Bulletin No. 223^- ' - Series A, Economic Geology, 30

DEPARTMENT OF THE INTERIOR 

UNITED STATES GEOLOGICAL SURVEY

CHARLES D, WALCOTT, DIRECTOR

r

GYPSUM DEPOSITS

IN THE

UNITED STATES

BY

irG-EORG-E I. ADAMS AND OTHERS

WASHINGTON

GOVERNMENT PRINTING OFFICE

1904
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CONTENTS.

Page.

L. Letter of transmittal...................................................... 9

 Introduction, by George I. Adams.......................................... 11

'«, Geology, technology, and statistics of gypsum, by George I. Adams.......... 12

Properties of gypsum and theory of formation .......................... 12

.*. . Character of gypsum.............................................. 12

j Varieties of gypsum .............................................. 13

.f Anhydrite....................................................... 14

Associated minerals .............................................. 14

Formation of gypsum.............................................. 15

k Deposition of gypsum............................................. 15

Origin of rock gypsum............................................ 15

^ Origin of gypsum seams and veins................................. 16

Origin of gypsite or gypsum earth ................................. 16

 ^ Origin of gypsum sands........................................... 17

Geologic age of gypsum deposits................................... 17

r Technology .......................................................... 18

Theory of cooking or burning gypsum ............................. 18

Practice of cooking or burning in manufacture...................... 18

Theory of set of plaster ........................................... 18

Use of retarders.................................................. 19

Use of accelerators...................................1............ 20

. Hardening of plaster.............................................. 20

*» Hardening of natural gypsum...............................:...... 20

Description of processes of manufacture ............................ 20

'~ Historical sketch of the gypsum industry .......................... 24

Uses of gypsum .................................................. 24

Statistics............................................................. 25

Producing localities............................................... 25

Production by classes of product.................................. 26

X Production by States............................................. 26

Imports ......................................................... 31.

Gypsum deposits in New York, by Edwin C. Eckel. ....................... 33

Character and e.xtent................................................. 33

v Economic development............................................... 33

Geologic relations.................................................... 34

v Gypsum deposits in Virginia, by Edwin C. Eckel........................... 36

Character and extent................................................. 36 ^

Economic development............................................... 36

K Geologic relations ....................^............................... 37

Gypsum deposits in Ohio, by S. V. Peppel................................. 38

* Character and extent................................................. 38

Economic development..................... .............:............ 39

v Descriptions of localities.............................................. 40

Geologic relations,,,,.,.-..-...---................................... 4*

. . ' ' 3
CONTENTS.

Gypsum deposits in Michigan, by G. P. Grimsley ..................-......._ 45

Character and extent................................................. 45 *

Economic development............................................... 46

Descriptions of localities ............................................... 46

Geologic relations ............................................1....... 47 .A

Gypsum deposits in Florida, by David T. Day .............................. 48

Gypsum deposits in Iowa, by Frank A. Wilder............................. 49 ^

Character and extent................................................. 49

Economic development............................................... 50 S

Geologic relations.................................................... 51

Gypsum deposits in Kansas, by G. P. Grimsley.............;............... 53 A

Character and extent................................ 1................ 53

	^ Economic development............................................... 54

Descriptions of localities ............................................... 54

Geologic relations .....................................1.............. 59

Gypsum deposits in Oklahoma, by C. N. Gould............................. 60 ^ Character and extent................................................. 60

Economic development................................................ 61 >

Descriptions of localities .............................................. 62"

Kay County ...:...-...............-......................... 62 *

Main line of gypsum hills .................................... 62

Second gypsum hills.......................................... 63 *

Greer County region.......................................... 65 ^

Geologic relations :................................................... 66

Gypsum deposits in Texas, by Benjamin F. Hill............................ 68 -,

Character and extent................................................. 68

Economic development............................................... 69

Descriptions of localities ............................................... 70

Geologic relations ....'............ ............'........................ 73

Gypsum deposits in Montana, by Walter H. Weed.......................... 74

'Character and extent................................................. 74 *

Economic development............................................... 75

Geologic relations.................................................... 75

Gypsum deposits in South Dakota, by N. H. Darton........................ 76 .^

Character and extent................................................. 76

Economic development............................................... 78 *

Gypsum deposits in Wyoming, by Wilbur C. Knight....................... 79

Character and extent....'........................'..................... 79 >

Economic development................................................ 79

Descriptions of localities .........-......-.------...----.......-....... 80

Laramie Mountains ..--.....--...--.........-....-.......-... 80 _t

Medicine Bow Mountains..................................... 82

Rawlins uplift..............--....-......-.....-'.-..--....... 82 v

.Freezeout Hills ............................................... 82 .

Shirley Mountains .................-...................:...... 82 >

Seminole Mountains........................................... 82

Ferris Mountains.............................. ^............... 82 " 

Rattlesnake Mountains ....................................... 83

Connant Creek.......-...---.....----......---...........-... 83

Grand Canyon of the Platte................................... 83 ¥

Bighorn Mountains........................................... 83

Owl Creek Mountains ..........'................... ........... 84

Absaroka Mountains- . ,..,---,.,,..,.,. ,- --.,--,- ,--»---, 84
CONTENTS. 5

Gypsum deposits in Wyoming, by Wilbur C. Knight Continued. Page. 

^ Descriptions of localities Continued.

Prior Mountains........................:...................... 84

\Vind Eiver Mountains....................................... 84

K Gros Ventre Mountains....................................... 84

Salt Creek Eange.....'.......................................-. 84

V Black Hills.................................................. 85

Geologic relations ...... ..................'............................. 85

*' Gypsum deposits in Colorado, by Arthur Lakes ............................ 86

Character and extent................................................. 86

/° Economic development................................................ 86

I Descriptions of localities............................................... 86

Geologic relations.................................................... 88

Gypsum deposits in New Mexico, by H. N. Herrick ........................ 89

Character and extent................................................. 89

* Geologic occurrence ....... '. .... .'. .................................... 90

Descriptions of localities.............................................. 91

* Eastern New Mexico ...i...*..................................... 91

Lower Pecos Valley .......................................... 92

f Plain west of the Upper Pecos.................................. 92

Coyote Creek ................................................ 92

* Southeast of Las Vegas........................................ 93

y Bio Grande Valley or central region............................... 94

Chama Valley.............................................'.... 94

<- Headwaters of Rio Puerco and Bio Jemez...................... 94

East of Sandia Mountains......'...........--................... 95

East of Manzana Mountains and Socorro ....................... 95

Valley of the San Jose........................................ 96

Valleys of Bio Salado and Alamosa............................. 97

Begion of the Oscuro and San Andreas Mountains.............. 98

** . The white sands.............................................. 98

v Zuni or Western region............................................ 99

Gypsum deposits in Arizona, by William P. Blake.......................... 100

«.. Character and extent. ................................................ 100

Gypsum deposits in Utah, by J. M. Boutwell............................... 102

* Character and extent................................................. 102

Economic development............................................... 102

*" Nephi deposits............................................... 102

Salina deposits ............................................ i.. 103

White Mountain deposits ..................................... 103

 South Wash deposits ......................................... 104

Descriptions of localities .............................................. 104

« Nephi deposits............................................... 104

Salina deposits............................................... 107

* White Mountain deposits ..................................... 107

South Wash deposits ...................................:..... 107

*" Geologic relations ..................................................... 108

Nephi deposits............................................... 108

Salina deposits............................................... 109

., White Mountain deposits ...................................... 109

South Wash deposits .......................................... 110

Y. Gypsum deposits in Oregon, by Waldemar Lindgren........................ Ill

Character and extent................................................. Ill

* Economic development...............................................' Ill

Geologic relations .....:.............................-.... ............ Ill
6 CONTENTS.

Page.

Gypsum deposits in Nevada, by George D. Louderback .........-.........;. 112

Character and extent................................................. 112

Economic development............................................... 113

Geologic relations .................................................... 116

Gypsum deposits in California, by H. W. Fairbanks........................ 119 j

Character and extent................................................. 119 f

Economic development............................................... 120 ]

Descriptions of localities .............................................. 120 ^

Alamo Creek.....................'............................ 120 ;

Amboy beds ................................................. 120 ^

Antelope Valley..-......'...................................... 120 ;

Banning..........................'........................... 120 *

Bitterwater deposit............................................ 120 i

Coalinga mine................................................ 121 "^

Cottonwood Creek ........................................... 121 ^

Gypsum Canyon ............................................. 121

Kettleman Valley ............................................. 121 >;

Paoli mine................................................... 121

PointSal ..................................................... 122 ^

OjaiValley ................................ ............... 122

San Joaqiiin Valley mine ..................................... 122 *'

Santa Barbara Canyon........................................ 123 v

Sunset district................................................ 123

Geologic relations.................................................... 123 ^

Index................................................................... 125
ILLUSTRATIONS.

Page. 

^ PLATE I. A, Selenite which has been split and bent to show cleavage and

slight flexibility; B, Selenite crystals........................... 14

v II. A, Fibrous gypsum from a fissure in clay; B, Specimen of selenite

an inch thick, illustrating transparency and incipient cleavage.. - 16 

-1 ' HI. A, Aggregate of impure gypsum crystals from gypseous marl bed;

B, Spongy gypsum formed as a secondary deposit................ 18

IV. A, Massive gypsum showing mottled structure; B, Massive gypSUlll

showing banded structure ..................................... 20

V. A, Gypsum having serrate surface due to rain erosion; B, Rock gypsum which shows effects of solution ............................ 22

VI. Map showing producing localities in United States................. 24

V, VII. Map showing area of Salina group in central New York and gypsum-producing localities....................................... 34

r VIII. Geologic map showing gypsum deposits in southwestern Virginia,

near Saltville .............................. '. .................. 36

IX. Map showing gypsum deposits in vicinity of Port Clinton and

Sandusky, Ohio............................................... 38

X. A, View of south side of Fletcherville gypsum quarry; B, View of. 

north side of Fletcherville quarry.............................. 40

XI. A, Exposure at north end of Marsh and Company's quarry; B, 

+ Exposure of gypsum in old quarry of Marsh and Company....... 42

XII. Geologic map of gypsum-bearing area at Fort Dodge, Iowa ........ 50

*- XIII. Map showing gypsum deposits and the approximate limits of the

Permian in Kansas............................................ 54

* XIV. Map showing gypsum deposits in Oklahoma ....................... 60

XV. A, Glass Mountain, -Woods County, Okla., capped with massive

* gypsum; B, Escarpment capped with gypsum ledges, Red River

P.. ' Valley, Greer County, Okla.................................... 64

XVI. A, Butte of Red Beds capped with gypsum east-northeast of Cambria,

* Wyo.; B, Bluff showing gypsum bed 1 mile northwest of Plot

Springs, S. Dak ............................................... 78

* XVII. Map of Wyoming, showing distribution of Red Beds, which are

gypsum bearing at many localities.............................. 80

*' XVIII. View of the white sands, New Mexico............................ 98

XIX. A, Rock gypsum deposit 1 mile east of Nephi, Utah; B, Bed of gypsum on mesa 15 miles north of King City, Monterey County, Cal. 102 

^ XX. Exposure of gypsum and limestone in open cut at Lovelocks, Nev.,

the deposit showing folding and crumpling ..................... 116

* XXI. Map of southern California showing gypsum localities ............. 120

FIG. 1. Forms of gypsum crystals.......................................... 13

* 2. Section at Hurd gypsum mine, Linden, N. Y.......................... 34

3. Section from east to west showing relations of Salina group in New

* York........................................................... 35

7
8 ILLUSTRATIONS.

Page.

FIG. 4. Section across Holston and Saltville valleys on a northwest-southeast \ 

line, midway between Saltville and Plasterco, Va ................. 37

5. Section showing relations of gypsum on Soldier Creek, Iowa......... 50

6. Section at Great Western gypsum mine, Blue Eapids, Kans., showing

relation of gypsum to Cottonwood limestone ....................... 55

7. Section at Solomon gypsum mine, Kansas, s......................... 56

8. Section of Medicine Lodge Hills, 7 miles southwest of Medicine

Lodge, Kans.................................................... 58 .-^

9. Section near the gypsum mill at Ferguson, Blaine County, Okla..... 62

10. Section southeast of the salt plain in Woodward County, Okla....... 63 ^

11. Section of a butte 5 miles southeast of Cloud Chief, Okla ....:....... 64

12. Section of a bluff 3 miles south of Carter, Eoger Mills County, Okla 64 *

13. Section of bluff on Salt Fork, 10 miles south of Mangum, Greer County,

Okla........................................................... 65 >

14. General section of the rock formations of Oklahoma................. 66

15. Map of Texas showing location of areas containing principal deposits

of rock gypsum................................................. 68 ^

16. Map showing gypsum-bearing formations in the Black Hills of South

Dakota and northeastern Wyoming .............................. 77

17. Section on Cold Brook three-fourths mile northwest of Hot Springs,

S.Vak ...............:......................................... 78 - *

18. General section of Bed Beds in southeastern Wyoming, showing usual

position of gypsum................................................ 81

19. Section showing the relations of gypsum in the section south of ^ 

Laramie, Wyo................................................... 81

20. Transverse section of foothills strata on Deer Creek, Colorado ........ 87

21. Diagrammatic section through a portion of the Enterprise blanket,

showing relation of the gypsum to the blanket, Rico, Colo......... 88 -*,

22. Map of New Mexico showing approximately the area of the Bed Beds,

which are gypsum bearing at numerous localities.................. 89 ^

23. Diagrammatic section north of Lucero, N. Mex., in valley of Coyote

Creek.......................................................... 93 *

24. Section west of Nacimiento Mountains, New Mexico................. 94

25. Section northwest of Pyramid Mountain, New Mexico............... 95

26. Section at Pyramid Mountain, New Mexico, showing basalt cap lying ^

on gypsum ..................................................... 96

27. Section at Mesa Gigante, north of Bio Jose, N. Mex................. 96 *

28. Section at Rita, N. Mex., 8 miles east of Laguna..................... 96

29. Section northeast of El Bito station, New Mexico, showing basalt *

dike penetrating the gypsum-bearing series ....................... 97

30. Section of bluff in Bio Salado, 30 miles west of Belen, N. Mex........ 97 ~*

31. Map showing extent of White Mountain, Utah,' gypsum deposit...... 104

32. Sketch map of a portion of Nevada showing gypsum deposits which

have been developed............................................ 114
LETTER OF'TRANSMITTAL.

DEPARTMENT OF THE INTERIOR,

UNITED STATES GEOLOGICAL SURVEY, 

. Washington, D. C., November IS, 1903.

SIR: I have the honor to transmit herewith the manuscript of a 

report on the gypsum deposits of the United States, with the recommendation that it be published as a bulletin.

The report consists of a comprehensive summary of existing knowledge regarding the gypsum deposits of the United States, compiled 

by Mr. George I. Adams, with the collaboration of numerous other 

geologists, who have prepared chapters on the gypsum deposits of the 

several States. Through the assistance of these experts the report 

contains not only a summary of all published information on the subject, but much additional information not elsewhere available. 

Very respectfully,

C. W. HATES,

Geologist in Charge of Geology. 

Hon. CHARLES D. WALCOTT,

Director United States Geological Survey.

9

GYPSUM DEPOSITS IN THE UNITED STATES.

INTRODUCTION.

By GEOKGE I. ADAMS.

^ In this bulletin an attempt is made to set forth such information as 

is available concerning the gypsum deposits of the United States and 

their economic development. Much of the information may be found

* in technical and scientific journals, in the geologic and statistical 

reports of the States, and in the publications of the United States 

Geological Survey. Some of these publications, however, are now

y out of print. The individual chapters relating to the deposits in the 

various States have been prepared by members of the United States 

Geological Survey, who have studied them incidentally while engaged 

in broader or allied problems, or by other scientists who have devoted 

considerable time and energy to the subject. The gypsum deposits of 

the country have never been made a subject of exhaustive inquiry.

r It has not been possible to do special field work, except in certain 

localities, and hence the descriptions of deposits are not uniform. 

Another reason for the variation in the chapters relating to the indi-

«~ vidual States is found in the diverse conditions of development in the 

different regions, since the progress in exploration and the study of 

the conditions of occurrence can not go much in advance of the com-

\ mercial demand.

Many interesting details have been omitted, since the bulletin covers a wide scope and must necessarily be concise. It has been deemed

». advisable to specially emphasize the economic conditions, and accordingly the geologic relations of the deposits and theoretical questions 

are not extensively treated. The writer discusses briefly the techf- nology of gypsum, and considers in a general way the questions pertaining to its occurrence and utilization. The statements concerning 

the economic development are based on information which he has 

obtained in collecting statistics for the division of mining and mineral 

resources of the United States Geological Survey.

^

11
GEOLOGY, TECHNOLOGY, AND STATISTICS OF GYPSUM. 

By GEORGE I. ADAMS.

PROPERTIES OF GYPSUM AND THEORY OF FORMATION. 

CHARACTER OF GYPSUM.

Gypsum is a hydrous calcium sulphate. Its chemical composition 

is expressed by the formula Ca.SOt.2H2O, which may be interpreted 

as calcium united with sulphuric acid and holding water of crystallization. The percentage of these materials by weight is calcium 32.5, 

sulphuric acid 46.6, water 20.9. The mineral is not infrequently 

impure, as the result of other substances present during its formation 

or deposited subsequently in intimate relation with it. These impurities are usually organic matter, iron compounds, clayey material, and 

the carbonates of lime and magnesia.

The color of gypsum when reduced to powder is white. In its 

natural form, when pure, it is usually white when massive, and pearly 

or glistening when crystallized, the crystalline form being transparent, 

sometimes to a remarkable degree. Gypsum is often gray, flesh-red, 

honey-yellow, ocher-yellow^ or blue. As the result of impurities it 

may be brown, red, or reddish brown, and sometimes black.

The hardness of gypsum varies from 1.5 to .2.0, the crystalline form 

being taken as the standard for the second degree in the scale of hardness of minerals. It can be scratched with the finger nail, which is the 

common test applied to distinguish it from other minerals that have 

a similar appearance.

The specific gravity of gypsum, i. e., its weight as compared with 

pure water, is 2.3. At a temperature of 26° C., which is practically 

the ordinary temperature, one part of gypsum is soluble in 372 parts 

of water. As a matter of comparison it may be stated that at the 

same temperature 40 parts of common salt will dissolve in 100 parts 

of water. The presence of other salts in solution, as common salt, 

and especially potassium salts, increases the amount of gypsum 

which may be dissolved. When heated sufficiently gypsum gives off 

its water of crystallization and becomes opaque, being altered to 

anhydrite. It does not dissolve in sulphuric acid, and when acted on 

by other acids does not effervesce or gelatinize. It fuses, coloring the 

flame reddish yellow. When ignited at a temperature not exceeding 

260° 0. it will again combine with water and set. 

12
ADAMS.] GYPSUM DEPOSITS IN THE UNITED STATES. 13

VARIETIES OF GYPSUM.

Crystallized gypsum, or selenite, as it is called, when pure is colorless and transparent. It occurs in distinct crystals or broad and often 

large folia or sheets. Typical forms of gypsum crystals are shown in 

PL I, J?, and fig. 1. The cleavage of gypsum parallel to its principal 

plane is perfect. (See PI. II, £.) Along the cleavage planes gypsum 

separates into thin plates, which are flexible to a limited degree but 

not elastic. This characteristic serves to distinguish gypsum from 

mica, with which it is sometimes confused under the improper name 

of isinglass. Selenite and its massive form gypsum may be readily 

distinguished fromcalcite and its massive form limestone by the difference in hardness, since calcite and limestone can not be scratched with 

the finger nail.

Fibrous gypsum (see PI. II, J.), or satin spar, is a crystalline variety, 

having a pearly appearance.

Massive or rock gypsum (see PI. IV), in which the crystals are minute, 

even microscopic, is usually white. It not infrequently occurs in thick

FIG. 1. Forms of gypsum crystals, a, b, common; c, d, twinned.

strata interbedded with limestones and shales. Rock gypsum may 

contain, as impurities, clay, carbonate of lime, and silica, and so be 

variable in color. When fine grained and suitable for carving and 

sculpturing, it is known as alabaster. This variety is slightly 

translucent.

Earthy gypsum, or gypsite, as it is sometimes called, is not compact. 

It may be granular like sugar, or may occur in beds having an earthy 

texture. Such beds are usually near the surface, and are often very 

impure.

Gypsum sand occurs in some regions where rock gypsum is abundant, and is formed by wind erosion. It accumulates in dunes, in which 

it is mixed with fragmental material from other rocks.

Many natural waters contain gypsum in solution, having derived it 

from the rocks and soil through which they have passed. PI. V, B, 

represents a mass of rock gypsum that shows the effects of solution. 

Such waters are called permanently hard; that is, they will not soften 

when boiled in the ordinary manner, or, more accurately, they retain 

the gypsum in solution after being boiled. The solubility of gypsum
14 GYPSUM DEPOSITS IN THE UNITED STATES.. [BULL.223.

in water decreases after a certain temperature is reached, owing to the 

formation of anhydrite. To this fact is due the formation of boiler 

scale when gypsum is present in water used for boiler supply. Water 

which is hard because it contains lime or calcium carbonate is rendered 

soft when boiled, through the precipitation of the lime as the result A 

of the loss of the carbon dioxide which holds it in solution. Gypsum 

water is commonly stated to be undrinkable. As a matter- of fact, 

gypsum has very little effect on the human system. The ill effects ^ 

commonly attributed to gypsum water are due to the magnesium sulphate which it contains, this chemical being a common constituent of 

gypsiferous rocks. Gypsum is precipitated from water over the sur- A 

face of the soil, and in this process other salts are commonly produced. 

The injurious results due to the efflorescence or white incrustation on 

soils where large quantities of water evaporate should be attributed to ^

other minerals than gypsum.

>

ANHYDRITE.

4

Anhydrite has the same chemical composition as gypsum, with the 

exception that it contains no water of crystallization. By the absorp- * 

tion of moisture it changes to gypsum. This process occurs in nature, y 

and results in the alteration of beds of anhydrite to beds of gypsum. 

Anhydrite may be distinguished from gypsum by its crystalline ^ 

cleavage, which is in three rectangular directions, giving it a pseudocubic aspect. It sometimes occurs in formations which contain gypsum, and not infrequently is associated with beds of rock salt.

Anhydrite may be formed from gj^psum solutions at various temper- ^ 

atures when the solutions contain certain other salts in sufficient 

quantities. For example, it has been found that in the presence of a 

saturated solution of common salt this change takes place at 30° C., ^ 

which is a temperature reached in a summer day. This fact satisfactorily accounts for the formation of anhydrite in nature from concentrated sea water or lake brines. +

Anhydrite in gypsum deposits affects the calcined product much 

the same as the addition of so much dead-burned gypsum would.

 a

ASSOCIATED MINERALS.

In regions where gypsum deposits occur beds of rock salt are not 

infrequently found interstratified with the gypsum-bearing series. ^ 

The association of gypsum and rock salt is due to the fact that they 

have had a similar origin, the general opinion in regard to them being 

that both have been formed by the concentration of sea water. >

Sulphur deposits are occasionally found in intimate relation with the 

gypsum beds, and sometimes there is evidence that limestones have 

been in part altered to gypsum through the action of sulphate solu- > 

tions. In certain fields where petroleum occurs the association of sulphur and gypsum, and occasionally of rock salt, has been noted. These
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. 1

A. SELENITE WHICH HAS BEEN SPLIT AND BENT TO SHOW CLEAVAGE AND 

SLIGHT FLEXIBILITY.

B SELENITE CRYSTALS.
ADAMS.] ORIGIN OF GYPSUM. 15

cases are of much theoretical interest. The gypsum is accounted for 

by the reaction on limestone of the sulphate solutions derived from the 

oxidation of sulphides, such as pyrite. The reduction of gypsum 

through the agencies of decomposing organic matter, such as may have 

given rise to the petroleum, may have produced the sulphur.

FORMATION OF GYPSUM.

Gypsum may be formed in the laboratory by the chemical action of 

sulphuric acid on carbonate of lime. In nature this reaction may take 

place in a number of ways. Lime is quite universally distributed in 

the rocks.

Unimportant quantities of sulphuric acid form in nature by the 

oxidation of sulphurous acid and hydrogen sulphide. Sulphurous 

acid is known to escape from volcanoes and about fumaroles. The 

chief source of sulphuric acid, however, is . the oxidation of certain

sulphides, of which pyrite is the most abundant. Hydrogen sulphide, 

produced by decomposing organic matter or evolved by living organisms, is another source of sulphuric acid. Gypsum when formed may 

pass directly into solution or may form films and thin veins in the 

shales or other rocks which carry the pyrite. Sometimes free crystals 

are developed.

DEPOSITION OF GYPSUM.

The deposition of gypsum as a direct result of the processes which 

take place in its formation has given rise to only limited bodies 

occurring widely disseminated within the earth's crust. It is concentrated into economic deposits through water transporting it in solution. There are no chemical reactions necessarily incident to its precipitation from a solution. Although gypsum is not readily soluble 

in water, when once in solution it is held until evaporation causes it to 

be deposited. It is due to this fact that the circulatory ground water 

transfers it to the point of issuance of springs or into ponds and 

streams, from which it is carried into lakes and the ocean. When, 

through evaporation, these bodies of water are concentrated, the gypsum may be deposited. The processes of solution and redeposition 

may be repeated indefinitely.

ORIGIN OF ROCK GYPSUM.

The mode of origin of rock gypsum maj^ be inferred from the fact 

that the beds are usually interstratified with shales, sandstones, and 

limestones which have been deposited in seas or lakes. The gypsumbearing series are usually destitute of fossil remains, showing that the 

water had reached a degree of concentration which was unfavorable to 

life. Not infrequently the presence of iron oxide causes the associated 

rocks to have a red color. Such sediments are believed to have been 

derived from land areas which were deeply oxidized. The study of
16 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

the broader stratigraphic relations of the gypsum series usually shows 

that they were formed in local basins, and probably in landlocked 

arms or remnants of retreating seas. Beds of rock salt which are 

thought to have had a similar origin are sometimes found in the gypsum-bearing series; and this occurrence throws some light on the concentration of the sea brine which contained the various chemical salts 

in solution.

ORIGIN OF GYPSUM SEAMS AND VEINS.

Where jointing or fissuring has opened passageways for water 

through gypsum-bearing rocks, and where the water has circulated 

along the bedding planes, the gj^psum which it holds in solution often 

crystallizes in seams and veins, which may be clearly seen to be of 

later origin, since they not infrequently cut the beds of gypsum. 

Large masses of selenite which are remarkable for their transparency 

and specimens of satin spar which have beautiful fibrous, pearly 

luster, are commonly formed in this way. The force of crystallization is not well understood, but it is apparent that in many instances 

it is powerful enough to lift rock masses and widen fissures. Where 

initial deposition of gypsum has taken place the crystal growth of 

the mass in the fissure may continue, and eventually result, by further 

widening of the fissure and increased growth of the mass, in the 

formation of large bodies. Just how much importance should be 

given to this method of deposition can not be stated, since it is a 

subject which has received but little attention.

ORIGIN OF GYPSITE, OR GYPSUM EARTH.

Gypsite, or gypsum earth, is usually found in regions where beds 

of rock gypsum occur, and it is probable that they have been derived

from these primary deposits through the circulation of ground water. 

The spring theory of origin has been advanced by Mr. G. P. Grimsley, 

who has studied the deposits in Kansas, which were the first of this 

class to be utilized. The gypsite is found upon microscopic examination to consist of small, angular, gypsum crystals, some of which are 

perfect, but most of them have their terminations rounded by solution. 

This shows that they are not transported ciystals, but are found in 

place. Mingled with them there are small quartz crystals and a considerable amount of poorly ' crystallized calcite, besides traces of 

organic matter. The position of the deposits with respect to the beds 

of rock gypsum and the location of them in low ground are favorable 

to the theory that they have resulted from the evaporation of spring 

water or solutions issuing in swampy places. In working the gypsite 

deposits springs are encountered which are troublesome when the 

gypsite is being removed. The presence of recent fresh-water shells 

associated with the deposits shows that they are of late origin,
U. S. GEOLOGICAL SURVEY

A. FIBROUS GYPSUM FROM A FISSURE IN CLAY.

B. SPECIMEN OF SELENITE AN INCH THICK, ILLUSTRATING TRANSPARENCY AND 

INCIPIENT CLEAVAGE.
ADAMS.] AGE OF GYPSUM DEPOSITS. 17 

ORIGIN OF GYPSUM SANDS.

Many of the gypsum deposits in the western part of the United 

States are in relatively arid regions, where wind erosion is actiye. The 

disintegrating gypsum is carried by the wind with other detrital material and mingled with the surface deposits. This process does not 

usually give rise to economic bodies, but in certain localities there are 

gypsum sands which are of exceptional purity and of considerable 

extent. The most noted occurrences are the gypsum dunes in Utah, 

which were described by Mr. G. K. Gilbert, and the area' known as 

the white sands in southern New Mexico,. which has been described 

by Prof. C.. L. Herrick. These areas are fully discussed below. The 

dunes of gypsum in New Mexico cover, irregularly, about 350 square 

miles. The area is one in which the stream and surface waters are 

impregnated with various salts. Evaporation produces an efflorescence or crust which, when it disintegrates, is blown by the winds into 

dunes. The more soluble salts are dissolved by the falling rains, but 

the gypsum, which is relatively insoluble, accumulates, and has given 

rise to the so-called white sands. In this region gypsum deposits are 

interstratified with the bed-rock series. The origin of the sands is in 

some respects not unlike the origin of the gypsum earth described 

above, but differs in the mode of accumulation.

GEOLOGIC AGE OF GYPSUM DEPOSITS.

Gypsum deposits occur in the rocks of practically every geologic 

system. Of those which are of economic value, the oldest known in the 

United States are found in Silurian rocks, in the central part of New 

York, in northern Ohio, and in the Upper Peninsula of Michigan. 

"The next younger are the deposits of the Mississippian, or Lower Carboniferous series in Virginia, in the Lower Peninsula of Michigan, 

and in Montana. By far the most extensive are those which were laid 

down during Permian time. They embrace the beds found in the 

Black Hills of South Dakota and of certain parts of the Rocky Mountains, and extensive deposits which occur in Iowa, Kansas, Oklahoma, 

Texas, and New Mexico. The geologic relations of some of the gypsum 

in the Western States is not definitely known. It is believed, however, 

that in the Rocky Mountain and Great Basin regions the gypsum is 

largely of Mesozoic age, some of it certainly belonging to the Jurassic. 

In Tertiary times deposits were formed in the western part of the 

United States, but because of the abundance and availability of the 

other deposits of gypsum in that region the Tertiary beds have not 

been developed, except in California.

The change of place of deposition with the progress of geologic 

time has been due to the shifting of the seas, as a result of the gradual

Bull. 223 04 2
1.8 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223. «

emergence and submergence of the continental mass. There does not 

appear to be much difference in the character of the gypsum formed - 

during the various periods, excepting as the purity was influenced by 

local conditions of sedimentation. r

!

TECHNOLOGY.

THEORY OF COOKING OR BURNING GYPSUM. :

j, The composition of gypsum -is CaSO^HgO. It is a hydrated sulphate of lime, consisting of one part of lime sulphate to two parts of ^ 

water. Careful experimentation has shown that when gypsum is heated 

to a temperature of about 132° C., it loses three-fourths of its water, 

and another hydrate is formed, having the formula (CaSOJ2 .H2O. 

Accordingly, calcium sulphate may be considered as having two hydrated forms. The first, which occurs in nature, is the more stable ^ 

one; the second, in which the amount of water is less, is converted ^ 

into the first when water is added to it. This hydrate is essentially 

plaster of Paris. .

If gypsum is heated to a temperature of 343° C., all the water is - 

driven off, and it is converted into anhydrite, which has the composition CaSO4 . This mineral exists in nature, and has a different crystalline form from gypsum. It is converted into gypsum on taking up *. 

water and recrystallizing. When it is produced artificially, it is 

a pulverulent mass, and is called dead-burnt plaster. If gypsum is 

heated to a sufficiently high temperature it fuses or melts, and on }.

cooling is glassy.

>

PRACTICE OF COOKING OR BURNING IN MANUFACTURE;

^

In the process of manufacture of plaster, when sufficient heat is , 

applied the water of crystallization of the gypsum is converted into

steam, the crystals. are broken up, and the mass boils vigorously. * 

When the temperature reaches about 132° C. the material ceases boiling, settles down in the kettles, and is seen to have a decreased volume 

as a result of the loss of water. As the temperature rises to 138° to * 

143° C. the mass again boils, losing more of the water of crystallization. When the temperature reaches about 177° C. the material is 

withdrawn from the kettles, the process of boiling being checked "* 

before a temperature is reached which is sufficiently high to drive off 

the water of crystallization from the whole mass; in other words, it is 

stopped when it has approximately the composition- of the second * 

hydrate, and before the plaster is dead-burnt, or reduced to anhydrite. ^

THEORY OF SET OF PLASTER. v

If a solution of gypsum is crystallized by evaporation the crystals >. 

which form do not interpenetrate, but form a granular mass, which 

resembles natural gypsum. Plaster of Paris, on the addition of water,
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL.

A. AGGREGATE OF IMPURE GYPSUM CRYSTALS FROM GYPSEOUS MARL BED.

B. SPONGY GYPSUM FORMED AS A SECONDARY DEPOSIT.
ADAMS.] PLASTEE OF PAEIS. 19

becomes fully hydrated and forms a mass of interpenetrating crystals. 

These two processes are quite different. The setting of plaster is a 

chemical process, the stable hydrate being formed from the unstable. 

In properly burned plaster there are fragments of the original crystals 

present which form starting points for recrystallization, and as a 

result a solid body is formed in which the needle-like crystals are interlocked in such a way as to give a good degree of hardness and a fine 

texture. If the plaster has been underburned it is not completely converted into the unstable hydrate, the gypsum'has not been reduced to 

proper fineness, and in setting crystallization produces a less uniform 

mass. If, 'on the other hand, the gypsum is overburned, so that there 

are no minute fragments or crystals to start the process of recrystallization, it will set slowly and less perfectly. Moreover, overburned 

plaster consists largely of anhydrite, which takes up water less readily 

than the unstable hydrate, which is the essential constituent of plaster

of Paris.

USE OF RETARDERS.

When water is mixed with plaster of Paris the plaster will set in 

from six to eight minutes. In order to delay this process and allow 

time for workmen to use or apply the plaster properly certain sub- 

. stances, known as retarders, are added. The retarders are added in 

the process of manufacture after the plaster has been burned, and 

should be thoroughly mixed with it. The amount is varied according 

to the time which must be allowed for using the plaster. The set 

may be held back so that it will not be complete until from two to six 

hours, or even a whole day, has elapsed. The action of the retarders 

is evidently to interfere mechanically with the process of crystallization, by preventing in a measure the molecular rearrangement of the 

plaster and to hold back the water which is essential to its hydration. 

To this end various substances are used, such as organic matter and 

various mineral substances, or a combination of both. When plaster 

is manufactured from a secondary deposit of gypsum or gypsite, as it 

is called, the impurities present may accomplish the retardation to the 

desired degree. The materials employed as retarders have a wide 

range in character, and include such substances as tankage from packing houses, glue, glycerin, molasses, sugar, ground peas, beans, or grain, 

sawdust, pulp, fiber, lime, slag, earths, alkalies, acids, etc., mixed in 

varying proportions, although some of them ma}r be used singly. The 

amount employed is small. The patented retarders commonly employed 

are mixed in the proportion of from 6 to 15 pounds to the ton of 

plaster. The effect on the texture and strength of the set plaster is 

very slight, and when substances are used which do not decay, and are 

employed in small amounts, the}r do not prove objectionable. .
20 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

USE OF ACCELERATORS.

