microscopic examination after 

each of these burns as follows:

As soon as the water of combination was driven off, the kaolinitic material 

became entirely isotropic, but the index of refraction altered to only a slight 

extent. Then there was no profound change noted in the optical properties 

until the temperature of burning reached upward of 1,200°. At this point 

there was. noted a beginning of an incipient dissociation of the kaolinitic 

material, which became manifest by the formation in very small amounts of 

two isotropic substances, one of which had an index lower than 1.50 and the 

other had an index higher than 1.60. They were extremely intergrown and 

showed no attempt toward crystal form.

The dissociation remained incipient until a burning temperature of 1,400° 

was reached, when a complete dissociation occurred and the two isotropic 

compounds noted above were formed. The higher refracting isotropic material 

showed no crystalline development but occurred as extremely minute, almost 

submicroscopic, irregular to rounded grains, intimately intergrown with the 

lower refracting product of dissociation.

There were also a few aggregates of thin prismatic crystals, which 

were apparently isotropic and of greater index than 1.60.

Between 1,400° and 1,450° C. nearly all the higher refractory 

isotropic grains showed a prismatic development, an index of about 

1.64, biaxial interference figures, and an optically positive character.

*2 Vernadsky, W., Soc. franc,, minfiralogie Bull., vol. 13, p. 256, 1890.

*3 Glasenapp, M., Ueber Aenderungen der Mikrostruktur der Tone durch Einwirkung 

holier Hitzegrade: Tonindustrie Zeitung, vol. 31, p. 1167, 1907.

** Klein, A. A., The constitution and microstructure of porcelain: Am. Ceramic Soc. 

Trans., vol. 18, p. 377, 1916.
MICROSCOPIC STUDY OF CLAYS. 305

These grains were thought to be sillimanite, and Klein believes 

that the higher refracting amorphous material previously mentioned 

is an amorphous phase of sillimjanite, which resulted from the dissociation of the kaolinite molecule "before there is sufficient mobility for molecular orientation in any definite crystalline form."

Even in burning mixtures of clay, quartz, and feldspar the needles 

of sillimanite occurred only to a very slight extent between 1,250° 

and 1,275° C. and below this temperature not at all. 

. In comjmenting on Klein's results, Mellor tt claims that crystals of 

sillimanite can develop abundantly in bodies which have not reached 

1,200° C., and he considers the time factor an important conditioning 

variable. In other words, in an extended period of time work can 

be done which could also be done at a higher temperature in a 

shorter period of time.

Mellor also states that there is evidence to show that the crystals 

develop much more freely in some mixtures than in others which 

contain the same constituents in different proportions and compounded in different ways.

The results obtained by Klein do not agree with those reached by 

the writer, for in the specimens studied by the writer the hydromica 

became isotropic at as low a temperature as 1,150° C., but the kaolinite did not.

The writer's results are, however, somewhat in agreement with 

Klein's, so far as the slight formation of sillimanite is concerned. ~

48 Mellor, J. W., Can the firing temperature of a body be determined from the microscopic appearance?: Eng. Ceramic Soc. Trans., vol. 16, pt. 1, p. 71, 1917.

INDEX.

A.

Page.

Abboville, S. C., clay deposits near_ 79-

82,230-233 

Ackerman formation, clays of, In

Mississippi__ ____ 240 

Acknowledgments for aid______ 1 

Adamson-Dlckson property, east of 

. Lovelocks, Nev., clay

on___________ 122-124 

clay from, changes in, from

burning_________ 302

Aiken, S. C., geologic section near_ -165-166

Middendorf arkose clay near. 220-221

Alabama, clay of Selma chalk in__ 222-223

kaolins from pegmatites in___ 82

residual clay deposits in__ 128-131

Tuscaloosa clays in__ __ 204-205

Alexandrian Fire Clay Co., pit of, at

Petersburg, Pa____ 115 

Alleghany Ore & Iron Co.'s mine,

Lignite, Va., clay in_ 117-120 

Almond, N. C., kaolin mine near_ _ 44 

American China Clay Co., mine of,

. near Lutesville, Mo_ 107-108 

American Clay Co., pit of, near Wickliffe, Ky_________ 282

Analyses of ball clays 9

Analyses of clays from Alabamal 129

from Connecticut-- - _ 99

from Kentucky_____ ____ 281

from Mississippi 246

from Missouri__________ 136,139

from North Carolina__- _ 23, 24,

25, 50, 54, 69, 73

from South Carolina 81. 

168,178,186,231

from Tennessee 271, 272

from Virginia____ 101,103,118

Analyses of indianaite-___ 150,151,157

kaolins _ 7

white sedimentary clays 8

Analysis of limonite from Lawrence

County, Ind 153 

Andersonville, Ga., clay deposit

near__________ 234-235 

white clay from, changes in,

from burning _ 303 

Antioch, Calif., clay deposit near 126 

Arkansas, clays of the Wilcox group

in ___________ 255-259 

kaolin deposits in _____ 120-121 

Atlantic Coastal Plain, sedimentary

clays of_______ 162-291 

Atlas Portland Cement Co., clay mine 

of, near Saylorsburg, 

Pa_______-__ 113

13.

