UNITED STATES DEPARTMENT OF THE INTERIOR 

Ray Lyman Wilbur, Secretary

GEOLOGICAL SURVEY 

George Otla Smith, Director

Bulletin 820

NITRATE DEPOSITS 

IN SOUTHEASTERN CALIFORNIA

WITH NOTES ON DEPOSITS IN SOUTHEASTERN ARIZONA 

AND SOUTHWESTERN NEW MEXICO

BY

L. F. NOBLE

9A

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UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON: 1931

. ». Forsaleby the Superintendent of Documents, Washington. D. C. - - Price 45 cents 

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CONTENTS

Page

Introduction____ . .___ ___________ 1

 , Explorations_____________________________________ 1

General character of the deposits________ _ __________ 2

General conclusions as to value________.________________________ 2

Present investigation._____________________________________________ 3

* Middle and northern Mohave Desert_-___.__________________ 5

Barstow syncline_.._________________________________ 5

^ Coolgardie Lakes________.____;_-_._-______________ 8

^ Leach Point Valley________________________________ 9

Pilot nitrate field_________________________________ 10

4- Leach Lake.......____________.__.._._______. _._ 13

Owl Spring nitrate field...___________________________ 16

*> Nitrate near Twenty-nine Palms Springs.___________________ 25

Reason for investigation....______________________ 25

* Location and general topographic features_______ _ _ 25

General geology. 27

* Exploration.___________ _____________ 29

^ Conclusions....-________________________ ... 32

Nitrate in the valley of the Colorado River___________________ 32

* Occurrences. ... _ _______ _ 32

Previous exploration____________________________ 33

Reason for investigation______________________.____ ________ 35

Plan and results of investigation.___________________________ 36

** West WeU tract...____________________________ 38

Location and extent_____________________ __ __ 38

General geologic features.__________________ _ _ 38

^ Areas containing nitrate _________________________________ 39

Clay-hill deposits._____..__________ 39

«fr Method of exploration___________________________ 39

The 400-acre area________________________ 40

^ Other areas_______________________________________ 45

Deposits associated with volcanic rocks _______ __ __ _______ 47

^ Vivet Eye tract..________________._-____-_ __ 49

Beal tract_________________._________ _____ ____ 55

K Vidal tract-_-_-_-_-_-_-________--_----_--- -- _- -_- 55

^ Danby Lake...__________________________________________________ 57

Ratliff nitrate claims and other deposits near Shoshone... _ __ 62

Location_____________________________________________________ 62

Reason for investigation.______________________________________ 62

__ General geology _ . 64

Lake beds________________________________________ 65

* Recent alluvium._______________________ __ ____._. 67

General considerations__________..__________-___-_-_ ___- 67

Exploration. ____°_______._______ 68

^ Summary of tests___________________________________________ 70

Conclusions.________________________________________^________ 70

.> Cave deposits_______--__-_____-___________ ____________ 70

Bed of volcanic ash_________________________________________ 71

* in

V HhOO.SJ'Oo;3)
IV CONTENTS

	/" 

	Page

Eberenz-Beach nitrate claims, northeast of San Simon, Ariz ._______ 71

Reason for investigation..-._____________________ 71

Location_____.________________ .____. 71

General geology ______________________ ______ 72

Supposed mode of occurrence of the nitrate_________________ 73 "-

Work done_______________.________ ___ 73

Examination. ___________________________ ___ 73

Thetuff__________._______________________________ 74

Surface deposits of nitrate__________________ 74

On roofs of alcoves.____________________ 74 '*

On back walls of alcoves...,________________ 75

On floors of alcoves_1__________ ___ 75 ^

Analyses_____________________________ 75

Origin______________________________ 76 '*

Nitrate in the tuff.____________ _ 77

Tests in open cuts_______________ ___ 77

Tests and samples in tunnel____ . _______ 77 -<|

Conclusions. ___________________________ ______ 78

Hungerford-Moore nitrate claims in Animas Valley, N. Mex________ 80 ^

Location and access____________________ 80

General geologic features..._____________ 81 I"

Reason for examination.______________________________________ 82

Examination_____________________________________ 82 "*

Conclusions. ________________________________«___ 85

Random tests in areas of Tertiary strata__________________ 85

Valleys of Muddy Creek and Virgin River, Nev______________ 86

Furnace Creek, Calif_____________________________ 86

Fish Lake Valley, Nev___________________________ 88 +

Partial analyses of caliche from the nitrate fields of the Amargosa region. _ 88

Complete analyses of blister caliche from the Confidence nitrate field____ 91 -*

Nitrification tests in clay-hill areas and in Leach Lake____"________ 93

Origin of clay-hill nitrate deposits.... ___ 95 r4r *

Analysis of the problem__________________________ 96 ^

Hypotheses_________________ ;______________ 96

Accumulation of caliche____________ ___ ___ 102 ±

Conclusions regarding origin_______________________ 104 e

Deposits of other minerals in Tertiary clays.___________________ 105 ,*

Final comment.__________________________________ 105

Index..___________________________________________________ 107 *

Page 

PLATE 1. Index map of nitrate fields in southeastern California_ _____ 10

2. A, B, Pilot Knob; C, Coolgardie Lake___ - 10

3. A, West end of Pilot nitrate field; B, Leach Lake;oC, Owl Spring. 10

4. A, View south across Mesquite Trough from Mud Hill; B, 

South slope of Mud Hill; C, Prospecting 20-foot bed in Mud 

Hill.___.._.___._._.----_-__._____---_-------______ 26

5. A, General view of 400-acre area 3 miles west of West Well;

B, Upper beds of buff shale in 400-acre area; C, West Well.. 26
5 CONTENTS V

Page

^ PLATE 6. A, Greenish lake-bed shale in Chemehuevi Wash; B, Prospecting greenish clay shale in Chemehuevi Wash_._______ 42 

$ 7. A, Faulted and eroded strata of lake-bed series overlain by alluvium; B, River-worn cobbles lying upon lake-bed series;

* C, Twenty-nine Palms ________...___.___._-____ 42

8. A, Gypsite deposit on east slope of Riverside Peak; B, View

* northeastward along gypsite belt._________________ 42

9. A, Near view of gypsite deposit; B, Prospect in gypsite; C, Prospect pit in buff shale.___________.---__^_--__---_-______ 42

*- 10. A, Shaft No. 2, Danby Lake, 2 miles southwest of Milligan; B,

Drilling with soil auger______________________ 58

(* 11. A, Ratliff claims southwest of Shoshone; B, Ratliff claims

north of Shoshone; C, White bed tested for nitrate_________ 68

"* 12. A, Prospect pits and trench, Ratliff claims; B, Volcanic ash in

lake beds near Shoshone-_-_--_--------------_------__- 74

* 13. A, Cliffs of rhyolite tuff on Eberenz-Beach claims; B, Alcove in

. rhyolite tuff___----_----__---_-_--_---_----------_-_-- 74

14. A, B, Hungerford-Moore nitrate claims--_--_-_-___________ 74

^ 15. A, B, Tertiary strata south of Furnace Creek; C, Panorama of

area covered by Eberenz-Beach nitrate claims__-___-____- 90

t 16. A, B, Blister caliche on green shale, Confidence field.______--_ 90

17. A, B, Nitrate ground in Amphitheater Canyon, Saratoga field. _ 90

**- 18. A, Salt deposit on floor of Death Valley; B, Recent cinder cone

in North Death Valley near mouth of Ubehebe Wash______ 90

19. A, Strand lines, Panamint Valley; B, Strand lines, south end of

Death Valley.. 1 - 90

FIGURE 1. Sketch showing arrangement of soil, caliche, and bedrock of 

,t the clay hills of the Amargosaregion, California.___________ 2

2. Diagrammatic cross section through Mud .Hill, showing position of upper and lower greenish clay zones and relation of 

nitrate-bearing caliche to their outcrop_____-_-__-__-_-_-_ 28

3. Sketch map of claims of Messrs. Ratliff and others southwest

cf Shoshone, Calif ____________---__--____-------------- 63

4. Sketch map of claims of Messrs. Ratliff and others north of

Shoshone, Calif_____-__-_--_------_--------_---------- 64

5. Map showing location of Eberenz-Beach nitrate claims near

San Simon, Ariz______________-___-_'_-_--_-_--_---_-- 72

6. Map showing approximate location of Hungerford-Moore nitrate claims, Animas Valley, N. Mex_____________________ 80

7. Map of Fish Lake Valley and adjacent regions, Nev_ ___ 89

NITRATE DEPOSITS IN SOUTHEASTERN 

CALIFORNIA

WITH NOTES ON DEPOSITS IN SOUTHEASTERN ARIZONA AND 

SOUTHWESTERN NEW MEXICO

By L. F. NOBLE

INTRODUCTION

EXPLOBATIONS

The occurrence of nitrates in the desert region of southeastern 

California has been known for many years, but reports about the 

character and extent of the deposits have been so conflicting that 

there has been no substantial basis for an opinion as to whether the 

deposits are commercially workable. When the United States entered the World War interest in nitrate became very active, and 

many favorable reports concerning the California deposits were 

received by the Interior and War Departments. Some deposits 

were said to be large enough and rich enough to relieve the United 

States of the necessity of importing from Chile the sodium nitrate 

required for making munitions and fertilizers, and as the need of 

using all available shipping for other war work was urgent, the 

Geological Survey was at once called upon to examine the deposits 

and to make a systematic search for nitrate in the entire region. 

These explorations were begun in December, 1917, and were continued until November, 1918. Since that date occasional additional 

examinations have been made, the latest being early in 1928.

Practically every area in southern California known or reported 

to contain nitrate was examined, and other areas where the ground, 

either from its general resemblance to ground known to be niterbearing or for other reasons, seemed likely to contain nitrate were 

tested or prospected.

The deposits in the Amargosa region were the first to be investigated by the Geological Survey.1 The others in California are described in the present report, together with some deposits in Nevada, 

Arizona, and New Mexico, which were examined at about the same 

time.

* Noble, L. F., Mansfield, G. R.( and others, Nitrate deposits in the Amargosa region, 

southeastern California : U. S. Geol. Survey Bull. 724, 1922.

1
NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

GENERAL CHARACTER OF THE DEPOSITS

The nitrate deposits of southern California are generally associated 

with clay beds of Tertiary age. Most of these were laid down in 

nearly flat layers in lakes, but since deposition they have commonly 

been much deformed by faulting, folding, and igneous intrusion. 

The nitrate deposits under consideration are therefore chiefly of 

the " clay hill " type rather than of the " cave " or " disseminated " 

types found in other parts of the United States. The general character of the clay-hill nitrates and of their associated features is 

fully described in the publication cited.2

A typical section across a clay hill in a nitrate field is shown in 

Figure 1. The caliche layer, which consists largely of common salt 

and the sulphates of sodium, calcium, and magnesium, contains most 

of the nitrate, though some traces of nitrate may be found in other 

layers.

Surface of |rouod

^s<^'\-^.FXflorescentMa^r^-rr^C^>>x. *?& ^ '^Mmr^Tr-^-^^-^M^^

Bedrock, upturned 

beds of clay shale 

and sandstone

FIGURE 1. Sketch showing arrangement of soil, caliche, and bedrock of the clay hills 

of the Amargosa region, California

Some of the areas of Tertiary beds have been reported to contain 

vertebrate fossil remains, but only one area, the Barstow syncline, 

has been searched systematically for them. (See p. 6.)

GENERAL CONCLUSIONS AS TO VALUE

As the findings of the Geological Survey with regard to the commercial possibilities of the nitrates in the Amargosa region 8 are 

applicable with even greater force to the districts herein described, 

they are repeated here:

The ground in all the nitrate fields is rugged and broken, making transportation and mining somewhat difficult. The areas containing the higher-grade 

portions of nitrate-bearing caliche are small, only a few acres each at best, 

and these portions of the deposits are very irregular, pockety, or patchy. The 

caliche layer itself is rarely more than 4 or 5 inches thick, even in the best 

parts of the more favorable areas, and thus a large area would have to be 

worked over to obtain any great quantity of nitrate. The caliche underlies 

soil which would have to be removed in mining, and these two layers are in 

places exceedingly difficult to separate, the one grading almost imperceptibly

a Noble, L. F., and others, op. cit., pp. 6-10.

¥

"4

V 

v

8 Idem, p. 10.
PRESENT INVESTIGATION

f.,

into the other. A similar difficulty is involved in that [much of] the caliche

«> has no distinct line of separation from the bedrock below.

The average nitrate value of the best material in the richer areas is low,

$ few of the carefully taken samples * * * carrying more than 5.25 per

cent of sodium nitrate. The total quantity of nitrate in the best of the areas

*^ studied is too small to justify the outlay of capital necessary for its com- 

^ mercial recovery.

In the present investigation eleven areas that had been reported to

** contain nitrate were examined, and six other areas that seemed likely 

« to contain nitrate were prospected. Nitrate was found in every area

but one of those reported to contain it. Danby Lake was barren.

Most of the deposits were of the clay-hill type but much poorer in 

if nitrate than the better deposits of the Amargosa region. Nitrate

was present in the clay surfaces of two playas, or " dry lakes." In

three areas it occurred as incrustations in protected situations in vol-

* canic rocks. At another place it was found in cavities in a peculiar 

deposit of gypsiferous travertine or gypsite. None of these deposits 

are commercially valuable. The evidence for this conclusion is 

stated in the body of this report.

PRESENT INVESTIGATION

In spite of the unfavorable findings of the Amargosa investigation it was recommended 4 that " scouting should be continued until 

all reported deposits in similar districts and the unexamined parts 

of some of the Amargosa fields have been tested sufficiently to disclose their character." So far as southern California is concerned 

this recommendation has been carried out. Soon after the Amargosa field parties disbanded in May, 1918 Hoyt S. Gale, who 

had been in general charge of the previous work, and the writer 

began the scouting mentioned. After June, 1918, the writer continued the work with one assistant.

The same general methods of exploration were employed in this 

work as in the earlier investigation.6 Long experience with the delicate " brown ring " reaction in the Amargosa region and frequent 

comparison with quantitative chemical determinations of samples of 

the same material sent to the chemical laboratory of the Geological 

Survey had made it possible to judge by the strength of the reaction 

whether more or less than 3 per cent of nitrate (as sodium nitrate) 

was present in the material tested. For example, a reaction rated 

" negative " indicated the absence of nitrate or at most only a trace; 

" weak," less than 1 per cent and more than 0.1 per cent; " fair," less 

than 2 per cent and more than 0.5 per cent; " good," less than 3 per 

cent and more than 1 per cent; and." strong," more than 3 per 

cent. These ratings are used throughout the present report. If more

4 Noble. L. F., and others, op. cit., p. 93. B Idem, pp. 15-17.
4 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

.4

than 3 per cent of nitrate was present little idea could be formed of 

the actual percentage, because the reaction usually became too violent * 

to preserve the brown ring. In general a reaction strong enough to > 

turn the solution black caused the liquid to boil violently, throw off 

brown fumes, and immediately thereafter become .transparent, '"* 

thereby indicating the presence of 5 per cent or more. It was never « 

possible to get a black boiling reaction from material containing less 

than 3 per cent of nitrate.

The checking by chemical analysis never showed a higher percent- > 

age of nitrate in a sample than the upper limit indicated by the rating of the field test, and in a few samples the percentage shown by 

analysis was much lower than the lower limit indicated by the rating. v 

(See p. 70.) So far as the ratings err, therefore, they err in overestimating the amount of nitrate present.

It is doubtful whether nitrate can be extracted profitably even from * 

large continuous areas of caliche containing 5 per cent of nitrate. 

Therefore ground containing less than 3 per cent is certainty not con> 

mercially valuable. These quantitative field tests, if carried out sys- V 

tematically and checked occasionally by quantitative chemical determinations in the laboratory, thus offer a practical, economical, and 

rapid method both for eliminating unpromising areas and for locat- v 

ing promising areas for more extensive sampling.

It was planned that if the field tests suggested that any areas were 

as promising as the better tracts of the Amargosa district, these areas * 

would be recommended at once for detailed investigation. No such 

areas were found. Because of the low percentage of nitrate indicated 

by most of the field tests, few samples were saved for quantitative ~< 

chemical determination in the laboratory, except enough in each area ^ 

to check the field tests and to complete the record.

In the following table the areas examined in 1918 and described < 

in this report are listed in the order of examination, together with a 

few localities subsequently tested. The locations of all areas but 

three (see figs. 5, 6, and 7), are given on Plate 1, which also shows * 

the location of areas in the Amargosa region described in the K 

previous report.
BARSTOW SYNCLINE 

Areas examined

5

No. on 

Plate 1 Region and name Character of deposit

Middle Mohave Desert, Calif.:

Barstow syncline. ......................

Coolgardie Lakes__ ...........................

Northern Mohave Desert, Calif.:

Pilot nitrate field.... ................................

Leach Lake_______________________

Owl Spring nitrate field ......................

Fish Lake Valley, Nov.: Tertiary beds (see flg. 7).____. 

Southern Mohave Desert, Calif.: Twenty-nine Palms __. 

Valley of Colorado River below Needles, Calif.:

West Well tract.........................................

Beal tract ... 

Vivet Eye tract..

Vidal tract........ ................................

Eastern Mohave Desert, Calif.: Danby Lake.. . 

Amargosa Valley, Calif.: Ratliff nitrate claims, near Shoshone. 

Peloncillo Mountains, Arlz.: Eberenz-Beach nitrate claims

near San Simon (see fig. 5). 

Animas Valley, N. Mex.: Hungerford nitrate claims (see

fig. 6).

Death Valley, Calif.: Tertiary beds on Furnace Creek . 

Valley of Virgin River, Nev.: Tertiary beds on Muddy

Creek.

Clay-hill caliche.

Clay surface of dry lake.

Clay-hill caliche.

Clay surface of dry lake.

Clay-hill caliche.

Do. «

Do.

Clay-hill caliche; Incrustations on 

volcanic rocks.

Clay-hill caliche.

Cavities in gypsite deposit overlying schist.

Clay-hill caliche.

Beds of rock salt and playa clay.

Clay-hill caliche.

Incrustations on volcanic rocks. 

Do.

Clay-hill caliche. 

Do.

These areas are irregularly distributed over a wide region where 

water is scarce. At the time of investigation most of them were 

a considerable distance from places where supplies could be had and 

were reached by roads that for the most part were poor and were 

little traveled. In recent years, however, travel in the desert has 

greatly increased, the main roads have become good, places where 

gasoline and supplies may be obtained are much more numerous, and 

in consequence most of the areas are now easily accessible.

MIDDLE AND NORTHERN MOHAVE DESERT

BARSTOW SYNCLINE

Mr. Gale and the writer discovered niter-bearing ground in the 

so-called Strontium Hills of the Barstow syncline (see pi. 1) while 

examining an area that was being prospected for strontianite by 

Mr. E. T. Hillis, of Barstow. Mr. Hillis joined in the examination.

The geologic features of the Strontium Hills have been described 

as follows: 6

The Strontium Hills are underlain by a series of lake and terrestrial depositswhich have been folded into a syncline. These beds have been partly described 

by Baker T under the name " Rosamond series " and later more fully by Pack.*

« Knopf, Adolph, Strontianite deposits near Barstow, Calif.: TJ. S. Geol. Survey Bull. 660, 

pp. 257-259, 1918.

7 Baker, C. A., Notes on the later Cenozoic history of the Mohave Desert region in 

southeastern California: California Univ. Dept. Geology Bull., vol. 6, pp. 842-347, 1911.

8 Pack, R. W., Reconnaissance of the Barstow-Kramer region, Calif.: U. S. Geol. Survey 

Bull. 541, pp. 141-151, 1913.
6 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

The syncline into which the beds have been bent is referred to by Baker and 

Pack as the Barstow syncline. A monograph on the fauna of the beds is in 

preparation [now published 8 ] by Prof. J. C. Merriam, who discusses also the 

age and correlation of the beds. The term " Barstow formation " is used by 

Merriam for the deposits containing the upper Miocene fauna and comprising 

the uppermost beds of the Barstow syncline, but it is recognized that this 

fauna may occur in all of the strata of the syncline. * * *

A threefold subdivision of the beds in the Strontium Hills may easily be 

recognized, as Pack has pointed out. The lowest member consists largely 

of granitic detritus* remarkably fresh in composition and consisting of angular 

boulders, some of which are as much as 5 feet in diameter. It is without more 

than a trace of bedding and is clearly an ancient alluvial deposit, a " fanglomerate." Some rhyolite tuff occurs with it. ,

The middle subdivision, which contains the strontium, is made up chiefly of 

grayish-green clay in thick beds. The erosion of the clay beds has produced a 

badland topography which is highly characteristic of the middle member of the 

Barstow syncline. At the surface the clay is loosely coherent, but in places it 

grades into shale, which is fairly well bedded. Crystals of gypsum half an 

inch or so in diameter are common throughout the clay beds. Moreover, the 

clay yields calcium sulphate on extraction with water, and it effervesces freely 

in hydrochloric acid; it is therefore a gypsiferous, calcareous clay. Calcareous 

concretions of odd and peculiar patterns are of widespread occurrence in the 

clay beds; they are locally called " fossils." . Above the clays come more highly indurated beds, consisting of calcareous 

tuffs, white rhyolite tuff, sandstone, and limestone in persistent beds 4 to 6 feet 

thick. Many of these limestones are clearly of algal origin, as shown by the 

concentric circular patterns on their weathered surfaces. * * *

The section described in the preceding paragraphs is that near the east end 

of the Barstow syncline, * * * where only the north limb of the syncline 

is exposed. Farther west the strontium deposits occur in the south limb of the 

syncline. The beds here resemble those of the middle subdivision, already 

described, but the interbedded algal limestones are especially conspicuous.

The borate-bearing beds of the near-by Calico district are probably equivalent 

to a part of the middle subdivision just described

The area which was then being prospected by Mr. Hillis for strontium is about 9 miles north of Barstow and is reached by a road 

that turns north from the Barstpw-Death Valley road at a point 

about 6 miles out of Barstow. It lies between altitudes of 3,000 and 

3,500 feet on the south limb of the Barstow syncline, nearly midway 

between the east and west ends of'the syncline.

The strata that crop out in this area are evidently those of the 

"j middle subdivision " described by Knopf. They consist of greenish shale, brown salty shale, fresh-water limestone, and some white 

ash or tuff. All the beds are steeply inclined. The shales resemble 

certain shales in the Saratoga and Confidence nitrate fields 10 (see pi. 

1), 50 to 60 miles northeast of the Barstow syncline, which contain

9 Merriam, J. C., Tertiary mammalian faunas of the Mohave Desert: California Univ. 

Dept. Geology Bull., vol. 11, pp. 437a-437e, 438-585, 1919. 

*> Noble, L. F., and others, op. cit, pp. 31 et seq., 52 et seq.
H BARSTOW SYNCLINE 7

^ salt, gypsum, and celestite, but in general they contain less saline ma-

* terial than the Saratoga and Confidence strata. Here, as in the Saratoga and Confidence fields, they are covered in many places by a saline 

clay soil that is practically barren of vegetation. Because of the

*r general resemblance of the ground to that in the areas in the Amargosa district known to contain deposits of niter-bearing caliche, a 

number of tracts of the greenish and brown shales were prospected

f by shallow pits.

The soil at the surface of the ground here consists of compact clay, 

in most places about 6 inches thick. The material in this layer gives 

no reaction for nitrate. Underneath the compact clay the soil is 

loose for a depth of 2 to 6 inches and contains large amounts of white 

efflorescent salts which appear to be chiefly sulphates of sodium and 

calcium. In places the material in this layer gives "weak" reactions for nitrate.

In the tracts underlain by greenish shale the shale just beneath 

the soil layers described is weathered and cracked, so that it crumbles 

into innumerable small flakes. These flakes are coated with films of 

transparent salt, largely sodium chloride. The zone of cracked shale, 

which is from 4 to 6 inches thick, occupies the position which the 

caliche layer occupies in the nitrate fields of the Amargosa district 

and grades downward into compact unaltered shale. Most of the 

material in the cracked zone gives " weak " to " fair " reactions for 

nitrate, but some of it gives " good " reactions. The unaltered shale 

beneath this zone gives "weak " reactions in some places but in gen-

* eral appears to be practically barren of nitrate.

In the tracts underlain by brown salty shale a hard, compact caliche is present in some places instead of the zone of cracked shale.

** This caliche is very similar to the hard caliche on the salty shales of 

the Saratoga and Confidence fields and consists largely of sodium 

chloride. It is about 4 inches thick and gives a weak reaction for

^ nitrate.

To check the field tests, three samples of material from the cracked 

zone on the greenish shale and one sample of the compact caliche on

^ the brown salty shale were saved for chemical determination. Two

, of the samples from the cracked zone, which gave "good" reactions

for nitrate in the field tests, contained 1.44 and 1.92 per cent of

V sodium nitrate; the other sample from this zone, which gave a 

"weak" reaction, contained 0.27 per cent. The sample of compact 

caliche from the brown salty shale, which gave a "weak" reaction,

* contained 0.40 per cent.

ft The amounts of nitrate indicated by these tests in the ground

examined are so low that the deposits are obviously of no commercial

^ value, but the occurrence itself is interesting because it shows that
8 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA ^ r

-A nitrate deposits of the clay-hill type are widely distributed in the 

desert region and are to be expected wherever any considerable areas 

of clay or shale formation crop out.

aeserc region ana are to be expected 

of clay or shale formation crop out.

 * 

>

^.--

The Barstow syncline is on the south side of a long flat ridge * 

whose crest is formed largely of granitic rocks. North of this ridge 

the land slopes into a wide basin known as Superior Valley, the 

lower part of which is filled with alluvial waste swept from the * 

surrounding hills. Its central floor ranges in altitude from 2,980 to ^ 

3,100 feet and is a gently sloping alluvial plain about 100 square 

miles in extent, which contains three small playas or "dry lakes" * 

known locally as the Coolgardie Lakes. (See pi. 1.) These dry 

lakes, which are shown on the Searles Lake topographic map, lie 

about a mile apart along an east-west line. Their surfaces are * 

smooth, compact clay, not markedly saline but barren of vegetation, 

and.do not differ in appearance from the surfaces of hundreds of 

similar playas in the desert region. The middle lake is crossed by V 

the road from Barstow to Granite Wells. (See pi. 2, (7.) It is the v 

smallest of the three and is about a mile wide.

The rocks in the hills about Superior Valley are practically all pre- ^ 

Tertiary granite or Tertiary volcanic rocks. The hills around the 

northern border of the valley, from Pilot Knob to the Eagle Crags, 

are carved from a thick series of lavas, breccias, and stratified tuffs * 

which rest upon granite. Elsewhere about the valley granite appears A 

to be the prevailing rock, though many hills consist of pink rhyolite 

or black lava. No clay strata like those with which the clay-hill '** 

nitrate deposits are commonly associated are exposed in the basin. + 

Shore markings or other deposits on the slopes about the valley floor 

to indicate that a lake of greater extent than the present playas ever ^ 

existed in the valley are lacking. ^

Because of the absence in the basin of any niter-bearing ground of 

the clay-hill type from which nitrate might be washed into the playas * 

by erosion it seemed worth while to test the clay surface of one of the ^ 

playas to get further evidence regarding the origin and distribution 

of nitrate in the region. Accordingly a point near the center of the ^ 

middle Coolgardie Lake was selected at random and a hole 3 feet y 

deep was dug. All the material taken from this hole was rather 

moist, fine clay which tasted salty but did not contain much visible * 

saline matter. The material from the surface gave no reaction for vnitrate; that a foot beneath the surface gave a " weak " reaction; and 

that 2 to 3 feet beneath the surface gave a " very weak " reaction. 

Evidently, therefore, none of the material contains as much as 1 per y, 

cent of sodium nitrate; indeed, probably all of it contains very much
4 LEACH POINT VALLEY 9

* Jess than 1 per cent, but the fact that the locality tested was selected

^ at random suggests that a small amount of nitrate is rather widely

distributed in the playa clay. The occurrence has no commercial

* value, but it is interesting as evidence that nitrate is accumulating in

V some playa clays in the desert at the present time. Possibly the

nitrate is being formed in the clay by the action of bacteria; but it

* is also conceivable that the nitrate is being washed into the playa by

P erosion. If it is being washed into the playa, the volcanic rocks in

and around the basin would appear to be a possible source, although

it is not known whether these rocks contain nitrate. Nitrate formed

* by bacterial action in soil supporting the sparse vegetation on slopes 

surrounding the playa might also be washed into it.

