DEPOSITS OF CLAIBORNE AND JACKSON AGE IN GEORGIA. 

By CHARLES WYTHE CooKE and l-IAROLD KuRTZ SHEARER. 

INTRODUCTION. 

In 19 11 the Goo logical Survey of Georgia 

published as Bulletin 26 a "Preliminary 

report on the geology of the Coastal Plain of 

Georgia," by Otto Veatch and Lloyd William 

Stephenson, prepared in cooperation with the 

United State;;; Geological Survey under the 

9Upervision ofT. Wayland Vaughan, geologist 

in charge of Coastal Plain investigations, who 

contributed the determinations of the invertebrate fossils of the Tertiary and Quaternary 

formations. Although this report constituted 

a decided advance in our knowledge of the 

geology of the Coastal Plain of Georgia, it 

was admittedly of reconnaissance character, 

and corrections and additions to it were to be 

&Xpected. During the last few years field work 

has been prosecuted vigorously in the Coastal 

Plain of Georgia, and the additional information thus accumulated throws light upon 

certain problems of stratigraphy left unsolved 

by Veatch and Stephenson and alters considerably some of their correlations. The 

object of the present paper is to present the 

new evidence regarding the age and correlation 

of the Eocene formations of Georgia and to 

revise in accordance with present knowledge 

the descriptions of the deposits of Claiborne 

and Jackson age. 

SUMMARY OF EOCENE AND LOWER OLIGOCENE 

FORMATIONS AS KNOWN TO 1911. 

The chapters on the Eocene and lower Oligocene formations in the Coastal Plain report 

will be briefly summarized. Veatch and Stephenson recognized the following formations: 

:tower Oligocene: 

Vicksburg formation. 

Eocene: 

Jackson formation. 

Claiborne group. 

Barnwell sand. 

McBean formation. 

Congaree clay member (at base). 

· Wilcox formation. 

Midway formation. 

The Midway and Wilcox formations are 

confined to the region west of Perry, Houston 

County. East of Perry both formations are 

overlapped by younger strata. 

The McBean formation of Veatch and 

Stephenson consists mainly of clays in the 

nature of fuller's earth, of marls, sandy limestones, and calcareous glauconitic sands. An 

extensive marine fauna containing many 

characteristic lower Claiborne mollusks occurs 

in the marls on McBean Creek, Burke County, 

and also in the lower part of Shell Bluff on 

Savannah River. A aeries of fuller's earth 

grading into calcareous clay whi~h is exposed 

at short intervals from Grovetown, Columbia 

County, southwestward along the Fall Line 

to Bibb and Twiggs counties, was correlated 

on lithologic grounds with Sloan's Congaree 

"phase" of the South Carolina Eocene and 

designated the "Congaree clay member of the 

McBean formation." 

The Barnwell sand, correlated with Sloan's . 

Barnwell "phase" in South Carolina, consists 

largely pf unconsolidated red and varicolored 

sands, with some indurated beds of gray sandstone and lumps of silicified limestone or flint. 

They stated that it overlies directly the McBean 

formation and is in contact with both the 

marls and the "Congaree" clay member of 

that formation, but the nature of the contact 

had not been satisfactorily determined. In 

places the Barnwell overlaps the McBean 

formation and rests directly upon the Lower 

Cretaceous. It carries a marine fauna which 

contains a number of species in common with 

the Gosport sand of Alabama (upper Claiborne) and was correlated with that formation. 

The Jackson formation as originally mapped 

by Veatch and Stephenson included a smaU 

patch on Chattahoochee River, a small outlier on the Cretaceous at Rich Hill, Crawford 

County, and a long, narrow area running from 

a point about 8 miles southwest of Sandersville to a point 6 miles east of Montezuma. _ On 

41 
42 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

the map accompanying the report on the 

ground waters of tne Coastal Plain of Georgia 

by the same authors 1 this area was extended 

into southwestern Sumter County. 

The Vicksburg formation of Veatch and 

Stephenson included besides strata of true 

Vicksburg age the great mass of limestone 

underlying the lower drainage basin of Flint 

and Chattahoochee rivers and forming the 

northern extension of the Ocala limestone of 

Florida. 

RECENT INVESTIGATIONS AND THE INCEPTION 

OF THE PRESENT WORK. 

The recent discovery that the Ocala limestone is of Jackson age 2 has largely increased 

the known areal extent of the deposits of that 

aga, at the expense of the Vicksburg formation. 

The area of deposits of Jackson age has been 

further extended by Brantly/ to include most 

of those parts of Wilkinson and Twiggs counties formerly mapped as Claiborne. Brantly 

also expressed the opinion that th6 "Congaree" 

clay of previous reports seems to be the continuation of the Jackson limestone and fuller's 

earth of Houston County.4 The same opinion 

concerning the stratigraphic relations of the 

"Congaree" clay was reached by H. K. Shearer, 

assistant State geologist, in the course of field 

. investigations of the fuller's earth deposits of 

Georgia,5 but as the published .correlation of 

the "Congaree" clay with the Claiborne group 

seemed to be supported by as good paleontologic evidence as the correlation of the limestone with the Jackson, he was uncertain to 

which epoch the fuller's earth deposits properly belong. 

At the request of Prof. S. W. McCallie, State 

geologist of Georgia, C. Wythe Cooke was assigned by the United States Geological Survey 

to accompany~· Shearer over the field, with 

the object of reconciling the discrepancies between the apparent stratigraphic relations of 

the deposits in eastern and central Georgia as 

determined by Messrs. Brantly and Shearer and 

1 U.S. Geol. Survey Water-Supply Paper 341, pl. 3, 1915. 

2 Cooke, C. W., The age of the Ocala limestone: U. S . . Geol. Survey 

Prof. Paper 95, pp. 107-117, 1915. 

3 Brantly, J. E., Report on the limestones and marls of.the Coastal 

Plain of Georgia: Georgia Geol. Survey Bull. 21, 1916. 

4 Idem, p. 8. 

n Since · the completion of this manuscript Shearer's report on the 

bauxite and fuller's earth of the Coastal Plain of Georgia has been published as Bulletin 31 of the Georgia Geological Survey. He has adopted 

the correlations proposed here. · 

the ages indicated by previously published lists. 

of fossils. 

Field work was done by the writers jointly 

from March 20 to April 19, 1916, and during 

that time all the most significant known exposures of Eocene strata in the region between. 

Flint and Savannah rivers were visited and 

collections of fossils were made wherever· 

possible. 

The succeeding fortnight was spent by Mr. 

Cooke in visiting the type localities of the South 

Carolinian Eocene for the purpose of determin-· 

ing the propriety of applying the names· Congaree and Barnwell to geologic formations in. 

Georgia. Mr. Shearer subsequently examined. 

the Claiborne deposits in Georgia west of Flint. 

River. The results of Mr. Cooke's previous. 

(1914) studies of the Ocala limestone are also· 

incorporated in this paper. 

The writers are indebted to Prof. E. W .. 

Berry, of Johns Hopkins University, and to· 

Dr. R. S. Bassler, of the National Museum, for 

reports on the plant remains and Bryozoa, 

respectively, and to Dr. Joseph A. Cushman 

for identifications of the Foraminifera. The 

other fossils collected in the course of thisinvestigation have been identified by Mr. 

Cooke, who has also had the privilege of ex--

amining the collections in the National Museum 

upon which were based the correlations pub--

lished in the preliminary report on the geology· 

of the Coastal Plain of Georgia. The present .. 

paper was prepared under the direction of T. 

Wayland Vaughan, geologist in charge of 

Coastal Plain investigations of the United 

States Geological Survey, who has given it. 

continuous peraonal attention and has madea number of suggestions that have been adopted_ 

by the writers. 

CRITICAL SECTIONS AND EOCENE FAUNAS OF· 

EASTERN GEORGIA. 

DRY BRANCH. 

In the vicinity of Dry Branch, Twiggs. 

County, are good exposures of Eocene beds.. 

which were referred to the Claiborne group by 

Veatch and Stephenson, on the basis of 

Vaughan's identifications of the fossils, but. 

which later discoveries have shown to be of 

Jackson age. The following section is typical. 

The formation names used are those adopted in_ 

this report. 
DEPOSIT'S OF CLAIBOR.NE AND JACKSON AGE . IN GEORGIA. 43 

Section at the mines of the Georgia Kaolin Co., 2 miles east 

of Dry Branch. 

Vicksburg or Barnwell formation: Feet. 

7. Red sand, capping hill, about. . . . . . . . . . . 80 

Barnwell formation (Twiggs clay member): 

6. Greenish-gray fuller's earth (buff when 

dry)- -.• -. ---. - ----. - " ---- _. " -- ----- --- 3o-40 ± 

Ocala limestone (Tivola tongue): 

5. Impure white argillaceous limestone, 

grading into fuller's earth. Pinches 

out toward the north and northwest and 

is absent in the northwestern part of the 

quarry. Contains many Bryozoa. Separated from the underlying bed by a 

somewhat irregular contact............ 0- 5 

Barnwell formation (lower part): 

4. Yellow sand with black carbonaceous 

stains. Contains a few large bones of 

Basilosaurus cetoides (Owen)1 ••••••••••• 1- 2! 

3. Yellow to red sand, medium coarse, irregularly bedded........................ 12 

2. Gray sandstone with calcareous cement, 

loaded with casts of mollusks. Pinches 

out at north end of quarry, where the 

kaolin is overlain by glauconitic sand.. 0- ~ 

Unconformity. 

Lower Cretaceous: 

1. White kaolin. . . . . . . . . . . . . . . . . . . . . . . . . . . 15-20 

The fossils collected from the basal Eocene 

at this locality are listed below. 

Station 7691. Pit of Georgia Kaolin Co., 2 miles east of 

Dry Branch, Ga. Bed 2 of section. Basal sandstone 

immediately overlying the Lower Cretaceous. Cooke 

and Shearer, collectors, 1916. 

Levifusus trabeatus (Conrad)? 

Levifusus sp. 

Ficus filius (Meyer). 

Turritella sp. 

Mesalia vetusta (Conrad). 

Calyptraea sp. 

N ucula magnifica Conrad. 

Leda cf. L. mater Meyer. 

Leda cf. L. plicata (Lea). 

Leda regina-jacksonis Harris? 

Glycymeris staminea (Conrad)? 

Glycymeris sp. 

· Barbatia cuculloides (Conrad). 

Ostrea trigonalis Conrad. 

Ostrea sp. 

Pteria limula (Conrad)? 

Panope porrectoides (Aldrich). 

Corbula oniscus Conrad var. 

Corbula densata Conrad. 

Phacoides (Miltha) pandatus (Conrad). 

Phacoides alveatus (Conrad) var. 

Phacoides (Here) sp. 

Tellina, 2 sp. 

Macoma sp. 

Metis sp. 

Tagelus sp. 

Meretrix securiformis (Conrad)? 

Protocardia nicolleti (Conrad). 

1 Identified by C. W. Gilmore. 

Many of the mollusks in this list occur in 

both Claiborne and Jackson deposits, but 

Ficus filius, Leda mater, Leda regina-jacksonis, 

·ostrea trigonalis, Meretrix securiformis, and 

Protocardia nicolleti are particularly characteristic of the Jackson and are rare or unknown 

in older beds. M esalia vetusta, which had been 

previously thought to be confined to the upper 

Claiborne (Gosport greensand horizon), has 

recently been found at the base of the Jackson 

formation at Sims, Yazoo County, Miss. 

Basilosaurus cetoides, the zeuglodon, which 

occurs .in bed 4, is so far as known confined to 

the Jackson, and in most places is most abundant near the top. 

According to R. S. Bassler, the Bryozoa in 

bed 5 constitute a fauna peculiar to the middle 

Jackson. The same fauna occurs at Rich Hill, 

Crawford County, and numerous other localities in central Georgia and will be referred to 

for convenience as the Rich Hill faci'es of the 

Jackson fauna. 

The fuller's earth of bed 6, a greenish hackly 

clay of low specific gravity, resembles the beds 

exposed at numerous localities in central and 

eastern Georgia and referred by Veatch and 

Stephe son to the "Congaree" clay member 

of the cBean formation. 

The ed sand at the top of the section was 

correlat d by Veatch and Stephenson with 

the Ba nwell sand, and the underlying beds 

were pi ced doubtfully with the McBean formation. 

Certa"n problems in stratigraphy, which the 

·authors cited were unable to explain under 

the su position that the strata near Dry 

Branch are of Claiborne age, vanish immediately w en it is discovered that the deposits 

are of ackson age. For instance, they say: 3 

Accord ng to Dr. Vaughan the evidence of the fossils 

shows th t Jackson strata occur near the mines of the 

Georgia aolin Co., 2 miles southeast of Dry Branch. 

There is n ~xposure of 15 feet of soft white argillaceous 

marl in a small ravine one-half mile southeast of the clayworking lant, which contains Bryozoa and other fossils 

and is si ilar lithologically to the marl at Rich Hill. It 

lies 10 t 15 feet above the white clay beds of the Cretaceous a d is overlain by 125 feet of bluish or drab laminated sa dy clay and red sand, the clay containing thin 

slabs of q artzite or sandstone. In this vicinity Claiborne 

fossilifer us strata occur at both higher and lower levels 

than thi marl, and the presence of Jackson beds in this 

2 Veatch, Otto, and Stephenson, L. W., Geology of the Coastal Plain 

of Georgia: Georgia Geol. Survey Bull. 26, p. 256, 1911. 

a Idem, . S04. · 
44 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

position implies either a deep erosion unconformity between the two formations or a flexure. Exposures in this 

vicinity, so far as they have been examined, afforded no 

evidence of an unconformity or of any faulting or folding 

of the beds. Further detailed field work is necessary to 

solve this problem of stratigraphy. 

The problem has been solved by the discovery that• the beds higher and lower than 

the marl are Jackson and not Claiborne. 

SOUTH OF PERRY. 

Other localities which presented difficulties 

to Veatch and Stephenson are Mossy Hill and 

Ross Hill, in Houston County. These hills 

are a few miles apart on the escarpment south 

of Mill and Flat creeks, which extends northeastward, approximately parallel to the general strike of the formations of the Coastal 

Plain in this part of the State. Ross Hill is 

crossed on the road from Perry to Elko, 3 

miles south of Perry, and Mossy Hill lies on the 

National Highway (the road from Perry to 

Henderson) about 5.7 miles southwest of Perry. 

The entire section at Ross Hill, with the 

exception of 10 feet at the top, was referred by 

Veatch and Stephenson to the Jackson formation,. and this correlation was supported by 

lists of fossils identified by Vaughan. The 

following section measured by the writers is 

in essen tip] agreement with that of Veatch and 

Stephenson.1 The base of the section is 25 

feet above Mill Creek. 

Section on Perry-Elko road at Ross Hill. 

Oligocene(?): Feet. 

Vicksburg formation(?): 

7. Concealed to edge of plowed field on top 

of hill, which rises a few feet higher. 

The surface is st.rewn with lumps of 

sparingly fossiliferous chert.......... 15 

Eocene (all of Jackson age) : 

Barnwell formation: 

6. Soft cream-colored to yellow sandy limestone with casts of fossils. Lunularia 

distans, Endopachys, Calyptraea, Leda, 

andPecten ................... ~ ...... 4± 

5. Light-colored limestone at base; upper 

part concealed but with debris of soft 

limestone with Periarchus pileus-sinensis and Bryozoa .. _ ... _ . ____ . ___ . _ . . . 15 

4. Hackly cream-colored calcareous clay 

(fuller's earth) with lime concretions. 24 

Ocala limestone (Tivola tongue): 

3. Cream-colored limestone, soft when 

fresh, with a hard ledge at bottom. 

Has been quarried in part. Contains 

Pecten perplanus and many Bryozoa.. 7i 

1 Op. cit., p. 301. 

Section on Perry-Elko road at Ross Hill-Continued. 

Eocene (all of Jackson age)-Continued. :Feet. 

Ocala limestone (Tivola tongue)-Continued. 

2. Soft greenish-yellow limestone, speckled 

with glauconite and with locally indurated nodules or ledges. Very argillaceous toward the top and contains numerous soft, irregular lime 

concretions. Bryozoa .. _ .. _ . _ . _ .. _ . . . 71 

1. Pale cream-colored soft limestone, replete with Bryozoa (Rich Hill fac.:.es 

of Jackson fauna). Hard ledges near 

the top. Contains also Periarchus 

pileus-sinensis. Exposed east of the 

road .. _ . _ . _ ... . _ ...... _ ...... _ . . . . . . 38 

The following section was measured in a 

gully on Ross Hill about 300 yards west of the 

Perry-Elko road. The top of the hill here is 

probably 40 feet or more higher than at the 

road. The base of the section is by barometer 

40 feet above the bridge over Mill Creek. 

Section on Ross Hill 300 yards west of Perry-Elko road. 

Oligocene(?): 

Vicksburg formation (?): Feet. 

14. Red sand with "buckshot" ferruginous lumps. Fragments of fossiliferous chert on top ...... _ . . . . . . . . . . . . . 30 

Eocene: 

Barnwell formation (Twiggs clay member): 

13. Glauconitic clay and f~ller's earth, 

poorly exposed..................... 15± 

12. Glauconitic grains in a matrix of yellowish, calcareous clay. Pecten sp., 

etc ................................ 2!± 

11. Gray hackly clay (fuller's earth); upper 

2 feet containing lenses or nodules of 

glauconitic material resembling bed 

12-... --.. - . -.. - - -.... - . - -... - - - . . . 7! ± 

10. Lens or nodule of greenish-gray limestone with casts of Corbula, probably 

C. wailesiana ......................... 1 

9. Fuller's earth........................ 4 

8. Limestone ..... _._._ ..... _ .... __ .. __ 1 

7. Calcareous fuller's earth. . . . . . . . . . . . . • 15 

6. Continuous ledge of gray limestone 

with poorly preserved mollusks..... ! 

5. Calcareous fuller's earth containing 

soft, white chalk nodules........... 3! 

4. Hard light-gray limestone, softer at 

bottom. Contains some Bryozoa, 

Flabellum, Turritella carinata, Mesalia vetusta, Pecten, Meretrix, and 

Periarchus pileus-sinensis ............ - 3 

3. Hacldy cream-colored calcareous clay 

(fuller's earth). The base of this bed 

·is the same as the base of bed 4 of 

preceding section ............. - - . . . . 35 

Ocala limestone (Tivola tongue): 

2. Soft argillaceous limestone loaded with 

Bryozoa (Rich Hill facies of Jackson 

fauna). Contains also Ostrea trigonalis and Pecten perplanus. . . . . . . . . 7 

1. Hard and soft ledges of limestone with 

..Bryozoa, Pecten perplanus, and Periarchus pileus-sinensis very abundant. 17 
DEPOSITS OF CLAIBORNE AND .JACKSON ·AGE IN GEORGIA • . 45 

Bed 4 is particularly significant in that it 

shows the presence of Turritella carinata and 

Mesalia vetusta, which were considered by 

Vaughan to be diagnostic upper Claiborne 

fossils, well above the base of the deposits of 

Jackson age. 

The geologic conditions at Mossy Hill appear 

to be similar to those at Ross Hill, but the exposures are less complete. The following section, exposed in and near an old quarry about 

100 yards east of the National Highway, extends from a gully below the quarry to a level 

bench on the road. 

Section at Mossy Hill. 

Oligocene, Vicksburg formation: 

13. Red argillaceous sand with chert fragments, 

commencing at a level bench on the 

National Highway and capping the upland area to the south . . . . . . • • . . . . . . . . . . . . 30 

Eocene: Barnwell formation (Twiggs clay member): 

12. Mostly concealed, but interbedded fuller's 

earth and bryozoan limestone are exposed in 

a gully east of the road a few feet below the 

bench . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 

11. Yellow to green, partly indurated glauconitic 

marl..................................... 5 

10. Calcareous clay resembling fuller's earth, with 

a locally indurated stratum at top......... 5! 

9. Impure yellowish limestone with casts of 

fossils. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2! 

8. Concealed. . . . .. . .. .. .. .. .. .. . .. .. .. .. .. .. 6 

7. Clay or fuller's earth with chalk concretions.. 2 

6. Concealed ................................ 14 

5. Calcareous · fuller's earth, exposed on roadside. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

4. Hard limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . . ! 

3. Calcareous fuller's earth.................... 2! 

2 Argillaceous fossiliferous limestone with hard 

ledges; quarried .......................... 11 

1. Gray calcareous clay with lime nodules below, 

grading upward into fuller's earth with lime 

nodules; exposed in gully below quarry ... 21 

From bed 2 the following species were 

obtained: 

Station 7682. Quarry on Mossy Hill. Cooke and Shearer, 

ollectors, 1916: 

Endopachys sp. 

Lunularia distans (Lonsdale). 

Turritellacarinata Lea. 

Mesalia vetusta (Conrad). 

Leda cf. L. plicata (Lea). 

Glycymeris sp. 

Pecten perplanus Morton. 

Phacoides alveatus (Conrad). 

Miltha claibornensis (Conrad). 

Dentalium sp. 

28288°-19--4 

The st atmn immediately below the bed 

from, whi h these species were oollected contains Bry zoa which R. S. Bassler refers to 

the horizo of the deposits of Jackson age at 

Baldock, . C. The stratum in the quarry 

from whi h the fossils were collected seems 

to be ide tical with bed 4 of the section on 

Ross Hill west of the Perry-Elko road. Not 

only are he species, so far as they oan be 

identified, the same, but the rooks in which 

they are mbedded look alike, and the sections bot above and below the fossiliferous 

zone are imilar. Moreover, the topographic 

relations f the two localities are such as to 

indicate t at the beds at both are at the same 

horizon, rovided, of course, that there are 

no struct ral disturbances, of which there is 

no eviden e. 

In the oastal Plain report1 the lower part 

of the sec ion at Mossy Hill was referred to the 

Claiborne group on the basis of collections of 

fossils m de by T. W. Vaughan and S. W. 

McCallie. The species collected by Vaughan 

at Mossy Hill are listed as follows: 

Flabe lum cuneiforme' Lonsdale. 

Turbi olia pharetra Lea. 

Endo achys maclurii (Lea). 

*Turri lla carinata Lea. 

*Mesal a vetusta (Conrad). 

Calyp raea aperta (Solander). 

Dent lium thalloides Conrad. 

Nucu a ovula Lea. 

Leda p. 

Leda p. 

Glyc eris idoneus (Conrad)? 

*Phac ides alveatus (Conrad). 

Vene icardia, 2 or 3 sp. 

Cyth rea sp. 

Crass tellites sp. 

Corb la on:iscus Conrad or wailesiana Harris. 

Corb la densata Conrad? 

Geologic orizon, Claiborne. Species marked * are 

not known f om the Jackson. 

It will e noted that the only species ohe<~ked 

as not kn wn from the Jackson are Turritella 

carinata, l.esalia vetusta, and Phacoides alveatus. The first and second have since been 

found in he beds of Jackson age at Ross Hill, 

and the s ond and third at the mine of the 

Georgia One of the undetermined sp ies of Leda listed occurs also at the 

latter pla e. 

1 Veatch, tto, and Stephenson, L. W., op. cit., pp. 258-260. 
46 SHORTER CONTlUBUTIONS TO GENERAL GEOLOGY, 1918. 

The fossils collected by McCallie are listed 

as follows: 

Turbinolia pharetra Lea. 

Flabellum cuneiforme Lonsdale. 

Plejona petrosa (Conrad). 

*Turritella carinata Lea. 

Mesalia vetusta (Conrad). 

Dent'alium thalloides Conrad. 

Nucula ovula Lea. 

Leda. 

*Glycymeris trigonella (Conrad). 

Pteria sp . 

*Phacoides alveatus (Conrad). 

*Phacoides aff. P. claibornensis (Conrad). 

Venericardia pl~nicosta Lamarck. 

*Venericardia alticostata (Conrad). 