When it is desired that plaster should set very quickly certain salts 

are mixed with it. As an example of the use of accelerators may be 

cited the addition of a small amount of alum or borax to dental plaster, 

in order to cause it to set promptly. The effect of the presence of 

crystals in a mixture of plaster of Paris and water may be seen when 

a small amount of old plaster has been left in the receptacle in which 

the mixture is made. The plaster already set starts the crystallization 

in the mass much sooner than it would otherwise begin.

HARDENING OF PLASTER.

It has been found that by the use of certain chemicals plaster may 

be rendered harder than when it sets in the natural way. These 

chemicals may be used either in the process of manufacture or after 

the plaster has set in the desired form. The hardening depends on 

the action of the chemicals on the lime carbonate which is present as 

an impurity in the plaster, converting it into calcium sulphate. In 

_case it is desired to effect this in the manufacture after the plaster has 

been burned, it is treated with a solution of alum, sulphuric acid, 

borax, or other chemicals, and reburned at a low heat. If it is desired 

to harden the plaster after it is set, the surface is sponged with a 

solution which, entering the material, produces the desired chemical 

change; or it may be saturated with oil or paraffine, which toughens 

it and allows it to be polished.

HARDENING OF NATURAL GYPSUM.

By a process similar to that employed in hardening plaster after it

has set, gypsum rock is made more durable, so that it can be used as 

a substitute for marble and other ornamental stones in finishing buildings. It is not employed to any large extent. The process usually 

consists of heating blocks of g37psum and driving out all the moisture, 

then allowing them to absorb a solution, after which they are reheated 

or dried. The result is a slight chemical change in the composition of 

the rock, giving it a denser texture and greater hardness.

DESCRIPTION OF PROCESSES OF MANUFACTURE.

The process of manufacture of gypsum products varies somewhat 

in the different parts of the United States, but in all cases follows 

practically the same methods. There are essentially two classes of 

plants those which use gypsum rock, and those which use gypsum 

earth. The gypsum earth requires much less machinery, since it does 

not have to be crushed, and can usually be obtained with less labor. 

The plants which use gypsum earth have the disadvantage of the
U. 8. GEOLOGICAL SURVEY :ULLET1N NO. 223 PL. IV

A. MASSIVE GYPSUM SHOWING MOTTLED STRUCTURE.

B. MASSIVE GYPSUM SHOWING BANDED STRUCTURE.
ADAMS.] MANUFACTURE OF GYPSUM. 21

deposits being local in character, and consequently being exhausted 

in the course of a few years. This necessitates the moving of the 

machinery or the transportation of the gypsum earth. The rock gypsum deposits are usually extensive enough to supply a large mill for 

many years.

The first step in the manufacture may be called the winning of the 

crude material. The g3^psum earth, or gypsite, is sometimes loose 

enough to be shoveled directly into wagons or tram cars. In other 

cases it is loosened with a disk harrow and wheeled away in scrapers. 

Because of its being quite moist, it is usually allowed to dry under 

sheds, in order to save the expense which would be entailed in driving 

off the water, and also because it will pass through the machinery 

more readily when dry and pulverulent. These deposits seldom have 

much overburden, and when they must be uncovered the material

which overlies them can be moved without the necess% of blasting.

The detrital material, such as soil and silt, is usually scraped up and 

dumped to one side or thrown into the pit. Steam shovels can be 

used to advantage in these deposits, although the equipment of the 

plant is seldom so elaborate.

Rock gypsum can be won most advantageously when it is exposed 

in surface ledges situated in bluffs, for it can then be transported 

by means of a gravit}^ tram, and the overburden and waste can be 

disposed of without much handling. Moreover, water does not stand 

in the quarries, as it frequently does in low ground. Rock gypsum, 

which is obtained at low levels, usually is quarried until the overburden is too great to be removed economically. After this it is 

mined. Pillars are left to support the roof, but in some cases timbering is resorted to, especially where the roof is weak. In the 

localities which have been worked for many years extensive underground workings have been made, and it is found advantageous to 

resort to shafts rather than to long hauls by means of trams. Considerable care is required in selecting the purer portions of the beds 

when they vary in composition. The impure grades of gypsum are 

sometimes utilized for land plaster.

Rock gypsum is usually delivered at the mill in pieces of convenient 

size for handling. It is then passed through crushers, which are essentially heavy jaws of chilled iron having a backward and forward motion. 

By means of them the rock is reduced to sizes which can be fed into a 

gyratory crusher. There are various styles of this machine, but they 

are all essentially of a pattern similar to a coffee mill, and they reduce 

the material to small fragments. The gypsum is next ground to a 

coarse powder by means of buhrs. For this operation buhrstones or 

rolls, such as are used in flour mills, are commonly employed. Special 

forms of machinery, known as disintegrators, have been invented. 

They consist of cages with short crossbars that travel in opposite
22 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

directions and beat, the rock into a powder by impact. The gypsum 

is next conveyed to the calcining kettles. These are of cylindrical 

shape, and are placed vertically within a jacket of brick or masonry 

work. The heat is applied from below, and there are usually flues 

which pass through the kettles. In the process of cooking the kettles 

are filled gradually, and the mass is stirred by means of revolving arms, 

which prevent the burning of the gypsum at the bottom of the kettle 

and also serve to distribute the heated material so that the mass has 

an even temperature. When the gypsum begins to cook, the water 

which is driven off causes it to boil vigorously. This boiling ceases 

when the temperature has reached about 132° C., and the mass settles 

a few inches in the kettles, as the result of the loss of water. As the 

temperature rises the gypsum boils once more, but less vigorously. 

At a temperature of about 177° C. the material is drawn .off by 

opening a gate at the bottom of the kettle. It falls into a fireproof 

bin, or onto a floor, where it is allowed to cool.

In the process of cooking the temperature is noted oy means of a 

thermometer inserted into the mass or placed within a tube which 

reaches into the kettle. Expert calciners, however, are able to judge 

the stage of the process by noting the appearance of the gypsum and 

the progress of the operation, which is conducted in a relatively 

uniform manner. In the first boiling of the gypsum the material is 

reduced to the condition of the second hydrate. In the second stage 

of boiling it is partially converted into anhydrite. It is essential for 

the manufacture of a good product that this should be checked at 

the right time, since if it is carried too far it is dead burned and will 

not set readily.

After the gypsum has been cooked and cooled it is bolted or passed 

through screens. Sometimes it is reground to a finer powder; otherwise the lumps and coarser portions are returned and worked a second 

time. The finished product is either stored or placed directly in 

hundred-pound jute or paper sacks or in barrels.

The best arranged plants are so constructed as to convey the gypsum 

by means of gravity spouts from the time that it enters the mill until 

it issues from the buhrs, and sometimes until it issues from the kettle. 

After is has reached a state of fineness which will permit of the operation, it can be conveyed by means of blowers. In other cases bucket 

elevators, or belt conveyors, are employed in raising it into bins, from 

which it is drawn off by gravity spouts.

When retardersare added they are mixed after the gypsum has been 

cooked and cooled. This is often done at the mill where the plaster is 

manufactured, but there are many firms in the United States which 

purchase calcined plaster and convert it into special brands of wall 

finish in their own mills. Sometimes, in addition to the retarder, kilndried sand and hair or other fiber is added in proportions which require
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. V

A, GYPSUM HAVING SERRATE SURFACE DUE TO RAIN EROSION.

B. ROCK GYPSUM WHICH SHOWS EFFECTS OF SOLUTION.
ADAMS.! MANUFACTURE OF GYPSUM. 23

simply the addition of water in preparing it for wall mortar. Plaster 

to which retarders have been added should not be stored for a long 

time, especially when the retarder consists of substances liable to 

decompose, or change chemically. It is also essential that moisture 

should be excluded, so that the plaster will not become hydrated.

The preparation of the finer grades of plaster of Paris and the manufacture of quick-setting plasters, such as dental plasters and special 

grades used in the arts, require a pure quality of gypsum and specific 

treatment of it. The simplest operation in the industry is the manufacture of land plaster, which requires only the grinding of the raw 

material.

In the earliest process gypsum was baked in ovens. This method is 

still in vogue in Germany and other European countries, but has been 

materially modified, so that it can be conducted on an extensive scale. 

It is considered necessary in the manufacture of certain grades of

plaster, especially that used in forming the molds employed in the 

making of porcelain, to have the gypsum uniformly calcined. Accordingly it is baked in ovens, since this method insures a more uniform 

heat.

American manufacturers are careful in cooking gypsum not to deadburn it, which renders it too slow-setting. In the German industry 

slow-setting plaster is largely in use. It requires more careful and 

extensive treatment in applying it, but it is claimed that its greater 

hardness renders it suitable for certain purposes for which ordinary 

American wall plasters can not be used. In this country Portland 

cement commonly takes its place, yet some manufacturers are producing gypsum-cement plasters which have a good degree of hardness 

and approach the German grades of slow-setting plaster. The Germans employ in the manufacture of this grade a vertical kiln very similar in construction to an ordinary limekiln. The fireplace is so 

arranged that the ashes fall into a pit and the flames and heat pass 

upward through the mass of gypsum. As the gypsum is burned the 

lower portion, when sufficiently calcined, is drawn off back of the 

grate, and the remaining mass settles down in the kiln. The process 

is accordingly a continuous one, and since there is no need of guarding against dead-burning in the manufacture of this grade, the process 

is satisfactory.

German manufacturers are to be credited with having made the 

greatest advance toward perfecting a continuous process for the manufacture of the ordinary grades of calcined plaster. When vertical 

kettles are used considerable time is required in filling and drawing 

off. To obviate this rotary kilns have been introduced, which are 

similar to those used in calcining Portland cement. There are, however, some differences in the process of burning gypsum and cement. 

A reducing flame must not be allowed to come in contact with the
24 GYPSUM DEPOSITS IX THE UNITED STATES. [BULL.223.

gypsum, since it would partially reduce it to calcium sulphide, which 

will not set. Moreover, the gypsum should not be discolored by soot 

or flame. Accordingly a blast of hot air is used instead of the direct 

blast of the furnace.

A method of cooking by means of superheated steam has been 

invented, but while the principle is an excellent one, the process has 

not -been sufficiently perfected, and the expense of fuel is relatively 

greater.

HISTORICAL SKETCH OF THE GYPSUM INDUSTRY.

The first deposits which were utilized in the United States were those 

in New York. This was at a time when the population was largely 

confined to the Atlantic coast. As settlement extended, the gypsum 

in Virginia, Ohio, and Michigan was developed, and later, that in 

Iowa, Kansas, and the Western States. On the Pacific slope the 

industry was at first largely confined to California. The deposits in 

the western part of the country are relative^ more extensive than in 

the eastern, but the industrial conditions at the present time are not 

such as to create a demand for the material. The statistics which are 

available for the early period show that in New York, Virginia, Ohio, 

and Michigan the manufacture of land plaster was an important branch 

of the gypsum industry. This was due to the theories of numerous 

writers on agriculture, which were printed in the newspapers of the 

early times, and which called attention to the beneficial effects of land 

plaster in restoring the fertility of worn-out land. While the use of 

land plaster has continued to be of about the same importance, the 

demand for wall plaster has greatly increased. This is due to the 

perfecting of the processes of manufacture, and to the growing demand 

for strong material in modern architecture. It is the use of gypsum 

as wall plaster which has led to the development of the deposits in the 

Western States, such as Iowa, Kansas, Oklahoma, and Texas, where 

the soil still retains its natural fertility.

USES OF GYPSUM.

Probably the first use made of gypsum was as plaster of Paris. Its 

application in the arts has been extended until it is now one of the 

important structural materials and is essential in many industries. 

Calcined gypsum w&y be classified as plaster of Paris and wall plaster. 

There are many special grades which are prepared for particular uses, 

but they are not enumerated here, since the names by which they are 

known in the market are largely trade or patented names. Plaster of 

Paris is used principally in modeling, and in forming molds and plaster 

ornaments, especially such as are used in interiors. By treating casts 

they may be made to withstand the weather, but in the United States 

terra cotta is more commonly used for exteriors. The use of plaster
U. S. GEOLOGICAL SURVEY BULLETIN N0.223 PL.VI

_ MAP 

OP THE

UNITED STATES SHOWING LOCALITIES WHICH PRODUCE

I'll ' . Scale iittl 1 !, -J«>

JULIUS BIEN S CO.L1TH.N.V
GYPSUM-PRODUCrtfG LOCALITIES. 25

of Parts as molds in the manufacture of porcelain is extensive, and in 

the plate-glass industry thousands of tons are required annually for 

bedding the glass during the process of grinding and polishing. It is 

also emploj^ed as a filler in paper and as a minor constitutent of some 

Portland cements. Some raw gypsum is used as a body for paint. 

Calcined gypsum prepared with glue and pigments is applied as a thin 

plaster to walls. This preparation is sometimes called alabastine. The 

use of gypsum as wall plaster is the most extensive one, and because 

of its adaptability it has largety displaced lime and sand mortar as wall 

finish. It is not improbable that the use of slow-setting plaster, 

having a greater degree of hardness, may be extended more widely, 

as has been the case in Germany.

Ground gypsum is sometime, s found as an adulterant in flour, and 

enters surreptitiously into many products. In agriculture ground

gypsum has two uses. The more important one is as land plaster, for

increasing the fertility of soils. Its action is not clearly understood, 

being one of the many unsolved problems relating to soil and its 

fertility. The theory is that in its decomposition and reaction with 

elements of the soil, potash is freed, which is needed by plants. 

According^, soils which contain soluble potash in abundance would 

not be benefited b}^ the application of gypsum. In the Western States 

there is considerable land which contains black alkali, or which upon 

being irrigated develops this substance in excess, so that it is injurious to the crops. Black alkali is a term applied to the carbonates of 

soda, potash, and magnesia. It may be neutralized by the application 

of land plaster to the soil. The chemical reaction which takes place is 

the-change of carbonates to sulphates, which are less injurious to plants.

STATISTICS. 

PRODUCING LOCALITIES.

During 1902 gypsum was produced in the following States and Territories: Michigan, Iowa, Texas, New York, Ohio, Kansas, Oklahoma, 

California, Wyoming, Colorado, Virginia, Utah, Montana, South Dakota, Nevada, and Oregon. The producing localities are shown on the 

accompanying map of the United States (PI. VI). From an inspection 

of the map it will be seen that the industry is well distributed, excepting in the southeastern part of the United States. In that region there 

are some deposits of gypsum known, but they are usually not important enough to justify extensive operations. The deposits in Florida, 

described elsewhere in this report, may prove to be of economic value.

At some of the localities the deposits have been worked for many 

years, at others they have just been opened; and in the newer parts 

of the country the industry is just established. At. a number of localities in New York gypsum is quarried for land plaster, but from these
26 GYPSUM DEPOSITS Itf THE. UNITED STATES. [BULL. 223.,

the production is small. Previous to 1902 gypsum was produced at a 

few localities which are now abandoned, either because of the exhaustion of the readily available material or because they were not advantageously situated with respect to market.

PRODUCTION BY CLASSES OF PRODUCT.

The production of gypsum is reported'as crude g.ypsum, land plaster, 

plaster of Paris, and wall plaster, which represent the conditions in 

which gypsum first reaches the market. The quantity and value of 

each of these classes and the totals for 1902 are set forth in the following table. For the sake of comparison the production for 1901, somewhat differently classified, is also given below. The total production 

is estimated as crude, while the total value is that of the product as it 

first reaches the market.

Production, value, and prices of gypsum in the United States, 1902.

Grade.

Crude ...-...--_.........._....-...._.......

Land plaster. ................................

Plaster of Paris .............................

Wall plaster ................................

Quantity.

Short tons. 

81, 455

60, 791

188, 702

350, 685

a 816, 478

Value.

$93, 914

106, 237

562, 928

1, 326, 262

2, 089, 341

Average 

price per 

ton.

$1.15

1.75

' 2.98

3.78

"Estimated as crude. 

Production, value, and prices of gypsum in the United States, 1901.

.Grade.

Crude ......................................

Calcined ....................................

Quantity.

Short tons. 

68, 669

59, 058

399, 686

a 633, 791

Value.

$71, 773

109, 551

1, 325, 317

1,506,641

Average 

price per 

ton.

$1. 05

1.85

3.31

a Estimated as crude. 

PRODUCTION BY STATES.

The production by States during 1901 and 1902 is shown in the following table. In order to avoid giving the product of individual 

plants, it has been necessary in some instances to combine the production of two or more States.
ADAMS.] PKODUCTION AND VALUE. 27

Production and value of gypsum in the Untied States in 1901, by States.

State.

California ....................

Michigan .....................

New York ....................

Virginia ......................

Other States ..................

Total...................

Total 

product.

Short tons.

3, 550 

17, 394 

213, 419 

185, 150 

119, 565 

15, 930 

15, 236 

63, 547

633, 791

Sold crude.

Quantity.

Short tons. 

3,550 

150 

2,750 

46, 086 

11, 678

1,054 

3,401

68, 669

Value.

$4, 200 

150 

3,575 

.47,986 

10, 908

1,104 

3,850

71, 773

Ground into land 

plaster.

Quantity.

Short tons.

16 

3,079 

9,808 

33, 591

9,675 

2,889

59,058

Value.

$62 

5,025 

10, 708 

61, 093

25, 995 

6,668

109, 551

State.

California ........................

Michigan .........................

New York ........................

Virginia ..........................

Other States .............. .......;

Total.......................

Calcined into plaster of Paris.

Before 

calcining.

Short tons.

17, 228 

207, 590 

129, 256 

74, 296 

15, 930 

4,507 

57, 257

506, 064

After 

calcining.

Short tons.

13, 595 

164, 720 

103, 933 

55, 273 

13, 205 

3, 752 

45, 208

399, 686

Value.

$76, 223 

620, 736 

208, 549 

169, 668 

66, 031 

18, 045 

166, 065

1, 325, 317

Total value.

$4, 200 

76, 435 

629, 336 

267, 243 

241, 669 

66, 031 

45, 144 

176, 583

1, 506, 641
28 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223. 

Production and value of gypsum in the United States in 1902, by States.

State.

California, Ohio, and Virginia. . 

Colorado and Wyoming .......

New York ............... ....

Other States ..................

Total...................

Total 

product.

Short tons.

101, 545 

16, 051 

295, 769 

240, 227 

110, 364 

34, 156 

18, 366

816, 478

Sold crude.

Quantity.

Short tons. 

2,360

957 

68, 885 

9,153

100

81, 455

Value.

$6, 790

1, 180 

70,460 

15, 184

300

93, 914

Ground into land 

plaster.

Quantity.

Short tons.

16, 357

4,331 

13,022 

25, 981

1,100

60, 791

Value.

$35, 450

6,497 

16, 340 

43, 750

4,2QO

106, 237

Colorado and Wyoming ...........

Oklahoma ....................:...

Other States .........-........._...

Total............... ........

Calcined ir

Before 

calcining.

Short tons. 

82, 828

16, 051

290, 481

158, 320

75, 230

34, 156

17, 166

674, 232

to wall plast 

of Paris.

After 

calcining.

Short tons. 

66, 263

12, 841

232, 385

126, 656

60, 184

27, 325

13, 733

539,387

er and plaster

Value.

$248, 153

73, 372

799, 678

372, 821

200, 236

111, 215

83, 715

1, 889, 190

$290, 393

73, 372

807, 355

459, 621

259, 170

111, 215

oo 91 c

2, 089, 341
ADAMS.] PRODUCTION AND VALUE. 29

The statistics of production by States are relatively complete since 

the Eleventh Census. The following table shows the production from 

1890 to 1900:

Production and value of gypsum, by Stales, 1890-1900.

California ..........

Colorado ...........

Iowa ...............

Kansas .............

Michigan ...........

New York ..........

Ohio ...............

South Dakota .......

Texas ..............

Utah...............

Total.........

California ..........

Colorado ...........

Iowa ...............

New York ..........

Ohio ...............

South Dakota .......

Texas ..............

Utah...............

Virginia ............

Wyoming ..........

Total.........

18£

Quantity.

Short tons. 

4, 249

4,580

20, 900

20, 250

74, 877

32, 903

12, 748

2,900

6,350

3,238

182, 995

189

Quantity.

Short tons.

21, 447

43, 631

124, 590 *

36, 126

11, 646

5,150

4,011

7,014

253, 615

0.

Value.

$29, 178

22, 050

47, 350

72, 457

192, 099

73, 093

87, 533

7,750

20, 782

22, 231

574, 523

3.

Value.

$55, 538

161, 599

303, 921

65, 392

39, 884

12, 550

13, 372

24, 359

696, 615

18£

Quantity.

ShOrt tons.

3,000

4, 720

31, 385

40, 217

79, 700

30, 135

9,123

3,615

3,000

5,959

1,992

212, 846

18?

Quantity.

Short tons. 

6

895

17, 906

64, 889

79, 958

175

31, 798

20, 827

1,300

4,295

6,925

1,920

8,106

312

239, 312

1.

Value.

$36, 360

19, 400

58, 095

161, 322

223, 725

58, 571

36, 586

9,618

15, 000

22, 574

6,200

647, 451

4.

Value.

$30

4,800

44, 700

301, 884

189, 620

1,820

60, 262

69, 597

7, 500

16, 050

27, 300

12, 225

24, 431

1,500

761, 719

189

Quantity.

Short tons.

1;500

12, 000

46, 016

139, 557

32, 394

13, 275

1,926

2,600

6.991

256,259

189

Quantity.

Short tons. 

5,158

1,371

13, 100

25, 700

72, 947

66, 519

33, 587

21, 662

6,400

10, 750

2,134

5,800

375

265, 503

2.

Value.

$1, 500

28,500

195, 197

306, 527

61, 100

49, 521

8,640

16, 300

28, 207

695, 492

5.

Value.

$51, 014

8,281

46, 125

'36, 600

272, 531

174, 007

59, 321

71, 204

20, 600

36, 511

11,484

17, 369

2,400

' 807, 447
30 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223. 

Production and valuer/ gypsum, by States, 1890-1900 Continued.

Arizona ............

New York ..........

Ohio...............

Oregon .............

Texas ..............

Utah...............

o

Wyoming ..........

Total.........

189

Quantity.

Short tons.

1,452

1,600

8,000

18, 631

49, 435

67, 634

385

23, 325

22, 634

6,115

16, 022

2,866

5,955

200

224, 254

6.

Value.

$11, 738

10, 547

24, 000

34, 020

148, 371

146, 424

1,940

32, 812

63, 583

20, 000

48, 070

13, 600

17, 264

975

573, 344

189

Quantity.

Short tons. 

30

351

, 1, 575

10, 734

29, 430

54, 353

94, 874

425

33, 440

18, 592

8,350

24, 454

2,700

6,374

3,300

288, 982

7.

Value.

$250

2,774

10, 305

40, 050

64, 900

189, 679

193, 576

2,300

78, 684

50, 856

19, 240

65, 651

13, 500

16, 899

7,200

755, 864

189

Quantity.

Short tons. 

30

3,800

165

24, 733

59, 180

93, 181

1,123

31, 655

21, 303

3,150

150

2, 740

34,215

2, 610

8,378

5, 225

291, 638

8.

Value.

$700

24, 977

726

45, 819

191, 389

204, 310

7,272

81, 969

61, 884

12, 000

450

9,200

58, 130

10, 080

23, 388

22, 986

755, 280
ADAMS.] IMPOETS. 31 

Production and value of gypsum, by States, 1890-1900 Continued.

Arizona ....................

California ..................

Colorado ...................

Iowa .........................

Kansas .....................

New York..................

Ohio....... ................

Oregon .....................

South Dakota ...............

Texas ......................

Utah.......................

Virginia ....................

Total.................

18

Quantity.

Short tons. 

47

2,950

' 871

12, 000

75, 574

85, 046

144, 776

582

52,149

27, 205

11, 526

550

550

53, 773

2,352

11, 480

4,804

486, 235

99.

Value.

$1, 200

14, 950

3,904

26, 000

296, 220

247, 690

283,537

3,698

105,533

73,520

36, 600

1,895

4,000

125, 000

10, 240

32, 043

21, 050

1,287,080

19

Quantity.

Short tons. 

35

3,280

967

6,500

184, 600

48, 636

129, 654

1,025

KQ OQfl

1,000

39, 034

18, 437

550

2, 050

80, 622

2,397

11, 940

4,845

594, 462

00.

Value.

$900

10, 088

5,300

15,000

561, 588

150, 588

285, 119

7,980

icft coo

4,805

119, 946

60, 380

1,710

13, 800

192, 418

4,984

18, 111

24, 229

1, 627, 203

IMPOETS.

From the following tables it will be seen that a large amount of 

gypsum is imported annually. It comes principally from Nova Scotia 

and New Brunswick and enters the ports of the Atlantic coast. Next 

in importance is the amount received from the peninsula of Lower 

California, Mexico, which enters at the port of San Francisco. The 

gypsum is usually shipped crude and is calcined in mills at the 

place of entry. Some of the imported material consists of the finer 

grades of plaster of Paris.
32 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223. 

Imports of crude, ground, or calcined (dutiable) gypsum, by countries.

Country from which imported.

France .................

United Kingdom. .......

Nova Scotia and New

Mexico .................

Total..............

19

Tons. 

132

190

259, 353

20

259, 695

02.

Value. 

$1, 902

1,854

275, 877

23

279, 656

19

Tons. 

185

93

196, 932

2,236

1

199, 447

01.

Value. 

$1, 311

987

216, 636

9,700

36

228, 670

19C

Tons. 

342

59

203, 347

1,014

88

204, 850

0.

Value. 

$2, 397

836

234, 563

4,500

602

242, 898

Imports of crude, ground, or calcined (dutiable) gypsum, by customs districts.

Customs district into which 

imported.

Bangor, Me. ............

Bath, Me...............

Passamaquoddy, Me. ....

Portland and Falmouth, 

Me...................

Boston and Charlestown, 

Mass ...-.......-...--

New Haven, Conn ......

New York, N. Y........

Newark, N. J ...........

Perth Amboy, N. J ......

Philadelphia, Pa ........

Baltimore, Md ..........

Norfolk and Portsmouth, 

Va......... .:.......

San Francisco, Cal ......

Other districts ..........

Total.............

19

Tons. 

57

235

703

8, 395

5,760

235

360

3,515

157, 699

30, 388

6,218

33, 343

 1,630

3,987

5,600

1,550

20

259, 695

02.

Value. 

.$148

141

429

7,628

11, 546

144

990

3,124

167, 444

35, 091

3,733

39, 471

960

3,040

4,815

930

22

279, 656

19

Tons. 

415

390

740

8,232

180

5,921

230

315

1,916

117, 989

19, 700

2,780

23, 900

1,387

5,635

, 7,480

2,236

1

199, 447

01.

Value. 

$796

234

446

7,942

135

11, 118

141

866'

1,325

138, 565

21, 751

1,661

25, 233

816

3,381

4,488

9J700

72

228, 670

190

Tons. - 

290

153

736.

9,503

6,450

284

3,942

121, 728

21,491

4,230

21, 216

2,325

3,822

5,715

2,000

1,014

32

204, 850

0.

Value. 

$448

92

966

10, 530

11, 925

688

2,818

150,074

22, 857

2,538

25, 828

1,401

2,834

3,746

1,320

4,500

333

242, 898
GYPSUM DEPOSITS IN NEW YORK. 

By EDWIN C. ECKEL.

CHARACTER AND EXTENT.

The gypsum in New York State occurs as rock gypsum interbedded 

with shales and shaly limestones. Several gypsum beds, separated by 

shales, usually occur in any given section. They are lenticular in 

shape, but of such horizontal extent that in any quarry they are 

usually of uniform thickness. Those that are worked vary from 4 to 10 

feet in thickness in most of the quarries, but at Fayetteville a 30-foot 

bed is exposed. The area in which the gypsum-bearing formations 

are found (see PI. VII) extends through the central part of the State, the 

productive portion of the belt including parts of Madison, Onondaga, 

Cayuga, Ontario, Genesee, Monroe, Livingston, and Erie counties.

Most of the deposits are too impure to be used in the manufacture 

of the finer grades of plaster of Paris, since they contain small amounts 

of earthy matter, lime, and iron. Until recently almost all the product 

was marketed as land plaster. Within the last few years, however, 

several large plants have commenced the manufacture of calcined 

plaster and wall plaster. The gypsum used in these plants is mostly 

obtained from Genesee County, where it seems to be of a higher grade 

than that which occurs farther east.

ECONOMIC DEVELOPMENT.

In the early history of the State gypsum was employed extensively 

as a fertilizer. This was largely due to the publicity given to its use 

by the numerous papers on the subject written by early authorities on 

agricultural topics. The development of the deposits exercised ,an 

appreciable influence on the gypsum industry of the United States, 

and led to exploration for it in other places.

Gypsum in New York is generally quarried at points where the 

overlying rocks have been thinned or entirely removed by erosion. 

In the area of the State where the deposits occur there is usually a 

thick covering of glacial drift, which disguises the bed rock and makes 

it difficult to discover the gypsum beds. At many of the localities the 

gypsum is obtained by quarrying. At a few places the beds have been 

followed under cover for some distance, the opening constituting a 

small mine, rarely more than 1 or 2 acres in extent. Where the material is obtained by this method the workings are timbered, or pillars 

Bull. 223 04 3 33
34 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

of gypsum are left at intervals to support the roof. The rock is 

hoisted hy cars operated by steam or drawn by horses. Occasionally 

in the workings places are found where the gypsum has been removed 

by solution, producing a sink, which has been filled by surface material 

which has fallen in.

The deposits are so extensive and so widely distributed that those 

which are favorably situated with respect to transportation facilities 

are abundantly capable of supplying the demand. Most of the openings which supply land plaster are located in the vicinity of the Erie 

Canal, or some of its branches, which affords a aheap means of transportation. The larger plants, especially those which manufacture 

calcined plaster, also have convenient railway facilities.

The most easterly points at which gypsum has been worked are in 

Madison County, but the quantity produced there is small just sufficient to supply the local demand for land plaster. In Onondaga 

County, at Marcellus, Fayetteville, and other places, large quarries

are worked, part of the

Gypsum, 5 ft 

Gypsum, i ft

Evenly bedded limestone, 

18ft.

Water limestone, 6 ft. 

Greenish nmrlite, 10 ft.

Dark gypsum, 1 ft.

Shale, 1 ft. 

Shale, 1 ft.

FIG. 2. Section at Hurd gypsuin mine, Linden, N. Y.

material being calcined 

and part ground for land 

plaster. The quarries 

near Union Springs, in 

Cayuga County, produce 

principally land plaster, 

as do those of Phillipsport, Gibson, and Victor, in Ontario County. 

At Mumford and Oakfield, however, there are

large quarries and plants which produce calcined plaster. Most of 

the gypsum obtained in western Genesee County and in Erie County 

is used locally as land plaster.

GEOLOGIC RELATIONS.

The gypsum-bearing formation occurs in~a series of shales an<i shaly 

limestones of Upper Silurian age. This series is called the Salina 

group. It is divisible in Onondaga County, where it has been studied 

in detail, into four parts. Beginning with the highest, these are:

1.. Magnesian limestones; argillaceous and with interbedded shales; 

utilized in the manufacture of natural cement in Erie County.

2. Gypsum beds, shales, and occasional beds of impure limestone.

3. Mottled red and green shales; shales with local, very small quantities of gypsum. This division carries the rock-salt beds of New York 

State, but owing to its ready solubility the salt is never seen in natural 

outcrop, being reached onty by shafts or drill holes.

4. Red shales; a thick series of red shales forming the base of the
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. VII

MAP SHOWING AREA OF SAUNA GROUP IN CENTRAL NEW YORK AND GYPSUM-PRODUCING LOCALITIES.
NEW YORK. 35

Salina group in Onondaga County. In going westward, however, 

these red shales rapidly diminish in thickness and disappear entirely 

before the western border of Wayne County is reached.

The main gypsum, deposits occur in the upper part of the Salina, as is 

noted in the divisions above outlined. The smaller occurrences in the 

lower horizons are of no economic importance. The association of 

the salt beds of this group at horizons below the gypsum is of interest, 

since it has a bearing upon the origin of the deposits, which are 

regarded as having been derived from water concentrated in inclosed 

basins, the concentration having been produced by evaporation.

The areal distribution of the rocks of the Salina group is shown on 

PL VII, taken from the new geologic map of New York State. No

fl? Horizon ^ ri H of the 3 S Oriskanv >* sandston

FIG. 3. Section from cast to west showing relations of Salina group in New York.

attempt has been made to show the four divisions of the group. It 

may be said in general that the gypsum outcrops along a line drawn 

a short distance north of the southern boundary of the Salina. The 

dip of the formations in this part of the State is generally to the south, 

at a low angle. Exposures and well sections, however, show that this 

dip is not continuous, but is reversed at intervals, giving local dips to 

the north. Cross folding is very marked in certain parts of the area, 

giving strong local dips to the east and west. The Salina beds, as a 

whole, have the form of an irregular lens, being thickest in the meridian of Ithaca, from which place they diminish in thickness westward 

and eastward (fig. 3). This fact has been demonstrated by plotting 

the sections as revealed b^ records of numerous drill holes.
GYPSUM DEPOSITS IN VIRGINIA. 

By EDWIN C. ECKEL.

CHARACTERS AND EXTENT.

All the workable gypsum deposits of Virginia occur in Washington 

and Smyth counties, in the valley of the North Fork of Holston 

River. The area within which the knoAvn deposits are located is a 

narrow belt about 16 miles in length, extending from a snort distance 

southwest of Saltyille to a point about 3 miles west of Chatham Hill 

post-office.

The material occurs as rock gypsum, interbedded with shales and 

shaly limestones of Carboniferous age. The beds of gypsum average 

30 feet in thickness at the localities at which they are now worked. 

The rocks of the district dip at a high angle, however, usually between 

25° and 45°, so that certain wells which have been drilled are in the 

gypsum for long distances, and accordingly immense thicknesses of 

gypsum have been erroneously reported, because the inclination of 

the deposits was not taken into account. Near. Saltville the dip of the 

gypsum beds which are worked is toward the northwest; at the mines 

farther up the valley the dip is to the southeast.

The Virginia gypsum, as shown by several analyses, is of remarkable purity, comparing favorably with that from Nova Scotia.

ECONOMIC DEVELOPMENT.

The development of the gypsum industry in this area has been governed almost entirely by the transportation facilities. The deposits 

in the upper valley, though extensive and easily workable, have not 

been largely exploited, owing to the long wagon haul necessary. The 

deposits at Saltville and Plasterco, which are on a branch of the Norfolk and Western Railroad, have furnished the principal output.

Throughout the entire area the dip of the gypsum beds is so high 

as to require mining, except at the commencement of the working.

The mines of the Buena Vista Plaster Company south of Saltville 

are the most extensive, exploitation having been carried to a depth of 

280 feet, and the lateral workings extending several hundred yards 

from the main incline. Timbering is used in places, but the principal 

reliance is on large gypsum pillars left at intervals. The gypsum is 

hoisted up the incline by a cable operated by steam power. The 

product is marketed partly as land plaster and partly as calcined and 

wall plasters. 

36
U. S. GEOLOGICAL SURVEY 

MAP SHOWING THE GYPSUM DEPOSITS " IN SOUTHWESTERN V

US B!EN & CO. N.Y
ECKEL.] VIBGINIA. 37

Openings near Saltville now filled with water were worked until 

1902 by a company which utilized the product in the manufacture of 

Keene's cement a at Glade Spring-. Farther up the valley gypsum, is 

mined on the property of John Barnes east of Laurel Creek, most of 

the product being ground for land plaster at a custom mill located on 

Laurel Creek.

The exposures covering the largest surface area ar.e those on the 

Buchanan property, between 1 and 2 miles north of Lament postoffice. The product is used entirely as land plaster, part being shipped 

in lump and part crushed at the custom mill above mentioned.

GEOLOGIC RELATIONS.