LEACH POINT VALLEY

* Pilot Knob and the Eagle Crags, north of Superior Valley, are 

parts of an irregular east-west range of low, broken mountains that

* extends from the vicinity of Pilot Knob eastward to the Avawatz

u Mountains, on the border of South Death Valley. Different parts of

this range have local names. The western portion, which includes

* Pilot Knob and the Eagle Crags, consists largely of lavas, tuffs, and 

l breccias of Tertiary age. The eastern portion, called the Granite

Mountains, consists almost wholly of granitic rocks.

North of and parallel with the range just described lies an east- 

^ west trough which is part of a chain of long irregular depressions

separated by low divides. This trough has been described briefly in 

% a previous report n and named the Leach Trough. 

4_ The part of the Leach Trough that lies just north of Pilot Knob

is known as Leach Point Valley.12 It is a long alluvium-filled de-

* pression which extends eastward from a point opposite Pilot Knob

^ to the divide in the trough at Leach Point. The Slate Kange lies

north of the western part .of the valley, and mountains that may

* be considered a southern extension of the Panamint Kange lie north

k of the eastern part. We§t of the Slate Range Leach Point Valley is

separated from the basin containing Searles Lake by a very low

divide across which a great lake that formerly occupied the Searles

^ Basin overflowed southward into Leach Point Valley and thence

eastward and northward into Panamint Valley.13 The middle por-

* tion of Leach Point Valley opens northward into Panamint Valley 

 through a narrow rocky gap between the Slate and Panamint

4 u Noble, L. F., The San Andreas rift and some other active faults in the desert region of 

southeastern California: Carnegie Inst. Washington Year Book 25, pp. 423, 424, 1926.

ii "Spurr, 3. B., Descriptive geology of Nevada south of the fortieth parallel and adjacent 

portions of California: U. S. Geol. Survey Bull. 208, p. 205, 1903. 

18 Gale, H. S., Salines in the Owens, Searles, and Panamint Basins, southeastern

* California: U. S. Geol. Survey Bull. 580, p. 312, 1914.
10 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

Ranges, and the entire valley drains northward into Panamint 

Valley through this gap.14

PILOT NITRATE FIELD 

LOCATION AND EXTENT

The Slate Range is terminated abruptly on the south by a fault 

along the northern border of Leach Point Valley that is believed 

to be a prolongation of the Garlock fault.15 North of the fault lie 

pre-Tertiary crystalline rocks schist, gneiss, and granite forming 

the southern part of the Slate Range. South of the fault, in a strip 

along the southern base of the range, is an area of light-colored 

bare hills which are rendered especially conspicuous by the pale, 

creamy tint of the barren clay soil that covers them. These clay 

hills mark the outcrops of upturned strata of Tertiary age and 

constitute the so-called Pilot nitrate field. (See pi. 1; also pi. 3, A.) 

The west end of the area is 6 miles south of the southeast end of 

Searles Lake and 15 miles southeast of Trona. From this point the 

outcrops of the strata extend eastward about 10 miles along the 

base of the Slate Range and disappear under the alluvium of the 

floor of Leach Point Valley at a point a mile southeast of the entrance to Panamint Valley. The width of the area does not exceed 

half a mile at most places, and the altitude ranges from 2,100 feet 

at the extreme east end to 3,500 feet or more in the middle portion 

along the flank of the Slate Range. The topography of the area 

is shown on the Searles Lake topographic map published by the 

Geological Survey.

PREVIOUS WORK

The Pilot nitrate field is described by Bailey 18 as follows:

The Pilot niter district is located on the old beach line east of Searles Lake, 

at the south end of the Slate Range. It takes its name from Pilot Peak [Pilot 

Knob], a famous landmark of the desert that is about 20 miles south of this 

district. [See pi. 2, A, B.] The locations are similar in general detail to 

those already described in Death Valley.

Searles Lake is the main depression, or sink, left by the evaporation of the 

ancient lake that once filled what is now known as the Panamint and Salt 

Wells Valleys, and whose terraces may be found 600 feet or more above the 

well-known borax lake. The local conditions were such that the beach lines 

of this great lake suffered more from erosion than did Death Valley, or more 

of the soft clay niter hills would be found around its margins.

14 For logs of roads see Thompson, D. G., Routes to desert watering places in the Mohave 

desert region, Calif.: U. S. Geol. Survey Water-Supply Paper 490-B, p^>. 172, 173, 183, 

1921. ......

15 Noble, L. F., op. cit, pp. 423, 424.

10 Bailey, G. E., The saline deposits of California: California State Min. Bur. Bull. 24, 

pp. 178, 179, 1902.
TT. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 1

INDEX MAP OF NITRATE FIELDS IN SOUTHEASTERN CALIFORNIA, SHOWING AREAS EXAMINED

C, Confidence; LC; Lower Canyon; S, Saratoga; UC, Upper Canyon; Z, ZabrisMe; 1, Barstow syncline; 2, Coolgardie Ls^;3.3E1Iot ' vl5l ° 7' T ^- Palms; ». West Well; 9, Beal; 10, Vivet Eye; 11, Yidal; 12, Danby Lake; 13, Bailiff claims;
U. S. GEOLOGICAL SURVEY BULLETIN N20 PLATE 2

A. PILOT KNOB FROM NORTHWEST

B. DIAGRAMMATIC SECTION OF PILOT KNOB

1, Rhyolite breccia, or tuff-breccia, 175 feet; 2, reddish tuff, 200 feet; 3, while tuff and ash, 110 

feet; 4, yellowish, greenish, and grayish tuff and ash, 120 feet.

C. COOLGAHDIE LAKE 

View north from middle of lake. Eagle Crags in background.
TJ. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 3

A. WEST END OF PILOT NITRATE FIELD

View north across Leach Point Valley, a, Outcrop of Tertiary strata ("niter hills"); h, Slate 

Range. Arrow indicates Searles Lake Basin.

K. LEACH LAKE

View east from point near middle, showing puffy character of ground. Avawalz Mountains in

background.

C. OWL SPRING

View southeast across embayment and down Owl Spring Wash. Arrow indicates the spring; 

T, Tertiary beds with nitrate. Avawatz Mountains in background.
PILOT NITRATE FIELD 11

Bailey's description gives the impression that the niter-bearing 

ground of the Pilot field is associated with the beach lines of the 

lake that formerly occupied the Searles Basin or with deposits laid 

down in that lake; but in fact the niter-bearing ground is associated 

with upturned strata of Tertiary age which are very much older 

than any beds that were deposited in the lake. Gale 17 has shown 

that the altitude of the maximum water line of the former Searles 

Lake could never have exceeded 2,264 feet, which is the altitude of 

the highest point in the old outlet channel through which the waters 

of the lake overflowed into Leach Point Valley and thence into 

Panamint Valley. All but a very small part of the Pilot field lies 

above this altitude.

Claims covering an area of about 20,000 acres are said to have been 

located in the Pilot field in 1909 by Walter Duisenberg, W. E. 

Lawton, and others, of San Francisco, and samples taken from the 

surface of the ground by the locators are said to have contained 

from 3 to 14 per cent of sodium nitrate.

EXPLORATION

The clay hills 3 miles north of the 2,270-foot (french mark on the 

Eandsburg-Death Valley road are characterized by specially large 

tracts of barren clay soil. The rocks underlying these hills strike 

east and are complexly folded along an axis parallel with Leach 

Point Valley and the fault along the Slate Range. The prevailing 

dips are nearly vertical. The hills are intricately dissected and are 

cut by deep canyons that cross the strike of the beds from north 

to south and open upon alluvial fans along the north margin of 

Leach Point Valley. In ascending one of these canyons to an altitude of about 3,300 feet the entire belt of clay hills was crossed. It 

was then recrossed by descending another canyon half a mile farther 

east. During this traverse the more promising-looking ground in 

the slopes and ridges of the clay hills on both sides of the canyons 

was. examined and tested. The area thus covered lies 2 miles east of 

the west end of the Pilot field and is believed to be fairly repre^ 

sentative of the middle and western portions of the field. (See pi. 

3, A.)

The strata nearest the valley, which here form the typical clay 

hills, are loosely consolidated cream-colored sandstones or very sandy 

clays which contain little saline material. Some of the beds contain 

a small amount of gypsum. The slopes of the hills are covered 

with a thick, loose soil whose surface is a crust of compact clay, but

"Gale, H. S., op. cit, p. 266. 

3201 31 2
12 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

no caliche was found beneath the soil. In places " weak " or " fair " 

reactions for nitrate were obtained in the loose soil just above the 

bedrock. No reactions indicated the presence of as much as 2 per 

cent of sodium nitrate.

The strata farther back from the valley, above most of the clayhill belt, are coarse sandy fanglomerates that contain a few beds of 

white volcanic ash. The relation of these f anglomerates to the sandstones and sandy clays of the clay hills was not determined. In the 

area examined the fanglomerates dip north, are less steeply inclined 

than the sandstones, and appear to be unconformable upon and 

younger than the sandstones, although they may be a part of the same 

series. They are certainly much older than the alluvial fans of 

the region. No reactions for nitrate were obtained in the ground 

underlain by the fanglomerates.

East of the area examined the sandstones and sandy clays with, 

which the niter-bearing clay soil is associated disappear under high 

detrital slopes and dissected f anglomerate along the northern border 

of Leach Point Valley, but they reappear several miles farther on 

and continue eastward to the east end of the field, southeast of the 

mouth of Panamint Valley.

An area near the^east end of the field, where the beds are crossed 

by the Ballarat road, was next explored. In this area the sandstones and sandy clays crop out in a strike valley north of a low

 ridge of fanglomerate. They contain more clay and more saline 

material than the beds in the area examined in the western part of 

the field. Many beds are creamy or greenish salty clay shales. In 

places a hard salty caliche was found on these shales just under the 

.surface clay soil. All the caliche observed within a distance of 1,000 

feet east and west of the road was tested, but no reactions for nitrate 

stronger than " fair " were obtained. In some places the shale just 

under the caliche gave " weak " reactions for nitrate. No caliche 

appears to be associated with the more sandy beds or with the 

f.anglomerates.

A number of prospect trenches, some of them several feet deep, 

iiave been dug in the ground just described, presumably by the men 

who located claims in the Pilot field in 1909. A layer of hard salty 

caliche 4 inches thick was seen in one trench, dug in moist greenish 

salty clay shale about 1,000 feet east of the road. This caliche had 

evidently formed since the trench was dug. No caliche could be

-found on the same shale bed in the undisturbed ground near the 

trench. Apparently the formation of this caliche is due to the exposure of moister bedrock by the trench. It gave no reaction for 

nitrate. A sample of it, saved for qualitative determination in the 

chemical laboratory of the Geological Survey, was reported to con-
LEACH LAKE 13

tain no nitrate and to consist largely of sodium chloride, together 

with considerable sodium sulphate and calcium sulphate.

CONCLUSIONS

Although but a small part of the Pilot field was explored the 

ground examined is believed to be fairly representative of the whole. 

In general, the strata in the western and middle parts of the field 

contain little saline material, and the conditions there are thus 

unfavorable to the formation of caliche. The strata in the eastern 

part of the field are more saline, and caliche has formed on them in 

places, but the best of this caliche thus far observed is poor in nitrate. None of the material tested in the Pilot field contained as 

much as 2 per cent of sodium nitrate. The possibility of finding 

areas of rich nitrate caliche in this field is therefore apparently 

remote. As the steep dip of the strata limits their outcrops to a 

narrow belt, and the saline shales with which the caliche is associated constitute only a part of these strata, the existence of large 

areas of caliche in the Pilot field is exceedingly improbable.

LEACH LAKE

Leach Lake, at an altitude of about 1,500 feet (barometric) lies 

about 8 miles east of the Leach Point divide, in an irregular 

alluvium-filled basin that measures about 15 miles from east to west 

and about 10 miles from north to south. The Leach Point divide 

forms a pass between the Quail Mountains and the Granite Mountains and constitutes the narrowest part of the Leach Trough. After 

crossing this divide the Randsburg-Death Valley road descends eastward in a dry wash nearly to Leach Lake, turns northeastward and 

skirts the north shore of the lake, then ascends a long, gentle detrital 

slope to the low divide between the Leach Lake Basin and the Owl 

Spring embayment, reaches Owl Spring Wash near Owl Spring, and 

descends the wash to South Death Valley. (See pi. 1.) Leach Lake 

may be easily reached from the road, a log of which is given by 

Thompson. 18

The basin of Leach Lake is typical of the smaller depressions in 

the desert region, whose drainage has no outlet to the sea. It is 

surrounded by ranges of bare, rocky mountains from which long, 

gentle alluvial slopes sweep down everywhere toward the central 

floor. These alluvial slopes consist of sand, clay, gravel, and disintegrated rock detrital materials washed from the mountains and 

spread out by intermittent floods. The materials become finer 

toward the base of the alluvial slopes until, near the central floor,

18 Thompson, D. G., op. cit., pp. 173, 203.
14 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

they consist chiefly of sand and clay. At places upon the slopes low 

rocky hills not yet buried by the alluvium project like islands. The 

lake is roughly circular in outline and about a mile wide. The 

surface consists of clay but differs somewhat from that of the Coolgardie Lakes, already described, in that it is rather uneven at places 

and has a curious rough, " puffy " appearance (see pi. 3, Z?), a feature which indicates that the clay contains more saline material than 

that of the Coolgardie Lakes. The alluvial slopes and parts of the 

sandy area bordering the lake support a scanty growth of desert 

shrubs, chiefly " creosote " (Covillea tridentata) , which grow far 

apart after the fashion of desert plants, but the surface of the lake 

is bare.

The rocks in the mountain slopes from which the alluvial filling 

of the basin is derived are mostly igneous chiefly pre-Tertiary 

granites. Tertiary volcanic rocks crop out at a few places. Metamorphosed sediments form a part of the Owl and Avawatz Kanges. 

Apparently no sedimentary rocks of Tertiary age crop out in the 

basin. A small area of the Tertiary strata that constitute the Owl 

Spring nitrate field is exposed on the low divide northeast of Leach 

Lake, but as most of the outcrops lie east of the divide it is unlikely 

that any appreciable quantity of material from this source has ever 

been washed into Leach Lake.

EXPLORATION

Leach Lake is said to have been sampled for nitrate by a Los 

Angeles mining engineer, who reported that the ground at a depth 

of a foot beneath the surface of the lake showed an average content 

of over 3 per cent nitrate, calculated as sodium nitrate. Three pits 

were dug by the Geological Survey party near the middle of the 

lake 100 yards apart and a little over 3 feet deep. At the surface 

at each pit is a layer of caked clay, one-half to 1 inch thick, which 

gave no reaction for nitrate. Beneath this is a layer of loose, granular puffy soil, 5 to 6 inches thick, filled with tiny elongated transparent crystals which are soluble and have a sharp, bitter, salty 

taste. This soil gave " fair" reactions for nitrate. Underneath 

the puffy soil is moist tough clay, which at a depth of 1^ feet gave 

" weak " to " fair " reactions for nitrate and at a depth of 2y2 feet 

gave " weak " reactions.

Samples of the puffy soil and the moist clay were saved from the 

pit in which the puffy soil gave the strongest reactions for nitrate 

and sent to the chemical laboratory of the Geological Survey for 

determination of the nitrate content and for general qualitative tests 

to determine the character of other salts present. The results of these 

determinations follow:
LEACH LAKE 

Tests of samples from Leach Lake

15

No.

of 

 sample

1008

inno

1010

Material

Puffy soil .

..-.do.... ..

Depth below 

surface

1 to 6 inches ...

1 to 2 feet.. ...

2 to 3 feetNitrate

as 

NaNOj

(per cent)

0.96

.44

.41

Largely NaCl,

MgCli.

Largely NaCl,

CaS04.

Other salts

CaClj, and small amounts 'of K

CaCh, and small amounts of K

0

and

and

It is of interest to compare these determinations with a similar

 qualitative determination of a sample of caliche from the Upper

 Canyon nitrate field of the Amargosa district, which was made at the 

same time in the chemical laboratory. This sample, collected by 

Mr. Gale and the writer, consisted of 50 pounds of caliche representing a strip 10 feet long between the 135 and 145 foot marks in trench 

T-12 on Bully Hill.19 The results of the determination follow: 

Sample 1025, 6 to 12 inches below surface; nitrate as NaN03 , 6.88 

per cent; total salts, 15.27 per cent; very little K; other salts largely 

NaCl, CaCl2, CaS04, and small amount of Mg. From this it appears 

that the salts associated with nitrate in the playa cjay at Leach 

Lake are practically the same as those associated with nitrate in the

 caliche at the typical clay-hill nitrate deposit of Bully Hill.

Leach Lake was revisited in October, 1918, to collect a sample of 

.soil from the niter-bearing ground for bacterial examination. (See 

p. 93.) Four pits 2 to 3 feet deep were dug in the surface of the 

lake in an area between the middle and the northwest shore, at 

intervals of 100 yards. The surface of the lake had been wet deeply 

by a heavy rain three weeks before. The material was moist and did 

not show so distinctly the layers noted in the former tests, when the 

ground was dry, but the layers were still recognizable. The material 

in all the pits gave " weak " to " fair " reactions for nitrate to a

 depth of about 1^2 feet and " weak " to " negative " reactions below 

that depth. A sample for bacterial examination was selected from 

material that gave the strongest field test for nitrate. This material 

was moist clay at a depth of a foot below the surf ace of the lake in 

one of the pits. (See pi. 3, B.) Another sample of the same material saved for determination of its nitrate content was reported by 

the chemical laboratory to contain 0.29 per cent of sodium nitrate.

CONCLUSIONS

The tests made at Leach Lake indicate that nitrate is widely 

distributed in the clay just under the surface of the lake but that the

18 Sec D. S. Geol. Survey Bull. 724, pi. 30, 1922.
16 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

amount is small, averaging less than 1 per cent. Evidently the 

amount diminishes below a depth of 1 to iy2 feet, but the tests did 

not go deeper than 3 feet. The deposit has no commercial value, but 

the occurrence, like that in the Coolgardie Lakes, is interesting because 

it shows that nitrate is accumulating in some playas at the present 

time.

OWL SPRING NITRATE FIELD

o 

LOCATION AND GENERAL GEOLOGIC FEATURES

From the low divide 2^ miles northeast of Leach Lake a broad 

valley descends eastward to South Death Valley and is followed by 

the Randsburg-Death Valley road. This valley, here called the Owl 

Spring embayment, is a wide alluvium-filled arm of the South Death 

Valley trough, similar in character to the embayments of Wingate 

Wash and Emigrant Wash, which enter Death Valley farther north. 

It is occupied by the shifting channels of Owl Spring Wash, a dry 

stream course that rises in the Owl Mountains north of the divide 

and enters South Death Valley at a point about 5 miles below Saratoga Springs. The Owl Spring embayment forms a rudely wedgeshaped depression pointing westward. The apex of the wedge is at 

the divide; the north side of the wedge is the Owl Mountains; the 

south side, the Avawatz Mountains; and the base, 'South Death 

Valley. The length of the embayment from its apex at the divide^ 

where the altitude is about 1,900 feet, to the floor of South Death 

Valley, where the altitude is about 150 feet, is 12 miles. The embayment is about 10 miles wide where it opens into South Death 

Valley but narrows westward to about 2 miles near the apex. The 

Owl Spring nitrate field lies along the channels of Owl Spring 

Wash and some of its small tributaries in the region about Owl 

Spring, at the west end of the embayment. (See pi. 1.)

Owl Spring (pi. 3, G) emerges along the north side of Owl Spring 

Wash at an altitude of about 1,750 feet. It is 10 miles west of 

the Saratoga nitrate field 20 (see pi. 1) and 15 miles south of the 

Confidence field. 21 It is about 45 miles by road from both Shoshone 

and Silver Lake, stations on the Tonopah & Tidewater Railroad, 

and about 65 miles from Kandsburg. 22

The floor of the Owl Spring embayment is a sloping plain built 

of deposits of alluvial material washed into the embayment from the 

bordering hills. Along the sides of the embayment the numerous 

coalescing alluvial fans form a continuous slope. In the axis of 

the embayment, along the channels of Owl Spring Wash, the deposits

20 Noble, L. F., and others, op. dt., pp. 31-51.

a ldem, pp. 51-59.

-2 For logs of these roads see Thompson, D. G., op. cit., pp. 198, 199, 202, 203.
OWL SPRING NITRATE FIELD 17

washed from the hills mingle with vast quantities of coarse gravely 

boulders, and sand brought down the wash by intermittent floods. 

In most of the wide lower part of the embayment these alluvial 

deposits conceal the rocks that underlie its floor, but toward the head 

of the embayment, in the vicinity of Owl Spring, the main wash and 

its tributaries have cut down their channels beneath the alluvial 

mantle, so that they expose narrow outcrops of the underlying rocks 

along their banks. In this dissected area, which extends eastward 

from the divide at the head of the embayment to a point about 2 

miles east of Owl Spring and covers perhaps 5 square miles, the 

underlying rocks thus exposed are upturned sedimentary beds of 

Tertiary age. The outcrops of some of these Tertiary beds which 

constitute the Owl Spring nitrate field are shown in Plate 3, 0.

The Tertiary sediments of the Owl Spring nitrate field are separated from the older limestone and granite of the Owl Mountains by 

a fault. This fault apparently continues eastward and forms theborder of the Owl Spring embayment northeast of the nitrate field. 

Between Denning Spring Wash and.Cave Spring Wash, at the east 

end of the southern border of the embayment, a magnificently exposed 

fault separates Tertiary beds lying in the embayment from the older 

rocks of the Avawatz Mountains. Apparently .this fault continues 

westward and borders the embayment on the south. The existence 

of outcrops of Tertiary beds projecting through the alluvial floor 

of the embayment at Eound Mountain and in the hills 4 miles southwest of Bound Mountain, coupled with the existence of outcrops of 

similar beds in the Owl Spring nitrate field, suggests very strongly 

that the entire embayment is underlain by Tertiary rocks. The 

embayment, therefore, would appear to be a structural depression 

underlain by Tertiary rocks and bounded by faults. Inasmuch as 

the Owl Spring embayment is nearly in line with the chain of depressions which includes the Leach Trough and which, farther to* 

the west, is associated with the Garlock fault, it is possible that the 

embayment represents a prolongation of that structural feature.

The Tertiary beds that constitute the Owl Spring nitrate field are 

complexly folded and are cut by numerous faults, so that'they dip 

in various directions. In some places the dips are very steep. A 

well-marked anticline whose axis trends northwest is exposed at 

one place, but in general the details of structure are difficult todetermine, because the beds are so largely concealed by the alluvial 

mantle that overlies them. It is evident, however, that the structure 

is very similar to that of the near-by Saratoga and Confidence fields.

The beds comprise saline and gypsiferous shales, sandstones, and 

limestones. The stratigraphic succession of the beds, like their 

structure, is difficult to determine, owing1 to the intense disturbance
18 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

that they have suffered and the iact that they are so largely concealed by the mantle of alluvium. In the banks of Owl Spring 

Wash just below Owl Spring are beds of curious gnarly or lumpy 

limestone, some of which are as much as 8 feet thick. Associated 

with the limestones are arkose conglomeratic sandstones similar to 

those exposed in the Amphitheater Canyon area of the Saratoga 

field.28 Southeast of the limestones and sandstones lies a belt of very 

.salty brown shales containing stringers of gypsum. These shales do 

not differ in any respect from the salty shales that form a large part 

of the Saratoga Hills area of the Saratoga field and there contain a 

bed of rock salt.24 Beyond the salty shales and apparently underlying them are clayey and sandy strata which contain large amounts 

of gypsum in thick beds and in stringers. Similar strata crop out 

northwest of Owl Spring for a mile or more along the banks of the 

.main wash that passes near the camp of the manganese mine operated 

.at that locality for a short tune during the war. These strata contain bed after bed of gypsum and, in some places, small crystals of

-celestite. They closely resemble strata in the Salt Basin area of the 

Saratoga field that contain large deposits of gypsum and celestite.26 

.North of the Randsburg road and west of Owl Spring, in an area 

.southwest of the wash that leads past the manganese camp, a number 

of washes afford more exposures of the Tertiary beds. Here also the 

beds comprise saline shales, sandstones, conglomerates, and limestones and contain large amounts of gypsum. They are succeeded 

on the northwest by a thick bed of greenish breccia composed largely 

of fragments of metadiabase. The relations of this bed were not 

determined, but it appears to overlie the other beds. All these beds 

,are overlain by coarse, poorly consolidated f anglomerate which makes 

high, grayish gravel hills northwest of the nitrate field and also 

.appears to cover much of the ridge that extends southeastward to 

the Avawatz Mountains from the divide at the head of the Owl 

.Spring embayment. This f anglomerate is only moderately tilted. 

It is apparently unconformable with the beds of the nitrate field 

and is therefore younger, but it is older than the alluvial material 

that fillsthe Owl Spring embayment and is probably of late Tertiary

 or early Quaternary age. Similar deposits of f anglomerate overlie ^, 

the Tertiary beds of the Saratoga, Confidence, and Upper Canyon , nitrate fields.28 ' v 

The occurrence of limestone, although not at all unusual in the < » 

Tertiary formations of the desert region, is perhaps tue most interesting feature of the Owl Spring nitrate field. In places the limestone forms beds as much as 10 feet thick. Some beds are full of *-

23 Noble, L; F., and others, op. cit, p. 38. . * Idem, p. 32. *

24 Idem, p. 33. so Idem, p. 35.
OWL SPRING NITRATE FIELD 19

hollow tubes, which probably represent plant stems. Many beds 

exhibit the characteristic structure of travertine. Some beds contain much siliceous material. In places beds of yellowish and buff 

shale are interstratified with the limestone. Limestones of this type, 

which are obviously of fresh-water origin, constitute a large part of 

the Horse Spring formation of southern Nevada, where they are 

associated with deposits of boron minerals (colemanite and ulexite) 

and magnesite.27 Similar limestones in the Mohave Desert near 

Bissell, Calif., are associated with strata containing deposits of 

magnesite.28 They also occur in Tertiary strata that contain borate 

deposits in the Furnace Creek, Shoshone, Kramer, and Calico districts. A large exposure of them was noted in a series of Tertiary 

beds that crops out near Tecopa Pass, on the western edge of 

Pahrump Valley. Another area of them has been observed in Wingate Wash, at the edge of Death Valley about 18 miles north of Owl 

Spring. Still another occurrence is in the Barstow syncline, where 

they are associated with beds containing deposits of strontianite.29 

In that locality the limestones appear to have been deposited through 

the agency of algae.

Aside from the limestones just described, which do not appear to 

be represented in the Saratoga nitrate field, the upturned Tertiary 

strata of the Owl Spring field are so much like those of the Saratoga, 

field in lithology that they are indistinguishable from them in appearance. Moreover, as already shown, there is good reason for 

believing that they are continuous with the strata of the Saratogafield beneath the alluvium that fills the Owl Spring embayment;. 

even if they are not continuous, the nearest outcrops of the strata 

of the Saratoga field are only 6 miles away. It is practically certain, 

therefore, that the strata of the Owl Spring and. Saratoga fields are 

the same series of rocks. It is not known what epoch of the Tertiary 

they represent, but it is probable that they are late Miocene or 

Pliocene.80

PREVIOUS WORK

The Owl Spring nitrate field was first explored in 1901 by Gilbert 

Bailey, who describes it as follows: 31

c

The Owl Spring nitrate field occupies the head of the valley between the' 

west end of the Avawatz Range and the east flank of the Owl Mountains. 

The district takes its name from the well-known "Owl Holes," or Owl

OT Noble, L. F., Colemanite In Clark County, Nev.: U. S. Geol. Survey Bull. 735, p. 28, 

1922.

28 Gale, H. S., Magnesite deposits in California and Nevada: U. S. Geol. Survey Bull. 540,. 

pp. 512-516, 1912.

a* Knopf, Adolph, op. cit, pp. 258, 259.

80 Noble, L. F., and others, op. cit, p. 35.

a Bailey, G. E., op. cit., pp. 177, 178.
20 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

Springs, that are located in about the center of the district. The locations 

selected here cover 6,080 acres.

The niter hills of this field are still partially covered by the Quaternary 

gravels, the top of the clay hills showing from 25 to 100 feet above the gravels 

in many places. As the field lies near the top of the divide, it has been more 

protected from erosion than the other fields. The southwestern or higher 

portion of the district is especially rich in colemanite and other borates, while 

the northeastern or lower portion is rich in large deposits of rock salt and 

heavy salt crusts. The caliche of this field, in general, is not so soft and 

friable as that of the other fields but carries sufficient salt to make the surface 

difficult to penetrate with a pick. In other respects the hills resemble the 

other districts.

In a summary of analyses of caliche from all the nitrate fields of 

the Amargosa district 32 Bailey gives the results of his sampling in 

the Owl Spring field as follows: "Highest per cent of niter, 67; 

lowest, 0.38; average of 18 analyses, 17.2 per cent." Each analysis 

is stated to represent a sample from a separate claim of 160 acres. 