Cytherea sp. 

*Crassatellites protextus (Conrad). 

*Corbula oniscus Conrad. · 

*Pteropsis lapidosa (Conrad). 

Species marked * are not known from beds above 

the Claiborne. Pteropsis lapidosa is characteristic of the 

lower Claiborne. 

This does indeed look like a Claiborne fauna, 

and with the data then available Vaughan was 

perfectly justified in referring these fossils to 

the Claiborne group; but, as we shall see later, 

nearly all the species checked have since been 

found associated with Jackson fossils. The 

exception to these is P~eropsis Zapidosa, which 

elsewhere seems to be confined to the lower 

Claiborne. As this collection of fossils apparently is not now in the National Museum, the 

identifications of the species could not be 

checked nor could the matrix be examined to 

ascertain whether there had been accidental 

mixture of specimens from different localities. 

There is some uncertainty as to the locality 

at which the fossils ascribed to Mossy Hill were 

obtained. According to Veatch and Stephenson/ Mossy Hill is on the Perry-Elko road 4! 

miles south of Perry, a location corresponding 

nearly wi~h that of Ross Hill. However, as 

there seems to be little doubt that the horizon 

is the same as that from which the writers obtained Turritella carinata and Mesalia vetusta, 

the exact locality is of no particular importance. 

VICINITY OF GIBSON. 

A collection made by the writers from sandstone ledges exposed on the hillside east of 

Rocky Comfort Creek, on the Brassell property, 2 miles northeast of Gibson, Glascock 

1 Op. cit., p. 258. 

County, shows the presence in Georgia of a 

fauna not previously recognized east of Arkansas. The fossils are preserved in the form of 

hollow molds or siliceous pseudomorphs, some 

of which have weathered out of the sandy 

matrix. The rock, which is an indurated 

facies of the basal sand bed of the Eocene that 

is of widespread distribution in this part of the 

State, is exposed to a thickness of 3 or 4 feet 

but probably extends somewhat deeper. It 

lies not far above the Cretaceous, but the contact is not exposed here. The fossils collected 

are enumerated in the accompanying list, in 

which the initials C and J signify that the 

species so marked occur elsewhere in Claiborne 

and Jackso.n deposits, ~espectively. 

Station 7710. Brassell property, 2 miles northeast of 

Gibson, Glascock County. Cooke and Shearer collectors, 1916. 

CJ Flabellum cuneiforme Lonsdale. 

J Astrhelia burnsi Vaughan? 

CJ Cancellaria gemmata Conrad. 

Olivella sp. 

CJ Margin ella semen Lea? 

Psilocochlis mccalliei (Dall). 

CJ Lapparia pactilis (Conrad). 

CJ Plejona petrosa (Con~ad). 

J Levifusm; branneri Harris. 

CJ Levifusus trabeatus (Conrad). 

CJ Mazzalina inaurata (Conrad) var. 

Fusinus aff. F. bellus (Conrad). 

J Murex marksi Harris. 

CJ Pseudoliva vetusta (Conrad). 

CJ Calyptraphorus velatus (Conrad). 

Cerithium sp. 

J Ficus filius (Meyer). 

CJ Turritella carinata Lea. 

CJ Mesalia vetusta (Conrad). 

CJ Natica minima Lea. 

J Natica permunda Conrad? 

Dentalium sp. 

J Leda regina-jacksonis Harris. 

OJ Leda multilineata Conrad? 

OJ Glycymeris staminea (Conrad) 

OJ Pteria limula (Conrad). 

Orenella sp. 

Pecten n. sp. 

OJ Corbula densata Conrad. 

CJ Phacoides (Miltha) claibornensis (Conrad). 

Phacoides sp. 

OJ Crassatellites protextuo (Conrad) var. 

Crassatellites n. sp? 

OJ Macrocallista perovata (Conrad)? 

CJ V enericardia planicosta (Lamarck). 

C Venericardia alticostata Conrad var. 

To this list should be added the following, 

which were obtained with other fossils from 

the same horizon at station 7711, on the east 
DEPOSITS OF CLAIBORNE AND J" ACKSON AGE IN GEORGIA. 4.7 

side of Deep Creek, 3! miles northeast of Gibson 

and about 1! miles from the Brassell locality: 

J Turritella clevelandia Harris. 

Leda plicata (Lea) var. 

Trinacria? sp. 

J Corbula wailesiana Dall. 

The section there is as follows: 

Section on roadside east of Deep Creek, 3! miles northeast of 

Gibson. 

Eocene (Barnwell formation): Feet. 

7. Mottled red or orange-colored sand. . . . . . . . . . . 50± 

6. Fuller's earth with sand laminae ........... 11 

5. Unconsolidated sand similar to No. 4. . . . . . . 5 

4. White or gray fossiliferous-sandstone like that 

on Brassell property. . . . . . . . . . . . . . . . . . . . . . 6 

3. Gray clayey sand........................... 4 

2. Concealed ............. ~ ............ , ..... 10 

Cretaceous: 

1. Kaolin and white sand ...................... 15 

This fauna, which occurs within 15 Jeet of 

the Eocene-Cretaceous unconformity, bears a 

remarkably close resemblance to that occurring 

at White Bluff and Crowleys Ridge, Ark., 

which was formerly referred to the Claiborne 

group but is now correlated with the lower 

Jackson. 1 It is rather surprising to encounter 

such species as Levjfusus branneri, Murex · 

rnarksi, and Turritella clevelandia, which are 

typical of the Jackson deposits in Arkansas, 

so far east of their previously known range; 

but their presence, as well as the general aspect 

of the fauna, is good evidence that the beds 

containing them occupy approximately the 

same stratigraphic position. The presence of 

Astrhelia burnsi, Ficus filius, Natica perm1,knda, 

Leda regina-jacksonis, and Corbula wailesiana 

affords strong additional evidence that the 

deposits are of Jackson age. 

It will be noted that this list, which is much 

more comprehensive · than any previously compiled from this region, contains nearly all the 

species that were considered by Vaughan to be 

diagnostic of the upper Claiborne. There are, 

in addition, a few species that are abundant 

at this horizon in Georgia but have not yet 

been found elsewhere. Among these may be 

mentioned Psilocochlis mccalliei and an undescribed species of Pecten which has hitherto 

been confused with Pecten wilcoxii and P. 

wahtubbeanus. 

which were collected by McCallie on the EngUsh plantation, 1-! miles north of Gibson,' were 

referred by Veatch and Stephenson 2 to the 

McBean formation. The revised list follows: 

Station 3943. English plantation, 1! miles north of 

Gibson. S. W. McCallie, collector, 1904. 

Flabellum cuneiforme Lonsdale. 

Endopachys maclurii (Lea). 

Mazzalina inaurata (Conrad). 

Plejona petrosa (Conrad). 

Turritella clevelandia Harris. 

Turri tella sp. 

Pecten n. sp. 

Pteria limula (Conrad)? 

Panope sp. 

Phacoides (Miltha) claibornensis (Conrad). 

Venericardia alticostata Conrad va'r _. 

The same fauna has. been , recognized at 

several localities between GlasoQck and Bibb 

counties and is usually found in more or less 

indurated gray sandl?tone resembling that near 

Gibson. All these exposures were referred 

by Veatch and Stephenson to the Claiborne 

group-some to the McBean formation, others 

to the Barnwell sand. 

BROWNS MOUNTAIN AND VICINITY. 

At Browns Mountain, Bibb County, 9 miles 

southeast of Macon, the strata were referred to 

the Barnwell sand.3 

At this locality the main exposures consist of 

about 20 feet of hard gray sandstone, part of 

which appears to grade into sandy limestone. 

It contains fossils that are locally abundant 

but are not very well preserved. Above the 

sandstone are poor exposures of bryozoan 

limestone with Pecten perplanus ?. Beneath 

the s~ndstone are incomplete exposures of 

fuller's earth and sand. 

The relations are more evident on a hill 

on the Marion road, four-tenths of a mile 

southwest of Bond's store, where the following 

section was observed: 

Section on Marion road 9 miles southeast of Macon. 

Eocene: Feet. 

6. Hard sandstone and quartzite, to top of hill. . . 7 

5. Mottled piastic clay... . . . . . . . . . . . . . . . . . . . . . . 3 

4. Red sand ................ : .................. 4 

3. Soft fossiliferous sandstone .................... 0-4 

2. Basal conglomerate;· white kaolin pebbles in 

cross-bedded sand. Contact with Cretaceous 

Fossils representing this same horizon and not precisely located because of lithologic 

embedded in a similar matrix of gray sandstone similarity---------------------------------- 55 

Cretaceous: 

I Stephenson, L. W., and Crider, A. F., Geology and ground waters 

of northeastern Arkansas: U.S. Geol. Survey Water-Supply Paper 399, 

pp. 73-84, 1916. 

1. Coarse white kaolinic sand to stream leveL . . . 65 

2 Op. cit., p. 273. a Idem, pp. 25S-260. 
48 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Stratum 3 of the section consists of a discontinuous ledge of sandstone which in places is 

reduced to lumps embedded in incoherent 

sand. It contains casts of mollusks, including 

Pecten n. sp. Bed 6 is also unequally indurated but is more persistent than bed 3. It 

carries P eriarchus pileus-sinensis and other fossils. Beds 3 to 6 are equivalent to the hard 

rock on Browns Mountain, half a mile away. 

The following lists enumerate the species 

collected in this vicinity: 

Station 7695. Hilltop on Macon-Marion road four-tenths 

of a mile southwest of Bond's store, Bibb County. 

C. Wythe Cooke, collector, 1916. 

Nucula ovula Lea? 

Leda regina-jacksonis Harris? 

Glycymeris sp. 

Pecten n. sp. 

Cytherea sp. 

Periarchus pileus-sinensis (Ravenel)? 

Station 7696. Browns Mountain, near Bond's stor.e, 9 

miles southeast of Macon. C. Wythe Cooke, collector, 

1916. 

Flabellum cuneiforme Lonsdale. 

Lunularia sp. 

Turri tella sp. 

Mesalia vetusta (Conrad). 

Calyptraea sp. 

N ucula spheniopsis Conrad. 

Leda mater Meyer. 

Pecten n. sp. 

Pecten perplanus Morton? (cast of interior). 

Diplodonta sp. 

Phacoides (Miltha) claibornensis (Conrad). 

Protocardia sp. 

Crassatelli tes sp. 

Station 3993. Browns Mountain. S. W. McCallie, collector, 1909.1 

Flabellum cuneiforme Lonsdale. 

Endopachys maclurii (Lea). 

Periarchus pileus-sinensis (Ravenel). 

Calyptraphorus velatus Conrad. 

Turritella carinata Lea. 

Mesalia vetusta (Conrad). 

Calyptraea aperta (Solander). 

N ucula magnifica Conrad? 

Pteria sp. 

Pecten n. sp. 

Crassatellites protextus (Conrad) var. 

Astarte tellinoides Conrad? 

Venericardia alticostata Conrad var. 

Phacoides (Here) hamatus Dall. 

Phacoides alveatus (Conrad). 

Protocardia nicolleti (Conrad). 

Pitaria P,erovata (Conrad). 

Cytherea sp. 

Psammobia sp. 

Panope porrectoides (Aldrich). 

Corbula oniscus Conrad. 

1 Veatch, Otto, and Stephenson, L. W ., op. cit., p. 295. Identified by 

T. W. Vaughan; list revised by C. W. Cooke. 

LITTLE KEG CREEK. 

A large collection of fossils that is especially 

interestinO' because it shows the intimate 0 

relationships of the Claiborne and Jackson 

faunas was obtained on the east side of Little 

Keg Creek, 7 miles north-northwest of Sandersville. Without the knowledge of the extended 

range of certain species acquired since the 

publication of the report on the Coastal Plain of 

Georgia, this assemblage of forms would have 

been unhesitatingly referred to the upper 

Claiborne. As it stands, the numerical .proportions of Claiborne and Jackson species 

recognized are practically the same, and the 

discovery of one or two additional species 

might turn the scale to one side or the other. 

When the numerical evidence is inconclusive 

in determining the age . of a fauna, the philosophic course appears to be to attribute greater 

siO'ni:fi.cance to the initial appearance of new 

fo~ms than to the survival of old species. According to this reasoning the fauna at Keg 

Creek is lower Jacksonian, and it is so considered in this report. · Moreover, this correlation is in accordancJ with that deduced from 

other stratigraphic criteria. , 

Section on east side of Little Xeg Creek, Washington County, 

7 miles north-northwest of Sandersville. 

Eocene: 

4. Coarse red sand with a few small quartz pebbles· 40 feet above the base is a 10-foot bed 

of white sand and yellow and white clay .. 

3. Greenish plastic clay ...................... . 

2. Coarse red sand grading into overlying bed. 

Fossils very abundant but restricted to 6 

inches at bottom .............. ' ......... . 

Unconformity (altitude 360 feet above sea level). 

Cretaceous: 

1. White sand with lenses of kaolin, to level of 

creek ................................... . 

Feet. 

100 

6~ 

60 

The fossils in the following list were collected 

from the base of bed 2, which is a local pocket 

filling a hollow in the Cretaceous surface. 

Station 7707. Roadside east of Little Keg Creek, 7 

miles north-northwest of Sandersville. Immediately 

above the Cretaceo;us. Cooke and Shearer, collectors, 

1916: 

CJ Flabellum cuneiforme Lonsdale. 

J Astrhelia burnsi Vaughan. 

Astrhelia sp. 

Volvula sp. 

CJ Actaeon idoneus Conrad. 

Actaeon sp. 

Terebra sp. 

C Cochlespirella nana (Lea)? 

Turritidae, 3 sp. 
DEPOSITS OF CLAIBORNE AND JACKSON AGE IN GEORGIA. 49 

Station 7707-Continued. 

OJ Conus sauridens Conrad. 

OJ Cancellaria gemmata Conrad. 

Cancellaria, 2 sp. 

Olivella sp. 

C Ancillina scamba (Conrad). 

CJ Marginella semen Lea. 

Conomitra sp. 

J Psilocochlis mccalliei (Dall). 

Caricella n. sp. 

OJ Plejona petros~ (Conrad). 

OJ Lapparia pactilis (Conrad). 

Below is given a systematic outline of the 

stratigraphy of the deposits of Claiborne and 

Jackson age as it is interpreted in the light of 

the new evidence. 

STRATIGRAPHY OF DEPOSITS OF CLAIBORNE 

AND JACKSON AGE IN GEORGIA. 

DEPOSITS OF CLAIBORNE AGE. 

FORMATIONS INCLUDED. 

Fusinus sp. The Claiborne group receives its name from 

Clavilithes sp. Claiborne Landing, Alabama River, Ala., the 

OJ Levifusus trabeatus (Conrad)? site of a town formerly of considerable impor- C Phos sagenus (Conrad). 

c Terebrifusus amoenus (Conrad). tance but now almost deserted. In the type 

J Ficus filius (Meyer). region the group is divided into three formaCJ Calyptraphorus velatus (Conrad). tions, the lowest being the Tallahatta buhrCerithiopsis sp. stone, the middle the Lisbon formation, and 

OJ Turritella carinata Lea. the upper the· Gosport sand. The correlations 

OJ Mesaliavetusta (Conrad). Epitonium sp. between Alabama and Georgia are not precise 

Turbonilla sp. enough to justify the use of_ any of these formaJ Sinistrella americana (Aldrich)? tion names in Georgia. ' 

Calyptraea sp. According to the interpretation of Veatch 

OJ Lunatia minima (Lea). and Stephenson, nearly all the deposits of 

Neverita sp. OJ Dentalium sp. Eocene age in Georgia were included in the 

OJ Nucwa magnifica Conrad? Claiborne group, and their map shows ClaiCJ Nucula ovula Lea. borne formations extending across the entire 

OJ Leda multilineata Conrad. width of the State. They recognized two forCJ Glycymeris staminea (Conrad). mations within the group-a lower, the McBean 

Glycymeris sp. f 

c Crenella isocardioides (Lea). ormation with the so-called Congaree clay . 

OJ Corbula oniscus Conrad. member, and an upper, the Barnwell sand. 

CJ Corbula densata Conrad. The recent detailed field studies of Shearer 

C Corbula alabamiensis Lea. and Brantly have shown that the so-called 

C Corbula fossata var. extenuata Dall. "Congaree clay member of the McBean formaCJ Pitaria perovata (Conrad). f 

OJ Pitaria mortoni (Conrad). tion" properly constitutes part o the Ba:rnCJ Miltha pandata (Conrad)? well formation, and studies of the fossils by 

OJ Lucina subvexa Conrad? Cooke, as set forth in the preceding part of 

OJ Phacoides alveatus (Conrad)? this paper, have shown that the residue of their 

Astarte cf. A. tellinoides (Conrad). McBean formation in central Georgia also be~ 

OJ Crassatellites protextus (Conrad) var. longs to the Barnwell. The paleontologic eviJ Crassatellites n. sp.? 

J Protocardia nicolleti (Conrad). dence also indicates that the Barnwell formaCJ Venericardia planicosta (Lamarck). tion is of Jackson rather than of upper Claiborne 

J Venericardia sp. (small). age, as previously supposed, and this conclusion 

OJ Venericardia alticostata Conrad var. is corroborated by diastrophic and other 

Sufficient evidence has been advanced in the stratigraphic criteria. 

preceding pages to show, first, that certain As restricted by the elimination of the Barnstrata referred by Veatch and Stephenson to well formation and parts of the McBean 

the McBean formation overlie limestones that formation the outcropping strata of Claiborne 

are definitely of Jackson age and, second, that age in Georgia are confined to two separate 

the fauna of the Barnwell formation appears to areas-a small irregular area in the valleys of 

be more closely related to Jackson than to McBean Creek and Savannah River, in the 

Claiborne faunas and that the fossiliferous beds extreme eastern part of the State, ·and a long, 

at some places lie directly upon Lower Cre- [ narrow strip in western Georgia, extending 

taceous strata. from Chattahoochee River eastward to a point 
S.HORTElt CONTRIBUT'IONS TO GENERAL GEOLOGY, 1918. 

a few miles beyond Flint River. In the ina..i J -. termedia te region the 

en g Claiborne deposits are >-l 

C1J 

.S 

overlapped by strata of 

Jackson age. Th~ beds 

of Claiborne age in the 

Savannah area retain 

the name McBean formation, but those in 

the ChattahoocheeFlint River area, which 

were included by Veatch 

and Stephenson in the 

McBean formation and 

Barnwell sand, will be 

design a ted in this report 

undifferentiated Claiborne. The areal distribution is shown on the 

geologic rna p (Pl. VII). 

McBEAN FORMATION. 

NAME. 

The McBean formation was named by 

Veatch and Stephenson 1 from the town of 

McBean, in Richmond 

County, Ga., and from 

McBean Creek, which 

forms the boundary between ·Richmond and 

Burke counties. 

STRATIGRAPHIC RELATION'S. 

The McBean formation rests unconformably upon the Lower 

Cretaceous strata and is 

overlain by the Barnwell 

formation. The contact 

with the Barnwell is 

obscure, but it appears 

probable that there exists at least local unconformity between the 

two formations. 

In the Savannah area 

~ * ~ ~ 2 ~ ~ the Claiborne s t rat a · ;:.. 

~ have been overlapped by · 

~ the Barnwell formation, 

though probably not so much as farther west, 

1 Op. cit., p. 237. 

but the valley of Savannah River has been 

incised so deeply that the overlapping portion 

of the Barnwell formation has been cut away 

along the river far enough to expose the McBean 

in its proper position above the Cretaceous. 

(See section, fig. 7.) 

LITHOLOGIC CHARACTER AND THICKNESS. 

The McBean formation - consists chiefly of 

gray marl or sandy limestone and yellow sand 

with a little lignitio matter and greenish olay. 

The greatest thickness thus far observed at 

one locality is not more than 80 feet, and the 

total stratigraphic thickness along the outcrop 

in Georgia probably does not greatly exceed 

100 feet. · 

PALEONTOLOGIC CHARACTER. 

A large collection of well-preserved shells, 

chiefly mollusks, was obtained by Earle Sloan 

on the south side of McBean Creek near the 

Augusta-Waynesboro road. On the basis of 

these shells ) Vaughan 2 correlat~s the strata 

with the Lisbon formation of Alabama and 

Mississippi, the St. Maurice formation of Louisiana, and the Cook Mountain formation of 

Texas. The same fauna has been found at 

several localities in Aiken and Orangeburg 

counties, S. C. The following list of species 

from Sloan's Scarp, McBean Creek, is quoted 

from the report on the Coastal Plain: 3 

Endopachys maclurii (Lea). 

Ringicula biplicata (Lea). 

Conus sauridens Conrad. 

Pleurotoma kelloggi Gabb. 

Pleurotoma texacona Harris. 

Pleurotoma terebriformis Meyero 

Pleurotoma childreni Lea. 

Pleurotoma lesueuri Lea. 

Pleurotoma; nodocarinata Gabb. 

Pleurotoma aff. P. rugosa Lea. 

Amblyacn:m stantoni Vaughan. 

Amblyacrum huppertzi var. penrosei Harris? 

Mangelia infans Meyer. 

Marginella columba Lea. 

Marginella semen Lea. 

Caricella demissa var. texana Gabb. 

Caricella aff. C. pyruloides (Conrad). 

Clavelithes humerosus Conrad. 

Fusus bellus Conrad. 

Fusus mortoni Lea. 

Lirofusus thoracicus (Conrad). 

Typhis gracilois Conrad. 

Pyrula (Fusoficula) texana Harris. 

Leiorhynus prorutus Conrad. 

Laevibuccinum prorsum Conrad. 

Mitrella mississippiensis Meyer and Aldrich. 

2 Idem, p. 240. 3 Idem, pp. 239-240. 
u. GEOLO<J"ICAL SURVEY 

<( 

CD 

....I 

Base from U. S. Geol oeical Survey 

1:1,000,000 scale ma p of the United 

States now in prepa ration 

F 

0 

L 0 R D A 

84° 88° 

GEOLOGIC MAP OF PART OF THE COASTAL PLAIN OF GEORGIA 

120 PLATE II 

0 

..... 

St:~unol :-... 

< 

~ 

>..1 

f-. 

'<t; 

From ~reolo~ric map by T. Way land Vauehan, 

L. W. Stephenson, and Otto Veatch, with 

modifica tions by C. W. Cooke and H. K. Shearer 

I 

J 

(' 

I 

I 

I 

LEGEND 

SEDI MENTARY ROCKS 

cala limestone Barnwell f ormation 

(Wh i te "''"'"'tla" linuuto•~: (Ch.i<1f!v red ll<ttltU nnd uel<owi.!h. dtlv• 

Jtu:kMmfo81JiUJ) with chert beti<; Jacksonfo81Jil1l) 

Undifferentiated Claiborne 

(Sand nnd calcttreou8 mcu-t.) 

UNCONFORMITY 

Wilcox formatio n 

(Stlnda. cl~tu•. and •heU marls) 

UNCONFORMITY 

_l 

Midway formation 

McBean formation 

(Calcar~mtJI marl, 1'mpure litn.t1Jto'1:.-e, 

mnd. nn<l dtlv: Cia ibono• fotlttiltJ) 

(Stlndo, cla11•. marls, and limuto><u) 

UNCONFORMITY 

Upp" clays, C• '""'"' 

and marls 

•••d•, 1 

r <( 

~ (Ri pley and r<:utaw formations) t;; and Lower Cretaceous arkosic 5 sands, sanrly clays, and pure whi te clays J 

IGNEOUS ROCKS 

CrystA.lline rocks 

z 

~ 0:: 

m 

~ u 

w 

0:: 

Q.. 

>-

0:: 

<( 

f: 

0:: 

UJ 

1-
I 

DEPOSITS OF CLAIBORNE AND .JACKSON AGE IN GEORGIA. 51 

Phos sagenum (Conrad). 