The gypsum beds of southwestern Virginia'occur interbedded with 

a series of shales and shaly limestones of Carboniferous age. UnderFIG. 4. Section across Holston and Saltville valleys on a northwest-southeast line midway between

Saltville and Plasterco, Va.

lying this gypsiferous series is a thick group of shales carrying 

heavy beds of rock salt. Overlying the gypsum-bearing shales is the 

Greenbrier limestone.

Throughout most of the region in question all these beds dip at 

angles of 25>0 to 45° SE. Near Saltville, however, a syncline is shown, 

capped \)y Greenbrier limestone. All the gypsum obtained at present in the vicinity of Saltville and at Plasterco station is from openings worked on the southeastern side of this syncline, and therefore 

the beds which are worked in this part of the district dip to the northwest.

A short distance southeast of the line of gypsum outcrops a fault 

has brought the Cambrian limestone up against the shaly limestones 

of the Carboniferous. No gypsum need be expected east of this fault 

line; but it is probable that exploration would show its presence af 

many points west of the fault line, between the localities now knowiv 

and worked.

The geologic map accompanying this paper (PI. VIII) is based on 

that published in 1884 by Prof. J". J. Stevenson, 6 with slight revision 

and addition of gypsum localities from field work by the writer.

"Engineering News, vol. 49, pp. 107-108. bTrans. Am. Phil. Soc., vol. 22, pp. 114-161.
'G-TPSUM DEPOSITS IN OHIO. 

By S. V. PEPPEL.

CHARACTER AND EXTENT.

The gypsum deposits of Ohio which are of economic value consist of 

beds of rock gypsum. They have been known since the first settlements 

were made on the northern shore of Sandusky Bay. The exposures 

lie at about the level of the waters of the bay, in some places rising a 

few feet above it In addition to the deposits of economic importance,. 

gypsum is found in small pockets and isolated bodies throughout the 

area of the Rondout (Waterlime) formation, which occurs extensively 

in northwestern Ohio. The deposits which are worked vary considerably in thickness, ranging from a few inches up to 9 feet. On the 

north shore of Sandusky Bay, in Portage Township, Ottawa County, 

1,500 to 2,000 acres of land have been thoroughly prospected with a 

core drill, and it has been shown that there are from 150 to 200 acres 

of workable gypsum. On the south shore of the bay, about 2i miles 

northwest of the town of Castalia, drilling has shown the presence of 

another area of workable gypsum, but no developments have }^et been 

undertaken. It is estimated that at the present rate of production the 

known deposits will last about twenty-five years.

The records of deep wells in other sections of the State have shown 

the presence of gypsum at a number of places. Prof. Edward Orton, a 

in discussing the gypsum-bearing formation of the State, says:

At various other points gypsum is found in the outcrops of the formation, and 

notably in the vicinity of Sylvania, Lucas County, while in the deep wells recently 

drilled through northern and central Ohio it is the exception to miss deposits of 

gypsum in the samples of drillings. The last case reported is 3 feet of pure fibrous 

.gypsum from a depth of 150 feet at Upper Sandusky.

In the deep well drilled in 1886 at Sandusky a bed 9 feet in thickness was reported 

by the driller at a depth of 272 feet. It was also reported in smaller amounts at 

other points in the next 800 feet of rock passed through by the drill.

The principal ledges of gypsum which are worked are of a grayish 

cast, due to the numerous fine wavy bands of carbonaceous material 

which run through it. There are occasionally thin shaly partings, 

having irregular courses through the gypsum rock. The gypsum 

itself is pure white.

«Geol. Survey Ohio, vol. 6, p. 697. 

38
U. 6. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. IX

GYPSUM DEPOSITS

IN THE VICINITY OF

PORT CLINTON AND SANDUSKY 

OHIO
OHIO. 89

ECONOMIC DEVELOPMENT.

At the present time two calcining plants are in operation in Ohio. 

One is at Metcherville, 1| miles southeast of Port Clinton; the other 

is three-fourths of a mile south of Gypsum station. It is reported 

that a third plant is to be erected in the near future by a company 

owning considerable deposits and having others under lease. The 

deposit on the south shore of the bay may eventually be developed.

In the beginning of operations the gypsum was won by open quarries. This necessitated the removal of from 15 to 25 feet of overburden, which consisted of earth, clay, and stone. Recently underground 

mining has been resorted to, the entrances for the most part being 

from the old workings. PI. X, J., shows the south side of the quarry 

at Fletchendlle, with three entry openings. PI. X, B, shows an entrance on the north side of the same quarry. Two shafts are in operation in the district. In the mines at Gypsum station three beds are 

worked. At Fletcherville the top bed is absent. The main bed is at 

present worked and the lower is undeveloped. Inasmuch as the gypsum lies at a low level there is considerable water, so that it is necessary 

to use pumps in the workings. The water that comes from the mines, 

as well as that found in most of the deep drill holes, is a potable water, 

highly impregnated with sulphuretted hydrogen. In prospecting on 

the south shore of the lake a strong flow of water was encountered, 

which fills the drill holes nearly to the top. The question has been 

raised as to whether the water would interfere with the working of 

the deposits. Inasmuch as the drill records show that in nearly every 

case the water is not encountered except below the lowest gypsum 

bed, it is reasonable to conclude that the heavier beds can be worked 

without unusual inconvenience if care is taken not to penetrate the 

lower formations. 

On the north shore of the bay one of the quarries has been abandoned, because the waters of the lake were let in through a crevice 

which was found in the workings. An attempt was made to build a 

dike in the bay and to pump the water out of the quarry, so that the 

gypsum close to the shore could be obtained. The experiment, however, was not successful.

The gypsum industry in Ohio has increased rapidly in the last few 

3^ears. The principal portion of the product is used for wall plaster. 

There are within the State eight companies which are engaged in the 

manufacture of hard wall plaster. Most of their material is obtained 

from Ohio. Next in importance is the use of plaster in the manufacture of plate glass. A considerable amount is employed in the making of crayons. Minor amounts are used in making pottery molds, 

in the manufacture of Portland cement, and as laud plaster.
40 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

DESCRIPTIONS OF LOCALITIES.

The deposits on the south shore of the bay, north of Castalia, were 

discovered several years ago in sinking a well. Recently a core drill 

has been used in prospecting the localitj^. Eight drill holes have 

shown an area of about 10 acres of good gypsum having considerable 

thickness. This lies at what is known as the Alfred Meggit farm. The 

driller reports the following record:

Drill record at Alfred Meggit farm, near Caslalia, Ohio.

Feet. Inches.

Earth ............................................................... 30

Limestone............................................................ 7

Limestone and gypsum interstratified.................................. 6

Gypsum............................................................. 3 6

Limestone and gypsum interstratified.................................. 4

Gray plaster ......................................................... 9

Gypsum............................................................. 3 10

Limestone ........................................................... 4

Gypsum.............................................................s 6 4

Limestone............................................................ 1

Gypsuni...._.............__.......--.._..........-................._ 3 2

Limestone -.--...._-----...........-.-...-.-...-..-.....-.......-.... 6

Total.......................................................... 83 10

At a depth of between 75 and 85 feet a heavv flow of water was 

encountered, which filled the drill hole to within 6 or 8 feet of the top.

A hole drilled for the Castalia Portland Cement Company about 1 

mile southeast of the one above described, and on slightly lower 

ground, gave the following section:

Section near Caslalia, Ohio.

Feet. Inches. 

Earth ............................................................... 46 6

Gray limestone....................................................... 19

Water in large amount came in at the bottom. The approximate 

location of this drill hole is shown on the accompanying map (PI. IX), 

and is numbered 1. A hole drilled in the flat north of the deposit 

(numbered 2 on the map) gave practically no gypsum. A hole a short 

distance to the east (numbered 3 on the map) gave but little gypsum. 

Drill records apparently indicate a local ridge or roll of gypsum, 

which is believed to lie in a somewhat semicircular area. On the 

north side of the bay the drill record at locality marked 4 on the map 

was as follows:

Section on north side of SandusJcy Bay, near Port Clinton, Ohio.

Feet.

Earth ..................................................................... 42

Limestone and gray plaster.................................................. 16
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. X

A. VIEW OF SOUTH SIDE OF FLETCH ERVILLE GYPSUM QUARRY.

B. VIEW OF NORTH SIDE OF FLETCH ERV I LLE GYPSUM QUARRY.
PEPPEL.] OHIO. 41

The terra " gray plaster" in these drill records signifies a mixture 

of gypsum and limestone, the masses and nodules of gypsum varying 

from those of small size up to that of a large bowlder. Between Port 

Clinton and the shore of the bay no workable gypsum has been found.

One and one-half miles southeast of Port Clinton gypsum is found 

on what is called the Lutzinger farm, where five holes have been drilled. 

One of the drill records is as follows:"

Drill record on Lutzinger farm, near Port Clinton, Ohio.

Feet. Inches. 

Earth .......... ^...i................................................ 30

Gypsum ............................................................. .. 18

Rock................................................................ 10

Gypsum.............................................................. 4

Rock................................................................ 8

Gypsum..........'................................................... 3

Rock................................................................ 6

Gypsum............................................................. 4

Rock................................................................ 2 10

Gypsum............................................................. 5

Eight holes have been drilled on what is known as the Charles Hehr 

farm. The record of one them is as follows:

Drill record on Charles Hehrfarm, near Port Clinton, Ohio.

Feet. Inches. 

Earth ............................................................... 19

Rock....................................:........... ...... .......... .. 18

Gypsum...................................................I......... 6 2

Rock.......................................I........................ 3 8

Gypsum............................................................. 2 7

Rock............................................................... 2

Five holes showing gypsum have been drilled on the Joseph Fletcher 

place, which is the site of the Fletcherville plant. The record of one 

of the holes is as follows:

Drill record at Fletcherville plant, near Port Clinton, Ohio.

0 ( Feet. Inches. 

Earth .......................................;..........'............. 14

Rock.................................................................. 18

Gypsum............................................................. 10

Rock............................................................... 3

Gypsum............................................................. 6

Between this place and the Forrester shaft, which is next described, 

some gypsum was found in a hole near the line of the Smitherbeck 

farm, but is not considered sufficient to work. It was reported to 

have a thickness of 3 feet 2 inches.

"This and the following sections are taken from, the driller's record; in every case the "rock" is 

probably limestone.
42 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

The record of the Forrester shaft on the Smitherbeck farm is as 

follows:

Drill record at Forrester shaft on Smitherbeck farm, near Port Clinton, Ohio.

Feet. Inches. 

Earth ............................................................... 17

Gypsum (bowlder)................................................... 2

Rock................................................................ .. 5

Gypsum............................................................. .. 10

Rock.......................................................... .... 2

G ypsum............................................................. .. . 7

Rock................................................................. 3 7

Gypsum............................................................. 1 8

Rock................................................................ 2 4

Gray plaster ......................................................... 7

Rock..................:............................................... 4

Gypsum............................................................. 4

Rock.................................................................. 10

Gypsum ...................................... ....................... 1 6

Rock.................................................................. 10

Gypsum............................................................. 4

The following is a record of the hole on the McDonald farm:

Drill record on McDonald farm, near Port Clinton, Ohio.

Feet. Inches. 

Earth ............................................................... 14

Rock.............. 1.................................................. 6

Gypsum............................................................. .. 20

Rock................................................................ 1 8

Gypsum .....................I....................................... 6

Rock................................................................ 1 9

Gypsum..................;.......................................... 2 6

Rock................................................................ 5

On the second farm, known as the Fletcher farm, a drill hole gave 

the following record:

Drill record on Fletcher farm, near Port Clinton, Ohio.

Feet.

Earth ..................................................................... 17

Rock............. .^....................................................... 8

Gypsum........._....:......_................«............................. 6

Rock.................................................'..................... 4

Gypsum................................................................... 3

To the east the gypsum deposits, according to the information thus 

far available, are relatively unimportant. There is evidently a continuous ridge of gypsum extending to the northeast, as shown by the 

records of drill holes on the Payne farm, one of which is as follows:

Drill record on Payne farm, near Port Clinton, Ohio.

Feet. Inches.

Earfti ............................................................... 28

Rock................................................................ 5 6

Gypsum............................................................. 1

Rock................................................................ 2 5

Gypsum............................................................. 4 3

Rock................................................................ 1
U. S. GFOLOGICAL SURVEY

A. EXPOSURE AT NORTH END OF MARSH & CO.'S QUARRY,

B, EXPOSURE OF GYPSUM IN OLD QUARRY OF MARSH & CO,
PEPPEL.] OHIO. 43

A large amount of gypsum has been taken from the Lockwood 

farm, near the shore of the bay. The deposits on this place have 

been nearly worked out. A short distance to the north of it is the 

quarry and shaft of Marsh & Co. A drill hole just northeast of the 

of the mill gave the following record:

Drill record near shaft of Marsh & Co., near Port Clinton, Ohio.

' Feet. Inches.

Earth ............................................................... 18

Bock................................................................. 1

Gypsum ............................................................. 6 6

Eock................................................................ 1

Gypsum.............................................................. 5

Eock....................................... ......................... 7

Gypsum............................................................. 4

Eock.........:............................................--.-.....- 4

Gypsum............................................................. 5

Kock............................................................... 3

Gypsum............................................................. 2

Rock................................................................ 10

Gypsum............................................................. 3

Eock................................................................ 2

Gypsum............................................................. 3

Eock.....................--.-------...--.-.---.-..--..-.-...-...--. 5

Gypsum......................... P................................... 10

Eock.........................................-.......-............:. 2

The gypsum at the lower levels is somewhat better in character, 

being clearer and containing some masses which are transparent. 

Three-fourths of a mile northeast of the last-mentioned place, at Gypsum station, there is a 4-foot bed of gypsum overlain by 60 feet of 

earth rock. A little north of the station, on the Miller place, there 

is a bed of gypsum between 3 and 4 feet thick, lying at a depth of 

72 feet. The upper and heavier beds apparently were not present 

at this locality.

The variable thickness of the limestone and gypsum beds is well 

illustrated by a comparison of the sections above described. It is 

also clearly shown by two sections given below, which were taken 

about 225 yards distant from each other. No. 1 is on the north side 

of the quarry and No. 2 on the south side.

Sections near Gypsum station, Ohio.

Soil and clay . . ......................

No. 1.

Feet. Inches. 

18 .....

1 .....

6 6

1 .....

5 .....

7 .....

4

No.

Feet. 

8

10

2

6 to 6

3

2.

Inches.

...... (shaly)

1 to 6

6

6 to 12
44 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

The three benches of gypsum given in section No. 2 are shown in 

the accompanying illustration (PI. XI, .7?), which is a view of a small 

portion of the quarry just west of the mine entrance. PL XI, A, shows 

the north end and east side of the same quarry.

It has already been suggested that the gypsum occurs in waves or 

rolls. These areas correspond to some degree with the surface of the 

ground, since as a rule only the high ground is found to be productive. 

However, in some cases the gypsum extends into the low ground. 

The general trend of the rolls is from northeast to southwest.

Prof. Edward Orton a gives the following section:

Feet. 

Drift clays, level of bay, 8 feet below surface....................... '. ...... 12-14

No. 1. Gray rock carrying land plaster ................................... 5

Blue shale........................................................ $

No. 2. Bowlder bed carrying gypsum in separate masses, embedded in shaly

limestones...................................................... 5

No. 3. Main plaster bed ................................................. 7

Gray limestone in thin courses .................................... 1

No. 4. Lowest plaster bed, variable....................................... 3-5

Mixed limestone and plaster bottom of quarry. Water enters here in

quantity.

The beds are not even and horizontal, but are^ found in waves or rolls, the summits 

of which rise 5 to 8 feet above the general level. Sections like the one here given will 

yield 50,000 tons of plaster to the acre.

The bed marked No. 1 in the section is a mixed deposit of shale and plaster that 

has hitherto been rejected, but which has recently been found fully available for 

grinding into a dark-colored land plaster. It has been lost by erosion in much of the 

territory already worked, and is not commonly counted among the valuable resources 

,of the quarries.

No. 2 is one of the most interesting divisions of the section. Scattered through the 

calcareous shales there are balls of gypsum, concretionary in form and probably in 

character, varying in diameter from 6 to 24 inches. For a long while it was thought 

that they were of inferior value, and they were ground into land-plaster, but recently 

it has been found that the purest product of the quarries can be derived from these 

same plaster balls. The gypsum yielded by them when they have been carefully 

freed from their shaly envelopes, proves to be of the whitest and purest sort, such as is 

used as terra alba.

GEOLOGIC RELATIONS.

The gypsum deposits of Ohio occur in what is known as the Rondout 

(Wateiiime) formation of the Silurian system, and lie within 150 to 250 

feet from the top of it. The rock overlying the gypsum and interstratified with it shows distinctly the lithologic characteristics of this 

formation. The conditions under which the gypsum was deposited 

were not favorable to life, and, as might be expected, there is no conclusive evidence as to the age of the beds available from fossils. It is 

impossible to trace the beds by means of exposures or sections, or to 

determine their relation to the formations below. However, 10 miles 

to the east the Onondaga (Corniferous) is recognized, and 26 miles to 

the west the lower beds of the Rondout waterlime are exposed.

a Geol. Survey Ohio, vol. 6, p. 698,
GYPSUM DEPOSITS IN MICHIGAN. 

By G. P. GRIMSLEY.

CHARACTER AND EXTENT.

The gypsum in Michigan is of the massive rock variety and occurs 

in heavy ledges. It is of high degree of purity. The deposits of 

economic importance are found in two portions of the State, though 

there is possibly a third area, as yet undeveloped. The two important 

areas are Grand Rapids and vicinity, on the western border of the 

Lower Peninsula, and Alabaster, on the eastern border, on Saginaw 

Bay. The third locality, where very little is known concerning the 

value of the deposits, is near St. Ignace, on the Upper Peninsula, and 

perhaps some of the northern islands of the Beaver Island group, 

where it would have to be mined.

The mills on the western border of the State are located in the valley of Grand River just below the rapids. The gypsum south of the 

river is found near Plaster Creek, and its outcrops in this creek have 

been traced for a distance of a mile from the Grandville road, north 

to the river. The bottom of the gypsum rock is about 10 feet above 

the river. North of the river the mines enter the hill at the level of 

the river plain, but on a downward incline from the level of the ground 

at the mills, and these mines are locally spoken of as caves. 

 In the city and northward, beyond the city limits, gypsum is found in 

wells at varying depths, but it appears to be absent in the wells to 

the east of the gravel ridges which pass through the town. Gypsum 

is also found in the deep wells to the west of the city.

The valley of Grand River widens to the south, near Grandville, and 

the drainage of the south is through Buck Creek. The quarries are 

located about 1 mile south of the river, and not far above its level, so 

that water is very troublesome and must be pumped.

The Alabaster quarry is located about three-fourths of a mile from 

Saginaw Bay, in the eastern part of the State. The bottom of the 

quarry is 15 or 20 feet above the water level. The gravel beach 

extends back a few hundred yards, beyond which the land is almost 

level for a long distance inland, and is more or less marshy. The 

gypsum is found at a number of places to the south of Alabaster, 

along the bay, and can be seen extending out from the shore under 

the water.

. Bull, 223 04 4 45
46 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223. 

ECONOMIC DEVELOPMENT.

In 1838 Dr. Douglass Houghton called public attention to the gypsum 

deposits in his first State report, and wrote that the gypsum in Kent 

County "can not fail to prove a subject of much value to the agricultural interests of this and adjoining parts of the State," a prediction which 

becam e a reality nearly thirty-five years later. In 1841 the first gypsum 

mill was erected, and was located on Plaster Creek, near the Grandville road. The mill was equipped with one run of millstones operated 

by water power, and the plaster was calcined in a 2-barrel caldron 

kettle. The mill manufactured land plaster mainly, and 10 years after 

the work was started, they made 60 tons of land plaster daily. In 

1849 the first mill north of the river was erected. It is still in operation. 

A second mill was erected in 1869. At the present time there is one 

mill in operation south of the river and one idle mill. These are four 

mills now in use north of the river.

At Grandville two mills were erected in 1872 and a third in 1875. 

The last is still in operation, while the others are idle.

The Alabaster mill is the only one in the eastern part of the State, 

and is located at the town of Alabaster in losco County. The quarry 

was opened and mill erected in 1862, and has been in operation almost 

continually since that time. Much rock is shipped from this quarry 

to other mills in Chicago and to Ohio.

DESCRIPTIONS OF LOCALITIES.

The original quarry of the Plaster Creek area south of the river, 

near Grand Rapids, is now filled with water. In the new quany the 

gypsum is found in two strata; the upper is 6 feet thick, and is separated by a foot or less of shale from the lower 12-foot ledge. The 

whole is covered by 12 to 15 feet of shale. The gravel cover is not 

thick. The upper 6-foot ledge is very irregular in its distribution, 

and runs out to the east and west within the quarry. On the north 

side of the quarry both layers of gypsum have disappeared over 

an area 100 feet wide and extending to the north. The gypsum 

at the side of this space shows the effects of water in its irregular surface. The main working is on the 12-foot ledge. The lower 2^- feet 

of this ledge is a red gypsum rock with red cone-in-cone gypsum 

called by the quarry men "pencil rock." The bottom rock is a hard 

blue limestone, called the flint rock.

North of the river the mines have been opened b}^ both drifts and a 

vertical shaft. The underground workings are on a double-entry system. The gypsum is worked on the drift and bench system, with no 

undercutting, and the roof gypsum is supported by heavy timbering. 

A geologic section at these mines shows practically the same series of
GKIMSMSY.] MICHIGAN. 47

gypsum and shales as south of the river, but the upper 6-foot ledge is 

more constant and is left for the roof of the mine.

In the Grandville quariy the gypsum stratum is 11 feet thick, covered by a foot of dark shale, over which is 20 feet of gravel. The 

floor of the quarry is a hard limestone 4 feet thick, and below it is a 

stratum of gypsum 14 feet thick, not worked. A shaft 32 feet deep has 

now been completed near the mill, and the quarry is to be abandoned.

The Alabaster quarry is the largest gypsum quarry in the State and 

probably in the United States. The gypsum face is 16 to 22-feet high, 

covered by 5 to 16 feet of tough bowlder clay, which is removed by 

steam shovel.

GEOLOGIC RELATIONS.

The interior coal basin.of Michigan is almost entirety surrounded by 

a border of Lower Carboniferous rocks, known as the Grand Rapids

formation, Avliich in age probably corresponds to the St. Louis, Chester, 

and Augusta formations of the Mississippian. This formation is divided 

in Michigan into the upper Grand Rapids and the lower Grand Rapids. 

The latter division was called by Winchell the Michigan salt group, 

but as it is without salt, it has been called by Lane the Michigan group.

The gypsum deposits at Grand Rapids and Alabaster are found in 

the lower Grand Rapids series. The thickness of this group is stated 

by Romingerto be 184 feet, and it is underlain by the Napoleon group 

of shales and sandstones, 123 feet thick, which in turn rest on the 

sandstones of the lower Marshall group.

The deposits near St. Ignace are in the Salina or Monroe group of 

the Silurian.
GYPSUM DEPOSITS IN FLORIDA. 

By DAVID T. DAY.

A deposit of gypsum has been observed about 6 miles west of 

Panasoffkee, Fla. It occurs in a low-lying area of hummock land, 

known as Bear Island. Near the rnarsh which surrounds the so-called 

island the deposit is covered with cypress trees and, farther in, with 

rather unusually large palmetto trees and the usual mixture of live oak 

and magnolia, with occasional low spots where nothing but cypress will 

grow. In the southern and southwestern portion of this so-called 

island the gypsum reaches the surface, with no covering whatever 

except an inch or two of vegetal mold. By striking a hoe into this 

the gypsum may be dug up in a soft state like claj^, but it soon hardens 

on exposure to dry air. It is greenish while wet and turns white on 

drying. Where the gypsum is at the surface there are knolls from 

10 to 50 feet square and 3 to 6 feet higher than the adjoining land, 

but the gypsum is found 'almost everywhere by slight excavation. 

The deposit is probably gypsite, or secondary gypsum.

Two pits sunk through it have shown it to be 6£ feet thick in one 

place and 7 feet thick in the other, with the usual light Florida sand 

underneath. Mixed through it are bowlders of very impure limestone, with occasional hard, flinty ones. As a rule the topography 

of the country will admit of digging 6 or 8 feet through the gypsum 

without encountering any considerable amount of water, except in 

the wet season.

The quality of the gypsum is almost uniform in all the places from 

which specimens were taken. The quantity is evidently sufficient for 

a large supply. The mining should be extremely easy except for the 

considerable work of clearing off the heavy growth of timber, about 

half of which will be of some value. The only difficulty to be anticipated in the mining is the fact that the lumps of limestone would be 

encountered at irregular intervals; their character makes it evident 

that they are residual lumps from limestone which has been dissolved 

by the action of rain water, as in many other parts of the State. 

It is probable that the floor of the deposit will frequently be a bed of 

limestone, very irregular in its surface, so that it will be difficult to 

dig all the gypsum from it by cheap means. This, however, should 

be a slight objection only, on account of the apparently large amount 

of material available, which will probably permit it to be profitably 

mined, even though a large amount of the bed is- left in place, 

48
G-YPSUM DEPOSITS IN IOWA. 

By FRANK A. WILDER.

CHARACTER AND EXTENT.

The gypsum of Iowa, so far as known, is found in a single area of 

60 or 70 square miles around Fort Dodge, in Webster County, near 

the center of the State (see PL XII). Within this area it is practically 

confined to a single bed. It is crossed by Des Moines River, and its 

extent north and south is about 6 miles, as is well demonstrated by 

exposures along the river banks. Elsewhere it is heavily covered by 

glacial drift, but well drillings and prospect holes indicate an extent

from east to west of 10 or more miles. The bed is practical^ horizontal, and varies in thickness from 10 to 25 feet. At least 40 square 

miles may be regarded as available for economic purposes. Within 

this area there are spots where the gypsum has been removed by preGlacial erosion. For this reason careful prospecting should precede 

the choosing of a site for mill purposes. If the gypsum area be 

regarded as only 50 square miles in extent, certainly a moderate estimate, there remains twelve hundred times as much as has been removed 

since the beginning of the plaster industry in Iowa. The average 

thickness of the gypsum suitable for plaster is 10 feet, and the yield 

per acre of a bed of this thickness is 30,000 tons. The deposit seems 

to lie in a well-defined trough, and instead of thinning out gradually 

it abruptly gives place to Coal Measure shales. The mantle of drift 

that covers it everywhere, except along the Des Moines and its tributaries, is from 60 to 80 feet thick.

All of the Iowa gypsum, excep't the crystals of selenite that are 

commonly scattered through the Coal Measure shales, is regularly 

stratified in heavy layers which are rarely less than 6 inches thick, 

while they attain a maximum thickness of 2 feet.

With the exception of a feAV thin layers that are scattered through 

the overlying clay at certain points, one layer is differentiated fro.m 

another only by the slightest trace of clay, and all go to make up a 

single compact bed. To the unaided QJQ the gypsum appears compact 

and dense. The microscope shows that it consists of a mass of minute 

crystals in which twinning planes and other crystalline characteristics 

are well developed. Although the gypsum is nowhere fissile, and 

breaks without regard to lamination, it is beautifully laminated, the 

bands, which are usually half an inch thick, being alternately darkgreen and white. This characteristic renders it peculiarly fit for 

hardening, so that it may be used in imitation oj: marble. Analyses 

show that the upper layers are composed of remarkably pure calcium

49
50 GYPSUM DEPOSITS ITST THE UNITED STATES. [BULL.223.

sulphate. The lower layers show 2 per cent of impurities, and are 

not used in the manufacture of wall plaster.

Where the full thickness of the gypsum bed occurs the miners 

recognize the following divisions:

Division of gypsum bed in Iowa.

Feet.

5. Upper rock, suitable for plaster, varying in thickness on account of differences due to loss by pre-Glacial erosion................................ 3-12

4. Six-foot ledge, best of the plaster rock .................................. 6

3. Hard ledge, inferior for plaster ......................................... 4

2. Eighteen-inch ledge, not good for plaster................................ 1£

1. Bottom ledge, not good for plaster .......... ............................ 5

Though the gypsum is now well protected by the thick mantle of 

drift that overlies it, at one time it formed the surface rock and in 

consequence suffered considerable erosion and solution. Where the 

overlying drift is removed its surface everywhere appears deeply 

trenched and worn. At times it is wholly cut out, and records of 

drillings at points wholly surrounded by gypsum show only gravel.

FIG. 5. Section showing relations of gypsum on Soldier Creek, Iowa, a, St. Louis limestone; 

b, Coal Measures; c, gypsum; d, drift.

Where exposed along ravines the gypsum is decayed to a depth of 

3 or 4 inches. Wherever it has been exposed in ledges for a few 

years it is picturesquely grooved and fluted.

ECONOMIC DEVELOPMENT.

. The first gypsum mill in Webster Count}^ was erected in 1872 at the 

head of Twomile Creek, better known as "Gj^psum Hollow." It has 

recently been remodeled. In 1882 the lower mill in Gypsum Hollow was erected, and this was followed in 1885 by the Blandon mill. 

Shortly after the erection of the Blandon mill, the Duncombe mill was 

built at the mouth of Twomile Creek. Thus three mills stand to-day 

on Gypsum Hollow, through which Twomile Creek flows. In 1895 the 

Cardiff mill began operations. This was the first of the mills built on 

the prairie. On account of the thickness of the drift, stripping was 

impossible, and mining by means of a vertical shaft was begun. The 

success of this mill encouraged the erection of other mills on the 

prairie, and in 1899 the Crawford mill was completed, and in the 

spring of 1900 the Mineral City mill made its first shipments. Another 

mill was erected in August, 1901, in NW. £ of sec. 4 of Pleasant Valley 

Township. Drillings at that point show 40 feet of soil and red shale, 

and 17 to 22 feet of gypsum. The eight mills in operation at present
U.S.GEOLOGICAL SURVEY BULLETIN NO. 223 PL. XII

[IT]

Permian Area of Permian. CoaL

in which gypsum Moasures 

is kncnvri to occur

MAP OF PART OF WEBSTER COUNTY, IOWA

SHOWING GYP SUM -BEARING ARE A

I I BY FRANK A.W1LDER 1 5^ I 

I I Scalp I I 

StLouis ' -2__-J-- 4 3 1 .-? rrale8 G>psum

mines

Glacial drift 

not. shown

Gypsum mills
WILDER.] IOWA. 51

have a total capacity of 700 tons of stucco per day of ten hours. The 

location of all of the mills and mines is shown on the small geologic 

map of the region immediately about Fort Dodge (PI. XII).

Most of the calcined gypsum of Iowa is sold as wall plaster. Less 

than 5 per cent of the product is sold as land plaster. For some years 

the Iowa Paint Manufacturing Company has operated a mill at Fort 

Dodge, using finely-ground raw gypsum as a base for paint. The 

various colors are produced by the admixture of pigments.

GEOLOGIC RELATIONS.

Directly associated Avith the gypsum, and in perfect conformity with 

it, are often 20 or 30 feet of- red shales and thin sandstone layers, 

while below and apparently associated with the gypsum is a clay layer 

4 feet thick. These relationships, as well as the relation of the gypsum series to the formations above and below, are shown along Des 

Moines River, and Soldier, Twomile", and Lizard creeks. Away from 

these streams, wells and prospect holes furnish but imperfect data for 

determining either the extent of the gypsum area or its stratigraphic 

relationships.

The gypsum series lies directly on the St. Louis limestone or on the 

Coal Measure shales (see tig. 5). The surface of the St. Louis limestone was uneven when the Coal Measure shales were laid down on it, 

and ridges and mounds project many feet into the shales. It is probable that the limestone was at one time wholly covered by the shales, 

but erosion of the shales before the gypsum was deposited brought 

the limestone to the surface at a number of points. In this way the 

varying relationships of the gypsum as exposed on Soldier Creek are 

to be accounted for. At one point it rests on the limestone and at 

another only a hundred yards away on Coal Measure shales.

The following section at the mouth of Soldier Creek is typical for 

the gypsum and associated red shales and sandstones:

Section at mouth of Soldier Creek, Iowa.

Glacial drift ............................................................... 35

Sandstone, soft, friable ...................................................... 5

Red shales, argillaceous, with some thin sand layers.......................... 5

Sandstone, buff, .friable..................................................... 2

Shale, gray ..........................................."..................... 2

Shale and thin layer of gypsum ............................................. 7

Gypsum, massive, exposed ................................................. 11

The following section in the pit of the Fort Dodge Clay Works 

shows the relation between the red shales of the gypsum series and 

the Coal Measures:

Section in pit of Fort Dodge Clay Works. . p

3. Drift.................................................................... 35

2. Red, sandy shales, with thin layers of sandstone, gypsum series ............ 10

1. Gray Coal-Measure shales, separated from the red shales above by sharp lines 

'of unconformity; along this line there is a layer of gumbo 1 foot thick .... 30
52 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

On the west bank of Des Moines River opposite the Blandon mill 

the following section is shown:

Section on west bank of Des Moines River.

Feet. 

4. Drift, yellow, unleached, with many limestone pebbles .................... 85

3. Gypsum, badly weathered, exposed ...................................... 10

2. Limestone containing Coal-Measure fossils (the stone is argillaceous and like

the limestone which generally caps the Coal Measures in Webster County). 2 

1. Coal-Measure shales, poorly -exposed on account of hillside wash ........... 60

The following section is taken from an exposure on Twomile Creek 

in Gypsum Hollow:

Section on Twomile Greek.

Feet. 

5. Drift............................................. i...................... 30

4. Eed, sandy shale .............................'........................... 0-4

3. Gypsum, massive, in places moderately folded, in layers from 6 inches to 2 

feet, laminae averaging three-fourths of an inch, alternating in color, gray 

and white............................................................ 20

2. Clay, thickness undetermined ............................................

1. Shale and sandstone (passed through in drilling well at lower mill of the

plaster company)...................................................... 100

A study of the broader relations of the gypsum series of Iowa shows 

that it lies in a fairly well-defined trough, or basin, stretching across 

Webster County from northwest to southeast. It rests unconformably on the underlying strata, both of Mississippian or Pennsylvanian 

age. This unconformity is good ground for believing that if the series 

belongs to the Paleozoic era, it was formed near its. close, during the 

Permian. The Permian of Kansas, Indian Territory, Oklahoma, and 

Texas includes immense deposits of gypsum which are associated with 

clays so highly and characteristically colored as to be known as the

Red Beds. Although a careful search has been made for fossils in the 

Iowa area, neither the gypsum nor the deposits associated with it have 

yielded any fossils, so that the age can not be determined on paleontologic grounds. This might naturally be expected, since the Red Beds 

of the Permian farther southwest are nearly barren of fossils. In 

Kansas, however, there is no unconformity between the Permian 

and the underlying Coal Measures.

The striking resemblance that the Iowa gypsum series bears to the 

Permian only 300 miles farther west, makes probable the assumption 

that the gypsum series of Iowa is an outlier of the Permian of Kansas 

and Indian Territory. During the long interval before the drift which 

now protects it was deposited there was abundant opportunity for 

erosion to remove the Permian from the intervening territory. The 

gypsum that remains was doubtless protected by heavy beds of red 

shale, for had it been exposed long it would have yielded to the 

solvent and erosive action of water.
GYPSUM DEPOSITS IN KANSAS. 

By G. P. GRIMSLEY.

CHARACTER AND EXTENT.

The gypsum of Kansas consists of extensive beds of rock gypsum 

and a number of deposits of secondary gypsum, or gypsite. Some of 

the rock gypsum is suited to the manufacture of the tiner grades 

of plaster of Paris, and the gypsite is particularly adapted for wall 

and cement plasters. There is a sufficient quantity of the gypsite now 

known to permit extensive operations for a number of years. Certain of the deposits, however, have shown signs of exhaustion, and 

have been abandoned. It is probable that others will be discovered, 

as there is a demand for further development of the industry. The 

rock-gypsum beds are so vast in their proportions that only those 

which are favorably situated with respect to transportation facilities 

will probably be worked.