The average nitrate content of the caliche in the Owl Spring field 

thus reported is far greater than that in any other field explored 

by Bailey, being nearly double that of the next best fields, the Sara- f 

toga and Upper Canyon, in which he reports the average nitrate , 

content as respectively 9.4 and 8.98 per cent.

A number of other parties have prospected the Owl Spring field. 

See particularly notes on the work of Olshausen, Chestnut, and 

Farrell, published in the report on the Amargosa region.83

The records given by the engineers cited are contradictory. The X 

high analyses reported by Bailey and Olshausen indicate that the v 

caliche in the Owl Spring field is the richest in California and suggest that the field is decidedly promising. On the other hand, the "* 

results obtained for the California Nitrate Development Co. by ^ 

Chestnut do not indicate that the field is particularly promising, 

even if much of the better ground reported by Chestnut should lie >* 

in the field. Finally, the low analyses of the samples taken by . 

Farrell indicate that the field is decidedly unpromising.

H4

EXPLORATION ,

Seven days were spent by the writer at different times from 1918 . 

to 1926 exploring and prospecting the Owl Spring field. In the 

course of this exploration, which amounted to a fairly thorough V 

reconnaissance, a careful traverse was made of all parts of the field. .^ 

First the representative types of ground were tested to learn what 

places contained nitrate. Then pits were dug in the more promising >v 

ground to a depth sufficient to penetrate into the underlying un^ 4

weathered bedrock, and all the material taken out of each pit was

 . __ *

33 Bailey, G. E., op. cit., p. 165.

88 Noble, L. F., and others, op. cit., pp. 11-14. ^4
OWL SPRING NITRATE FIELD 21

tested. In addition each outcropping set of beds in the bedrock 

strata that seemed at all likely to contain boron minerals or concentrations of nitrate was opened and tested. Field tests for boron were 

made by powdering the material, mixing it with a small amount of 

strong sulphuric acid in an iron spoon, adding alcohol to the mixture, and igniting it. If boron were present the flame would burn 

green at the end of the test.

It was found that the nitrate in the Owl Spring field is associated 

only with the outcrops of Tertiary strata, exactly as it is in the Saratoga, Confidence, Upper Canyon, and Lower Canyon.fields of the 

Amargosa region. As in these other fields, the outcrops of the strata 

on the gentler slopes are covered with a clay soil that is barren of 

vegetation. The layer of compact clay that forms the surface of 

the soil contains practically no nitrate. Beneath the compact surface layer at most places is a loose, powdery layer which contains a 

varying amount of white, efflorescent salts mixed with clay. These 

salts are largely sulphates and chlorides of sodium, lime, and magnesium. Only insignificant amounts of nitrate are present. Beneath this powdery layer and grading downward into the unaltered 

bedrock is a cemented layer, the caliche. This caliche is essentially 

the weathered upper portion of the bedrock (Tertiary strata) which 

has been recemented by various salts, chiefly sodium chloride. In 

other words, it represents a concentration of water-soluble salts in a 

zone below the leached soil at the surface and above the less pervious 

bedrock strata. The soluble salts appear to have been deposited in 

this situation by the evaporation of ground moisture, which brought 

them in solution to the surface, and the salts have been protected 

from being dissolved or washed away in surface water by the peculiarly impervious character assumed by the surface clay when it 

becomes wet.34 At most places in the field the caliche gives reactions for nitrate. At many places reactions indicating the presence 

of 0.1 to 3 per cent of sodium nitrate were obtained, but in all the 

field only one reaction that suggested more than 3 per cent. The 

distribution of nitrate in the caliche, moreover, proved to be exceedingly irregular. A " fair " or " good " reaction in one place would 

commonly be followed by a " weak " or " negative " reaction a few 

feet away. As in the other nitrate fields, the only significant 

amounts of nitrate proved to be in the caliche. The Tertiary strata 

upon which the caliche lies contain insignificant amounts at some 

places near the surface, but at most places they contain none at 

all. The gravelly beds of the washes that traverse the area, the 

alluvium that mantles it and fills the Owl Spring embayment, the

84 Noble, L. F., and others, op. cit., p. 70.
22 NITRATE DEPOSITS IN" SOUTHEASTERN CALIFORNIA

fanglomerates that overlie the upturned Tertiary beds, and the preTertiary rocks of the region are entirely barren of nitrate.

The Owl Spring field differs little in essential character from the 

Saratoga, Confidence, Upper Canyon, and Lower Canyon fields, in 

all of which the nitrate occurs in a blanket deposit, the caliche, 

which is associated only with the outcrops of upturned Tertiary 

strata. In general it resembles the Saratoga field more than it does 

the others, owing to the similarity of the strata. It differs from 

all these fields, however, in one very important respect. In the 

other fields the Tertiary strata with which the niter-bearing caliche 

is associated form hills which project above most of the alluvium 

that mantles slopes and fills depressions in the desert. Consequently 

areas in which caliche can occur cover a considerable part of these 

fields. In the Owl Spring field, however, the Tertiary strata are 

buried nearly everywhere under a mantle of alluvium and are exposed only along the washes that have cut their channels beneath 

the alluvial cover. (See pi. 3, G.) Consequently areas in which 

caliche can occur form only a small part of the field. For example, 

although the Owl Spring field covers more ground than the Saratoga Hills area of the Saratoga field, the extent of the niter-bearing 

ground in the Owl Spring field is only a small fraction of the extent 

of the niter-bearing ground in the Saratoga Hills. This fact alone 

is sufficient to condemn the Owl Spring field as a commercial source 

of nitrate, for the 1,200 acres of niter-bearing ground in the Saratoga Hills was regarded as too small an area to be worth consideration as a source of nitrate even under war conditions, unless it could 

be shown to be covered by a fairly continuous deposit of caliche 

averaging more than 5 per cent in nitrate content; 35 whereas the 

tests of the caliche in the Owl Spring field show that an average 

nitrate content as high as 3 per cent is not even a remote possibility.

Altogether, 58 tests for nitrate were made in different parts of 

the Owl Spring field, 11 in pits dug entirely through the caliche 

and the rest in holes dug well into the caliche. Of these 19 were 

" negative," 22 " weak," 11 " fair," 5 " good," and 1 " strong."

As in the Saratoga field, the hardest and thickest caliche was 

in the ground underlain by brown salty shales. This hard caliche 

consists chiefly of sodium chloride and at some places is at least 

12 inches thick, but it yields no reaction for nitrate. Apparently, 

like the similar caliche overlying the bed of rock salt in the Saratoga 

field,88 it is practically barren. The resemblance of the salt caliche 

just described to that overlying the bed of rock salt in the Saratoga 

field suggests that the salty shales in the Owl Spring field may

85 Noble, L. F., and others, op. cit., p. 50. 

38 Idem, p. 39.
OWL SPRING NITRATE FIELD 23

also contain one or more beds of rock salt, for the salt in the 

Saratoga caliche overlying the salt bed there is unquestionably! 

derived from the salt bed.

In the ground underlain by gypsiferous shales associated with 

the salty shales, a few small patches of caliche gave reactions for 

nitrate ranging from " fair " to " good."

In the ground underlain by the limestones and sandstones there was 

at some places a hard salty caliche ranging in thickness from 2 to 6 

inches. A number of " fair " reactions were obtained from this caliche, 

a few " good " reactions, and one that could be rated " strong." This 

very strong black boiling reaction was obtained in a patch of creamcolored caliche about 100 yards below Owl Spring, in ground on 

the northwest bank of the main Owl Spring Wash. A few feet 

on each side of this place the caliche gave only a " fair " reaction.

In all the Owl Spring field, as in the Saratoga field, not only is 

the nitrate irregularly distributed in the caliche but the caliche 

itself is discontinuous and patchy, large areas of the outcropping 

Tertiary strata being practically free from it. Owing to the fact 

that the preliminary testing of the Owl Spring and Saratoga fields 

was done in a similar way, it is possible to estimate the relative 

richness of the niter-bearing ground in the two fields with a reason- 

. able degree of assurance; the caliche in the Owl Spring field is very 

much poorer in nitrate than that in the Saratoga field.

The bedrock strata were tested for nitrate in all excavations dug 

through the caliche and at many places where no soil or caliche 

covers them. At most places beneath the caliche they gave no reaction for nitrate, but at some places they gave a " weak " reaction. 

The strata in the Owl Spring field dip steeply, and therefore the 

numerous washes that cut across their strike expose far thicker 

sections of them than would appear if the strata were horizontal. 

Many hundred feet of beds free from a cover of soil and caliche are 

thus displayed in low bluffs along the washes, where they afford 

excellent sections for testing and study. Many beds in these situations in all parts of the field were tested, but they yielded practically 

no nitrate. Very weak reactions were obtained at two or three 

places. In brief, here as in all the other nitrate fields, no evidence 

was found that the strata contain more than insignificant amounts 

of nitrate.

Exploration of the Owl Spring field by deep boring in the hope 

of encountering deeply buried concentrations of nitrate can not be 

recommended as practical, although, as stated in the report on 

the nitrate fields of the Amargosa region,87 where the question is

87 Noble, L. F., and others, op. clt., p. 20.
24 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

discussed further, boring in any of the fields would be of scientific 

interest and might yield results that could not be anticipated. But 

if such deep boring were contemplated it would seem wiser to Undertake the work in a field where the existence of considerable tracts 

of ground relatively rich in nitrate had been proved conclusively, 

as, for example, in the Upper Canyon field of the Amargosa region. 

In testing the strata for boron no reactions were obtained from 

the sandstones1 :or from the-salty shales. At a few places beds of 

limestone reacted to the test. Moreover, several samples of limestone sent to the chemical laboratory of the Geological Survey for 

analysis contained small percentages of boric acid, the maximum 

being about 0.25 per cent. From one sample made up of fragments 

chipped from shaly beds interstratified with the limestones both a 

reaction for boron and a " weak " reaction for nitrate were obtained. 

Other samples of similar material gave no reactions for boron. The 

best reaction for boron obtained in the Owl Spring field was in a 

lumpy calcareous bed about a foot thick consisting partly of shale 

and partly of nodules of calcareous material. This bed crops out in 

a wash "south of the Randsburg-Death Valley road about half a mile 

south of Owl Spring. The calcareous nodules gave reactions for 

boron, which were also obtained from the caliche in the district at 

two or three places. The samples of caliche that reacted for boron 

also reacted for nitrate. Colemanite and other boron minerals were 

searched for at many places in the strata but not found. Evidently 

Bailey's statement 38 that beds of colemanite crop out in the Owl 

Spring field is unwarranted. Yet the fact that the strata in places 

yield reactions for boron suggests that boron minerals may occur in 

them, and it.is possible,that:a more careful search may reveal their 

presence. At any rate, the field may be worth prospecting for boron 

minerals. At different times in the last 10 years a number of claims 

have been located for borax in the district, as is shown by notices 

posted on the claim monuments.

1. The nitrate in the Owl Spring field occurs in a layer of caliche 

averaging less than 5 inches thick that lies at most places less than 

a foot beneath the surface'of the ground. The caliche is associated 

only with the outcrops of upturned strata of Tertiary age.

2. The nitrate is irregularly distributed in the caliche, large tracts 

of the caliche being practically barren of nitrate.

3. The richer tracts of caliche are of small extent, generally not 

over a few feet in length.

3" Bailey, G. E., op. cit, pp. 177-178.
NITRATE NEAR TWENTY-NINE PALMS SPRINGS 25

4. The aggregate extent of all tracts of nitrate-bearing caliche in 

the field is not more than a few hundred acres.

5. The average nitrate content of the caliche is low, probably less 

than 1.5 per cent.

6. There is no evidence near the surface that the Tertiary strata 

with which the caliche is associated contain more than insignificant 

amounts of nitrate. It is therefore highly improbable that they contain valuable concentrations of nitrate at depth!,

7. For these reasons the Owl Spring field can not be regarded as 

of commercial importance as a source of nitrate.

8. Owing to the fact that some of the strata yield a reaction for 

boron it is conceivable that they contain deposits of colemanite or 

other boron minerals, although none have been found.

NITRATE NEAR TWENTY-NINE PALMS SPRINGS

REASON FOR INVESTIGATION

The occurrence of nitrate near Twenty-nine Palms Springs was 

brought to the attention of the War Department in 1917 by R. F. 

Kellam, of Los Angeles, in a letter to the Secretary of War announcing the discovery and asking for an investigation. The deposits were 

said to lie in Mud Hill (pi. 4, B, tf), a bare silt-covered hill 2 miles 

north of the springs, and to be covered by a group of claims held by 

Mr. Kellam and others. Mr. Kellam stated that he had submitted to a 

chemist a 50-pound sample consisting of a mixture of samples of 

the ground in the claims, " obtained by gathering material at a number of places, taking it just as it came, without distinction as to 

layers," and that the chemist had reported the sample to contain " 2 

per cent of sodium nitrate and 3 per cent of water-soluble potash." 

The Geological Survey was called upon to examine the deposits, and 

the writer spent three days in July, 1918, exploring them in company with John Waltenberg, assistant, and Mr. Kellam.

LOCATION AND GENERAL TOPOGRAPHIC FEATURES

Twenty-nine Palms Springs (see pi. 1) are in the southeastern 

part of a long, irregular depression in the southern Mohave Desert 

that has been named by Free 39 the Mesquite Trough. The Mesquite 

Trough lies just north of and parallel to the San Bernardino Range 

and extends from the valley of the Mohave River southeastward to 

Dale. Its length is over 100 miles, and its width at places is as much 

as 20 miles. It marks a part of the southern boundary of Mohave 

Desert, much as the Leach Trough marks a part of the northern

SB Free, E. E., The topographic features of the desert basins of the United States, with 

reference to the possible occurrence of potash : U. S. Dept. Agr. Bull. 54, pp. 45, 46, 1916.
26

boundary. Like the Leach Trough, it is probably of structura\ 

origin. The Mesquite Trough consists of a number of local basins 

separated by low alluvial divides, each basin independent and inclosed and each containing its typical dry lake, or play a. The basin 

at the extreme east end of the trough contains Dale Dry Lake. The 

basin next west of the Dale Basin contains Mesquite Dry Lake and 

two other small playas; Twenty-nine Palms Springs lie in the southern part of this local basin, about 6 miles south of the lake. Twentynine Palms Springs are most easily reached by a road that branches 

from the Los Angeles-Imperial Valley highway at a point 15 miles 

east of Banning, a town on the Southern Pacific Kailroad. (See 

pi. 1.) This road, which runs through Morongo Valley and crosses 

a low divide that separates the San Bernardino Mountains from 

their southeastern extension, the Little San Bernardino Mountains, 

is a good desert road. The distance over it to Twenty-nine Palms 

Springs from the point where it leaves the highway is 45 miles.40

The floor of the Mesquite Trough in the region about Twentynine Palms Springs is a nearly level to gently sloping plain composed of alluvial material washed from the bordering mountains 

and deposited in fans. Here and there in the plain a low hill projects above the alluvium. Plate 4, A, gives an idea of the character 

of the topography. Bordering this part of the Mesquite Trough 

on the north are the Bullion Mountains; on the south are the Little 

San Bernardino and Pinto Mountains, both forming a southeastward 

extension of the San Bernardino Mountains. The Little San Bernardino and Pinto Ranges are composed of pre-Tertiary crystalline rocks, chiefly granites and gneisses. Mesquite Dry Lake and 

two other playas on the floor of the trough lie in a chain along and 

parallel to the western base of a long, low spur of the Bullion Mountains that projects southeastward into the trough. On the south side 

of the trough, directly opposite this spur, a wide valley enters from 

the Pinto Mountains. At the mouth of the valley the alluvial material washed down is spread far out into the trough in a great fan. 

Across the nearly flat lower slopes of this fan, at a point about 2 

miles out from the base of the mountains, a thin straight line of 

trees runs east and west for a distance of a mile or more at right 

angles to the general northerly slope of the fan. (See pi. 4, A.)

The Twenty-nine Palms Springs emerge at intervals along this 

straight line, which is marked at most places by moist ground and, 

near its east end, by a low northward-facing escarpment in the 

alluvium. The fact that the escarpment trends at right angles to the 

general slope of the alluvial fan suggests that the escarpment may

*" For log of road and map see Brown, J. S., The Salton Sea region, California: U. S. 

Geo.l. Survey Water-Supply Paper 497, pp. 187-190, 1923.
XI. S. GEOLOGICAL StTEVEY BULLETIN 820 PLATE 4

A. VIEW SOUTH ACROSS MESQUITE TROUGH FROM MUD HILL 

Tertiary strata in foreground. Twenty-nine Palms Springs in right middle ground, indicated by arrow

IS. SOUTH SLOPE OF MUD HILL

View northwest along upper /.one of greenish elay beds, a, Greenish clay bed 20 feet thick; b, 

greenish clay bed 4 feet thick at base of zone. The dips of beds a and b appear to be divergent, 

owing to perspective, but are not, as may be seen from Figure 2.

C. PROSPECTING 20-FOOT BED IN MUD HILL

The bed is in the upper clay zone. Samples 1 and 2 were taken here. Center monument Palms

Claims No. 1 at right.

..Mr
IT. S. GEOLOGICAL SITRVEY BULLETIN 820 PLATE

A. GENERAL VIEW OF 400-ACRE AREA. 3 MILES WEST OF WEST WELL

a. Husal white chalky shale ovorlying eroded cryslallinc rocks; b .greenish clay shale; c, huff and yellowish shale with lenses of sand; d, alluvial caps, unconforniahle; X, locality where sample was taken

for field lest for nitrate.

B. UPPER BEDS OF BUFF SHALE IN 400-ACRE AREA

Arrow shows locality where sample West Well No. 4 was taken,

C. WEST WELL VIEWED NORTHEAST ACROSS CHEMEHUEVI WASH

Arrow indicates the well, a, Alluvium overlying lake-bed clays upon whose outcrop nitrate is 

found; b, Tertiary volcanic rocks containing "cave deposits" of nitrate; c, Chemehuevi Moun-
NITRATE NEAR TWENTY-NINE PALMS SPRINGS 27

not be an erosional feature but rather the topographic expression 

of a fault that has displaced the alluvium. The linear arrangement 

of the springs and their alinement with the escarpment also suggest 

the existence of a fault. A number of houses and a small stamp mill 

stood near the springs at the time of visit, and several tracts of land 

in the vicinity were being cultivated. Most of the trees along the 

line of springs are cottonwoods and mesquites; a few are figs. All 

afford grateful shade. A group of tall native palms (Washingtonia; 

see pi. 7, C] stands above the low escarpment just south of the 

easternmost springs. These palms arid the long line of green trees 

rising from the barren plain make Twenty-nine Palms Springs one 

of the most picturesque oases in the desert. Palms like these are 

an unfailing indication of ground water near the surface. Mesquite, 

shown at the right of the illustration, is another such indicator.

According to a barometric reading checked against a bench mark 

in Morongo Valley a few hours before reaching Twenty-nine Palms, 

the altitude at the springs is approximately 2,000 feet.

GENERAL GEOLOGY

The observer looking across the Mesquite Trough at Twenty-nine 

Palms Springs sees few features that break the monotony of the 

nearly level alluvial floor. The only features that are at all conspicuous are a low hill that projects above the alluvium a mile 

northwest of the springs and a group of low hummocky hills (pi. 

4, A) that project here and there above the alluvium 2 miles northeast of the springs and continue southeastward several miles toward 

the base of the Pinto Mountains. All these hills are composed of 

beds whose age is probably late Tertiary. Since the beds were laid 

down they have been tilted, faulted, and perhaps folded, and their 

upturned edges have been eroded into hills which are now all but 

buried by the alluvium washed into the trough from the bordering 

mountains. Altogether the hills cover an area of perhaps 3 or 4 

square miles, and the outcrops of the Tertiary beds in them cover 

probably less than 2 square miles. The structural relations between 

these strata and the pre-Tertiary rocks bordering the Mesquite 

Trough are unknown, because the contacts between the two series of 

rocks are concealed beneath the alluvium that fills the trough. Conceivably, however, the supposed fault in the alluvium at Twentynine Palms Springs marks a recent movement on the line of a concealed fault between these Tertiary strata and the pre-Tertiary 

granitic rocks of the mountains bordering the trough on the south.

The Kellam nitrate claims are in Mud Hill, one of the hills of 

upturned Tertiary strata just described. This hill lies 2 miles N.

3201 31 3
28 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

15° E. of Twenty-nine Palms Springs and is the northernmost hill 

in the group that extends southeastward toward the Pinto Mountains. Mud Hill is about a mile long and half a mile wide. The 

summit is 2,225 feet above sea level (barometric reading), or 225 

feet higher than Twenty-nine Palms Springs. The strata in the 

hill dip 25°-45° NE. and strike southeast. The axis of the hill is 

parallel with the strike of the strata.

Most of the strata exposed in Mud Hill are beds of loosely consolidated buff sandstone which here and there contain a lens of 

gravel, but at two horizons beds of greenish clay or shale are interstratified with the sandstones. The sandstones weather into a loose 

sandy or gravelly soil that covers all the lower slopes of the hill. 

In places the soil contains numerous fragments of gypsum, although 

very little gypsum was observed in the underlying strata. Some 

of the clay beds taste salty, but the sandstones are remarkably free 

from saline material.

Mud Hill

Upper greenish

SW

N.E.

Caliche layers containing sodium nitrate 

FIGURE 2. Diagrammatic cross section through Mud Hill, showing position

-, of upper and lower greenish clay zones and relation of nitrate-bearing 

caliche to their outcrop

The upper set of greenish clay beds may be called the upper clay 

zone and the lower set the lower clay zone. Figure 2 shows the 

position and relation of these two zones in Mud Hill. The upper 

clay zone crops out in a belt three-quarters of a mile long and not 

much over 100 feet wide along the south slope of the hill about 

midway up the slope. (See pi. 4, B.) Near the center monument 

of Palms claim No. 1 a clay bed at the top of the zone is 20 feet 

thick; below the clay bed lies 30 feet of sandstone, and below the 

sandstone a 4-foot clay bed from which sample No. 4 (see p. 31) 

was taken. Northwest of this locality otlier beds of clay appear in 

the zone and are separated by beds of sandstone, but none of them 

attain a thickness of more than 6 feet. Nowhere does the thickness 

of the entire upper clay zone exceed 100 feet. A few fragments of 

bone embedded in clay were found in digging a prospect pit in
NITRATE NEAE TWENTY-NINE PALMS SPRINGS 29

the uppermost clay bed near the center monument of the Palms claim 

No. 1. (See pi. 4, C.) These fragments are too poor for paleontologic determination, but they appear to be pieces of a limb bone of a 

small camel or horse. Although they afford no evidence concerning 

the exact age of the beds, they show conclusively that the beds are 

not pre-Tertiary and are not of marine origin. Probably the beds 

are of late Tertiary age. The amount of disturbance and erosion 

that they have suffered makes it improbable that they are younger 

than Tertiary. At any rate, the occurrence shows that the beds 

contain fossils and suggests that a systematic search in them for 

fossils would be worth while.

The lower clay zone is separated from the upper by about 300 

feet of sandstone. This lower zone crops out in a belt half a mile 

long and about 100 feet wide along the base of the south slope of 

the hill. The beds are not so well exposed as those of the upper 

zone, because they are covered at most places by soil and debris 

washed down the slopes of the hill. They resemble the beds of the 

upper zone but individually are thinner. The largest bed exposed is 

about 12 feet thick.

In general the strata in Mud Hill and in the other low hills 

near by resemble those of the Pilot nitrate field more than they do 

those of any other nitrate field described in the present report. In 

appearance and in degree of disturbance they are like the Tertiary 

beds that form the Indio Hills, in the Salton Sea region, 30 miles 

southwest of Twenty-nine Palms, and it is not unlikely that they 

are roughly equivalent to those beds in age.

EXPLORATION

From preliminary testing it was learned that reactions for nitrate 

could be obtained only in ground upon the outcrops of the beds of 

greenish clay in the upper and lower clay zones already described. 

If the nitrate were concentrated in a caliche layer, it could not possibly be commercially valuable unless the caliche were much thicker 

and richer than any previously found in California, because the total 

area of outcrop of the clay beds is too small, owing to the steep dip 

of the beds, to furnish any considerable tonnage of caliche. If, 

however, the clay beds themselves should contain significant amounts 

of nitrate, there was a remote chance of finding concentrations of 

nitrate in them that would be commercially valuable.

The clay beds were therefore prospected systematically by digging 

pits in the more promising ground along their outcrops, making the 

pits deep enough to penetrate the bedrock clay to depths of 2 feet 

or more. The results of this work showed that the deposits are not
30

essentially different from those in the Barstow syncline, Pilot, and 

Owl Spring fields, already described. The only significant amounts 

of nitrate occur in a caliche layer just beneath the surface soil.

Characteristically, the outcrop of each clay bed is marked by a 

layer of compact clay soil, barren of vegetation and from 1 to 3 

inches thick. The surface of the clay soil, as in all the other nitrate 

fields, is furrowed by innumerable small knobby corrugations, which 

give it a " cauliflower-like" appearance. This surface clay gives 

no reactions for nitrate. At places the clay is underlain by a loose 

powdery layer consisting of clay mixed with a varying amount of 

efflorescent saline material. This layer is from 4 to 6 inches thick 

and gives negative or only weak reactions for nitrate. Underneath 

the soil layers just described the bedrock clay is cracked and weathered to a depth of several inches and contains films of salt along the 

cracks. In places the cracked and weathered material is cemented 

into a compact hardpan, or caliche, by various salts, chiefly sodium 

chloride. The patches of caliche are very irregular, appearing or 

disappearing within distances of a few feet, and are thin, averaging 

perhaps 4 inches in thickness, although some patches reach 8 inches. 

At some places the caliche or the cracked layer corresponding to it 

give " good " reactions for nitrate, but at most places the reactions 

range from " weak" to " fair." Reactions differing greatly in 

strength were obtained within distances of a few inches, showing 

that the nitrate is irregularly distributed in the caliche. The bedrock clay strata beneath the caliche everywhere gave much weaker 

reactions than the caliche. At most places they gave no reaction 

at depths of 2 to 3 feet but at some places gave " weak " reactions. 

In general, therefore, they are either practically barren of nitrate 

or contain only insignificant amounts. Plate 4, #, (7, shows the 

general character of the nitrate-bearing ground.

The best reactions for nitrate were obtained in caliche overlying 

the 20-foot clay bed at the top of the upper clay zone, and the next 

best in caliche overlying the 4-foot clay bed at the base of the zone. 

None of the reactions were stronger than " good," and nearly all 

the better ones were only " fair," but in order to check the rating 

of the field tests a few samples were taken at places on the 20-foot 

bed and one sample on the 4-foot bed. These were sent to the laboratory of the Geological Survey for chemical determination. From 

the lower clay zone mostly " weak " or " negative " reactions were 

obtained and no reaction stronger than " fair." Therefore no 

samples from that zone were saved for chemical determination. A 

summary of the results of the sampling follows. By systematic 

mixing and division the original samples were reduced to half a 

pound each.
NITKATE NEAR TWENTY-NINE PALMS SP1UNG-S 31

Tests of samples from Mud Hill 

[Chemical determinations by E. T. Erickson]

No.

1 .......

2............

3... .........

4............

5... .........

6............

Thickness 

of layer 

represented

Inches 

18

6

8

6

6

24

Depth 

below 

surface

Inches 

12-30 6-12

8-16

5-11

5-11

12-36

Weight of 

original 

sample

Pounds 

35

K

3

5

3

5

Eeaction in field test of ground from 

which sample was taken

Weak.................................

Fair.....--. .... -------~-

....do.. ..............................

Nitrate 

as 

NaN03

Per cent 

0

.54

2.18

1 19

.60

.31

Soluble 

K

Per cent 

Trace.

Trace.

Trace.

0.15

1.42

Trace.

1. Greenish, clay, shale at center monument of Palms claim No. 1. (See pi. 4, 0.)

2. Cracked and weathered clay containing films of salt, overlying material represented 

by No. 1; corresponds to caliche layer.

3. Caliche 150 feet northwest of center monument of Palms claim No. 1.

4. Caliche 150 feet southeast of center monument of Palms claim No. 1.

5. Cracked and weathered clay containing films of salt, 600 feet southeast of center 

monument of Palms claim No. 1; corresponds to caliche layer.