Page. 

Bailey Lumber Co., property of, near

Penland, N. C_____ 47-51 

Bakersville, N. C., kaolin deposit

near ____________ 63-64 

Ball clay, importation of_______ 3, 4-5 

production of ___________ 6 

properties of____________ 9 

Bare, Jessc, sr., property of, near Jefferson, N. C______ 64 

Bath, S. C., clay deposit near___ 168-171 

Bauers & Watkins, clay pit of, near

Rosebud, Mo_____ 144 

clay pit of, plate showing.___ 144 

Bausch, F. B., kaolin mine of, near

Lutesville, Mo____ 108 

Bauxite, Ark., kaolin deposit at__ 120 

Beatty, Ncv., clay deposits near_ 124-126 

kaolin from, effects of burning on ______ 302 

photomicrograph of __ 301 

Beavertown, Pa., kaolin deposits

1 near _______ _ 88-89 

Belle, Mo., clay pits near __ 147 

Benore, Pa., kaolin deposit near__ 94 95 

Benton, Ark., clay beds near_____ 259 

Benton, Ky., clay pits near___ 236-237 

clay from, effects of burning on_ 303 

Beryl, products of weathering of 21, 27 

Bessemer City, N. C., kaolin deposit

near__ _ ____ 65-67 

Beta, N. C., undeveloped kaolin deposit near____ _ 55-57 

Biotite, products of weathering of_ 21, 27 

Birdtown, N. C., kaolin deposit near. 59-60 

Black Creek formation, clay deposits in __ 211-222 

Blair property, Stormstawn, Pa.,

description of__ 94-95

Bland, Mo., clay deposits near 145-146

Bleininger, A. V., acknowledgment to_ 1

and Loomls, G. A., cited_____ 201'

Bond & Marks, clay deposit of, near

Beatty, Nev__ 125-126 

Bosticks Mills, N. C., kaolin deposit near_ __ __ 72-75 

Brackett, R. N., analyses by 81 

Bramlett, J. T., clay pit of, near

Enid, Miss_____ 243-245 

clay pit of, plate showing 238 

Branner, J. C., cited -__ 255 

Brick clay, production of 6 

Briensburg, Ky., clay deposit near- 238 

Brown, Charles, clay pit of, near

Rosebud, Mo ____ 144

307 .
308 INDEX.

Page. 

Brown, G. H., uses of the clays of

New Jersey______ 203-204 

Bryson, N. C., analyses of kaolin

from ___-____ 25 

kaolin mines near________ 44-47 

Budding & Co., J. C., clay in quarry

of____________ 91 

Buena Vista, Va., kaolin, deposit

near__________ _ 104

Burned clay, minerals in______ 300-303

previous work on_______ 304-305 

Butler, Ga., clay plant at______ 199 

Buwalda, J. P., kaolins in Nevada__ 121-126 

Bynum, Ala., clay deposit near__ 130-131

C.

' Cacapon Forks, W. Va., kaolin deposit near_______ 117

California, clay deposit in_ 126

Cambrian limestone, in Missouri,

kaolins from____ 104-108 

minerals in clays of 293

Cambrian quartzite, kaolin from, in

central Pennsylvania. 92-99 

residual clay from, plate showing. _ 87

Cambrian sandstone, minerals in

clays of______ 292,293

Cambrian schist, minerals in clays

of_____________ 293

Cambrian shale, in Virginia, kaolin

from___________ 99-104 

minerals in clays of__ 293

Camden Coal & Clay Co., clay in 

mine of, near Lester, 

Ark_______^__ 25C-259

Campbell & Lichte, clay pit of, near

Bland, Mo______ 145-146

Canaan, Mo., clay deposits near 146-147

Carboniferous clays, localities of 131-135 

minerals in__l . 294

Carrollton, Miss., clay deposit at__ 250-252

Cashion & Furchess, property of,

near Statesville, N. C 71-72

Castlebury, John, clay bed of, near

luka, Miss___ 206-208

Catawba, N. C., kaolin deposit near. 70

Charleston, Miss., clay deposits

near ________ 248, 250

Cheltenham fire clay, nature and occurrence of____ 131-133

Chickies quartzite, minerals in

clays of_______ 292,293

China clay. See Kaolin.

Claymont, Ga., clay plant at 198

Clay Products Co., pit of, near Toecane, N. C 36

Cloth, use of sedimentary clays for

filling '- __ 190

Coker, T. H., jr., clay property of,

near Society Hill, S. C- 222

Cold Spring, Va., kaolin deposit

near_________ 101-102

Cole & Black property, near Birdtown, N. C., description of_______ 59-60

Page.