The area in which gypsum is found is an irregular belt extending 

northeast and southwest across the State (PL XIII). It is naturally 

divided into three districts, which, from the important centers of manufacture, may be named the northern or Blue Rapids area, in Marshall 

County; the central or Gypsum City area, in Dickinson and Saline 

counties, and the southern or Medicine Lodge area, in Barber and 

Comanche counties. A number of small areas have been developed 

between these, connecting more or less closely the three main areas. 

The gypsum is found at Manhattan and north of that city, though not 

worked. It is worked at Longford, in the southern part of Clay 

County, and is found near Manchester, in the northern part of Dickinson County. Gypsum is worked near Burns, and has in past years 

been worked near Peabody and Furley, and large deposits are known 

near Tampa. Farther south, in Sunnier County, a large mill has been 

operated at Mulvane, and gypsum has been quarried at Geucla Springs. 

These different localities show an almost continuous belt of gypsum 

across the State.

From an examination of a map of west-central United States with 

the gypsum deposits indicated thereon, it will be seen that if the 

northeast line of the Kansas deposits is extended it will strike the Fort 

Dodge area in Iowa, and if it is continued to the southwest it will strike 

the extensive deposits of Canadian River in -Oklahoma and Indian 

Territory and Texas.

53
54 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223. 

ECONOMIC DEVELOPMENT.

The secondary gypsum deposits were developed first in Kansas, 

where they were discovered in 1SY3, near Gypsum City. This first 

deposit was not worked for plaster until 1889, and was abandoned 

about 1893. For a number of years the darker color of plasters made 

from gypsum earth hindered their sale, as the whiter plaster from the 

rock made a more beautiful wall, and was regarded as stronger. With 

the construction of the ornamental structures at the World's Fair, in 

Chicago, this earthy gypsum plaster was found to be adapted to staff 

work, and large amounts were so used. Soon after this time the 

plasterers became interested in the plaster, and many have regarded it 

as better adapted for certain work than the rock plaster.

Four of the nine Kansas plaster mills are now using this secondaiy 

gypsum in the manufacture of wall plasters. This variety of gypsum 

is said to require less retarder than rock plaster.

The excellent transportation facilities make Kansas a good area for 

gypsum plaster manufacture, as there are four main lines of railroads 

reaching the gypsum fields. The Blue Rapids and central areas are 

especially well connected by railroads with the cities of Colorado, and 

with Kansas City and St. Louis. The largest area, near Medicine 

Lodge, is not reached by any trunk-line railroad, and this fact has 

hindered its development. There have only been two small mills 

erected in this field.

DESCRIPTIONS OF LOCALITIES.

The first deposits of gypsum worked within the State of Kansas 

were in the northern area. The first mill was erected at Blue Rapids 

in 1872. This mill was operated until 1889, and then abandoned. In 

1887 a frame mill of one-kettle capacity was built on the west side of 

the town, at what is known as the Fowler mine. The entry to the 

mine is 15 feet above the water level, though the gypsum bed rock 

is the bed rock of the river, which is 4 feet deep at this place. The 

entry runs east about 400 feet, and the gypsum dips west toward the 

river.

The gypsum occurs as a gray mottled rock with saccharoidal texture, breaking with irregular fracture. It is somewhat crystalline, 

showing fibers and plates. Near the upper part the tendency to ciystallization is seen in the dark, irregular plates which characterize that 

portion of the stratum. The top consists of a layer one-fourth to one 

and three-fourths inch of white selenite needles forming satin spar. 

These stand vertical, and they appear to be oriented with the dark 

plates below. A similar layer of satin spar is found on the lower surface of the gypsum. The rock is traversed by blue clay seams, which 

contain a small amount of carbonate of lime. These are neither large
U. 6. GEOLOGICAL SURVEY BULLETIN NO. 223 PL, XIII

LEGEND

RAWINS n J

r~^ ^

CLOUD , 

is j OSBORNE J MITCHELL"^.____| h i

L j_________.\_______ 

I !

. DOUGLAS OHSSOJf * 

-4 4- i

FINNEY JHODGEM

, CHASE 1 

__ __i^Peabody r-r ' '-u° Burns 

\L-H-ARVEY f £->-- 

HutSiinson | ) * X

| i ^ i I 

\ \ V I

____-Wl L - 

iv V 4^ -J ^ N K TX^^r 

i CKAWPOBD , 

:_|_-_.U_____,_

Scale

Q 10 20 30 40 50. 60 70 80 90 100 miles 

MAP SHOWING GYPSUM DEPOSITS AND THE APPROXIMATE LIMITS OF THE PERMIAN IN KANSAS.
GR1MSLEY.] KANSAS. 55

nor numorous enough to injure the rock for plaster, and in some parts 

of the stratum they are absent. On exposure to the air for some time, 

or when crushed, the rock becomes very soft and snow-white.

In this mine "cutters" or veins occur which contain masses of transparent selenite crystals grown together, varying in size from the very 

smallest to those several inches in length.

The Great Western mine is located on the side of a bluff 1 mile 

north of the town of Blue Kapids and about 50 feet above the level of 

the water in the river. It is 2i miles southeast of the Fowler mine. 

The entry runs east of north, and goes into the hill over 400 feet. 

The section of the mine and hill above, 

fig. 6, shows a gypsum bed 8i to 9 feet 

in thickness.

On the bank of the Little Blue, 2 

miles west of Blue Rapids, is located 

the Winter mine. The rock was formerly obtained by stripping, and a very 

considerable area was thus worked out; 

but as the cover became thicker back 

from the river, it was thought to be 

more economical to mine by running 

an entry into the hill. This entry is 

about 15 feet above the level of the 

water, and runs east about 1,000 feet 

into the hill. The double-entry system of mining is used, Avith rooms 16 

feet square. A geologic section at the 

mine shows a compact limestone floor 

on which rests 8 to 9 feet of gypsum. 

This is covered by about 10 feet of red 

and blue shales, and two limestones of 

2 and 3 feet thickness, separated by 11 feet of shales and shaly 

limestones.

In the northern part of the central or Gypsum City area, 6 miles 

southwest of Solomon, on the bank of Gypsum Creek, a mine was 

formerly worked. A section of the hill at the mine, represented in 

fig. 7, shows 40 feet of shales and gypsum. The mine entrance is 15 

feet above the water in the creek, and the stratum worked was 5 feet 

thick. The shales, with the intercalated gypsum layers, are folded 

and broken. The folds extend down into the mine, causing the shales 

of the roof to cut out the gypsum in many places. This fact caused the 

abandonment of the mine. The dip of the gypsum is north, toward 

the creek. The lower part of the heavier gypsum layer is very compact, and filled with crystals of yellowish-brown selenite, having the 

greater length in the direction of the vertical crystal axis. The crysBulC limestone, 2 ft. 6 in.

Shale, 50 ft.

Limestone, 2 ft. 0 in.

Shale, 20 ft.

Limestone, 2 ft. 1 in.

Keel anil blue shale, 8 ft.

Gypsum, 8ft. Oiu.

Limestone, 2 ft. 0 in.

10ft.

Shale.

8ft.

Limestone, 1 ft.

Shale. 7 ft.

Cottoiiwood limestone. 5 ft.

PIG. 6. Section at Great Western gypsum 

mine, Blue Kapids, Kans., showing relations of gypsum to Cotton wood limestone.
56 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

tals are laminated by a pronounced pinacoidal cleavage. The larger 

ones are about seven-eighths of an inch long and half an inch wide, and 

rock specimens from this portion of the stratum break with a conchoidal fracture. The upper part is white, less compact, contains no 

such crystals, and pieces break more irregularly.

At Hope, 20 miles southeast of Solomon, there are gypsum deposits 

which have been in operation since 1887. At first gypsum rock was 

quarried near the top of the hill, 1£ miles west of the town. The 

bed is 5 feet thick, and lies 10 feet below a buff, shaly limestone. 

The gypsum is white and compact in texture, except near the surface, 

where it is rendered granular and more or less colored as a result of 

weathering. The satin spar associated with it is of clear white color. 

In 1894 this quarry was abandoned, and at a point a quarter of a mile 

west of the quarry a shaft 80 feet in depth was sunk to a lower stratum 

of gypsum, which is nearly 14 feet thick. The rock is white, though 

much of it is traversed by wavy dark lines which lie close together, 

giving an appearance somewhat like granite or gneiss, so that the 

plaster made from it is called by the company'' granite cement plaster."

The lower part of the stratum is compact, and contains 

rounded crystals of selenite, 

with dark, mottled surfaces. 

It thus bears a close resemblance to the Solomon gypsum, already described, 

although the crystals are 

usually larger, averaging 

about 2 inches by 1 inch. A study of the levels and character of the 

rock indicates that the gypsum quarried below Solomon is the same as

that in the shaft near Hope.

South of Dillon an 18-foot stratum of gypsum rock is being worked. 

It is reached by a shaft 78 feet in depth. .

Important secondary deposits of gypsuin occur at a number of places 

in the central and southern areas. They supply the greater portion of 

the plaster manufactured in Kansas. The material is locally called 

"stucco," "gypsum dirt," "gypsite," and other similar names. It is 

a granular earth, found in low, swampy ground, dark colored in place, 

but on drying it assumes a light ash-gray color. It is soft and incoherent, so that it is readily shoveled into cars, and is ready for calcining 

with less labor and expense than is required in working the solid rock. 

The first deposit was discovered in the spring of 1873, near Gypsum 

City. It covers an area of 12 acres, and lies close to the surface, with 

little or no cover. The maximum thickness is 17 feet, with an average 

of 8 feet. The appearance of the deposit resembles very much a fine 

sand bed or loess formation, and there is a tendency to break into

Soil and gypsum, 4 ft. 

2 ft.

2ft. flin. 

Buff shale. 5 ft.

Gypsum, 2 ft. 

2ft.

Gypsum, 5 ft. 

Limestone, 3 ft. G in. 

Shale and limestone, 5 

Gypsuin, 3 ft.

FIG. 7. Section at Solomon gypsum mine, Kansas.
GRIMSLEY.] KANSAS. 57

smooth planes or joints. Strong springs break through the deposit on 

the east side. The top of the gypsum earth is 20 feet above the water 

in Gypsum Creek, a quarter of a mile to the west. In a well dug on 

the hill above the deposit, rock gypsum of good quality was struck 30 

feet down, or 20 feet below the top of the earth. No trace of gypsum 

was found in the hills above the gypsum earth.

The gypsite deposit near Dillon, 14 miles east of Gypsum City, is 

very similar to the one last described, and is at least 40 acres in extent. 

It lies in swampy ground near a small creek. Its greatest thickness is 

18 feet. It is covered to a slight depth with soil. Springs of water 

occur through this deposit and are veiy troublesome when the gypsite 

is worked. Gypsum rock outcrops a quarter of a mile away, at the 

same level. The gypsum earth was taken out by aid of the plow and 

scraper, and after drying a few days in the sun was loaded into cars 

and hauled to the mill, one-half mile north. The mill was taken clown 

a year ago and moved to Acme, Tex., and the deposit is no longer 

worked.

Another similar deposit is located 3£ miles southwest of Dillon in 

a low place near a small stream, and here again springs prove troublesome. The cover is 10 feet thick, and the deposit varies from 5 to 8 

feet. It is claimed that the deposit extends over 60 acres.

Four miles east of Longford, Clay County, and near a small creek, 

there is a gypsum-earth deposit which varies from 2 to 10 feet in 

thickness over an area of about 60 acres. Other gypsum-earth deposits 

are reported from this same region, and near Manchester.

Seven and one-half miles southwest of Burns, close to Davis Creek-, 

in Butler County, a gypsum-earth deposit is worked. This deposit 

averages 6 feet in thickness, and is whiter than the material in the 

other deposits in the State. It is covered by a thin layer of soil varying 

from 1 inch to 2 feet in thickness. Where Davis Creek cuts through 

the gypsum the deposit is.about 9 feet thick, and has a jointed structure, 

breaking out in large blocks. Thus far gypsum rock has not been 

found in the region above this gypsum-earth deposit, nor has it been 

reported in any of the wells in that vicinity.

Gypsum earth has been worked 2£ miles northeast of Mulvane, just 

across the Sedgwick County line. The material was 3 to 12 feet thick, 

and was worked for several years. The deposit showed signs of giving 

out, so the mill was removed.

This southern gypsum area is the largest in" Kansas, and with its 

continuation in Oklahoma and Texas forms the largest gypsum, area 

in the United States. The rock extends from near the town of Medicine Lodge westward through Barber and Couianche counties, southward into Oklahoma, and passes under the Tertiary gravels to the 

north.

The gypsum of the Medicine Lodge area is mainly rock gypsum, is
58 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

Stratified gypsum, 25 ft.

Ked shale, 80 ft.

Green gypsum, 3 ft.

Red shale. 65 ft.

Red sandstone, 10 ft.

white in color, and. in the lower portion of the stratum is very 

compact. The satin spar which is found throughout the Red Beds 

below the gypsum is in the form of wavy plates, with perpendicular 

needles. It is variable in character; some of it is soft and readily 

crumbles, while other portions are compact and glassy in appearance.

The gypsum is first seen 6 miles southwest of Medicine Lodge, in an isolated 

range of hills 3 miles long, separated 

by a narrow valley from a second hill 1 

mile in length. The valleys of East and 

West Cedar creeks, 2 miles wide, separate these hills from the next series, in 

which the gypsum plateau is continuous 

to the west.

In the eastern part of Comanche 

County, on Cave Creek, a second g3rpsum layer, 15 feet thick, is found 15 feet 

above the Medicine Lodge layer. This 

upper layer was called the Shinier gypsum by Cragin. It appears to be a local 

deposit.

Looking west from the town of Medicine Lodge one can see in the distance a 

range of eroded hills with sloping sides 

and level tops. These hills extend in a 

north-south direction, and are called the 

Gypsum Hills. The sides are composed 

of the red shales and clays of the Red 

Beds. The cap rock is a ledge of -gypsum, which has protected to a considerable extent the underlying soft strata. 

A section of the hills at Medicine Lodge 

is shown in fig. 8. The gypsum layer 

varies from 3 to 20 feet in thickness, 

depending upon the amount of erosion. 

The red clays and shales below the gypsum contain an interlacing network of 

selenite and satin-spar laj^ers of variable 

thickness. This material has been dissolved out of the solid stratum and carried downward through the 

agency of circulating water and redeposited.

In the western part of Barber and the eastern part of Comanche 

counties the solvent effects of water on the gypsum are well shown, 

for there are found natural bridges and underground watercourses,

Red shale, 100 ft.

}, Medicine River.

IG. 8. Section of Medicine Lodge Hills, 

7 miles southwest of Medicine Lodge, 

Kans.
GRIMSLEY.] KANSAS. . 59

GEOLOGIC RELATIONS.

In the northern or Blue Rapids area the gypsum, as is shown by 

the section, fig. 6, is 30 feet above .the Cottonwood limestone, which 

has been taken by Prosser and others as the dividing line between the 

Coal Measures and the Permian. This places the northern gj'psuni 

in the basal portion of the Permian. The gypsum deposits near Hope, 

Solomon, and Dillon are somewhat higher stratigraphically and in the 

division of the Permian known as the Marion. The Medicine Lodge 

beds are the highest in the series. The gypsum at Geuda Springs 

occupies an intermediate position between the Medicine Lodge horizon 

and that which is interbedded with the Permian limestones, and is in 

the blue shales known as the Wellington shales, which farther south, 

in Oklahoma, have as their equivalents red shales and sandstone.

Bull. 223 04- 5
GYPSUM DEPOSITS IN OKLAHOMA. 

By CHARLES N. GOULD.

CHARACTER AND EXTENT.

Oklahoma occupies a central position in the belt of country which 

carries extensive gypsum deposits all the way from the northern part of 

Kansas into central Texas (see PL XIV). Within its borders the number and thickness of the beds appear to be greater than to the north 

and south. The amount of gypsum appears to be inexhaustible. 

With perhaps two exceptions, each of the western counties contains 

enough material to supply the United States for an indefinite length 

of time, and there are in addition considerable deposits in the eastern 

part of the Territory. For convenience of discussion the gypsum in 

Oklahoma may be considered as occurring in four regions: (1) The Kay 

County region; (2) the main line of gypsum hills, extending from 

Canadian County northwest through Kingfisher, Blaine, Woods, and 

Woodward counties to the Kansas line; (3) the second gypsum hills, 

parallel with the main gypsum hills, and from 50 to YO miles farther 

southwest, which extend from the Keechi Hills, in southeastern Caddo 

County, northwestward through Washita, Custer, Dewey, and Day 

counties; and (4) the Greer County region, occupying the greater 

part of western Greer County and the extreme southeastern corner of 

Roger Mills County.

The deposits in Kay County consist of gypsum dirt, or gypsite. In 

the other three regions rock gypsum predominates, although there 

are numerous localities where gypsum dirt occurs in workable bodies. 

The amount of rock gypsum in Oklahoma has been approximately 

estimated by computing the area and the thickness of the exposed 

beds and reducing the amount to tons. The quantity in each county 

is set forth in the following table:

Estimated amount of gypsum in Oklahoma.

	Tons. 

Canadian County....... ...............:....................... 50,000, 000

Kingfisher County ............................................. 50, 000,000

Blaine County ................................................. 2, 500,000, 000

Woods County................................................. 14, 000, 000, 000

Woodward County ............................................. 24, 000, 000, 000

Comanche County.............................................. 200, 000, 000

Caddo County ................................................. 3, 000, 000, 000

Washita County................................................ 20, 000, 000, COO

Custer County ...........................:..................... 6, 000, 000, 000

Dewey County ................................................. 1, 000, 000, 000

Day County.................................................... ' 500, 000, 000

Roger Mills County ............................................ 1, 000, 000, 000

Greer County .................................................. 53, 000, 000, 000

Total.................................................... 125, 300, 000, 000

60
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. XIV

MAP SHOWING GYPSUM DEPOSITS IN OKLAHOMA.
OOULD.] OKLAHOMA. 61

The total of 125,300,000,000 tons, however, fails to convey an idea 

of the extent of the gypsum resources, because the amount is so enormous. In the above estimate the gypsum in Kay County, and other 

gypsum-earth deposits, are not included, because they occur in local 

and irregular areas.

ECONOMIC DEVELOPMENT.

Notwithstanding the fact that gypsum is widely distributed in Oklahoma, the amount manufactured in the Territory is relatively small. 

This is due in large part to the fact that it is a newly settled country, 

in which railroads have but recentl}7 been constructed. Moreover, the 

cost of transportation is important, even where railroad facilities ar.e 

good. The gypsum industry has had an extensive development in 

Kansas, to the north, and the Texas deposits have been worked to 

some extent. Oklahoma has had to compete with these neighboringStates. Another matter scarcely less important than that of transportation is the one of fuel, but, fortunately, the Indian Territory coal 

fields are relatively near at hand.

In addition to the matter of transportation of the finished product, 

the handling-of the raw material and the delivery of it-at the mills 

has to be considered if operations are carried on economically. There 

are now a number of locations suitable for gypsum mills, and the 

building of branch railways promises access to more of the deposits.

At the present time there are but four mills in operation. One is 

located at Peckham, in Kay County, one at Okarche, in Canadian 

County, and one at Watonga and one at Ferguson, in Blaine County. 

The mill at Peckham is situated li miles southeast of the town, and 

was erected in the summer of 1899. The raw material is gypsite, or 

gypsum dirt, which is hauled to the mill in wagons. The mill at 

Okarche has been in operation for a number of years. In the beginning of operations raw material was obtained near at hand, but, as 

is frequently the case, the deposits which were first worked have been 

exhausted, so that it is necessary to haul the gypsum earth a distance 

of nearty 2 miles. The mill at Watonga is 3 miles distant from the 

gypsum deposits, but the mill and quarry are both located on a railroad, which affords transportation facilities. The deposit which is 

worked at Ferguson is on the head of Salt .Creek, 4 miles west of the 

town, and consists of rock gypsum exposed in heavy ledges. It is 

quarried and transported by a gravity tram a distance of 500 feet to 

the mill.

There has recently been some development of the deposits at 

Cement, in the Keechi Hills, in Caddo County. Gypsum dirt is 

shipped from this place to the mill at Marlow, Ind. T., the deposits 

at Marlow having been exhausted._- It is probable that the industry 

will receive further extension in the near future.
62 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

A point which is of interest in connection with the working of the 

Oklahoma gypsum is the fact that springs of good water can often be 

found in the vicinity of the deposits. These springs are located in the 

sand hills or surficial deposits, and the water from them is either 

piped to the mills or raised into reservoirs. The supply is usualty 

adequate for steam and domestic use.

DESCRIPTION OF LOCALITIES.

Kay County. The gypsum deposits in Kay County are found in the 

valleys of Duck, Bois d'Arc, Bitter, and other creeks that flow southward into the South Fork in the vicinity of Newkirk and Blackwell. 

.They do not appear to be very extensive, although they have furnished sufficient material for the operation of the plant at Peckham.

The region is slightly rolling, and the 

valleys of the creeks are shallow. The 

rocks in this region consist of gray 

Red gypsirerous clay, 27 ft. and bluish clays and shales, with a few 

ledges of soft, impure limestone. The 

deposits have about the same general 

relations as the gypsite deposits in 

southern Kansas, and, like them, are of 

secondary origin. Gypsum is not uncommon in the rocks of this region, 

although no extensive beds are known. 

The gypsum dirt has probably been 

deposited by surface evaporation of 

waters which contained it in solution. 

The deposits which have thus far been 

worked are in places 10 feet in thickness and cover several. acres. It is 

not known whether other workable 

deposits of the same relative position 

as those in Kay County will be found farther south in the eastern part 

of Oklahoma. There are many localities, however, at which farmers 

dig small amounts of gypsum dirt and manufacture it into plaster for 

their own use.

Main line of gypsum hills. The first ledges of rock gypsum encountered in crossing Oklahoma from east to west are along the main 

line of gypsum hills, which extend uninterruptedly from the vicinity 

of Elreno, Okla., northwestward beyond Medicine Lodge, Kans., 

the best development being along the south side -of Cimarron River, 

in Woods and Woodward counties. These hills contain two, and 

sometimes three, ledges of massive white rock gypsum, interstratified 

with beds of red clay shale. The cla}7" weathers more rapidly than the 

gypsum, and the protecting cap of gypsum rock gives rise to an escarpMassive white gypsum, the

Shimer, 15 ft. 

Soft gray sandy dolomite,

1ft.

Massive white gypsum, the 

Medicine Lodge, 17 ft.

Eed gypslferous clay with 

green bands of selenlte,

25 ft.

Pinkish mottled gypsum, 

irregularly stratified, the 

Fergnson, 6 ft.

Red gypsiferous clay with 

thin green and white selenito bands and layers, 86 ft.

FIG. 9. Section near the gypsum mill, Ferguson, Blaine County, Okla.
GOTJLD.] OKLAHOMA. 63

merit. The numerous isolated hills which lie to the east of the 

escarpment are remnants of it which have been cut off by erosion. 

In addition to the gypsum there are some thin ledges of dolomite 

which act in a manner similar to the gypsum in producing the characteristic topographic forms of this region. The disintegration of the 

shales below the gypsum cap causes huge blocks to break off and fall 

downthe slopes into the canyons, so that quantities of these bowlders 

are strewn on the surface.

Viewed from the east, the gypsum hills appear as a wall crowned 

with a white ledge. The sky line, however, is not continuous, since 

numerous breaks occur where the^psum has been eroded. Where the 

escarpment is broken and the country is dissected by streams there are 

flat-topped buttes or mesas. Not infrequently bold points stand out 

at short distances east of the main hills. Some of the more conspicuous 

of these outliers have received distinct 

names, such as Glass Mountain (see 

PL XV, A), Wildcat Buttes, Mount 

Hernan, and Cedar Hill. The main 

range of hills has likewise received 

local designations, such as Stony Hills, 

in Blaine County, east of Watonga, and 

Chautauqua Mountains, for the hills 

in Blaine and Woods counties. The 

name Marcy Range has been proposed 

for the entire series of hills, but it is 

doubtful whether it will ever replace 

the cowboy name of '' Gyp Hills." The 

height of the escarpment varies from 

50 to 250 feet, according to its proximity to the main streams of the region.

The three conspicuous gypsum beds in this line of hills have been 

given names. The lower is the Ferguson gypsum. It extends from 

Canadian County northward into Woods County, where it disappears. 

The bed above it is known as the Medicine Lodge gypsum. It extends 

uninterruptedly from Canadian County to the north of Medicine Lodge, 

Kans., for which place it was named. The third gypsum ledge is 

known as the Shimer gypsuni. It has practically the same extent as 

the Medicine Lodge, but is not quite so thick.

Figs. 9 and 10 show the relations of these beds at two localities in 

the line of hills.

Second gypsum hills. To the west of the first gypsum hills, and at 

a higher level geologically, there is a line of outcrop of gypsum beds 

which is here described as the "second gypsum hills." These hills 

differ in being less well defined as topographic features. This is largely 

due to the fact that the gypsum beds are not uniform in character and 

do not continue for long distances. Sections made at various places

Keel clay to top of bluff, 15 ft.

Massive white gypsum, the 

Shinier, 15 ft.

Bed clay, 10 ft.

Massive white gypsum, the 

Medicine Lodge, 24 It.

lied clay with bands ot sclcnite and gypsuni concretions from the level of the 

plain, 80i:t.

PIG. 10. Section southeast of salt plain in 

Woodward County, Okla.
64 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

show little agreement in the alternation of gypsum, clay, and sandstone 

beds. At some places nearly the entire interval is occupied by gypsum, while at others it is absent or is represented by thin and irregular 

deposits. The gypsum appears usually in bluffs and canyon walls, or

capping mounds or the summits 

of rounded hills; The width of 

the area in which gypsum is found 

varies from a few miles to as 

man}r as 30 miles in some places. 

The southernmost portion of 

this line of deposits is found in 

the northern part of Comanche 

County, south of the Keechi

situated prj nci _

Massive white gypsum, 18 ft.

Sandstone and red clay, 28 ft.

Massive white gypsum, 8 ft.

Soft, red gypsiferous sandstone, 75 ft.

pally in Caddo County. The 

ledges outcrop in rounded knobs 

in the prairie region. In Caddo

FiG.ll.-Secti0nofa^5omilessoutheastofCloud Q^y SQme Qf th0m attam R

thickness of 50 feet, but usually

they are not over 15 feet thick. There are extensive deposits of gypsum dirt at this locality, which have already been developed to a 

limited extent.

Northwest of the Keechi Hills, in Caddo Count}r, there is a smaller 

area in which the ledges of g}^psum form the cap of a line of bluffs

Rough weathered sandy dolomite capping the high hill, 3 ft. 

Red and green gypsiferous clay shale. 2i ft.

Massive white gypsum, 18 ft.

Rod and green shale, 6 ft.

Massive white gypsum, 18 ft. *

Red and green clay shale, 15 ft.

Massive white gypsum, occasional ledge of sandstone. 25 ft.

Reddish and green shale, 24 ft.

Greenish gypsum and gypsiferous shale becoming hard locally, 5 ft.

Red and green gypsiferous clay shale from the base of the hill, 30 ft.

FIG. 12. Section of a bluff 3 miles south of Carter, Koger Mills County, Okla.

which continue for a considerable distance along the south side of 

Washita River.

In the western border of Caddo County the gypsum again appears, 

from which place it extends northwestward into Washita County,
U. S. GEOLOGICAL SURVEY 1ULLETIN NO. 223 PL. XV

A. GLASS MOUNTAIN, WOODS COUNTY, OKLA., CAPPED WITH MASSIVE GYPSUM.

B. ESCARPMENT CAPPED WITH GYPSUM LEDGES, RED RIVER VALLEY, GREER

COUNTY, OKLA.
GOULIX] OKLAHOMA. 65

where this line of hills may be said to culminate. The stratification 

is here very irregular. The section shown in fig. 11, taken 5 miles 

southeast of Cloud Chief, shows that the gypsum is in heavy beds. 

This section can not, however, be considered typical, since a short distance away a bed 50 feet in thickness Avas found, and from a well near 

Seger a bed 115 feet in thickness was reported, besides several thinner beds.

In Custer County the gypsum is widely distributed, certain of the 

beds being more than 60 feet in thickness, and there are often several 

ledges 10 or more feet in thickness found in the same hill.

In Dewey County there is practically but one stratum which is persistent. It occurs in 

the buttes and bluffs in 

the central and western 

part of the county and 

varies from 2 to 5 feet 

in thickness. It continues along the valley 

of the South Canadian, 

into the eastern portion 

of Day County.

Greer County region. The gypsum 

found in Greer County 

is believed to be the 

equivalent of the beds 

described as occurring 

in the second gypsum 

hills. Thus far it has 

been impossible, however, to definitely trace 

the connection satisf acHard rock (dolomite) forming the cap of the hill,:! ft 

Rod nncl blue clay, 12 ft.

Massive wliito gypsum, 8 ft.

Rod <;lny with ledges of gypsum, 24 ft.

Massive white gypsum, 12 ft.

Red and blue clay, 15 ft.

Red and blue soft shaly rock and gypsum, 5 ft.

lied and blue shaly clay, 27 ft. *

Bluish gypsiferous rock, 10 ft. 

Red and blue clay. 8 ft. ' Massive white gypsum. .3 ft.

Ked clay slope from Horse Branch. 100 ft.

FIG. 13. Section of a bluff on Salt Fork, 10 miles south of Mangum, Greer County, Okla. torily, and a comparison of the sections is an 

unsatisfactory method of correlation, because of the erratic nature of 

the beds in the second -gypsum hills. In Greer County the gypsum 

ledges are very regular, the individual beds being persistent for long 

distances. In this respect they are similar in appearance to those of 

the first line of gypsum hills. They are more numerous, however, 

since there are five which are well defined. The three upper ones are 

the thickest and most conspicuous. The lower two are not more than 

4 feet in thickness, and because of their position near the foot of the 

bluffs, are often concealed. The gypsum beds have been named as 

follows, from the base of the section up: Chaney, Kiser, Haystack, 

Cedartop, and Collingsworth.
66 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

The Chaney gypsum is well exposed along the south side of Elm

Creek, from Manguni, in Greer County, northwest of the Texas line.

It extends into Eoger Mills County, but is much changed in character,

frequently being simply a gypsiferous band in the red claj^.

The Kiser gypsum varies considerably in local sections. Usually it

is from 1 to 3 feet in thickness, and is best exposed in the western

portion of Greer County.

The Haystack gypsum is the heaviest of the ledges in this locality,

varying in thickness from 18 to 25 feet. It is conspicuous along

the bluffs on North Fork and Elm Fork.

The Cedartop bed is massive and 

from 18 to 20 feet in thickness. It 

is very regular in occurrence, and 

is found capping buttes and bluffs, 

especially along the North Fork, 

Haystack, and the Elm Fork.

The Col lings worth gypsum is not 

materially different from the two 

beds previously described. It varies from 18 to 20 feet in thickness, 

but inasmuch as it is the upper bed 

it does not always occur in the section, erosion having carried it a way. 

The occurrence of the gypsum 

ledges has given rise to broken 

topography where the streams have 

cut their canyons. Over considerable areas in the southern part of 

the count}7 , however, erosion has 

not exposed the beds, and the country is accordingly rather level. At 

such places the presence of the gypsum beneath is occasionally revealed 

\)y sink holes, which have resulted 

from its solution.

Quartermaster division, 300 ft.+

Greer division, 250ft.

Woodford division, 300 ft.

Blaine division. 7f> ft.

Norman division, 1,000 ft.+

GEOLOGIC RELATIONS.

FIG. 14. General section of the formations of 

Oklahoma. The gypsum deposits in Oklahoma are of Permian age. This is 

determined by the occurrence of vertebrate fossils in the Norman 

division, near Hardin and Orlando, at .horizons lower than the gypsum, and invertebrate fossils which have been found higher in the 

section at White Horse Springs. The stratigraphy of the region is 

difficult to determine, except where there are outcrops of persistent 

gypsum ledges and of some thin beds of dolomite. The other forma-
COULD.] OKLAHOMA. 67

tibns are essentially shales and sandstones, which have no distinctive 

lithologic characters and which are difficult to identify in the outcrops. 

In passing across the country from west to east certain changes in the 

character of the rocks are readily observed, but in establishing the 

section the recognizable horizons are, as has already been stated, the 

dolomites and gypsum. A general section is given in the accompanying figure (fig. 14), and the divisions proposed are indicated in it. Itwill readily be seen that there are two groups of gypsum beds those' 

in the Blaine division, found in the first line of gypsum hills, and the 

beds in the Grreer division, which occur in the second line of gypsum 

hills and the Greer County area. The lower beds extend northward 

into Kansas, past Medicine Lodge, to a point where they disappear 

under the overlapping Tertiaiy. Southward, in Texas, there are 

extenswe deposits, which may be the equivalent of the upper group, 

or possibly in that region the gypsum is at a higher horizon.
G-YPSUM DEPOSITS IN TEXAS. 

Ity BENJAMIN F. HILL.

CHARACTER AND EXTENT.

The occurrence in Texas of gypsum deposits of great extent has 

long been known through the reports of early exploring parties. 

Captain Marcy, in the report of his expedition along Red River in 

1852, mentions, the gypsum beds encountered in his journey and comments upon them as follows:

FIG. 15. Map of Texas showing location of areas containing principal deposits of rock gypsum.

I have traced the gypsum from the Canadian River in a southwest direction to. 

near the Rio Grande, New Mexico. It is .about 50 miles wide upon the Canadian, 

and is embraced between the ninety-ninth and one-hundredth meridians west longitude. Whenever I have met the gypsum I have observed all the varieties from the 

common form to pure selenite. I regard the gypsum belt as a very prominent and
HILL.J TEXAS. 69

striking feature of the geology of the country. From its uniformity and extent 1 do 

 w not think there is a more perfect and beautiful formation of the kind known. I 

^ have myself traced it about 350 miles, and it probably extends much farther.

While the whole of the deposit described by Captain Marcy is not 

in Texas, and it is now known that the formation is not continuous to 

the Rio Grande, the deposits are a portion of an interrupted belt which 

in Texas extends from Red River to the Colorado, and is found again 

to the west of the Pecos near the New Mexico line.

In the year 1855 the War Department sent out another expedition 

under the command of Capt. John Pope. Dr. George H. Sbumard 

performed the duties of both surgeon and geologist. His observations 

on the gypsum deposits of the region between the Pecos River and the 

Guadaloupe Mountains were published many years later in Geology 

I of Western Texas (Austin, 1886).

In the reports of the geological survey of Texas from 1889 to 1892 

there are many observations on the gypsum deposits, especially in the 

reports by A. F. Cummins. Quotations from his writings and the 

reports of other members of the survey are given later in this article. 

The gypsum deposits of Texas have never been adequately treated, 

and can not be until more detailed field work has been done. The 

information here presented is from the observations of the writer and 

the published reports above cited.

The class of deposits which has attracted most attention is the rock 

gypsum. The areas in which it occurs are shown in the accompanying map of Texas. Thus far no effort has been made to discover 

deposits of gypsite or gypsum earth. They no doubt occur associated with the rock gypsum at some localities and will be sought for" 

as the industry in Texas develops. A number of geologic formations 

contain more or less gypsum occurring as individual crystals or concretions. These can not be considered of commercial importance, but 

because they contain conspicuous amounts at certain localities menj tion is made of some of them in this report.

k ECONOMIC DEVELOPMENT.

!

' There are only two plants for the manufacture of gypsum products 

in Texas. They are at Acme, near Quanah, on the line of the Fort 

Worth and Denver City Railway, at the north border of the State. 