6. Greenish clay shale underlying material represented by No. 5.

Samples 2, 3, 4, and 5 represent caliche and 1 and 6 represent the 

underlying unaltered bedrock. Samples 2, 3, and 5 are from the 

outcrop of the 20-foot clay bed. Sample 3, the most promising 

material found, represents the compact, thoroughly cemented type 

of caliche, and samples 2 and 5 the loose or flaky type, consisting of 

cracked fragments of clay separated by films of salt. Sample 4 

represents caliche of the flaky type from the outcrop of the 4-foot 

clay bed. The caliche represented by samples 3, 4, and 5 is overlain 

by a layer of loose powdery clay soil containing white efflorescent 

salts and small transparent crystals which have a bitter taste. The 

caliche represented by samples 4 and 5 grades imperceptibly into this 

overlying layer, a part of which is thus necessarily included in the 

samples, but the caliche represented by sample 3 is distinct from the 

overlying layer, and the sample consists of compact caliche alone. 

At the locality where sample 2 was taken the overlying loose layer 

is absent, and the caliche lies directly under the compact surface 

clay. According to Mr. Kellam, a large part of the material which 

made up his 50-pound composite sample of -the ground in his claims 

was obtained at the locality of samples 1 and 2.

From the results just given, it appears that the best caliche in Mud 

Hill contains considerably less than 3 per cent of sodium nitrate, 

that the caliche in general contains less than 1 per cent, and that the 

bedrock clay beneath the caliche contains only insignificant amounts.

Mud Hill constitutes perhaps one-sixth of the total area in which 

upturned Tertiary strata crop out in the Twenty-nine Palms region. 

Other outcrops appear in a hill a mile northwest of Twenty-nine 

Palms springs and in the tract of low hummocky hills that extend 

from Mud Hill southeastward to the base of the Pinto Mountains.
32 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

In all these areas the prevailing beds are nonsaline, loosely consoli* 

dated sandstones which neither contain nitrate nor are overlain by 

nitrate-bearing caliche. The clay beds, with which the nitrate deposits are associated, are much less abundant than the beds of sandstone.

CONCLUSIONS

1. The nitrate in the Twenty-nine Palms district occurs in a blanket 

deposit of so-called caliche less than 8 inches thick which lies 4 to 16 

inches below the surface of the ground.

2. The caliche is sharply restricted to outcrops of upturned beds 

of greenish clay.

3. The greenish clay below the caliche and the soil above the 

caliche contain insignificant amounts of nitrate.

4. The total area of outcrop of the greenish clay beds on which the 

nitrate-bearing caliche occurs does not exceed 12 acres in Mud Hill, 

the only locality where nitrate has been discovered in the district.

5. The distribution of the caliche is spotty.

6. The richest caliche obtainable contains less than 3 per cent of 

sodium nitrate, and the average probably contains less than 1 per 

cent.

7. Although other beds of clay similar to those in Mud Hill occur 

in the district their outcrops obviously can not cover a large area, 

owing to the steep dip of the beds.

8. For all these reasons the deposits of nitrate in the Twenty-nine 

Palms district afford no hope of commercial utilization.

9. The amounts of soluble potash found in the samples are not ; 

unusually high and are of no commercial importance. Like the

nitrate, the potash occurs in significant amounts only in the caliche. 

The scarcity of saline material in the Tertiary beds renders it highly 

improbable that concentrations of potash salts occur in them.

NITRATE IN VALLEY OF THE COLORADO RIVER

OCCURRENCES

Nitrate has been found at the following localities in the valley of 

the Colorado River below Needles, Calif.: In California, near Beal, 

6 miles southeast of Needles; near West Well, 33 miles southeast of 

Needles; near Vidal, 50 miles south of Needles; and near Vivet Eye 

Peak, 7 miles south of Vidal; in Arizona, 7 miles southeast of 

Parker.

The nitrate near Beal, Vidal, and Parker and most of that near 

West Well occurs a few inches beneath the surface of the ground 

in a salty layer at the base of clay soil underlain by strata composed 

largely of clay. These deposits resemble those in the Amargosa
NITRATE IN VALLEY OF THE COLOEADO RIVER 33

O

region 41 and those in the Barstow, Pilot, Owl Spring, and Twentynine Palms districts, described in the present report, and are of the 

" clay-hill" type.

Some of the nitrate near West Well, however, is associated with 

volcanic rocks, occurring mostly in crevices and on cliff faces protected by overhanging ledges. This deposit belongs to a class to 

which Gale 42 has applied the general term " cave deposits." Gale 48 

and Mansfield 44 have described many " cave deposits " in the western 

United States similar to the one associated with volcanic rocks near 

West Well. The nitrate deposit in volcanic rocks near San Simon, 

Ariz., described elsewhere in the present report, is similar to the 

deposit near West Well. Other deposits of this type in Presidio 

and Brewster Counties, in western Texas, have been examined by 

the Geological Survey.

The nitrate near Vivet Eye Peak occurs in cavities in a deposit 

of gypsiferous material like travertine and appears to constitute 

a type of deposit somewhat different from either the " clay-hill deposits " or the " cave deposits."

The West Well, Beal, Vidal, and Vivet Eye deposits are described 

below. Their locations are shown in Plate 1.

PREVIOUS EXPLORATION

Bailey 4B states:

Clay hills of considerable extent that carry niter in commercial quantities 

are reported as existing in the mountains on the west side of the Colorado River, 

about 30 miles south of the town of Needles. * * * Analyses of specimens 

brought in show from 14 to 40 per cent of niter in clay strata.

This locality is undoubtedly the clay-hill portion of the West Well 

tract.

In 1904 Turner 46 made a careful and systematic examination of 

the Beal, West Well, Parker, and Vivet Eye tracts, exploring the 

niter-bearing ground by digging or blasting pits and trenches in 

which he took samples at different depths for analysis. He outlines 

the general geologic sequence along Colorado Kiver below Needles as 

follows :

Soft lake beds (mostly horizontal).

Unconformity.

Volcanic rocks (chiefly tuff and breccia).

Older rocks.

41 Noble, L. P., and others, op. cit.

«Gale, H. S., Nitrate deposits: U. S. Geol. Survey Bull. 523, p. 9, 1912,

48 Idem, pp. 16-25.

44 Mansfield, O. R., Nitrate deposits in southern Idaho and eastern Oregon: U. S. Qeol. 

Survey Bull. 620, pp. 19-44, 1915.

« Bailey, G. E., op. cit., p. 180.

48 Turner, H. W., The sodium nitrate deposits of the Colorado: Min. and Sci. Press, vol. 

«4, pp. 634-635, 1907.
34 TITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

He then states:

The nitrates were found in three forms:

1. Efflorescence, chiefly on porous volcanic breccias, West Well area. In protected places on volcanic rocks patches of white salts were found to contain 

sodium nitrate up to 1.5 per cent, with much sodium chloride. It. required but 

a few blasts, however, to demonstrate that the deposits were a mere surface 

efflorescence, as a foot or two below the rock contained only traces.

2. In the shales of the lake beds. In the Beal area, near West Well, and 

south of Parker, as well as at many other points, there are extensive layers 

of greenish shale in the lake beds, and these shales. nearly always give a reaction for sodium nitrate.

The beds are much cut up by gulches, and the surface is usually crusted 

over with a mud formed by the slacking of the shale during rains. This crust 

(A) usually gives a reaction for nitrates and other salts, but immediately under it there is frequently a white layer (B) richer in soda and lime salts. 

Frequently layer (B) is wanting. Finally, resting on the undisturbed shale, 

is a third layer (G) from 3 to 12 inches thick, composed of broken bits of shale, 

and this lower layer usually shows a strong reaction for- sodium nitrate.

If now we cut through these surface deposits into the undisturbed underlying shale, we find usually a sudden decrease in the content of salts and conclude that the larger content of salts in the surface layers is due to leaching 

by the rain water from the shale, which breaks and slacks when wet. These 

salts are then redeposited immediately undet the mud crust in layers (B) and 

(C).

3. Deposits on the hill slopes associated with other salts and travertine, Vivet 

Eye. * * * In ascending [the Riverside Mountains in the vicinity of Vivet 

Eye Peak] from Colorado River, one passes first over limestone and dolomite 

beds probably of Paleozoic age; next over a series of green schists; then comes 

the limestone that forms the summit of Vivet Eye. These three terraneshave a general north-south strike and dip at a steep angle.

The zone of green schist is largely obscured by fragments of schist that have 

been cemented by a porous deposit of carbonate of lime resembling travertine, 

mixed with varying amounts of white salts. This travertine material, evidently of recent origin, is 20 feet or more thick in some places.

A number of cuts were made in the cement breccia of Vivet Eye, and here 

also the content of sodium nitrate was found rapidly to diminish with depth. 

At some points, however, nearly pure deposits of white salts, a foot or more 

thick, were observed, and subsequent analyses showed several salts were 

pre&ent. In one sample as high as 14.4 per cent sodium nitrate was found.

Only one of the many samples that Turner took from the clayhill deposits that is, the deposits " in the shales of the lake beds " 

was found to contain as much as 4 per cent of sodium nitrate, and 

only two other samples as much as 3 per cent.

Turner concluded that none of the three types of deposit are commercially valuable. His analyses of the samples from type 1 (the 

cave deposits), in which the nitrate occurs as "efflorescence chiefly 

on porous volcanic breccias," and from type 2 (the clay-hill deposits), in which the nitrate occurs "in the shales of the lake beds," 

indicate that the amount of nitrate in these deposits is prevailingly 

low; whereas the rapid decrease of nitrate with depth in every exca-
NITEATE IN VALLEY OF THE COLORADO RIVER 35

vation indicates that the deposits are superficial. Some samples from 

the Vivet Eye deposit (type 3) are relatively rich in nitrate, but the 

excavations dug in this deposit indicate that it also is superficial. 

However, Turner regarded the Vivet Eye deposit as the most promising of all the deposits that he examined.

Turner's report, like a report by Frank Bobbins on the nitrate 

deposits of the Upper and Lower Canyon fields in the Amargosa 

region,47 which was made in the same year (1907), records a fair, 

thorough, and conscientious attempt to ascertain the extent and value 

of typical clay-hill nitrate deposits by systematic prospecting and 

sampling. Like Robbins's report, it gives a clear and accurate account of the mode of occurrence of the nitrate and is in close accord 

with the observations made later by the Geological Survey in the 

same ground.

In 1910 Graeff,48 gave analyses of four samples which he took 

from the surface of clay beds that crop out in clay hills 100 to 300 feet 

high in Chemehuevi Valley, 32.6 miles south of Needles. This locality is undoubtedly within the West Well tract and in all probability 

lies within that part of the tract that is designated the 400-acre area 

in the present report. The analyses show 7.2, 8.2, 17.2, and 22.6 per 

cent of sodium nitrate. These remarkably high percentages of 

nitrate in the surface samples led Graeff to conclude that the interior of the clay hills contains large deposits of nitrate. As evidence 

in support of this conclusion he states that one surface sample taken 

near the top of a hill contains 8.2 per cent of sodium nitrate, whereas 

another surface sample taken 14 feet lower down on the same hill 

contains 22.6 per cent. However, as he states that he did not penetrate the interior 'of the hills nor obtain samples from strata under 

their base, it is evident that all his samples represent surface 

material.

REASON FOB INVESTIGATION

In 1917, after the United States had entered the World War, 

interest in nitrate revived, and many tracts of niter-bearing ground 

in the desert region were again actively prospected. In the Colorado 

River Valley interest centered in the deposits near West Well, and 

many claims were staked there. Some of the locators wrote to the 

War and Interior Departments stating that valuable deposits of 

nitrate had been discovered and asking for an investigation of the 

deposits. One deposit that was said to cover 15,000 to 20,000 acres 

in the vicinity of West Well was said to have yielded samples containing as high as 15 per cent of sodium nitrate. Another deposit 

near West Well was said to form a bed many hundred acres in extent

" Noble, L. F., and others, op. cit., p. 12.

« Graeff, F. W., Eng. and Min. Jour., vol. 90, p. 173, 1910.
36 NITRATE DEPOSITS IK SOUTHEASTERN CALIFORNIA

containing 4.87 per cent of calcium nitrate. Clay strata at some 

places were said to have yielded samples containing as high as 20 

per cent of sodium nitrate. Notwithstanding these optimistic 

reports concerning the discoveries, it is probable that in ordinary 

times the Geological Survey would not have undertaken an investigation of the deposits, for Turner's careful and systematic examination 

had demonstrated beyond a reasonable doubt the superficial character 

of the deposits and their prevailing low nitrate content. Indeed, 

the mode of occurrence alone, as outlined by Turner, would indicate 

that the deposits are valueless, even if some patches of ground contained a fairly high percentage of nitrate. However, the emergency 

created by the war made it imperative to overlook no clue to the 

existence of even possibly workable deposits.

PLAN AND RESULTS OF INVESTIGATION

In planning the investigation it was decided to examine one representative tract of each of the three types of deposit described by 

Turner, prospecting the ground by digging pits deep enough to 

penetrate the unweathered bedrock beneath the deposit and testing 

the material removed. If systematic field testing showed that any 

deposits in these representative tracts offered hope of commercial 

utilization all tracts of the sort in the region were to be prospected 

and sampled, but if the representative tracts proved unpromising a 

brief reconnaissance of the other tracts would suffice. The West 

Well and Vivet Eye tracts were selected for the more detailed 

exploration the West Well tract because it contains all the promising discoveries reported to the War and Interior Departmentsr 

because it contains deposits of both the " cave " arid the " clay-hill n 

type, and because it contains larger areas of clay-hill ground than 

the other tracts; the Vivet Eye tract because it contains the unusual 

type of deposit that Turner regarded the most promising of all the 

Colorado Kiver deposits.

Beginning in August, 1918, seven days was spent exploring the 

West Well tract, part of a day was devoted to the Beal tract, five 

days to the Vivet Eye tract, and one day to a tract near Vidal.

In the West Well tract considerable areas of clay-hill ground 

contain nitrate concentrated in a layer less than 6 inches thick a 

few inches below the surface. The content of nitrate in the caliche 

layer is low, averaging certainly less than 2 per cent and probably 

less than 1 per cent, and the bedrock 6 inches below the caliche 

contains no nitrate or only traces. The nitrate is very irregularly 

distributed in the caliche, and the caliche itself is patchy in distribution, being present at some places and absent at others. In 

volcanic rocks near West Well some protected surfaces under cliffs
NITRATE IN VALLEY OF THE COLORADO RIVER 37

and some cavities in the rock contain nitrate, but this nitrate is only 

a surface efflorescence. Field tests of the best material obtained 

from these deposits indicated a nitrate content of less than 2 per 

cent. Both the clay-hill deposits and the deposits in volcanic rocks 

are therefore of very low grade, superficial, and consequently of no 

commercial value. There is no tract of niter-bearing ground covering, as was reported, 15,000 to 20,000 acres anywhere in the region. 

The largest single tract of niter-bearing ground does not exceed a 

few hundred acres in extent, and the area of all the niter-bearing 

ground in the West Well tract is measurable in hundreds of acres, 

not thousands. The deposit said to form a bed containing 4.87 per 

cent of calcium nitrate proved to be a bed of calcareous marl containing no nitrate or only traces, although patches of caliche upon 

some outcrops of the bed contain small amounts of nitrate.

The nitrate-bearing ground of the Vivet Eye tract is a peculiar 

surface deposit of loose or partly consolidated material averaging 3 

feet in thickness which overlies steeply inclined beds of schist. The 

character and origin of this surface deposit are not clear. It somewhat resembles travertine but appears to be composed chiefly of 

gypsum, not calcium carbonate. In general it suggests certain 

gypsum deposits of the efflorescent type to which Hess 49 has applied 

the term "gypsite." It is therefore called gypsite in the present 

report. The gypsite is perforated by numerous small cavi'des, most 

of which contain deposits of white powdery saline material, largely 

sulphates of sodium, calcium, potassium, and magnesium, and some 

of the saline material contains as much as 12.70 per cent of sodium 

nitrate. Most of the cavities are only a few feet in diameter, and 

their aggregate extent is small in comparison with the mass of the 

gypsite, which is nearly barren of nitrate; moreover, the nitrate 

content of the saline material in the cavities varies widely. Perhaps 

a few tons of nitrate could be produced from the Vivet Eye tract by 

collecting the saline material from all the more readily accessible 

cavities, but the distribution of the nitrate is so spotty and the 

amount contained in the gypsite as a whole is so small that the tract 

is of no commercial importance. The schist beneath the gypsite 

contains no nitrate.

The Beal and Vidal tracts proved to be clay-hill tracts like the 

West Well tract but smaller. Here also the nitrate occurs in a 

caliche layer a few inches below the surface. The caliche is patchy 

and spotty. No ground was observed better than that in the West 

Well tract, which is poor.

In brief, the results of the Geological Survey's investigation are 

practically the same as those obtained by Turner and confirm his

48 Hess, F. Ei., Ai reconnaissance of the gypsum deposits of California: U. S.' Geol. 

Survey Bull. 413, pp. 7-22, 1910.
38 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

conclusion that none of the Colorado River deposits are commercially valuable.

Detailed descriptions of the localities and of the deposits upon 

which the conclusions just stated are based follow.

WEST WELL TRACT 

LOCATION AND EXTENT

Chemehuevi Basin, the broad irregular depression bordered by 

the Mohave, Sacramento, Turtle, and Whipple Mountains, is drained 

by a dry stream course known as Chemehuevi Wash, which enters 

the Colorado River in Chemehuevi Valley. .(See pi. 1.) About 5 

miles west of the river Chemehuevi Wash cuts through a group of 

low rocky hills that rise across its path on the floor of the basin. Just 

upstream from these hills a well, known as West Well, has been dug 

in a sandy flat bordering the wash. (See pi. 5, (7.) To reach West 

Well from Needles the traveler must turn east from the NeedlesParker road at a point 27 miles from Needles and follow a road thai 

leads to the well. The distance by road from Needles to West Well 

is a little over 33 miles.50

The niter-bearing ground that constitutes the West Well tract 

lies along Chemehuevi Wash between West Well and the Colorado 

River and is wholly within T. 4 N., Rs. 24 and 25 E. Nearly all 

of it is south of Chemehuevi Wash, and most of it is within the 

part of T. 4 N., R. 24 E., that lies east of a line drawn south through 

West Well. The area of the entire tract is about 36 square miles.

GENERAL GEOLOGIC FEATURES

Most of the surface of the tract is covered with a mantle of 

alluvium forming broad, gently sloping plains which rise from 

Chemehuevi Wash and the Colorado River to the bedrock slopes of 

the Mohave and Whipple Mountains. (See pi. 5, C.} Numerous 

stream courses, the largest of which 0 is Chemehuevi Wash, have cut 

deep channels in the alluvium, so that most of the tract is a monotonous succession of gently sloping mesa-like surfaces and steep-sided 

gullies. As exposed in the sides of the gullies the alluvium ranges 

in thickness from 3 to 50 feet. Over some areas it has been worn 

entirely away.

Underneath the alluvial mantle lie strata of the lake-bed series 

and older rocks of Tertiary and pre-Tertiary age. In the higher 

parts of the tract the lake-bed strata are either covered entirely by 

the alluvium or crop out only in bluffs along the deeper gullies, but 

in the lower parts, where the gullies widen out and where much

60 For log of road see Thompson. D. G., op. cit., p. 240.
WEST WELL TRACT 3$

of the alluvium has been removed by erosion, they are exposed over 

considerable areas and are carved into clay hills or badlands. (See 

pi. 5, A, B.) At some places in the tract low rocky hills of the 

older rocks project above the lake-bed series and the alluvium. (See 

pi. 5, C.) The largest of these hills form the group that rises across 

the path of Chemehuevi Wash just east of West Well. They consist chiefly of volcanic rocks of Tertiary age rhyolite, breccia, and 

tuff but partly of quartzite and gneiss that are much older than 

the Tertiary volcanic rocks.

By rough estimate, the alluvium covers 29 of the 36 square miles 

in the West Well tract, the outcrops of the lake-bed series cover 

2 square miles, and the outcrops of the older rocks 5 square miles.

AREAS CONTAINING NITRATE

The clay-hill nitrate deposits are associated with the outcrops of 

the lake-bed series, and the " cave deposits" are associated with 

the outcrops of the Tertiary volcanic rocks. The alluvium containsno nitrate.

The largest continuous exposure of the lake-bed strata in the? 

West Well tract lies about 3 miles east of West Well and occupies 

roughly the SE. % sec. 11, the SW. % sec. 12, and the E. i/2 sec. 14, 

T. 4 N., R. 24 E., covering in all about 400 acres. (See pi. 5, A, B.) 

This exposure may be called the 400-acre area. Some fairly large 

exposures, none of which appear to be as large as the 400-acre area,. 

occur in sees. T, IT, and 18, T. 4 N., E. 25 E. All other exposures in 

the tract are narrow, disconnected outcrops in bluffs along the sides 

of gullies. Altogether the outcrops outside the 400-acre area cover 

perhaps 850 acres, but no single outcrop is more than a few acresin extent.

The low rocky hills that border Chemehuevi Wash just east of 

West Well occupy sees. 9 and 15, the S. % sec, 4, the SW. % sec. 10-,. 

the N. 1/2 sec. 16, and the W. i/2 sec. 14, T. 4 N., R. 24 E., and cover 

about 2,400 acres.

Sees. 1 to 4, 8 to IT, and 20 to 23, T. 4 N., R. 24 E., were traversed 

and explored. These sections include the 400-acre area and practically all the disconnected outcrops of the lake-bed strata, as well 

as most outcrops of the Tertiary volcanic rocks. They contain all 

the ground in the West Well tract in which discoveries of nitrate? 

have been reported.

CLAY-HILL DEPOSITS 

METHOD OF EXPLORATION

At first preliminary tests were made at many different places on> 

the outcrops of the -lake-bed strata to locate the more promising 

ground. Then the ground where the strongest reactions for nitrate-
40 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

had been obtained was prospected by pits dug 1 to 3 feet deep, and 

the different layers of material removed were sampled. The pits 

were deep enough to penetrate 6 inches to 2 feet into the unaltered 

bedrock below the surface soil. Each sample taken from the pits 

was obtained by systematically mixing and dividing not less than 5 

pounds of material.

More than 100 preliminary tests were made, but only 37 were sufficiently promising to justify digging pits for systematic sampling. 

In all, 81 samples from the 37 pits were tested in the field, but no 

sample furnished a reaction indicating the presence of more than 

3 per cent of sodium nitrate. Therefore it was not considered worth 

while to save many samples for analysis in the chemical laboratory of 

the Geological Survey. A few that gave "weak" reactions were, 

however, sent to the laboratory to check the first tests. Upon analysis they were found to contain only traces of nitrate.

The 400-acre area was more thoroughly explored than the other 

outcrops of the lake-bed strata, both because it is larger and because 

it exhibits a thicker section of the strata than any other area in the 

West Well tract. Of the 37 pits 19 were dug in this area, and more 

than half of all the samples were taken there.

THE 400-ACRE AREA

\

Areal geology. The rocks consist chiefly of strata of the lake-bed 

series that crop out continuously in steep slopes along the sides of 

the valley and its tributary gullies. (See pi. 5, A, B.) At most 

places the strata are carved into badlands, but here and there they 

are worn into smooth rounded hills, some of which stand within 

the valley. These hills are mantled with a light-colored clay soil 

that supports no vegetation and are similar to the clay hills of other 

nitrate districts described in this report. Except where they are 

so steep as to form bluffs, the badland slopes are likewise covered 

with the characteristic barren clay soil. Along the rim of the valley 

the alluvium overlies the lake-bed strata in a continuous mantle, 

and within the valley isolated remnants of the alluvium cap some 

of the higher clay hills. (See pi. 5, A.} The floor of the valley is 

covered with gravel and sand washed down the stream courses by 

intermittent floods.

The base of the lake-bed series is well exposed in the southern part 

of the area. The strata lie upon an uneven surface composed partly 

of Tertiary lavas, largely rhyolite, and partly of pre-Tertiary 

metamorphic rocks, largely quartzite and gneiss. Here and there 

these older rocks project through the lowermost lake beds, and at 

places, remnants of the basal lake beds fill small hollows in the older 

rocks; 
WEST WELL TRACT 41

The basal layer of the lake-bed series is a coarse sandy conglomerate made up of fragments of the underlying rocks. The 

fragments as a rule are derived from whatever type of rock immediately underlies the conglomerate. For example, where the 

conglomerate rests upon Tertiary lavas the fragments are composed 

of rhyolite and rhyolite breccia; where it rests upon pre-Tertiary 

metamorphic rocks the fragments are composed of quartzite, gneiss, 

and pegmatite. The conglomerate varies considerably in thickness, 

ranging from 15 feet to the vanishing point. Over considerable 

areas it is absent.

Overlying the conglomerate is a bed of brilliantly white loosetextured shale that ranges in thickness from 15 to 50 feet. (See 

pi. 5, A.) In the field this shale was thought to be very fine volcanic 

ash, but a specimen of it sent to the chemical laboratory of the 

Geological Survey for determination proved to consist largely of 

calcium carbonate and was classified as a calcareous marl, or chalk. 

This shale is the bed that was reported to contain 4.87 per cent of 

calcium nitrate (pp. 35-36).

Above the white shale is greenish shale 25 to 50 feet thick which 

is more or less gypsiferous and very thinly laminated, many laminae 

being as thin as cardboard. (See pis. 5, A, and 6, A.) This shale 

passes up into light yellowish-brown or buff shale which here and 

there contains lenses of sandjr material. Both the greenish shale 

and the buff shale contain a considerable amount of sodium chloride. 

The greatest thickness of the buff shale as exposed in the area is 175 

feet. It is overlain unconformably by the alluvium, so that its thickness as originally deposited is unknown.

The strata just described, which constitute the lake-bed series, 

dip very gently or are horizontal in the 400-acre area, but at some 

places near by they dip steeply in various directions and are cut by 

faults. One of these places is about a mile to the southwest, in the 

upper valley of the main wash that traverses the area.

Most of the alluvium overlying the lake-bed strata consists of 

poorly assorted sand^ gravel, and clay that obviously have been 

washed from the mountains surrounding Chemehuevi Basin and 

spread out in alluvial fans. (See pi. 5, O.)- In places, however, 

beds of sorted and well-rounded cobbles lie upon the lake-bed strata, 

and, although some of these cobble beds are 200 feet or more above 

the Colorado River, it is impossible to escape the conclusion that 

they have been deposited by the river, for many of the cobbles are 

identifiable with rocks that' crop out along the river many miles 

above Chemehuevi Valley. One cobble bed, shown in Plate 7, #, 

contains fragments that appear to be lithologically identical with 

certain beds of Cambrian quartzite (Tapeats sandstone) and Car-
42 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

boniferous limestone (Redwall limestone) of the Grand Canyon 

region.

The stratigraphic sequence of the deposits just described is summarized in the following table:

Section of formations exposed in the J/OO-acrc area

Feet

Sand and gravel, tilling beds of washes____________ (?) 

Undifferentiated alluvium, consisting chiefly of mountain 

outwash deposited in alluvial fans, but partly of river . 

deposits_________.,_____________________ 0-50

Unconformity.

Lake-bed series:

4. Buff clay shale containing a few sandy beds _ +175 

3. Greenish clay shale_____________ ____ 25-50 

2. White chalky shale________________1____ 15-50 

1. Conglomerate__________________________ 0-15

+290

Unconformity.

Volcanic rocks, largely rhyolite and rhyolite breccia___ (?) 

Unconformity. 

Quartzite, quartz schist, granitic gneiss, and pegmatite__ (?)

Mode of occurrence of nitrate. The. soil that mantles the outcrops of the shales of the lake-bed series commonly exhibits two 

distinct layers an upper layer of compact material, which forms 

the surface of the ground, and an underlying layer of loose, powdery 

material. (See pi. 9, G.) At some places the powdery layer is 

absent. The upper layer consists of compact clay whose surface is 

corrugated by innumerable little knobs and cracks and is 1 to 3 

inches thick. (See pis. 6, B, and 9, C.) At most places it gives no 

reaction for nitrate, but at some places it gives a very weak reaction. 

The underlying loose layer consists of powdery clay mixed with white 

efflorescent salts chiefly sulphates and chlorides of sodium, potassium, calcium, and magnesium. This layer is commonly less than 

12 inches thick. Generally it gives weak reactions for nitrate.

Ordinarily the shale beneath the soil mantle just described is 

cracked, weathered, and more or less cemented by saline material to 

a depth of 2 .to 12 inches. The saline material occurs far more 

abundantly in this weathered zone than in the soil above it or in the 

unweathered shale below it, consists chiefly of sodium chloride, and 

at some places gives fair to good reactions for nitrate. As a rule the 

shale beneath the weathered zone gives no reaction for nitrate, but 

at some places it gives a weak reaction. Thus here, as in the other 

clay-hill tracts described in this report, the only significant amounts 

of nitrate occur in a weathered and more or less cemented zone cor-
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 6

A. GREENISH LAKE-BED SHALE IN CIIEMEHUEVI WASH

Shows thin lamination.