Colonial Clay Co., kaolin deposit of, 

near Furnace Road, 

Pa____________ 95-96 

pit of, near Hickory Grove, Ky_ 281

Columbia Kaolin & Aluminum Co., 

clay bank of, near 

Gordon, Ga., plates 

showing ____;___ 196 

operations of __ _____ ^198

Columbia Mineral Products Co., pit 

of, near Horrell Hill, 

S. C__-_______ 219-220

Connecticut, kaolin from feldspathic

quartzite in ______ 99

Connell, J. P., clay pit of, near

Owensville, Mo____ 141-142

Consolidated Mining Co., bauxite 

mine of, near Fort 

Payne, Ala., clay in__ 129

Cooley Ball & Sagger Clay Co., pits 

of, northwest of Puryear, Tenn_____ 272-275 

pits of, plate showing______ 264

Cooper, H. N., clay pit of, near

Hollow Rock, Tenn_ 227-229

Cox, Dr., clay pit of, near Hofflln,

Mo___________ 140-J.41 

clay pit of, plate showing_ 103

Cox, E. T., cited_______:_____ 159

Cox & Sassman, clay pits near 

Canaan, Mo., worked 

by_____________ 147

Cretaceous deposits, minerals in

clays of________ 294-295

Crevi, Miss., clay beds near____ 246, 247

Cumberland Clay Co., kaolin deposit of, near Upper 

Mill, Pa_________ 85

Cunningham property, near Franklin, N. C., description of__________ 42-43

D.

Dale, J. F., clay in sand pit of, near

La Grange, Tenn ' 262-263 

sand pit of, plate showing- 262

Dean, Pa., clay from________ 135

Delaware, kaolin pits in __ 18

Diaspore, microscopic determination

of ___ _____ 299

Diller Clay Co., pit of, near Narvon, Pa_________ 90-91

Dillsboro, N. C., analyses of kaolins

from____________ 23 

clay pits near________ 28-31 

undeveloped kaolin deposits

near _ _ 55

Dixiana, S. C., clay deposit at 185

Dixie Brick & Tile Co., clay pit of,

near Puryear, Tenn 272

Dry Branch, Ga., clay pits near 198,199 

white clay from, effects of burning on _____'____ 303

Dungarvin station, Pa., kaolin, deposits near ____ 97-98
INDEX. 309

Page.

E.

Eames, P. M., property of, near 

Mount Gilead, N. C., 

description of______ 69 

Eastport, Miss., Tuscaloosa clay

near __________ 209-211 

Edgar Bros. Co., operations of- 198 

pit of, near Mclntyre, Ga., plate

showing._______-.- 198 

Edgar Plastic Kaolin Co., operation^

of________ _ 290 

pit of, plate showing__ 278 

Edisto Kaolin Co., pit of, near Rayflin, S. C____.__ 213-215 

Eifert, Ohio, clay shipped from 134 

Ellerbe, N. C., kaolin deposit near 72-75 

England, importations from__ 2, 3, 4, 5 

Enid, Miss., clay deposit west of__ 243-248 

clay from, effects of burning on_ 303 

Eocene (?) clay in South Carolina,

locality of______ 230-233 

Epidote, microscopic determination

of____________ 299 

Ervin, E. A., property of, near Catawba, N. C., description of_________ 70 

Etowach, N. C., kaolin deposit near. 57-58 

Eutaw formation, clay in 222 

Exports of clay _ _ 5-6

F.

Federal Clay Products Co., clay mine < of, at Mineral City, 

Ohio___________ 134

Feldspar, results of weathering of _ 20

Feldspathic quartzite in Connecticut,

kaolin from_______ 99

Ferguson property, near Franklin,

N. C., description of _ 54-55

Field work, record of- - 1

Fire clay, exports of____ 5 

production of _ -. 6

Firescald property, near Penland,

N. C., description of__ 50-51

Florida, OHgocene clays in____ 289-291 

white sedimentary clay from,

effects of burning on_ 303 

photomicrograph of 301

Flukin Ridge kaolin deposit, near 

Bakersville, N. C., description of_______ 63-64

Fort Payne, Ala., clay deposits

near__________ 128-129

Franklin, N. C., analysis of kaolin

from_____- _______ 25

kaolin mines near____ 41-44 

undeveloped kaolin deposits

near___________ 52-55

Franklin Kaolin & Mica Co., lotla

mine of_________ 43-44

French Clay Blending Co., pit of,

near Charleston, Miss_ 248

Furnace Road, Pa., kaolin deposit

near ___________ 95-96

Page.

Gants mine, shaft house and storage 

shed of, near Mountain 

Glen, 111., plate showing ____________ 279 

Garnet, products of weathering of 21, 27 

Geiger, Mrs. Lizzie B., clay property

of, near Dixiana, S. C_ 185 

Georgia, clay of Wilcox group in_ 234, 239 

clays of the Midway group in_ 233-235 

clays of the Ripley formation

in ___________ 224-225 

kaolin from pegmatite in____ 82 

Lower Cretaceous clays in, distribution and occurrence of____ 194-196,198 

nature of_^ 196-198 

tests of__" _ __ 199 

utilization of__ 198-199,200-201 

map of part of 194 

Georgia Kaolin Co., pit of, plate

showing 197 

Germany, importation from___ 2, 3, 4, 5 

Gibbons, S. B., clay deposit of, near

Hudsonville, Miss _ 252-253 

Gibbsite, microscopic determination

of____________ 299 

Glen Lock, Pa., kaolin deposit near. 82-83 

Golden, Miss., Tuscaloosa clay near. 209 

Golding Sons Co., tests of clay from 

pit of, near Butler, 

Ga_____ 199 

Goode property, Lipscomb, Va., tests

of clay from__ __ 100 

Gordon, Ga., clay plants at_____ 198 

Granite, kaolin from_________ 65-68 

kaolin from, minerals in__ __ 292 

Grenada formation, clays of, in Mississippi ________ 242-252 

Gross Almerode clay, American clays

resembling _^___ 258, 282 

importation of _ 2, 3 

Gurney mine. See Porter property.