It would seem at first thought that with such enormous deposits other 

plants would have been established, but the matter of transportation

! is of so much importance and the position of the deposits with respect 

to railway lines is not favorable to their successful exploitation. No 

doubt with the building of additional railways the industry will-be 

established at other points. The line of the Orient Railroad passes 

through the gypsum belt in the northern part of the State, and when 

completed will undoubtedly make this resource more available.
70 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

Recently, with the construction of a better class of buildings, gypsum plaster has, come more into use. The climate of a large portion 

of Texas is such that plaster is not required for -warmth, and the walls 

are usually finished inside with other material. Since the price of 

lumber has advanced attention has been called to gypsum plaster for 

inside finishing. It moreover possesses the advantage of making a 

clean and hygienic wall.

DESCRIPTIONS OF LOCALITIES.

The largest area in Texas containing deposits of gypsum lies east 

of the foot of the Staked Plains, in northern Texas. The beds have 

an approximately northeast-southwest strike and extend from Red 

River to the Colorado in an irregular line, the sinuosities of which 

are produced by the .valleys of the eastward-flowing streams. This 

belt is a continuation of the deposits in Oklahoma which have been 

described as occurring in the Greer County region. Mr. Cummins in 

speaking of the belt says:

In Texas it reaches from the northern line of the State to the line of the Texas and 

Pacific .Railway on the south and is from 20 to 50 miles wide. The beds are of 

varying thicknesses, from that of a knife blade to 20 feet. The east line of the 

deposit begins on Red River near the mouth of the North Fork and extends to 

Sweetwater. * * * The western boundary is at or near the foot of the Staked 

Plains.«

The following sections from Mr. Cummins's report 6 will give an 

idea of the quantity of gypsum to be found at certain localities and 

the mode of its occurrence:

Section at Kiowa Peak, in the northeast part of Stonewall County, Tex., beginning at the

bottom.

Feet.

1. Gypsum ................................................................ 60

2. Red clay ................................................................ 20

3. Gypsum ................................................................ 20

4. Red clay ................................................................ 35

5. Gypsum ........................................ ...^.................... 15

6. Gypsum ................................................................ 4

Total............... 1................................................ 154

Section at Salt Flat, Kent County, Tex., beginning at the bottom.

, Feet.

1. Spotted red clay ......:...................-......-.......-.....-.......-. 3

2. White massive gypsum .................................................. 10

3. Red clay................................................................ 30

4. Gypsum ......................v......................................... 1

5. Red clay ................................................................ 30

6. Gypsum ................................................................ 6

7. Redclay................................................................ 20

8. Limestone................................'............................... 1

Total..,................................................:............ 101

«Second Ann. Kept. Gol. Surv. Texas, 1890, p. 450. blbid., p. 458.
uau] TEXAS. 71

The following section was made on the Salt Fork of the Brazos, in Kent County, 

in sec. 8 and block 1 of Houston and Texas Central Eailway surveys:

Section on Salt Fork of Brazos River, Texas.

Feet.

1 Bed sandy clay......................................................... 4

2. Massive white gypsum ................................................... 3

8. Red clay with seams of gypsum...................................... .... 10

4. Mottled sandstone ...................................................... 6

. 5. Red clay with seam of mottled sandstone. ^............................... 20

6. Mottled sandstone ........................i............................. 4

7. Red clay and mottled sandstone ......................................... 5

8. Massive white gypsum .................................................. 3

9. Red clay .......'...............................................,........ 10

10. Gypsum, alabaster...................................................... 1

11. Red clay'......................................-...-.--..-.-.....-..,..-.. 4

Total................................................................ 70

The following section was made 3 miles northwest of the abandoned smelter in 

Knox County.

Section in Knox County, Tex.

Feet.

1. Red clay ..............^............................j................... 20

2. White sandstone........................................................ 10

3. Red clay with gypsum .................................................. 30

4. Massive bluish gypsum.................................................. 2

5. Red clay................................................................ 20

6. Massive white gypsum ................................................... 4

7. Red clay.............................I................................. 20

8. Massive gypsum ........................................................ 1

9. Red clay with seams of gypsum.......................................... 30

10. Limestone ............................................................. 2

Total.............................................................!.. 139

In the eastern part of El Paso County, to the east of Guadeloupe 

Mountains, there is an area of gypsum which extends beyond the border of the State northward into New Mexico. It lies north of the 

Texas-Pacific Railroad and west of Pecos River. In a few localities 

this great plain of gypsum is overlain by beds of later limestone and 

conglomerate. The gypsum is conspicuously exposed along the course 

of Delaware Creek, a stream rising in the foothills of the Guadaloupe 

Mountains and flowing eastward into the Pecos.

The section of these beds is from 300 to 500 feet in thickness and 

contains gypsum in all its varieties and in varying degrees of purity, 

from the pure gypsum sulphate to mixtures with sand, pebbles, sulphur, limestone, etc. In color there is great range, white, red, and 

blue tints, however, prevailing. All the springs and streams within 

the area are strongly impregnated with gypsum, and in many instances 

with salt and sulphur.

In the Malone Mountains in El Paso County there is a third area 

which contains notable deposits of rock gypsum. This locality has 

the advantage of being situated near the Southern Pacific Railway,
72 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

and the outcrops are extensive and are favorable for working. It 

suffers, however, the disadvantage of being distant from market. The 

absence of sufficient water supply at this place is another serious drawback to its successful exploitation. 

Mr. Joseph A. Taff, in his paper describing this locality, says: a

The Malone bed is so named because of the great development of gypsum it 

includes which occurs in the Malone Mountains. * * * The main gypsum field 

extends from the center of the mountain to the northwest end. * * * The lowest 

rock exposed of the Malone Mountain horizon is a band of pale-yellow flaggy limestone. Above this limestone occurs the first horizon of white, friable, granular gypsum, having a thickness of 45 feet. Succeeding this gypsum there is 175 feet of massive blue granular limestone. * * * Above this limestone comes a second horizon 

of gypsum of a thickness of 110 feet. It is the same, lithologically, as the first horizon, 

' a stratified, nearly pure, friable, granular gypsum. It contains comparatively little 

earthy matter. * * * On the east side of the southeast end of Malone Mountain 

there is a development of gypsum with a surface area of about 40 acres. * * *

The clays and marls of the Cretaceous formation are frequently 

gypsiferous, though no deposits of economic importance have been 

found. Some of the occurrences of this nature are mentioned here 

since the content of gypsum is important in its relation to the soils 

derived from the beds. The Arietina or Del Rio clay contains normally large quantities of iron pyrite. Where it has been subjected to 

the process of weathering the oxidation of the pyrite has set free the 

sulphuric acid that it contains, and this in turn has combined with the 

lime in the clay to form gypsum. Crystals of selenite thus formed 

are often conspicuous in the outcrops. In the marls and clays of the 

Upper Cretaceous in the Trans-Pecos region, especiall}7 in Brewster 

County, are extensive beds containing selenite. In the Lower Cretaceous limestones, especially the Washita, in the neighborhood of 

the Terlingua mining district, extensive caves have been formed.

Often the caves have subsequently been 'filled Avith gypsum of a

variety of forms, including massive gypsum, selenite, and satin spar.

In that portion of Texas lying to the east of Brazos River there are 

numerous localities where the presence of g}7 psum has been noted. The 

geologic formations are of Tertiary and Quaternary age.

R. A. F. Penrose, jr., and William Kennedy, in their reports on 

this region, note the presence of gypsum, sometimes in considerable 

quantities, in the clays. In the Wills Point bed in particular, in 

Brazos County, gypsum, chiefly in the form of selenite, occurs in 

ci'3'stals which are sometimes 6 inches long and have attracted considerable attention, although they are of no commercial importance in 

view of the vast deposits which the State contains.

aSecond Ann. Kept. Texas Geol. Survey, p. 72.
H«I.L.J ' TEXAS. 73 

GEOLOGIC RELATIONS.

The gypsum deposits lying along the eastern foot of the Staked 

Plains and to the west of Pecos River occur in what are usually called 

the Red Beds of Texas. The deposits were probably formed continuously, although their outcrop is interrupted from Colorado River to 

the Pecos by the overlapping of later rocks. They have been referred 

to the Permian by Mr. Cummins, and have usually been considered as 

belonging to this age by other writers. The deposits in the Malone 

Mountains were considered to be of Cretaceous age by Mr. Taff, but 

the geology of the region is not clear. Mr. Stanton, who has subsequently studied these rocks, refers them to the Jurassic on paleontologic evidence. The age of the beds containing disseminated gypsum 

has been mentioned in the foregoing discussion of them.

Bull. 223-04 6
GTPSUM DEPOSITS IN MONTANA. 

By WALTEE HARVEY WEED.

CHARACTER AND EXTENT.

0 . . Gypsum deposits are widely distributed throughout the eastern 

flanks of the Rocky Mountain region of Montana, the beds embracing 

an extent of a great many miles. In general the gypsum occurs interbedded in a series of red and green shales with limestones containing 

Lower Carboniferous fossils. These beds vary from a few inches to 

6 or more feet in thickness, and the gypsum is often pure and free 

from foreign materials. The deposits so far developed are near the 

railroads in Carbon and Cascade counties, Montana. The rocks have 

been flexed by the mountain uplifts, and lie either at steep angles 

on the mountain slopes or in gentle dips at a distance of a mile or 

more away from them. The best development of the gypsum formation 

occurs near Kibbey, Cascade County, but the series of beds ma}^ be 

traced from Missouri River eastward along the flanks of the Big Belt 

Mountains to Riceville on the Neihart Branch of the Great Northern 

Railway; thence eastward to the town of Kibbey, and thence around 

the flanks of the Little Belt Mountains in a nearly continuous exposure 

to the vicinity of Castle Mountain. Southward from that locality the 

same horizon can be traced by its red shales, but the gypsum does not

occur, so far as known, in sufficient purity or thickness to promise commercial importance. Traced eastward along the flanks of the Rocky 

Mountains from the vicinity of Livingston to Carbon County, the 

same red series contains gypsum at various'intervals along the outcrop, 

but it is not until Carbon County is reached that the gypsum is known to 

occur in sufficient quantity to be of economic importance. This series 

of beds then extends southward into the Bighorn Basin and can be 

traced into the mountains of Wyoming.

Besides the geologic horizon just mentioned, gypsum occurs in 

abundance in Cretaceous beds, which are found through the eastern 

part of the State, but as a rule this gypsum is so disseminated through 

the shales that it can not be regarded as of any commercial importance. In rare instances it forms small veins which might be workable. Very commonly it impregnates the waters, both of streams and 

springs, making them unfit for use. At Hunters Hot Springs, on the 

north bank of Yellowstone River, about 20 miles east of Livingston, 

74
WEED.] MONTANA. 75

the hot Avaters are-now depositing gypsum and the old hot spring 

fissures are filled by a mass of gypsum and stilbite. Up to the present 

time these deposits, although of considerable extent, have not been 

utilized.

ECONOMIC DEVELOPMENT.

The gypsum deposits of Montana have been exploited at two localities, one in Cascade County near the toAvns of Kibbey and Armington, and the other in Carbon County near the town of Bridger. At 

Kibbey gypsum Avas mined and manufactured into plaster during the 

years 1898 and 1899, but in 1900 the plant was burned and has not 

been rebuilt. A company is now operating at Bridger.

GEOLOGIC RELATIONS.

The beds in Cascade County are unquestionably of Lower Carboniferous age. They lie directly above the heavy, massive, Avhite Carboniferous limestones, and are interbedded Avith shales and limestones 

carrying an abundance of Lower Carboniferous fossils of Spergeu 

Hill types. They are immediately overlain by Jurassic limestones, 

carrying typical fossils, and these in turn by a beach conglomerate 

which marks the uplift at the close of the Jurassic period. The 

Carbon County beds have not been critically studied. Their geologic 

relations, however, are believed to be the same as those in Cascade 

County.
GYPSUM DEPOSITS IN SOUTH DAKOTA. 

By N. H. DAKTON.

CHARACTER AND EXTENT.

In the Black Hills uplift there is brought to the surface an ellip- 

. tical outcrop of the Red Beds which give rise to the Red Valley surrounding the high ridges and plateaus of the central portion of the 

Black Hills. The area is about 100 miles long by 50 miles wide, and 

the outcrop zone has an average width of 3 miles, except in a few 

districts where the rocks dip steeply, where it is much narrower. The 

Red Beds have been designated the Spearfish formation, and while 

they have usually been regarded as of Triassic age, there is evidence 

that they may represent the Permian. The formation consists mainly 

of red sandy shales, with included beds of gypsum at various horizons, 

some of which are continuous for long distances while others are of 

local occurrence. The thickness of the deposits varies greatly, but in 

some districts over 30 feet of pure white gypsum occur, and nearly 

throughout the outcrop of the formation it contains deposits of sufficient thickness and extent as to have commercial value.

The gypsum is a prominent feature about Hot Springs. Here the 

principal beds occur about 60 feet above the base of the formation and 

have a thickness of 33£ feet, exclusive of the 10-foot parting of shale 

between them, but this thickness diminishes somewhat northward and 

rapidly southward. The following section is exposed on Cold Brook,

a short distance west of Hot Springs:

Section on Cold Brook, South Dakota.

Feet. 

Red shale and thin beds of gypsum .......................................... 5

Gypsum ....................................i.............................. 15

Red shale with thin beds of gypsuin......................................... 10

Gypsum ................................................................... 4$

Red clay................................................................... 1

Gypsum..........................................................."........ 14

Red clay................................................................... 2

Gypsum with clay partings ................................................. 5

Red shale with gypsum veins ............................................... 10

Gypsum ..............................I...............................^.... 3

Red clay with gypsum veins and nodules .................................... 7

Irregular breccia of gypsum.................................................. 2

Red clay with gypsum veins ................................... ............ 13

Red clay with a thin gypsum bed.......................... j ............... L.. 3

Banded red and white gypsum .............................................. 4

76
DAKTON.] 80UTH DAKOTA. 77

In the region north of Edgernont the principal bed of gypsum lies 

about 80 feet above the base of the Spearh'sh formation, and is continuous for many miles, with a thickness of 25 feet in most places. It

FIG. 16. Map showing gypsum-bearing formations in the Black Hills of South Dakota and northeastern Wyoming.

is exposed extensively about Cascade Springs and in the Red Valley 

east and west of Minnekahta station. The following analysis of a
78 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

typical gypsum from near Cascade Springs was made by Mr. Steiger 

in the laboratory of the United States Geological Survey.

Analysis of gypsum from near Cascade Springs, South Dakota.

Per cent. 

Lime (CaO) ............................................................. 32.44

Magnesia (MgO) ...........................................:........'.... .33

Alumina (A12 03 ) ..---.-......-......................-....-......:....... .12

Silica (SiOj,) ............................................................ .10

Sulphuric anhydride (S03)...........................................'....' 45.45

Carbon dioxide (C02 ) .................................................... . .85

Water (HgO) ...............................................' .......... . 20.80

Red shale ami thin beds of gypsum, 5 ft. 

Gypsum, 15 ft.

Red shale with thin beds of gypsum, 10 ft.

Gypsum, ±y, ft.

Keel clay, 1 ft.

Gypsum, H ft.

Retl olay, 2 ft.

Gypsum with clay partings, 5 ft.

Red shale with gypsum veins. 10 ft. 

Gypsum. 3 ft.

Red olay with gypsum veins and nodules, 7 ft. 

Irregular breccia of gypsum, 2 ft.

Red clay with gypsum veins, 13 ft. 

Red clay with a thin gypsum bed. 3 ft. 

Banded red and white gypsum. 4 ft.

PIG. 17. Section on Cold Brook three-fourths mile northwest of Hot Springs, South Dakota.

Total............................................................. 100. 09

East of Newcastle there are thick beds of gypsum in the lower portion of the Spearfish formation and a thick deposit at its top, which 

extends over an area of considerable size. The lower beds have a

thickness of 40 feet at some 

localities and the upper 

bed is 30 feet thick. A 

view of this upper bed, 

capping Red Butte, northeast of Cambria, is shown 

in PL XVI, A. About Sundance, and in the northern 

portion of the Black Hills, 

there is a continuous deposit of gypsum about 80 

feet above the base of the 

formation, which extends around the northwestern portion of the hills 

and thence southward for many miles. About Rapid the gypsum beds 

vary considerably in thickness, but 10 feet is the average. Portions 

of the Red Valley along the eastern side of the Black Hills are filled 

with thick deposits of White River formation which cover the Spearfish formation, but in exposures which are seen at intervals, the usual 

occurrence of gypsum is exhibited.

ECONOMIC DEVELOPMENT.

Owing to remoteness from market the gypsum deposits of the Black 

Hills have not been utilized to any great extent. A plaster mill at 

Hot Springs has been operated at times, and its yeiy satisfactory 

product has found ready market, but the expense of long shipment has 

greatly diminished the profits. Plaster of Paris has also been.produced 

to a moderate extent at Sturgis, especially for local use in Deadwood, 

Lead, and the other settlements of the northern Black Hills.
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. XVI

A. BUTTE OF RED BEDS CAPPED WITH GYPSUM EAST-NORTHEAST OF CAMBRIA,

WYO.

B. BLUFF SHOWING GYPSUM BED 1 MILE NORTHWEST OF HOT SPRINGS, S. DAK.
GYPSUM DEPOSITS IN WYOMING. 

By WILBUR C. KNIGHT.

CHARACTER AND EXTENT.

Although gypsum is scattered throughout a vertical range of more 

than 20,000 feet of sedimentary rocks in Wyoming, the deposits of 

economic importance are wholly confined to the Red Beds, which are 

largely made'up of red sandstones and shales. This formation, which 

is one of the most conspicuous in the Kooky Mountain region, outcrops about the base of most of the mountain ranges, or is exposed 

as the core of small or secondary folds, where erosion has been 

sufficient to remove the overburden. In all there are about 1,500 

miles of the gypsum-bearing formation exposed, and throughout this 

great linear extent it is the rule to find valuable beds varying from 5 

to 20 feet in thickness, and not an uncommon occurrence to find them 

from 30 to 50 feet thick. All of the gypsum that has thus far been 

tested is of excellent quality and can be utilized for the manufacture 

of any of the gypsum products. The beds are usually well located 

for economic development. In color the gypsum varies from snowwhite to pink and gray, but always burns to a snow-white.

Besides the rock gypsum there are secondary surficial deposits of 

impure gypsum, or gypsite, which occur in depressions below. It is 

only in recent years that deposits of this kind have attracted any 

attention, but now it appears that they will be more eagerly sought 

for than the rock gypsum. Little prospecting for gypsite has been 

done, but there is every reason to believe that Wyoming will furnish 

a large amount of this material. Deposits of this nature were first 

opened in the vicinity of Laramie several years ago, and there are 

numerous places where beds have been discovered along the base of 

the Laramie Mountains. Many other localities are favorable for the 

occurrence of secondary gypsum, and in time no doubt these beds will 

be reported from nearly every gypsum-yielding locality in the State.

ECONOMIC DEVELOPMENT.

Gypsum was first developed in Wyoming twelve or fifteen years 

ago, at Red Butte station, on the Union Pacific Railroad, about 9 or 

10 miles south of Laramie. A small plant for the manufacture of 

plaster of Paris and retarded plaster was erected, and this has since 

been in constant operation. This place was especialty favorable for

79
80 GYPSUM DEPOSITS I1ST THE UNITED STATES. [BULL.223.

launching the industry in Wyoming, since at that time it was the only 

one where the known, gypsum-bearing beds were crossed by a railroad. 

The mill is located near the quarry. A slight amount of surface 

material has to be removed. Below this there is a pure, almost white, 

deposit which is worked to a depth of from 8 to 10 feet. This, however, does not represent the entire thickness of the gypsum. In 

several other places beds have been opened, but owing to the lack of 

transportation it has been impossible to exploit them commercially. 

At Dayton, 16 miles west of Sheridan, a quarry has been opened, and 

also at Alcova; but these are too far from the railroads at present to 

warrant the erection of plants, except such as will supply the local 

demand.

Just south of the town of Lararnie a very large bed of secondary 

g}7 psum was discovered about eight years ago. A Kansas company 

purchased the ground and erected a large plant. Until last year the 

plant manufactured but a small per cent of the possible output. The 

plant was then absorbed by the Acme Company, and is now running 

full time. The product is shipped as far east as Chicago and westward 

to the Pacific coast.

The deposit at Lararnie is covered with about a foot of soil, which 

is removed by means of plows and scrapers. Below the'overburden 

there is 9 feet of gypsite without extraneous matter. It is plowed, 

taken up in wheeled scrapers, and hauled to the storehouse of the mill. 

The material as delivered by the scrapers is so-pulverulent that it is 

cooked without being ground.

The g}'psum beds in Wyoming are so numerous and of such extent 

and purity that with proper facilities for transportation the industry 

will become an enormous one in the future, and will be limited only 

by the demands for the output.

DESCRIPTIONS OF LOCALITIES.

Laramie Mountains. Along the western slopes of the Lararnie 

Mountains, gypsum beds have been traced, by occasional outcrops, 

from the Colorado line northward for a .distance of over 50 miles, and 

thence northwest 25 miles, to a point beyond Sheep Creek, where they 

disappear beneath the Tertiary formation. Near the Colorado line 

there are exposures of high-grade gypsum 50 feet in thickness, lying 

almost horizontally. To the north the beds thin out a little, but in no 

place have the}r been found too thin to work. All along this range 

the beds, dip only a few degrees to the west or the southwest. On the 

eastern slope of the Lararnie Mountains conditions are very different. 

From the Colorado line northward the Mesozoic and Paleozoic rocks 

are all tilted to the east at high angles, and were at one time all covered with Tertiary sediment as far north as Platte River. The excavation of the valleys has, however, uncovered here and there small
U. 6. OEOLOQICAL SURVEY ULLETIN NO. 223 PL. XVII

i YELLOWSTONE l^XC:Q

l^^- NATIONAL l "'

I ff 

I ($

50,.

SCALE

200 300 MILES

MAP OF WYOMING, SHOWING DISTRIBUTION OF RED BEDS, WHICH ARE GYPSUM-BEARING AT MANY LOCALITIES.
KNIGHT.] AVYOMING. 81

areas which show a'little gypsum, but nothing of commercial importance has been reported. From North Platte 

River in the vicinity of Cottonwood Creek to 

the northwest, and thence to the west to a 

point 10 miles west of Casper, there are extensive deposits near the foot .of the mountains. 

In fact the gypsum beds encircle the northwestern termination of the Laramie Mountains and extend a few miles to the southeast 

along the south side, to where the beds are 

covered with Tertiary rocks. This exposure 

is in reality the continuation of the beds on

tJypsum beds.

FIG. 18. General section of Red 

Beds in southeastern Wyoming, 

showing usual position of gypsum.

lied sandstones and shales. 675 ft.

Gray quartzlte, 5 ft.

Red sandstones and shales, 100 ft.

Red clays containing gypsum bands, !JO ft.

Gypsum, CO ft.

Gray and red sandstones, fosslllferons, 4 ft. 

Greenish and gray sandstone, 20 ft.

Red sandstone, 15 ft.

Red sandstonos and shales with hands of 

grits and conglomerates and one thin 

band of limestone, 68S) ft.

FIG. 19. Section showing the relations of gypsum in the 

section south of Laramio, Wyo.

Sheep Creek, which for a distance of 45= miles are obscured by more 

recent formations. Along the north side of the mountains the beds
82 GYPSUM DEPOSITS IN THE UNITED STATES. [BOLL. 223.

are of good thickness, but are as a rule steeply inclined. There 

is also a secondary fold just south of the town of Douglas that 

extends for 15 or 20 miles. Along it there are deposits of gypsum 

that have not been prospected. West of the Laramie Mountains, in 

the midst of the Laramie Plains, there are four anticlinal folds varying in length from 15 to 20 miles, all of which have exposures of 

gypsum-bearing rocks on their flanks, and two of these contain large 

areas of beds that are in rather close proximity to the Union Pacific 

Railroad.

Medicine Bow Mountains. About Elk Mountain, the northern termination of the Medicine Bow Range, there are extensive beds of 

gypsum which are exposed, but along the eastern and western flanks 

the gypsum-bearing formations are nearly or quite obscured by debris 

from the higher portions of the mountains or by Tertiary rocks.

Rawlins uplift. The Red Beds encircle the Rawlins uplift, but for 

many miles they are covered with sand and soil. Along 'the eastern 

slope of the arch the beds dip gently to the east, and at a point 14 

miles north of Rawlins the gypsum has been discovered. Along the 

western slope the beds are highly inclined, and in several gulches 

good gypsum has been found. Where the railroad crosses this uplift 

the Red Beds are entirely covered with soil to a considerable depth. 

Thus far the thickness of the gypsum beds has not been determined.

Freezeout Hills. The eastern termination of this uplift is about 15 

miles north of Medicine Bow, a station on the Union Pacific Railroad 

in Carbon County. This is a broad anticlinal arch having a length of 

about 15 miles, and striking nearly east and west. The dip to the 

north and south is less than 10°, and there are not less than 20 miles 

of very thick gypsum beds surrounding this uplift.

SUrley Mountains. This range, which is just west of the Freezeout Hills, is not over 8 or 10 miles in length. Its trend is northwest, 

and along the southwestern base there are several places where gypsum has been "discovered, but nothing is known of its importance. 

On the north side of the range the Red Beds are not exposed.

Seminole Mountains. There is a narrow synclinal valley between 

the Shirley Mountains and the eastern termination of the Seminole, 

which is composed mostly of Red Beds. They outcrop around that 

portion of the Seminole Mountains lying east of North Platte River, 

and extend along the southern border from Platte River westward for 

a distance of about 10 miles. On the north side of the eastern termination of the mountains the gypsum rocks are entirely obscured by 

late Tertiary beds. Along this range there are numerous exposures 

of beds of considerable thickness, but no work has been done to 

develop them.

Ferris Mountains.- Along the southern base of this range there are 

gypsum beds exposed where the gulches and canyons have cut a.cross
KNIGHT/] WYOMING. 83

the formation, but nothing definite is known of the importance of the 

beds. This range being a fault block, there are no exposures along the 

northern slopes. Northwest of the Ferris Mountains there are two 

other mountain-like masses that are imperfectly known, the farthest 

being called Green Mountain. Gypsum has been found near both of 

them, but there is no reliable information concerning the characters 

and thickness of the beds.

Rattlesnake Mountains. This is a fault rapge about 60 miles west 

of Casper, having a general northwest-southeast course. Along the 

northeastern base the gypsum-bearing formation extends upward of 

20 miles, and dips 25° to 30° NE. The beds are very thick, but have 

not been carefully studied.

Conn ant (7ra?&. Forty miles west of the Rattlesnake Mountains 

there is an anticlinal fold which extends out from beneath the high 

Tertiary bluff of the Rattlesnake Mountains westward to Beaver Creek.

About the termination of this fold beds of g}r psum of sufficient thickness to make them of commercial importance outcrop for several miles.

Grand Canyon of the Platte. Just below this canyon there is a 

broad valley that has been carved out of the Tertiary rocks. The 

removal of the Tertiary has exposed two rather extensive areas of 

Red Beds. The first is at the mouth of the canyon, at which place 

the gypsum beds are well developed and have a linear extent of not 

less than 5 or 6 miles. Below the canyon about 3 or 4 miles, and at 

the town of Alcova, the Red Beds have been brought to the surface 

\)y means of a fault, in an area similar to the one just described. The 

gypsum at this place has been prospected, and very valuable beds are 

open and awaiting transportation facilities.

Bighorn Mountains. This range is practically surrounded with 

gypsum-bearing beds. Along the northern and eastern base the formations are nearly vertical. Along the center of the uplift opposite 

Buffalo, and for miles on either side, the upturned edges of the 

Paleozoic and Mesozoic rocks have been covered with a large amount 

of debris from the mountains. From the northern end of the range 

to the southeast, nearly' to Bighorn, the beds are well exposed and 

are of the usual thickness and quality. About 10 or 15 miles south 

of Buffalo the gypsum beds also appear on the surface, and can be 

traced with but few interruptions until the Tertiary beds are reached 

southeast of Lost Cabin. On the western slopes the beds are fully as 

extensive. They dip much more gently than on the eastern slope, and 

accordingly have more conspicuous outcrop. These beds are nearly 

continuous from the north end of the range to Thermopolis, and all of 

the g}7psum bands noted have proved thick enough to warrant working. 

At present the railroad nearest to these beds is the Burlington, and it 

will probably be a number of years before the deposits will be 

developed, although the gypsum is of a superior quality.
,84 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

Owl Creek Mountains. This range is in reality the western continuation of the Bighorn system, which finally abuts against the 

Shoshone Mountains. This mountain chain is a rather narrow fold, 

having a core of Paleozoic rocks, with gypsum beds outcropping upon 

either side.

Absaroka Mountains. These mountains are largely made up of 

volcanic breccia, which forms a covering several thousand feet deep 

over sedimentary rocks that had been previously tilted. In consequence no gypsum-bearing beds of importance outcrop except in 

localities where erosion has removed the covering or where the Red 

Beds were not concealed by the breccias. Most of the gypsum-bearing 

rocks of this range occur between the Montana line and Cedar Mountain, which is a few miles west of Cody. Nothing of importance has 

been found out about this region further than that the Red Beds 

contain gypsum.

Prior Mountains. The Prior Mountains are largely in Montana, 

but there is a prominent spur extending southeastward into Wyoming 

along which the gypsum-bearing formation has bean traced as far as 

the mouth of Grey Bull River, but this probably is not the southeastern limit. There is also a secondary fold between the Prior Mountains and the Bighorn Range, along which there are Red Beds outcropping. All this region is very rich in gypsum, and it is exposed 

for many miles. It resembles in quality that found in other parts of 

the State.

Wind J2iver Mountains. From Miners Delight .westward along the

foot of the Wind River Mountains, and thence northward nearty to

the big bend in Green River, the Red Beds are nearly all obscured by

Tertiary rocks, glacial debris, or materials that have been transported

. by the streams. From the head of Red Canyon, near Miners Delight,

to tjae northwest, along the eastern slope, these beds are continuous 

for a distance of nearly 100 miles, being only now and then obscured. 

All along the range where observations have been made there are 

thick beds of gypsum that dip moderately to the northeast. Parallel 

to this range, and only a few miles northeast, there is the Shoshone 

anticline, and along it for a distance of nearly 40 miles gypsum beds 

are exposed. No attempt has been made to prospect or develop the 

very thick beds that are known along this great mountain chain.

Oros Venire Mountains. Red Beds containing heavy ledges of 

gypsum are known at many places about this range. The country has 

been included in the forest reserves, and owing to the lack of transportation it will be many years before there will be any value placed 

upon the gypsum, although it is of excellent grade and occurs in very 

thick beds.

Salt Creek Range. This area ma}r be considered as including all of 

the territory between the Oregon Short Line Railroad and the Gros
KNIGHT.] WYOMING. 85

Ventre Mountains. Within it are several north-south folds, along 

which there are extensive exposures of Red Beds which not only contain gypsum, but also salt, as farther south in the State of Utah. 

Very little is known concerning the deposits of this portion of Uinta 

County, except that they are plentiful.

BlaGlt, Hills. There is a broad belt of Red Beds encircling the western base of the Black Hills in which gypsum is abundant. These 

have been discussed by Mr. Darton in connection with the South 

Dakota deposits.

GEOLOGIC RELATIONS.

As previously .stated, the deposits in,the State of economic importance are confined to the Red Beds, which have for years been called 

Triassic.' Mr. Darton in describing the Red Beds of the Black Hills

region has called the gypsum-bearing portion the Spearfish formation

and referred it to the Triassic(?). The Red Beds are a very conspicuous feature in Wyoming geology. They vary in thickness from 1,000 to 

1,600 feet, and are composed largely of red shales and red sandstones, 

which are frequently cross-bedded. Above these rocks the Jurassic 

series is found, except in places where it has been removed by erosion. 

In the lower part of the section there is some variation, owing to the 

fact that the basal portion of the Red Beds in the southern portion of 

Albany County is equivalent to the limestones and sandstones farther 

north. In a few localities the Red Beds rest upon the Archean, but as 

a rule they are 'conformable upon limestones or a series of alternating 

limestones and sandstones. These limestones and sandstones have been 

referred to both the Permian and the Upper Carboniferous. Thus far 

the paleontologic evidence has been entirely insufficient to place them 

with any certainty in either. From investigations carried on in the 

La.ramie Mountains it is quite reasonable to believe that the sedimentary rocks directly below the Red Beds will be classed as Permian, and 

that all of the Red Beds of southeastern Wyoming will also be referred 

to this series. Recently a fauna has been discovered in the midst 

of the Red Beds near the Colorado-Wyoming line which places the 

lower half of the Red Beds of that region unquestionably in the Carboniferous, and there is no reason for placing the upper division in 

any other system. The rocks of the southeastern portion of Wyoming 

should, accordingly, no longer be referred to the Triassic. The 

sections in the western part of the State resemble to a marked degree 

those made in the eastern, and it is quite probable that the Red Beds 

there also will prove to be Paleozoic, and perhaps Permian. From 

what is known at the present time it is believed that the gypsumbearing beds of Wyoming will prove to be Permian.
GYPSUM DEPOSITS IN COLORADO. 

By ARTHUR LAKES.

CHARACTER AND EXTENT.

The gypsum which is worked in Colorado consists of massive beds 

which outcrop at intervals from the northern to the southern border 

of the State, along the eastern foothills of the Rocky Mountains. In 

addition, there are a number of localities where deposits of considerable 

importance have been noted. They may be of economic value, but thus 

far there has been no necessity of exploiting them. There are a few 

small deposits and. certain local occurrences of gypsum which are of 

interest because of their relation to ore deposits. Some of the shale 

formations are gypsiferous to a marked degree, so that the water 

derived from them contains a notable amount of g}7 psum. When the 

shale is manufactured into bricks, the gypsum they contain gives them 

a spotted appearance. The amount of gypsum in the State is far in 

excess of any prospective demand. The deposits already developed 

reach a thickness of 30 feet in places, and some of them are of very 

satisfactory quality. The deposits that are favorably situated with 

respect to transportation facilities and that are composed of rock of 

high grade are the only ones which can be expected to become of commercial importance.

ECONOMIC DEVELOPMENT.

Gypsum has been worked extensively near Loveland; beds have also 

been opened on Bear Creek, near Morrison, and 8 miles to the southeast, on Deer Creek. Quarries have been developed near Perry Park 

and in the Garden of the Gods, near Colorado City, and in the vicinity 

of Canyon there are beds which have been utilized to some extent. 

During the last few years the industry has been confined principally 

to Loveland, Perry Park, Colorado City, and Canyon, and has shown 

considerable variation in activity.

DESCRIPTIONS OF LOCALITIES.

But few of the localities in the State have been especially studied

with respect to the occurrence of g}rpsum beds. The one to which the

writer has devoted the most attention is at Loveland. It is situated at

the eastern foothills of the Rocky Mountains, where the strata have

86
LAKES-1 COLOEADO. 87

been folded. The formations have dips varying according to their 

positions on the arches and anticlines. In the vicinity of 

the quarry at Loveland erosion has removed the rocks so . 

as to form an amphitheater-like basin, and the exposed 

edges of the strata circle around a granite spur. The bed 

of gypsum lies near the top of the arch of the main axis of 

the anticline. It is interbedded with siliceous limestones 

and red marls. The face of the quarry exposes the rock 

for a distance of about 250 feet, and the bed has a maximum thickness of 28 feet, with a minimum of 7 feet at 

places along the outcrop. The dip of the bed is about 

15° N. The gypsum is very compact, of a drab-gray 

color, and is uniform in appearance and quite free from 

impurities where it has not been altered by surface decomposition. In two or three places a strip of red clay i

follows the joints which cut the bed. The gypsum de- '

posit is traceable down the center of the basin, and i

appears to be of inexhaustible quantity. i

The deposits near Morrison, on Bear Creek, and on \

Deer Creek are evidently local beds in the same series i

that is found at Loveland, and outcrop in the upturned i

edges of the rocks a short distance east of the foothills, i

The extent of the beds is not known, but their thickness i

on Deer Creek is about 20 feet. The deposit at Perry i

Park is, in the same geologic series and has been ex- j

tensively worked. A detailed description of the locality j

is not available. In the Garden of the Gods, near Colo- i

i rado City, where the rocks have fantastic forms and are !

found outcropping practically on edge, the gypsum bed is i 

conspicuous because of its whiteness. The gypsum has a j 

fine alabaster texture and shows narrow seams of so- < 

called satin spar. From the beds on Fountain Creek | 

material is derived from which statuettes of so-called 

alabaster and plaster of Paris are made. The deposits 

are of fine quality, but individual beds without clay seams 

or impurities are not large. Similar deposits are found 

at Canyon, on the Arkansas, and southward from this 

point to Trinidad; but no precise knowledge or record 

of them can now be given. In the southwestern portion 

of South Park, in the vicinity of the salt works, gypsum 

is known to occur, but has not been developed.