B. PROSPECTING GREENISH CLAY SHALK li\ CHEMKHljKVl WASH, 1H MILES

NORTHEAST OF WEST WELL 

Nitrate-bearing ground free from vegetation.
II. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE

<£ (. ' *&& ' ^ " ,. .:>

A. FAULTED AND ERODED STRATA OF LAKE-RED SERIES (a) OVERLAIN RY

ALLUVIUM (b)

b, Typical exposure in bluffs along lower Chemehuevi Wash; X, locality where sample that gave 

nitrate reaction was obtained at depth of 1 foot.

R. RIVER-WORN COBBLKS LYING UPON LAKE-BED SERIES MORE THAN 200 

FEET ABOVE COLORADO RIVER

C. TWENTY-NINE PALMS 

Note low escarpment. Palms like these are unfailing indicators of ground water near the surface.
TJ. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE

.<» V ' 

'' >r ..

A. GYPSITE DEPOSIT ON EAST SLOPE OF RIVERSIDE PEAK 

a, Gypsite deposit lying on schist,; h, limestone; c, Riverside Peak.

U. \1IC\\ .NORTHEAST ALONG (iYPSITE BELT 

Colorado River at right, a, Gypsite belt; b, limestone.
TI. S. GEOLOGICAL SURVEY 

.\. \K\II \IK\\ OF GYPSITI; ]>Ki>osiT

Shows cavernous surface and honeycomb structure, 

a, Nitrate-bearing cavity.

B. PROSPECT IN GYPSITE 

X, Schist.
WEST WELL Tit ACT 43

responding to the caliche layer of the more promising clay-hill tracts 

of the Amargosa region. 51 As in the other clay-hill tracts described 

in the present report, only a small part of the material in this zone 

forms true caliche. Most of it is loose .and flaky, crumbles into small 

fragments when dug, and resembles the " pie-crust" caliche 52 of the 

Amargosa fields, but at some places it is tightly cemented and resembles the harder, compact caliche 53 of those fields. In general, 

however, even the best material is much poorer in nitrate than the 

average material obtained in the Saratoga and Upper Canyon fields 

of the Amargosa region.

Exploration. The outcrops of the four subdivisions of the lakebed series in the 400-acre area were prospected, first by preliminary 

tests at many different places to determine what ground contained 

nitrate, then by digging pits and taking samples in the ground where 

the best reactions for nitrate were obtained. The tests were distributed vertically across the outcrops as well as horizontally along 

them, in order to cover the beds of each subdivision in vertical 

sequence as well as along the strike. The results of this exploration 

may be summarized as follows:

No nitrate is associated with the conglomerate at the base of the 

lake beds, and very little is associated with the white chalky shale 

that overlies the conglomerate. (See p. 41.) This white shale contains little soluble saline material and at most places gives no reaction for nitrate, but at some places near the surface it gives a very 

weak reaction. The clay soil that covers the shale is barren of nitrate, 

but here and there the cracked surface of the shale just under the soil 

contains a small amount of soluble salts and gives a " \feak " reaction 

for nitrate. However, no reaction was obtained anywhere that indicated the presence of more than 1 per cent of nitrate, and it is 

therefore inconceivable that any considerable amount of calcium 

nitrate is associated with the bed, as reported.

Most of the nitrate in the 400-acre area is associated with the outcrops of the greenish shale and the buff shale. (See p. 41 and pis. 

5, A, B, and 6, A.) "Good" reactions for nitrate were obtained 

from the greenish shale at some places in the cracked and more or 

less cemented caliche zone just under the soil layer, but generally 

the reactions were " weak" or only " fair." The unaltered shale 

beneath the caliche zone gave everywhere either " very weak" or 

" negative " reactions: Six pits were dug in the greenish shale at 

different places where the best reactions were obtained. Of the 

samples thus taken two from the caliche zone gave " good " reactions,

51 Noble, L. F., and others, op. cit., p. 7. 

82 Idem, pp. 69, 70. 

53 Idem, p. 37.

3201 31 4
44 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

two " fair," and two " weak." The best of the " good " reactions 

did not indicate the presence of as much as 3 per cent of sodium 

nitrate. Samples of unaltered shale from depths of 2 to 3 feet in 

four pits gave "negative" reactions, and samples in two pits gave 

" weak " reactions.

The buff shale, which overlies the greenish shale and constitutes the uppermost subdivision of the lake-bed series in the 400- 

acre area, is thicker than all the other subdivisions together and 

underlies at least three-fourths of the typical clay-hill ground in 

the area, all the larger clay hills being carved from it. The buff 

shale yielded " fair" reactions for nitrate in the caliche zone at 

most places and " good" reactions at some places. Bedrock at 

depths of a few inches to 2 feet below the caliche zone gave " very 

weak " or " negative " reactions. Thirteen pits were dug in ground 

where the best preliminary tests were obtained. Six of the pits 

were distributed over about an acre of ground on slopes bordering 

a low gap in clay hills between the main stream course traversing 

the 400-acre area and the largest tributary wash entering this 

stream course from the west. The pits were dug at different stratigraphic levels in the lower 100 feet of the buff shale. This locality, 

as nearly as could be determined, is in the NE. % SE. % sec. 11, T. 

4 N., R. 24 E. The other seven pits were distributed over about 2 

acres of ground on steep slopes just north of the tributary wash 

mentioned and were dug at different stratigraphic levels in the 

upper 75 feet of the buff shale. (See pi. 5, B.) This locality is a 

little over a quarter of a mile northwest of the first locality and 

is approximately in the center of sec. 11.

Of the samples taken in the six pits dug in the lower 100 feet of 

the buff shale, two from the caliche zone gave " good " reactions and 

four " fair "; one sample of the unaltered shale at a depth of 16 

inches below the caliche zone gave a " weak" reaction, and five 

samples at depths between 1 and 3 feet gave " negative " reactions. 

Plate 9, C, shows one of the pits in which a " good " reaction was 

obtained in the caliche zone and illustrates the prevailing character of the niter-bearing ground in the clay-hill areas of the West 

Well tract.

Of the samples taken in the seven pits dug in the upper 75 feet 

of the buff shale, four gave " fair " reactions, two " negative," and 

one "good." The material that gave the "good" reaction is a 

compact caliche, 4 to 8 inches thick, in which the chief cementing 

salt is sodium chloride. The deposit is of small extent, however, 

covering less than half an acre. A few other small patches of 

this material occur in the vicinity, but at most places, as elsewhere
WEST WELL TJRAOT 45

in the 400-acre area, the caliche zone consists of loose fragments of 

cracked shale mixed with a small amount of saline material; the salts 

fill tiny cracks in the shale and coat the fragments in thin films 

but are not so abundant as to cement the shale into a compact 

mass. Samples of the unaltered shale at depths of 2 feet beneath 

the caliche zone in all pits gave " negative " reactions.

Both the buff shale and the underlying greenish shale contain 

some saline material, most of which is sodium chloride, and some 

beds contain more than others. At many places the soil that mantles 

the shale contains small pieces of gypsum. Probably the gypsum 

occurs in tiny stringers in the shale. The buff shale contains many 

lenses of sandy material. Curiously, the patches of hard salty 

caliche appear to be associated with these sandy beds rather than with 

the finer beds of saline clay shale.

OTHER AEEAS

The clay-hill deposits in other parts of the West Well tract do 

not differ materially from those in the 400-acre area just described, 

the nitrate occurring in a cracked and more or less saline layer on 

outcrops of strata of the lake-bed series; but because the lake beds in 

these other parts of the tract are covered nearly everywhere with 

alluvium and crop out only along the sides of the deeper washes, the 

patches of niter-bearing ground are narrow, discontinuous, and 

individually of small extent, although in the aggregate their area 

greatly exceeds that of the niter-bearing ground in the 400-acre area. 

Accordingly the deposits could not be commercially valuable even 

if they were very much richer in nitrate than those in the 400-acre 

area proved to be. Nevertheless, it seemed worth while to explore 

them systematically in order to learn whether there was any basis 

for the statements that valuable amounts of nitrate occur beneath 

the caliche zone in the lake beds themselves.

At most places in these other parts of the West Well tract the 

strata with which the clay-hill deposits are associated are lithologically identical with the lake beds that crop out in the 400-acre area 

and are readily identifiable with one or more of the four subdivisions 

occurring in that area. At some places, however, they differ somewhat from the strata already described. For example, a series of 

beds exposed about half a mile south of the 400-acre area, in the 

N. y2 sec. 23, T. 4 N., E. 24 E., consists of layers of greenish clay shale 

averaging less than a foot in thickness alternating with layers of 

brown, loosely consolidated sandstone 1 to 5 feet thick. These beds 

are not identifiable with any of the four subdivisions in the 400-acre 

area, because they consist predominantly of sandy material. More-
46 NITRATE DEPOSITS IN SOUTHEASTERN" CALIFORNIA

over, unlike the beds in the 400-acre area, they dip steeply in different 

directions and are cut by faults. Their relations to the beds in the 

400-acre area are difficult to determine, because they are not in contact 

with them, but it seems probable that they are a part of the same 

series. The shale interbedded with the sandstone is indistinguishable 

lithologically from much of that in the greenish shale and buff shale 

of the 400-acre area. Probably, therefore, the alternating beds of 

shale and sandstone overlie the buff shale and represent a transition 

from clayey to sandy deposits at the top. of that subdivision. The 

fact that the upper part of the buff shale in the 400-acre area contains 

lenses of sandstone lends support to this inference.

Prospecting of the niter-bearing ground yielded practically the 

same results as in the 400-acre area. At most places the surface soil 

gave " negative " reactions and at some places " weak " reactions, but 

in general it proved to be barren of nitrate. Locally the material in 

the caliche zone gave " good " reactions, but as a rule the reactions 

were " fair " or " weak." As in all other clay-hill districts explored, 

this zone proved to be the only horizon at which significant amounts 

of nitrate occur. Everywhere below the caliche zone the unaltered 

strata at a depth of a few inches gave " negative " or only " very 

weak " reactions, and although many tests were made at different 

places no evidence was found that any stratum contains more than 

an insignificant amount of nitrate.

In all, 18 pits were dug at places where the best reactions were 

obtained during the preliminary testing. Only four of these pits 

yielded samples that gave " good" reactions, all taken from the 

caliche zone. No reaction indicated the presence of more than 3 per 

cent of sodium nitrate. The following table shows the approximate 

location of these four pits and the character of the ground at each 

locality.

Pits sampled in T. 4 N., R. 24 E., West Well tract

1. E. V> NE. ^4 sec. 17_________ Greenish clay shale equivalent to subdivision 3 of the 400-acre area.

2. E. % SW. % sec. 16________- Beds of greenish and buff clay shale a

few inches to a foot thick, alternating with beds of loose sandstone 1 

to 5 feet thick.

3. SW. Vt NE. % sec. 10 (see pi. 6, 7*)_ Greenish clay shale equivalent to subdivision 3 of the 400-acre area.

4. SE. 1,4 NE. ^4 sec. 21________ Buff clay shale.

The following record of pit 2 is typical of the other three pits and, 

indeed, represents fairly the character of the best clay-hill nitrate 

deposits in the West Well tract.
WEST WELL TEACT 47 

Results of sampling in pit 2

Material sampled

Cracked, flaky shale containing considerable saline material (caliche zone) 

Depth 

below 

surface 

(inches)

0-2

2-6

6-9 

9-30

Reaction for 

nitrate

"Negative.*' "Weak."

"Good." 

"Weak."

The pit was dug in one of the shale layers in a series of alternating beds of shale and sandstone. In a near-by pit dug in one of 

the sandstone layers the material in the caliche zone gave a " weak " 

reaction for nitrate and the sandstone under the caliche zone gave 

a " negative " reaction.

As in the 400-acre area, the nitrate in all the ground explored 

proved to be associated chiefly with outcrops of greenish or buff, 

more or less saline clay shale, for the most part equivalent to subdivisions 3 and 4 of that area. Comparatively little nitrate was 

found with the white chalky shale equivalent to-subdivision 2.

About half a mile southeast of West Well, near the southern border of the hills of volcanic rock, prospectors have dug pits at several 

places in the white shale, some of them 6 feet wide and 4 to 5 feet 

deep. Several of the deeper pits were cleaned out and a number 

of other pits were dug in the vicinity during the present investigation, but no reactions for nitrate stronger than " weak " were obtained either in the shale itself or in the soil overlying it. Exploration of the white shale at other places in the West Well tract yielded 

no more promising results.

DEPOSITS ASSOCIATED WITH VOLCANIC ROCKS

A small amount of nitrate is associated with the outcrops of the 

volcanic rocks in the group of low hills just east of West Well, composed partly of volcanic rocks of Tertiary age and partly of older 

rocks. The volcanic rocks crop out in bold ledges, in places forming 

precipitous cliffs, and many of them exhibit the cavernous structure 

common in rhyolitic lava and breccia, so that small caves or shallow 

alcoves protected from the weather by overhanging ledges are abundant. Most of the nitrate occurs in these protected situations..

The hills cover about 3 square miles and rise several hundred feet 

a.bove the general level of the alluvial deposits on the floor of 

Chemehuevi Basin, which entirely surround them. (See pi. 5, 0.) 

At some places along the base of the hills, particularly along their 

southern margin, strata of the lake-bed series, chiefly the white 

chalky shale and the greenish shale, crop out, beneath the alluvium.
48 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

Chemehuevi Wash crosses the hills in a canyon cut in the volcanic 

rocks. Probably at one time the hills were buried by the lake 

beds; otherwise it is difficult to explain why the stream has cut 

its channel directly through these hills, composed of resistant rocks, 

instead of around them through the much more easily eroded lake 

beds and alluvium. Apparently the stream established its present 

course before erosion had removed any considerable part of the 

lake beds and, remaining in this course down to the present time, cutthrough the hills as they were gradually exhumed.

An area in the southwestern part of the hills covering approximately the N. 1/2 sec. 16, T. 4 N., K. 24 E., appears to have been 

prospected more thoroughly than any other part of the West Well 

tract. In this area, which lies just east of West Well, beds of 

greenish tuff and breccia and flows of pinkish rhyolite are the 

most conspicuous members of the volcanic series. Much of the tuff 

is well stratified and resembles coarse sandstone. In one good 

exposure it dips at an angle of about 30° and is overlain by a flow 

of rhyolite. At some places a bed of whitish compact siliceous 

material, whose character was not determined but which appears to 

be either a fine-grained silicified rhyolitic ash or an altered rhyolite, 

is associated with the rhyolite and tuff. Common features of many 

of these rocks are cavernous structure and the presence of a considerable amount of opalescent silica, or chalcedony. Many outcrops 

of the greenish tuff and some outcrops of weathered rhyolite are 

covered with clay soil that resembles the soil on the niter-bearing 

ground in the clay-hill deposits. Pits 2 to 3 feet deep have been 

dug at many places in the soil on these outcrops and were still 

fairly fresh at the time of examination. In the present test several 

of these pits were deepened and others dug in the vioinity. The 

results were no more encouraging than those obtained in the niterbearing ground associated with the lake beds. At most places the 

weathered tuff or rhyolite just under the surface soil contains considerable saline material, which corresponds to the caliche in the 

clay-hill deposits and, as in those deposits, is at the most only a 

few inches thick. It passes down into unaltered bedrock that appears 

to contain practically no soluble salts. Only " weak " or " negative " 

reactions for nitrate were obtained in the soil, " weak " or " fair" 

reactions in the saline zone, and " negative " reactions in the underlying bedrock. No reaction at any place was strong enough to 

justify systematic prospecting and sampling of the ground.

Many small caves and alcoves in rhyolite, breccia, and tuff were 

examined here and in other parts of the volcanic hills. The surface 

of the rock in some of these protected situations is covered with a 

whitish efflorescence, and for an inch or two beneath the surface the
VIVET EYE TRACT 49

rock is more or less disintegrated and tastes salty. This surface material yielded reactions for nitrate ranging from " weak " to " fair," 

but no reaction strong enough to justify systematic sampling. 

Pieces of the fresh rock an inch or two under the surface everywhere 

gave "negative" reactions. The patches of niter-bearing material 

are not abundant and are of small extent, most of them being only a 

few feet wide and less than an inch thick. They are obviously superficial, because they do not extend into the. mass of the rock. These 

" cave " deposits would be commercially valuable only if large masses 

of the rock were impregnated with nitrate, whereas the tests show 

that the surface material contains only insignificant amounts and indicate that the fresh rock either is practically barren or at best contains very little.

Many " cave " deposits in the western United States similar to those 

near West Well have been explored in the hope that the rock under 

or behind the deposits might prove to be impregnated with valuable 

amounts of nitrate. The results of this wq§k have invariably been 

disappointing. The surface showings of nitrate at the West Well 

deposits do not compare favorably with those at the more promising 

" cave " deposits elsewhere, so that, unless one of the more promising deposits can be shown to be commercially valuable, it would 

seem to be a waste of time and money to make the excavations necessary to explore systematically the West Well deposits.

VIVET EYE TRACT 

LOCATION AND GENERAL GEOLOGIC FEATURES

The Vivet Eye tract (see pi. 1) lies in the extreme northeast corner 

of Riverside County, Calif., and occupies the eastern slope of a small 

rugged desert range known as the East Riverside Mountains. These 

mountains begin at a point 4 miles due south of Vidal and extend 

southward about 7 miles parallel with the general course of the Col-; 

orado River. Their average width is about 2 miles. At most places 

they are 2 to 3 miles from the river, but at one point midway between their north and south ends a great meander in the river's 

course carries it within a mile of their base. Riverside Peak (pi. 8, 

<4), the highest point in the range, lies opposite this meander, and 

Vivet Eye Peak, another high point, is about a mile north of Riverside Peak. At the time of Turner's visit Riverside Peak was called 

Vivet Eye; accordingly the Riverside Peak of the present report is 

the Vivet Eye Peak of Turner's report.

The mountains rise abruptly from a gently sloping plain that borders the Colorado River. (See pi. 8, B.) This plain is composed of 

alluvium in part sand and gravel washed from the mountains and
50 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

spread out in alluvial fans; in part sand, gravel, and clay deposited 

by the river. It is possible that strata of the lake-bed series underlie the alluvium along the eastern base of the mountains, because 

clay shales similar to those in the West Well tract crop out beneath 

the alluvium in several washes between Vidal and the north end of 

the range, where they form the clay-hill area here described as the 

Vidal tract.

In the vicinity of Vivet Eye and Kiverside Peaks the steep eastern face of the range consists of parallel belts of rock that trend 

north. Along the base of the foothills nearest the river are outcrops 

of granitic gneiss and granite. West of the gneiss is a belt of schist 

and quartzite, followed by a belt of massive limestone. The quartzite and limestone form most of the lower slopes of the range. 

Above the quartzite and limestone is a belt of greenish and pinkish 

quartz-sericite schist occupying the middle slopes. (See pi. 8, A, B.) 

The higher slopes and the summit of the range consist chiefly of 

massive cherty magnesi^i limestone. (See pi. 8, A.) The structural 

and stratigraphic relations of the rocks just described were not determined! The prevailing dip of the beds is about 35° W., and the 

strike is not far from north, so that the structure, considered 

broadly, appears to be simple, the belts of rock succeeding one another in orderly stratigraphic succession. However, the structure 

may actually be complex, for the beds are cut by numerous faults.

The rocks are prevailingly dark colored, the limestone and 

quartzite weathering brown and the schist weathering rusty green 

or pink. Most of the limestone is crystalline. Much of it does not 

effervesce with dilute acid and is probably dolomite. Many limestone beds contain parallel bands of chert. The schist is cut by 

veins and stringers of quartz and contains a considerable amount of 

epidote. All the rocks are more or less metamorphosed, and any 

fossils that they may originally have contained appear to have 

been obliterated. Consequently their age is unknown. The quartzite, limestone and schist series is almost certainly not younger than 

Paleozoic. Whether the granitic gneiss and granite near the river 

are unconformable beneath this series or intrusive into it was not 

determined. If unconformable, they are probably pre-Cambrian.

The schist belt lie's between 800 and 1,500 feet above sea level 

(barometric reading), or between 500 and 1,200 feet above the 

Colorado Kiver. On this belt, practically coincident with it and 

covering it like a blanket, lies a curious deposit that is conspicuous 

from a considerable distance by its light buff color, which contrasts 

sharply with the darker hues of the quartzite, limestone, and schist. 

This deposit (see pi. 8, A, B) consists largely of finely granular gypsum. (See p. 51.) The most striking feature of the deposit is its 

porous and cavernous structure. (See pi. 9, A, B.) It contains
VIVET EYE TRACT 51

numerous small cavities ranging in diameter from 1 to 6 feet, most of 

which open at the surface of the ground. Nearly everywhere the 

deposit sounds hollow under foot. The surface of the deposit is 

puffy, crusty, compact, and exceedingly rough. This compact material is difficult to penetrate with a pick, although it is porous and 

spongy, but a few inches under the surface the material is softer and 

can be worked rather easily. In texture much of the gypsite resembles granulated sugar. In most parts of the deposit, particularly 

at the surface, the gypsite contains considerable clay, which has probably been blown over the surface as dust. At many places it contains 

angular fragments of schist, which are locally so abundant that the 

material resembles breccia. The gypsite does not effervesce with 

acid and therefore probably does not contain much carbonate of 

lime. Thin lenses of powdery white salts readily soluble in water 

occur at many places in the gypsite. Most of this soluble material 

tastes alkaline or bitter rather than salty and probably consists 

largely of sulphates of sodium, potassium, and magnesium. Most 

of it gives reactions for nitrate ranging from "fair" to " very 

strong." A sample of the insoluble material tested in the chemical 

laboratory of the Geological Survey was reported to consist largely 

of calcium sulphate. Perhaps the cavities in the gypsite owe their 

existence to the lenses of loose, powdery, partly soluble material just 

described, the material breaking down and determining cavities 

because it is much more soluble than the mass of the gypsite.

The gypsite covers an area measuring about 4 miles from north 

to south and one-half to three-fourths of a mile from east to west. 

Isolated patches of the gypsite occur at intervals for a distance of 

a mile north of this area and a mile south of it. Practically all the 

gypsite overlies the schist, but at a few places it extends a short 

distance beyond the borders of the schist belt and overlies limestone 

or quartzite. Here and there within the schist belt small patches 

of schist are entirely bare of gypsite. The deposit lies upon an 

exceedingly rugged surface (see pi. 8, A,.B) and covers this surface 

without regard to topographic form or direction of slope, occurring 

on all sides of hills, on the sides and crests of spurs, oil hilltops, and 

in gulches. Likewise the bare patches of schist within the gypsite 

area are distributed without regard to the topography, occurring on 

slopes or in depressions as well as upon hilltops. The thickness of 

the deposit is variable, commonly ranging from 1 to 6 feet but averaging perhaps 3 feet for the area as a whole. Its thickness, like 

its areal distribution, appears to be unrelated to tfye topography.

A large gulch that heads between Riverside and Vivet Eye Peaks 

contains several gold mines, which were not being worked at the 

time of examination. Most of the workings are in the schist belt, 

and a great number of prospect pits and small tunnels have been
52

dug through the gypsite into the underlying schist. These excavations afford an excellent opportunity to study the gypsite, and the 

trails that connect them give easy access to large parts of the gypsite 

area that would otherwise be difficult to explore because of the rough 

topography. With the Steese camp, near one of the mines, as a 

base five days was spent exploring the gypsite deposit.

EXPLORATION

Preliminary tests were made at many different places in the gypsite 

to as great a depth as material could be readily dislodged with a 

small pick. At most of these places the gypsite itself gave no reaction for nitrate or at best only a " weak " reaction, but the loose 

powdery salts in the cavities commonly gave " good " or " strong " 

reactions. Excavations in the gypsite were then made in and around 

the cavities containing the loose salts, to determine the extent and 

average nitrate content of the niter-bearing material and also in 

situations as far as possible from niter-bearing cavities, to determine 

whether the mass of the gypsite contains significant amounts of 

nitrate.

In all 28 excavations were made 18 in and around cavities and 

10 in situations as far as possible from cavities. Most of them were 

dug in the part of the gypsite deposit that lies near the Steese mining camp, but some were dug in other parts of the deposit. All 

were deep enough to penetrate entirely through the gypsite and into 

the underlying schist. In each excavation a 5-pound sample of 

each distinct layer of material removed was taken and tested for 

nitrate. A summary of the results of this sampling follows:

Average conditions revealed by 18 excavations in and around cavities in the

Material removed

Loose, earthy, gypsiferous soil containing much clay, at surface .of 

ground. 

Porous, spongy, compact gypsite, in places containing fragments of 

schist. 

Lenticular layers of whitish soluble salts mixed with powdery gypsum 

and in places containing fragments of schist. The layers are usually 

more than 3 feet and less than 12 feet in horizontal extent.

Transition from gypsite to bedrock; cracked and weathered schist fragments cemented by gypsum and cut by veins of gypsum. Here and 

 there the deposit contains a small amount of soluble salts. 

Weathered bedrock: quartz-sericite schist traversed by veins of gypsum.

Range in 

thickness 

(inches)

1-2 

12-36 

4-18

12-24

Character of field tests

"Negative." 

"Negative" to"weak."

"Fair" to "very 

strong"; for the most 

part "good" to '' strong." 

"Weak "to "fair."

"Negative."

To check the field tests and to determine more accurately the nitrate content of the better material five selected samples were sent to 

the chemical laboratory of the Geological Survey for determination. 

Each sample was taken from a different excavation, and each represented the best material, as indicated by the field tests, encountered
VIVET EYE TRACT 53

in the excavation namely, the loose, powdery white material occurring in cavities in the gypsite. The 5 excavations were selected 

at random from 12 dug at different places in the gypsite deposit 

within a radius of a mile from the Steese camp. The average nitrate 

content of these five samples as determined in the laboratory may 

be considered an indication of the percentage of nitrate that the 

material in the cavities contains, although the estimate is subject to 

considerable error owing to the small number of samples taken. The 

determinations follow:

Nitrate determinations of samples of loose powdery salts from five excavations

No.

1

?,

3 

4

fi

Location of excavation (all altitudes barometric)

of Kiverside Peak, at 1,150 feet. 

200 feet southwest of No. 1, at 1,200 feet.. ____ .

About H mile southwest of Steese camp, on south 

bank of ravine, at 1,000 feet. 

About Vi mile west of Steese camp, on trail leading west, at 900 feet.

Thickness of 

material 

(inches)

6

12

12 

6 

8

Depth 

below 

surface 

(inches)

24

24

12 

16 

12

Rating of field 

test

"Fair"........-

--...do- . 

"Very strong".. 

.....do.. .... .

Percentage of nitrate as 

NaNOsas 

determined 

in laboratory

0.96

5.00

5.22 

11.65 

12.70

Average percentage of NaNOj in 5 samples, 7.1.

The material represented by samples 2 and 3 contains fragments 

of schist and rests on quartz-sericite schist. Plate 9, A, B, shows 

the cavity in which sample 4 was taken and gives a good idea of 

the character of the ground in which the excavations in and around

cavities were made.

o

Average conditions revealed by 10 excavations in the gypsite in situations 

as far as possible from niter-bearing cavities

Material removed

Loose; earthy, gypsiferous soil containing much clay; 

at surface of ground. 

Porous, spongy, compact gypsite, in places containing 

fragments of schist.

Transition from gypsite to bedrock; schist fragments 

& cemented by gypsum. 

Weathered bedrock; quartz-sericite schist containing 

veins and stringers of gypsum, some of which, as exposed in prospect holes and tunnels, extend downward at least 4 feet into the schist.

Range in 

thickness 

(inches)

1-2 

12-36

12-24 

(?)

Character of field tests

"Negative."

"Negative" on level or gently sloping 

ground; "negative" to "weak" on 

steep slopes or in protected situations. 

"Negative" to "weak."

"Negative."

These field tests indicate that the mass of the gypsite contains only 

insignificant amounts of nitrate and that the schist underlying the 

gypsite contains no nitrate. To check the field tests, five selected 

samples were sent to the chemical laboratory for determination.
54 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

These samples were taken from three different excavations selected 

at random from 10 dug at different places in the gypsite deposit 

within a radius of a mile from the Steese camp. Three of these 

samples represent material on gentle slopes and two material on 

steep slopes. The determinations follow:

Nitrate determinations of samples of gypsite from three excavations

No.

1

?,

3

4

fi

Location of excavation

About 1 mile southwest of 

Steese camp, on gentle 

slope just south of summit 

of. a divide between two 

gulches, at 1,100 feet. 

Same as No. 1 ____ .

About H mile southwest of

Steese camp, on steep slope 

at 900 feet. 

Same as No. 3 ______ ...

100 feet west of No. 3, on

gentle slope.

Material represented 

by sample

Loose, earthy gypsiferous soil overlying gypsite.

site. 