H.

I-Ialloysite, microscopic identification

of_____________ 298 

" Hamburg beds," position of _ 165,166 

Hand Clay Co. (Inc.), kaolin mine

of___________ 31-34 

kaolin mine of, panoramic view

of_____________ 32 

I-Iarbison-Walker Refractories Co.,

clay mine of, at

Spencer Hollow, Ohio_

133-134

Harris Kaolin Co., clay mines of_ 28-31, 

36-41, 46-47, 48-50 

kaolin deposits of__ 55, 60, 62-63 

Haynes, S., clay pit of, near

Canaan, Mo 146 

Hazelwood, N. C., kaolin deposit

near___;____ _ 58-59 

Heidel & Toelke, clay pits of, near

Rosebud, Mo_____ 144-145
310 INDEX.

Page. 

Henderson Bros., clay property of,

near Aiken, S. C__ 220-221 

Henry, Tenn., clay deposits near_ 267-269 

Henry Clay, Pa., kaolin deposit near- 86 

Herren property, near Hazelwaod,

N. C., description of 58-59 

Hewitt mine, near Almond, N. C., description of ____ 44 

Hice, E. R., acknowledgment to___ 1 

Hickory Grove, Ky., clay deposits

near _________ 280-282 

Hill, J. A. and W. E., clay property

of, near Abbeville, S. C.

80-82, 230-233

Hofflin, Mo., clay deposit near__ 140-141 

Hog Ro.ck mine, Dillsboro, N. C.,

description of ___._ 28-30 

Hollidaysburg, Pa., clay deposit at_ 116 

Hollow Rock, Tenn., clay pits near_

225-229 

sagger clay from, effects of

burning ^on_______ 303 

Holly Clay Corporatio'n, digging antl

washing of kaolin by- 86-88 

pit of, plate showing ____ 86 

Holly Springs, Miss., clay deposit

near _________ 241-242 

clay from, effects of burning on_ 303 

Holly Springs sand, clays of, in Mississippi . 240-242, 252-255 

Honeybrook, Pa., kaolin deposit near- 91 

Hornblende, products of weathering

^ of____________ 21 

Horrell Hill, S. C., Middendorf arkose clay near __ _ 215-220 

Houston Kaolin Co., pit of, near

Perry, Ga_______ 224-225 

Hudsonvllle, Miss., clay deposit

near ______ ___ 252-253 

Huefner, Pa., clay from________ 135 

Huron, Ind., deposit of indianalte

near, structure of__ 154-150

Hydromica, change in, from firing__ 300

comparative abundance of__ 297-298

microscopic identification of_ 296-297

I.

Idaho, clay deposits in ______ 126

Illinois, clays of Wilcox (?) age in_

284-289

Porters Creek clay in 236 

Illinois Kaolin. Co., old pit of, plate

showing_________ 279 

 pit of, near Mountain Glen,

111___________ 284-285 

Immaculate Kaolin Co., property of,

near Langley, S. C 182-184 

Imports of clay, quantities of- 1-3 

sources and kinds of 3-5 

India, Tenn., clay pits near_ 229 

Indiana, indianaite deposits in_ 147-162 

Indianatte, deposit of, near Huron,

Ind__________ 154-157 

distribution of-___ __ 147-149 

geology of 149-150

Indianaite, nature of__ 150-152, 156-157 

origin of_______________ 159-162

petrographic character of__ 156-157 

physical character of______ 156 

plate showing___________ 145 

relations of, to associated

rocks_________ 158-159 

resources of ____________ 154 

rocks associated with____ 152-154 

Interment China Clay Co, mine of_ 36 

Interstate Clay Co., property of, 

near Horrell Hill, 

S. C_________ 215-219 

lola gold mine, near Overton, N. C.,

kaolin deposit at_ 69-70 

lotla mine, near Franklin, N. C.,

description of_____ 43-44

Iron, removal of____________ 23

staining with_________ 21, 27, 33

luka, Miss., Tuscaloosa clays near_ 206-209

J.

Jefferson, N. C., kaolin deposit near- 64 

Job Thomas mine, description of-- 36 

Johnson-Porter Clay Co., pit of, near

Paris, Tenn_l____ 229-230 

pits of, near McKenzie, Tenn_ 264-266 

plates showing______ 264, 265 

Johnston property, near Franklin,

N. C., description of__ 42

K.