Buccinanops altile (Conrad). 

Pseudoliva vetusta (Conrad) 

Lacinia alveata Conrad. 

Turritella nasuta Gab b. 

Turritella nasuta var. houstonia Harris. 

Turritella arenicola Conrad. 

Turritella carinata Lea. 

Mesalia claibornensis (Conrad). 

Tuba antiquata Conrad. 

Amalthea pygmaea (Lea). 

Calyptrea aperta (Solander). 

Crepidula lirata Conrad. 

Lunatia eminula (Conrad). 

Natica semilunata Lea. 

Sigaretus declivis Conrad. 

Solarium elaboratum Conrad (young). 

Solariorbis depressa (Lea) var. 

Dentalium annulatum Meyer. 

N ucula ovula Lea. 

Nucula magnifica Conrad. 

Leda media Lea. 

Y oidia psammotaea Dall. 

Area rhomboidella Lea. 

Ostrea sellaeformis Conrad. 

Pecten wahtubbeanus Dall. 

Crassatellites protextus (Conrad). 

Venericardia sp. (also at Lisbon, Ala.). 

V enericardia al ticostata (Conrad). 

Venericardia planicosta Lamarck. 

Phacoides papyraceus (Lea). 

Bornia prima (Aldrich). 

Cytherea discoidalis Conrad. 

Metis raveneli (Conrad). 

Tellina mooreana Gab b . 

Pteropsis lapidosa Conrad. 

Corbula alabamiensis Lea. 

Corbula densata Conrad. 

Corbula fossata var. extenuata Dall. 

AREAL DISTRIBUTION, PHYSIOGRAPmC EXPRESSION 

AND STRUCTURE. 

So far as known, exposures of the McBean 

formation in Georgia are confined to Richmond and Burke counties, forming a narrow 

strip along Savannah River north of Griffin's 

Landing, 16 miles below Shell Bluff, and covering the southern half of Richmond County in 

and north of the valley of McBean Creek. In 

general, the formation is too thickly covered 

by younger strata to have exerted much influence on the topography, but along the streams 

in the southern part of the area the harder 

ledges of limestone form prominent bluffs. 

No irregularities have been ·detected in the 

structure of the McBean formation. The 

upper surface of the forn1ation sl.opes evenly 

seaward at the rate of about 10 feet to the mile, 

and the underlying beds evidently have a 

slightly steeper dip. 

UNDIFFERENTIATED CLAIBORNE DEPOSITS. 

The Claiborne deposits in western Georgia 

are best exposed in the bluff on Chattahoochee 

River at Fort Gaines and in the Danville Ferry 

bluff on Flint River, 16! miles east of Americus. 

In the intermediate region the formation is thin 

and poorly exposed. Along Chattahoochee 

River Langdon 1, distinguished a lower "buhrstone" and an upper calcareous member of 

the Claiborne, but the division has not been 

recognized farther east. 

Between 'Flint and Chattahoochee rivers the 

Claiborne rests upon the Wilcox formation, 

from which it is separated by an erosion unconformity, which has been observed at Fort 

Gaines and at Cuthbert. The Claiborne deposits are overlain unconformably by red 

argillaceous sand of undetermined age, which 

greatly resembles contiguous beds in the 

Claiborne and is with difficulty distinguished 

from them. 

DEPOSITS OF JACKSON AGE. 

FORMATIONS INCLUDED. 

Two forn1ations of Jackson age occur m 

Georgia-the Barnwell formation, including 

the Twiggs clay member, and the Ocala limestone, including the Tivola tongue. These are 

partly_ equivalent in age but are very different 

in lithology and present different faunal facies. 

The Ocala limestone underlies a large part of 

Florida and southern Alabama and a considerable area in the southwester_n part of Georgia. 

The Barnwell formation extends from Houston 

County, Ga., beyond Savannah River an unknown distance into South Carolina. 

The Ocala limestone and the Barnwell formation interfinger and merge laterally into each 

other, but an arbitrary line drawn at the DoolyHouston county line delimits fairly well the 

main bodies of the formations. However, the 

Twiggs clay member of the Barnwell formation 

extends southward a short distance into the 

Ooala area and a bed of bryozoan-bearing limestone, which will be referred to as the Tivola. 

tongue of the Ocala limestone, projects as far 

north as Rich Hill, Crawford County, and forn1s 

an important horizon marker near the base of 

the Barnwell formation in Houston, Twiggs, 

and adjacent counties. 

1 Langdon, D. W ., Geology of the Coastal Plain of Alabama, pp. 744-

745, Alabama Geol. Survey, 1894. 
52 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

BARNWELL FORMATION. 

NAME. 

succeeded by calcareous beds containing in their lower 

portion large numbers of Ostrea georgiana, these beds in 

turn being overlain by red sands, the typical Barn.well 

Mr. Vaughan informs the present writers buhr sand of Sloan. 

that he made a trip with Mr. Sloan into Barn- Inasmuch as the name Barnwell, as used by 

well County, S. C., for the special purpose of Veatch and Stephenson, was restricted to devisiting the type locality of the Barnwell forma- posits composed almost entirely of sand, they 

tion, and that he incorporated the results of employed the appropriate formational name 

observations made at that time in the follow- Barnwell sand. For this is substituted, in the 

ing paragraph in the report by Veatch and present paper, the name Barnwell formation, 

Stephenson: 1 which is applied to a less homogeneous comMr. Earle Sloan2 has used the name Barnwell "buhr posite of materials, including, in addition to the 

sands" or Barnwell "phase" for red ferruginous sands Barnwell sand of Veatch and Stephenson, their 

~hat i.mmediately overlie the McBean formation as de~~d j so-called '' Congaree" clay and the Ostrea 

m this report. The type area of the Barnwell sand IBm georgiana zone of their McBean formation. 

Barnwell County, S. C., where its stratigraphic position 

is as stated. Sloan, who has also studied the area in 

Georgia adjacent to Savannah River, states that the Barnwell ' 'phase " is represented by the sands that overlie the 

fossiliferous marls of Shell Bluff. As there are sands of 

lower stratigraphic position but very sinrilar in appearance 

to the Barnwell, Sloan, in several instances, confused the 

lower horizon with his Barnwell. A notable instance of 

this confusion is seen in his referring to the Barnwell the 

fossiliferous sands near Hixon's bridge on Tinker's Creek. 3 

The horizon of the fossils of this exposure is far down in the 

McBean formation. However, it is evident that Sloan 

intended this name to apply to the red ferruginous sands 

of the upper horizon and not to those of the lower. He 

has orally given the information that he has found TurritellacarinataLeain the Barnwell sand in Barnwell County, 

S. C., and he is positive in his opinion that in the type area 

there is similarity in stratigraphic position and in both 

lithologic and faunal characters with the fossiliferous red 

ferruginous sands overlying the McBean formation in 

Burke County, Ga. 

Although no specific locality is mentioned by 

Sloan in either of his papers cited as the type 

of his "Barnwell buhr sands," it is evident 

that he had in mind the higher horizon which 

" irregularly overlaps the upper margin of the 

Santee marls." 4 

The stratigraphic succession in western 

South Carolina, according to V aughan,5 is as 

follows: 

At the base are silicified clays, fuller's earth, the Congaree shales of Sloan; these are overlain by glauconitic sandy 

marls, locally with silicified shells and . buhr rock, and 

calcareous beds, the Cawcaw shales and marls of Sloan, 

which are equivalent to his Warley Hill marl, Santee marl, 

and Mount Hope marl of the Santee area and which are 

1 Geology of the Coastal Plain of Georgia, p. 285, 1911. 

2 Handbook of South Carolina, pp. 86, 90, Columbia, S. C., Dept. Agr ., 

Commerce, and Immigration, 1917; Catalogue of the mineral localities 

of South Carolina, pp. 449, 460, South Carolina Geol. Survey, 1908. 

3 Catalogue of the mineral localities of South Carolina, pp. 268, 460. 

4 Handbook of South Carolina, p. 90. 

6 Index to the stratigraphy of North America: U. S. Geol. Survey 

Prof. Paper 71, p. 737, 1912. 

TWIGGS CLAY MEMBER. 

Extensive deposits of fuller's earth grading 

into calcareous clay of similar properties, which 

Veatch and Stephenson regarded as forming 

part of the :McBean formation and which they 

designated the ' ' Congaree cia y mem her of the 

McBean formation," have been found to occupy 

a much higher stratigraphic position than the 

Congaree shales of Sloan in South Carolina, 

with which they were correlated but which 

underlie the South Carolina equivalents of 

the McBean forma tion3 and to be of Jackson 

age. These deposits are characteristically 

developed in Twiggs County, and for that reason they are here named Twiggs clay member. 

Exposures near Pikes Peak station, on the 

Macon, Dublin & Savannah Railroad, are regarded as typic a 1. The Twiggs cia y is treated 

here as a member of the Barnwell forma.tion. 

STRATIGRAPHIC RELATIONS. 

In the Mississippi embayment, according to 

Berry,6 the last third of Claiborne time was 

marked " by a greater or less emergence of land, 

which was followed at the beginning of Jackson 

time by a pronounced transgression of the sea. 

Similar conditions appear to have prevailed in 

Georgia east of Flint River. The recession 

during late Claiborne time in Georgia is more 

or less conjectural, but the theory of transgression in Jackson time is supported by unequivocal evidence. The Jackson sea crept 

far inland up the drowned valleys of the old 

Claiborne land area, across the beveled edges 

of the lower Eocene and Cretaceous strata, 

s Berry, E. W., Erosion intervals in the Eocene of the Mississippi 

embayment: U.S. Geol. Survey Prof. Paper 95, p. 82, 1915. 
DEPOSITS OF CLAIBORNE AND JACKSON AGE IN GEORGIA. 53 

until its waves beat in places upon the crys- becomes calcareous and merges into limestones 

talline rocks of the Piedmont. The transgres- of the Ocala, and in the east, where it merges 

sion of the sea that took place during Barnwell into marl and oyster-shell beds of the Barnwell 

time appears to have been followed, in eastern formation. Along the northern margin of the 

Georgia, at least, by a slight emergence of the outcrops the clay member is overlain with 

land which thrust back the Vicksburg shore slight unconformity by red sands that apparline. At a subsequent period, perhaps dur- ently belong also to the Barnwell formation. 

ing the Miocene epoch, the sea again ad- This unconformity is exposed at Pikes Peak and 

vanced but did not attain its former maxi- Grovetown, but it evidently represents a withmum extent. drawal of the sea for only a short distance and 

FIGURE 8.-Diagram showing the relations between the Ocala limestone and the Barnwell formation. 

The Barnwell formation rests with at least 

local unconformity upon the McBean formation or, where that is absent, unconformably 

upon older strata. The relations of the Barnwell formation to the overlying strata are less 

obvious. On account of the similarity in appearance of much of the Barnwell to younger 

deposits of various ages, it is in many places 

difficult to distinguish between them or to be certain of the identity of the overlying formation. 

The Twiggs clay member occupies a position 

at the base and n~ar the landward margin of 

the Barnwell formation. Although the conditions of deposition were such that the fuller's 

earth and clays of similar character occur as 

lenses and discontinuous beds, exposures are 

N. 

Rich Hill Fort V.-illey 

feet l Barnwell formation · ! -- _:~~ggs clay member-of Barnwell format•on 

Crystalline rocks 

0 

for a short period of time, because farther south 

the clay member is conformable with the remainder of the Barnwell formation. In the 

regions north and also east of Wilkinson County, 

where the Ocala limestone is absent, the clay 

rests directly upon the surface of the Lower 

Cretaceous or is separated fromit by only a 

thin bed of sand; at a few places lobes of the 

clay member overlap the Cretaceous beds entirely and rest upon the crystalline rocks of the 

Piedmont area. The most notable of these 

overlaps are at Roberts and Grovetown. 

The Barnwell formation appears to have 

been laid down at nearly the same time as the 

Ocala limestone but in a part of the sea supplied more abundantly with sand and mud, and 

s. 

Byrom.W!e 

! Gum Creek 

1 

10 15 Miles ~--~----~----~ 

FIGuRE 9.-Section from Rich Hill, Crawford County, to the mouth of Gum Creek, Crisp County, Ga. 

abundant in a belt extendingfromDoolyCounty the lateral transition from the siliceous sedito Columbia County, more than halfway across ments of the Barnwell to the limestones of the 

the State. The mode of origin of the Twiggs Ocala is gradual. The Tivola tongue of the 

clay and the agencies that produced its peculiar Ocala limestone, which intrudes far into the 

physical properties are not clearly understood, main area of the Barnwell, represents a ternbut its situation indicates that it may have been porary invasion of the calcareous phase of deformed in long, narrow lagoons or bays to which position beyond its usual limits. The supposed 

coarse sediments had only occasional access but relations between the Barnwell formation and 

which appear to have had free cornmunication the Ocala hmestone are shown in the accomwith theopenseain the southwest, where the clay panying diagram (fig. 8) and section (fig. 9). 
54 SHOR.TER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

·At the base of the-Barnwell formation along 

S~vannah River is a -bed of impure limestone 

or ·marl that contains large numbers of shells 

of Ostrea georgiana Conrad, a huge oyster, some 

specimens of which attained a length of nearly 

2 feet. This species appears in eastern Georgia 

to be restricted to the lower part of the Barnwell 

formation. The Ostrea georgiana zone has been 

traced .for miles into South Carolina, and it 

seems probable that this zone represents a 

tongue of the Cooper marl of South Carolina 

and that it is continuous beneath the cover of 

younger deposits in southeastern Georgia with 

the Ocala limestone of Georgia and Florida. 

Local oyster beds that app~ar to oecupy the 

same stratigraphic position as the bed on 

Savannah River have been seen as far west as 

Danville. · LITHOLOGIC CHARACTER. 

The greater part of the Barnwell formation 

is sandy,' comprising widespread deposits of 

coarse brilliant-red sand which appears to 

derive its color from weathered glauconite, 

together with locally indurated beds of gray 

sandstone which in places approaches quartzite in texture, and basal conglomerates resembling the gravels of the Pleistocene terraces. The sand in many localities incloses 

masses of flint, many of which are fossiliferous 

and appear to represent the silicified remnants 

of lin1estone lenses. Some of the flint is in 

scattered lumps, but most of it is restricted to 

well-defined zones. . 

The Twiggs clay member of the Barnwell 

consists typically of greenish-gray siliceous clay 

of low specific gravity, not plastic but breaking 

with a hackly fracture and exhibiting all the 

properties of fuller's earth. The fuller's earth 

grades laterally into calcareous clay of similar 

appearance and properties and thence into 

argillaceous limestone. Some of the clay is 

free from grit, but most of it is interbedded 

with thin layers of sand. 

At places where the fuller's earth was ·not 

. deposited and north of the limit of clay deposition beds of yellowish-green glauconitic sand 

extend to the base of the Barnwell formation. 

Near the base of the formation are local beds 

of lignite: shaly aluminous sandstone, quartzite, and completely silicified sandy limestone. 

THI9KNESS. 

In eastern Georgia the thickness of the Barnwell formation has not been accurately determined, because the contact with the overlying 

formations is uncertain. In the Shell Bluff section 65 feet belong to this formation. At Louisville, whichisabout 10milesfrom the CretaceousBarnwell contact, 100 feet of beds referred to the 

Barnwell formation are exposed from Rocky 

Comfort Creek up to the level of the town. In a 

deep well near Louisville the top of the Cretaceous is thought to have been reached at a 

depth of about 350 feet/ but this thickness 

probably includes some Claiborne strata in 

addition to the Barnwell formation. The available ovidence does not indicate a thickness 

greater than 200 feet for the Barnwell formation in eastern Georgia, and it may be considerably less. 

In Twiggs County the beds referred to the 

·Barnwell formation extend from. the surface of 

the Lower Cretaceous in the Dry Branch kaolin 

mines, at an altitude of 400 feet above sea 

level, to the tops of the higher hills in the 

vicinity of Pikes Peak, at an altitude of 625 

feet. The formation is little more than 200 

feet thick. 

In Houston County, as the Tivola tongue of 

the Ocala limestone thickens the Barn well formation becomes thinner, and only about 100 feet of 

the Ross Hill section may be referred to it. 

The Twiggs clay member attains its maximum thickness near Pikes Peak in Twiggs 

County, where fuller's earth occurs at two distinct horizons separated by a bed of greenish fossiliferous sand, the whole being 100 feet thick. 

In Houston County the 100 . feet of fuller's 

earth, calcareous clay, and sand of the Barnwell formation may be considered as belonging 

almost entirely to the Twiggs clay member. 

South of these counties the clay becomes thinner as the underlying Tivola tongue of the 

Ocalb. limestone thickens. To the northeast, 

also, the Twiggs clay beco:m:es thinner along 

the strike, and at few places in Jefferson and 

Columbia counties is it as thick as 20 feet. 

PALEONTOLOGIC CHARACTER . 

The fauna of the Barnwell formation has already been discussed at some length (pp. 42-49). 

In general terms, it is an assemblage of shallowwater or littoral species which inherited many 

elements from the preceding upper Claiborne 

or Gosport fauna but which includes a number 

of species not known from older deposits. 

' 1 McCallie, S. W ., A preliminary report on the underground waters of 

Georgia: Georgia Geol. Survey Bull. 15, p. 129, 1908. 
DEPOSITS OF CLAIBORNB AND 'JACKSON AGE IN GEORGIA. 55 

The Mollusca constitute · the ·dominant ele- To summarize this list, it may be noted that of the 26 

ment, being represented by nlimerous genera species found in Georgia 1 comes up from the Wilcox, 3 

d h occur in the St. Maurice, 8 occur in the Y egua, 10 in the and spec1es. Bryozoa are abun ant 1n w at Lisbon, and 8 in the Gosport, making 13 of the 26 that 

may be regarded as transition beds between occur in known Claiborne. One additional species occurs 

the Barnwell and laterally adjacent formations in the Green River of Wyoming. 

but are scarce in more ty.pical deposits. Corals SixoftheGeorgiaspeciesoccurin the Jackson. Although 

are represented by a few very prolific species, the Twiggs clay flora.is thus apparently more like the Claiborne flora of ,other areas than it is like the Jackson, two and echinoderms by P eriarchus pileus-sinensis features make this similarity more apparent than real. 

and Mortonella quinquefaria. The most signi- One is the fact that the continental deposits in Texas reficant vertebrate thus far discovered is the huge £erred to tlie Yegua, in which several of the Georgia species 

zeuglodon Basilosaurus cetoides, which is· par- reappear, are believed by me to be of Jackson age. The 

ticularly valuable as a guide fossil. second modifying factor is that the bulk of the known ClaiThe Twiggs clay member of the Barnwell borne florais found in the upper Claiborne and that this · upper Claiborne flora is but slightly modified in passing formation has yielded a small flora which as- over into the Jackson. · 

sists 1n correlating isolated exposures of the It should not be overlooked that 10 species, 

formation with one another but which presents or 38 per cent of the total number, have not 

inconclusive evidence for determining the age yet been found elsewhere and that subsequent 

of the deposits because the floras of the upper collecting may change the relative proportions 

Claiborne and lower Jackson are very similar. of Claiborne and Jackson species. The 26 

As originally described by Berry/ the flora · species of plants known to science out of the 

included only 17 species of plants, all of the~ hundreds that must have existed at the same 

new, but recent collections have increased the tiine form so insignificant a part of the flora 

total to 26, and most of them have since been that they ought not to be considered as necesdiscovered elsewhere. The following list wi~h sarily representative of the whole. :Moreover, 

comments has been furnished by Prof. Berryt as pointed out by Ulrich,2 paleobotanists are 

Flora of the Twiggs clay member of the Barnwellformatioh. prone to place disputed formations lower in the 

time scale than is indicated by the marine 

invertebrates, because the plants attain their 

greatest development during the emergent 

interval preceding the in traduction of the new 

marine fa una. 

P.. ~ ~ -d I ;:j s s 0 .::: . r:il So '"' . ~ . 00 .::: ..£>::: ..... .::: +" .:::-~ I>< r:il.~ .:::.~ '"' o+" 0 0 00 r:il 

..::; ;:j+" 0+" p.. 

~ ~ 00 s 

~ 0 r:il ~ ~ C!:J ~ -------------1---------, Acrostichum georgianum..... . . . . . . . . X X 

Arundo pseudogoepperti. . . . . . . . . X X X >f 

Carpolithus naJasoides ......... . Castanea claibornensis. . . . . . . . . . . . ................... . Cassia georgiana... . . . . . . . . . . . . . . . . . . . . . . . . . . ..... / .. Conocarpus eocenica............. . ... X X 

Cupanites nigricansa........... . . .. . Cinnamomum augustum........ . X D?donae~ viscoso~des.... . . . . . . . . X X ~ 

F~cus cla1bornen~Is.......... . . . . . . .. . Ficus newtoneus1s. . . . . . . . . . . . . . . . . . . . . . X ....... . Malapoenna sp. . . . . . . . . . . . . . . . . . . . .......... . Mimosites georgian us............. X X .... Momisia americana...... . . . . . . . . . X .. 1 .• 

Pestalozzites minor ..................... _ ... _ ...... . .Pisonia claibornensis .......... _ . ' ... _ X 

.Pistia claibornensis ......................... . ...... . Pteris inq uirenda...... . . . . . . . . . . . . . . . . . . X ....... . Potamogeton megaphyllus ...... . Rhizophora .eocenica ............ . .Sapindus georgiana ........ ,..... X X . -I-. .Sophora claiborneana... . . . . . . . . . X X Sophor~ wilco.xiana .. ·:......... . X X . -I-. Sphaentes cla1bornensis ......... . Terminalia phaeocarpoides. . . . . . . >f 

Thrinax eocenica..... . . . . . . . . . . . X X .... 

a Green River formation of Wyoming. 

AREAL DISTRIBUTION. 

The Barnwell formation extends in a broad 

belt fron1 Savannah River nearly to Flint 

River, but in the western half of this belt, the 

area lying west of Oconee River, the formation 

is intermediate in character between the typical Barnwell and the Ocala limestone, merging 

into the Ocala toward the south, or seaward, 

and toward the southwest. In the description 

by colinties the southwestern boundary of the 

formation is arbitrarily placed at the HoustonDooly county line, although the Twiggs clay 

member and perhaps also some of the overlying 

red sands extend for some distance south of this 

line, and a wedge of bryozoan-bearing limestone (the Tivola tongue of the Ocala limestone) projects into the Barnwell formation in 

Houston, Twiggs, and adjacent counties, and 

2 Ulrich, E. 0., Correlation by displacements of the strand line and 

1 Berry, E . W., The Upper Cretaceous and Eocene· floras of South the function and proper use of fossils in correlation: Geol. Soo. America 

Carolina and Georgia: U. S. Geol. Survey Prof. Paper 84, p. 129, 1914. Bull., vol. 27, p. 465, 1916. 
56 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

forn1s an important horizon marker near the 

base of the formation. (See map, Pl. VII, and 

section, fig. 8.) 

The Barnwell formation occupies considerable areas in Burke, Richmond, Jefferson, 

Glascock, Washington, Wilkinson, Twiggs, and 

I-Iouston counties and smaller parts of adjacent 

counties. The northern boundary is very 

irregular, the plain forming the surface of the 

formation having been deeply dissected by 

streams that have cut their valleys down into 

the Cretaceous strata, leaving promontories and 

erosional outliers of the Barnwell in the interstream areas. The southern boundary is likewise irregular, but in reverse order, having long 

salients extending down the river valleys. 

The Twiggs clay member in eastern Georgia 

is confined chiefly to the northern edge of the 

area occupied by the Barnwell formation, but 

toward the west its outcrop widens until it 

practically coincides with that of the formation 

as a whole. It is characteristically developed 

near Grovetown, Columbia County, and outcrops have been noted at short intervals from 

that locality to Rich Hill, in Crawford County. 