 .do... 

site to bedrock; 

weathered schist 

fragments cemented by gypsum. 

 do....... .... . ...

Thickness of 

material 

(inches)

2 

20

18

24

12

Depth 

below 

surface 

of 

ground 

(inches)

0-2 

2-22

2-20

20-44

12-24

Rating of 

field test of 

sample

"Negative".. 

 do.... 

"Weak".....

.....do.. ...

"Negative"..

Percentage 

of NaNOs 

in sample 

as determined in 

laboratory

None. 

Do.

Trace.

Do.

None.

These determinations confirm the results of the field tests and 

strengthen the conclusion that the mass of the gypsite is practically 

barren of nitrate.

CONCLUSIONS

The nitrate of the Vivet Eye tract is associated with deposits of 

loose, powxiery saline material occurring in small cavities in gypsite. 

The gypsite itself is practically barren of nitrate, containing only, 

traces here and there. The deposits of loose saline material are 

small for the most part less than 18 inches thick and less than 12 

feet in horizontal extent and are distributed irregularly through 

the gypsite. They consist chiefly of sulphates of calcium, sodium, 

potassium, and magnesium, but all of them contain some nitrate, and 

many contain a considerable percentage of nitrate. Chemical determinations of five representative samples show amounts of sodium 

nitrate ranging from 0.96 to 12.70 per cent of the total sample and 

averaging a little over 7 per cent. From these determinations and 

from numerous field tests in different parts of the tract it would seem 

that the sodium nitrate content of the niter-bearing material should 

average at least as high as 5 per cent and may average higher than 

5 per cent. Although the pockets of niter-bearing material are 

fairly numerous they constitute a very small part of the total quantity of gypsite. If all the loose material that could be gathered 

from the cavities were taken out and treated it could probably yield
VIDAL TRACT 55

only a few tons of sodium nitrate. More niter-bearing material 

could be obtained by excavating around the cavities, but the amount 

of nitrate that could be produced from the total quantity of material 

available would still be measurable in tens of tons, and the cost of 

removing the mass of compact gypsite to get at the material would 

be prohibitive. The deposits therefore can not be considered commercially valuable.

BEAL TRACT

Brief reconnaissance was made of the Beal or Topock tract of 

Turner, which lies along the west side of the Colorado River 6 to 8 

miles southeast of Needles (see pi. 1) and extends a mile or more west 

of the river. The automobile highway from Needles to the Topock 

bridge and the Atchison, Topeka & Santa Fe Railway track pass 

through a part of it. The conditions in this tract are essentially 

the same as those in the West Well tract, described above. The 

clay beds with which the niter-bearing ground is associated crop 

out only along the sides of washes cut through the overlying 

alluvium. At most places they form bluffs or are carved into steep 

badland slopes that are unfavorable for the accumulation of large 

or continuous areas of caliche, but in a few places where the gravel 

cover has been eroded away they form gentle slopes and rounded 

clay hills. No single area of clay beds exposed in the tract is as 

large as the 400-acre area of the West Well tract, and the total area 

of clay beds is much smaller than in the West Well tract. The 

nitrate, as in the West Well tract, is concentrated in a thin saline 

layer of broken clay, in places cemented and calichelike, at the base 

of the surface soil. A number of tests were made in the niterbearing ground at different places, but no material giving a reaction 

that would indicate the presence of as much as 3 per cent of sodium 

nitrate was found. It was obvious that if the West Well tract 

offered no hope of commercial exploitation the smaller Beal tract 

likewise offered none.

VIDAL TRACT

The Vidal tract is a clay-hill area like the West Well and Beal 

tracts and is one of many similar areas that occupy parts of the 

valley of the Colorado River above and below Needles. It is about 

o miles northwest of the Vivet Eye tract. (See pi. 1.) Attention 

had been called to the area by j. M. Wilson, of Vidal, who had been 

mining clay in it and shipping the clay to a plaster mill at Amboy, 

Calif. Mr. Wilson said that a number of samples taken from the 

clay outcrops had been analyzed and found to contain nitrate and 

that the clay was believed to be impregnated with nitrate. Accordingly, in company with Mr. Wilson the writer spent the greater 

part of a day there.testing the ground for nitrate and taking a few
56 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

samples for analysis. The area proved to be a tract of at least 200 

acres of fairly continuous clay outcrops, in part forming barren clay 

hills. It lies in a large wash 2!/2 miles southwest of Vidal that drains 

eastward past the north end of the East Riverside Mountains to the 

Colorado River. As in all the other clay-hill nitrate tracts near 

the river, the clay beds are mantled by alluvium. The clays are 

paler in color and freer from sandy beds, but they do not otherwise 

differ in any important respect from those in the 400-acre area of 

the West Well tract. At many places a compact caliche a few inches 

to a foot thick was found on the clay beds. This caliche gave reactions for nitrate ranging from weak to good but evidently 

consists chiefly of sodium chloride. Recently made excavations dug 

in mining the plaster clay afforded a good opportunity to test the 

bedrock clay for nitrate at depths as great as 7 feet. At no place, 

however, was a reaction for nitrate obtained from the clay. In order 

to check field tests three samples of caliche and two' samples of the 

bedrock clay were saved and sent to the chemical laboratory for 

determination of the nitrate content. The results of this sampling 

follow:

Tests of 2-pound nitrate samples from Vidal tract

No.

1

2

3

4

5

Locality

2H miles south of

Vidal, in small

clay hill from

which plaster

clay had been 

mined by Mr.

Wilson.

50 feet east of No.

1, in same hill.

Fresh cut 6 feet

deep from which

plaster clay had

been mined.

Near base of small

hill 100 yards

south of No. 1.

100 feet south of

 -No. 3 shaft in

bed of wash.

M mile northwest

of No. 1.

Material

Caliche-..

Bedrock...

Caliche.-.

Bedrock . _

Caliche. .-

if

43 ® *^ o

§*<2

p

14-20

60-72

7-13

48-GO

C-12

Character of 

field test

Good.- .

Negative.- _

Fair. ........

Negative.. ...

Weak... ..

o> 

*0

M *Z C?

-*-» 03 P

~fc8

1.09

None.

0.86

None.

Trace.

Remarks

At the surface is a 2-inch layer of

compact clay soil, barren of

vegetation . B eneath this layer

is a 12-inch layer of powdery

salts mixed with clay, followed 

by the caliche, which is hard

and compact and tastes strongly of sodium chloride. Beneath the caliche is nearly horizontal yellowish clay shale, the

"plaster clay."

Clay shale ("plaster clay") underlying the caliche represented by No. 1.

.

At the surface the usual layer of

knobby, compact clay soil 1

inch thick, underlain by 6

inches of powdery saline material mixed with clay, followed

by 6 inches of compact salty

caliche like No. 1 and horizontal beds of bull shale which

give no reaction for nitrate.

All material in excavation

moist.

Bluish-gray clay shale in nearly

horizontal beds at bottom of a

5-foot shaft.

Caliche of the loose, flaky type.

overlying nearly horizontal

beds of bluish-gray clay shale

that give no reaction for nitrate.
DANBY LAKE 57

These analyses indicate that the caliche in the Vidal tract is no 

richer in nitrate than that in the West Well tract and that the 

bedrock clay is practically barren of nitrate.

DANBY LAKE

REASON FOB EXAMINATION

Bailey 54 states:

The existence of niter has been reported as discovered in the playa deposits 

near the salt beds at Danby Lake, and locations were filed upon the land in 

1901; but no development work has been done, and no analyses are at hand at 

the date of this bulletin.

LOCATION AND GENERAL GEOLOGIC FEATURES

Danby Lake lies in the eastern part of the Mohave Desert, in the 

extreme southeastern part of San Bernardino County, Calif. (See 

pi. 1.) The Parker cut-off of the Atchison, Topeka & Santa Fe 

Kailway, which leaves the main line at Cadiz, Calif., and runs to 

Phoenix, Ariz., skirts the northeast shore of the lake about 25 miles 

southeast of Cadiz. Two stations on the railroad are near the 

lake. One, Milligan, is on a detrital slope about a mile north of the 

northwest end of the lake; the other, Salt Marsh, is only a few hundred feet from the lake, near the southeast end. A road that 

branches from the National Old Trails highway near Cadiz and 

leads to Parker and Phoenix crosses a part of the lake between Milligan and Salt Marsh. This road also is popularly known as the 

Parker cut-off.55

Danby Lake occupies the lowest part of an irregular inclosed basin 

which may be called the Danby Basin. The altitude of the lake 

is probably not far from 600 feet, for that of Salt Marsh, the station 

nearest the lake shore, is 626 feet. The Danby Basin is separated 

from the Bristol Basin, to the northwest, by a divide of low rocky 

hills. The Bristol Basin contains Cadiz and Bristol Lakes, two 

large playas very similar to Danby Lake. The lowest part of the 

divide is at least 500 feet (barometric reading) higher than the 

surface of Danby Lake. Although a few alluvial gaps extend 

through the hills in the divide the alluvium in them is evidently thin, 

because bedrock is exposed in the bottom of gullies cut in the gaps; 

the divide is therefore a rock divide. The Danby Basin is separated 

from the Blythe Junction Basin, to the southeast, by a low alluvial 

divide west of Rice (formerly Blythe Junction). The only large 

arm of the Danby Basin is a long, open detrital valley that extends 

far to the north, between the Old Woman Mountains and the Turtle

« Bailey, Gilbert, op. cit., p. 180.

M For log of road see Thompson, D. G., op. cit., pp. 222, 223,
58 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

Mountains. This valley, which drains directly into the lake between 

Milligan and Salt Marsh, is at least 40 miles long and averages 

perhaps 15 miles in width. Elsewhere the basin is bordered by 

ranges of mountains that lie near the lake. North of the lake are the 

Old Woman Mountains; south and west of the lake, the Iron 

Mountains. The lakeward face of the Iron Mountains is steep and 

probably represents a dissected fault scarp. As nearly as could be 

determined, most of the rocks in the ranges inclosing the basin are 

pre-Tertiary, chiefly granite. The rocks in the Old Woman Mountains are nearly all granites. Those in the low hills of the divide 

northwest of Danby Lake and those in the Iron Mountains are 

granites, gneisses, and partly metamorphosed sediments. Tertiary 

volcanic rocks, however, appear to form a considerable part of the 

Turtle Mountains.

Danby Lake is about 14 miles long and 1 to 4 miles wide. The 

narrowest part of the lake is near the northwest end. Most of the 

surface of the lake consists of a hard, salty clay crust which breaks 

through when walked upon, and which has a curious rough, puffy 

appearance suggesting a muddy field that has been trampled 

by cattle. (See pi. 10, A.) This salty crust is about a quarter of 

an inch thick. Beneath it is a layer of dry powdery clay mixed 

with tiny transparent salty crystals, some of which have a bitter 

taste. This dry layer, which at most places is several inches thick, 

grades downward into moist salty clay containing small crystals of 

gypsum. At the southeast end of the lake much of the surface consists of unconsolidated deposits composed of beds of loose gypsum 

crystals mixed with varying amounts of clay. At places these 

gypsiferous beds are eroded into curious small mesalike forms. 

Ground in the neighboring Cadiz Lake is reported to contain deposits 

of celestite as well as gypsum and salt. Gypsum deposits in Bristol 

Lake have been worked for many years.

In the southeastern part of Danby Lake the surface deposits of 

saline clay are underlain by a body of rock salt which at some places 

is exposed practically at the surface. Numerous pits and quarries, 

some of them as much as 8 feet deep, have been dug in the .salt body 

in this part of the lake, but none of them were being worked when 

visited. Some of these excavations afford good cross sections of a 

part of the salt body. They show that it consists of solid beds of 

rock salt a foot or more thick alternating with thin beds of clay. 

Mr. Bedell, the station master at Salt Marsh, stated thajt the salt 

body is said to reach a thickness of at least 10 feet in this part of the 

lake. He had no information as to what lies beneath that depth.

In the northwestern part of the lake the surface deposits are 

also underlain by a body of rock salt. A shaft (No. 1) dug by Mr. 

Mclntosh, the section foreman at Milligan, at a point in the middle
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 10

A. SHAFT NO. 2, PAJNBY LAKK, 2 MILKS SOUTHWKST OF MI1JJGAJN 

Shaft is 9 feel. deep.

li. DIULLI.NG \\ITH SOIL AUGER AT LOCALITY SHOWM IN A
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 11

A. RVILIFF CLAIMS SlH)TH\\ KST (>K SliO.SHO.NL

View looking east from locality Xa on Figure 3. b, Lake beds; c, Tertiary rocks; d, Paleozoic 

rocks; X, borax mine; al, alluvium. Arrow indicates nitrate test pit.

B, RATLIFF CLAIMS NORTH OF SIIOSHONK

Arrows indicate nitrate test pits dug through alluvium into lake beds that are practically

concealed.

C. WHITE BED TESTED FOR NITRATE NEAR LOCALITY Xs ON FIGURE 4 

/ al. Alluvium. ; . -
DAETBY LAKE 59

of the lake about 2 miles south of Milligan, reaches the salt body 

at a depth of 6 feet. A hole drilled in the bottom of the shaft 

penetrates the salt to a depth of ,a foot. This hole is filled with 

brine from the salt body. The shaft is 4 by 5 feet and is cased, so 

that the deposits penetrated are not exposed, but the log of the shaft 

contributed by Mr. Mclntosh shows that the salt body is here overlain 

by 6 feet of alternating layers of sandy and salty clay and gypsiferous sand. This shaft is 2^4 miles east of the ruins of the "salt 

house " a house built of blocks of rock salt many years ago on the 

lake near its northwest end. Another shaft (No. 2; see pi. 10, A) 

dug in the lake by Mr. Mclntosh at a point half a mile northwest 

of the shaft just described is 4 by 5 feet and 9 feet deep. A hole 

drilled in the bottom of the shaft reaches the salt body, 2 feet deeper. 

Brine now fills the shaft up to a level 6 feet beneath the surface of 

the ground. The shaft is cased and tightly covered, so with Mr. 

Mclntosh's aid a hole was drilled near by with a soil auger. (See 

pi. 10, B.) The first 3 feet below the surface was sand;.next came 

3 feet of moist plastic brown clay; then 5 feet of wet dark-blue clay 

containing numerous small crystals of gypsum, which increased in 

abundance with depth; and finally, at 11 feet beneath the surface, 

solid rock salt was struck. Immediately brine gushed into the hole 

and rose 4 feet above the surface of the salt. Northwest of the two 

localities just described, in the extreme northwestern part of the 

lake, the salt body is said to lie nearer the surface. That part of the 

lake was not visited. Along the north shore of the lake, about a 

mile from the salt house, were noted loose deposits of granular 

gypsum and clay similar to those at the southeast end of the lake. 

The part of the lake midway between the northwest and southeast 

ends is built up higher than the two ends by recent playa wash, 

much of which is dissected by small gullies. Apparently most of 

this recent wash material is derived from the long valley already 

described that drains into the lake from the north between Milligan 

and Salt Marsh. As there are no excavations in this part of the 

lake, drilling would be necessary to determine whether the salt body 

underlies it. However, the fact that the salt underlies both ends of 

the lake suggests that it may be continuous under this middle portion.

EXPLORATION

The surface deposits of Danby Lake were tested for nitrate at 

five places in the northwestern part of the lake and at five places 

in the southeastern part by digging pits to a depth of 2 feet and testing in each pit the surface crust, the powdery clay layer beneath it, 

and the moist clay beneath the powdery clay. No reactions for 

nitrate were obtained. 

3201 31 5
60 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

The beds of rock salt and clay in all the excavations described 

were also tested, and near Mr. Mclntosh's shaft No. 2 (see pi. 10, 

A, B) each layer of material removed was tested in drilling with 

the soil auger down to and including the surface of the salt body, 11 

feet below the surface of the ground. The brine in each excavation 

and the salt crystals that formed a crust upon the brine were tested. 

No reaction for nitrate was obtained.

A number of samples of brine and of different types of surface 

deposits of the lake were sent to the chemical laboratory for partial 

analysis to check the results of field tests. None of them when 

analyzed contained nitrate. The details of this sampling follow:

Sample 01, brine from the bottom of an open shaft 2 miles south 

of Salt Marsh and about 3 miles northwest of the southwest end of 

the lake. This shaft was the deepest excavation then remaining 

open in that part of Danby Lake. It penetrated 7 feet into solid 

beds of rock salt alternating with thin layers of clay, and the brine 

stood 1 foot in the bottom and was covered with a crust of salt 

crystals (sample 1) which had to be broken to procure the brine 

sample. According to Mr. Bedell, brine enters the hole only after 

a heavy rain. A desert thunderstorm had occurred about a month 

before the sample was taken. The specific gravity of the brine was 

1.203 at a temperature of 23° C. The percentage of total salts was 

26.79 to 26.84 (two determinations). The percentage of potash 

(K2 0) in the total salts was 0.2. No nitrate in the form of sodium 

nitrate (NaNO3 ) was present.

Sample 02, water from the Atchison, Topeka & Santa Fe Railway 

well at Salt Marsh, only a few hundred feet from the lake. The 

well is 600 feet deep, but the water was being pumped from a depth 

of 300 feet. It is soft, has a peculiar taste, and is not used for 

domestic purposes. The well is sunk at a point where the detrital 

wash entering Danby Lake from the north merges with the playa 

beds of the lake. The sample was taken to show whether potash or 

nitrate occurs in ground water that enters the lake depression. The 

specific gravity of the water at 23° C. was 0.997. The percentage 

of total salts was 0.047, and the potash content of the total salts 

was 2.02 per cent. No nitrate in the form of NaN03 was present.

Sample 03, brine from shaft No. 1, described above, obtained by 

breaking through the salty crust. The shaft was cased and tightly 

covered. Mr. Mclntosh states that the level of the brine in this 

hole is entirely independent of rains and that before the rain of the 

preceding month the brine had stood for two years during which 

practically no rain fell. The specific gravity of the brine at 23° C. 

was 1.220. The percentage of total soluble salts was 27.95 to 28.02 

(two determinations). The potash content of the total soluble salts 

was 0.23 per cent, but no nitrate in the form of NaNO3 was present.
DANBY LAKE 61

The composition of the salts was essentially Nad, Na2S04 j and a 

little KC1.

Sample 04, brine from shaft No. 2, described above. The level 

of the brine is said to be independent of rains. According to Mr. 

Mclntosh this brine has been analyzed at different times with contradictory results: one analysis showed as much as 3 per cent of K2 0; 

another showed only a trace. The bottle containing the sample 

sent to the Geological Survey was broken in transit so that it was 

impossible to check the analyses cited.

Sample 1, crust of salt crystals noted under sample 01. No nitrate 

was found.

Sample 2, porous, salty, calichelike layer about 1 foot thick taken 

from the surface of Danby Lake about 100 yards north of the shaft 

which furnished samples 01 and 1. This layer overlies beds of 

rock salt and clay and underlies curious loose, crusty deposits consisting of gypsum crystals mixed with clay, which range in thickness from 1 to 3 feet and are eroded into little mesalike forms. In 

the laboratory no nitrate was found in this material.

Sample 3, moist, saline clay about 1 foot below the surface of the 

ground at a point about 4 miles west of Salt Marsh. The surface 

here has a dirty whitish salty crust, which has a puffy appearance 

and looks everywhere as if cattle had trampled it. Under this 

crust is about 3 inches of dry, powdery clay full of transparent 

soluble crystals that have a bitter taste. Beneath lies the moist 

salty clay represented by the sample. These conditions are typical 

of the greater part of the surface of Danby Lake except where the 

salt body is very near the surface. In the laboratory this sample 

yielded no nitrate.

Sample 4, powdery clay, 4-inch layer, mixed with small transparent 

crystals just under the surface crust at the border of Dauby Lake 

about 1 mile south of Milligan. In the laboratory no nitrate was 

obtained from this sample.

CONCLUSIONS

The absence of nitrate in the salt body that underlies Danby Lake 

is consistent with its absence in the much larger salt body that underlies Searles Lake,58 in the salt deposit on the floor of Death Valley 

(see pi. 18j A), and in beds of rock salt in Tertiary strata. The bed 

of rock salt in the Tertiary strata of the Saratoga nitrate field, which 

was prospected and tested in great detail for nitrate, contained 

none," and even the caliche over the salt bed was entirely barren. 

This Tertiary salt bed in the Saratoga Hills is identical in character 

and origin with the Quaternary salt bed at Danby Lake, differing

68 Gale, H. S., op. cit., p. 297. B7 Noble, L. F., and others, op. cit., pp. 48, 49.
62 NITRATE DEPOSITS IN SOUTHEASTERN- CALIFORNIA

from it only in age and position. It has been upturned and eroded 

since it was deposited, whereas the salt deposit in Danby Lake lies 

in its original position. Similar gypsiferous clays are associated 

with the salt at both places. Tests in another Tertiary salt bed in 

the valley of the Virgin River, Nev., yielded no reaction for nitrate. 

(Seep. 86.)

Tests of the clay deposits of the surface of Danby Lake were not 

sufficiently numerous to demonstrate that the deposits are everywhere barren of nitrate; possibly at places they contain a trace; but 

the results certainly warrant the statement that the deposits are 

practically barren.

RATLIFF NITRATE CLAIMS AND OTHER DEPOSITS 

NEAR SHOSHONE

LOCATION

The Racliff claims include 2,280 acres of ground lying on the west 

side of the valley of the Amargosa River near Shoshone, Calif. (See 

pi. 1 and figs. 3 and 4.)

A report on the property made by an engineer and submitted to 

Mr. Ratliff in May, 1918, contains the following statement:

I believe it probable that a thorough examination will show this property 

very valuable for niter and possibly for two or three other salines. I made 

numerous field tests and a considerable number of analyses and in many cases 

found niter in paying quantities. I consider the prospects more than ample 

to justify a thorough and complete examination and a report on this property.

A list of over 100 analyses of samples from the property accompanies the report. These analyses show amounts of sodium nitrate 

ranging all the way from " traces " to over 20 per cent and averaging probably over 5 per cent for the samples as a whole.

The fact that the Geological Survey had just examined large 

parts of the Zabriskie field 5S (the nitrate field in which the Ratliff 

claims lie) and had found the conditions there entirely unfavorable 

to the existence of nitrate in commercial quantity established a 

strong presumption against the existence of valuable deposits in 

the Ratliff ground. Nevertheless, the analyses submitted to Mr. 

Ratliff by the engineer were so high that, in view of the emergency 

created by the war, no possibility, however remote, of the existence 

of valuable deposits could be overlooked. Accordingly in October. 

1918, the writer, with John Waltenberg as assistant, spent 10 days 

prospecting and testing the ground.

M Noble, L. F., and others, op. cit., pp. 61-67.
R. 6 E R.7

19

irffoll

, w.. 

test 

^Bul

pag

FIGURE 3. Sketch map of claims of Messrs. Ratliff and others 
NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

o

R.7 E.

EXPLANATION

 :-/;'---:---.-:>P^

 %. . '. .> :' . ** ^f-'- ' A-^': -.-:/: -^m

X X? Localities where rock 

. was tested for nitrate

General Land Office 

survey corner found

Claim boundary 

M,,Mj,,M3 Monuments found

i Milt 

FIGDRE 4. Sketch map of claims of Messrs. Ratliff and others north of Shoshone, Calif.

GENERAL GEOLOGY

The Zabriskie nitrate field lies in the valley of the Amargosa 

Eiver about Shoshone and Tecopa. The geology of-this part of the 

valley has been described briefly in earlier reports.59

General geologic section of ZabrisTcie nitrate field, Amargosa Valley, CaUf.

Recent alluvium: Valley fill and alluvial-fan wash; unconsolidated 

sand, gravel, and clay.

Unconformity.

Lake beds: Stratified sand, gravel, clay, and volcanic ash; very 

loosely consolidated; deeply dissected; nearly horizontal; age 

probably Quaternary; the nitrate deposits of the Zabriskie field 

are associated with these lake beds; near Shoshone the lake 

beds contain deposits.of bentonite.

Unconformity.

Tertiary rocks: Volcanic and sedimentary rocks of very diverse 

character tuff, breccia, lava, ash, clay shale, sandstone, and conglomerate; moderately consolidated; tilted, folded, and faulted; 

comprising at least two unconformable series of rocks, the older 

of which is probably Miocene, the younger probably Pliocene; the 

Miocene (?) beds contain a deposit of colemanite near Shoshone 

and deposits of gypsum near Acme; the nitrate deposits of the 

Upper and Lower Canyon fields are associated with the Miocene (?) beds.

59 Campbell, M. R., Reconnaissance of the borax deposits of Death Valley and Mohave 

Desert: U. S. Geol. Survey Bull. 200, pp. 14, 15, 1902. Noble, L. F., and others, op. clt, 

pp. 59-88. Noble, L. F., Note on- a colemanite deposit near Shoshone, Calif., with a sketch 

of the geology of a part of Amargosa Valley: U. S. Geol. Survey Bull. 785, pp. 63-73, 1926.
RATLIFF NITRATE CLAIMS 65

Unconformity.

Pre-Tertiary rocks: Limestone, quartzite, slate, schist, granite, and 

gneiss; highly indurated; tilted and faulted; at some places 

contain deposits of metallic minerals and deposits of talc; sedimentary rocks partly metamorphosed; age of sedimentary rocks 

in part Cambrian; age of other rocks unknown.

The distribution of the pre-Tertiary and Tertiary rocks, the lake 

beds, and the recent alluvium on the Katliff claims is shown in 

Figures 3 and 4.

Only the lake beds need be considered in the present report, as 

the clay-hill nitrate of the Zabriskie field is associated only with 

(hem. Their outcrops constitute the Zabriskie field.

LAKE BEDS

At some time after the end of the Tertiary period the waters of 

the Amargosa Kiver were ponded, and a lake was formed in which 

beds of clay, sand, and gravel were deposited. These deposits cover 

most of the floor of the valley between Tecopa and a point several 

miles north of Shoshone and extend several hundred feet up the 

slopes on the sides of the valley. (See pi. 11, A.) The lowest exposures of the beds lie at an altitude of about 1,300 feet along the 

Amargosa River near Tecopa. The upper limit of the beds at most 

places around the sides of the valley is between 1,700 and 1,800 feet, 

but in some of the larger embayments formed by tributary valleys 

it appears to be higher. To the eye the beds appear horizontal; 

actually, however, they dip very gently toward the center of the 

valley from all sides. Their total thickness probably does not exceed 

400 feet. The beds cover an area of at least 100 square miles.

The barrier behind which the waters were ponded to form the 

lake lies south of Tecopa and is composed partly of Pliocene (?) 

fanglomerates and partly of older rocks. After the basin of the 

lake was filled with sediments, possibly to the level of its outlet, the 

Amargosa River began to cut down through the barrier and to 

lower its bed. Since that time it has carved for itself below Tecopa 

a deep rocky canyon which is one of the striking scenic features 

of the region. As the river bed was progressively deepened the 

lake deposits were subjected to erosion. As a result they have been 

dissected almost to their base, so that over most of the area in which 

they are exposed they now form mesas and badlands.

The only exposures of older rocks within the lake-bed area are 

some low hills. One of these hills stands half a mile northeast of 

Shoshone, in the middle of the valley; it is composed of black 

basaltic lava, tilted eastward and probably of Tertiary age. Other
66 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

hills that form a small group north of Tecopa are composed of preTertiary rocks. A strong bench, or terrace, which encircles the 

highest hill near its summit and bevels the steeply dipping beds of 

quartzite of which the hill is composed, probably represents an 

ancient shore line of the lake. These hills once formed islands in 

the lake; later they were partly or wholly buried by sediments; 

and now they are exhumed by the erosion to which the lake beds 

have been subjected.

Below an altitude of about 1,600 feet in the lake-bed area nearly 

all the sediments are true lake beds, consisting of white, buff, yellowish, and greenish fine-textured saline clay. At many places the soil 

upon their outcrops contains a large amount of soluble salts, chiefly 

sulphate and chlorides of sodium, showing that the beds contain 

considerable saline material.

Above the 1,600-foot level the beds become predominantly sandy, 

contain lenses of gravel, and gradually pass upward into beds that 

are practically all fanglomerate and differ little from recent alluvial-fan wash. Compared with the beds below the 1,600-foot level 

they contain little soluble saline material. The uppermost sediments apparently represent detrital material washed into the basin 

from the surrounding hills, near or perhaps soon after the end of 

the period when the lake existed. Indeed, it seems highly improbable from their character that they are lake beds at all, but they are 

grouped with the lake beds for convenience of description. Except 

in a small part of sec. 36, T. 22 N., R. 6 E. (unsurveyed), south of 

Shoshone, all the beds on the Ratliff claims are above the 1,600-foot 

level. (See figs. 3 and 4.)