In the western part of the State, near the station 

of Gypsum, on the Rio Grande Railroad, between Leadville and Glenwood, and at the same geologic horizon 

on Roaring Fork, between Glenwood and Aspen, 

there are gypsum deposits which may prove to be of economic value.
GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

In southwestern Colorado, to the east of the La Sal Mountains, in 

the area drained by the Rio Dolores, important deposits of gypsum 

occur in the Red Beds and also in lake deposits, which, are probably of 

Tertiary age.

In the San Juan mining region, and also in the vicinity of Durango, 

gypsum occurs in the Hermosa formation, as has been noted by Mr. 

A. C. Spencer/4 This formation consists of limestones, green sandstones, and shales, with some beds of gypsiferous shales.

In the vicinity of Newman Hill, at Rico, there is a bed of rock 

gypsum having a thickness of 30 feet in certain places. Mr. F. L. 

Ransome, who has studied the ore deposits of this place, has shown 

that the occurrence of the gypsum in the blanket zone is a matter of 

considerable theoretical and practical importance. 6 The gypsum has 

largely been dissolved, and the solution has been accompanied by the 

accumulation of a silty residue. In certain places where the gypsum

Soft sandstone 

Dark shales

Gypsum

Blanket limestone Dark shale 

Sandstone 

Dark shale '

FIG. 21. Diagramatic section through a portion of the Enterprise blanket, showing relation of the 

gypsum -to the blanket, Rico, Colo.

occurs no ore is found, but where the gypsum has been dissolved away 

the blanket zone has been mineralized.

Small bodies of gypsum of secondary origin, resulting from the 

reaction of the sulphate, solutions of mine and ground waters upon

limestones, are found in many of the mining districts. This has been 

recognized by Mr. Ransome as actually taking place inC HC Hill, but 

the gypsum formed at that place is merely a dull earthy crust on the 

limestone, and is evidently dissolved nearly as fast as it is formed, 

and consequently attains no considerable size.

GEOLOGIC RELATIONS.

The gypsum found along the eastern foothills of the Rocky Mountains is in a series of red sedimentaries which has usually been referred 

to the '' Juratrias." The formations are destitute of fossils, and the 

gypsum was apparently deposited from landlocked bodies of sea water. 

The deposits in the west-central part of the State and in the Hermosa 

formation are of Carboniferous age.

a Geology of the Rico Mountains: Twenty-first Ann. Rept. U. S. Geol. Survey, pt. 2, 1900, pp. 48-54. 

6 Ore deposits of the Rico Mountains, Colorado: Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 2, 

1901, pp. 273-280.
G-YPSUM DEPOSITS IN NEW MEXICO. 

By H. N. HERRICK.®

CHARACTER AND EXTENT.

Gypsum is found so generally distributed in New Mexico, and 

occurs in such vast deposits and in such variety of forms, that the

FiG. 22. Map of New Mexico showing approximately the area of the Red Beds, which are gypsum

bearing at numerous localities.

supply is practically inexhaustible. Until 1902, however, no attempt 

toutilize.it in a commercial way had proved successful. A number

«In the preparation of this paper use bus been made of the field notes and publications of Prof. 

C. L. Herrick.

Bull. 223-04 7 ' 89
90 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

of efforts have failed because of excessive freight rates and small 

market. Gypsum is used to a limited extent by the Mexicans, who 

generally have in their villages a pile of ' hieso, which is calcined in 

ovens as needed and used for plastering the interior of their houses. 

Some has also been ground and used as land plaster in attempts to 

reclaim alkali lands, the gypsum reacting in such a way as to transform the "black alkali" to a less harmful salt. Gypsum is the only 

substance which has been shown to benefit these lands, but its effect is 

slow and its use expensive. There is not as yet much demand for it 

for this purpose.

For the manufacture of plaster and cement there is but one plant in 

the territory, that of the Rock Island Cement and Plaster Company, 

located at Ancho, on the line of the Rock Island Railroad. At the 

time the works were visited only a small testing plant was in operation, a large mill being in process of construction. In the low, wooded 

foothills of the White Mountains, which surround this, place, there 

are conspicuous exposures of gypsum and anhydrite. The following 

section was taken from the highest hill in the neighborhood, at a 

place where a quarry had been begun: .

Section in foothills of White Mountains, New Mexico.

Feet.

Soft, gray sand and shales ............................. ..................... 85

Limestone ........................... ..................................... 7

Pure massive anhydrite..................................................... 12

Earthy anhydrite .......................................................... 5

Massive anhydrite............ .............................................. 15

Limestone ................................................................. 2

Anhydrite................................................................. 4

Limestone................................................................. 1

Massive anhydrite.......................................................... 35

Limestone................................................................. 5

Gypsum, bottom.

The material used is the disintegrated anhydrite and gj^psum, which 

occur as a surface deposit and have a thickness in places of from 10 to 

20 feet. This gypsum dirt or gypsite is simply scraped up, put 

through coarse screens, and calcined in iron hoppers, after which it is 

put through a 35-mesh screen and is ready for use. It is claimed that 

the organic and other impurities in the gypsite make the use of the 

usual retarder unnecessary, thus doing away with one of the principal 

sources of expense. The finished cement needs only to be mixed with 

from three to four parts of sand before using. It is light gray when 

set, and houses in which it is used as mortar or outside finish are not 

only neat in appearance, but resist weathering remarkably well.

GEOLOGIC OCCURRENCE.

With the exception of certain gypsiferous shales in the Cretaceous, 

the gypsum-bearing deposits in New Mexico occur in what are known 

as the Red Beds. The Red Beds have not been studied sufficiently as
HBKBICK.] NEW MEXICO. 91

yet to permit close classification. In the vicinity of Mesa Gigante 

three divisions are recognized, which are distinguished largely by their 

colors. The lower or Red division is the only one containing any considerable number of fossils. It is referred to the Permian on paleontologic grounds. Near the top of this division the gypsum horizons 

are generally found. Above the Red division is the Chocolate series, 

of a darker red, and at the top is the Vermilion series. The lowest 

division usually contains some bands of limestone or lime breccias, 

which are a very characteristic feature, and is of an average thickness 

of about 500 feet. The Chocolate division is about 600 feet in thickness and is composed of quartzites and gray and red sandstones, passing 

gradually into the loose, bright-red marls and clays of the Vermilion 

division. . The Chocolate and Vermilion series have been referred to 

the Triassic and Jurassic for stratigraphic reasons, but it may be 

that they are only a continuation of the Permian. It can not be said

with certainty that this threefold division is maintained throughout 

New Mexico, since -detailed study has been possible at only a few 

localities. Considerable variation in lithology has been noted, and 

possibly the color is not a reliable guide. So far as observations 

have been made on the conditions of sedimentation they point to 

shallow-water deposition in the northern and northwestern portion of 

the Territoiy, and to the prevalence of conditions favorable to the 

deposition of limestones at recurring intervals in the southern part. 

For the purpose of discussion, the Territory may be divided into three 

regions. The eastern one lies principally in the valley of the Pecos, 

and is connected with the Red Beds area of northern Texas by an arm 

extending along Canadian River. The central division is drained by 

the Rio Grande and its tributaries. The western division is in the 

region of the Zuni Mountains. These divisions are made simply for 

the purpose of discussion, and are not based on geologic differences; 

neither are they geographically distinct.

DESCRIPTIONS OF LOCALITIES. 

EASTERN NEW MEXICO.

The largest area of the Red Beds in New Mexico lies in the eastern 

part of the Territory, principally in the valley of the Pecos. It has 

not been studied excepting in reconnaissance, but an attempt has been 

made to show its extent on the accompanying map.

Along Canadian River an arm of the Red Beds extends from New 

Mexico into Texas, connecting with the vast area in northern Texas, 

Oklahoma, and Kansas. These exposures are of interest since they 

show the continuity of the Red Beds and indicate that the conditions 

of sedimentation were similar over a wide area. The beds along the 

Canadian are exposed as a result of the removal of the Tertiary deposits 

which form the High Plains, or Staked Plains as the}7 are called in
92 GYPSUM DEPOSITS TTC THE UNITED STATES. [BULL.223.

Texas arid New Mexico. This has been accomplished by the river in 

the process of eroding its valley. From these exposures and the relations of the formation in general it may be inferred that the Red Beds 

are probably present under a considerable portion of the Staked Plains.

Lower Pecos Valley. In this region the area of the Red Beds is relatively narrow as compared with the upper portion of the valley. It 

is limited by the Staked Plains to the east and the mountains to the 

west. There are frequent exposures of gypsum, and the presence on 

the map of such names as Salt Lake, Salt Spring, Alkali Flat, Tierra 

Blanca Lake, Arroyo Hieso, etc., indicates the general character of the 

country.

Plain west of the Upper Pecos. This whole region is one of alkali 

flats, salt lakes, and sandy hills, with a few isolated peaks, such as the 

Cerro del Pino and Pedernal Mountain.

The western portion of the area, covered by the Antonio Sandoval 

grant, contains several especially large salt lakes, which have been a 

well-known and much-used source of salt as far back as history and 

tradition go. In most of these lakes the salt has been deposited on 

the bottom in layers from one-half inch to 3 inches thick, alternating 

with layers of gypsum. In the largest lake the upper layer of salt is 

about 8 inches thick, and the water is a saturated brine. In the banks 

of the depressions in which the lakes are located exposures of shales 

with bands of gypsum are found, and on the side of the Mesa Jumenez, 

on the southern edge of the plain, a thick bed of impure gypsum and 

anhydrite is exposed for miles. On the western edge of the plain are 

exposures of the Upper Carboniferous, which, however, dip toward 

the east at an angle that should bring the Permian to the surface 

before the lakes were reached. Wells sunk in the eastern part of the 

plain penetrate layers of gypsum, and it is evident that the gypsiferous

horizon can not be far below the surface at an}^ point. It is a curiOUS 

fact that the water of these wells, as also that of the few springs, is 

not only brackish, but smells strongly of sulphureted hydrogen. 

Some of these wells are 20 miles from any place showing evidence of 

volcanic action, and the only explanation that suggests itself is that 

there may be some reaction between the calcium sulphate and organic 

matter in the soil which liberates this gas/'

Where Pecos River cuts the plain there is another exposure of the 

Permian with its beds of gypsum, and the streams are impregnated 

with salt and alkalies.

Coyote Creek. To the north and west of the city of Las Vegas the 

Red Beds are frequently exposed, but thus far no extensive gypsum 

deposits have been encountered. The sequence of strata seems to be 

similar to .that of the northwestern portion of the Territory, rather

«For more complete discussion see Johnson, D. \V., .Notes of a. geological reconnaissance in eastern 

Valencia County, N. Mex.: Am. Geol., Feb., 1902.
ItURBlCK.} NEW MEXICO. 93

than to that of the southeastern. Careful stratigraphic work is lacking for this region, but the existence of extensive deposits of copper 

in the shales of this series is especially noteworthy. In the valley of 

Coyote Creek, in Mora County, east of the town of the same name, is 

a very characteristic exposure illustrated in a general way by fig. 23. 

To the west is a great granite uplift, bearing on its summit fragments 

of the Carboniferous series, to the east is a sharp monocline dipping 

eastward, composed, apparently, of the sandy base of the Cretaceous, 

while the interval between contains the nearly vertical strata of the 

Permian or "Permo-Carboniferous," with the characteristic red sandstones and chocolate shales of the former and the bedded fossiliferous 

limestones of the latter division. For man}7 miles north of this 

locality tbe carbonaceous and micaceous, shales contain disseminated 

flakes and larger nodules of copper, replacing organic matter, the 

intevbedcled sandstones here having been converted by local metamorphism into dense quartzites. The whole formation farther north is 

covered by an extensive flow of recent basalt.

FIG. 23. Diagrammatic section north of Lucero, N. Mex., in valley of Coyote Creek.

Southeast of Las Vegas, Passing southward from Las Vegas 

strata successively lower in the series are crossed, the upper Red Beds 

appearing in well-defined escarpments about 20 miles southeast of Las 

Vegas. Pecos River is bordered by exposures of the Red Beds for a 

large part of its lower course. The southeastern boundary of the 

Anton Chico grant is marked hy a profound fault, known locally as 

El Alto de Los Enteros, and the walls of the canyon for several miles 

below display the effects of local metamorphism. A remarkable 

exaggeration of the sandy strata in R. 21 E. produces a sharp curvature in the river north of the Pecos grant. These sandy strata, occupying a position above the gypsiferous layers, are impregnated with 

asphalt, and have given rise to great expectations of oil. The record 

of a well upon the Perea grant, bored to a depth of 770 feet, showed a 

prevalence of gypsiferous shales beneath the asphalt layer. The 

existence of soluble deposits in these beds is proved by the numerous 

"sink holes" in the region north of Santa Rosa. On descending the 

Pecos successively lower strata of the Red Beds are reached, till in 

Arroyo Salado gypsum and foliated limestone are found at the surface.
94 GYPSUM DEPOSITS IK THE UNITED STATES. [BULL. 223.

RIO GRANDE VALLEY OR CENTRAL REGION.

Chama Valley. In the absence of personal investigation north of 

the Jemez Range reference is here made to Professor Cope's account 

of the stratigraphy north of the Nacimiento Mountains."

The region seems to be very similar to that south of the Nacimiento 

Mountains, on the headwaters of the Rio Jernez and Rio Puerco, 

described below. In the canyon of the Cangilon, which is tributary 

to the Chama, Professor Cope found the Red Beds, with layers of 

gjrpsum 50 feet thick in places, separated from the lowest Cretaceous 

by an interval of about 850 feet of mud-brown sandstone. Below the 

gypsum is a lemon-yellow band, and below this are beds of vermilionred sand. The gypsum was supposed to mark the top of the Jurassic,

the thickness being given as 600 

feet, below which were 1,000 feet 

of Triassic, the bottom of which 

was not seen. The mud-brown 

sandstone above the gypsum is 

regarded as the equivalent of Cretaceous No. 1 of Hay den's section 

at Colorado Springs. Above this 

is Cretaceous No. 2, 1,500 feet 

thick, composed mainly of shales, 

and this is followed by the sandy 

Cretaceous No. 3, also 1,500 feet 

thick. Professor Cope reports 

the lower beds of the red series 

to be of fresh-water origin, as 

they contain unios and saurian 

remains. He also states that the 

Jurassic beds contain conglomerate lime strata and copper.

Headwaters of the Rio Puerco and Rio Jemez. All along the western base of the Nacimiento Mountains are. exposures of the Red Beds 

with thick bands of gypsum and gypsiferous shales high in. salines 

(fig. 24). The Rio Salado, which is a tributary of the Rio Jeinez, is so 

salty that its water is unfit for domestic use. It derives its salt from 

the formations along the western base of the Nacimiento Mountains, 

and carries a great part of the salt and alkalies deposited by the Rio 

Grande on the flats along -its valley above the mouth of the Puerco. 

The Rio Puerco also flows along the western 'edge of the Jemez Range, 

farther north than the Salado, and there obtains the salines and alkalies and the dark-red sediments to which it owes its name. In this 

region there are deposits of copper which are mined at Copper City, 

on the western slope of the range. The copper occurs in a sort of

Yellow sand. 125 ft.

Brown shaly phase.

Chocolate shales, gypsiferous. 250 ft.

Thin limestone. 

Anhydrite and gypsum, 40 ft. 

B Vermicular shale. 10 ft.

Lower white sandstone, 40 ft.

Friable sandy shale, 128 ft.

FIG. 24. Section west of Nacimiento Mountains, 

New Mexico.

«U. S. Geog. Surv. W. 100th Mer., vol. 4.
DERRICK.] NEW MEXICO. 95

loose conglomerate of the Lower Permian, and the proximity of the 

gypsum beds in this and other places has led prospectors to regard 

gypsum as a favorable indication when looking for copper.

In the region near Jemez Peak the coloration of the exposed Permian is especially brilliant, the bright-red bands of sandstone and shale 

contrasting with the white gypsum beds in a most startling way.

On the western slope of the Nacimiento Mountains the base of the 

" Permo-Carboniferous" series is well exposed, consisting of earthy 

limes and shales, often exceedingly fossiliferous. The narrow bands 

of lime breccia with included fragments of clay ironstone, eveiywhere 

characteristic of the transition beds throughout the Territory, are 

generally present. Conglomerate's composed of materials from the 

granite axis of the range constitute another characteristic feature and 

furnish evidence of littoral conditions.

East of the S.mdia Mountains. East of the Sandia Range, which

is formed by an uplift of granite, 

capped by Upper Carboniferous 

limestones and quartzites, is a succession of faults, the effect of which 

is to bring to the surface successive 

portions of the lied Beds and overlying Cretaceous. The enormous 

development of the massive red sandstones of the lower portion of the 

series, as exposed east of Tijeras Canyon, is very characteristic. These 

frequently contain trunks of trees, 

often altered to copper and iron 

ores. Above this red division are 

exposures of gypsum and anhydrite 

uniformly reposing on the vermicular shales elsewhere noted in this 

paper. Curiously enough, the anhydrite seems at this point to be at 

or near the top of the Red Beds, although it is impossible certainty to 

determine whether the juxtaposition to the Lower Cretaceous is not 

due to dislocation. In shales a short distance above a quartzite which 

here forms the top of the "Permo-Carboniferous" was found a series 

of fossils of undoubted Permian age. The remainder of the Red Beds 

have yielded no other fossils in this region than the tree trunks already 

mentioned. The prevailing sandy character and the inclusion of 

granite fragments in the Red Beds sufficiently indicate their littoral 

character at this place.

East of the Manzana Mountains and Socorro. The region immediately east of the Manzana Mountains resembles the Sandia region and 

offers numerous exposures of the red, indurated sandstones and shales. 

Southward, however, calcareous beds are found in the section, and the

wxxftQO

Earthy limestcme, 135 ft.

Gypsum and yellow sand, 15 ft

Gypsum, 30 ft.

Limestone.

White sand, flOft.

Yellow sand, 115 ft.

Keddish sand.

Limestone and gypsum, 50 ft. 

FIG. 25. Section northwest of Pyramid Mountain, New Mexico.
GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

formation resembles more or less that of the Red Beds of the southeastern part of the Territory. East of the town of Socorro are 

numerous extensive escarpments embracing hundreds of feet of limestone and gypsum or anhydrite not observed farther north. Fig. 25, 

which is a section taken northwest of Pyramid Mountain, shows the

FIG. 26. Section at Pyramid Mountain, New Mexico, showing basalt cap lying on gypsum.

existence of about 200 feet of earthy limestone above a still thicker 

series of sandstones and interbedded anhydrite and gypsum. Twenty 

miles northeast of Socorro is Pyramid Mountain, which is an isolated 

basaltic cone reposing directly upon a gypsif erous member of the Red 

Beds (fig. 26).

FIG. 27. Section at Mesa Gigante, north of Rio San Jose, N. Mex.

.Valley of the San Jose. An area of the Red Beds occurs in the 

country traversed by the San Jose. It is bounded on the north by the 

extensive Mesa Gigante and Mesa Negra, the southern escarpments of 

which present very complete sections of the Red Beds series up to the 

Cretaceous. The threefold division is here very conspicuous. At

100 ft. massive sandstone.

75 ft. bedded sandstone.

a5 ft.

25 ft. gypsum.

3 ft. vermicular shale.

30 ft. red sandstone, limestone, Ironstone concretions.

75 ft. massive sandstone.

Conglomerate. 

Friable sandstone.

FIG. 28. Section at El Rito, New Mexico, 8 miles east of Laguna.

the base is a comparatively small series of limestones and shales, followed by red sandstones and marls, pink sandy marls, and white sandy 

marls, to the base of the. gypsum deposits, which are irregular, often 

lenticular in shape. The chocolate beds of sandstones and shales are 

recognized by their characteristic color, and are followed by the
HfcKRICK.] NEW MEXICO. 97

so-called Vermilion division. The gypsum varies in thickness from 25 

t'o 75 feet and in this region occupies a rather constant horizon. 

Beneath it a vermicular shale 3 to 5 feet thick is very regular in its

FIG. 29. Section northeast of El Rito station, New Mexico, showing basalt dike penetrating the

gypsum-bearing series.

occurrence. The gypsum is especially well exposed near the western 

boundary of the Quelites grant, where massive anhydrite occurs in beds

over 50 feet thick. An extensive fault and monocline running north 

and south separates the Red Beds from the Cretaceous to the east.

The accompanying sections at 

Mesa Gigante (fig. 27) and 

at El Rito, near Laguna (figi 

28), show the relations of the

Igneous cap.

Deep red sandstone and shales, 300 ft. gypSUHL, and tllC CUllOUS i

penetration of basalt, which is 

of common occurrence around 

the margin of the great Mount 

Taylor lava flow, is shown in 

fig. 29.

Valleys of the Rio Salado 

and Rio Alamosa. The salty 

stream called the Rio Salado, 

entering the Rio Grande near 

Alamillo, drains an area containing extensive exposures of 

the saline and gypsif erous Red 

Beds. Nowhere are these 

more prominent than in the 

conspicuous escarpment extending from Mesa Lucero to

Jara Peak. Here tllC

Fossiliferous limestone. l!> ft.

Calcareous shale.

! 10 ft.

Shales and limestone, 100 ft.

Gray prypsiferons shale, 30 ft. 

Yellow and white sandstone, 100 ft.

Reddish gypslf.erous shale, 175 ft. 

Anhydrite and limestone shales, 100 ft.

water conditions prevailing in

FIG. 30. Section of bluff on Rio Salado, 30 miles west southeastern New Mexico 1'Qof Belen, N. Mex. 

peat themselves, and about a

thousand feet of the upper Red Beds are filled with limestone, with gypsif erous shales and massive beds of anhydrite (fig. 30). The lower part 

of the series consists of the quartzites and red shales of the Red division.
98 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

The limestone beds near the top of this escarpment afford numerous 

fossils, a critical study of which should determine the age of the beds.

Region of the Oscuro and San Andreas mountains. The western 

slopes and foothills of the Oscuro and San Andreas mountains expose 

strata analogous to those of the Socorro region, with here and there 

extensive deposits of anhydrite and gypsum. The same conditions also 

prevail east of the Caballo and San Cristobal ranges. The great plain 

known as the Jornado del Muerto is evidently underlain at no great 

depth by deposits of the Red Bed series

The white sands. The white sands constitute one of the largest and 

most remarkable accumulations of gypsum known (see PI. XVTT1). 

This deposit is in Otero County, and is a tract of dunes of nearly pure 

granular gypsum, covering about 350 square miles. The deposit is 

roughly triangular in outline, about 18 miles wide at the southern end, 

and about 35 miles long. It is bounded on the north by a remarkable 

flow of basalt 20 to 40 feet thick, the sound of flowing water beneath 

which can be heard. This water issues from the southern edge of the 

flow as a strong stream, slightly impregnated with salt and alkali. It 

soon sinks into a flat covered with efflorescence of salt and alkalies. 

On the west is the abrupt escarpment of the San Andreas, a granite 

foundation supporting a vast series of sedimentary rocks dipping 

toward the west and embracing a portion of the lower Carboniferous, 

and the lime and quartzite of the Permian. This escarpment is separated from the plain by a profound fault, adjacent to which numerous 

diorite dikes penetrate the stratified series in all directions. Numerous 

and profound cross faults filled with quartz, spar, iron, and copper 

infiltration extend from top to bottom of the series. On the east the 

same conditions prevail 35 miles distant, forming the. escarpment of 

the Sacramentos.

To the south is an open plain broken by the Jicarilla Mountains, and 

to the northeast the massive Sierra Blanca rises over 10,000 feet, to the 

base of which cling the shattered fragments of all the stratified series 

represented in southeastern New Mexico, from the Burlington limestone to the Fox Hills Cretaceous. In an embayment between the 

White and Sacramento mountains, east of the ancient town of Tularosa, 

is a large depressed area covered with broken bluffs presenting the 

eroded edges of the gypsiferous Red Beds or Permian series, which 

undoubtedly forms the floor, of the salt plain.

In this region there have been profound disturbances, and the inference is that the great saline plain has been left undisturbed while the 

corresponding formations have been thrust up on either side.

In the plain itself, a few miles west of Tularosa, is a small intrusive 

cone near which are several warm saline springs which have built up for 

themselves mounds of considerable height. The water from these 

springs soon sinks into the earth, leaving salt flats covered with a
U.'S. GEOLOGICAL SURVEY 

VIEW OF THE WHITE SANDS, NEW ME
HERIUCK.] NEW MEXICO. 99

grayish-white efflorescence. At the northern edge of the white sands 

is a salt lake which has long been a valuable source of salt for the 

ranches in the neighborhood, and near the southeastern corner of the 

sands themselves is another still larger salt lake. Where arroyos cut 

the plain, and in the banks of the salt lakes, are exposures of shale and 

gypsum, which prove that the gypsiferous horizon so prominent on 

either side of the plain can not be far below the surface at any point.

In the salt fiats the ribs of gypsum rise in successive ridges, and the action of the 

elements soon breaks up the exposed crystals into small grains which are carried by 

the winds hither and yon. A short examination shows that these great drifts are 

simply sand dunes collected from the gypsum sand formed, as above stated, on the 

surfaces of the lakes. The salt and alkaline salts are also driven with' the gypsum, 

but on account of their solubility do not remain in the dunes. These dunes lie to 

the southeast of tlie flats, whither they are driven by the prevailing winds, and not 

only cover a large part of the .salines themselves, but form a growing fringe to the 

east and south.«

ZUNI OR WESTERN REGION.

In the vicinity of Gallup and to the north of Fort Wingate the 

Red Beds are well exposed. From the top of the Carboniferous limestones and quartzites to the sandy exposures north along the railroad at Coolidge are numerous disconnected exposures of marls, sands, 

and gypsiferous shales, with beds of more massive gypsum and the 

characteristic ironstone breccias of the Permian. The upper part of 

the lied Beds, consisting of massive variegated sandstones, forms the 

picturesque bluffs and cliffs of the Zuni and Wingate sandstones, corresponding to the Chocolate and Vermilion series described in the 

region of Mesa Gigante. The celebrated Navajo Church is carved 

from the upper members of the series. West of Gallup a similar 

sequence can be observed from the railroad, and the continuity of the 

formation in the Zuni region can easily be traced.

In the valley of the Rito Quemado and in the escarpments of the 

Carrizo Valley fine exposures of the gypsiferous series, may be seen. 

Gypsum is also associated with the salt in the neighborhood of the 

Zuni Salt Lake. 6 East of Rito Quemado gypsiferous marls apparent^ 

form the surface over a large area.

"Herrick, C. L., Geology of the white sands of New Mexico: Bull. Hadley Laboratory, Univ. of New 

Mexico, pp. 12-13.

'> Report of a geological reconnaissance in western Socorro and Valencia counties, N. Mex.: Bull. 

Hadley Laboratory, Univ. of New Mexico, Vol. II, Pt. I.
GYPSUM DEPOSITS IN AEIZONA. 

By WM. P. BLAKE.

CHARACTER AND EXTENT.

There are several known localities in southern Arizona where gypsum 

can be obtained in quantity. The following may be particularly noted:

(1) The Santa Rita Mountains, Pima County, southeast of Tucson.

(2) The low hills along the course of San Pedro River in Cochise 

and Pinal counties.

(3) The Sierrita Mountains south of Tucson.

(4) The foothills of the Santa Catalina Mountains north of Tucson.

(5)' Fort Apache Reservation, in Navajo County.

The Sierrita and Santa Catalina mountain localities are in Pirna 

County. At the latter gypsum has been quarried for economic purposes. In addition, deposits have recently been developed to a limited 

extent in the vicing of Woodruff and Snowflake, but no description 

of the deposits at these places can be given at this time.

The locality in the Santa Rita Mountains is not far from Rosemont, 

and is about 10 miles south of the Southern Pacific Railway. It is on 

the eastern side of the range, a few miles east of the Helvetia copper 

mines, in the midst of a hilly region. The gypsum appears to be 

in beds of great thickness and extent. The croppings form low hills

of considerable magnitude, but they are so much eroded, rounded,

and softened by weathering as to make observation upon the stratification, thickness, and the relations of the gypsum to the inclosing 

rocks difficult. The formations are supposed to be upper members of 

the Carboniferous, Devonian strata having been identified near Rosemont, but they may be found to be Triassic. There has not yet been 

an opportunity for a careful investigation. The few sample specimens 

obtained show a compact granular structure and are somewhat veined 

with dark-colpred streaks. Some specimens resemble alabaster. This 

locality of gypsum was noted in the report to the governor of Arizona 

for the year 1896, and again in the report for 1899, page 127.

The gypsum along San Pedro River occurs in horizontal beds, 

probably of Pliocene or post-Pliocene age. The strata are soft, 

unconsolidated gray sandstones and cla}^s, and appear to be the lower 

members of the same series in which the beds of diatomite and volcanic ash are found. The gypsum is interstratified conformably in 

100
BLAKE.] ARIZONA. 101

comparatively thin layers or seams, rarely more than a few inches in 

thickness. These layers appear to have been formed subsequent to 

the deposition of the strata by crystallization from the infiltration of 

gypseous solutions. The mineral occurs as selenite, and, also, in the 

fibrous form, as satin spar.

The Sierritas locality is in connection with the copper-ore deposits 

of the azurite groups in massive limestone. At this locality the 

gypsum may be regarded as originating from the action of solutions 

of copper sulphate and of iron sulphate upon the lime carbonate, 

resulting in the formation and deposition of copper carbonate, of 

limohite, and of lime sulphate.

The locality north of Tucson, in the foothills at the western end of 

the Santa Catalina Range, has afforded a supply for the production at 

Tucson of plaster of Paris of good quality, which has been used

locally in construction. A considerable quantity of the .product was

used in making the interior decorations o.f the cathedral. The crude 

rock is brought in from the quarry by Mexican teamsters, and little 

is known in regard to the geologic position of the deposit. It is 

probable that it occurs in strata of Triassic age, flanking the ancient 

gneiss of the Catalina Mountains.

Gypsum occurs in the form of selenite in plates of considerable size 

on the Fort Apache Reservation, in Navajo County. It is found at 

three places in such quantity that it is proposed to use it in the construction of houses which are to be built for the Indians.
G-YPSUM DEPOSITS IN UTAH. 

By J. M. BOUTWELL.

CHARACTER AND EXTENT.

The mineral resources of Utah are still so little known that a description of any class of deposits in that State is necessarily incomplete. 

Large deposits of gypsum have been found in several localities in Utah, 

and it is not improbable that others will be discovered in the course of 

the present active economic development.

The more important known deposits occur in the central and southern portions of the State, in Juab County, east of Nephi; in Sanpete 

and Sevier counties, near Salina; in Millard County, at White Mountain, near Fillmore, and in Wayne County in South Wash. They are 

all of the rock-gypsum type, except the one near Fillmore, which is 

in the secondary form of unconsolidated crystalline and granular 

gypsum blown up from desiccated plaj^as into dunes. Deposits are 

also known in Emery County, about 40 miles southeast of Richfield; 

in Kane Count}^ near Kanab; in Grand Countj^, between Grand River 

and the La Sal Mountains; in Sanpete County, near Gunnison; in the 

eastern part of Washington County (?), between Duck Lake and Rockville, and at other places. Recently enormous deposits of gypsum 

have been reported from Iron County, at points so far from lines of 

transportation, however, as to render their exploitation impracticable 

for the present.

In general, a comparison of these deposits with others studied by the 

writer in this country and Canada shows them to be unusually extensive and of excellent quality. In this paper the deposits at Nephi, 

Salina, White Mountain, and South Wash will be briefly described.

ECONOMIC DEVELOPMENT.

Nephi deposits. This immense mass of rock gypsum is located in 

Juab County 1 mile east of Nephi, on the south side of the entrance to 

Salt Creek Valley. (See PL XIX, A.) It has been worked for the last 

fifteen years practically without interruption, and is the only deposit 

in Utah which is now being exploited to any extent. In view of this 

fact a brief visit to this locality was made in December, 1902, and 

(despite a heavy fall of snow which handicapped outdoor work) information was procured which forms the basis of the present statement. a

«For much of the information here presented the writer is indebted to Mr. P. A. Hyde, manager, 

secretary, and treasurer of the Nephi Plaster Company, and to Mr. James Jackson, superintendent 

in charge of both quarry and mill, who courteously afforded every facility for studying the occurrence and exploration of this deposit and furnished important information,

102
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. XIX

A. ROCK-GYPSUM DEPOSIT 1 MILE EAST OF NEPHI, UTAH.

S. BED OF GYPSUM ON MESA 15 MILES NORTH OF KING CITY, MONTEREY

COUNTY, CAL.
BOUTWELL.] UTAH. 103

This deposit was known before the town of Nephi was settled, and 

has probably been known to the whites for nearly eighty years. About 

thirty-five years ago a claim 600 by 1,500 feet in dimensions was 

formally located, and in 1882 this was patented by John Hague and 

others under the name of the Juab Plaster and Mining Claim. After 

small intermittent shipments to Salt Lake City in 1887, under the 

management of Messrs. Hyde, Hague and Whitmore, rock gypsum 

was quarried and burned in sorghum, pans for local consumption. 

During the following year, encouraged by the rapidly increasing 

demand, these persons incorporated their company and erected the 

nucleus of the present efficient plant.

The rock is now obtained by blasting from an extensive open cut, 

and is trammed by gravity to the works. The present plant, which 

is the product of repeated enlargement, though riot extensive, is very 

complete. It includes (1) a mill which is fitted with 1 nipper, steel

grinder, round buhrs, 3 chain elevators, 2 two-flue 8-foot calcining 

kettles, a mixing plant, etc.; (2) a complete cooper shop, and (3) storehouse. Ample power is supplied by a turbine driven by water taken 

from Salt Creek and conducted by a sidehill ditch to a point high 

enough above the mill to afford sufficient fall.

The output from this plant includes dental, casting, finishing, land, 

and hard plaster, each, appropriately prepared for its special uses. A 

large and increasing demand is supplied throughout the Great Basin 

region, and shipments are made as far as Grand Junction on the east 

and Los Angeles and Hawaii on the south and west and Victoria on 

the north.

Other bodies of rock gypsum outcrop at several localities higher 

up in Salt Creek Valley. Some of these have been worked on a small 

scale, but owing to their less suitable location and poorer quality they 

have been abandoned.

jSalina deposits. a These deposits have been worked within a few 

years to some extent for general commercial uses, but chiefly for local 

needs. Rock gypsum of good grade occurs in a bed of considerable 

thickness, and was recently quarried and ground in a small mill. At 

present, however, active operations have been suspended.