Kaolin, derivation of________ 16,16-17

distribution of _ _ 16

importation of _______ __ 2, 3

production of __________ 6

purest, position of_________ 21, 22

washing of-_ ____ 16

Kaolins, from pegmatites____-__ 17-82

properties of _ 7,15

Kaolinite, comparative abundance

of___________ 297-298 

microscopic identification of_ 296 

photomicrograph of grain of__ 296 

photomicrograph of " worm"

of_____________ 296 

Kaolinization, completeness of, in

depth __________ 22-23 

Kentucky, clays of the Lagrange

formation in_____ 276-283 

map of western part of 226 

Porters Creek clay in___: __ 236-238 

Kentucky Construction & Improvement Co., clay pits of, 

at Pryorsburg, Ky__ 277-279 

face of pit of, plate showing 278 

Keystone Clay & Reduction Co., mine 

of, at Saylorsburg, 

Pa_________ 111-112 

Kiernan property, near Beatty, Nev.,

clay deposit on 125 

Klein, A. A., cited_ 304 

Klingenberg clay, substitute for 203-204 

Kunkletown, Pa., clay deposit at 114-115
INDEX. 311

Page.

L.

La Clede-Christy Clay Co., pits of,

near Wickliffe, Ky..». 282 

Ladd, F. E., clay deposit of, near

Fort Payne, Ala__ 128-129 

" Lafayette" gravelly overburden, 

typical section of, plate 

showing_________ 239 

La Grange, Tenn., clay deposits

near __________ 262-263

Lagrange formation, clays of__ 259-289

clays of, plate showing_____ 23ft

minerals in____ ___ 295

columnar sections of, plate

showing___________ 260

Lamar, Miss., clay deposit near__ 253 

Langley, S. C., clay deposits near_ 171-184 

Lester, Ark., clay deposits near__ 256-259 

Lignite, Va., clay deposit at___ 117-120 

Llncolnton, N. C., kaolin deposit

near ________ _ 67-68

Linoleum clays, qualities of_ ___ 11 

Lipscomb, Va., kaolin deposits near,

100-101 

Little Rock, Ark., clay deposits near,

120-121

Lofton, Va., kaolin deposit at__ 102-103 

Logan, W. N., General features of 

the indianaite deposits

147-154

Loughlin, G. F., cited_________ 99 

Lovelocks, Nev., clay deposit southeast of________ 122-124 

Lowe, E. N., cited__________ 235-236 

undeveloped properties in Mississippi_______ 249-255 

undeveloped properties in Tish

omingo County, Miss. 206-231 

Lower Cretaceous clays, nature and

distribution of- 164-201 

.Lucinda, Pa., clay from___ _ 135 

Lutesville, Mo., kaolin from, effects

of burning on_____ 302 

kaolin mine near_______ 107-108 

shaft and hoisting drum at,

plate showing_____ 102

M.

Mabelvale, Ark., clay deposit near__ 120

McGuire property, near Franklin,

N. C., description of 53-54 

Mclntyre, Ga., clay pits near _ 198 

McKenzie, Tenn., clay deposits near,

264-267 

McLendon Clay Co., property of, near

Crevi, Miss________ 246

McNamee Kaolin Co., clay property

of, near Bath, S. C 168-171 

McNanee clay pit, near La Grange,

Tenn^ __ _ 263 

plate showing_ _ _ 262 

Handle Clay Mining Co., pits of, near

India, Tenn__ __ 229 I

pits of, near Whitlock, Tenn__ 269-271 I

plate showing_______ 265 >

Pago. 