PHYSIOGRAPHIC EXPRESSION. 

The unconsolidated sands of the Barnwell 

formation have yielded readily to erosional 

agencies and, especially along the fall line, 

have been deeply trenched. The harder sandstones have resisted better and in a few places, 

as at Browns Mountain, form hills of considerable height. In most places the Twiggs clay 

member is overlain by beds of sand, but where 

not so protected it shows a tendency to form 

barren "washes" or grassy s:lopes. · 

STRUCTURE. 

The Barnwell formation strikes approximately northeastward . . 

From exposures along the Macon-Perry 

road (National Highway) in Houston County 

the slope of the Cretaceous surface is estimated 

at more than 12 feet but not more than 20 

feet to the mile. The dip of the Barnwell 

formation is a little less than that of the 

surface upon which it lies and is probably 

about 10 feet to the mile. 

In Twiggs County the slope of the upland 

plain is 9 feet to the mile measured. parallel to 

the Macon, Dublin & Savannah Railroad from 

Pikes Peak to Danville (southeast). The dii> 

of the Barnwell formation, · which is a little 

steeper than the slope of the plain, is probably 

between 10 and 15 feet to the mile. 

In the eastern part of the State the upper 

surface of the Lower :Cretaceous beds is very 

irregular, and the dip can not be stated with 

certainty. The base of the Barnwell formation in this region slopes from 500 feet above 

sea level at Grovetown to 80 feet at Griffin's. 

Landing, a fall of 420 feet in 36 miles, or a 

little more than 11 feet to the mile toward. 

the southeast. 

Except for the slight tilt toward the southeast the beds of the Barnwell formation are 

practically undisturbed. The only indication of later movements detected is a local 

anticline, cut through by the railroad at 

Pikes Peak, in which the limbs dip 4 ° SE. and. 

3° NW. 

OCALA LIMESTONE. 

NAME. 

In 1892 Dall 1 applied the name Ocala to 

limestone deposits exposed in the vicinity of 

Ocala, Marion County, Fla., and some years 

later the same author described a number of 

species of mollusks from the Ocala limestone 

and published a ·partial list of the species 

found in it. 2 This fauna was first recognized in Georgia by Vaughan, 3 who correlated 

the outcrops of limestone in Flint River near 

Bainbridge with the Ocala "zone," and the: 

name Ocala limestone was recently employed. 

by Cooke 4 in referring to the same deposits. 

The Ocala limestone as defined in this report 

includes the greater part of the ·vicksburg 

formation of Veatch and Stephenson 5 as well 

as most of the Jackson formation of the same 

authors. The Tivola tongue of the Ocala limestone is typically exposed at the quarry of 

the Planters Limestone Co., 2 miles south of 

Tivola. (See p. 76.) 

1 Dall, W. H., Correlation papers-Neocene: U.S. Geol. Survey RulL 

84, p. 103, 1892. 

2 Dall, W. H., Contributions to the Tertiary fauna of Florida, pt. 6: 

Wagnet Inst. Trans., vol. 3, pp. 1219-1654, 1903. 

a Vaughan, T. W ., A Tertiary coral reef near Bainbridge, Ga.: Science,. 

new ser., vol. 12, p. 873, 1900; The Eocene and lower Oligocene coral 

faunas of the United States: U. S. Geol. Survey Mon. 39, p. 31, 1900. 

• Coo!M, C. W., The age of the Ocala limestone: U. ·s. Geol. Survey· 

Prof. Paper 95, p. 110, 1915; The stratigraphic position and faunal asso--

ciates of the orbitoid Foraminifera of the genus Orthophragmina from 

Georgia and Flqrida: U. S. Geol. Survey Prof. Paper 108, pp. 109-113., 

1917 (Prof. Paper 108-G). 

~Veatch, Otto, and Stephenson, L. W ., op. cit., pp. 296-362. 
DEPOSITS OF CLAIBORNE AND .JACKSON AGE IN GEORGIA. 57 

STRATIGRAPHIC RELATIONS. 

The relations of the Ocala limestone to both 

the underlying and the overlying formations 

:are imperfectly known. At its northeastern 

limits the formation overhips upon older 

strata (see fig. 8, p. 53), and similar conditions 

may prevail toward the west, but whether 

the overlap extends all the way to Chattahoochee River is uncertain. At any rate, the 

Claiborne deposits are not completely overlapped in the west, as in central Georgia. 

The Ocala limestone is overlain by the 

Vicksburg formation, but the Vicksburg has 

been eroded so much that its original relations 

to the Ocala are very obscure. Where the 

two formations have been observed in contact 

:no evidence of physical break in sedimentation 

between them has been detected. In the 

·vicinity of Bainbridge the upper surface of 

-the Ocala is exceedingly irregular, having 

suffered considerably from degradational agen-

~ies, but how much this unevenness is due t o 

·solution and disintegration of comparatively 

recent date or to what extent it antedates 

-the deposition of the overlying beds is at pres-

·ent unknown. The Vicksburg in this region 

is apparently represented. mostly by scattered 

lumps of residual flint, the main overlying 

-formation belonging to the Apalachicola group. 

The following note is introduced through the 

-courtesy of Messrs. Vaughan and Bassler: 

In 1915 Vaughan 1 pointed out that a species of coral 

:referred to by him as Orbicella cellulosa (Duncan) is common to Vicksburg deposits at Vicksburg, Miss., to the 

basal Chattahoochee at Bainbridge, Ga., to the Tampa 

formation at Tampa, Fla., and to the Antigua formation 

--of Antigua. Recent unpublished results obtained by 

Vaughan from his studies of the corals and associated 

organisms in the base of the Chattahoochee formation 

.and in the Antigua formation of Antigua indicate that 

these deposits are of middle Oligocene age and that they 

are stratigraphically only a little above the upper Vicksburgian Byram calcareous marl 2 of Mississippi. Bassler 

has identified Bryozoa characteristic of the Marianna 

limestone (middle Vicksburgian) in chert found associated 

with the coralliferous chert in the vicinity of Bainbridge 

but not in the same chert masses as the corals. As the 

:Bryozoa and the corals have not been found together, 

they seem to represent different horizons. A considerable 

:number of mollusks occurring also at Vicksburg have 

been listed from these beds by Dall, 3 but a critical com~ 

parison of the faunas has not been attempted. 

1 Carnegie Inst. Washington Year Book 13, p. 360, 1915. 

2 Defined by C. Wythe Cooke in Correlation of the deposits of Jackson 

:and Vicksburg ages in Mississippi and Alabama: Washington Acad. 

Sci. Jour., vol. 8, pp. 186-198, 1918. 

a Dall, w. H., A contribut ion to the invertebrate fauna of the Oligocene 

beds of Flint River, Ga.: U. S. Nat. Mus. Proc., vol. 51, pp. 488-489, 1916. _ 

The Ocala limestone appears to have been 

deposited almost contemporaneously with the 

Barnwell formation, with which it is interbedded in the transition area. The Tivola 

tongue, which extends for many miles into the 

area occupied by the Barnwell, lies beneath the 

larger mass of that formation, but in most 

places is underlain by thin sandy beds that are 

classed with the Barnwell. 

LITHOLOGIC CHARACTER. 

The Ocala limestone consists chiefly of soft 

white or cream-colored limestone that in 

places is composed almost entirely of the re:.. 

mains of Foraminifera and Bryozoa. The 

lower portion is more arenaceous and in places 

approaches sandstone in composition. In the 

transition area at the northeastern extremity 

of the formation the Ocala beoomes highly 

argillaceous and merges into the Twiggs clay 

member of the Barnwell formation. 

On exposed surfaces at many localities the 

pores of the soft limestone have been filled up 

by infiltration of calcium carbonate, which has 

"case hardened" the outer layers of the rock 

into hard semicrystalline limestone. That 

processes of silicification have been active in 

certain regions is shown by large masses of 

white flint or silicified limestone that are strewn 

over the surface or embedded in residual sand, 

but such action has by no means been confined 

to the Ocala limestone, as it has attacked 

the Vicksburg and Chattahoochee limestones 

as well. 

TmCXNESS. 

Reliable data concerning the thickness of the 

Ocala limestone are lacking. In a well at 

Albany 4 the drill is believed to have entered 

the Claiborne at a depth of about 280 feet, and 

the total thickness of the Ocala in this vicinity 

probably does not greatly exceed 300 feet. 

At Bainbridge the drill penetrated 750 feet of 

limestone, but how much of this is of Jackson 

age is unknown. The Tivola tongue in few 

pla({es exceeds 40 feet in· thickness and is com-_ 

monly much thinner. 

PALEONTOLOGIC CHARACTER. 

The Ocala limestone contains a large and 

characteristic bryozoan fauna, of 'which about 

90 species have been found in Georgia. 5 

• Georgia Geol. Survey Bull. 26, pp. 317-318, 1911. 

5 Canu, Ferdinand, and Bassler, R. 8., manuscript list. 
58 SHORTER CONTRIBUTIONS TO GENE~~AL GEOLOGY, 1918. 

tremity the Ocala is interbedded with or transitional to the Barnwell formation. Northeast 

of this line the low& portion of the formation, 

the Tivola tongue, extends into the Barnwell 

area through Houston, Twiggs, and Bleckley 

counties, and parts of Wilkinson and Crawford· 

counties. Throughout much of its areal extent 

the formation is conGealed from view by a thin 

cover of younger_ strata, ~ainly sands, but it is 

exposed along ~atercourses, and its presence 

in the inte:r_strea~ . areas is indicated by lime 

sinks and fli:p.t boulders. 

PHYSIOGRAPmC EXPRESSION. 

Foraminifera are exceedingly abund~nt and 

in places constitute a large part of the rock, 

but lists are not yet available. The orbitoid 

Foraminifera are abundant, being represented 

by several species of Orthophragmina, both 

smooth and stellately marked, and also by 

species of Lepidocyclina. Species of both 

genera · have been erroneously referred to 

Orbitoides mantelli, which is the type species 

<?f the genus Lepidocyclina and appears to 

be peculiar to · the horizon of the Vicksburg 

represented by the Marianna limestone. Operculina is common in the middle or lower part 

of the formation. 

Echinodermata attained during Ocala time a The ready sohibility of the Ocala limestone 

greater development than during any other has assisted .in the degradation of its surface. 

part of the Tertiary period in the Atlantic and In the region lying between Flint and ChattaGulf Coastal Plain area. These forms appear ho?chee rivers-un<;lerground solution has 'been 

to be very much restricted in vertical range, e;tensiive, and the plain is dotted with lime 

and it seems probable that more detailed work sinks and ponds, ranging from shallow saucerwill result in the discrimination of several zones shaped circular depressions to sinks of considerby means of them. Periarchus pileus-sinensis able size. The region is a flat low-lying plain, 

appears to be restricted -to the Tivola horizon; in marked contr~st to the high sandy plateau 

other species, which occur higher in the forma- upheld by the Alum Bluff formation east of 

tion, are Oidaris georgiana, Laganum? crustu- Flint River. Small surface streams are not 

loides, Schizaster jloridanus, Macropneustes abundant, :m:u~h of the drainage going through 

mortoni, Oassidulus (Rhynchopygus) depressus, subterranean channels. 

Oassidulus (Pygorhynchus) conradi, Oassid'Uius In the northeastern part of the_area occupied 

(Pygorhynchus) georgiensis, Eupatagus caroli-:- by the Ocala limestone, solution appears· to 

nensis, Oliogopygus haldermani, and Agassizia have played a part in the formation of topoconradi. graphic forms subordinate to that of mechanA rather extensive molluscan fauna is con- ical agencie.s. The harder limestone ledges 

tained in the Ocala limestone, but compara- have resisted erosion better than the clay detively few forms have been preserved well posits with which they are interbedded, with 

enough for determination. A noteworthy ex- the result that the limestone stands out in 

ception to this is found in the pectens, which steep slopes or bluffs. 

occur in great abundance and are beautifully STRUCTURE. 

preserved. Pecten perplanus, a typically Jack- The Ocala limestone has not been studied in_ 

son species, is pres.ent, toge~h~;r with sev~ral sufficient detail to permit accurate determina-' 

closely relat~d. species or :arieties. Am~s~ur_n tion of its structure, and the scarcity of recogoc.alanum:, o~Iginall:y descn~ed from Flonda, IS nized horizon markers makes such determinaWidely distnbuted In Georgia. tion difficult. The formation as a whole apAREAL DISTRIBUTION. pears to be inclined very gently seaward at 

The Ocala limestone occurs at or near the 

surface over a broad belt ·lying chiefly in the 

drainage basins of Chattahoochee -and Flint 

rivers. (See geologic map, Pl. VII.) The belt 

crosses Chattahoochee River between Saffold 

and a point about 4 miles above the mouth of 

Flint River, an airline distance of nearly 30 

miles; thence it extends northeastward to the 

Dooly-Houston county line, but at that exthe rate of probably 10 feet to the mile. Gentle flexures may exist, but none have been_ 

detected. 

ECONOMIC GEOLOGY. 

The greater part of the workable limestones. 

and marl deposits of the Coastal Plain of Georgia pertain to the Ocrua limestone. These havebeen treated in detail by Brantly.1 

1 Brantly, J. E., Georgia Geol. Survey Bull. 21, 1916. 
DEPOSITS OF CLAIBORNE AND JACKSON AGE IN GEORGIA. 59 

SUMMARY. 

The differences between the interpretation 

of the stratigraphy of Georgia here offered and 

that of Veatch and Stephenson may be bri9fly 

summarized as follows: 

The deposits of Claiborne age, which they 

mapped as extending uninterruptedly across 

the entire width of the State, have been restricted to two areas, one along Savannah 

River and McBean Creek and the other between 

Flint and Chattahoochee rivers. The deposits 

of Claiborn·e age in the east retain the name 

McBean formation, but those in the west are 

called undifferentiated Claiborne. 

The Barnwell sand, which they regarded as 

of upper Claiborne age, is raised in the time 

scale and placed in the Jackson epoch with the 

name altered to Barnwell formation. The socalled "Congaree clay member of the McBean 

formation" is _ placed bodily in the Barnwell 

formation and, together with calcareous clays 

which were already correlated wit4 the Jackson formation, is renamed Twiggs clay member, the name Congaree being inappropriate 

because the clay is now known to be much 

younger than the typical Congaree shales 

Sloan. Those parts of their McBean formation left after the elimination of the undifferentiated Claiborne and the typical McBean 

formation are here included in the Barnwell 

formation. 

The littoral facies of the Barnwell fauna bears 

an exceedingly close relationship to the littoral fauna of the Gosport sand of Alabama 

but is transitional between that fauna and 

typical Jackson faunas and contains enough 

distinctive species to justify the reference of it 

to the Jackson epoch. The discovery of evidence of an extensive transgression of the sea 

upon the old land surface at the beginning of 

Barnwell time corroborates the reference of the 

formation to the beginning of a new stage 

rather than to the closing period of an old. 

The greater portion of the Vicksburg formation of Veatch and Stephenson is transferred 

to the Jackson epoc4, under the name Ocala 

limestone, and the Jackson formation of their 

usage is divided between the Ocala limestone 

and the Barnwell formation. The residue of 

the Vicksburg formation is left untouched for 

the present.. 

LOCAL DETAILS. 

McBEAN FORMATION. 

1fcBean.-Several sections along the south 

side of Mc.Bean Creek, southeast of MoBeari 

station, are given by Vaughan/ and locnJities 

farther upstH'eam are deseribed by Brai1tly.2 

These descriptions show that the McBean formation is variable within short distances. 

East of the Central of Georgia Railway the 

formation consists largely of sand, clay, and 

lignitic material, with marl only near the base 

of the section. West of the railway the nut.rl 

beds become much thicker, reaching a thickness of over 50 feet, all above creek level, on 

the Newton Palmer property. The two following sections are typical of the beds east and 

west of the railway: · 

Section on Newton Palmer property, McBean Creik, on west 

side of Central ofGeorgia Railway. 

[Measured by J. E. Brantly, op. cit., p. 46.] 

Barnwell formation (?): Feet. 

6. Concealed interval; sa;ndy soil on top of hilL . 34 

McBean formation: 

5. Soft white argillaceo:us "rotten" limestone.... 7 

4. Medium hard highly fossiliferous limestone; 

fossils poorly preserved.: ..... ·............. 2 

3. Soft, "rotten" to consolidated cream-colored 

argillaceous limestone. . . . . . . . . . . . . . . . . . . . . 45 

2. Blue glauconitic clay like fuller's earth. . . . . . 6 

1. Hard arenaceous fossilif.erous limestone .. '. . . . . 2 

Creek bed. 

96 

Section in gully on south side of McBean Creek, a quarter of 

a mile ~ast of the bridge on the Augusta-Savannah public 

road. 

[Measured by C. W. Cooke.) 

Barnwell formation (?): Feet. 

6. Brilliant red massive argillaceous sand, very 

coarse in lower portion ................... .' 20 

McBean formation: 

5. Coarse incoherent yellow sand; at the top a locally indurated ledge of friable white sandstone, which elsewhere is represented by 

carbonaceous sand ................... ~ . . . . 30 

4. Coarse ·quartz sand in a matrix of greenishyellow clay............................... 4 

3. Fine yellow sand, incoherent at top, argillaceous below, with patches of calcareous and 

carbonaceous, almost lignitic material. . . . . . 5 

2. Soft fine-grained sandy gray calcareous marl, 

with a few fragments of shells and some hard 

nodules.................................. 3 

1. Concealed interval to creek level, about...... 30 

92 

t Veatch, Otto, and Stephenson, L. W., op. cit., p. 242. 2 Brantly, J. E., Report on the limestones and marls of the Coastal 

Plain of Georgia: Georgia Geol. Survey Bull. 21, pp. 44--50, 1916. 
60 SHOR.TER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

In the bottom · of the gully at the second 1 Shell Bluif.-Shell Bluff, on Savannah River, 

locality were found a few fragments of fossil- 163 miles from the mouth of the river, is one 

iferous chert that were probably derived from of the classic localities in the study of the geolthe red sand, bed 6 of the section. The rela- ogy of the Coastal Plain of Georgia and South 

tions of the upper bed to bed 5 are somewhat Carolina and has been described by many geolobscure, but it seems probable that there is an ogists during the last century. The 140 to 150 

erosional unconformity between them. feet of beds exposed there have previously 

On the Waynesboro road, at the foot .of the been correlated with various formations ·from 

hill leading down to McBean Creek, a few frag- the Claiborne to the Vicksburg. In the report 

ments of shells were seen in yellow sand! on the geology of the Coastal Plain of Georgia 

apparently bed 3 of the preceding section. the whole series was referred to the Claiborne 

The shells are not disseminated throughout group, and the line of division between the Methe sand but are segregated into small patches· Bean formation and the Barnwell sand was 

of shell marl. ~his is probably the horizon placed at the top of the Ostrea georgiana zone. 

from which Sloan obtained the large collection However, Vaughan 1 says in that report: 

of fossils listed on pages 50-51. 

Silver Blu_(f.-The southernmost exposure of 

the Lower Cretaceous beds and the best section 

of the lower part of the McBean formation is 

seen at Silver Bluff, 27 miles by river below 

Augusta and 12 miles above Shell Bluff. 

Section at Silver Bluff, Savannah River. 

[Described by H. K. Shearer. Measured at west end of bluff on South 

Carolina side.) 

Recent: Feet. 

8. Soil; gray sandy loam..................... 2 

Eocene-McBean formation: 

The McBean formation includes two paleontologic horizons. The lower one * * *. is especially characterized by Pleurotoma nodocarinata Gabb, Turritella nasuta 

Gabb, Turitella nasuta var. houstonia Harris, Ostrea sellaeformis 0.:-nrad, Pteropsis lapidosa Conrad, and Corbulafossata Meyer and Aldrich. . 

A higher horizon is represented especially well along 

Savannah River, between Shell Bluff, upstream, and Griffin's Landing, downstream. Along this stretch of the river 

a prominent ledge, largely composed of Ostrea georgiana 

Conrad, forms the top of the McBean formation. Although 

this formation could be subdivided along Savannah River, 

it was found impracticable to extend the subdivision westward, for which reason the Ostrea georgiana bed is considered as constituting its upper portion. 

7. Coarse mottled argillaceous sand. . . . . . . . . . . . 6 

6. Lenticular mass of crumbly, sandy ironstained clay, somewhat like fuller's eai"th. 

Maximum thickness ...... _............... 6 The red sand overlying the Ostrea georgiana 

5. Coarse red and yellow cross-bedded eand .... 10 zone was called the Barnwell sand, which was 

4. Layer of sand cemented by limonite........ .1 then supposed to be of Claiborne age. Since 

Unconformity. the publication of the Coastal Plain report, 

Lower Cretaceous: B 1 h d fi d B however, R. S. ass er 2 as i enti e ryozoa 3. Laminated yellow and brown sandy clay, maximum.............................. 2 characteristic of the Jackson deposits from the 

2. Blue highly plastic clay free from grit....... 2. 5 Ostrea georgiana zone, and careful stratigraphic 

·1. Yellow-gray arenaceous clay· · · - -· · · · · · · · · · · 2. 5 work has resulted in the recognition of this 

31. 1 

The strata classed as Lower Cretaceous were 

slightly fo~ded prior to the deposition of the 

overlying material, but there is no evidence 

elsewhere of any considerable disturbance of 

the beds. The beds above the unconformity 

are believed to lie at the same horizon or a 

little lower than the marl beds of Claiborne 

age at Shell Bluff, but aa they were deposited 

very near the shore line they contain no calcareous material. If the correlation of these 

beds is correct, the Cretaceous surface dips 

beneath the river level near the mouth of 

McBean Creek. 

horizon in the Barnwell formation at numerous 

localities in central Georgia. 

The following generalized section at Shell 

Bluff is made up from the writers' notes and 

from sections previously published. 3 The Ostrea georgiana zone occurs only downstream 

from the boat landing, but the underlying 

beds are exposed in the steep part of the bluff 

above the landing. 

1 Georgia Geol. Survey Bull. 26, p. ~40, 1911. 

2 Oral communication. 

a For more detailed sections see Sloan, Earle, Catalogue of the mineral 

localities of South Carolina: South Carolina Geol. Survey, 4th ser., Bull. 

2, pp. 271-272, 1908. Veatch, Otto, and Stephenson, L. W., Georgia 

Geol. Survey Bull. 26, pp. 243-247, 1911. Brantly, J. E., Georgia Geol. 

Survey Bull. 21, p. 51, 1916. 
DEPOSITS OF CLAIBORNE AND JACKSON AGE IN GEORGIA. 61 

Generalized section at Shell Bluff. 

Barnwell formation: Feet. 

7. Apparently all red argillaceous sand to level 

of upland plain. The surface of the plain 

is covered by several feet of loose gray sand, 

but clayey sand for road building is obtained 

from shallow trenches along the roads...... 35 

6. Ostrea georgiana zone. The base of the oyster 

bed is 80 feet above zero water level in the 

river, and although exposures are not continous, oysters are found up to no feet above 

water level. The oyster ledge at the b~se of 

the zone contains very large shells in a matrix 

of yellowish sand. Above this is a bed of 

calcareous conglomerate containing quartz 

pebbles. Above the conglomerate bed the 

oysters are in a matrix of yellowish marl or 

hard calcareous clay, having some of the 

characteristics of fuller's earth. The matrix 

of the oyster shells contains Bryozoa of the 

Rich Hill facies of the Jackson fauna...... 30 

McBean formation : 

5. Concealed interval between the upper and 

lower bluffs. Covered by talus from the 

0 2trea georgiana zone and other overlying 

formations but probably is a bed of sand.. 10 

4. Moderately hard to hard light-colored marl, 

with few fossils ...................... ----- 9 

3. Ledge of hard brown coquina-like rock, with 

numerous hollow casts of fossils.... . . . . . . . . . 6 

2. White to purplish sandy limestone, made up 

largely of fossils. This is the most important 

fossiliferous stratum of the McBean formation, and Vaughan collected from it a total of 

35 species. It is characterized by large 

specimens of Ostrea sellaejormis............. 6 

1. Sandy and argillaceous marl, not abundantly 

fossiliferous; in layers differing considerably in color, hardness, and chemical composition. A number of analyses show calcium carbonate content ranging from 50 

to 90 per cent, but the actual local variation 

is even greater, for there are thin ledges of 

comparatively pure limestone and other beds 

of slightly calcareous sand and clay. The 

color, as a whole, appears light gray, but individual beds have various shades of white, 

yellow, buff, gray, and greenish yellow. 