White Mountain deposits. b This vast deposit has been worked only 

on a small scale and for local needs. Of the thre.e types of gypsum 

which comprise it, gypsiferous' clay, gypsum sand, and mounds of 

loose small crystals, the last probably offers the greatest commercial 

possibilities. This unconsolidated crystalline gypsum, probably of a

: 

a Information given in this sketch regarding these deposits has been gathered from various sources,

including Mr. James Jackson, superintendent of the Nephi Plaster Company, 

bStatements in this paper about these deposits are based upon personal communications to the

writer by Mr. G. K. Gilbert and descriptions which he has published in his work on Lake BonneVille, Mon. U. S. Geol. Survey, vol. 1, pp. 222-223, and PI. XXXV.
104 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

LEGEND

g Gypsum

gs Gypsum sand

gc Gypsum, clay

p ffhyolite

ct Calcareous tufa

high degree of purity, lies upon the slopes of elevations composed of 

volcanic rocks, and forms mounds or dunes. "Perhaps no gypsum 

deposit in the world is so easily exploited as this. It needs merely to 

be shoveled into wagons and hauled away. Mr. Russell estimates that 

the dunes contain about 450,000 tons, and a much larger amount can 

be obtained from the playa. The depth of the playa deposit was not 

ascertained. " a

/South Wash deposits. Occurrences of rock gypsum observed in 

Wayne and Garfield counties by Mr. G. K. Gilbert in 1871 (then geologist on the Wheeler Geographical Surve}r) are described by him as so

extensive that one could 

walk in one direction for 

about 2 miles without 

stepping off from gypsum. So far as known, 

these extensive deposits 

of rock gypsum and gypsum sand have never 

been utilized for commercial purposes. The 

only known use made of 

them was for exhibition 

purposes, when, under 

the auspices of the Deseret Museum, of Salt Lake 

City, 20 tons of the crystalline variet}r, selenite, 

was shipped from the 

South Wash deposit to 

Salt Lake City. Professor Talmage states 

that "the huge geodes 

of selenite or crystallized 

gypsum on the deserts of Wayne and Garfield counties, and the associated gypsum of other forms, such as plaster-stone and gypsiferous 

sand, will doubtless prove of value, but, chiefly owing to the inaccessible nature of the region, deposits have not been touched in the way 

of commercial development."

DESCRIPTIONS OF LOCALITIES.

JVepM deposit. This is the largest thoroughly known deposit of 

rock gypsum in Utah, and one of the largest in the world. It forms 

the entire mass of a prominent spur at the entrance to Salt Creek 

Valley, and outcrops from the level of the creek up the slope in a southFIG. 31. Map showing extent of White Mountain, Utah, gypsum deposit.

"Gilbert, G. K., Lake Bonneville, Mon. U. S. Geol. Survey, vol. 1, p. 223.
HOUTWELL.1 UTAH. 105

easterly direction in the form of a vertical bed or lens (see PL XIX). 

The exposed portions of this body are from 275 to 300 feet in thickness, 500 feet in height along the bedding, and at least 700 feet in 

length along the strike. The length depends upon whether the deposit 

thins oat along the strike is faulted or continues unbroken. Owing to 

a thick blanket of sn6w which covered the upper portion of the gypsum croppings to a depth of 2£ to 3 feet at time of visit, this could 

not be observed. The croppings-are reported, however, to have been 

traced southeastward for several hundred feet to the main divide.

Although the total thickness of the deposit is made up of gypsum, 

the character of the rock varies somewhat in different beds. A general section from foot to hanging wall includes the following:

General section at Nephi, Utah.

Feet.

Interbedded shale and gypsum, marl, and gypsum dirt........................ 30

Hock gypsum, "first-class"...... ..-.........'................................ 65

Rock gypsum, fractured, occasional bands of disseminated calcareous particles, etc. 75 

Bock gypsum, "first-class " ..1............................................... 55

Gypsum and shale, transition to shale ........................................ 50

The second member affords all of the present output; the third, 

though g3^psum of good quality and easily extracted, owing to its 

 fractured state, is not quite so pure, while the fourth is of excellent 

grade and will probably be operated in conjunction with the second 

by the open-cut method in the near future.

The first-class rock is massive, dense, lusterless, and light grayish 

brown. The chief variations are a mottled, whiter, harder facies, 

which occurs at the top of the main bed exploited (No. 2) and "shaly" 

bands. The bands are zones, in which small, brown, angular fragments are included in white and brown rock g}7 psum. These fragments prove on analysis to be more calcareous than the balance of the 

rock.

Reliable analyses of gypsum are rare, so that there remains much 

to be learned regarding the desirable qualities in its composition. In 

view of this and of the significant facts developed, two analyses are 

here given, No. 1 of a sample of first-class rock gypsum from the 

second member, No. 2 of "shaly" portions in waste or rejected 

gypsum rock from the third member.

Bull. 223 04 8
106 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. '2'2'6.

Quantitative partial analyses of gypsum, from Nephi, Utah. 

[ Analyst, Dr. E. T. Alien.]

No. 1.

CaO ............................ 36.29

MgO .-.-----.-.-------.--..---. trace.

H,0............................ 15.88

SO,............................. 48.14

CO,.......................'.....: .65

Cl ----.---------------------.... trace.

99.96

No. 2.

Insoluble ....................... 0. 45

CaO ............................ 38. 46

MgO'..........'............'...... .24

K2 0 ............................ .19

Na2 0 ........................... .07

H2 0..... ...............:...... 12.69

S03 . ......... ....;.............. 39.53

C02 ............................ 7.73

Cl.... ................... ....... .04

99.54

From these results Doctor Alien determines that the first sample is 

made up of 76 per cent gypsum, 22.5 per cent anhydrite, and 1.5 per 

cent calcium carbonate (limestone ?); and that the second is composed 

of 60.5 per cent gypsum, 22 per cent anhydrite, IT per cent calcium 

carbonate (limestone ?), and 0.5 per cent magnesium carbonate (dolo-, 

mite ?).

Perhaps the most important feature brought out by these results is. 

that the first-class rock, as well as the "waste rock," includes between 

22 and 23 per cent of anhydrite. The significance of this fact lies in 

the practical influence of the anhydrous material on the action of the 

combined product; for although when gypsum is calcined the largest 

portion of water is driven off, it is generally regarded as essential to 

its suitability for plaster that some of its water be left. "When 

it is heated to 100-120° C. it gives up three-fourths of its Svater very 

quickly,' but it requires a temperature of from 200-250° to expel the 

remainder. * * * If gypsum has been heated to a little over 200°, 

thus being deprived of all of its water, it becomes dead burnt, and takes 

up water very slowly and without hardening." 0

It would seem, therefore, that in so far as natural anhydrous calcium 

sulphate (anhydrite) is like artificially dehydrated gypsum in actual 

practice, the presence of anlrydrite would at least retard "setting." 

In the manufacture of patent cements, however, heating to 600-700° 

F., when carried on in conjunction with the addition of sulphuric acid, 

borax, and cream of tartar, etc., is stated to give a product, which, 

after setting very slowly, becomes exceeding^ firm and hard. 6 It is 

probable that anhydrite occurs in a large percentage of the gypsum 

deposits, so that further reliable analyses of other gypsums which 

made plaster of good setting quality are much to be desired.

The presence of calcium carbonate (limestone) to the extent of 17 

per cent in the rock which is sorted out for rejection may be advan-

« Thorp, T. E., Dictionary of Applied Chemistry, vol. 1, p. 406. 

6 Wilder, F.'A., Iowa Geol. Survey, vol. 12, p. 157.
 BOUTWELL.] UTAH. 107

tageous for special uses. In the preparation of certain hydraulic 

cements limestone is considered a valuable constituent. The significance of the content of potassium, magnesium, and sodium in connection with the origin of these deposits is considered hereafter.

Several other deposits of value are known in the Salt Creek Valley 

east of the main body, the most important of which is on the north 

side of the creek, about one-half mile east of the Nephi plaster mill. 

They include rock gypsum of good grade. In many localities the}7 

would be exploited, but they are so near the great body at the mouth 

of the valley that they are not worked.

Salina deposits. -On the General Land Office map these deposits 

are shown as extending in a northeast-southwest belt from Maytield, in 

the southern portion of San Pete County, to Salina, in the northern 

part of Sevier County, a distance of about 18 miles. The}' were not 

visited by the writer, but are known upon reliable authority to be of 

the rock-gypsum type.

White Mountain deposits. In Millard County, about 8 miles west 

of Fillmore, occur very extensive and valuable secondary deposits of 

gypsum. They include deposits of gypsiferous clay, covering an oval 

area approximately 3 by 5 miles in extent; two areas of gypsiferous 

sand, one one-half of a mile long and one-third of a mile wide, the 

other an irregular area approximately one-half a mile square, and an 

elongated area of gypsum about 2 miles long and one-half mile wide. 

(See fig. 31.) The gypsum contained in each is believed to have been 

transported by streams from its original position in the mountains on 

the east and redeposited with detritus in the White Mountain playa. It 

is in the form of minute crystals. To a considerable extent these have 

been freed from inclosing sediments by desiccation, reconcentrated by 

the wind, and collected into dunes of pure gypsum.

South Wash deposits. This deposit was not visited by the writer. 

The present statements regarding it are from an illustrated description by Prof. J. E. Talinage, of the Utah State School of Mines. "

* Here and there along the gorges are outcrops of gypsum varying in degrees of 

purity, and seams of this material cut through the country rock in all directions. In 

places veins of satin spar, as thin as a sheet of note paper, or even an inch in thickness, can be traced for many hundreds of yards upon the surface of the ground in 

uninterrupted course, except for .intersecting planes of the same material. On the 

walls of the ravines and canyons places are seen where spar veins cross and recross 

each other with bewildering profusion. * * * Gypsum in all varieties may be 

found within a short radius. Fibrous and scaly laminae, plaster stone or rock gypsum in masses, lumps of pure alabaster, and fragments of selenite crystals are scattered along the washes and strewn upon the bench lands. * * * 

The crystals occur in a cave, and this is inclosed by a thick shell forming a mound.

* * * This selenite mass seems to have been left exposed by the weathering of 

loosened friable sand and clay, of which the hill whereon the mound is situated is 

composed. * * * Prisms of perfect form and varying in length from 1 to 5 feet

aScience, vol. 21, pp. 85-87.
108 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

and in weight from 10 to 100 pounds are of frequent occurrence. One of the most 

regular yet taken out is 4 feet long,and the "widest faces are 6 inches across. Cleaved 

slabs are obtainable 6 feet in length and 2£ feet in breadth. One of the longest perfect prisms yet obtained extends 51 inches, and from one of its faces 19 smaller 

crystals sprout. Twins are common, as are also compound terminations of very 

complicated structure.«

Specimens from this localit}^ are on exhibition in the National 

Museum and other institutions.

Since studying this occurrence, ProfessorTalmage has found a half 

dozen more geodes, and "has no doubt that the entire deposit is 

gypsif erous."

GEOLOGIC RELATIONS.

' " W&phi'"deposits. The geologic structure of this region is exceedingly complicated; and only its broadest characteristics can be stated 

now. The Nebo massif; to the'north, composed of Paleozoic rocks, 

appears to have been elevated above the tract of Jurassic and Tertiary 

rocks to the south and east by fault ; along the northeast-southwest 

zone. The tract on the southeast siua of this possible fracture zone 

includes a considerable thickness of olive and gray calcareous shales, 

buff limestone, black piaper shales with massive interbedded members, 

gray sandstone, reddish conglomerate, and a heavy series of grayishbrown sandstone. The general eastward dip is frequently lost in 

excessively folded and tilted structures. The geologists of the 

Wheeler Survey were of the opinion that an unconformity between 

the Tertiary and Paleozoic appears in this valley.

The area in the immediate vicinity of the main g}7psurn deposit lies 

on the southeast side of the possible zone of fracture, and the beds are 

extremely deformed. On the north side of the mouth of Salt Creek 

Valley gray and black shales stand vertical, and strike northeast; 

farther east they swing into east and southeast strikes and dip to the

north, thus forming the nose of an anticline which plunges steeply 

northward. The gypsurn bed lies on the south side in a series of buff 

limestones and gray and buff calcareous shales. The strike of this 

series is northwest-southeast, and the general dip is vertical or steep to 

the southwest, except where local variations occur adjacent to fissures 

or closely appressed folds. The gypsum body stands nearly vertical, 

dipping locally 85° SW. between shale walls, and strikes southeasterly. 

Owing to the snow which covered the ground at the time of visit, 

neither the upper nor lower contact nor either limit along the strike 

was observed, so the precise nature of the occurrence can not be positively stated. It appears, however, to be in the form of a bed deposited 

contemporaneously with inclosing sediments, and it is probably either 

a thick lens which pitches rapidly along the strike or a bed which 

has been terminated in either direction along the strike by faulting.

«jldem, p. 8G; also see description by Moses, Alfred J., One of the gypsum crystals from the cave at 

South Wash, Wayne County, Utah; Science, vol. 21, pp. 230-231.
BOTJTWELL.] UTAH. 109

Although the study of the region was too hasty to obtain sufficient 

data for a complete explanation of the origin of the deposit, general 

observations, together with facts brought out by the analyses, afford 

accordant evidence for an opinion. The bedded structure of the 

gypsum, the agreement of this bedding with that of the country rock, 

the interbedding of the wall rock and gypsum, and the occurrence in 

the same series in this neighborhood of rock salt, common salt, and 

gypsum of various degrees of impurity tend to indicate a sedimentary 

origin. The presence of about 1Y per cent calcium carbonate, one-half 

of 1 per cent of magnesian carbonate, and minor amounts of potassium 

and sodium salts afford additional basis for the belief that this gypsum 

.is the product of deposition from surface water bodies, such as inland 

lakes, lagoons, or bayous.

The geologic date of this deposition can not be settled until further 

paleontologic evidence has been obtained. The rocks of the region 

are indicated on the geologic map of the Wheeler Survey as Jurassic, 

and in the report it is stated that "The Jurassic rocks are everywhere 

found to be very gypsiferous, and in some places good workable beds 

of gypsum are seen. One of these beds occurs at Salt Creek, near 

Nephi.«

Salina deposits. The country rock in which the principal deposits 

occur is reported to be made up of dark-red shales and sandstones. 

The general area occupied by this belt of gypsum was mapped by the 

geologists of the Wheeler Survey as Jurassic and Tertiary,'' and mention of "some fine selenite crystals from the Salt Mountains just south 

of Salina," c where Jurassic was mapped, suggests the probability that 

this deposit was considered of Jurassic age.

White Mountain deposits. High-lying beaches and related shore 

phenomena indicate that at an early geologic period the greater 

portion of Utah was submerged beneath the waters -of an extensive 

inland sea. rf When the level of this lake was lowered by drainage 

over its rim and by desiccation its extent steadily decreased and the 

bottom became exposed. Then the great Bonneville basin became 

subdivided into a number of smaller separate basins. In the lowest 

depressions of these basins lie either the existing lakes or playas.

In the southeastern angle of the Sevier Desert, there is a tract partially partitioned 

from the general plain by a series of coulees of basaltic lava Qxtravasated during the 

Bonneville epoch. This contains several playas, marking localities where the 

drainage is checked but not completely imprisoned. The highest and most southerly 

of these differs from all the others in that its material is gypsum. It is probable 

that the deposit is independent of any special chemical reaction, and is due simply 

to discharge by evaporation of a mineral dissolved from the rocks. The streams 

whose waters occasionally flood the playa rise amongst strata of Jurassic and Triassic

uHowell, E. E., U. S. Geog. Surveys VV. 100th Her., vol. 3, p. 264. 

6U. S. Geog. Surveys W. 100th Mer., atlas sheets 50 and 59. 

cHowell, E. E., U. S. Geog. Surveys W. 100th Mer., vol. 3, p. 204. 

d Gilbert, G. K., Lake Bonneville: Mon. U. S. Geol. Survey, vol. 1,1890.
110 GYPSUM DEPOSITS IN THE UNITED STATES. rBULL.223.

age, and such strata in the neighboring range are known to be highly gypsiferous. 

The heads of the streams were not examined. It was ascertained by digging in the 

'playathata portion of the deposit is amorphous and another portion crystalline. 

One phase of the precipitation results in the formation of small free crystals, which 

the wind sweeps from the surface of the playa and gathers into dunes. The dunes 

do not travel to a great distance, but are arrested by a low rhyolitic butte near by, 

to which they have given the name of White Mountain «.

South Wash deposits. The precise geologic -occurrence and age of 

the country rock of the South Wash gypsum is uncertain. Geologists 

of the Wheeler survey mapped this region as Triassic, Jurassic, and 

Cretaceous, with overlying trachyte, rhyolite, and Quaternary 

deposits. Professor Talmage states that "the formation in the 

neighborhood of the deposit in question is mostly sandstone argillite 

with a top dressing of erratic bowlders of lava. * * * Ripple marks 

in great distinctness are frequent in the sandstone of this region, and 

other evidences of lake formation are common." 6 Detailed geologic 

field work will be required before these points can be settled.

. a Ibid., p. 223. b Science, vol. 21, p. 85.
Q-YPSTJM DEPOSITS IN OREGON. 

By WALDEMAB, LINDGREN.

CHARACTER AND EXTENT.

The only deposit of gypsum known to occur in Oregon is on the 

eastern border of the State, near the middle point of the boundary line, 

on a ridge dividing Burnt Kiver and Snake River. It consists of beds 

of rock gypsum, which have a limited geographic extent. Smaller 

areas, which are continuations of these deposits, are reported to occur 

over the border, in Idaho. The. material is of good quality and is well 

suited for economic uses. The gypsum is in part white and crystalline; in part, however, it contains thin strata and films of greenish 

chloritic mineral.

ECONOMIC DEVELOPMENT.

The gypsum beds have been known for thirty^ years, but have been 

developed only recently. In 1896 a mill was erected which was 

destroyed by fire the same year. The plant, however, has been rebuilt 

and is now in operation. It is situated on Burnt Kiver, 4 miles below 

Huntington, at a station called Lime, on the Oregon Railroad and Navigation Company's railroad. From this place a winding road ascends 

a ridge to a point about 1,500 feet above the level of the river. The 

gypsum occurs about 200 feet below the summit of the ridge, on 

the slope facing Snake River. On account of the northwestward 

dip the development has been undertaken by means of tunnels. The 

elevation of the lower opening is approximately 3,900 feet above sea 

level. At this point a tunnel 1YO feet long, connecting with an upraise 

100 feet long, exposes gypsum rock of good quality 20 feet thick. 

The conditions for exploitation are excellent.

GEOLOGIC RELATIONS.

The lower portion of the ridge between Burnt River and Snake 

River is occupied by a series of old lavas, largely rhyolitic in character. Above these rests a sedimentary series, in which the gypsum is 

interstratiiied. The mineral-occurs as elongated lenses, which are in 

places from 10 to 40 feet thick. The bed exploited rests on slates and 

limestones. It is covered by a thick series of shales, which contain a 

few intercalated strata of volcanic tuffs. Thick beds of limestones also 

occur in the series. The dip of the beds is low, to the northwest.

The period to which the gypsum beds belong is probably early 

Mesozoic. This is judged from the geologic relations of sedimentary 

beds of the region, but the evidence is not wholly clear.

 ' 111
GYPSUM DEPOSITS IN NEVADA. 

By GEORGE D. LOUDERBACK.

CHARACTER AND EXTENT.

Gypsum has been found at a number of places in Nevada, but as 

systematic exploration of the State for it has never been made its 

exact distribution and extent can not be given..

The best-known deposits are in northwestern Nevada, at Lovelocks 

and Moundhouse, where gypsum has been developed commercially. 

These deposits occur in rocks of Mesozoic (probably Triassic) age. 

Beds of gypsum have also been reported from the Star Peak, Sonoma, 

and other ranges, and it is reasonable to believe that careful search 

would disclose many localities in northwestern Nevada.

The deposits which have been worked are generally of massive, 

compact, or granular rock gypsum, commonly white, more rarely yellowish in color. They are almost pure,, and make a fine grade of plaster, 

as is shown by analyses and by the character of the manufactured 

product.

In the two localities studied in the field the gypsum is inclosed in 

white limestone, in series which, in addition, consist of quartzites and 

slates. With them are associated gypsiferous limestones and slates. 

In the slate the gypsum generally occurs in the form of selenite, sometimes in large crystals several inches across. Gypsum dirt, formed 

from the rock gypsum by secondary action, lying on the surface of 

the bed or on the lower hill slopes, or in gullies or other depressions, 

accompanies these deposits, and may prove to be of economic value.

Gypsum also occurs in the extreme southern part of the State, in an 

area on the border of the Grand Canyon province. Within that region 

some of the Mesozoic, especially Jurassic, sediments have long been 

known as gypsum bearing. These outcrop in the Spring Mountains 

and other ranges to the south. The deposits are mainly rock gypsum, 

having a rather compact structure, and are interstratified with shales 

and sands. Massive beds of rock salt occur in the same country, possibly in the same series.

Gypsum is found also in lenticular beds in the Carboniferous strata 

of the Spring Mountain Range, associated with limestone. The section, 

according to Gilbert, is:

Section of Carboniferous strata in the Spring Mountain range.

Feet.

Bedded, fine-grained to saccbaroidal limestone, gray and cream colored, separated by shaly layers so as to weather in steps, fossiliferous ........*....... 500

Massive gypsum, white and red, in lenticular masses ........................ 0-70

Gray, massive, cherty limestone, fossiliferous ............................... 475

112
LOUDK It BACK.] NEVADA. 118

The eastern, central, and southwestern parts of the State make up 

the great Paleozoic (and Archean) bed-rock province. No deposits of 

sedimentary gypsum have, to my knowledge, ever been reported from 

this region. This mineral has not been particularly sought for, and 

future prospecting may bring it to light.

Lake beds of Tertiary or later.age are widely distributed in Nevada. 

In some of these gypsum beds occur, associated with friable sands, 

clays and calcareous layers. Almost pure beds several feet thick are 

known. The gypsum occurs both as white granular layers and as 

selenite.

The gypsum may be formed by the action of sulphuric acid on limebearing rocks. In this process the sulphuric acid is derived from the 

oxidation of pyrite or other sulphides. Small bodies of g}^psum having 

this origin are not uncommon, as might be expected from the abundant.

mineralization in the Nevada ranges, and the great depth of the zone 

of weathering in the Great Basin. Where the country rock is limestone, as is frequently the case throughout eastern and central Nevada 

(the Paleozoic province),, the resulting gypsum is more or less granular, like ordinary rock gypsum, and in small exposures it is hard to 

determine its origin by its general appearance. But where the country 

rock is a lime-bearing volcanic rock, such as andesite, the resulting 

gypsum is in the form of selenite crystals, strewn, sometimes very 

abundantly, through the residual brown, yellow, red, or even white 

clayey earth. Such deposits are especially common in western Nevada, 

but are apt to be top irregular and uncertain for profitable working.

It may be noted that special attention has not until very recently 

been directed to the gypsum deposits of the State, since the local 

demand has been very small and the difficulty of solving the transportation problem has interfered with exportation to other States.

ECONOMIC DEVELOPMENT.

The gypsum deposits in southern Nevada have not been developed. 

They are many miles from any railway or large towns. They are, 

however, in the region that is to be traversed by the railroad, now 

building, which will connect Salt Lake and Los Angeles, and may 

become of economic importance within a few years.

The gypsum which has thus far been exploited is located in the 

northwestern part of the State. One of the deposits lies at the western 

base of the Humboldt Mountains, 4i miles east from Lovelocks, a 

station on the Central Pacific Railroad. Considerable work was done 

there in 1891 to 1893, and elevated bins filled with gypsum are still 

standing. During the period of financial depression (1893) the work 

was abandoned. Recently a local company was organized to work the 

deposit. Many prospect holes have been sunk and a new cut has been
114 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

opened. Negotiations are now in progress with a California company 

to place the product on the California market.

A second deposit is in the Virginia Mountains, li miles west of 

Moundhouse Junction. The g}rpsum is at present hauled to Empire, 

where it is manufactured. . This localit}^ is about halfwa}^ between 

Carson and Virginia, on the Virginia and Truckee .Railroad. The 

exposure is favorable for operating, and the gypsum is obtained by 

quarrying.

120 119°

39 39

120 118°

FIG. 32. Sketch map of a portion of Nevada showing gypsum deposits which have been developed.

The Lovelocks deposit is interstratified in the older sedimentary 

series, and strikes roughly parallel to the trend of the range. At its 

broadest outcrop it covers the hill slopes for some 1,200 feet, and forms 

a striking exposure. On account of its light color and its uniform furrowing by rain erosion it is a distinctive landmark, visible for many 

miles, especially in the afternoon light.
LOTJDEEBACK.] NEVADA. 115

The rock gypsum taken out some feet below the surface is a pure 

white or grayish white granular mass, almost free from foreign 

substances.

At or near the surface the gypsum occurs as a white, earthy, or friable porous mass, which, washing'.gradually down the hill slope, masks 

the details of the structure. Careful examination shows that in the 

midst of the deposit the mass is almost entirely gypsum, with here and 

there thin strata of white limestone. Above and below the mai n mass of 

gypsum the limestones become more numerous and then preponderate, 

and finally pass into pure white, granular limestone. At one point in 

the gypsum series a rather thick limestone bed is accompanied by a 

few feet of quartzite.

At the point of broadest exposure the gypsum is folded into an anticline, but as the floor is not exposed it looks like one great bed.

Just above the white limestone roof .occurs a black or dark-gray

limestone, intersected by many small fractures filled with calcite veinlets. The axis of the anticline above alluded to strikes about 4 or 5 

degrees east of north and a quarter of a mile.northeast of the bins it 

pitches down below the surface. A fault, with a horizontal thrust of 

about 300 yards to the northwest, has displaced the gypsum lying 

south of the bins. Several faults with vertical displacement are seen 

to break across the fold at right angles to its axis. To the south the 

axis of the main anticline pitches down, and the gypsum does not 

extend a great distance.

About two-thirds of a mile north of the bins the gypsum is brought 

to the surface by faulting. It occurs in a flat syncline, pitches gently 

toward the north, and is overlain by the characteristic black limestone. 

Its most southern outcrop occurs on the steep side of a prominent 

hill, whence it runs northward in two arms toward the Humboldt 

Valley, and there disappears under the valley deposits. The west arm 

reaches the valle}^ at about a half mile and the east arm at about a 

mile from the top of the hill.

In the open cut just south of the bins, which is about 12 yards deep 

and over 20 yards wide, a good exposure is obtained which brings out 

beautifully the complicated structure of the deposit (PL XX).

The gypsum in the locality of the syncline is 130 feet thick, including perhaps 10 or 20 feet of intercalated limestone. At the other 

outcrops its measurement is very difficult, but it'is probably nowhere 

over 200 feet thick. .

The Moundhouse gypsum deposit lies on the east flank of the Virginia Mountains in the form of a thick bed, striking about 12 degrees 

west of north and tilted at a high angle generally practically vertical. In its unweathered condition the gypsum forms a milk-Avhite, 

granular mass, looking much, like marble. Roof and floor are of 

pale brownish-yellow, granular limestone, frequently brecciated and
116 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL.223.

fractured, and recemented by banded, columnar aggregates of calcite. 

The greatest width of the exposure of gypsum is 130 yards, and, since 

faulting can not be determined and the dip is about vertical, this gives 

an estimate of the thickness of the bed.

The main deposit, which is cut off abruptly by diorite on the south 

side, runs north about 270 yards, with an average width of about a 

hundred yards, and then rapidly narrows to a thin band that soon 

gives out. The gypsum and its inclosing limestone are entirely surrounded by diorite, which is the chief country rock of the vicinity. 

The diorite is overlain at one point by a small area of andesite, which 

covers the limestone-diorite contact on the east side of the gypsum. 

A little farther northeast the diorite is covered by a small area of 

rhyolite. Limestone similar to the wall rock of the gypsum deposit 

outcrops at intervals in the diorite north of the main deposit, and is 

associated, at least at one point half a mile distant, with a comparatively 

thin bed of gypsum.

The gypsum is eroded more rapidly than the accompanying rock, 

and therefore a considerable depression had formed before quarrying 

was begun. Much of the material has been washed down an eastwardtrending gully that drains the area and has formed, alone or with 

earthy detritus, gypsiferous alluvial deposits.

. Thus far no layers of sandstone, limestone, or any other rocks have 

been found breaking the continuity of the main gypsum bed. The 

gypsum is rarely stained with iron, and, as before stated, its color is 

generally a nearly pure white. Several analyses show it to be of 

excellent qualuVy, the chief impurity being CaCO3 . Some very subordinate bunches of pyrite were found in the upper west quarry.

The gypsum is apparently an original member of the stratigraphic

series to which the limestones belong. On careful observation one

may see the lamination of the bed. This consists not of structural 

variations, but in a very faint color banding, not noticeable in hand 

specimens, the alternating layers varying from gray to white. There 

appears to be no distortion or crumpling of the bed, although in places 

along the wall it is brecciated. Cracks extending from the surface 

into the gypsum, have allowed the percolating waters to carry down 

fine sand, which is found in the quarries in very thin, more or less 

vertical layers, or in horizontal^ extended bunches. Percolating 

waters have also in places hollowed out small caves, a foot or so across, 

which have smooth interior surfaces. <m

GEOLOGIC RELATIONS.

The Humboldt Mountains (the West Humboldt Range of the Fortieth Parallel Survey) form a range near the middle of northwestern 

Nevada, 80 or 90 miles east of the California-Nevada boundary line, 

and extend about 72 miles. They lie just southeast of the Humboldt
U. 8. GEOLOGICAL SURVI 

EXPOSURE OF GYPSUM AND LIMESTONE IN OPEN CUT AT LOVELOCKS, NEV., TH
UHJBERBACK.] NEVADA. 117

River and the line of the Central Pacific Railroad, which parallels 

 them throughout their whole extent. These mountains are sharply 

separated into two groups by a transverse valley or pass, determined 

by faulting. The southern or Humboldt Lake group, in which the 

Lovelocks gypsum deposit lies, runs northeast and southwest for 

about 42 miles, with a maximum height of approximately 6,TOO feet, 

or 2,700 feet above the Humboldt Valley. It is by far the lower of 

the two. groups.

' The rocks of this range may be divided into the bed rock and the 

super jacent series. The former consists of Triassic and Jurassic sediments slates, limestones, and quartzites somewhat metamorphosed, 

folded, and faulted. These are overlain unconformably by the superjacent series, which is made up of Cenozoic volcanics rhyolites, tuffs, and 

basalts which were affected by simple dislocation and tilting without 

folding at the time of the final upheaval of the range. This upheaval

was in the nature of a tilting of the range as a mass, the west side 

being elevated along a fault line, the east side remaining comparatively 

depressed. Toward the north and more elevated end of the Humboldt 

Lake group the sedimentary series predominates; toward the south 

and more depressed end the volcanics, especially the rt^olites, are 

largely in excess.

The writer did not find any fossils in the vicinity of the gypsum; 

and their presence would not be expected, considering the conditions 

under which gypsum forms. The gypsum deposit, however, underlies a series of slates, which may be traced to Muttlebeny Canyon, 

about two miles south, and these slates underlie shaly limestone beds, 

in which Prof. J. P. Smith, of Stanford University, has collected 

upper Triassic fossils. We may accordingly look upon the gypsum 

as being of Upper or Middle Triassic age. The Lower Triassic has 

not yet been recognized in the Humboldt Mountains.

The Virginia range, in which the Moundhouse deposit lies, runs 

north and south, approximately parallel to and from 8 to 16 miles 

east of the California-Nevada boundary line. Throughout the greater 

part of its extent i. e., from its north end, opposite Pyramid Lake, 

for about 70 miles southward it is a mass of Cenozoic volcanics. 

The elevation of the range in late Cenozoic time and the accompanying erosion were not sufficient to bring the older rocks the bed-rock 

series to the surface, even in the deep cai^on" of Truckee River, 

which cuts completely across the range in the vicinity of Reno. A 

short distance south of Virginia City, however, the older rocks may 

v»f. seen, though still largely covered by lava flows and ash beds. This 

bed-rock series consists mainly of granitoid rocks, containing here and 

there larger or smaller disconnected included masses of the older 

strata, now considerably metamorphosed, and appearing as granular 

limestone, quartzite, or schist.
118 GYPSUM DEPOSITS IN THE UNITED STATES. [BUit.223.

The age of the gypsum deposit may be inferred from general stratigraphic considerations. It belongs to the series of older rocks that 

were folded and intruded at the time of the post-Jurassic upheaval of 

the mountains, and lies unconforinably below the Tertiary lavas. It 

is in a geologic province in which no pre-Triassic sedimentary rocks 

have been found. It is, therefore, probably Triassic or Jurassic, and 

the occurrence of other similar deposits in the same geologic province' 

in the Triassic, notably the Lovelocks deposit above described, and 

the absence of such deposits from the known Jurassic of this region, 

make a strong case for the Triassic age of the Moundhouse beds. The 

nearest known fossiliferous strata are the limestones near Dayton, 

which is 6 miles, in an air line, east of the gypsum deposit. These 

yield marine forms of the Triassic period.
G-YP8UM DEPOSITS IN CALIFORNIA, 

By H. W. FAIRBANKS.

CHARACTER AND EXTENT.

The gypsum deposits of California are widely distributed over those 

portions of the State underlain by the younger geological formations. 

The mineral is found through nearly all portions of the Coast Ranges, 

particularly south of San Francisco Bay, in the foothills of the Great 

Valley, and in the valle\^s of southern California (see PL XXI). There 

are no instances known of its occurrence in commercial quantities in the 

older metainorphic rocks, as is the case with some of the deposits of 

Nevada.

Although so generally distributed over the State, beds of gypsum 

of sufficient size and purity to make them ol value are comparatively 

rare. The deposits occur as interbedded strata, as veins, and in one 

instance as a layer or crust upon the surface of clay beds.

Nearly all the deposits are associated with clays which are gypsiferous. The interstra'tified deposits are of contemporaneous age, but 

the veins are later than the rocks with which they are associated, and 

are due to the concentration of the gypsum by percolating waters 

gathering it in solution from the clays or shales through which it 

was originally disseminated.

The interstratified beds, while of greater extent, are usually of 

poorer quality than the veins, and many deposits have been opened 

which contain such a percentage of impurities as to make them only 

locally available as fertilizer. In physical character.'this gypsum is 

softer than that in the veins, and is rarely crystalline.

The Tertiary clays all over California contain small amounts of gypsum. The gypsum is in the form of small nodules and sheets of clear 

cleavable selenite, which in many localities are scattered thickly over 

the surface. In the more consolidated clays and shales the gypsum 

forms little veins varying in thickness from that of a knife blade to an 

inch or more.

Some of the sinks of the Great Basin in southeastern California 

contain deposits of gypsum about which little is known. These are 

associated Avith salt beds and appear to have resulted from precipitation in lakes as the waters evaporated.

The purest gypsum is found in secondary deposits, and when they 

are of sufficient size and near lines of transportation they become of . value in the manufacture of plaster of Paris. The gypsum in veins is 

usually white or light gray, and in some places becomes clear enough 

to be termed alabaster.

119
120 GYPSUM DEPOSITS IN THE UNITED STATES. [nuLL.223. 

ECONOMIC DEVELOPMENT.

From an economic standpoint the development of the gypsum 

industry of California is in its infancy. Comparatively little gypsum 

is mined for manufacture into plaster of Paris, owing largely to cheap 

transportation from points outside of the State, although local manufacture of this product has intermittently assumed some importance.

The most of the extensive deposits are of a nature to be most valuable as land fertilizer. It has also been found by Professor Hilgard 

that gypsum has great value in neutralizing the alkalies present in 

large quantities in some of the valley lands of the State. In many 

cases the deposits are so situated as to be within easy reach of the 

lands which need them most. It is but natural that under such conditions the mining of gypsum as land plaster should become an 

important industry.

DESCRIPTIONS OF LOCALITIES.

Alamo Creek. On Alamo Creek, 16 miles from Santa Maria, in San 

Luis Obispo County, there are a number of bunchy veins scattered 

over an area of 40 acres. Part of the material is white, and part grayish. The veins occur in a clay formation similar to that at Point Sal. 

Little work has been done there.

Amboy beds. Extensive beds of gypsum occur in the Amboy sink, 

near the Santa Fe Railroad, in the eastern part of Mohave Desert. 