At about the 1,600-foot level, in the vicinity of Shoshone, a bed 

of white volcanic ash (see pi. 12, B) is interstratified with the sand and 

clay. Just west and north of Shoshone, in the vicinity of the 

Shoshone hot spring, this volcanic ash has been altered to material 

known locally as " soap," " fuller's earth," or " bentonite," which is 

mined at several places. The largest deposit is worked by the Associated Oil Co. These bentonite deposits were discovered by Mr. Fairbanks, of Shoshone. An interesting account of them has been 

written by John Melhase, geologist, of the Southern Pacific Co.,60 

who has proposed for the bentonites occurring along the Amargosa 

River the name " amargosite " as a means of distinguishing this 

particular material from bentonites occurring elsewhere. Melhase 

writes:

60 Melhase, John, Mining bentonite in California: Eng. and Min. Jour. Press, vol. 121, 

pp. 837-842, May 22, 1926.
RATLIFF NITRATE CLAIMS 67

The bentonite deposits are nearly always found in areas where beds of incrustations of alkaline salts abound. Especially is this true of the Amargosa deposits, where the surrounding lowlands are covered with mixtures of sodium 

sulphate, sodium carbonate, common salt, borax, and gypsum. Efflorescences 

and sometimes thick crusts of these salts also cover and obscure the bentonite 

beds as well. This leads to the belief that, waters charged with these salts 

are responsible for the alteration of the ash beds from which the Amargosa 

bentonite is clearly derived. This belief is further strengthened by the fact 

that the bentonite beds are always localized in the vicinity of extinct or living 

thermal springs the waters of which carry more or less of the alkaline salts 

in solution. The volcanic ash beds interstratifled in the sedimentary deposits 

were porous enough to permit ready percolation of the alkaline waters for a 

considerable distance from their source, and the extent of percolation may be 

said to determine the area over which the ash beds were altered to bentonite.

According to Melhase,61 a deposit of bentonite occurs in the Tertiary beds of the Upper Canyon nitrate field, as well as in the 

Quaternary lake beds already described. This Tertiary deposit lies 

4 miles southeast of Tecopa, in a canyon draining into the Amargosa 

River.

RECENT ALLUVIUM

Part of the recent alluvium in the Amargosa Valley consists of 

alluvial-fan deposits gravel, sand, and boulders swept down by 

streams over the lower slopes of the valley. In the higher parts of 

the lake-bed area these deposits cap the mesas into which the lake 

beds are carved; lower in the area they fill the beds of the innumerable washes that separate the mesas. (See pi. 11, A.) The rest of 

the alluvium is valley fill clay and sand deposited by the Amargosa 

River. Most of it is clay, which forms marshy flats along the river.

GENERAL CONSIDERATIONS

Erosion and dissection of the lake beds has been going on ever 

since the barrier that formed the lake was cut away, and great aprons 

of alluvial waste from the bordering hills have crept down since that 

time, so that now the lake-bed area is a succession of flat-topped, 

gently sloping, gravel-capped mesas alternating with steep-sided, 

alluvium-filled washes. (See pi. 11, A.) Consequently, the lake 

beds crop out mostly in bluffs along the alluvium-filled washes. 

Their exposures on the Ratliff claims, then, amount to but a small 

fraction of their areal distribution shown on Figures 3 and 4. A 

still smaller fraction of the exposures consists of slopes gentle enough 

to be covered with soil and thus to form the type of ground which 

experience has shown to be favorable for the accumulation of caliche.

01 Melhase, John, op. clt., p. 838*
68 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

By far the greater part of the ground consists of gravel-covered surfaces bordered by steep bluffs of lake beds. As a caliche nitrate field 

the ground is, therefore, from its very nature, hopeless. Even if 

patches of caliche rich in nitrate could be found, their area would be 

so limited by these natural factors that the caliche would be of no 

commercial value.

EXPLORATION

Ten days were spent traversing many well-exposed sections of the 

lake beds from top to bottom in all parts of the Katliff claims. More 

than 265 field tests for nitrate were made in such a way as to cover 

some part of the outcrop of every bed in each section. No nitratebearing caliche was found anywhere on the claims. Wherever soil 

is present on the beds it appears to grade down into them without 

the intervention of any hard saline layer. At most places this soil 

is deep, loose, and very powdery, and at some places it is mixed with 

white powdery salts chiefly sulphates of sodium and calcium. Here 

and there " fair " to " good " reactions for nitrate were obtained in 

the soil at a depth of about a foot.. Below this depth the reactions 

were negative or very weak. In brief, the nitrate-bearing material 

on the claims is essentially a layer of soil that does not average over 

a foot in thickness and appears to be confined chiefly to outcrops of 

sandy clay beds. .It is spotty in distribution even on the same bed. 

As may be seen from the results that follow, the nitrate content of 

this material must average only a small fraction of 1 per cent.

When it became evident that no nitrate caliche exists on the claims^ 

the possibility was considered that concentrations of nitrate might 

exist in the bedrock strata that is, in the lake beds themselves. The 

engineer who examined the claims had reported to Mr. Ratliff that 

he had found that "some of the rich nitrate ground on the claimsgoes down to depths of 10 feet underground." Pits and trenches 

were therefore dug in all the ground that was specifically designated 

by the engineer as the richest. Nowhere was more than the smallest 

trace of nitrate found in the bedrock itself. Supplementary tests 

of the bedrock by traverses all over the claims yielded similar results.
EATLIFP NITRATE CLAIMS 69

Results of tests for nitrate in pits and, trendies dug on Ratliff claims

Areas north of Shoshone

[See fig. 4 and pi. 11, B]

Locality 

as marked 

on sketch 

maps

Xi.. ......

x>..... ...

Xs. ~ -

Character of underlying rock 

 do.-. 

 do...... .. 

 do-':. 

White sandstone..

 do.. 

....do-.- 

f.... do.. ...... ... .

 do....... .....

 ,do... ...

 do-.. 

... .do... ... ...

 do.. 

 do.- 

Character 

of excavation

Pit

... do.. .

...do.. 

Trench .... 

Pit.. ...

...do.. 

Trench 

(see pi. 12,^4.) 

... do.. 

Pit........

...do-- 

...do......

... do.- 

... do-. 

...do-. 

... do.. 

... do.. 

...do..- 

...do-. 

 do-- 

... do.. 

si "o.

o>

p

Ins. 

?4

18

30

24

?4

4?

48

36 

30

30

42

36

48

40

4?

4?

4?!

3fi

36

36

trenches Length of 

Ft.

4

10 

6

£ 

S

°%

l§

| 

fc

3

2

2

3 

3

5

5

4 

3

3

3

3

3

3

3

3

3

2

?,

?:

Rating of tests

TS 

o

o 

O

1

'1 

«1

 3 

h

1

2 

2

1

1

IP

1

"2" 

1

1

1

2

"Negative"

3 

2 

2 

2 

1 

3 

1

1 

3 

1 

3 

1 

3 

3 

3 

3 

3 

2 

2 

2

Remarks

This locality is the first area 

of "white hills" specifically designated by the 

engineer as a place where 

he procured rich samples.

This locality is the second 

area of "white hills" specifically designated by the 

engineer as a place where 

he procured rich samples.

Areas southwest of Shoshone

[See fig. 3 and pi. 11, A]

X< .

Xt .

X«.. .

1 -do... -. 

I do.. 

1 do.. 

(volcanic).

stone (ash). 

[White saline sand1 stone (ash).

I Coarse sandstone..

Pit. 

...do-. 

... do. 

 do.. 

Pit. 

... do.. 

3 pits.-...

3fi

36

36 

36

48

?4

t)A

24

 

....

<««

'6

 -

3

3

3

16

1 9

3

3

9

1

1

....

 -

1

....

1

 -

1

1

1

....

1

1

1 

1

16

12

?,

9

This locality is just off the 

Ratliff claims, but the

ground fairly represents a

treme eastern and southland.

The white-ash bed found

barren of nitrate is probably the bed that is altered

Shoshone hot springs.

0 Many of the beds designated white sandstone are largely volcanic ash. 

» Sample saved for analysis (No. 1). 

 Sample saved for analysis (No. 2). 

' Length of each trench.

Total number of pits dug, 26; total number of trenches, 12; total length, 74 feet.

Tests made, 114 "good," 6; "fair," 9; "weak," 11; "negative," 88.

Every pit and trench was dug deep enough to penetrate into the bedrock (clay, sandstone, or conglomerate) under the loose surface soil. All reactions for nitrate were obtained in the loose soil layer, generally 

just above the upper surface of bedrock. In every excavation the bedrock itself gave "negative" or nearly 

negative tests for nitrate.

In addition to the intensive work tabulated above between 150 

and 160 more field tests were made for nitrate in the course of reconnaissance traverses to and fro across the Ratliff claims. In this work 

the outcrop of every bed exposed in the lake-bed series was tested at
70 NITRATE DEPOSITS IN SOUTHEASTERN" CALIFORNIA

one point or another, some beds at many points. For each test a 

small pit was dug deep enough to reach bedrock, and both the soil 

layer and the bedrock in each hole were tested. In this reconnaissance only six reactions for nitrate were obtained that could be rated 

as high as " fair," and only ten as high as " weak." The rest were 

negative or practically negative. No reaction better than " weak " 

was obtained in bedrock. Nearly every test in bedrock was 

" negative."

SUMMARY OF TESTS

In over 265 tests made in all parts of the Ratliff ground only three 

reactions were obtained that might be expected to indicate the 

presence of as much as 2 per cent of sodium nitrate in the material 

tested. These were rated " good." To check the field ratings samples 

of the material which had yielded two of the " good " reactions 

were saved and sent to the chemical laboratory. Samples of the 

same material were also saved for bacterial tests. Sample No. 1 

(see table) was found to contain 0.32 per cent of sodium nitrate, 

and No. 2 0.36 per cent. These analyses show that the field ratings 

were too high. These two samples represent the best material found 

in any part of the Ratliff claims. The excavations from which the 

samples were taken are shown on Plate 12, A.

Most of the reactions for nitrate on the Ratliff claims were obtained 

in the lower part of the surface soil layer and can not represent 

material that averages over a foot in thickness. Although the bedrock was penetrated at every place where tests of the surface soil 

layer were made, only " negative " or nearly negative reactions were 

obtained from the bedrock at every place.

CONCLUSIONS

1. The Ratliff claims contain no deposits of commercial nitrate, 

either as caliche or in bedrock.

2. The relatively low saline content of the lake beds on the claims 

renders it exceedingly unlikely that they contain valuable amounts 

of potash or other soluble saline materials.

CAVE DEPOSITS

At a point about 100 feet northeast of the east quarter corner of 

sec. 13, T. 22 N., R. 6 E., there is a small cave in a bed of conglomerate. The locality is in the first group of " white hills " designated by the engineer, marked X2 on Figure 4. The floor of the 

cave is covered with earthy material that gives a " strong " reaction 

for nitrate. The material is adjacent to a rat's nest and is full of 

rat manure. The nitrate is probably derived from this source. No
EBERENZ-BEACH NITRATE CLAIMS, AEIZ. 71

trace of nitrate was found in the conglomerate. Although the material evidently contains a high percentage of nitrate, it is obviously 

a deposit of cave nitrate and of no commercial significance. It was 

therefore not included in the tabulation. Other similar cavities exist 

in the lake beds, and it is possible that some of the rich samples 

reported from the claims may have come from them.

In sec. 36, T. 22 N., K. 6 E., about 1% miles west of Shoshone, 

there is an area covered by tuffs and interbedded lavas of Tertiary 

age. (See fig. 3.) At places under small overhanging ledges in 

the tuffs there are thin crusts of white saline material which gives 

"good" reactions for nitrate. A sample.of this material was saved 

for analysis and was found to contain 1.72 per cent of sodium nitrate. 

The tuff itself a few inches beneath the saline crusts gave no reaction 

for nitrate. Evidently the nitrate is a superficial deposit and of no 

commercial importance. At some places the tuff is covered by a 

loose soil which contains a small amount of white saline material. 

This material, however, gave " negative " or only " weak " reactions 

for nitrate. Inasmuch as these occurrences of nitrate are outside 

the Katliff claims and moreover are not commercially valuable, they 

were not included in the tabulation.

BED OF VOLCANIC ASH

At the time of examination the white ash bed (see pi. 12, Z>), 

which later was found to be altered to bentonite near the Shoshone 

hot spring, was being prospected by Mr. Fairbanks in numerous open 

cuts just west of Shoshone (locality X7 , fig. 3). The bed was tested 

for nitrate at many places in these excavations but yielded no reaction. These tests were not included in the tabulation, because the 

locality is outside the Katliff claims.

EBERENZ-BEACH NITRATE CLAIMS, NORTHEAST OP 

SAN SIMON, ARIZ.

At several times during 1917 and 1918 the occurrence of a deposit 

of sodium or potassium nitrate northeast of San Simon, Ariz., was 

reported to the Geological Survey. The last report was made in 

connection with an application for a permit to prospect for potash 

and nitrates filed in the names of George B. Eberenz and L. B. 

Beach.

, LOCATION

The Eberenz-Beach nitrate claims lie in the foothills of the Peloncillo Mountains 7 to 10 miles northeast of San Simon, a station on 

the Southern Pacific Railroad. The altitude of San Simon is about
72 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

3,600 feet, and the claims lie at about 4,300 to 5,000 feet. Their location and extent is shown in Figure 5.

GENERAL GEOLOGY

The Peloncillo Mountains consist in this district chiefly of lavas, 

tuffs, and breccias of Tertiary age. In the vicinity of the claims 

acidic volcanic rocks rhyolitic tuff, rhyolite, and obsidian are the 

prevailing types. The structure appears to be rather simple. The

R.30E. R. 31 E. io9°io' R.32 E.

R.30E. R.3IE. I09 '°

EXPLANATION

R.32 El.

Section corner 

found

Approximate outcrop of beds 

of rhyolite tuff prospected 

for nitrate

Location of 25-foot 

tunnel in the tuff

FIGURE 5.< Map showing location of Eberenz-Beach. nitrate claims, near San Simon, Ariz.

rocks are cut by a few faults and have suffered a certain amount of 

disturbance, but as a rule the beds of tuff and flows of rhyolite dip 

gently or lie nearly horizontal. The geology of the San Simon 

Valley, which lies along the western base of the Peloncillo Mountains, has been described by Schwennesei*,62 but the area covered by 

his report does not extend into the mountains.

** Schwennesen, A. T., Ground water in San Simon Valley, Arizona and New Mexico: 

U. S. Geol. Survey Water-Supply Paper 425, pp. 6-9, 1917.
EBERENZ-BEACH NITRATE CLAIMS, ARIZ. 73 

SUPPOSED MODE OF OCCURRENCE OF THE NITRATE

The nitrate deposit which Messrs. Eberenz and Beach proposed to 

develop is a great bed or, more exactly, a series of beds of tuff which 

underlie the greater part of the ground included in the claims. The 

tuff crops out over an area of considerably more than a square mile, 

its exposed thickness is more than 500 feet, and it dips 3°-15° W. 

(See pi. 15, 0.) It comprises, therefore, a vast tonnage of material 

that could be mined or quarried at the surface. The tuff was believed by the men interested in the claims to be impregnated throughout with a small amount of sodium and potassium nitrate, averaging 

perhaps between iy2 and 2 per cent. Their belief that the tuff is 

impregnated with nitrate and that it thus constitutes a low-grade ore 

of nitrate was based on the following considerations:

1. Many samples rich in nitrate have been found in protected 

places on outcrops of the tuff, whereas no rich samples have been 

found in similar situations on outcrops of other types of rock in 

the vicinity. These rich surface showings were believed to represent 

surface concentrations derived from nitrate contained in the tuff, 

the nitrate having been leached from the body of the tuff by percolating ground waters or by capillary moisture and deposited at 

the surface by evaporation.

2. Analyses of samples of the tuff taken by Mr. Eberenz and his 

associates at depths as great as 25 feet showed small percentages of 

nitrate.

WORK DONE

The tuff beds have been prospected in many open cuts and in one 

tunnel driven 25 feet into the rock. Most of the open cuts were 

made by blasting great spalls off the face of the tuff in such a way 

as to expose the fresh rock to depths of 5 to 10 feet. The tuff in 

these open cuts was sampled at the time the cuts were made, and 

analyses of some samples were said to show amounts of nitrate ranging from 1 to 4 per cent. The tunnel was sampled by Mr. Eberenz in 

February, 1918. A 200-pound sample cut from the east wall and 

representing an average of the tuff from the portal of the tunnel to 

the far end was pounded up, quartered on canvas, and averaged 

down to a 1-pound sample. An analysis of this 1-pound sample 

showed a content of sodium and potassium nitrate together amounting to 1.77 per cent.

EXAMINATION

Three days in the fall of 1918 was spent in an examination of these 

claims, during which the writer was accompanied by George B. 

Eberenz, of Pueblo, Colo.; E. E. Lee, of Paradise, Ariz.; and H. 

Click, of Kodeo, N. Mex., who had done most of the exploratory 

work on the claims.
74 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

THE TUFF

A fair idea of the appearance of the outcrops of tuff at the localities where most of the prospecting and sampling has been done is 

given in Plate 15, C. The beds shown crop out in the steep south 

slope of a hill in sees. 31 and 32, T. 12 S., R. 32 E., and their exposures extend continuously for more than a mile in an easterly 

direction along the south face of the hill.

The tuff is characteristically fine-grained, and the fresh rock 

appears compact. Some beds are much more indurated than others, 

and these harder beds form cliffs. Most of the tuff contains a great 

deal of very fine-grained pinkish material which is almost claylike in consistency and gives color to the fresh rock, but the tuff 

weathers brown on exposed surfaces. Much of this material is 

distributed through the tuff in little lenses that give the rock a 

blotched appearance and weather out readily, leaving innumerable 

little cavities. Some parts of the tuff contain numerous large fragments of volcanic rock, chiefly rhyolite, and are practically a volcanic breccia or agglomerate, but most of it is composed of fine 

material. None of the component material shows evidence of sorting or sizing, and the separate beds of tuff do not exhibit lamination. 

Notwithstanding the compact appearance and feel of the tuff it is 

said to drill easily. Fragments of the freshly dug rock soon disintegrate or slack when exposed to the weather and moistened by rain, 

and the pinkish color changes to white. On the whole the texture 

of the tuff appears to be uniformly and rather finely porous and 

might well favor impregnation by nitrates and other soluble salts. 

The beds of tuff weather into exceedingly cavernous forms and crop 

out in a succession of cliffs, steep slopes, and narrow ledges. Most 

of the ledges are overhung by cliffs in such a way as to protect them 

from the weather and form alcoves. (See pi. 13, J., B.) The 

huge scale of the shelves and caverns formed by these ledges and 

alcoves is not well realized from the photographs. A number of 

them contain small cliff dwellings.

On roofs of alcoves. The roofs of a number of alcoves contain 

saline deposits very rich in nitrate. The rock in such places is considerably weathered and spalls off readily in flakes. Between these 

flakes are crusts of milky crystalline salts. Nearly every sample 

of these salts yields " very strong " reactions for nitrate. This condition persists from 6 inches to a foot into the rock that forms the 

roofs of the alcoves; beyond that zone the rock is compact, appears 

fresh and unweathered, and gives " negative " or only " very weak " 

reactions for nitrate.
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 12

. PROSPECT IMTS AM) TKKiNCII, HATL1KF (CLAIMS

i!. \OLCAMC ASH 1[\ l,,VkE 1SKDS NEAR SHOSHOME
IT. S. GEOLOGICAL SURVEY BULLETIX 820 PLATE 13

A. CLIFFS OF RHYOLITE TUFF ON EBERENZKKACH CLAIMS

a. Roof of alcove; b, back wall; c, loose material under 

overhanging ledge

li. ALCOVE IN RHYOLITE TUFF

Harder inateria over softer. Shows mode of occurrence of nitrate, a, Flaky areas; b, nitratebearing cavities.
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 14

A. HUNGERFORD-MOORE NITRATE CLAIMS

, Breccia (so-called "blowout"); h, mouth of tunnel; c, mouth of shaft; d, dump from tunnel

and shaft.

B, MOUTH OF TUNNEL SHOWN IN A 

Shows cavernous nature of breccia, a, Cavity containing
EBERENZ-BEACH NITBATE CLAIMS, ABIZ. 75

At places on the roofs of the alcoves small cavities in the tuff that 

range in diameter from half an inch to 3 inches are filled with milky 

crystalline salts so rich in nitrate that they will sputter when 

touched with a glowing match or lighted cigarette. (See pi. 13, B.)> 

" Very strong " reactions were obtained from all of this material 

tested; probably most of it contains at least 30 per cent of nitrate. 

In these situations the rock might be likened in appearance to a. 

porphyry in which the numerous little pockets of nitrate-bearing 

salts correspond to the phenocrysts. The salt-filled pockets, however, are superficial, for excavation .shows that they do not extend 

more than a few inches into the mass of the rock.

On back walls of alcoves. The back walls of alcoves here and 

there have coatings or crusts not over an inch thick of milky crystalline salts which do not differ in appearance from the salts in the 

pockets just described but which give only " weak" to " fair" reactions for nitrate. (See pi. 13, A.) At some places these penetrate the rock in veins. The filtrate from this material yields a 

dense white flocculent precipitate (CaS04 ?) in the test tube when 

ferrous sulphate is added.

On -floors of alcoves. The floors of many alcoves are covered to a

' depth of 1 to 2 feet with earthy material formed apparently by the

disintegration of fragments of weathered rock that have shelled off

and dropped from the roof. (See pi. 13, A.) At most places this

earthy material gives " very strong " reactions for nitrate.

Analyses. The material in all the rich surface showings just described is nowhere sufficiently abundant to be commercially valuable, and it is not so regarded by the men interested in the claims. 

However, for record and to get an idea of the nitrate content, one 

sample was saved of material from each of the three types of deposit described and sent to the chemical laboratory of the Geological 

Survey for analysis.

Analyses of samples of surface deposits on Eberenz-Beach claims 

[R. K. Bailey, analyst]

Material

Incrustations of milky crystalline salts from 

roof of alcove to depth of about 6 inches. 

(See pi. 13, J3.)

Incrustation of milky crystalline salts on 

back wall of an alcove. (See pi. 13, A.)

Earthy material covering floor of an alcove. 

(See pi. 13, A.)

Nitrate as 

NaNOs 

(percent)

"34.84

.65

32.70

Remarks

Tuff weathered to a depth of about 6 inches; 

can be pried off in flat slabs or shells. Cracks 

filled with milky salts; "very strong" reaction 

for nitrate. Sample represents 3 pounds of 

saline incrustations divided down to 1 pound.

Gives "fair" field test for nitrate.

Gives "very strong" field test for nitrate.

" R=Na with some Ca. 

3201 31 -6
76 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

No samples were taken of the milky crystalline salts in the little 

cavities or pockets in the tuff in the roofs of alcoves, because the 

material in all of them flared up so quickly when touched with a 

lighted cigarette that there could be no doubt concerning its richness 

in nitrate.

Origin. Several hypotheses as to the origin of the accumulations 

of nitrate just described suggest themselves. All assume final concentration in protected situations by evaporation of percolating 

ground water or capillary moisture.

1. That the nitrate has been derived entirely by nitrification of 

guano deposited in caves in the rock by rodents.

2. That it has been formed in weathered rock and soil near the 

surface by the action of nitrifying bacteria.

3. That it has been formed near the surface by either or both of 

the two agencies just suggested, then carried down into the body of 

the tuff by percolating ground water (rainfall) and deposited there, 

leaving the tuff impregnated with small amounts of nitrate.

4. That the nitrate, like the tuff, is of volcanic origin and the tuff 

is impregnated with it; the impregnation may have taken place 

when the tuff was deposited or later; the rich surface accumulations t 

of nitrate represent material leached from the tuff.

From examination of the nitrate deposits in the crusts and small 

cavities on the roofs of alcoves and the deposits on the walls of 

alcoves it seemed quite out of the question to ascribe the origin of the 

nitrate in these situations directly to accumulations of bat, rat, or 

other rodent guano, because the nitrate deposits are in places where 

the natural deposition of guano would be physically impossible. It 

was equally difficult to see how the nitrate could have reached its 

present position by leaching from any places where guano had decomposed. Moreover, the amount of guano in sight anywhere near 

the deposits is insignificant and seems utterly inadequate to account 

for the nitrate. Small accumulations of guano were noted in a very 

few caverns that could be readily reached by animals, but no more 

than may be found in caverns in rocks of all kinds anywhere in 

the desert region. Undoubtedly some of the niter-bearing earthy 

material on the floors of alcoves has been enriched from this source, 

but most of it has obviously derived its nitrate from nitrate-rich 

material that has fallen from the roofs of the alcoves.

Hypothesis No. 1 may therefore be ruled out as inadequate to 

explain the origin of the deposits. Hypothesis No. 4, which assumes 

that the body of the tuff is impregnated with nitrate, is the view 

held at that .time by the men interested in the_, claims, and their 

expectations as to the value of the property were based upon it. 

They believed that the nitrate is of volcanic origin.
EBERENZ-BEACH NITRATE CLAIMS, ARIZ. 77 

NITEATE IN THE TUFF

The tuff itself received most attention in the examination, because 

it was regarded as the principal body of nitrate ore and because the 

surface showings, though rich in nitrate, are clearly not in commercial quantity. The tuff was tested where exposed beneath the surface in the excavations already dug.

Tests in open cuts. All the open cuts had been directly exposed 

to the weather for periods ranging from one to four years. Chips 

of the rock were cut at several depths beneath the original surface 

in each excavation and tested for nitrate after being pulverized. 

Most of the chips gave no reaction for nitrate, but some yielded 

" weak " reactions. These reactions were generally obtained from 

the chips cut at places near the original surface. None of those 

obtained were strong enough to indicate more than a small fraction 

of 1 per cent of nitrate in the material tested. Because the cuts are 

all exposed to the weather it would be impossible to say whether 

these poor results were due to the leaching of the rock or to the 

actual poverty of the rock in nitrate. Therefore no samples for 

analysis were taken from these open cuts.

Tests and samples in tunnel. The 25-foot tunnel is in relatively 

soft tuff beneath a harder, cliff-forming bed near the base of the 

exposed section of the tuff series, which forms the roof. (See pi. 

15, C) and fig. 5.) The deeper part of the tunnel had been dug 

about 18 months before this examination, and the first 10 feet from 

the portal had been dug several years earlier, but as all the rock of 

its Avails is protected from the weather and is dry, the tunnel afforded as fair an opportunity to test the tuff as it did when dug. The 

results of Mr. Eberenz's sampling are given on page 75.

The Geological Survey party first made tests of the rock in the 

face of the tunnel, 25 feet from the portal. The tests were difficult 

to make because the rock when crushed, pulverized, and moistened 

forms a mud which is exceedingly difficult to filter. The scanty filtrate from these crushed and pulverized samples of the rock gave no 

reaction for nitrate. Filtrate from uncrushed chips of the rock likewise gave " negative " reactions. Chips of the rock at different 

places along the walls of the tunnel were tested with similar results. 

Two or three chips cut near the portal gave very faint, almost imperceptible reactions, which could not be rated better than " very weak." 

Thus no reaction was obtained anywhere in the tunnel that could be 

considered indicative of more than a trace of nitrate in the material 

tested.

Three samples of the rock in the tunnel were taken as a check and 

sent to the chemical laboratory of the Geological Survey for analysis. 

The first sample was taken to show roughly the average nitrate content of the tuff for the length of the tunnel. It consisted of small
78 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

chips cut from the east wall in a strip extending from the end to a 

point about 2 feet from the portal. It represented .roughly, but in 

very much smaller quantity, the material constituting Mr. Eberenz's 

200-pound sample. As a. further check Mr. Eberenz himself, on 

request, cut this sample. It was a fair average sample for its weight 

but was not nearly so representative of the rock as the original 200- 

pound sample. When analyzed in the chemical laboratory by R. K. 

Bailey it was reported by him to contain no nitrate.

Another sample, which weighed three-quarters of a pound, was 

taken to show roughly the nitrate content of the tuff at the greatest 

depth reached, at the end of the tunnel. It consisted, of chips cut 

from the west wall of the tunnel between the 20 and 25 foot marksMr. Bailey's analysis showed no nitrate.

A third sample, weighing three-quarters of a pound, was intended, 

to show roughly the nitrate content of the tuff a few feet beneath the 

surface, as contrasted with the tuff at a depth of 15 feet on more, 

represented by the second sample. It consisted of chips from the 

west wall of the tunnel between the portal and a point 5 feet within. 

Mr. Bailey found no nitrate in it.