This bed · is exposed as an almost vertical 

cliff, rising from water level, in which the 

harder layers form projecting ledges .... ·.... 50 

The 99-foot bench mark of the United 

States Army Engineers is situated near the 

base of the bluff, and low-water level in the 

river is reported to be 87 feet above sea level. 

The preceding section starts approximately 90 

feet above sea level and extends to an altitude 

of 235 feet, with the base of the · Barnwell at 

170 feet. 

On Savannah River downstream from Shell 

Bluff marl of the McBean formation is exposed 

28288°-·19---5 

at Demerie's Ferry, Hancock . Landing, Utley 

Point, and Blue Bluff and finally passes 

beneath water level at Griffin's Landing, where 

it is overlain unconformably by the Ostrea 

georgiana zone and calcareous fuller's earth. 

UNDIFFERENTIATED CLAmORNE DEPOSITS. 

Fort Gaines.-A complete section of the 

Wilcox and Claiborne formations is exposed in 

a high bluff along the Georgia side of Chattahoochee River at Fort Gaines and in the slope~ 

from the terrace on which the town is built up 

to the level of the upland plain. The sections 

given below show the character of the Claiborne 

in this vicinity. 

Section along road leading east from the Raymur Hotel, Fort 

Gaines. 

l Thicknesses approximate. Measured by L. W. Stephenson,t with comments by H. K. Shearer.] 

Age unknown: Feet. 

8. Coarse red ferruginous pebbly sand. (Similar 

material extends down the hill for some distance, probably creep.) Thickness to top 

of hill, half a mile from the hoteL... . . . . . . . 50 

Eocene: Undifferentiated Claiborne: 

7. Greenish sandy clays and argillaceous sands, 

more or less weathered and mottled ..... :.... 40 

6. Compact :fine greenish-gray sandstone, with 

fossil prints (fossils collected)............... 3 

5. Pale-green :fine loose sand ............ ~....... 3 

4. Compact :fine greenish-gray sandstone, with 

fossil prints (fossils collected)............... 3 

3. Light-green compact, finely arenaceous clay. 

A part of the bed is indurated, breaks with 

hackly fracture, and resembles the silicified 

fuller's earth of eastern Georgia ................ 7 

2. Fine green sandstone... . . . . . . . . . . . . . . . . . . . . . 3 

1. Greenish clays and sands, more or less weathered and mottled. . . . . . . . . . . . . . . . . . . . . . . . . • 65 

175 

The following fossil mollusks from beds 4 

and 6 were identified by T. W. Vaughan: 

Plejona sp. 

Turritella sp. 

Led a pharcida Dall? 

Venericardia planicosta Lamarck. 

Miltha claibornensis (Conrad). 

Cytherea sp. 

Solen lisbonensis Aldrich? 

The preceding section starts at an altitude 

of 225 feet above sea level, 15 feet below the 

level of the business section of Fort Gaines, 

which is on the second (upper) river terrace. 

The .following section is exposed in the bluff a 

quarter of a mile below the wagon bridge and 

1 Georgia Geol. Survey Bull. 26, p; 263, 1911. 
62 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

has its top at the edge of the terrace, at an altitude of 215 feet above sea level. 

Section of bluff at Fort Gaines. 

[Measured by Otto Veatch; descriptions revised by H. K. Shearer.] 

Pleistocene: 

9. Coarse red sand with pebbles in the 

· lower half; caps the bluff ........... . 

Eocene: 

Undifferentiated Claiborne: 

8. Drab fine-grained laminated clay with 

sand partings; has the appearance 

of fuller's earth but is not nearly so 

light and porous as the Twiggs clay, 

of Jackson age, and apparently has 

a more kaolinic base .............. . 

7. Yellow and grayish glauconitic sand. 

Locally it is oxidized and contains 

Feet. 

15 

8 

limonite-cemented crusts .......... 10-12 

6. Clay and sand, in part calcareous; 

consists of drab carbonaceous clay 

at base, sand in middle, and very 

sandy shell marl at the top . ...... . 

5. Indurated clay layer or drab claystone; contains fossils and is similar 

lithologically to the claystone east of 

the town of Fort Gaines. (See pre20 

ceding section)........ . . . . . . . . . . . . 2-2.5 

4. Grayish argillaceous sand ........... . 

3. Yellowish and gray quartz sand; contains calcareous sand nodules; 

small pebbles noted at the base; 

fossils X enophora, Venericardia 

6 

planicosta. .. .. . . . . . . . . . . . . . . . . . . . . 2-2.5 

Unconformity(?). 

Wilcox formation: 

2. Clay, in part carbonaceous; calcareous, and lignitic sand, etc ...... . 

Unconformity. 

Midway formation: 

1. Impure limestone, maximum ..... · ... 

39 

20 

124 

difference is shown at a locality on the Lower 

River Road, th;ee-quarters of a mile south of 

Fort Gaines, where there is an exposure of 85 

feet of drab clay which is in part massive and 

sandy, in part interlaminated with sand, and 

is not fossiliferous. The clay crops out between 180 and 265 feet above sea level and is 

thought to be of Claiborne age. 

Outhbert.-In the cuts on the Central of 

Georgia Railway west of Cuthbert two uncon-

. formities, believed to mark the top and bottom 

of the Claiborne, are exposed. The lower unconformity, at an altitude of 410 feet above sea 

level, is seen near the 121-mile post, 3 miles 

west of Cuthbert. 

Section 3 miles west of Cuthbert, near 121-mile post, Central 

of Georgia Railway. 

Undifferentiated Claiborne: Feet. 

5. Dark-red argillaceous sand with a few clay 

laminae . ................................. 14 

4. Fine graveL ............................. , ... 1 

Unconformity. 

Wilcox formation: 

3. Light-colored argillaceous sand, with laminae 

and beds 2 or 3 feet thick of clay like fuller's 

earth ........................ ~ .. ~ . . . . . . . . . 10 

2. Red argillaceous sand, with clay laminae... . . 30 

1. Blue and gray banded clay, with some sand 

laminae, dense, approaching kaolin rather 

than fuller's earth in properties............ 30 

85 

A second unconformity is exposed 1 mile 

farther east, in the cut near the 120-mile post, 

at an altitude of 460 feet. 

Section 2 miles west of Cuthbert, near 120-mile post, Central 

of Georgia Railway. 

, Oligocene: Undifferentiated Vicksburg: 

In this section the Claiborne beds occupy the : 

interval from 150 to 200 feet above sea level, 

and in the preceding section they extend from , 

225 to 350 feet, indicating a total thickness of I 

200 feet, only 25 feet of which is concealed. 

The top of the Claiborne has not been accurately located at this place, but-on the Edison 

road, half a mile southeast of Fort Gaines, the 

Claiborne is overlain unconformably by sand 

interbedded with purple and white mottled 

plastic clay at an altitude of 355 feet above sea 

level. 

2. Yellow plastic clay, partly laminated but with 

bedding much distorted by slump. Distributed through the clay are boulders and 

·irregular masses of chert, containing fossils, 

most of which are undeterminable, but the 

Vicksburg species Pecten poulsoni was 

recognized. . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . 10+ 

Unconformity. (The unconformity is very irregular 

within a vertical range of 5 feet and is 

marked locally by a layer of ferruginous 

sandstone 1 to 2 inches thick, or by a thin 

band of carbonaceous sand or clay.) 

Eocene: Undifferentiated Claiborne: 

1. Brown to yellow and red sand, a glauconitic 

sand more or less weathered, with local 

masses cemented by limonite.... . . . . . . . . . 5+ The Claiborne strata are exceedingly variable 

in composition in the vicinity of Fort Gaines, 

and their lithologic appearance at the town is 

completely unlike that a mile away. This 

Exposures between the two cuts show that 

the entire 50 feet of beds of the Claiborne consist of red sand, with only a few laminae of clay. 
DEPOSITS OF CLAIBORNE AND JACKSON AGE IN GEORGIA. 63 

BARNWELL FORMATION. 

BURKE COUNTY. 

The Barnwell formation in Burke County 

consists of calcareous clay and shell marl 

overlain by red sand oontaining ledges of 

fossiliferous chert. The Ostrea georgiana zone, 

which is characteristically developed at Shell 

Bluff (see pp. 60-61) and other localities on 

Savannah River, has been recognized also at 

several places in the interior. At Keys Mill, 

on Brushy Creek, in the northwest corner of 

Burke County, 3 miles northwest of St. Clair, a 

bed of Ostrea georgiana similar to that at Shell 

Bluff and apparently occurring at the same 

stratigraphic horizon is exposed in an excava .. 

tion near the mill dam. The section at this 

locality follows. 

Section at Keys Mill. 

Barnwell formation: Feet. 

5. Red argillaceous sand containing laminae of 

yellow plastic clay near the base and quartz 

gravel beds and a few fragments of chert 

near the top. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 

4. Coarse yellow sand, carbonaceous at the base.. 10 

3. Pale-green, somewhat calcareous hackly clay 

or fuller's earth containing thin beds and 

irregular pockets of sand. The contact with 

the oyster bed is sharp ................ ·. . . . 8 

2. Large shells of Ostrea georgiana in a matrix of 

hard white limestone with patches of greenporous to dense and vitreous red flint containing numerous poorly preserved fossils (Turritella, Periarchus, etc.). The bed is at least 

15 feet thick. 

Other notable outcrops of chert were found 

at the following localities: Waynesboro-Millen 

road 1 mile south of Waynesboro, altitude 260 

feet above sea level; Waynesboro-St. Clair road 

10 miles west of Waynesboro, altitude 335 

feet, ledge 5 feet thick; Waynesboro~ Hephzibah 

road 3.1 miles northwest of Waynesboro, altitude 285 feet, 1 foot of vitreous chert overlying 

5 feet of porous chert; Girard-Millhaven road 

2.1 miles southeast of Girard, altitude 220 ( ~) 

feet ; Girard-Millhaven road 7.3 miles southeast 

of Girard, altitude 220 ( ~) feet," fragments of 

white vitreous flint. , 

Chert beds exposed at · Johnsons Landing 

and Stony Bluff on Savannah River in or opposite Screven County, along the lower course of 

Brier Creek below Girard, and at the former 

site of Millhaven on Beaverdam Creek were 

mapped as Vicksburg in the Coastal Plain 

report but without very strong paleontologic 

evidence. Vaughan 1 later suggested that the 

rock at Johnsons Landing may be of Jackson 

age and stated that it contains Pecten perplanus, which is now considered diagnostic of 

the Jackson. 

ish clay. A few incrusting Bryozoa were 

found; other fossils are present but not determinable. Similar material is reported to 

extend to a depth of 70 feet. Thickness 

seen ........................... ______ .... . 

Recent investigations indicate that the main 

chert beds at all the localities cited are probably 

at the same geologic horizon as those exposed 

7 throughout Burke and Jefferson counties1. Concealed interval to ·level of the mill pond that is, near the top of the Barnwell forma-

(altitude 300 (?)feet above sea level) ..... . 

70 

5 tion-but chert of later age may be present at 

some of them. The upper surface of the 

Barnwell therefore dips below water level in 

Savannah River between Stony Bluff and the 

:mouth of Brier Creek, in Screven County. 

Outcrops of chert beds are abundant throughout Burke County. They range in altitude 

from about 300 feet above sea level in the 

northern part of the county, where they are 

found near the hilltops, to 200 feet or less in 

the stream beds of the southern part. N earlv 

all the chert appears to lie at practically thue 

same horizon (near the top of the Barnwell) 

and may be residual from one thin but persistent bed of limestone. 

The thickest and most extensive exposures 

are in bluffs along Rocky Creek (altitude about 

280 feet above sea level) near the Louisville 

road, 3.3 l!liles southwest of Waynesboro. The 

slope up to 20 feet above water level in Rocky 

Creek is covered with great blocks of soft and 

RICHMOND COUNTY. 

· · The Barnwell formation caps the hills north 

of McBean Creek, where it overlies the McBean 

formation, but in the absence of characteristic 

beds it is almost impossible to distinguish ·one 

formation from the other. In the vicinity of · 

Bath and in the western part of the county the · 

Barnwell contains at its base beds of indurated 

fuller's earth which directly overlie the Cretaceous. A long, narrow area of Barnwell beds 

caps the ridge between Butler and Spirit creeks 

l U. S. Geol. Survey Prof. Paper 71, p. 739, 1912. 
• 

64 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

and extends northwestward into Columbia 

County, where it overlaps· the Lower Cretaceous beds to the edge of the crystalline area. 

As fossils are very rare in all the formations 

of Richmond County, the mapping of the contacts must depend largely on lithology and 

topography. 

A good section of the lower beds of the Barnwell formation is exposed near a spring on the 

north slope of Mount Enon, an isolated remnant of the original plain, near the Dean's 

Bridge road, 14 miles southwest of Augusta 

and about 3 miles northeast of Bath. 

S ection on north slope of Mount. Enon . Eocene: Feet . 

Barnwell formation : 

8. Apparently all red sand to top of hill. 

Near the top are fragments of dense 

banded cherty sandstone. . . . . . . . . . . . . 60 

Twiggs clay member: 

7. Soft white fuller's earth ; as th e top of 

the bed is not exposed, the thickness 

are very interesting and important. The 

McBean formation is absent, and probably it 

never extended so far north. The calcareous 

beds found in the Barnwell farther south and 

west are here lacking, and the formation consists of beds of fuller's earth, clay shale, or 

lignite, lying directly above the Lower Cretaceous and overlain by red sand. An unconformity' between the clay member and the 

red sand was noted at several places and may 

be of general occurrence throughout the 

county, and there are indications of local unconformities within the red sand. As the beds 

are all of shallow-water origin, these unconformities may have been produced by very 

slight oscillations in the level of the land or by 

currents. ' 

Phinizy Gully.-The relations of the Barnwell strata to the Lower Cretaceous are well 

shown in a gully in the abandoned Augus.taWrightsboro public road, 1 mile northeast of 

may be greater than indicated __ . . . __ _ 

6. Argillaceous sandstone with abundant 

but poorly preserved fossils and 

rounded quartz pebbles an inch in 

maximum diameter. ................. . 

3 . Grovetown, on the Phinizy property. This 

locality is especially interesting because it 

furnished a large collection of Eocene plants, 

1 described by Berry/ and because the uncon5. Coarse yellow sand ............ . ..... . 

4. Light-drab claystone, with angular 

and conchoidal fracture on weather11 formity between the Cretaceous and the Eocene 

is so well exposed here. 

ing. Has a high Si0 2-Al20 3 ratio and 

is a silicified fuller's earth, exactly 

like that at Hatcher's Mill and at 

Wrens, Jefferson County. . . . . . . . . . . . . . 11 

3. Gray plastic clay............... . .. . .. 1 

Unconformity. 

Lower Cretaceous: 

2. Indurated sandy kaolin, or flint clay. 10 

1. Kaolinic sand, etc., not measured . 

97 

The altitude of the top of the hill is about 

400 feet. 

At Bath about 25 feet of indurated fuller's 

earth is exposed in the slope above the spring 

and bath house on the Walker property, and 

the bed is seen at several other places in the 

vicinity, but at Hepzibah, 6 miles farther · east, 

the fuller's earth beds ·are absent. In the pit of 

the Albion Kaolin Co. the Cretaceous kaolin is 

overlain by 100 feet of red and yellow argillaceous sand without any conspicuous clay beds. 

COLUMBIA COUNTY. 

The only Eocene deposits of Columbia 

County are several lobes that extend into the 

southern part of the ·qounty near Grovetown, 

Forrest, and Harlem, but some of the exposures 

S ection of Phinizy G11.lly, 1 mile northeast of Groveto'Wn. 

Eocene: Feet. 

Barnwell formation: 

6. Yellow to red argillaceous sand, 

coarse and pebbly near base. Caps 

hill to east of gully, to an altitude of 

540 feet................. . . . . . . . . . . . . 50+ 

5. Laminated plastic greenish clay. . . . 0-3 

4. Conglomerate of varicolored kaolin 

pellets in red sand. Contains some 

fragments of lignltized wood...... 0-2 

Unconformity(?). 

Twiggs clay member: 

·s. Laminated shaly fuller's earth, containing leaf impressions. The bedding dips west at a smaller angle 

than the unconformity below. 

Pinches out toward the east...... 0-6 

Lower Cretaceous: 

2. Silicified white sandy kaolin or flint 

clay; has been described as "argillaceous sandstone." The bedding 

dips 10° E. ; the unconformity 

above dips 15° W. in the head of 

the gully ........................ . 

1. Soft plastic white kaolin, · interbedded with white and yellow sand, 

with some kaolin conglomerate 

near the bottom of the ,exposure .. 

12 

12 

1 Berry, E. W., U. S. 'teo!. Survey Prof. Paper 84, pp. 130-131, 1914. 
DEPOSITS OF CLAIBORNE AND .JACKSON AGE IN GEORGIA. 65 

Grot,etown.-Fuller's earth exposed in the 

railroad cut at Grovetown station extends 4 

feet above track level and is overlain unconformably by red sand. The large cut south of 

the st·ation shows 20 feet of cross-bedded red 

and white sand, overlying the fuller's earth. 

The altitude of the station is 495 feet above 

sea level, and the highest exposure of fuller's 

earth is at 500 feet. 

Fuller's earth was formerly mined on the 

Fiske property, about a quarter of a mile ea~t 

of the station. When visited in 1916 the p1t 

was filled with water, but according to the sec-

. tion given by Veatch and Stephenson 1 it penetrated 10 to 12 feet of fuller's earth, whioh lay 

immediately above white olay of Lower Cretaceous age. The earth was not a commercial 

success for bleaching, probably because it contains a considerable amount of pyrite, which 

readily becomes oxidized to iron sulphate and 

sulphurous acid after drying. 

From this pit were obtained collections of 

fossil plants, which have been studied and described by Berry. 2 

A well at Usry Bros.' gin, near Grovetown 

station, penetrated 12 feet of fuller's e~rth that 

is very massive and thick bedded and IS cut by 

several systems of widely spaced joints. It is 

dark gray when fresh and wet but becomes 

almost white on drying and weathering. It 

contains flakes of mica, small crystals of pyrite, and fragments of carbonized wood and 

· sten1s. . 

Chapman lignite mine.-About 3 miles south 

of Grovetown a bed of lignite and lignitic clay 

occupies the horizon of the Twiggs clay. This 

material was formerly mined by W. C. Chapman for use as a fertilizer filler, but it was sufficiently carbonaceous to be used as fuel under 

the boiler at the grinding plant. 

Section in lignite pit 3 miles south of Grovetown. 

Barnwell formation: Feet. 

13. Gray or brownish incoherent sand, capping the hilL . . . . . . . . . . . . . . . . . . . . . 3-4 

12. Coarse red argillaceous sand, with a bed 

of fine gravel at the base......... . . . . 10 

Apparent unconformity. 

11. White, yellow, and red laminated plastic clay ... _ . . ................ . ..... 1-4 

10. Coarse angular yellow quartz sand; contains limonite fragments and in places 

fine gravel....... . . . . . . . . . . . . . . . . . . 15 

1 Op. cit., p. 269. 2 Berry, E. W., op. cit., pp. 129-163. 

Barnwell formation-Continued. Feet. 

9. Varicolored cross-bedded sand and fine 

gravel, with some layers of white 

plastic clay a few inches thick. . . . . . 35 

8. White to buff or pink plastic clay, filling depressions in the surface of the 

lignite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0-1 

Unconformity. 

Twiggs clay member: 

7. Black lignite. . . . . . . . . . . . . . . . . . . . . . . . . 2-4 

6. Gray plastic clay ............ -.... : . . . 1 

5. Black lignite . . ... -................. - . 1 

4. Gray clay, extremely plastic.......... 1 

3. Black lignite , containing large fragments of carbonized wood. . . . . . . . . . . 1 

2. Lj.ght-brownplastic lignitic clay....... 1. 5 

1. Dark-brown clayey lignite........... . . 1. 5 

75± 

JEFFERSON COUNTY. 

Nearly the whole of Jefferson County is underlain by the Barn~ell formation, and its 

outcrop covers all of the county except a part 

near the northern boundary, where several 

streams have cut their valleys down into the 

Lower Cretaceous beds, and the area south of 

Louisville, where the hills are capped by beds 

of Miocene (Alum Bluff) age or younger. 

The Twiggs clay member is thin but fairly 

persistent and appears in a line of exposures 

of fuller's earth across the northern part of the 

county. In general, the fuller's ear~h of this 

county contains less iron and is whiter than 

the deposits farther west. Some of it is soft 

and very light and porous, but farther east a 

larger proportion has become indurated into 

rather hard rock by the deposition of silica 

in the pores. Some of the silicified fuller's 

earth resembles the indurated Cretaceous kaolins found in the same area but n1ay be 

distinguished from them on analysis by its 

much higher ratio of silica to alumi.na. Southward from the northern border of the Barnwell 

formation the earth grades into calcareous clay, 

marl, and oyster-shell beds, which have few of 

the characteristics of a true full-er's earth. · 

The upper part of the Barnwell formation 

is made up of a considerable but unmeasured 

thickness of · red sand containing thin · beds of 

plastic clay, locally indurated layers of fossiliferous or barren sandstone and thin beds of 

fossiliferous flint residual from original lenses 

of impure limestone. · 

Louisville.-One of the best sections of the 

upper part of the Barnwell formation is ex-
66 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

posed in a gully on the east slope of Rocky 

Comfort Creek, about 300 yards above the 

wagon bridge three-quarters of a mile west of 

Louisville. 

Section three-quarters of a mile west of Louisville. 

Barnwell formation: Feet. 

8. Massive brilliant-red argillaceous sand..... 10+ 

7. Fine white silica or tripoli, probably a decomposed chert bed ..................... 1-2 

6. Indurated yellow sand...................... 6 

5. Bluish and yellow mottled clay, laminated 

but rather plastic, intermediate in properties between fuller's earth and common 

pipe clay..... . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

4. Coarse gray sand with a little clay, partly 

concealed....... . . . . . . . . . . . . . . . . . . . . . . . . . 14! 

3. Gray sand and yellow clay, locally indurated. 2 

2. Concealed intervaL....................... 15 

1. Blue calcareous fossiliferous argillaceous 

sand, weathering yellow; from creek (215 

feet above sea level)..... . . . . . . . . . . . . . . . 5 

57! 

As the red sand bed, No. 8, continues to tbe 

level of Louisville Court House (315 feet above 

sea level), the total thickness is 100 feet. 

A bed of Ostrea georgiana shells in a matrix of 

calcareous clay resembling fuller's earth is exposed at low water in the south bank of Ogeechee River,• 200 yards upstream from Cowart's 

Bridge, 2.6 miles south of Louisville. The 

bed is entirely similar to those at Danville, 

Twiggs County, and at Shell Bluff. Its 

altitude is a few feet below the base of the section on Rocky Comfort Creek. 

At Warren's Mill, on Big Creek 3 miles eastnortheast of Louisville, a bed of rock containing Ostrea georgiana was excavated for use in 

building a dam. There are no natural exposures of the oyster bed, but above water 

level in the creek (altitude 245 feet above sea 

level) is exposed 3 . feet of blue caJcareous 

fuller's earth, which dries and weathers white. 