They are associated with beds of salt and were discovered while prospecting holes were being sunk in search, of salt. Holes 10 feet deep 

encountered nothing but gypsum, which occurs in nodular or concretionary granules. The quality is apparently very good, although no 

analysis has been made. The deposit is overlain by a thin stratum of 

clay.

Antelope Valley. A deposit lies on the borders of Antelope Valley 

in northern Los Angeles County, a little more than half a mile from 

Palmdale Station on the Southern Pacific Railroad.

The gypsum occurs as a stratum near the surface of a low hill and 

has a thickness of 25 feet. The area covered is about 25 acres. It is 

mined by surface workings. The quality is good, being about 95 per 

cent pure, and the deposit is thought to be almost inexhaustible. The 

g3rpsum is taken to Los Angeles and prepared for use as a fertilizer, 

wall plaster, and .plaster of Paris.

Banking. A deposit of gypsum has been opened at Banning, near 

the Southern Pacific, in Riverside County. The material is shipped 

to CM ton, near San Bernardino, and is used in the manufacture of 

plaster of Paris.

JBitterwater deposit. This deposit is situated on the southwest side 

of Bitterwater Valley, in San Benito County, 10 miles east of Kings
U. S. GEOLOGICAL SURVEY BULLETIN NO. 223 PL. XXI

MAP OF SOUTHERN CALIFORNIA SHOWING GYPSUM, LOCALITIES.
FAIRBANKS.] - CALIFOENIA. 121

City, at an elevation of 1,900 feet. It outcrops along the top of a 

series of ridges, dipping gently westward. It is overlain by clayey 

soils and covers an area of several hundred acres. The upper portion 

of the deposit is composed of massive gray gypsum, and, according to 

analysis, is 90 per cent pure. The thickness of the deposit is from 3 

to 7 feet. This stratum is underlain by another, less pure, containing 

only 40 to 60 per cent, the impurities being lime, clay, and sand. 

The gypsum is soft and marly, and can be advantageously used for 

fertilizing purposes.

Coalinga mine. This mine is situated 9 miles north of Coalinga, 

on the foothills of the Coast Ranges, in Fresno County. The workings consist of open cuts. At one the gypsum was found in a stratum 

10 feet in thickness. The hillside has been penetrated 60 feet. At 

another cut, 100 yards south and a little below, are two beds. They 

are interbedded with clay and sandy calcareous shales. The strata

dip 20° to the southeast. The gypsurn is hauled from the mine to 

Coalinga, and there ground in a mill erected for the purpose. The 

material is used as a fertilizer in Tulare and Kings counties.

Oottonwood Greek. Gypsum deposits of varying quality occur for 

many miles along the lower foothills of the Sierra Nevada, reaching 

from Caliente on the south nearly to Porterville on the north.

In the valley of Cottonwood Creek, 5 miles north of Pampa station, 

on the Southern Pacific Railroad, the beds are rather extensive, and a 

number of mines have been opened. The gypsum here seems to occur 

both as a crust upon the surface and as interstratified beds. The latter vary in thickness from 20 inches to 5 feet, and lie upon a bed of 

marl. This gypsum is not so pure as that upon the surface. The 

surface deposit conforms to the slope of the ground, and seems to have 

been formed through concentration as erosion removed the soft clayey 

and marly strata. The material is sacked and hauled 8 miles to Wade 

station, and is used for fertilizing purposes.

Gypsum Canyon. A deposit lies in a small canyon, known as Gypsum Canyon, on the western slope of the Santa Ana Range, in Orange 

County. It is in the form of a bunchy vein in rocks of probable Upper 

Cretaceous age. The strata are chiefly sandstone. The deposit has a 

thickness of 8 to 10 feet. The gypsum is white and crystalline and 

almost as clear as alabaster. At one spot a mass of dolomite was 

found inclosed in it.

Kettleman Valley. This is situated in southwestern Kings County, 

at an elevation of 425 feet. The deposit has been worked intermittently and the material obtained used as a fertilizer. Some selected 

samples showed 94 per cent gypsum, but the rock mined is generally 

poorer. It has been developed by open cuts.

Paoli mine.- This mine is situated on the eastern edge of the coast 

ranges 5 miles south of Big Panoche and 18 miles southwest of Men-
122 GYPSUM DEPOSITS IN THE UNITED STATES. [BULL. 223.

dota station, in Fresno County. The main ridge on which the deposit 

occurs extends for 300 feet along the north side of Tome Creek. 

From this ridge four spur ridges extend down in a northerly direction. 

The deposits occur on all of these ridges, dipping slightly toward the 

valley on the east. The deposit on the main ridge, where most of the 

work has been done, shows a thickness of 30 feet, but the bottom has 

not been exposed. At the foot of the east slope of the third spur 

there is exposed in a canyon a bed 18 feet thick. Everything indicates that these deposits are very large.

Analyses made in the laboratory of the Agricultural Department at 

Berkeley gave the following results:

Analysis of gypsum from Paoli mine, California.

No. 1. Summit of main ridge. ...... ................

No. 1. Second spur ................................

No. 3. Third spur. ................................

No. 4. Fourth spur. ...............................

Gypsum.

95.24

94.74

92.90

82.20

Clay.

1.98

1.52

2.60

8.21

Moisture 

and lime.

2.78

3.74

4.50

9.59

The average of the whole deposit is probably about 90 per cent. 

This excels in purity most of the gypsum found in California, and portions may be good .enough for plaster of Paris.

Point Sal. The deposits at Point Sal have been considered among 

the most important, both as to quality of gypsum and as to extent of 

the deposits. Although they are among the earliest worked in the 

State, they have been tying idle for some years. The}7 have the form 

of bunchy veins in soft Tertiary clays, and have been worked by means

of tunnels. The gypsum is conveniently situated for shipment, as it 

is only necessary to haul it 2 miles to a chute erected upon the cliffs. 

From this it is lowered by cable to ships moored just outside the rocks. 

The material is white and very pure, approaching alabaster in appearance. The veins are not well exposed. They are said to be two in 

number and to dip at varying angles. The gypsum can be mined and 

placed on shipboard for about $2 a ton.

Ojai Valley. There is an undeveloped bed of gypsum on the hill 

below the grade that leads to the upper Ojai Valley in Ventura County. 

It is exposed for a width of 15 to 20 feet in a canyon on the south side 

of the road and dips slightly to the east. Another outcrop, perhaps 

the same bed, appears a mile distant, on the opposite side of the hill. 

The locality is so situated that it can be reached by the construction of 

a short road.

SanJoaquin Valley mine. This mine is situated 4 miles northwest of 

Coalinga, in Fresno County, and at an elevation of 1,000 feet. The
FAIRBANKS.] CALIFOKNIA. 123

gypsum occurs in bunclty deposits in a recent formation and varies 

much in character. It has been mined for use as a fertilizer.

Santa Barbara Canyon. The gypsum veins are on the east side of 

Santa Barbara Canyon, in Santa Barbara County. The material is of 

good qualit}r, some of it being as clear as alabaster and capable of taking a good polish. The outcrop is much broken and the development 

does not show whether gypsum is present in sufficient quantity to pay 

for working. The veins are inclosed in Tertiary clays, which are 

extensively developed in this region and everywhere carry more or 

less gypsum.

Sunset district. This district is situated on the eastern slope of the 

coast ranges southwest of Bakersfield. The region is particularly 

noted for its oil wells. The gypsum occurs as a soft, chalk-like rock 

interstratified with other beds. It sometimes reaches a thickness of 

several feet. The formation is similar to that on Cottonwood Creek.

Analyses of specimens in the laboratory of the State mining bureau 

gave 86.07 gypsum for one and 60 to TO per cent for others.

GEOLOGIC RELATIONS.

The gypsum deposits of California appear generally to be confined 

to formations of Neocene age. There are some exceptions to this 

rule, notably in the case of the Gypsum Canyon deposit, in rocks of 

Cretaceous age, and those in the Amboy sink, probably of Pleistocene 

origin.

The Neocene in California is characterized in many localities by 

extensive beds of clay and clay shales which are gypsum bearing. 

The clays of the Monterey formation, which belong to the Lower Neocene, are particularly prominent through the central portion of the 

coast ranges. Another horizon of later Neocene age is particularly 

extensive about the borders of the southern portion of the Great Valley. This formation contains the interstratified gypsum beds, which 

are generally of poorer quality than the veins and are more particularly adapted -to use as a fertilizer. The argillaceous beds in the 

recent geological formations are generally impregnated with gypsum 

and alkalies, a fact leading to the supposition that they may have 

been formed in basins more or less separated from the open ocean.

INDEX.

Page.

Absaroka Mountains, Wyo., gypsum beds in. 84 

Acme, Tex., gypsum deposits at............ 69

Adams, G. I., introduction by.............. 11

paper by, on geology, technology, and

statistics of gypsum ............ 12-32

Age, geologic. See Geologic age.

Alabaster, character of............ 13,20 (PI. IV)

Alabaster, Midi., gypsum deposits near.. 45,46,47

Alamo Creek, Cal., gypsum beds on........ 120

Alien, E. T., analyses of gypsum by........ 106

Amboy sink, California, gypsum beds In.. 120,123 

Ancho, tf. Mex., gypsum deposits at....... 90

Anhydrite, origin and properties of........ 14

Antelope Valley, California, gypsum beds

in............................... 120

Arietina clay, gypsum beds in.............. 72

Armington, Mont., gypsum deposits near.. 75 

Arizona, gypsum deposits in ............. 100-101

gypsum product of, with prices and

value........................... 30,31

Banning, Cal., gypsum deposits at......... 120

Bear Island, Florida, gypsum deposits at.. 48 

Belen, N. Mex., section near................ 97

Bighorn Mountains, Wyoming, gypsum deposits in and near.............. 83

Bitterwater Valley, California, gypsum

beds in ....................... 120-121-

Black Hills, gypsum-bearing formations in,

map showing................... 77

gypsum deposits in.................. 76-78,85

Blake, W. P., paper by, on Arizona gypsum

beds.......................... 100-101

Blue Rapids, Kans., gypsum deposits at. 53,54-56 

section at............................... 65

Boutwell, J. M., paper by, on Utah gypsum

deposits ...................... 102-105

BrazosRiver,Texas,SaltForkof,section on. 71 

Bridger, Mont., gypsum deposits near...... 75

Buffalo, Wyo., gypsum beds near .......... 83

Burns, Kans., gypsum deposits near ....... 53,57

California, gypsum deposits in........... 119-123

gypsum deposits in, map showing...... 120

view showing.......... 102 (PI. XIX)

gypsum product of, with prices and

values................. 27,28,29,30,31

Cambria, Wyo., gypsum deposits near...... 78

Canada, gypsum imported from............ 32

Cangilon River, New Mexico, gypsum beds

on .............................. 94

Canyon, Colo., gypsum deposits at......... 86,87

Carboniferous rocks, gypsum deposits in... 17,

' 37,47,51-52,74,75,88,100,112

Carter, Okla., section near ................. 64

Paga 

Cascade Springs.S.Dak.,gypsum deposits at. 77-78

section at............................... 78

Casper, Wyo., gypsum deposits near ....... 81

Castilia, Ohio, gypsum deposits near....... 40

sections at.............................. 40

Cedartop gypsum bed, Oklahoma, location

Of............................... 66

Cement, Okla., gypsum deposits at ...'..... 61

Chama River Valley, New Mexico, gypsum

deposits in...................... 94

Chancy gypsum bed, Oklahoma, location of. 66 

Cloud Chief, Okla., section near ........... 64

Coalinga, Cal., gypsum deposits at......... 121

Cody, Wyo., gypsum beds near............. 84

Cold Brook, S. Dak., sections on ........... 76,78

Collingsworth gypsum bed,Oklahoma, loca-

 tion of.......................... 66

Colorado, gypsum deposits in .............. 86-88

gypsum product of, with prices and

value .................. 27,28,29,30,31

Connant Creek, Wyoming, gypsum beds

near............................ 83

Cope, E. D., cited on gypsum deposits in

New Mexico.................... 94

Cottonwood Creek, Colorado, gypsum deposits on........................ 121

Coyote Creek, New Mexico, gypsum depos-.

its on ............................ 92-93

Cretaceous rocks, gypsum deposits in ... 74,75,90 

Cummins, A. F., cited on Texas gypsum deposits ..................... 69,70-71,73

sections cited from report of............ 70-71

Customs districts, imports of gypsum by,

table showing ................... 32

Darton, N. H., cited on age of gypsumbearing portions of Red Beds... 85 

paper by, on gypsum deposits in South

Dakota ......................... 70-78

Day, D. T., paper by, on Florida gypsum

deposits......................... 48

Dayton, Wyo., gypsum deposits at ......... 80

Deer Creek, Colorado, section on........... 87

Delaware Creek, Texas, gypsum deposits

on .............................. 71

Del Rio clay, gypsum beds in .............. 72

Des Moines River, Iowa, section on........ 52

Dillon, Kans., gypsum deposi ts near....... 67

Durango, Colo., gypsum deposits near ..... 88

Eckel, E. C., paper by, on New York gypsum deposits.................... 33-35

paper by, on Virginia gypsum deposits. 36-37 

Elreno, Okla., gypsum deposits near....... 62-63

El Rito, N. Mex., sections at and near ..... 96,97

125
126 INDEX.

Page. 

England, gypsum imported from........... 32

Fairbanks, H. W., paper by, on California

gypsum deposits.............. 119-123

Ferguson, Okla., gypsum beds at........... 63

section at............................... 62

Ferris Mountains, Wyoming, gypsum beds

in................................ 82-83

Fillmore, Utah, gypsum beds near ......... 107

Fletcherville, Ohio, gypsum deposits at.... 39,41

gypsum deposits at, views of.......40 (PI. X)

Florida, gypsum deposit in................. 48

Fort Apache Reservation, Ariz., gypsum

beds on....................... 100,101

Fort Dodge, Iowa, gypsum deposits at, map

showing........................ 50

section at............................... 51

France, gypsum imported from ............ 32

FreezeoutHills, Wyoming, gypsum beds in. 82 

Gallup, N. Hex., gypsum beds near........ 99

Garden of the Gods, Colorado, gypsum deposits in........................ 86-87

Geologic age of gypsum deposits, by periods,

Carboniferous ..... 17,37,51-52,85,100

Carboniferous, Mississippian.. 17,47,75,88,112 

Permian....... 17,52,59,66-67; 73,76,85,91

Cretaceous........:............. 90-91,110,123

Jurassic ............ 17,88,109,110,112,117,118

Pleistocene............................. 123

Silurian ....................... 17,34-35,44,72

Tertiary ................ 17,72,100,109,113,123

Triassic............ 88,100,101,110.112,117,118

Geologic age of gypsum deposits, by States,

Arizona....................... 100-101

California ............................. 17,123

Colorado ............................... 88

Iowa................................. 17,51-52

Kansas ................................. 17,59

Michigan............................... 17,47

Montana ............................... 17,75

Nevada....................... 112-113,116-118

New Mexico......................... 17,90-91

New York...........................' 17,34-35

Ohio.................................... 17,44

Oklahoma........................... 17,66-07

Oregon................................. Ill

South Dakota........................... 17,76

Texas.................................... 17,73

Utah.................................. 108-110

Virginia.................................17,37

W yoming............................... 85

Geology, technology, and statistics of gypsum, paper by G. I. Adams on.. 12-32 

Gilbert, G. K., cited on Utah gypsum beds. 17, 

103,104,109,110 

Glade Spring, Va., gypsum industry at .... 37

Glass Mountain, Oklahoma, gypsum deposits at ........................ 63

gypsum deposits at, view showing ..... 64

(PL XV)

Gould, C. N., paper by, on Oklahoma gypsum deposits.................... 60-67

Grandville, Mich., gypsum deposits near.. 45,

46,47 

Great Britain, gypsum imported from...... 32

Grey Bull River, Wyoming, gypsum beds

on.............................. 84

Page.

Grimsley, G. P., paper by, on Kansas gypsum deposits.................... 53-59

paper by, on Michigan gypsum deposits 45-47

Gros Ventre Mountains, Wyoming, gypsum

beds in ......................... 84

Guadaloupe Mountains, Texas, gypsum deposits near...................... 71

Gyp Hills, Oklahoma, gypsum deposits in.. 63

Gypsite, character of....................... 13

origin of................................ 16

Gypsum, analysis of................... 78, ICa, 122

chemical composition of............... 12,18

cleavage of .................... 13,16 (PI. II)

colors of................................ 12

crystalline forms of, figures showing .. 13 

formation of, in laboratory............. 15

hardening of, methods for.............. 20

hardness of.............................. 12

imports of .............................. 31-32

manufacture of......................... 18-25

mining of............................... 21

origin of................................ 15-17

production, value; and prices of, tables

showing......................... 26-32

solubility of............... 12,13-14,22 (PI. V)

specific gravity of...................... 12

.technology of........................... 18-25

uses of.................................. 24-25

Gypsum, Colo., gypsum deposits near...... 87

Gypsum Canyon, California, gypsum deposits'in........................ 121

Gypsum City, Kans., gypsum deposits at

and near..................... 53,56-57

Gypsum deposits, geologic ages of.......... 17-18

See also Geologic ages, 

origin of................................ 15-17

Gypsum industry, historical sketch of...... 24

producing localities of, map showing .. 24 

statistics of............................. 25-32

Gypsum rock, character of.........13,20 (PL IV)

Gypsum sands, deposits of.................. 13,17

Gypsum station, Ohio, deposits near ....... 39

sectionnear............................ 43

Hayes, C. W., letter of transrnittal by ...... 9

Haystack gypsum bed, Oklahoma, location

Of..................'............. 66

Herrick, C. L., cited on white sands of New

Mexico......................... 17

Herrick, H. N., paper by, on gypsum deposits in New Mexico .......... 89

Hill, B. F., paper by, on Texas gypsum deposits. .......................... 68-73

Historical sketch of gypsum industry ...... 24

'Holston River, Virginia, North Fork of, gypsum deposits on ................ 36-37

section across........................... 37

Hope, Kans., gypsum deposits at........... 56

Hot Springs, S. Dak., gypsum deposits at

and near ....................... 76

gypsum deposits near, view of-.78 (PL XVI)

Howell, E. E., cited on Utah gypsum bed .. 109

Humboldt Mountains, Nevada, gypsum deposits near ................... 113,114

Hunters Hot Springs, Mont., gypsum deposits at......................... 74-75

Hurd mine, Linden, N. Y., section at...... 34
INDEX. 127

Page. 

Hyde, F. A., acknowledgment to .......... 102

Imports of gypsum, table showing.......... 32

Indian Territory, gypsum product of, with

prices and value............ 29, 30, 31

Iowa, gypsum deposits in .................. 49-52

gypsum-bearing area in, map showing . 50 

gypsum product of, with prices and

value..................27, 28, 29, 30, 31

Jackson, James, acknowledgment to....... 102

Jcmez Peak, New Mexico, gypsum beds

near ............................ 95

Jemez River, New Mexico, gypsum beds

near............................ 94-95

Johnson, P. W., cited on gypsum deposits

in New Mexico................. 92, 93

Jurassic rocks, gypsum deposits in.......... 17

88, 91, 94, 109, 112, 118 

Kansas, gypsum deposits in................. 53-59

gypsum deposits in, map showing ..... ' 54

gypsum product of, with prices and

value.................. 27,28,29,30,31

Keechi Hills, Oklahoma, gypsum deposits in 64 

Kennedy, William, cited on Texas gypsum

deposits ........................ 72

Kettleman Valley, California, gypsum beds

in ........................'...... 121

Kibbey, Mont., gypsum deposits near...... 75

Kings City, Gal., gypsum deposit near, view

of...................... 102 (PI. XIX)

Kiowa Peak, Texas; section at............. 70

Kiser gypsum bed, Oklahoma, location of.. GO 

Knight, W. C., paper by, on gypsum deposits in Wyoming................. 79-85

Laguna, N. Mex., sections near ............ 96,97

Lakes, Arthur, paper by, on Colorado gypsum deposits ................... 86-88

Laramie, Wyo., gypsum deposits near...... 79,80

section near............................ 81

Laramie Mountains, Wyoming, gypsum

beds in......................... 80-82

Las Vegas, N. Mex., gypsum deposits near. 93 

Linden, N. Y., section at................... 34

Lindgren, Waldemar, paper by, on Oregon

gypsum deposits................ Ill

Longford, Kans., gypsum deposits at....... 53,57

Louderback, G. D., paper by, on Nevada

gypsum deposits.............. 112-118

Loveland, Colo., gypsum deposits near .... 86,87

Lovelocks, Nev., gypsum beds near........ 112,

113-115,117,118 

gypsum deposits at, view showing..... 116

(PI. XX) 

Lucero, N. Mex., section near.............. 93

Malone Mountains, Texas, gypsum deposits

in............................... 71-72

Mangum, Okla., section near .............. 65

Manzana Mountains, New Mexico, gypsum

beds in......................... 95-96

Marcy, Capt. R. B., cited on gypsum deposits of Texas............'......... 68-69

Marcy Range, Oklahoma, gypsum deposits

in............................... 63

Marsh and Company, gypsum quarry of, 

near Port Clinton, Ohio, views 

at............................... 42

Medicine Bow Mountains, Wyoming, gypsum beds in..................... 82

Page. 

Medicine Lodge, Kansas, gypsum deposits 

near....................... 53,57-58,63

section near............................. 58

Mesa Gigante, New Mexico, gypsum deposits near......."............... 91,96-97

section at............................... 96,97

Michigan, gypsum deposits in.............. 45-47

gypsum product of, with prices and

value...!.............. 27,28,29,30,31

Mississippian rocks, gypsum deposits in.... 17,47

Molmve Desert, California, gypsum beds in. , 120 

Montana, gypsum deposits in .............. 74-75

gypsum product of, with prices and

values ....................... 29,30,31

Morrison, Colorado, gypsum deposits near. 86,81 

Moses, A. J., cited on gypsum crystals from

Utah............................ 108

Moundhouse, Nevada, gypsum beds at..... 112,

115-116,117,118

Mulvane, Kansas, gypsum deposits near... 67 

Nacimiento Mountains, New Mexico, gypsum beds near.................. 94

section near............................ 94

Neocene rocks, gypsum beds in ............ 123

Nephi, Utah, gypsum beds near............ 102-

103,104-107,108-109

gypsum deposit near, view of.. 102 (PI. XIX) 

section at............................... 105

Nevada, gypsum deposits in.............. 112-118

gypsum deposit iu, view showing...... 116

(PI. XX)

map of part of, showing developed gypsum deposits..................... 114

New Brunswick, gypsum imported from... 32 

Newman Hill, Colorado, gypsum deposits

at............................... 88

New Mexico, gypsum deposits in........... 89-99

gypsum deposits in, map showing ..... 89

view showing............. 98 (PI. XVIII)

white sands of, reference to............ 17

New York, gypsum deposits in............. 33-35

gypsum deposits in, map showing...... 34

gypsum product of, with prices and

value.................. 27,28,29,30,31

Salina group in, map showing area of.. 34 

sections in, showing location of gypsum

deposits ........................ 34,35

Novia Scotia, gypsum imported from ...... 32

Ohio, gypsum deposits and industry in,

paper on........................ 38-44

gypsum deposits in, map showing...... 38

views of........... 40 (PI. X),42 (PI. XI)

gypsum product of, with prices and

value..................... 28,29,30,31

Ojai Valley, California, gypsum deposits at. 122 

Okarche, Oklahoma, gypsum deposits at... 61 

Oklahoma, geologic formations in, section

showing........................ 66

gypsum deposits in..................... 60-67

map showing....................... 60

viewsof ..................... 64 (PI. XV)

gypsum products of, with prices and

value.................. 27,28,29,30,31

Oregon, gypsum deposits in................ Ill

gypsum products of, with prices and

value........................... 30,31

Orton, Edward, cited on Ohio gypsum beds. 38,44
128 INDEX.

Page. 

Oscuro Mountains, New Mexico, gypsum

beds in .......................... 98

Owl Creek 'Mountains, Wyoming, gypsum

beds in ......................... 84

Panasoffkee, Florida, gypsum deposits near. 48 

Paoligypsuinmine, California, depositsat. 121-122 

Peckham,Oklahoma, gypsum deposits near. 61,62 

Pecos River Valley, New Mexico, gypsum

deposits in...................... 92

Penrose, R. A: F.,' cited on Texas gypsum

deposits ........................ 72

Peppel, S. V., paper by, on Ohio gypsum

deposits ........................ 38-44

Permian rocks, gypsum beds in. 17,52,59,66,91,95 

of Kansas, limits of, map showing...... 54

Perry Park, Colorado, gypsum deposits in.. 86,87

Plasterco,Virginia, gypsum deposits near.. 36-37

Plaster of Paris, "accelerators" used with. 20

hardening of, methods for.............. 20

"retarders" used with.............. 19,22-23

set of, theory concerning............... 18-19

uses of.................................. 24-25

Platte River, Wyoming, gypsum beds near. 83 

Pleistocene rocks, gypsum beds in.......... 123

Point Sal, California, gypsum deposits at... 122 

Port Clinton, Ohio, gypsum deposits near,

map showing................... 38

sections near........................... 40-43

Prior Mountains, Wyoming, gypsum beds

Puerco River, New Mexico, gypsum beds

near............................ 94-95

Pyramid Mountain, New Mexico, gypsum

beds at ......................... 96

sections near ........................... 95,96

Quanah, Texas, gypsum deposits near ..... 69

Ransome, F. L., cited on Colorado gypsum

deposits ........................ 88

Rattlesnake Mountains, Wyoming, gypsum

beds in ......................... 83

Rawlins, Wyoming, gypsum beds near..... 82

Red Beds, character, thickness, and age of. 85 

gypsum deposits in, New Mexico....... 89-99

. South Dakota....................... 76-78

Texas............................... 73

Wyoming........................... 79-85

map showing exposures of, in New

Mexico......................... 89

in Wyoming........................ 80

section of............................... 81

view showing butte composed of....... 78

(PI. XVI)

Red Butte, South Dakota, gypsum bed at.. 78 

view of ......................... 78 (PI. XVI)

Red Butte station, Wyoming, gypsum deposits at ........................ 79-80

Red River Valley, Oklahoma, gypsum deposit at, view showing.......... 64

Rico, Colorado, gypsum deposits near...... ,88

section at............................... 88

Rio Grande Valley, New Mexico, gypsum

beds in......................... 94-99

Rio Jemez, New Mexico, gypsum beds near. 94-95 

Rio Puerco, New Mexico, gypsum beds

near ..........:................. 94-95

Rio Salado, N. Mex., gypsum beds near.... .94

section at............................... 97

Rio San Jose, New Mexico, gypsum beds

near............................ 96-97

section near............................ 96

Hi to Quemado, N. Mex., gypsum beds near 99 

Rock gypsum, character of.... ....13, 20 (PI. IV.)

Rondout formation, gypsum deposits in.... 44

Rosemont, Ariz., gypsum beds near........ 100

Russell, I. C., cited on Utah gypsum deposits ........................... 105

Salado River, New Mexico, gypsum beds

near............................ 94, 97

Salina, Utah, gypsum beds near. 102,103,107,109 

Salina group, New York, distribution and

relations of..................... 35

gypsum deposits in .................... 35, 47

map showing area of ................... 34

Salt, association of, with gypsum.......... 14,16

Salt Creek Range, Wyoming, gypsum deposits in........................ 84-85

Salt Creek Valley, Utah, gypsum deposits

in and near.......... 102, 103,107,108

Salt Flat, Texas, section at................. 70

Salt Forkof Brazos River, Texas, section on. 71 

Saltville, Va., gypsum deposits near....... 36-37

gypsum deposits near, map showing... 38 

section near............................ 37

San Andreas Mountains, New Mexico, gypsum beds in .................... 98

Sandea Mountains, New Mexico, gypsum

beds near.....'.................. 95

Sandusky, Ohio, gypsum deposits near, map

showing........................ 38

Sandusky Bay, Ohio, section at............ 40

San Joaquin Valley, California, gypsum deposits in ...................... 122-123

San Jose River, New Mexico. See Rio San

Jose. 

San Juan mining region, Colorado, gypsum

deposits in...................... 88

San Pedro River, Arizona, gypsum beds

.along......................... 100-101

Santa Barbara Canyon, California, gypsum

beds in.......................... 123

Santa Catalina Mountains, Arizona, gypsum

beds in ....................... 100,101

Santa Rita Mountains, Arizona, gypsum

bedsin ......................... 100

Satin spar, appearance of.......... 13,16 (PI. II)

Selenite, character and crystalline forms of. 13,

14 (PI. I) 

deposits of....:......................... ' 72

plates showing .......... 14 (PI.I), 16 (PI.II)

Seminole Mountains, Wyoming, gypsum

bedsin.......................... 82

Shimergypsum bed, Oklahoma, location of. 63 ' 

Shirley Mountains, Wyoming, gypsum beds

in............................... 82

Shumard, G. H., cited on Texas gypsum

deposits.. r...................... 69

Sierrita Mountains, Arizona, gypsum deposits in.......................... 100,101

Silurian rocks, gypsumdeposits in. 17,34-35,44,47 

Socorro, N. Mex., gypsum deposits near.... 95-96
INDEX. 129

Page 

Soldier Creek, Iowa, sections on............ 50,51

Solomon, Kans., gypsum deposits at ....... 5C

section at........:...................... 56

South Dakota, gypsum beds in.............. 7G-78

gypsum deposits in, view showing..... 78

gypsuni product of, with prices and

value.............; .......... 29,30,31

South Wash, Utah, gypsum beds in......... 102,

104,107-108,110, 

Spearfish formation, South Dakota, gypsum

beds in .......................... 70-78

Spencer, A. C., cited on Colorado gypsum

beds............................ 88

Spring Mountain Range, Nevada, gypsum

beds in.......................... 112

section in............................... 112

Staked Plains, Texas, gypsum deposits ia

and near .................... 70,91-92

Stanton, T. W., cited on age of gypsumbearing rocks of Texas ......... -73

Statistics of gypsum industry, tables giving 25-32

Steiger, George, analysis of gypsum by..... 78

Stevenson, .T. J., acknowledgments to...... 37

Sulphur, association of, with gypsum...... 14-15

Sylvania, Ohio, gypsum deposits near...... 38

Tafl, J. A., cited on gypsum deposits of

Malone Mountains, Texas...... 72

Talmage, J. E., cited on Utah gypsum beds. 107-

108,110 

Tertiary rocks, gypsum deposits in......... 17,

88,113, 119,123 

Texas, gypsum deposits in.................. 68-73

gypsum deposits in, map showing location of.......................... 68

gypsum product of, with prices and

value................. 27, 28, 29, 30, 31

Thermopolis, Wyo., gypsum beds near..... 83

Thorpe, T. E., cited on properties of gypsum ............................ 106

Page. 

Triassic rocks, gypsum beds in............. 76,

88, 91, 100, 112, 117, 118 

Tucson, Ariz., gypsum beds near ........ 100,101

Tularosa, N. Mex., gypsum beds near ...... 98

Twomile Creek, Iowa, section on........... 52

United Kingdom, gypsum imported from.. 32 

Utah, gypsum deposits in................. .102-105

gypsum deposits in, view of............ 102

gypsum product of, with prices and

value........................ 29,30,31

gypsum sands in........................ 17

Virginia, gypsum deposits in............... 36-37

gypsum deposits in, map showing area of 36 

gypsum, product of, with prices and

value.................. 27,28,29,30,31

Virginia Mountains, Nevada, gypsum beds

in..................... 114,115-116,117

Watonga, Okla., gypsum deposit at........ 61

Weed, W. H., paper by, on Montana' gypsum deposits.................... 74-75

White Mountain, Utah, gypsum beds near. 102,

103-104,107,109-110

White Mountains, New Mexico, gypsum deposits in ........................ po

White sands of New Mexico, location and

features of...................... 98-99

Wilder, F. A., cited on properties of gypsum. 100 

paper by, on Iowa gypsum deposits.... 49^52

Wills Point gypsum bed, selenitc crystals

found in........................ 72

Wind River Mountains, Wyoming, gypsum

deposits in...................... 84

Wyoming, gypsum deposits in ............. 79-85

gypsum deposits in, map showing...... 80

view showing ............... .78 (PI. XVI)

gypsum product of, with prices and

value .................. 27,28,29,30,31

Red Beds in, map showing............. .80

Zuni region of New Mexico, gypsum beds in 99

PUBLICATIONS OF UNITED STATES GEOLOGICAL SURVEY.

[Bulletin No. 223.]

The serial publications of the United States Geological Survey consist of (1) Annual 

Reports, (2) Monographs, (3) Professional Papers, (4) Bulletins, (5) Mineral 

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SERIES A, ECONOMIC GEOLOGY.

B 21. Lignites of Great Sioux Reservation: Report on region between Grand and Morean rivers,'

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B M. Nature and origin of deposits of phosphate of lime, by R. A. F. Penrose, jr., with introduction

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B 111. Geology of Big Stone Gap coal field of Virginia and Kentucky, by M. R. Campbell. 1893. 106

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B 132. The disseminated lead ores of southeastern Missouri, by Arthur Winslow. 1890. 31 pp. 

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B 139. Geology of Castle Mountain mining district, Montana, by W. H. Weed and L. V. Pirsson. 1896.

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B 178. El Paso tin deposits, by W. H. Weed. 1901. 15 pp., 1 pi. 

B180. Occurrence and distribution of corundum in the United States, by J. H. Pratt. 1901. 98 pp.,

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B 182. A report on the economic geology of the Silverton quadrangle, Colorado, by F. L. Ransome.

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B 184. Oil and gas fields of the western interior and northern Texas Coal Measures and of the Upper

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(Out of stock.) . B 193. The geological relations and distribution of platinum and associated metals, by J. F. Kemp.

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B 198. The Berea grit oil sand in the Cadiz quadrangle, Ohio, by W. T. Griswold. 1902. 43 pp., 1 pi. 

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B 200. Reconnaissance of the borax deposits of Death Valley and Mohave Desert, by M. R. Campbell.

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II ADVEETISEMENT.

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PP 11. Clays of the United States east of the Mississippi River, by Heinrich Ries. 1903. 298 pp., 9 pis. 

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B213. Contributions to economic geology, 1902; S. F. Emmons,. C. W. Hayes, geologists in charge.

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B 218. Coal resources of the Yukon, Alaska, by A. J. Collier. 1903. 71 pp., 6 pis. 

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PP 20. A reconnaissance in northern Alaska, in 1901, by F. C. Schrader. 1904. 139 pp., 16 pis. 

PP 21. Geology and ore deposits of the Bisbee quadrangle, Arizona, by F. L. Ransome. 1904. pp.,

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B 223. Gypsum deposits of the United States, by G. I. Adams and others. 1904. 129 pp., 21 pis.

Correspondence should be addressed to

THE DIRECTOR,

UNITED STATES GEOLOGICAL SURVEY,

WASHINGTON, D. C. 

APRIL, 1904.
LIBRAEY CATALOGUE SLIPS.

[Mount each slip upon a separate card, placing the subject at the top of the. 

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Adams, George I[rving]

. . . Gypsum deposits in the United States, by 

George I. Adams and others. Washington, Gov't 

print, off., 1904.

129, lil p. illus., 21 pi. (incl. maps). 23£om. (U. S. Geological survey. 

Bulletin no. 223.)

Subject series A, Economic geology, 30. -

Contains contributions by various members of the U. S. Geological survey 

and others.

Adams, George I[rving]

^ ... Gypsum deposits in the United States, by 

f George I. Adams .and others. Washington, Gov't 

print, off., 1904.

129, III p.. illus., 21 pi. (incl. maps)'. 23£om. (U. S. Geological survey. 

Bulletin no. 223.)

Subject series A, Economic geology, 30.

Contains contributions by various members of the U. S. Geological survey 

and others.

U. S. Geological survey.

Bulletins.

no. 223. Adams, G. I. Gypsum deposits in the United 

States, by G. I. Adams and others.

U. S. Dept. of the Interior.

tu

I '- see also i*

| U. S. Geological survey.

in