Maryland, Arundel formation in,

clays of ___ __ 201 

kaolin pits in_____ _____ 18 

Patapsco formation in, clays of- 201 

Karitan formation in, clays of__ 204 

Mayfield Clay Co., clay from mine 

of, effects of burning 

On_____________ 303 

pit of, at Pryorsburg, Ky___ 279-280 

Mica, form of, in pegmatite _ 27 

removal of _ __ _ 24-25 

Micaville, N. C., analysis of kaolin

from ._.... __ 25 

kaolin deposits near___ 35-36, 60-61 

Microscopic study of clays 292 305 

Middendorf arkose member, clay deposits in___ ___ 211-222 

position of_______ 165,166,167 

Midway group, clays of__ _ 233-238 

Minis clay property, near Trenton,

S. C., description of- 185-186

Minerals, in burned clay _ 300-303

in residual clays.,_______ 292-294

in sedimentary clays. 294-295

microscopic identification of_ 296-299

Mining of kaolin, methods of 127-128

Mississippi, clays of the Midway

group in ___ __ 235-236 

clays of the Wilcox group in_ 239-255 

Tuscaloosa clays in, deposits in

Tishomingo County. 206-211 

distribution and nature

of ___________ 205-206 

Mississippi Embayment, sedimentary

clays of_______ 162-291 

Missouri, flint clays in, deposits

of ___________ 140-147 

flint clays in, nature of_____ 138-139

occurrence and distribution

of___________ 135-138 

kaolins from Cambrian limestone in___ __ 104-108 

Mitchell Clay Co., pits of, west of

Enid, Miss ____ 247 

Moore, E. S., acknowledgment to __ 1 

kaolin from Cambrian, quartzite 

in central Pennsylvania _____ ___ 92-99 

Mount Eaton Clay Co., mine of, near

Saylorsburg, Pa__ 112-113 

shaft of, plate showing. 86 

Mount Gilead, N. C., kaolin deposit

near___________ 69

Mount Holly Springs, Pa., kaolin deposits near___ __ 83-89 

kaolin from, effect of burning on_ 302 

photomicrograph of _____ 300 

Mountain Falls, Va., clay deposits

near_____ __ 117 

Mountain Glen, 111., clay deposits

near _________ 284-289 

Murray, Ky., clay deposits near__ 238,

282-283 

Muscovite, effects of weathering on. 21
312 INDEX.

N. Pae?.

Narvon, Pa., kaolin deposits near_ 89-91 

National Sales Co., clay pit of, near

Hickory Grove, Ky__ 281-282 

Nevada, kaolin deposits in____ 121-126 

New Jersey, clays in, occurrence

of ___________ 202-203 

clays in, utilization of____ 203-204 

North Carolina, kaolins in, by-products from________ 23-25 

kaolins in, composition of____ 25 

distribution of_____ 18-20, 65 

origin of ___ 20-21 

refining of _________ 23-25 

reserves of __ _____ 75-77 

uses of____________ 78-79 

map of western part of_____ 18 

mountain area in, location and

topography of ______ 18-19

nature and occurrence of

kaolins in ______'_ 26-64 

river valleys of, kaolins in___ 19-20 

Nunnelly, A., clay pit of, near Hollow Rock, Tenn___ 225-227

0.

Ohio, glass-pot clays in_______ 133-135 

Okahumpka, Fla., tests of clay from. 291 

Old Hickory Clay & Talc Co., pit of,

near Hickory Grove,

Ky __________ 280-281 

Oligocene clays, occurrences of, in

Florida ________ 289-291 

Oolite of diaspore, photomicrograph

of____________ 297

Oreana, Nev., kaolin deposit near- 121-122

Oriskany group, kaolins from_ 108-120

kaolins from, minerals in____ 293

Orton, Edward, jr., cited______ 105

Overton, N. C., kaolin deposit near- 69-70

Oxford, Miss., clay deposits in__ 253-255

section of city well at_ 241

Owensville.Mo., clay deposits near_ 141-143

PPaducab Clay Co., pit of, near Briensburg, Ky___ ___ 238 

pit of, plate showing section in_ 238 

pits of, near Benton, Ky__ 237 

Paints, use of sedimentary clays

In _________ 11,188-189 

Paper, clay suitable for, production of_______ 6

clay suitable for, properties of 10,

187-188 

Paragon Kaolin Co., properties of,

near Langley, S. C 174-177 

unconformity in pit of, plate

showing 174 

Paris, Tenn., clay pit near_______ 229-230

Parker Kaolin Co., mine of, near

Warrenville, S. C__ 211-213

Parmelee, C. W., acknowledgment to_ 1

cited__ __ 273, 288, 289

tests of clays by________ 208, 210

Patton property, near Warriorsmark,

Pa., description of_ 96-97

Page. 

Payne & Sullivan mine, near Bryson,

N. C., description of 44-46 

pit No. 1 of, plate showing___ 33 

Peck, F. B., acknowledgment to_ 1 

Geology of the Saylorsburg district, Pa______ 109-111

Peerless Clay Co., pit of, plate showing____________ 174 

property of, near Langley,

- S. C_________ 177-181 

Pegmatites, in the North Carolina

mountains, nature of_ 26-27 

in the Piedmont Plateau region 

of North- Carolina, 

kaolins from______ 65-75 

Penland, N. C., analysis of kaolin

from _ __ 25 

kaolin mines near_ _ 39-41, 47-51 

kaolinlzation at ______ 22-23

Pennsylvania, clays of Carboniferous

age from __________ 135

kaolin from Cambrian schists in_ 82-91 

kaolin from the Oriskany group

in____________ 109-116 

kaolin pits in . 18 

central, kaolin from Cambrian

quartzite in_______ 92-99 

Penny winkle Hill, near luka, Miss.,

tests of clay from_ 208-209 

Perry, Ga., clay pit near 224 

Petersburg, Pa., clay deposit at 115 

Philadelphia Clay Co., kaolin deposit of __ _ _ 85 

Photomicrographs of clays_ - 296,

297,300, 301 

Piedmont Plateau, location and

topography of- - 18,19 

Piedmont Plateau region of North

Carolina, kaolins in 65-75 

Pinson, Tenn., clay deposit at__ 263-264 

Pitt-Rowland mine, east of Oreana, 

Nev., kaolin deposit 

in___________ 121-122 

kaolin from, effect of burning

on____________ 302 

photomicrograph of-__ 300 

Porter property, near Franklin,

N. C., description of__ 41-42 

wall of pit of, plate showing 33 

Porters Creek clay, minerals in 295 

Pottery, use of sedimentary clays in_ 189 

Pratt, N. P., analyses by 23 

Product Sales Co., pit of, plate showing________ 102

P/roduction, statistics of 6 

Prospecting for kaolin, suggestions

on _____________ 77-78 

Pryorsburg, Ky., clay deposit at 277-280 

Puryear, Tenn., clay deposits near. 272-275

Q.