This grades upward, by interbedding, into 

yellow argillaceous sand containing laminae of 

fuller's earth and fragments of oyster shells. 

. Old Town.-At Old Town Plantation, 8.4 

miles by road southeast of Louisville, a bed of 

rotten fossiliferous chert in the red sand is exposed on the slopes up to 20 feet above. the 

level of a small creek (altitude between 220 and 

250 feet). Collections of fossils made by S. W. 

McCallie, Earle Sloan, and T. W. Vaughan were 

identified by Vaughan, who supplied the following list of fossils for the Coastal Plain 

report: 1 

Mortonia sp. 

Caricella pyruloides Conrad. 

Turritella carinata Lea. 

Mesalia vetusta (Conrad). 

Calyptraea aperta (Solander). 

Glycymeris staminea (Conrad). 

Glycymeris idonea (Conrad). 

Glycymeris n. sp. 

Crassatellites protextus var. lepidus Dall . . 

Crassatellites n. sp. 

Venericardia alticostata Conrad. 

Cytherea perovata Conrad. 

Spisula praetenuis (Conrad). 

Corbula densata Conrad. 

Lunulites distans Lonsdale. 

More recent collectionsfurnished the species 

in the following list: 

Station 7428. Old Town road, east side of Boiling Spring 

Creek. J. E. Brantly, collector, 1915. 

Mortonella quinquefaria (Say)? 

Plejona petrosa (Conrad)? 

Turritella carinata Lea. 

Mesalia vetusta (Conrad). 

Glycymeris staminea (Conrad). 

Venus? sp. 

Cytherea perovata Conrad. 

Crassatellites protextus (Conrad) var. 

Protocardia sp. 

Diplodonta aff. D. ungulina (Conrad), very close to 

species in basal Jackson at Sims, Miss. 

Wrens.-Fuller's earth is exposed at anumber of localities in the vicinity of Wrens and 

has been cut by many wells in and around the 

village. The earth is almost white, nonplastic, and noncalcareous and shows various 

degrees of induration. A section is e;xposed 

on the north slove of Brushy Creek, on the 

Louisville road 1 mile south of Wrens. 

Section 1 mile south of Wrens. 

Barnwell formation: Feet. 

4. Yellow sand · with interlaminated clay, 

conformable with the underlying fuller's earth............................ 20 

Twiggs clay member: 

3. Slightly indurated fuller's earth, porous, 

laminated, greenish when wet but becoming pure white on drying. Contains laminae and beds of greenish sand 

as much as several feet thick.. . . . . . . . . . 20 

2. Light-greenish argillaceous sand, slightly 

indurated ............ ,................. 5 

1. Concealed interval from creek leveL . . . . . 5 

50 

t. Georgia Geol. Survey Bull. 26, p. 292, 1911. 
DEPOSITS OF CLAIBORNE AND JACKSON AGE IN GEORGIA. 67 

The section extends from 360 to 410 feet 

above sea level, and 410 feet is also the ~ltitude 

of Wrens station. 

Indurated fuller's earth unconformably overlies the Cretaceous at an altitude of 325 feet 

above sea level at Hatcher's Mill, on Reedy 

Creek 5.2 miles north of Wrens; and at Patterso'n's Bridge, on Brier ·creek 7.7 miles northeast of Wrens, is an exposure of sandy laminated 

fuller's earth, a part of which is indurated and 

resembles that at Hatcher's Mill. 

GLASCOCK COUNTY. 

The unconformity separating the Lower Cretaceous from the Barnwell formation is plainly 

shown on the Gibson-Mitchell road at Jumping 

Gully Creek, 2 miles west of Gibson. The 

section at this locality was given by Veatch 

and Stephenson 1 and need not be repeated 

here. All the strata above the CretaceousEocene unconformity, which lies at an altitude 

of 410 feet, should be referred to the Barnwell 

formation. 

An inter~sting section, which shows the 

variability of the basal · beds of the Barnwell, 

is exposed in the pits of the Harbison & Walker 

Refractories Co., east of milepost 48 on the 

Augusta Southern Railroad, 2 miles east of 

Gibson. The pits are in the eastern escarpment of Rocky Comfort Creek. 

Section in fire-clay mine 2 miles east of Gibson. 

Eocene: 

Section at Rocky' Comfort Creek 1.1 miles north of Gibson. 

Eocene: 

Barnwell formation: Feet. 

9. Massive red sand to top of hilL, ......... 45 

8. Interbedded red sand and red and gray 

plastic clay . . ............. : . . . . . . . . . 10 

7. Mottled argillaceous sand, without kaolin 

fragments ..... __ .............. : .. . .. 20 

6. Mottled arglllaceous sand, with small angular fragnients of indurated kaolin... 7 

5. Fine gravel, with angular fragnients of 

indurated kaolin ...... __ ..... _ . _ . . -.. 1 

4. Limonite-cemented sandstone ... __ ... _ _ . 1 

Unconformity. 

Lower Cretaceous: 

3. Yellow, white, and mottled kaolinic sand 5 

2. Concealed interval. __ . . . . . . . . . . . . . . . . . 50 

Pre-Cambrian(?): 

1. Granite ............................ _ . . . 20 

158.1 

. The altitude of this section is 355 to 515 

feet above sea level, and the Cretaceous beds 

occupy only the interval from 37 5 to 430 feet. 

The granite mass outcropping to 20 feet above 

the level of the creek is prohably a hill or monadnock in the pre-Qreta~eous surface, as no 

more igneous rock is seen for some miles farther 

north. 

Other localities in Glascock County, with the · 

fossils obtained at them, have been discussed 

on pages 46-4 7. 

. WASHINGTON COUNTY. 

The Barnwell formation is present throughout a large part of Washington County. The· Barnwell formation: Feet. b · · f ed Within the ormation most easily recog- 4. Yellowish sand with few pebbles...... 7 

3. Conglomerate of yellow sand and peb- nized by its lithology ·is the fuller's earth of the 

bles; where bed 2 is absent, this bed Twiggs clay member, which, although disconrests directly upon the Cretaceous .. __ 0-6 tinuous and variable in thickness, can be traced 

2. Gray to yellow indurated laminated clay by a line of outcrops from · Oconee across the 

or shale, with leaf impressions; at the county to Chalker. The beds underlying the 

base is a patch of impure lignite which 

grades upward into the gray plastic fuller's earth average about 50 feet in thickness 

clay; fills erosion hollows in the sur- and consist chiefly of calcareous clay and sand, 

face of the Cretaceous.............. 0-4 with locally indurated beds of quartzite conUnconformity (altitude 340 feet above sea level). taining a characteristic lower Jackson fauna. 

Lower Cretaceous: Above the Twiggs clay member is red sand, 1. Gray fire clay and indurated kaolin, not 

very hard but extremely brittle. .__ _ l0-l5 with lenses of impure limestone containing 

On 'the Gibson-Warrenton road 1.4 miles Mortonella quinquefaria (Say), which probably 

represent the chert zones of Jefferson and 

north of Gibson is exposed a section of the Burke counties. The exposures of limestone 

entire Cretaceous and lower part of the Eocene. extend from Wring Jaw Landing, on Oconee 

There are no fossil.-bearing beds, but the sec- River a short distance south of the Washington 

tion is typical of deposition near the shore line. · County line, to Sunhill, passing between San:. 

1 Op. cit., p. 273. dersville and Tennille, and outliers of the same 
68 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918: 

rock are 'thought to occur 2! miles south of 

Warthen, but <;letails are not available. 

Bu.ff'alo Oreek.-The Barnwell formation is 

well exposed in the steep · escarpment east of 

Buffalo Creek, and sections have been measured 

along the roads east of Sheppard's Bridge, 

which is 3 miles north of the mouth of the creek 

and east of Turl_lpike Bridge, 5 miles farther 

north. 

Section along road east of Sheppard's Bridge, 1! miles north 

of Oconee. 

Eocene: 

Barnwell formation: Feet. 

9. Red sand with plastic clay, laminated 

toward base ....................... 70 

Twiggs clay member: 

8. Plastic laminated yellowish-green clay 12 

7. Light-yellow nonplastic porous fuller's 

earth....................... . ..... 5 

6. Gray plastic clay, more or less sandy. 14 

5. Massive gray argillaceous sand, with 

casts of fossils, Pecten perplanus, 

Panope, GlyGymPris....... . ....... 6~ 

4. Interbedded sand and fuller's earth.. 7~ 

3. Gray, v6ry plastic sandy clay, becoming more sandy. toward the top. 

The upper portion contaiiL'3 Flabell1lm and other poorly preserved fossils .............................. 27 

2. Gray sand, mottled with red; at base 

contains quartz pebbles as much as 

H inches long; c1ay laminae near 

the top.......................... 6 

Lower Cretaceous: 

1. Cross-bedded kaolinic sand from level 

of Buffalo Creek. This may include 

the basal beds of the Eocene, as the 

contact has not been exactly determined ........................... 70 

218 

The altitude of the base of bed 2 of the preceding section is about 285 feet a'hove sea level. 

Section along road east of Turnpike Bridge. 

Eocene: · 

Barnwell formation: Feet. · 

9. Red sand. .......................... 35 

Twiggs clay member: 

8. Greenish plastic laminated sandy clay 10 

7. Fuller's earth. The exposures are not 

quite continuous, and there may be 

interbedded sandy strata in the 

covered intervals. All the earth in 

sight, however, appears to be of sufficient purity for use as a bleaching 

earth. It is light greenish yellow, 

fine grained, nonplastic, noncalcareous, and somewhat iron stained on 

account of its proximity to the surface but contains very little sand... 40 

Eocene-Continued. 

Barnwell for-mation-,--Continued. - Feet. 

Twiggs clay member-Continued. 

·6. Covered interval. Beds probably of 

same_ character as the next underlying stratum. A spring emerges 

near the top of the intervaL . . . . . . . 20 

5. Dark-gray-sandy clay ..... :. . . . . . . . . . 5 

4. Greenish, slightly plastic clay, resembling fuller's earth in appearance, . 

containing considernble sand and 

a few foasils . . . . . . . . . . . . . . . . . . . . . . 25 

3. Sandy and calcareous clay; containing 

Flabellum.......... . . . . . . . . . . . . . . . 3 

2. Gray sandy clay at base, grading upward into blue or greenish, very 

plastic gumbo or pipe clay. . . . . . . . . 12 

Unconformity (altitude 300 feet above sea level). 

J.,ower Cretaceous: . 

1. Light-colored sand containing lenses 

of white kaolin, from level of · Buffalo Creek ..................... : . . 70 

220 

Sandersville.-Near the Little Keg . Creek 

bridge, 7.2 miles by road northwest of Sandersville and 8 miles in an air line ·northeast of 

Turnpike Bridge (see section and discussion, 

p. 48), the fuller's-earth bed is not present, but 

it comes in again farther south and is exposed 

where the same road crosses Rocky Branch, 

3.2 miles by road northwest. of Sandersville. 

Section along public road wuth of Rocky Branch, 8.2 miles 

northwest of Sandersville. 

·Barnwell formation: Feet. 

6. Massive red sand to top of hilL........... 90 

5. Gray and yellow argillaceous sand........ 12 

Twiggs clay member: 

4. Greenish fuller's earth, containing a few 

laminae of sand ....... ~ . . . . . . . . . . . . . . . 10 

3; Red sand with laminae and thin beds of 

greenish fuller's earth ........ ·.......... 10 

2. Gray and greenish clay, becoming sandy 

and fossiliferous toward the top .. ·...... 7 

1. Concealed interval from level of Rocky 

Branch............................... 5 

134 

As the base of this section is at an altitude 

of 330 feet, it can not be far above the top of 

the Cretaceous. 

Limestone referred to the upper part of the 

Barnwell formation is exposed at the spring 

and lime sink at the head of Limestone Creek, 

1 mile south of the courthouse at' Sandersville. 

The topographic relations of the exposures are 

well shown in the sketch map by Brantly.1 

The section is as follows: 

1 Brantly, J. E., Limestones and marls of the Coastal Plain of Georgia. 

Georgia Geol. Survey Bull. 21, p. 59, 1916. 
DEPOSITS OF CLAIBOR.NE AND JACKSON AGE IN GEOR.GIA. 69 

Section 1 mile south ~~ Sand~~cille. j th f , 1· 'J ~ presence o out 1ers of this bed several 

Barnwell formation: Feet. miles north of the exposures described. 

6. Red sand to top of hilL ... -.-............... 10± lVarthen:~A good exposure of the Twiggs 

5. Coarse gray sandstone, irregul~ly indurated clay member of' the Barnwell formation is 

and terminating laterally in red sand._____ 6 found on the property of A. J. Irwin, 3 miles 

4. Gray sand, oxidized red and yellow, exposed' 

along road. __________________ . ________ . _ _ 15 south of W ~rthen and 6 miles north of Sanders3. Light-gray chalky limestone; contains Mor- ville, at the head of a branch of Little Keg 

tonella quinquejaria (Say) in abundance Creek. 

and casts of other fossils; Ostrea georgiana 

is reported here. 1 Exposed in sink. . . . . _ . . 12 

2. Gray, very sandy l~mestone with obscure 

fossils __ . ____ _ . _ . __ . _______ . __________ . _ _ 5 ± 

1. Bright-blue incoherent sand, apparently· 

grading laterally into gray sandy limestone. 

Exposed in stream below sink .. _ ~ ______ . _ _ 2 

. The altitude of the base of the exposure is 

400 feet, which must be ,approximately 100 

feet above the top of the Cretaceous and stratigraphically higher than the calcareous fuller's 

earth and limestone beds found in a well near 

Limestone Church, 3 miles down the creek. 

The yellowish and mottled sands that cap the 

hills within a mile sou~h of this· exposure probably belong to the Alum· Bluff formation . ' 

Section on Irwin property, 3 miles south of Warthen. 

Barnwell formation: , Feet. 

5. Massive red sand. This bed overlies the 

clay with a sharp contact, showing no 

sign of gradation, which may represent 

a local unconformity. _ .............. _ _ 40 

Twiggs clay member: · 

4. Greenish plastic clay and indurated 

sandy clay ........ ---- .......... _. __ . . : _ 2 

3. Good fuller's earth, brovm.ish gray when 

dry, laminated, brittle, and free from 

grit.-----------------------"-- ------ -- 8 

2. Plastic greenish clay, with a tendency to 

crumble on drying ____ ._._. _____ .... __ 15. 

1. Greenish sandy, non plastic clay resembling fuller's earth, containing thin 

beds of sand and plastic clay ......... __ . 20 

whiCh overlaps the beds of Vicksburg age. · 

Sunhi,ll.-Limestone· of the same horizon as 

85 

that exposed at Sandersville was formerly This section extends f~om 365 to 450 feet 

used in the manufacture of lime at Sunhill. above sea level, with the top of the clay memThe old kiln and quarry are on the south slope ber at 410 feet. The normal dip of the beds 

of Williamson's Swamp Creek, an eighth.of a would carry the clay well below the limestone 

mile southeast of the station. Brantly z gives exposures at Sandersville and Sunhill. 

the .following section: , j On the J?roperty of John an~ George Powell, 

Section in old quarry at Sunhill. 

Feet. 

5. Red argillaceous sand ......... __________ .. _______ 10 

t Medium-grained white sand grading into yellow 

i about 1 mile north of the locahty on the Irwin 

property just described, are outcrops of a bed 

of white to dark-brown cherty sandstone containing small masses and veinlets of iridescent 

sand·------------------------ ____ .. __ __ .. __ . . . 

3. White calcareous clay. _____ ._ .. _____ __ . ________ _ 

2. · Arenaceous limestone or calcareous sandstone .. __ . 

1. Hard white compact, partly crystalline limestone. 

5 opal, some of which are said to be large enough 

2 to cut as gems. Much fragmental material 

: from this bed is scattered in the· vicinity of the 

outcrops. The chert contains silicified frag29 ments of echinoids, but determinable fossils 

As the altitude of the base of this section is 

355 feet above sea level and as the normal dip 

of the beds is about 10 feet to the mile toward 

the southeast, the limestone must lie at about 

the same horizon as that at Sandersville. 

Specimens of Mortonella ·quinquejaria (Say) 

in a matrix of limestone like that near Sandersville and Sunhill, collected by S. W. McCallie 

on the T. W. Smith farm, 2! miles south of 

Warthen (U. S. G. S~ station 3953), indicate 

I Veatch, Otto, and Stephenson, L. W ., Georgia Geol. Survey Bull. 26, 

p. 253, 1911. 

sOp. cit., p. 61. 

are rare. 

The stratigraphic position of this chert bed 

is very near the base of the Barnwell. Beds of 

chert and sandstone at the base of the Barnwell 

are more extensively developed and more fossiliferous farther northeast, in the vicinity of 

Chalker and Gibson~ 

Ohalker.-Near milepost 65 on the Augusta 

Southern Railroad, 1! miles southwest of 

Chalker, a lens of sandy kaolin of Lower Cretaceous age (used in the manufacture of common pottery) is overlain unconformably by 6 

feet of bedded yellow to white clayey sand of 
70 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Eocene age. A quarter of a mile southwest of 

the pottery pit about 10 feet of indurated 

fuller's earth is exposed above the railroad level, 

overlain by a thin bed of quartzite, and below the railroad level and just above the Cretaceous is a bed of hard fossiliferous sandstone. 

The following species were obtained at this 

-locality: 

Station 7708. Base of Barnwell formation , Augusta Southern Railroad , 1~ miles southwest of Chalker, Washington 

County, Ga., Cooke and Shearer, collectors, 1916. 

Mesalia vetusta Conrad. 

TUrritella carinata Lea. 

Centhium sp. 

Glycymeris staminea (Conrad). 

Mytilus texanus (Gabb ). 

Corbula alabamiensis Lea. 

Meretrix sp. 

V enericardia sp. 

To these 'should be added Flabellum cuneiforme Lonsdale, Barl>atia cuculloides (Conrad), 

and Ostrea georgiana Conrad~ (identified· by T. 

W. Vaughan?) ~ which were collected by S. W. 

McCallie at the same locality (station 3945). 

One mile south of Chalker, where the road 

to Sandersville ascends from the Ogeechee 

Valley to the upland plain, a section is exposed 

which carries no fossiliferous beds but shows 

well the character of the Barnwell formation. 

,_ Se(ftion along Sandersville road 1 mile south of Chalker. 

Eocene: 

Barnwell formation: Feet. 

. 10. Massive red and mottled sand to top 

of hilL ...... •....... ·. . . . . . . . . . . 30 

9. Red sand with laminae of white and 

bright-purple clay. This coloring is characteristic of the Alum 

Bluff formation in the southern 

pu,rt of the State, but it is unlikely that that formation extends 

so far north. . . . . . . . . . . . . . . . . . . . . . 17 

8. Yellow and mottled sand............ 16 

Twiggs clay member: 

The Cretaceous surf ace ·in this area, as well 

as in the counties farther east, is much more 

irregular than to the west, showing a drop of 

no less than 50 feet between this exposure (altitude about 385 feet) and the vicinity of the 

sandstone exposures not more than a mile 

away. 

WILKINSON COUNTY. 

The upland areas of Wilkinson County are 

underlain by beds of Jackson age, but Oconee 

River and Commissioners and Big Sandy 

creeks have cut their valleys down into the 

Lower Cretaceous strata. The Barnwell strata 

cover the southern part of the county and form 

a narrow lobe along the ridge between ~ig 

Sandy and Commissioners creeks and an elongated erosional outlier between Commissioners 

Creek and Oconee River. Both of the latter 

areas extend beyond the northern boundary of 

the county. · Chert of Vicksburg age is found 

along the southern county line, and it is possible, as in Twiggs County, that a part of the red 

sand farther north belongs to that formation. 

· A gradual change in the character of the deposits of Jackson age from west to east is noticeable in the area between Ocmulgee and Oconee 

rivers. The Tivola tongue of the Ocala limestone is nearly 50 feet thick along the Ocmulgee, 

in Twiggs and Houston counties, but it pinches 

out before reaching the Oconee. .In Wilkinson 

County it is thin and very impure and is absent 

at many localities. The largest exposure is on 

the property of th~ General Bauxite Corporation near Toomsboro, but the bed there carries only about 50 per cent of calcium carbonate, 

the remainder being sand and clay. The limestone that is expose~ on Oconee River at Wring 

Jaw Landing, Johnson County, 2 is correlated 

not with·the bryozoan-bearing limestone of the 

southwestern part of the State but with the 

7. Greenish laminated fuller's earth, 

stained and somewhat plastic on 

account of weathering ......... . .. . 

6. Coarse yellow sand ................ . 

limestone beds at a higher Jackson horizon 

11 which are . exposed near Sandersville. (See 

11 pp. 68-69.) 

5. Greenish laminated fuller's earth, 

· free from sand ................... . 

4. Concealed intervaL ................ . 

3. Fuller's earth containing a little sand. 

2. Sand with laminae of fuller's earth .. 

Lower Cretaceous: 

In Wilkinson County the Twiggs clay mem1 her is less persistent and less pure than in 

10 Twiggs County, and the material is generally ! too sandy or calcareous to serve as a commer1. White sand with kaolin lenses; to 

level of Chalker station............ 55 

cial fuller's earth. Locally both limestone and 

fuller's earth are absent, and the Barnwell formation consists entirely of red sand with a few 

159 thin beds of plastic clay or gumbo. · 

1 Georgia Geol. Survey Bull. 26, p. 276, 1911. 2 Veatch, Otto, and Stephenson, L. W ., op. cit., p. 305. 
G01'don.-A section typical ofthe be~ in the Toomsboro.-In he immediate vicinity of 

D»POSITS OF CLAIBORNE AND JACKSON AGE IN ~EORGIA. 71 

northern part of the county is exposed ~n a pit Toomsboro no lim stone nor fuller's earth is 

of the Savannah Kaolin Co., 1 mile sl uth of exposed and the : arnwell seems to consist 

Gordon. . entirely of red san4, but the missing beds cr~p 

·section in pit o.if Saranr..ah Ki . aolin Co. out on the property of the General Bauxite 

Eocene: . Feet Corporation, 3 mil · s west of the station. No 

Barnwell formation (upper part): . . . 5. Red and mottled argillaceous and comple~e sectiOn \ exposed.. The. following . 

to the top of the hilL . . . . . . . . . . . . . 60 sectiOn Is made up from an_erOid readings taken 

Twiggs clay member: at widely separatec outcrops: 

4. Greenish-yellow fuller's earth, con-

. taining chalk nodules and a few Section on property of the General Bauxite Corporation, 

fossils ............. ·······.· · · · · · · 10 3 miles est of Toomsboro. 

Ocala limestone (Tivola tongue): 

3. Sandy limestone, with Pecten perplanus and abundant bryozoa..... 4 

Barnwell formation (basal part): 

2. Argillaceous glauconitic sand · fi ling 

erosion depressions in the C etaceous surface ....................... 0-2 

Unconformity. 

Lower Cretaceous: 

1. Massive white kaolin. . .. . . . . . . . . . . . . 30 

106 

Bed 3 of this section represents the tip of 

the Tivola tongue of the Ocala limestofe. 

Big Sandy Valley.-In the exposure · along 

the Valley of Big S-andy Creek the Tivola tongue 

of limestone is generally absent or is represented by local beds of fossiliferous ch rt, but 

the fu1ler' s earth bed is well develo ed. A 

typical section is exposed along the pub · c road 

on the southwest side of Big Sandy Creek near 

Sa:ud Bed Bridge, 3 miles south of Irwifton. 

Section near Sand Bed Bridge, on southwest side ojl ig Sandy 

Creek. 

Eocene: 

Barnwell formation: Feet. 

6. Red, yellow, and mottled argilla~eous 

sand, containing some thin be s of 

plastic clay........................ 40 

Twiggs clay member: 

5. Thin bed of sticky yellowish clay not 

well exposed...................... 5? 

4. Fuller's earth, containing a few partings of yellow sand not over 1 inch 

thick, but the greater part of t~e interval is thick-bedded light-co ored 

3. ve:~t:i~tl~ .bi~ish ~i~~~ -~~~~~~i -f~~t 25 

exposed, but the top and bottof of 

the bed are concealed. . . . . . . . . . . . . 5? 

2. At bottom red sand with lamin e of 

clay resemJ:>ling fuller's e rth; 

above, mottled red and bl ish 

clayey sand....................... 25 

Unconformity. 

Lower Crataceous: 

1. Massive white kaolin................ 15 

115 

Eocene: 

Barnwell formatio~: 

5. Red sa ds capping hills. Altitude 

in feet. 

300 

Ocala limestone (T: vola tongue): 

4. Calcare< us fuller's. earth ........ . Twiggs clay m~mber: 

3. Hard a d soft yellow impure 

limes one (50 per cent CaCOJ, 

conta ning Pecten perplanus, 

Periarchus pileus-sinensis, ·and 

Bryo oa of the Rich Hill facies 

of th Jackson fauna .......... 270-290 

Unconformity .................. ~ ......... ~ . . . 250 

Lower Cretaceous: 

2. BauxitE lenses. 

1. Kaolin : nd kaollnic sands. 

BALl WIN COUNTY. 

So far as known only one lobe of the Barnwell formation enters Baldwin County. The 

Barnwell material forms the overburden at 

the fire-clay pits of the Stevens ·Bros. Co., 

at Stevens Potter}; and in one of these pits 

the section given l:J.elow was measured. 

Section in cl y pit, Stevens Pottery. 

Eocene: 

Barnwell formatioDJ (Twiggs clay member): Foot. 

5. Soil, consist ng of weathered fuller's earth 

mixed wi1th red sand ...... _. . . . . . . . . . . 3 

4. Fuller's ea: th, sandy, iron-stained, of 

higher s cific gravity than' commer- . 

dally val able earth of Twiggs County 

but very imilar to the latter in appearance and omposition; contains casts of 

fossils. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

3. Blue argill ceous marl; Bryozoa very 

abundant in lower part; Mollusca more 

abundant toward top.................. 10 

2. Light-green lauconitic clayey sand filling 

minor irr gularities in the Cretaceous 

surface; c ntains a few Bryozoa. . ..... . . 0-2 

Lower Cretaceous: 

. L Massive kao ·n, locally sandy or bauxitic, 

used as fi clay........................ 20 

47 
72 - SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Statjon 7755. Bed 3 of section at Stevens Pottery, Central 

of Georgia Railway, Baldwin County, Ga. C. Wythe 

Cooke, collector, 1916.· 

Bryozoa (Rich Hill facies of Jackson fauna). 

Turritella cf. T. arenicola var. branneri Harris. 

Cal yptraea sp. 

N ucula ovula Lea. 

Yoldia sp. 

Leda cf. L. coelata Conrad. 

Leda albirupina Harris? 

Panope oblongata (Conrad)? 

Pecten perplanus Morton? 

Pseudamusium sp. 

Corbula oniscus var. (probably) wailesiana Dall. 

Phacoides (Miltha) claibornensis Qonrad. 

Tellina sp. 

Tagelus?· sp. 

Cytherea discoidalis Conrad? (also at Roberts). 

V enericardia planicosta (Lamarck). 

Venericardia sp. · 

JONES COUNTY. 

Several small isolated areas of beds of Jackson age extend into the southern part of Jones 

County, locally overlapping the Lower· Cretaceous deposits and resting upon the crystalline 

basement rocks. 

Interesting exposures of fossiliferous beds 

, occur in the cuts of the Georgia Railroad, 

near Roberts, 9.4 miles by rail northeast of 

Macon. The best section is shown in the cut 

1 mile northeast of the station, near the overhead crossing of the Central of Georgia Railway. 

Sectwn in cut 1 mile northeast of Roberts.1 

Eocene: 

Barnwell formation : Feet. 

6. Loose red sand, containing a few 

scattered quartz pebbles; no fossils 

observed. __ •...................... 10 

. Twiggs clay member: 

5. Greenish and dtab laminated sandy 

clay (fuller's earth), porous and of 

low, specific gravity_.............. 12 

4. Laminated sandy clay containing 

white chalk nodules and casts of 

fossils. The upper 2 feet of the bed 

is very fossiliferous. This bed L'3 a 

typical calcareous fuller's earth..... 8 

3. Bluish fossiliferous mud or marL...... 8 

Crystalline basement: 

2. Concealed a few feet.................. ? 

1. Crystalline igneous rock. 

The igneous rock does not appear in this 

cut but crops out in the next cut, a quarter of a 

mile farther northeast, where it is. overlain by 

red sand. The highest altitude reached by the 

crystalline rock in this cut is 590 feet; the 

base of bed 3 in the section is 595 feet above 

sea level. 

1 Adapted from Veatch, Otto, and Stephenson, L. W ., op. cit., p. 280. 

The amount of overlap of the Barnwell beds 

on the cry~talline rock at this point is not 

great, for in a cut less than a mile south of 

Roberts the red sand of Jackson age unconformably overlies gray micaceous kaolinic sand 

of the Cretaceous. 

Bed 3 closely resembles the corresponding 

stratum (No. 3) in the section at Stevens Pottery, and the sections are similar in other respects. 

The exposures near Roberts were first studied by Harris,Z who referred the strata to 

the upper Wilcox ("Lignitic"). Preliminary 

study of collections of fossils made by McCallie, 

Sloan, and Vaughan led Vaughan 3 to the conclusion that the beds are of lower Claiborne 

age. It appears, however, that the determinations of the most critical species were based 

on very imperfect material, and the correctness of some of them is open to question. The 

list of species as here revised contains a number of species in common with the lower tTackson fauna of Arkansas and bears a close, resemblance to that of the species occurring in 

the lower part of the Barnwell formation near 

Gibson. This opinion of the age is in accordance with the lithologic and structural evidence, which shows that these beds are of the 

same a:ge as the fuller's earth and bryozoanbearing limestone of Twiggs County. Therevised list of species follows: 

Fossils from cut on Geor_gia Railroad 1 mile east of Roberts, 

Jones County. . . 

[Identified by T. W. Vaughan; list.revised by C. W. C-wke.] 

Collected by-

.McCallie. Sloan and 

Vaughan. 

Endopachys maclurii (Lea) .................. _. X 

Oylichna sp ........ ~............... X 

Plejona petrosa (Conrad) ... _._...... X X 

Clavelithes sp. . . . . . . . . . . . . . . . . . . . . . X .. _ ... . . . Mamalina sp . . . . . . . . . . . . . . . . . . . . . . . . ....... . 

Pseudoliva vetusta (Conr~.d) ................. . 

X 

X 

X 

Levifusus branneri Harris? ........ _, .. 

1 

. ..... · .. . 

Turritella a pita De Greg............. X ........ _ Turritella sp ........................ _ ...... X . Turritella carinata Lea?............. X ........ . Turritella arenicola Conrad ................. _. Natica sp ........................ _... X 

Calyptraea aperta (Solander): ...... ~ X 

Adeorbis sp. . . . . . . . . . . . . . . . . . . . . . . . . X 

N ucula ovula Lea.... . . . . . . . . . . . . . . . X 

Yoldia aff. Y. psammotaeaDall....... X 

Leda albirupina Harris.... . . . . . . . . . . X 

J,eda sp .............................. ~--- ... . Trigonarca sp............. . . . . . . . . . . . . X 

X 

X 

X 

X 

X 

X 

2 Harris, G. D., Eoceneoutcropsincentral Georgia: Bull. Am. Paleon• 

tology, vol. 4, p. 4, 1902. 

s ililorgia Geol. Survey Bull. 26, p. 282, 1911. 
DEPOSITS OF CLAIBOE NE AND JACKSON . AGE IN GEORGIA. 73 

Fossils from cut on Georgia. Railroad 1 mile east of Roberts, extends less than an inch from the surface, 

Jones County-Continued. · whereas in the northern part of the county the 

Collected byM Calli S oan and c e. V :~.ughan. 

Glvcymeris sp ............................... . Glycymeris trigonella (Conrad)? .. . .. ~ X Ostr~a a;labamiensis Lea. . . . . . . . . . . . . . .... . .. . Ptena hmula (Conrad) ....................... . Pecten n. sp .. : .............. ... ............ . Pecten (Pseudamusium) scintillatus 

Conrad. . . . . . . . . . . . . . . . . . . . . . . . . . . . X 

X 

X 

X 

X 

X 

Modiolus alabamiensis Aldrich. . . . . . . X ........ . Periploma sp ........ ... ........... .. ........ . Venericardia planicosta (Lamard~)-.. X . · Protocardia, probably P. nicolleti 

(Conrad) ... ......................... .... .. . Phacoides (Miltha) claibornensis 

(Conrad).......................... X 

Cytherea sp . . . . . . . . . . . . . . . . . . . . . . . . . . . ....... . Cytherea discoidalis Conrad? ........ 1 

• ••• ••••• 

Psammobia sp.. . . . . . . . . . . . . . . . . . . . . X 

Spisula parilis (Conrad) or S. funerata (Conrad) ............................. . Corbula oniscus Conrad............... X 

Corbula alabamiensis Lea .... -------- .

1 

X I 

TWIGGS COUNTY. 

X 

X 

X 

X 

X 

X 

X 

X 

X 

Vicinity of Pikes Peak.-The Twiggr.; clay 

member of the Barnwell attains its greatest 

thickness in Twiggs County, where, at Pikes 

Peak, it is mined for use as fuller's earth. The 

member changes considerably In character 

from north to south within the county.t , The 

best exposures in the northern part are n the 

property of the General Reduction Co. near 

Pikes Peak, where there are two well-~:fined beds of fuller's earth in an interval of abo t 100 

feet. The lower bed is about 45 feet thi k, the 

upper more than 20 feet, and the two ar!separated by a bed of greenish-yellow fossili erous 

sand which reaches a thickness of 30 feet. The 

earth in this vicinity is not calcareous, xcept 

near the. base, where it grades into lime~stone. Where leached and oxidized by surface water 

it has a pale-yellow to cream color and is extremely light and porous; but below th zone 

of oxidation it is usually dark gray and co tains 

organic matter and pyrite. Farther . outh, 

in the neighborhood of Danville and W e~tlake, 

for instance, the fuller's-earth bed befomes 

thinner as the underlying limestone tlckens 

and the clay becomes more and more calc eous. 

The calcareous clay is blue or gray wh n unoxidized, but becomes cream-colored or rellow 

at the sur.face. As it is much less pervio~ than 

the noncalcareous variety farther nort , the 

zone of oxidation in many parts of its o tcrop 

material is oxidized to depths of many feet. 

Section in fuller 's-earth mine of the General Reduction Co. 

half a mile northwest of Pikes Peak. 

Barnwell formation (?): Feet. 

_8. Massive dark-red sand.................. 17 

7. Fine quartz gravel, indistinctly bedded. 10 

6. Varicolored sands with thin layers and 

fragments of sticky plastic "gumbo" 

clay. Some layers of the sand are slightly indurated. . . . . . . . . . . . . . . . . . . . . . . . . 8 

Unconformity (?). 

Twiggs clay member: 

5. Light-colored fuller's earth. The lower 

portion is thin bedded, with fine sandy 

partings stained by oxides of iron and 

manganese. Toward the top the earth 

becomes more massive, and the beds 

are several feet thick between partings. 

The whole mass of fuller's earth is cut 

by joints in various directions, and iron 

and manganese stains are found along 

the joint planes. Some of the joints 

and partings are slickensided, showing 

that slight movements, probably caused 

by shrinkage, have occurred. This bed, 

which is uniform in texture and" composition and is very light and porous, 

eonstitutes the commercially valuable 

fuller's earth . . . . . . . . . . . . . . . . . . . . . . . . . 17 

4. Dark-colored fuller's earth, almost black 

when wet but becoming light gray on 

drying. The dark color is probably due 

to organic matter. The clay contains 

visible crystals of pyrite and gives off 

a strong odor of sulphur dioxide when 

dried at 100° C. It also contains scattered concretions of hard siliceous material. The black. layer thins to the north 

and west-that is, the slope of its upper 

surface follows the slope of the hill. The 

line of contact with the light-colored 

earth is sharp and even, but there is no 

visible change in texture, and the contact was observed to cut obliquely 

across the sand partings (bedding 

planes). It is ~vident that the light 

earth has been derived from the dark 

variety by leaching and oxidation of 

pyrite and carbonaceous matter...... 5 

3. Yellow-drab fuller's earth. The lower 

part of the bed is mottled and banded 

with grains and layers of dark-colored 

oxides of iron and manganese. . . . . . . . . 1 

2. Greenish-yellow sand containing some 

poorly preserved fossils. This bed is 

shown in borings in the floor of the mine 

and in wells near the mill. . . . . . . . . . . . 50 

1. Light-yellow fuller's earth, penetrated in 

wells near the mill .................. " . ? 

108 
74 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

The irregularity of the upper surface of the 

filller's-earth bed indicates an unconformity 

between beds 5 and 6, and an unconformity at 

the same horizon is seen between the red sand 

and the fuller's earth in the railroad cut at 

Pikes Peak station. In the absence of paleontologic evidence it can not be certainly stated 

whether this unconformity is within the Barnwell or whether it separates the Barnwell formation from the Vicksburg formation. 

On the property of J. D. Crump, which 

adjoins that of the General Reduction Co. on 

the northwest, and on the Lowe Wall property, 

1 mile farther south, 12 feet of limestone containing Bryozoa (Rich Hill facies of Jackson 

fauna), Periarchus pileus-sinensis, and P ecten 

perplanus occurs at an altitude a little more 

than 100 feet lower than the top of the fuller's 

earth in the section just given (which is 585 

feet above sea level). The limestone is under-

. lain by t enacious yellow sand. 

Gallemore.-A fossiliferous marl, consisting of 

fine quartz sand in a matrix of clay and calcium 

carbonate, is exposed in the bed of Turkey 

Creek (altitude, 380 feet above sea level) at 

Gallemore, or Willis, 4 miles northeast of Danville. That this marl is a shoal-water deposit 

of Jackson age is shown by the species in the 

following list: 

Station 7699. Boulders below mill at Gallemore, Twiggs 

County, Ga. C. Wythe Cooke, collector, 1916. 

Plejona petrosa (Conrad). 

Mesalia vetusta ·(Conrad). 

Nucula sp. 

Leda coelata (Conrad)? 

Glycymeris staminea (Conrad)? 

Corbula oniscus Conrad. 

Spisula parilis Conrad? 

Panope sp. 

Meretrix sp. 

Phacoides (Miltha) claibornensis (Conrad). 

Phacoides (Miltha) pandatus (Conrad)? 

Phacoides (:Jlere) alveatus (Conrad). 

Venericardia planico.sta (Lamarck). 

All theSB species are represented by casts and 

molds. The following additional species, identified by T. W. Vaughan, were cited from this 

loc~ity by Veatch and Stephenson:1 Oalyptraea aperta (Solander), Turritella carinata Lea, 

and Diplodonta ungulina (Conr~d) ~ 

Section along public road east from Gallemore. 

Oligocen~ (?): Vic~burg formation (?): Feet. 

· 7. Red argillaceous sand ... ·. . . . . . . . . . . . . . . . . . . . 60 

6. Basal conglomerate of red sand containing 

limestone and quartzite pebbles........... 1 

1 Op. cit., p. 256. 

Unconformity (?). 

Eocene: Barnwell formation: 

5. Red sand............. . ........ . ............ 10 

4. Plastic "gumbo" clay.............. . ......... 2 

3. Red sand................................... 10 

2. Concealed interval from creek to railroad level 15 

'1. Marl exposures in creek bed (station 7699). . . . ? 

98 

The unconformity between beds 5 and 6 

may be the same as that seen at Pikes Peak. 

Turkey Oreek.-Beside the tracks of the 

Macon, Dublin & Savannah Railroad just 

south of. Turkey Creek, 1 t miles northwest of 

Danville, hackly yellow fuller's earth, somewhat calciDreous and containing several thin 

ledges of hard argillaceous limestone near the 

top, rises 10 or 15 feet above the swamplevel. 

At the top (altitude about 380 feet) is a 

stratum of sandy calcareous clay loaded with 

shells of Ostrea georgiana associated with impressions of other mollusks, including a large 

Mytilus?. 

Sections near Dry Branch have been described on pages 42-44 and need not be repeated 

here. 

BIBB COUNTY. 

An area underlain by t.he Barnwell formation 

extends into the southern part of Bibb County 

near•Dry Branch and includes the localitie~ at 

Browns Mountain and Bond's store which 

have already been described (pp. 47-48). 

About 1! miles south of Bond's store, on the 

John Tharpe estate near the boundary between 

Twiggs and Bibb counties, the fuller's-earth 

beds become very prominent but the bryozoanbearing limestone and sandstone are absent. 

The section is well exposed in gullies above and 

·below the level of the Macon-Marion road. 

Section on the John Tharpe estate, ],[aeon-Marion road 

10 miles southeast of Macon. 

Eocene: 

Barnwell formation: Feet. 

4. Red sand, probably extending to top 

of hill, 75· feet in all. Thickness seen 55 

Twiggs clay member: 

3. Gray . hackly fuller's earth, more or 

less sandy throughout but especially 

so at top and bottom. Crassatellites 

and fossil plants (station 7694) found 

20. feet below top.................. 80 

2. Yellow sand to leyel of road........ 20 

:Unconformity. 

;Lower Cretaceous: 

1. White plastic kaolin and kaolinic sand ? 

155 
DEPOSITS OF CLAIBOR. E AND J ACI SON AGE IN GEORGIA. 75 

Prof. E. W. Berry has kindly furnishe the 

following annotated list of plants collect · d by 

the writers at this locality: 

Station 7694. Tharpe estate, 10 miles southeast of aeon. 

Acrostichum georgianum Berry (common; ew to 

locality). 

Dodonaea viscosoides Berry (common). 

Ficus clalbornensis Berry (common). 

Pteris inquirenda Berry (new to locality; lso at 

Newton, Miss.). 

Pisonia claibornensis Berry. 

Rhizophora eocenica Berry. 

Myrica nigricans Lesquereux (new to localit ; also 

Green River formation of Wyoming. Refe red by 

me to Cupanites). 

Potamogeton sp. (new). 

Carpolithus najasoides Berry, n. sp. (seed) 

The following additional species wer collected by Prof. Berry at the same localit ' 1 

Arundo pseudogoepperti Berry. 

Conocarpus eocenica Berry? 

Malapoenna sp. 

Mimosites georgiana Berry. 

Sphaerites claibornensis Berry. 

South and west of Macon there are s veral 

isola ted exposures of red sand with thin beds 

of plastic clay unconformably overlyin the 

light-colored sands and clays of the Upp and 

Lower Cretaceous and resembling the Ba nwell 

deposits of northern Houston County. 

BLECKLEY COUNTY. 

As the outcrops of the Barnwell be s in 

Bibb County are typical of near-shore d position, those of the northern part of Bl ckley 

County are typical of the deeper-water de osits 

now found near the southern limit of ex osure 

of deposits of Jackson age. The depos ts of 

Jackson age in this county are almost e tirely 

calcareous, consisting-of blue clay of the fu ler's.:. 

earth type, sandy marl, and bryozoan-b aring 

limestone, overlain by red sand which b longs 

largely to the Vicksburg formation. 

Ainstie.-An excellent exposure of t e Ti...; 

vola tongue of. the Ocala limestone occ s on 

the east side of Shells tone Creek 1 i mile east 

of Ainslie. The following section is ad pted 

from that given by Brantly: 2 

1 Berry, E. W., The Upper Cretaceous and Eocene floras 

Carolina and Georgia: U. S. Geol. Survey Prof. Paper 84, p. 13 , 1914. 

.2 Brantly, J. E., Georgia Geol. Survey Bull. 21, p. 21, 1916. 

Section on Weatherly place, on east side of Shellstone Creek, 

I 11- miles east of Ainsl~e. 

Residual Oligocene or Eocene: 

Vl·cksburg or Barnwell formation: Feet. 

6. Red argillaceous sand to top of escarpment. No sharp line of contact between 

this and the underlying bed............ 40 

Eocen,e: 

Blarnwell formation (Twiggs clay member): 

I 5. Cr=~~::e;.!~l.lee.'. e.~. (w.eathered), 20 o lcala limestone (Tivola tongue): 

4. Hard pinkish, partly crystalline limestone. 1 

3. Medium hard white, highly fossiliferous 

limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

2. Soft white porous, friable, highly fossiliferous limestone. . . . . . . . . . . . . . . . . . . . . . . 15 

1. Creek bottom land.. .. .. .. .. .. .. .. .. .. .. 3 

84 

~e foll~win~ fossils from the Weatherly 

plac were Identified by C. W. Cooke: 

Uppe 1 foot of bed 3: 

Periarchus sp. 

Semele? sp. 

Lowe , 1 foot of heel 3: 

Lunulites sp. 

Flabellum wailesii Conrad? 

Enclopachys maclurii (Lea)? 

Dentalium sp. 

Leda multilineata Conrad. 

Panope sp. 

Crassatellites sp. 

Bed 2: 

Bryozoa (Rich Hill facies of Jackson fauna). 

Periarchus pileus-sinensis (Ravenel)? 

Pecten perplanus Morton. 

D ese property.-Limestone and calcareous 

fullet's-earth beds of Jackson age are well 

expored on _the property of J. T. Deese on ~he 

soutleast s1de of Shellstone Creek, 10 miles 

nort~ of Cochran. The beds show local variations, but the following section, ~easured in a 

gull near the Deese residence, may be taken 

as t~pical. . 

Section on Deese property, near Shellstone Creek. 

Oligo)ene or Eocene: 

· Vl~·cksburg or Barnwell formation: 9. R:~~:~ o~~ ~~~t- ~~~~~~~ . ~~ . ~~~. ~~~ 50 

Eoce e: 

B rnwell formation (Twiggs clay member): 

Fee);. 

8. Blue calcareous fuller's earth, thin bedded, 

fossiliferous, more sandy than the underlying beds........................... 3 
76 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Eocene-Continued. 

Barnwell formation-Continued. Feet. 

7. Thin bed of hard impure fossiliferous limestone, probably. . . . . . . . . . . . . . . . . . . . . . 2 

6. Blue calcareous fuller's earth weathered to 

light yellov-rish gray at the surface. . . . . . 20 

5. Blue calcareous fuller's earth, containing 

harder and more calcareous layers.. . . . . 10 

4. Blue calcareous fuller's earth, almost free 

from sand and grit... . . . . . . . . . . . . . . . . . . 20 

3. Concealed intervaL . . . . . . . . . . . . . . . . . . . . 10 

2. Interbedded hard massive blue argillaceous limestone and blue calcareous 

fuller's earth. (These are varying 

phases of the same formation, the hardness depending on the percentage of 

calcium carbonate).................... 5 

1. Rotten fossiliferous limestone. . . . . . . . . . . . 5 

125 

The base of this section (altitude, about 300 

feet above sea level) is about 10 feet higher 

than the top of the Tivola tongue of the Ocala 

limestone exposed in the escarpment of Shellstone Creek 1! miles northwest of the Deese 

residence and is stratigraphically above it. 

HOUSTON COUNTY. 

The deposits of Jackson age present considerable diversity in Houston County. The 

Ti-vola tongue of the Ocala limestone enters the 

county from the south, with a thickness estimated by Brantly 1 at 45 feet. Its outcrop 

forms a narrow belt across the south-central 

part of the county to Grovania, and the principal exposures are in the steep escarpments 

along the south side of Indian Creek and its 

tributaries. From Grovania the limestone 

North of Perry red sand extends &hove the 

Cretaceous-Eocene unconforn1~ty to a maximum thickness of 50 feet. This bed probably 

corresponds in stratigraphic position with the 

yellow unconsolidated sands underlying the 

Tivola tongue of the Ocala limestone but may 

belong to the Midway formation. 