Quartz, change in, from firing 300 

effects of weathering on 20-21 

form of, in pegmatite 27 

microscopic identification of 296 

removal of_ 24
INDEX. 313

Page.

R.

Raritan formation, clays of, in

Maryland________ 204 

clays of, in New Jersey____ 202-204 

Rayflin, S. C., Micldendorf arkose

clay near_ _ 213-215 

Refractory bond clay, importation

of____________T 3-4 

qualities of_____ _____ 11-14 

Republic Mining & Manufacturing 

Co.'s mine, near Andersonville, Ga., clay 

in ____________ 234-235 

plate showing_ _ _ 197 

near Little Rock, Ark., clay in_ 120 

Residual clays, minerals in____ 292-294 

summary on _ ___ 126-127 

Residual clays of undetermined deri- &

vation, localities of_ 128-147 

Ries, H., cited ____ ___ 68

The deposit of indianaite near 

Huron, Lawrence County, Ind________ 154-157 

Ripley, Miss., clay deposit near__ 235-230 

Ripley formation, clays of_____ 223-230 

clays of, minerals in_ __ 294-295 

Rock Hill Clay Co.'s pit near Shirleysburg, Pa., description of ________ 115-116 

Roda mine, near Webster, N. C.,

description of 30-31 

Roe, R. B., cited____________ 10 

Rosebud, Mo., clay deposits near_ 144-145 

Ross property, near Beta, N. C., description of_ _ _ 55-57 

Rutile, microscopite identification of 298-299 

S.

St. Clair, Stuart, cited ,. ____ 285 

St. Louis, Mo., clay deposits near_ 131-133 

Sampling kaolin deposits, suggestions for _ 78 

Sandusky Portland Cement Co.,

kaolin mine of-_ 85-86 

Sassman, C. C., clay pit of. near

Owensville. Mo___ 142-143 

clay pit of, plate showing___ 103 

Saylorsbnrg district, Pa., geology

of_____-______ 109-111 

kaolin from, effect of burning on_ 302 

mines in_____________ Ill-rll3 

nature and uses of the clays of_ 111 

Scates-Reynolds Clay Co., sagger clay 

pit of, near Henry, 

Tenn__________ 267-269 

sagger clay pit of, plate showing____________ 263 

Schists, Cambrian, kaolins from__ 65, 

68-75, 82-91

Schroyer, C. R., acknowledgment to_ 1 

Sedimentary clays, geologic relations

of___________ 162-163

methods of mining ___ 163-164

minerals in ____________ 294-295

 white-burning, properties of__ 7 9

Selma chalk, clay in_________ 222-223

Page. 

Slielton, T. L., kaolin deposit of,

near Vesuvius, Va _ 103 

Shepard property, east of Beatty,

Nev., clay deposit on 124 

Shirloysburg, Pa., clay deposit near,

description of ____ 115-116 

Shockley, H. H., clay pit of, near

Bland, Mo _______ 145

lK, A. R., kaolin deposit of, near

Loffon, Va ______ 102-103 

Sillimanite, development of, by

firing ___ 300-301, 304-305 

Slip clay, production of ________ 6 

Smith, J. A., property of, at Bessemer City, N. C__ ___ 65-67 

Smith prospect, near Micaville,

N. C., description of 61 

Society Hill, S. C., Middendorf

arkose clay near __ ___ 222 

Somers, R. E., microscopic study of

clays _________ 292-305 

photographic work by _ _ - _ 1 

Somerville, Dr. T. H., clay bed of,

at Carrollton, Miss 250-252 

Scuth Carolina, clays of the Middendorf arkose member

In ___________ 211-222 

kaolin in___ _________ _ __ 79-82

Lower Cretaceous clays in, geol:

ogy of_ ________ 164-168

overburden on ____ _ _ 192

pits in ___________ 168-186

uses of ___________ 186-190

working of_____ __ _ 190-194

map of _____________ 164

South Carolina Clay Co., property

of, near L a n g 1 e y ,

S. C __________ 171-174 

South Mountain region, Pa., kaolin

deposits In __ _____ 83-89 

Southeastern States, map of 162 

Southern Ball Clay Co., clay beds of,

near Enid and Crevi,

Miss __________ 247-248 

Sparks, C. S., clay pit, near McKenzle, Tenn., description

of _______ __ 266-267 

Sparks mine, near Sprucepine,

N. C., description of 39-41 

Spencer Hollow, Ohio, clay deposit

at __________ __ 133-134 

Spherulite of kaolinite (?), photomicrograph of 297 

Spinks, H. C., Clay Co., pit of, near

Henry, Tenn ____ _ _ 2G9 

Sprucepine, N. C., analysis of kaolin from __________ 25 

kaolin mines near __ __ 36-41 

Statesville, N. C., kaolin deposit

near ______ _ ____ 71-72 

Steele, R. L., property of, near

Bosticks Mills, N. C - 72-75 

Stephenson, L. W., cited __ ___ 223 

Sterrett, D. B., cited.. ____ 26-27 

Stoneware clay, production of .6

77412 22- -23
314 INDEX.

Page. 

Storrnstown, Pa., kaolin deposit

near ____.______ 94-95 

" Stormville " series, kaolin deposits

in, in Pennsylvania. 109-111 

Stout, Wilbur, glass-pot clays in /

Ohio__________ 133-135 

Sylva, N. C., analyses of kaolin

from___________ 25

T.

Tclluride, Nev., clay deposits near_ 124-125 

Tennessee, clay of Selma chalk in_ 222-223 

clays of the Lagrange formation

in ___________ 260-276 

clays of the Ripley formation

in ___________ 225-230

map of western part of_____ 226

Porters Creek clay in______ 236

tests of clays from____ 227, 228-229

Tertiary deposits, clays of, minerals

in _____________ 295 

clays of, nature and distribution

of___________ 230-291

Tests of clays from Alabama. 130-131, 205

from Arkansas________ 257-258

from Florida__________ 290-291

from Georgia____ 199, 225, 234, 235

from Illinois__________ 286-289

from Kentucky______ 277-278, 281

from Mississippi________ 207, 208,

210, 241-242, 244, 245,

246, 248, 249-250, 251-

252, 252-253, 254-255

from Missouri 106, 107, 132, 133, 146

 from Nevada_____ 122,123,125,126

from Ohio____________ 134-135

from Pennsylvania 112,113,114,115

from South Carolina_____ 169-171,

173, 175-177, 178-181,

183-184, 212, 214-215,

217-218, 219-220, 232

from Tennessee_______ 265-266,

267, 268, 271, 273-275 

from Virginia ____________ 100,

102, 103, 104, 118, 119 

Texture of clays_____________ 300 

Thomas prospect, near Micaville,

N. C., description of__ 60 

Tile, glazed, use of sedimentary

clays in _________ 189

Tlshomingo, Miss., Tuscaloosa clay

near ___________ 206 

Titanite, microscopic determination

of_____________ 299 

Tocowa, Miss., clay deposit near_ 249-250 

Toecane, N. C., kaolin pits near__ 36 

Toelke & Heidel flint-clay pit, near 

Rosebud, Mo., plate 

showing______ 144

Tourmaline, microscopic determination of__________ 299 

photomicrograph of grain of __ 296 

products of weathering of 21, 27 

Trenton, S. C., clay deposit near 185-186 

Troy,. N. C., kaolin deposit near 68-69

Page. 

Tuscaloosa formation, clays of, in

Alabama________ 204-205 

clays of, in Mississippi____ 205-211

U.

United States Tin Co.'s mine, near 

Lincolnton, N . C., 

kaolin in________ 67-68

Upper Cretaceous clays, occurrence

and utilization of_ 202-230

Upper Mill, Pa..kaolin deposits near_ 85-86

United States Clay Co., pits of, north

of Murray, Ky _____ 238

Uses of kaolins of North Carolina_ 78-79 

of sedimentary clays ____ 186-190, 200

V.

Valentine property, near Etowah,

N. C., description of__ 57-58 

Veatch, Otto, acknowledgment to___ 194 

Vesuvius, Va., kaolin deposit near 103 

Virginia, kaolin from Cambrian

shale in________ 99-104 

kaolin from pegmatite in____ 18

W.

Warrenville, S. C., Middendorf

arkose clay near__ 211-213 

Warriorsmark, Pa., kaolin deposit

near ___________ 96-97 

Washing of kaolin, methods of___ 128 

process used by the Holly Clay

Corporation_______ 86-88 

Watts, A. S., cited___________ 30, 63 

Weathering, of pegmatite, results of- 20-21 

Webster, N. C., analyses of kaolins

from____________ 24,25 

West Cornwall, Conn., kaolin deposit near_ ____ 99 

West Virginia, kaolin deposit in___ 117 

Wheeler, H. A., cited ________ 104

White-ware clays, kinds included in__ 6 

Whitlock, Tenn., clay pits near__ 269-271 

Whittaker Clay Co.'s pit, Narvon,

Pa., description of 90

plate showing-- 87

Wickliffe, Ky., clay deposits near- 282, 283

Wilcox group, clays of ______ 238-259

clays of, minerals in_ __ 295 

Wilson, M. E., acknowledgment to 1 

Wilson mine, near Micaville, N. C.,

description of 35 

Wing, N. C., kaolin deposit near. 62-63 

Woodbury Clay Co., kaolin deposit

of___________ 98 

Woodrow, N. C., analysis of kaolin

from_________ 25 

kaolin mine near _ . __ 3.1 34 

Wyatt mine, near Micaville, description of _________ 35-36

Zircon,-microscopic determination of_ 299

o