Sections at Ross Hill and Mossy Hill, near 

Perry, are discussed on pages 44-46. 

In the quarry of the Planters Limestone Co., 

near the crossing of the Georgia Southern & 

Florida Railway and the Perry-Fitzgerald 

branch of the Dixie Highway, 2 miles south of 

Tivola station, the following section is exposed: 

Section in Planters Limestone Co.'s quarry, 2 miles south of 

Tivola. 

Eocene: 

Barnwell formation (Twiggs clay member): Feet. 

2. Calcareous cream-colored clay resembling 

fuller's earth, grading downw~rd into 

argillaceous marl. This material starts 

at the top of the hill southeast of the 

quarry and is exposed in bare washes on 

the slope. There are conspicuous harder 

and more calcareous ledges 20 and 22 

feet above the base of the member. The 

marl at the base contains numerous Bryozoa, with Ostrea trigonalis and Pecten 

perplanus, but the upper fuller's-earth 

beds are not fossiliferous............. . . . 33 

Ocala limestone (Tivola tongue): 

1. Soft to medium-hard light cream-colored 

to white porous bryozoan limestone, exposed from the lowest point in the quarry to the top of the working face. . . . . . . 39 

72 

outcrop swings northward along the Georgia 

Southern & Florida Railway to Bonaire and In a gully along the railroad siding near the 

occupies an area more than 10 miles wide quarry and probably not more than 5 feet 

between the railway and Ocmulgee River. below the bottom of the pit, there is an expoThe Tivola tongue appears to be absent sure of 7 feet of medium-grained :rellow sand. ' 

north of Perry, but it has probably been re- The top of t~e Creta?eous can no~ he far below. 

moved from that area by erosion, for outliers 1 The follow~ng fossils were obtained from bed 

of the bed occur farther north at Rich Hill 1 of the sectiOn: ' Crawford County. 

The Tivola tongue of the Ocala limestone is 

overlain by the Twiggs clay member of the 

Barnwell formation, which in this county 

consists principally of calcareous cream-col-. 

ored clay resembling fuller's earth, forms the 

upper slopes of the Indian Creek escarpment 

and of other hills, and attains a thickness of 

about 100 feet. 

1 Brantly, J. E., op. cit., p. 82. 

Station 7689. Quarry 2 miles south of Tivola. Cooke and 

Shearer, collectors. 

Orthophragmina, stella~ely marked species. 

Lepidocyclina. sp. 

Bryozoa (Rich Hill fauna). 

Periarchus pileus-sinensis (Ravenel): 

Cypraea fenestralis Conrad? 

Mesalia? sp. 

Ostrea-sp. 

Pecten perplanus Morton. 

Panope sp. 

Protocardia nicolleti (Conrad)? 
DEPOSI'l'S OF CLAIBO NE AND JACKSON AGE IN GEORGIA. 

~he fos~ils from Rich Hill; -listed by T. 

77 

CRAWFORD COUNTY. 

The interesting occurrence of strata o Jackson age at Rich Hill, 6 miles east of R berta, 

has been well described by Veatch a d Stephenson.1 The variability of the strat , indicating deposition near the shore, is illu. trated 

by the following additional sections de cribed 

by Shearer: · 

Section in a gully on the north side of Rich 

Eocene: 

Barnwell formation: Feet. 

4. Dark-red argillaceous sand, w· h 

thin beds of plastic clay near t e 

base............................ 30 

Twiggs clay member: 

3. Fuller's-earth horizon. At the b se 

the clay is greenish, coarse grain d, 

and fossiliferous; at the top, m s.: 

sive, rather plastic, and stain d 

by iron deposited from percol t:-

ing water. . . . . . . . . . . . . . . . . . . . . . . . 25 

2. Unconsolidated yellow sand, gr ding upward into fossiliferous y 1~ 

low sandy clay, which here rep ·esents the Tivola tongue of t e 

Ocala limestone .... , ............ . 10· Unconformity. 

Lower Cretaceous: 

1. Kaolinic sand with a lens of massi e 

kaolin at the top~ .. " ....... · ..... 100+ 

Section in a gully ~n the south side of Rich 

Eocene: 

Barnwell formation (upper part): Feet. 

8. Dark-red argillaceous sand, 

thin beds of plastic clay near t e 

base ........................... ·. 40 

Twiggs clay member: 

7. Fuller's-earth horizon. The clay is 

light greenish yellow in color, v y 

slightly calcareous at the top . b t 

becoming more so toward t e 

base............................ 10 

Ocala limestone (Tivola tongue): 

6 . . Hard massive argillaceous li estone........................... 3 

5; Soft massive argillaceous limesto e, 

with few if any fossils.......... . . 7 

4. Bryozoan limestone of varying ha d.: 

ness. This is the bed from whi h 

the fossils listed below were c 1-

lected. ...... .................... 10 

3. Sandy marl (gradational phase): . . . ! 

Barnwell formation (basal part): 

2. Unconsolidated light-yellow sand.. 25 

Unconformity. 

Lower Cretaceous: 

1. Kaolinic sand with lenses of massi e 

kaoHn ............... : ...... ,,· .. .. 100+ 

1 Op. cit., pp. 299-300. 

28288°-19-6 

· ' 

195+ 

Vaughan In the Coastal Plain report,2 are as 

follbws: · 

Periarchus pileus-sinensis (Ravenel). 

Plejona sp. 

Calyptraea aperta (Solander). 

Ostrea georgiana Conrad, 

Pecten perplanus M'0rton. 

Pecten. (probably P. nuperus Conrad), young and 

poor specimen. 

Venericardia sp. 

Lucina sp., found also 5! miles south of Perry. 

Panope sp. 

'fhe calcareous beds of the preceding·. sectiofs are of undoubted Jackson age, and the 

Bryozoa of the Rich Hill facies of the Jackson 

faufa, as identified by R. S. Bassler, form 

. vai:uable h~rizon markers. 

The unconformity on the south side of the 

hiU is 25 feet lower than that on the north 

sid~, showing . an erosion depression in the 

Cr~taceous surface, and in this depression_the 

sand and limestone beds representing . the 

Oc~la are much · thicker than over the old 

hil tops . . The base of the .deposits 0f Jackson 

ag~ here is consider~bly higher than at any 

point in Houston or Twiggs counties, but the 

ex 1ct altitude is not known. The altitude of 

the top of the hill is probably about 700 feet. 

OCALA LIMESTONE. 

AREA NORTH OF DOOLY COUNTY. 

he local details of the Ocala limestone in 

the area north of Dooly County have been 

giv n in the preceding discussion of the Barnwe* formation and will not be repeated here. 

The type locality of the Tivola tongue of the 

Ocal

1

la limestone is descr.ibed on page 76. 

DOOLY COUNTY. I 

The Twiggs clay. member of the Barnwell 

forfuation extends southward from Houston 

CoJnty into Dooly pounty but becomes increasingly calcareous and merges into the Ocala 

lim~stone . The 11ivola tongue of the Ocala 

lim stone is well developed in Dooly County 

and has been seen at a number of natural 

ex~osures. On the J. M. Carter property, It miles southeasr of Lilly, 20 fe~t or more of soft white limestone composed l~rgely of Bryozoa but contai4ing also P ectef perplanus and P e'riarch~ 

2 Georgia Geoi.! Survey Bull. 26, p. 300, 1911. 
78 SHORTER 0~)-NTRIBUTIONS TO GENERAL GEOLOGY, 1918 •. 

pileus-sinensis is exposed. Brantly 1 reports 

20 feet of limestone overlain by 17 feet of 

calcareous fuller's earth on the L. Frieden property, 9 miles east of Montezuma. 

EXPOSURES ON AND NEAR FLINT RIVER; 

Strata of Jackson age first appear in the 

banks of Flint River about 3! miles above the 

crossing of the Seaboard Air Line Railway west 

of Cordele. From this point exposures occur 

at short intervals to Fort Scott, about 11 miles 

above the confluence of Flint and Chattahoochee rivers. As most of the exposures show 

little diversity, detailed discussion here will be 

restricted to those which have furnished the 

best collections of fossils or which are otherwise of interest. 

The lithologic variation in the Ocala limestone, as displayed along Flint River, is slight. 

In the upper reaches of the river the rock 

which presumably constitutes the lower portio~ of the formation, is prevailingly finer grained 

and less harsh in texture than that farther 

south, where tests of Foraminifera and Bryozoa 

compose a large proportion of the limestone. 

Above Albany.-The following fossils were 

obtained from the Ocala limestone on Flint 

River 3 miles above the Seaboard Air Line 

Railway bridge: 

Station 7106. Flint River at mouth of Spring Creek, 

Sumter County. Brantly and Cooke, collectors, 1914. 

Orbi toid Foraminifera. 

Flabellum wailesi (Qonrad)? 

Schizaster floridanus Clark? 

Turritella sp. 

Nucula sp. 

Pecten perplanus Morton. 

Crustacean. 

The Ocala limestone exposed at this locality 

consists of about 14 feet of white or creamcolored limestone in thin beds, alternating in 

· degree of hardness and containing a little glauconite. Analysis of the rock shows 85.8 per 

cent calcium carbonate. 2 · 

A quarter of a mile below this point the following fossils were . obtained: 

Station 7107. West bank of Flint River a quarter of a 

mile below the mouth of Spring Creek. Brantly and 

Cooke, collectors. 

Orbitoid Foraminifera. 

Bryozoa. 

Periarchus, probably P. pileus-sinensis (Ravenel). 

Mitra? sp. 

Pecten perplanus Morton. 

Amusium ocalanum (Dall). 

1 Brantly, J. E., op. cit., p. 112. 

2 Idem, p. 120. 

The last two species named were f<>und also 

at the railroad bridge below Spring Creek 

(station 7108). · 

At a small quarry on the Averitt pr~perty, 

300 or 400 yards southwest of the corner of 

lots 7 and 26, half a mile east of Hugunen 

Ferry and 1 I?ile south of Daphne station, Crisp 

County (statiOn 7237), the rock is a soft white 

limestone containing Orthophragmina fiintensis 

Cushman, numerous Bryozoa, and an undetermined pecten, probably Amusium ocalanwm 

(Dall). An analysis of the limestone from this 

loca~ty given by Brantly3 shows 85 per cent 

calCium carbonate. Better exposures of this 

rock occur in a sink about 300 yards east of 

the quarry, where 23 feet of soft argillaceous 

white limestone containing small specks of 

glauconite is overlain ·by 18 feet of reddish 

sandy loam. The course of an underground 

stream that flows through this sink can be 

traced northwestward by means of long, narrow slot-shaped sinks which expose it at intervals to Gum Creek. 

· The following section, which was measured 

by J. E. Brantly and C. Wythe Cooke on the 

east bank of Flint River 1 mile above the mouth 

of Cedar Creek, Crisp County, is quoted with a 

few minor changes from Brantly's report on 

the limestones and marls of· Georgia:' 

Section of Limestone Bluff on Armstrong place. 

Pleistocene: 

11. Sands and graveL ....................... . 

Ft. in. 

7 0 

Ocala limestone: 

10. Mostly concealed, but with several small 

exposures of soft white, finely granular 

limestone and hard, partly crystalline 

light-gray limestone. Bryozoa, Pecten, 

etc................................... 8 

9. Hard, very light gray crystalline limestone ..... _._ ... _._ .................... . 

8. Alternating 6 to 10 inch layers of soft and 

slightly harder white, finely granular 

limestone .. ~ ........ _ . . . . . . . . . . . . . . . . . 1 

7. Hard, very light gray crystalline limestone ................................ . 

6. Alternating 6 to 10 inch layers of soft and 

slightly harder white, finely granular 

limestone... . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

5. Medium-hard white, partly crystalline 

limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

4. Soft white limestone.................... 4 

3. Hard white limestone containing Bryozoa; forms a projecting ledge........... 4 

2. Soft light-gray limestone, with specks of 

glauconite and a few nodules of chert... 8 

a Idem, p. 158. 

4 Idem, p. 159. 

0 

3 

6 

3 

6 

0 

0 

0 

0 
DEPOSITS OF CLAIBORNE A~D J" ACKSON AGE . IN ~ G;EORGIA. 79 

Ocala limestone-Continued. 

1. Hard white, partly crystalline limestone, 

irregularly weathered, to water's edge 

at 2-foot stage. Contains (station 7110) 

Lunularia distans and other Bryozoa, 

Flabellum, Nucula, Glycymeris, Pecten, 

Amusium ocalanum, and Crassatellites. . 2 

I 

On the east bank of Flint River at the bend 

to the west 6 miles below Burke Ferry and 

about 6 miles above the bridge of the Georgia 

Southwestern & Gulf Railway, near Warwick,! 

Worth County (station 7115), the material! 

exposed consists of white compact limestone 

rising 5 feet above water level and overlain by 

flint boulders, sand, and gravel. Orihophragmina fiintensis Cushman and Operculina sp. 

were collected here. 

The section at a bluff on the west bank of I 

Flint River about 1! miles above the bridge! 

of the Georgia Southwestern & Gulf Railway is 

aB follows: 

Section in bluff on west bank of Flint Ri'ver. 

Feet. 

3. Covered slope to top of hilL. ................ 1

• 221 

Ocala limestone: 

2. Hard ledges of compact white semicrystalline 

limestone (station 7117).................... 3 

1. Compact white limestone, mQI3tly soft blft 

with harder places. Contains (station 7116) 

Orthophragmina flintensis and Laganum? 

crustnloides (Morton)? To water level at 

4-foot stage ................. 7 • • • • • • • • • • • • • 20 

From bed 2 (station 7117) were collected the 

following: 

Foraminifera: 

Orthophragmina flintensis Cushman. 

Bryozoa: 

Several species. 

Echinodermata: 

Laganum? crustuloides (Morton)? 

Mollusca: 

Ostrea sp. 

Pecten perplanus Morton. 

Pecten suwaneensis Dall. 

On the east bank of Flint River in Worth, 

County near the Dougherty County line, about 

16 miles above Albany (station 7119), the 

rock consists of 5 feet of limestone, the upperl

1 

part white, lower part gray, overlain by flint 

fragments. It contains Orthophragmina jlintensis Cushman, Operculina sp., and Pecten 

suwaneensis Dall. On the east bank of Flint 

River in Dougherty County, about 8 milesl 

above Albany, at the mouth of a small creek 

(station 7235), the following fossils were ob-I 

tained from soft white limestone, 8 feet in 

exposed thickness, .containing concretionary 

masses of hard limestone: 

Bryozoa. 

Laganum? crustuloides (Morton). 

Schizaster floridanus Clark? 

Macropneustes mortoni (Conrad)? 

Ostrea sp. 

Pecten perplanus Morton. 

Pecten suwaneensis Dall. 

Vicinity of Albany.-The following section 

was observed in the bank of Kinchafoonee 

Creek at the power plant 2 miles north of 

Albany: 

Section on Kinchafoonee Creek 2 miles north of Albany. 

Feet. 

4. River sands............................. . . . . 15 

Ocala limestone: 

3. Hard pink or yellow limestone with Cidaris 

georgiana and Amusinm ocalannm.......... 2! 

2. Hard pinkish limestone with Bryozoa, echinoids, and Amusinm ocalanum. . . . . . . . . . . . . 2! 

1. White, cream-colored, or yellow granular limestone with Amusinm ocalanu:m and casts of 

corals. To water level in Kinchafoonee 

Creek ................................... . 5 

Above bed 3 there is reported to be 5 feet 

of limestone which was inaccessible at the 

time this section was measured. Other sections at this locality that do not differ materially from this have been recorded by Veatch 

and Stephenson 1 and by Brantly.2 

The fossils in the following list were collected 

from loose blocks on the dump heap below the 

dam at the power plant: 

Station 7121. Excavation below dam at power plant on 

Kinchafoonee Creek 2 miles north of Albany, Ga. 

Cooke and Brantly, collectors, 1914. 

Foraminifera: 

Operculina sp. 

Echinodermata: 

Cidaris georgiana Twitchell. 

Cassidulus (Rhynchopygus) depressus 

Twitchell? 

Cassidulus (Pygorhynchus) conradi (Conrad). · 

Eupatagus carolinensis Clark? 

Linthia wilmingtonensis Clark? 

Macropneustes mortoni (Conrad). 

Mollusca: 

Eucymba ocalana Dall. 

Cypraea fenestra.lis Conrad . 

. Ostrea sp. 

Gryphaeostrea sp. 

Pecten perplanus Morton, varieties. 

Amusium ocalanum :Pall. 

Mya? sp. 

1 Veatch, Otto, and Stephenson, L. W., op. cit., p. 316. 

2 Brantly, J. E., op. cit., p. 135. 
80 SHOR.TER CONTRIBUTIONS TO GENERAL GEOLOGY, 1918. 

Between Albany ana Red Bluff.~The following fossils were found in white, gray, or creamcolored limestone extending about 2 feet above 

water level. 

Station 712:5. West bank of Flint River in Baker County 

about 3 miles below Dewberry Ferry (Baconton Landing) and about 13 miles above Newton. Brantly and 

Cooke, collectors, 1914. 

Flabellt).m sp. 

Cypraea fenestralis Conrad. 

Cerithium sp. 

Turritella sp. 

Calyptraea sp. 

Glycymeris sp. 

Pecten perplanus Morton. 

Pecten indecisus Dall. 

Amusium ocalanum (Dall)? 

Spondylus sp. 

Plicatula, Ocala sp. 

Venericardia sp. 

The following species were collected from 

lumps of hard limestone excavated from the 

channel: 

Station 7126. East bank of Flint River at Dry Breacl 

Shoals, Mitchell County, 8! or 9 miles below Newton. 

Foraminifera: • Orthophragmina mariannensis var. papilla:ta 

Cushman. 

Orthophragmina georgiana Cushman. 

Anthozoa: 

Trochoseris n. sp. 

Echinodermata: 

Cidaris georgiana Twitchell. 

Laganum? crustuloides (Morton)? 

Oligopygus haldermani (Conrad). 

Mollusca: 

Mitra sp. 

Chama sp. 

Limopsis sp. 

Barbatia sp. 

Ostrea trigonal is Conrad. 

Amusium ocalanum (Dall). 

Pecten perpl-anus Morton. 

Spondylus sp. 

Plicatula, Ocala sp. 

Mya? sp. 

Venericardia vicksburgiana Dall. 

Venericardia sp. 

Crassatellites sp. 

Station 7127. Loose blocks excavated from the channel of 

Flint River, a quarter of a mile below Norman's Ferry, 

Mitchell County, midway between Newton and Bainbridge. Cooke and Brantly, collectors, 1914. 

Lepidocyclina sp. and other Foraminifera. 

Lunularia sp. and other Bryozoa. 

Cidaris georgiana Twitchell. 

Oligopygus haldermani (Conrad). 

Laganum sp. 

Cypraea sp. 

Station 7127-Continued. 

Xenophora sp. 

Glycymeris sp. 

Barbatia sp. 

Amusium ocalanum (Dall) var. 

Spondylus sp. 

Lima halensis Dall. 

Plicatula, Ocala sp. 

Chamasp. 

Crassa telli tes sp. 

V enericardia sp. 

Mya? sp. 

On the east bank of Flint River in Decatur 

County, 1 mile below Windell's Landing and 

about 15 miles above Bainbridge (station 7129), 

Orthophragmina mariannensis var. papillata 

Cushman and an undetermined species of 

Pecten were found in 5 feet of irregularly 

weathered pinkish limesto:p.e. 

Vicinity of Bainbridge.-The Ocala limestone is the oldest formation in the vicinity of 

Bainbridge, and all its exposures appear to 

represent a single horizon. It is a soft, coarsely 

granular limestone varying in color from white 

to yellow and composed largely of tests of 

Foraminifera and Bryozoa, which on exposed 

surfaces have become firmly cemented or 

' 'case-hardenedJ' into a brittle, semicrystalline' 

limestone, but which when freshly exposed are 

only slightly coherent. The rock appears to 

lie v.ery nearly horizontal, but the upper surface is exceedingly irregular and jagged, with 

pinnacles extending in places to 20 feet 

above water level. ·The irregularity is due in 

part to erosion prior to the deposition 

of the overlying materials and in part to 

subsequent solution. The Ocala is overlain 

unconformably by a complex series of red and 

variegated sands and carbonaceous clays containing chert fragments with impressions and 

siliceous pseudomorphs of mollusks and corals 

of lower Oligocene age. The Ocala itself appears to have been subjected to the silicifying 

agencies to a lesser extent, for chert fragments 

carrying Ocala fossils are only occasionally 

found. The accidental inclusion of some of 

these in the collections of the coralliferous 

chert has unfortunately been interpreted as a 

mingling of the Ocala and Chattahoochee 

faunas. 1 

The following species have been identified 

from localities ne~r Bainbridge: 

1 Dall, W. H., A contribution to the invertebrate fauna of the Oligocene 

beds of Flint River, Ga.: U.S. Nat. Mus. Proc., vol. 51, p. 488, 1916. 
DEPOSITS OF CLAIBOR.NE AND JACKSON AGE IN GEORGIA. 81 

Station 7099. East bank of Flint River half a mile above Btation 7097-,.-Continued. 

Red Bluff. C. Wythe Cooke, collector. Bryozoa: 

Foraminifera: About 34 species, most of them new. 

Orthophragmina georgiana Cushman. Echinodermata: 

Bryozoa: Cidaris georgiana Twitchell. 

Many species. Cassidulus (Pygorhynchus) co'nradi (Conrad). 

Echinodermata: Oligopygus haldermani (Conrad). 

Oligopygus haldermani (Conrad). Agassizia conradi (Bouve). 

Agassizia conradi (Bouve)? Eupatagus carolinensis Clark? 

Stations 3387, 6159, 7098. Red Bluff, Flint River, 7 miles Mollusca: 

above Bainbridge. Vaughan, Stephenson, and Cooke, Ostrea, 2 sp. 

collectors. Pecten perplanus Morton. 

Foraminifera: Amusium ocalanum (Dall). 

Orthophragmina americana Cushman. Plicatula, Ocala sp. 

Orthophragmina mariannensis Cushn;tan. Cardi urn sp. 

Orthophragmina georgiana Cushman. Stations 3293, 6171. Bainbridge. A. H. Brooks and L. W. 

Orthophragmina vaughani Cushman. Stephenson, collectors. 

Bryozoa: Lepidocyclina sp. and other Foraminifera. 

Many species. Bryozoa, many species. 

Echinodermata: Cidaris georgiana Twitchell. 

Oligopygus haldermani (Conrad). Cassidulus (Pygorhynchus) georgiensis Twitchell. 

Laganum? crustuloides (Morton)? Oligopygus haldermani (Conrad). 

Cassidulus (Pygorhynchus) georgiensis Twit- Ostrea trigonalis Conrad. 

chell. Pecten perplanus Morton. 

Agassizia conradi (Bouve). Amusium ocalanum (Dall). 

Mollusca: 

Pecten perplanus Morton. 

Pecten indecisus Dall. 

Pecten suwaneensis Dall. 

Amusium ocalanum (Dall). 

Station 7097. Bluff on east side of Flint River near old 

factory three-quarters of a mile north of the Atlantic 

Coast Line Railway station at Bainbridge. Vaughan, 

Cooke, and Mansfield, collectors. 

Foraminifera: 

Orthophragmina georgiana Cushman. 

Lepidocyclina sp. and many others. 

EXPOSUI~ES WEST OF FLINT RIVER. 

For local details of the•Ocala limestone west 

of Flint River, the reader is referred to the 

county descriptions in Brantly's report on the 

limestones and marls of the Coastal Plain of 

Georgia. 1 

1 Brantly, J. E., Georgia Geol. Survey Bull. 21, 1916.