As the analyses of these°three samples agree with the results of 

the field tests in the tunnel, which were practically negative, doubt 

may fairly be expressed regarding the accuracy of the analysis of 

the 200-pound sample cut by Mr. Eberenz, and consequently regarding the impregnation of the tuff with as much as 1 to 2 per cent of 

nitrate. Certainly the negative character of the field tests and the 

absence of nitrate in the samples analyzed creates a strong presumption against the impregnation of the tuff with even a small percentage of nitrate in the part penetrated by the tunnel. On the 

other hand, the Geological Survey samples are so much smaller than 

the one taken by Mr. Eberenz that results obtained from them may 

not be conclusive. Moreover, the sampling of one tunnel does not 

constitute a fair test of the vast body of the tuff.

The apparent poverty in nitrate of the tuff in the tunnel is rendered' 

more impressive by an occurrence of some very rich superficial deposits of nitrate at the mouth of the tunnel. The roof of the alcove 

overhung by a cliff-making tuff bed beneath which the tunnel is 

driven is coated with crusts of saline material that give so stronga reaction for nitrate that they must consist almost wholly of it.. 

Yet the tuff a few feet underground, where exposed in the tunnel,.. 

gives no reaction.

CONCLUSIONS

1. The rich deposits of nitrate-bearing salts in protected places' 

on the outcrops of the tuff do not extend more than a few inches 

into the body of the tuff and are therefore not sufficient in quantity 

to be of commercial importance.
EBERENZ-BEACH NITRATE CLAIMS, ARIZ. 79

2. The value of the property depends on whether the mass of the 

tuff is impregnated with nitrate.

3. The available tonnage of the tuff is unquestionably very large, 

:and the material is exposed in such a way that it could readily be 

mined and quarried.

4. The texture of the tuff is porous and therefore favorable for 

impregnation by nitrate.

5. The rich surface deposits of nitrate in protected situations do 

not necessarily indicate that the tuff itself is impregnated with 

nitrate, because (a) rich surface deposits have been found in other 

regions in protected situations on types of rock other than volcanic 

tuff on limestones, for example; (&) the nitrate may have been 

formed near the surface through the action of bacteria and then

 concentrated in protected situations by evaporation of percolating 

ground water or capillary moisture.

6. If the tuff is impregnated with nitrate, either as a whole or 

in places along cracks and zones, it is reasonable to suppose that the 

rich surface deposits represent niter-bearing saline material leached 

irom the tuff and carried to the surface by percolating water or

 capillary moisture and concentrated in protected situations by 

evaporation. Given time, even traces of nitrate disseminated 

through the tuff would be sufficient to account for these rich surface

 concentrations.

7. Whether the tuff is impregnated with nitrate is not yet definitely known and can be determined only by systematic underground 

exploration and sampling.

8. This work had been begun by Mr. Eberenz and his associates 

but not carried to a conclusion. It represented a systematic and

 conscientious attempt to learn at considerable expense, and possibly 

loss, whether a deposit of this type has any promise as a low-grade

 ore of nitrate. Results obtained by Mr. Eberenz and his associates 

indicated that the tuff contains between iy2 and 2 per cent of nitrate.

9. The Geological Survey's results are adverse to the conclusion 

that the tuff is impregnated with nitrate; they indicate, indeed, that 

the parts of the tuff tested are practically barren of nitrate. They 

.are not regarded as conclusive, for reasons already stated. Before 

final conclusions are reached other parts of the tuff should be tested 

in tunnels driven at least 15 feet into it.

10. If further prospecting is carried on it would be worth considerable effort and expense to get therefrom conclusive evidence as 

to the origin of the nitrate, because the deposit is a fair sample of 

hundreds of others of the same type in the western United States 

which have likewise been prospected Avith unsatisfactory results and 

.abandoned before a definite conclusion as to origin and value could
80

be reached. Work on the deposit should therefore be watched with 

interest.

11. In view of the results already obtained, however, further work 

should be undertaken only with a full understanding of the expense 

and the highly speculative risk involved.

R. 18 W. ' 32*

1D»°00* R.21 W. R.I9W. .a08°45'

10 Miles

FIGURE 6. Map showing approximate location of Hungerford-Moore nitrate claims (X),.

Animas Valley, N. Mex.

HUNGERFORD-MOORE NITRATE CLAIMS IN ANIMAS 

VALLEY, N. MEX.

LOCATION AND ACCESS

The Hungerford-Moore nitrate claims lie in Hidalgo County, N.. 

Mex., about 20 miles south of Animas station on the Southern PacificRailroad, as shown in Figure 6. The property was discovered by
HUNGERFORD-MOORE NITRATE CLAIMS, N. MEX. 81

John Moore, a miner and prospector well known in the Animas 

Valley. Moore brought it to the attention of D. H. Pemberton, 

under whom he was working in Searchlight, Nev., and through 

Pemberton to C. B. Hungerford, of Newmark, Calif. These three 

men are associated in the project, but Moore has done the locating 

and most of the prospecting and sampling.

In company with E. E. Lee, of Paradise, Ariz., the writer visited 

and examined the property on November 22, 1918.

The claims are 4 miles south of the Dunnigan ranch, a well-known 

place in the upper Animas "Valley 16 miles south of Pratt, on the 

mail route south from Animas station to Cloverdale, near the Mexican border.

The altitude as indicated by a barometer reading checked against 

the altitude of the railroad station at Kodeo, is 5,100 feet.

Q>

GENERAL GEOLOGIC FEATURES

The ge'ology of the Animas Valley has been described by 

Schwennesen.63 The Animas Valley at the point where the claims 

are located is wide and open, with the dry bed of the river about in 

the center. Animas Peak rises several miles to the southeast, and the 

Peloncillo Mountains a corresponding distance to the west. The 

west bank of the river here is a steep rocky slope that rises perhaps 

200 feet above the stream bed, but the east bank is simply a low 

bluff some 20 feet high, cut in the alluvial filling of the valley. No 

bedrock is exposed in the east bank or in the bed of the stream. 

The steep slope on the west side is practically all an outcrop of 

light gray, rather massive acidic volcanic rock, apparently rhyolite, 

dacite, or latite porphyry; it is probably an outlier of the volcanic 

rocks of the Peloncillo Mountains. The exposure extends half a 

mile or more along the stream.

About in the middle of this exposure, near the base of the rocky 

slope, is a curious mass of cavernous rock locally termed a " blowout." 

(See pi. 14, A.) Viewed from a distance it looks like a hot-spring or 

geyser deposit, but on examination it proves to be a coarse cavernous 

breccia. (See pi. 14, B.) The fragments in the breccia resemble 

the porphyry on the steep slope back of the " blowout," but they 

have a pinkish color and appear to be more or less silicified. The 

matrix in which the fragments lie is a fine whitish or pinkish material which forms perhaps somewhat less than half the mass of the 

breccia. The cavernous nature of the breccia is due to the weathering out of this powdery material from between the fragments.

The outcrop of the breccia is about 160 feet long and 120 feet 

wide. The depth of the mass and its probable form are unknown.

88 Schwennesen, A. T'., Ground water in the Animas, Playas, Hachita, and San Lula 

Basins, N. Mex.: U. S. Geol. Survey Water-Supply Paper 422, pp. 28-36, 1018.
82

Possibly it is a sort of vertical pipe in surrounding porphyry. The 

lowest part of the outcrop is perhaps 50 feet above the level of the 

stream bed.

REASON FOE THE EXAMINATION

Samples taken from the deposit were submitted to the Geological 

'Survey by Mr. Hungerford in 1914, together with a letter containing 

the following description:

It apparently has been a river or lake bed. We have six claims and have done 

some development work outside of location work. There is a range of hills 

and low mountains on either side. The vein or ore deposit seems to be about 

:200 feet wide, but of course this is so near the surface it is impossible to tell 

how wide it really is. The older diggings seem to have the most crystals in 

rsight that is, there seems to be a pressure from the inside of a fluid impregnated with potash that shows in the shafts that are the oldest, as the fresh 

moved rock and earth do not show the coating of potash that some of these 

samples show. The finer particles in the sack are from the recent workings, 

and although they do not show the white coating the analyses are very good. 

We wish to go on with our development work and verily believe with depth 

~we have a large body of good grade of nitrate. We have had some very good 

analyses made by responsible firms. We would like to give this property a. 

thorough testing, drilling holes to a depth of 200 feet and sampling the product

 every 10 feet or oftener.

The samples sent to the Geological Survey proved to be a little 

more than one-half soluble in water. Approximately two-thirds of 

'this soluble material was potassium nitrate; no chloride and only a 

small amount of sulphate was present. The samples, then, were 

relatively rich in nitrate.

A personal call on Mr. Hungerford elicited the information that 

the nitrate was " in a pinkish conglomerate " and was found " in 

crystals on the conglomerate." He said that some samples showed a 

content of potassium nitrate at a depth of 16 feet in an excavation. 

According to his recollection, one sample ran 32.6 per cent of sodium 

nitrate and 36.4 per cent of potassium nitrate.

Apparently, then, from their statements the locators of the property considered the mass of pinkish cavernous breccia, or " blowout," 

above described, the " vein or ore deposit." (See pi. 14.) They 

'believed that somewhere in the breccia there is a " large body of 

good^grade nitrate " and they based their expectations on the fact 

that they had found rich samples of sodium and potassium nitrate 

on the surface of the " older diggings " and some fair samples " in 

the recent workings."

EXAMINATION

There is a 30-foot shaft in the breccia in the lower part of the

 outcrop, about 50 feet above and perhaps 150 feet west of the creek

 bed. A great ledge of cavernous breccia overhangs the mouth of the
HUNGERFORD-MOORE NITRATE CLAIMS, N. MEX. 83

shaft and almost entirely protects it from the weather. At the 

mouth of the shaft a tunnel has been driven westward about 30 feet 

directly into the breccia.

According to Mr. Dunnigan, the numerous cavities in the breccia 

once contained considerable cave niter, which has been practically 

all cleaned out and taken away. It is possible, therefore, that this 

material is the source of some if not most of the rich samples 

obtained by the locators. No attempt was made to sample it 

because, owing to its nature, its superficial character, and its small 

quantity it is obviously of no importance as a source of commercial 

.nitrate.

The 30-foot tunnel afforded an excellent opportunity to examine 

the breccia underground. Accordingly the breccia was tested at 

many places in the tunnel and its exposures in the walls were carefully examined. No veins or shoots of nitrate were seen in the 

breccia, nor could any evidence of their existence be found. The 

fragments of siliceous porphyry that make up the greater part of the 

breccia furnished no reactions for nitrate. These porphyry fragments are so dense and solid that it is inconceivable that they could 

contain more than the smallest traces of soluble saline material. It 

was therefore evident that if the breccia contains any considerable 

amount of nitrate, the nitrate either impregnates the matrix of 

whitish or pinkish powdery material in which the porphyry fragments are embedded or lies in caverns or pockets in the breccia. The 

powdery material was next tested. From it " weak " reactions for 

nitrate were obtained at two places in the tunnel, but no reactions at 

other places. To check these field tests two samples of the material 

that gave reactions were sent to the chemical laboratory for analysis. 

Sample 1 represented about a pound of the powdery material that 

forms a matrix of the breccia, gathered from a strip 5 feet long^ 

at the far end of the tunnel. The powdery material is not continuous 

in this strip; it was picked out from between the fragments of solid 

porphyry that are embedded in it. Sample 2 represented a pound 

of similar material gathered in the same way from a strip 5 feet 

long midway between the portal and the end of the tunnel.

As analyzed by E. T. Erickson, sample 1 contained only tracesof N03 and of soluble K, and sample 2 contained 0.5 per cent of N0» 

and a trace of soluble K.

These results may indicate that at some places the. powdery matrix: 

of the breccia contains a little nitrate, although the amount is 

evidently much too small to be of commercial significance. On the 

other hand, it is not at all unlikely that the material tested and 

sampled in the tunnel had been contaminated by cave nitrate or by 

nitrate derived from deposits of guano. Several large cavities in*
84

the breccia are cut by the tunnel; according to Mr. Dunnigan these 

cavities contained deposits of cave nitrate when the tunnel penetrated 

them. At the time of examination a pile of guano 2 feet high and 

4 feet in diameter lay upon the floor of the tunnel under a bat roost 

on the ceiling near the end of the tunnel. Similar accumulations 

were noted in several natural caverns in the breccia. Some of the 

material had evidently nitrified in place.

It was not clear whether by " the older diggings " the locators 

meant the tunnel or the shaft, or both. It may well have been 

possible originally to obtain rich samples of cave nitrate in either 

one, because the breccia is cavernous in both, or to obtain rich 

samples in the numerous cavities in and about the great natural 

alcove where the tunnel and shaft are dug. It therefore seems 

probable that the rich samples referred to by Mr. Hungerford 

represented material of the cave-niter type like the material on 

roofs, walls, and floors of alcoves on the Eberenz-Beach nitrate 

claims, described on pages 74-Y5. Very little of this material remained in the cavities, however, at the time of this investigation. No 

evidence could be seen that the walls of the tunnel are being 

impregnated at the present time by a fluid containing potash or 

nitrate; the walls were dry; there was no coating or bloom of 

efflorescent salts upon them and no evidence of seepage through 

them.

The shaft was not accessible, but it could be seen that the walls 

were in the same sort of material as the tunnel and that there was no 

evidence of seepage into the shaft at that time from the sides or bottom, which were dry. The property was visited at the end of a two 

days' storm of snow and rain, which had thoroughly soaked the region. Although the mouth of the shaft was protected from the 

weather by an overhanging ledge of cavernous breccia the situation 

is such that a very heavy rain if driven by high wind from the east 

might leach cave nitrate from the overhanging ledge and wash it 

down over the walls of the shaft. Whether this had happened is not 

known, but it is possible, and if some rich samples came from the 

walls of the shaft, which, as Mr. Hungerford seems to state, did not 

show nitrate when the shaft was first dug, the nitrate may have 

been deposited later upon the walls in this way. No reaction for nitrate was obtained from material lying on the dump heap composed 

of material thrown out in digging the tunnel and shaft. However, 

this material had been exposed directly to the rains for a long time 

and was probably thoroughly leached of any soluble salts that it may 

have contained.

It is possible that the nitrate occurs in some form or situation that 

has been overlooked through some misinterpretation of the statements of the locators, but from conversation with Mr. Dunnigan,
RANDOM TESTS IN AREAS OF TERTIARY STRATA 85

who lives near the property and is familiar with it, this does not 

seem to be true. According to Mr. Dunnigan, there are similar 

" blowouts " in the Peloncillo Mountains, west of the property, and 

deposits of cave nitrate occur in cavities in them.

CONCLUSIONS

The mass of breccia which, from statements of the men interested 

in the property, seems to constitute the " vein or ore " of nitrate is 

clearly not large enough to be of commercial importance unless it 

contains large bodies of nitrate in veins or shoots or is impregnated 

with a considerable percentage of nitrate. No indications could be 

found in a tunnel driven 30 feet into the breccia that veins or shoots 

of nitrate exist in the rock.

Tests and samples of the breccia exposed in the tunnel might be

 considered to indicate that the breccia is impregnated with a small 

percentage of nitrate, but it is at least as likely that the material 

sampled has been contaminated by nitrate derived from guano 

deposits in the tunnel. If the breccia is impregnated with nitrate, 

the average percentage must be very low, for the best sample showed 

.a nitrate content of only 0.5 per cent. This amount is far too low to 

be of commercial importance. No other field test in the tunnel indicated as much as this amount; indeed, most tests in the tunnel were

 " negative." Moreover, nitrate if present as an impregnation in the 

.breccia could be contained only in the powdery material that forms 

the matrix of the breccia, for the fragments of porphyry that are

 embedded in the matrix can contain no soluble saline material. Inasmuch as these porphyry fragments constitute at least half of the 

mass of the breccia the percentage of nitrate shown in samples taken 

must necessarily be reduced one-half .if it is to represent the content 

of the mass of the breccia.

The only material relatively rich in nitrate seen on the property 

is of the " cave nitrate " type. It occurs in protected situations on 

ro.ofs, walls, or floors of cavities in the breccia but is superficial and

 .therefore of no commercial importance.

As the writer was not accompanied by any of the men interested 

in the property, it is possible that the nitrate occurs in some form 

or situation that was overlooked.. If for example, it occurs in veins 

or as concentrations within the mass of the breccia the property 

would be worth further prospecting.

RANDOM TESTS IN AREAS OF TERTIARY STRATA

At several times since 1918, while traveling through areas of 

Tertiary strata that resemble the clay-hill areas described in this 

report, the writer has stopped for a few nitrate tests. Although
86 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

these areas were not examined in detail it seems worth while to note 

briefly the results of the tests.

VALLEYS OF MUDDY CHEEK AND VIRGIN RIVER, NEV.

The lower valley of Muddy Creek and the valley of the Virgin 

River below St. Thomas contain many exposures of a series of 

loosely consolidated beds of sandy clay, sand, and gravel, which at 

most places are horizontal or nearly so but at some places are moderately tilted and folded. This series of beds, named the Muddy 

Creek formation by Stock, has been described in detail by Longwell,04 

who assigns it tentatively to the Pliocene. Possibly it is equivalent 

in age to the beds with which nitrate is associated at West Well 

near the Colorado River below Needles, described on pages 38-39. 

Some beds contain much saline material. Many beds contain gypsum, and one bed exposed in the valley of the Virgin River consists 

of solid rock salt. Gypsiferous clay beds are associated with the 

salt bed. At some places the beds of clay or sandy clay are covered 

with a barren clay soil that resembles the soil in the clay-hill nitrate 

areas. At the surface of the ground is a thin layer of compact clay 

furrowed with tiny knobby corrugations. Beneath this clay is a 

layer of loose material consisting of powdery clay mixed with varying amounts of soluble salts. This loose soil, which passes downward into the underlying rock, was tested at a number of places 

near Logan, in the valley of Muddy Creek (see pi. 1), and a reaction 

for nitrate was obtained at each place.65 None of the reactions,, 

however, were better than " weak." At the places tested no caliche 

layer is present at the base of the soil, but in the vicinity of the salt, 

bed exposed in the valley of the Virgin River about 7 miles below 

St. Thomas a hard salty caliche was found resembling that which 

overlies the more saline clays and the salt bed in the Saratoga nitrate 

field.66 The hard, salty caliche is confined to the outcrop of the 

salt bed. Unquestionably, therefore, the salt in the caliche has been 

derived from the underlying salt bed. This caliche was tested at 

one place, but yielded no reaction for nitrate. Several pieces of 

the rock salt were also tested for nitrate, but no reaction occurred.

. FURNACE CREEK, CALIF.

One of the largest and certainly the most spectacular area of 

Tertiary strata in the desert region lies along the valley of lower 

Furnace Creek between Ryan and the floor of Death Valley, the

84 Longwell, C. R., Geology of the Muddy Mountains, Nev.: Am. Jour. Sci., 4th ser., 

vol. 50, pp. 39-62, 1920. See also U. S. Geol. Survey Bull. 798, 1928.

05 Noble, L. F., Colemanite in Clark County, Nev.: U. S. Geol. Survey Bull. 735, p. 31,. 

1922.

66 Noble, L. F., and others, op. cit, p. 39.
RANDOM TESTS IN" AREAS OE TERTIARY STRATA 87

exposures extending continuously for at least 12 miles along the 

south side of Furnace Creek Wash. (See pi. 1.) The area is interesting not only for the odd colors of the strata and the weird badland 

scenery to which these beds give rise but because the strata contain 

many large deposits of boron minerals (colemanite and ulexite). 

The rocks comprise sandstones, conglomerates, clay shales, freshwater limestones, tuffs, breccias, and sheets of lava. They are steeply 

tilted, folded, and faulted and include at least two unconformable 

series whose total thickness amounts to many thousands of feet. 

Many clay beds are very thinly laminated and were evidently deposited in lakes. Many sets of beds closely resemble the strata with 

which nitrate deposits are associated in the Amargosa region and 

were obviously deposited under, similar conditions. Much of the 

Tertiary section on Furnace Creek and much of that in the Amargosa region is probably equivalent in age. In general the section on 

Furnace Creek contains more volcanic material than that in the 

Amargosa region. The beds in both sections, however, were deposited during a period of continuous and violent volcanic activity. 

Many clay beds on Furnace Creek, as in the Amargosa region, consist largely of fine volcanic ash.

Enormous tracts in the Furnace Creek region are intricately 

carved into badlands, and at some places the beds form rounded hills, 

covered with clay soil, which resemble the typical niter hills of the 

Amargosa region. (See pi. 15, A, B.) South of Furnace Creek, 

in the vicinity of Mount Blanco and extending to the edge of Death 

Valley, tracts of this typical clay-hill ground must cover many 

hundreds of acres. It seemed worth while, therefore, to test some 

of this ground for nitrate. Accordingly tests were made at two 

places selected at random, along the road down Furnace Creek.

The first locality is on the north bank of Furnace Creek Wash, 

about half a mile below the tank shown on the Furnace Creek topographic map northwest of the 1,939-foot bench mark. At this 

locality steeply tilted beds of greenish-yellow sandy shale crop out 

in the bank of the wash. At places the outcrops of the shale are 

covered with a barren clay soil. Two pits in this soil disclosed 

compact clay at the surface, 2 inches; powdery clay mixed with 

white efflorescent salts, apparently chiefly sodium sulphate, 1 foot; 

cracked and weathered shale cemented by saline material (apparently chiefly sodium chloride) and resembling the typical caliche 

layer of the Amargosa nitrate fields, 6 inches; and unaltered shale. 

The caliche in both pits was tested. In one pit it gave a " weak " 

reaction for nitrate and in the other a " fair " reaction.

The second locality is on the south bank of Furnace Creek Wash 

about 1.8 miles below the tank already mentioned. Here a tract
88 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

of ground many acres in extent is underlain by whitish or creamcolored shales that dip steeply and at some places stand nearly 

vertical. Two pits were dug in this ground. (See pi. 15, A.} 

Both revealed the same arrangement as in the first locality compact clay at the surface, 3 inches; a powdery saline layer, 4: inches; 

caliche, 4 inches; and unaltered shale. The ground proved to be 

remarkably similar to that at Bully Hill, in the Upper Canyon 

nitrate field.67 Samples of caliche from both pits yielded " fair " 

reactions for nitrate.

These random tests on Furnace Creek, all of which yielded a. 

reaction for nitrate, suggest that much of the caliche in the Furnace 

Creek areas contains nitrate. Inasmuch as the clay-hill ground on 

Furnace Creek is of considerable extent and is similar to that in 

the more promising areas of the Amargosa region, it is possible that 

systematic prospecting in the Furnace Creek area would reveal 

tracts of caliche similarly rich in nitrate.

FISH LAKE VALLEY, NEV.

On the east side of Fish Lake Valley, at the mouth of the canyon 

through which a road descends from Emigrant Pass, are outcropsof tilted beds of Tertiary clay which in places are covered with 

barren clay soil like that in the clay-hill nitrate areas of the Amargosa region. The locality is about 3 miles northeast of the ruinsof the borax mill near " The Crossing," in Fish Lake Valley. (See 

fig. 7.) The altitude is about 5,000 feet. One pit was dug in the 

typical clay-hill ground in this locality, and the arrangement of the 

ground proved to be similar to that in the numerous other clay-hill 

areas already described a layer of compact clay at the surface,, 

2 inches; powdery clay containing much saline material, 1 foot; 

cemented caliche, 3 inches; and unaltered shale. A test of the caliche 

yielded a " fair " reaction for nitrate.

The results of these random tests in three widely separated areas 

of clay strata Muddy Creek, Furnace Creek, and Fish Lake Valley 

indicate that nitrate deposits of the clay-hill type are very widely 

distributed in the desert region and are probably to be found wherever there are any considerable areas of exposed clay strata.

PARTIAL, ANALYSES OP CALICHE FROM THE NITRATE 

FIELDS OF THE AMARGOSA REGION

After the nitrate fields of the Amargosa region had been explored,, 

one sample of nitrate-bearing caliche from each of the four fields

67 Noble, L. F., and others, op. cit, p. 69.
ANALYSES OF CALICHE FROM THE AMAEGOSA REGION 89

most thoroughly prospected was analyzed in the chemical laboratory 

of the Geological Survey to determine the relative amounts of the 

chief salts present in the caliche. Through an oversight these analyses were not included in the Amargosa. report, and accordingly they 

are given below.

The Saratoga and Confidence samples represent the hard, compact salty caliche characteristic of those two fields; the Upper Canyon sample represents the semicompact flaky caliche characteristic

JIB 00' R.36E.

38"00 3800

R38EL.45' R.39E.

10 MILES

FIGURE 7. Map of Fish Lake Valley and adjacent regions, Nev. X, approximate location 

of Tertiary beds tested for nitrate

of the better ground in that field; and the Zabriskie sample represents the crumbly and rather ill-defined layer that lies at the base 

of the soil at some places in that field and corresponds to the caliche 

layer of the other fields. None of the samples analyzed was selected 

with reference to its relative richness or poverty in nitrate. Accordingly none of them represents the best or the poorest material found 

in its field. Each represents, rather, the caliche which in physical 

character is most typical of the field in which it occurs.
90 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA 

Partial analyses of caliche from Amargosa region

Nitrate 

field

Confidence..

Saratoga....

Upper Canyon.

Reference in 

Bull. 724

PI. 15; pp. 54, 55.

PL 8; p. 42......

PL 30; pp. 70, 71.

PL 23...........

No. of 

sample

A-44

S-16

T-12(214)

Z-3

Soluble

salts at 

180° C. 

 (per

cent)

40.35

23.62

13.68

8.17

Na

Much.

Much.

Much.

Much.

Ca

Trace.

Little.

Trace.

K

Trace.

Trace.

Trace.

Cl

14.82

9.60

3.46

2.16

COj

0.15

.04

.03

1,19

S04

8.17

3.61

Little.

Little.

NOj

1.89

-1.57

4.56

.82

0 Nitrate content of this sample erroneously tabulated in terms of NaNOs in Bulletin 724, Instead of in 

terms of NOs.

Calculated salts (per cent)

NaNOs.... --- 

NaCl.. ...... ...... . .. . ..

NaaCOj 

NajSOi.. . 

Total....-- -..------------.-.-.-..--.

A-44

2.59

24.42

.27

12. 08

.99

40.35

S-16

2.17

15.82

.07

5.34

.22

23.62

T-12(214)

6.25

5.70

.05

1.68

13.68

Z-3

 1.12

3.56

2.10

1.39

8.17

a Nitrate content of this sample erroneously tabulated as 0.12 per cent in Bulletin 724, instead of 1.12 

per cent.

These analyses show that sodium chloride is prevailingly the 

most abundant soluble salt in the caliche and therefore the salt 

that may be said to characterize it. In all but one sample, that 

from the Upper Canyon field, the sodium chloride greatly exceeds 

any other salt; and even in the Upper Canyon sample it is nearly 

as abundant as sodium nitrate, the most abundant salt.

The principal other soluble salts present in the caliche are sodium 

nitrate, sodium sulphate, and sodium carbonate, but the amounts 

of these salts fluctuate widely, so that the composition of the caliche 

differs considerably in the different samples. For example, sodium 

nitrate is the most abundant salt in the Upper Canyon sample 

but is only third in abundance in the other three. Sodium 

sulphate is second in abundance in two samples but is absent 

in the other two. Sodium carbonate is second in abundance in one 

sample but is present only in insignificant amounts in the other three.

The results of these analyses, considered in connection with numerous qualitative tests of the caliche and overlying soil made during the several nitrate investigations here mentioned, lead to the 

following generalization concerning the soluble salts present in the 

caliche as contrasted with the soluble salts present in the overlying 

" efflorescent" layer of loose soil. The soluble salts in the soil 

are chiefly sulphates with a subordinate but fluctuating amount of
TJ. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 15

A. TERTIARY STRATA SOUTH OF FUHNACE CHKKK 

View southeast. Typical clay hill. Ground shows absence of vegetation.

13. TERTIAUY STRATA SOUTH OF FUHNACK CHKKK 

View west. Death Valley and Panamint Range in background.

G. PANORAMA OF AREA COVERED BY EBERENZ-BEACH NITRATE CLAIMS

View from wost to east. Arrows show locality of samples 2-4 X, Tunnel and samples 1, 5, and 6; r, rhyolite.
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE IB

A. BLISTER CALICHE ON GREEN SHALE, CONFIDENCE FIELD 

Pits mark width of outcrop of green shale.

B. NEAR VIEW OF REDS SHOWN IN A 

Caliche blister. Hammer head marks characteristic cavity; compass rests on arch of blister.
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 17

A. NITRATE GROUND IN AMPHITHEATER CANYON, SARATOGA FIELD

X, Locality where samples were taken for nitrification tests 3, 4, and 5.

B. EXCAVATION AT LOCALITY SHOWN IN A

a. Surface clay (sample 3); h, efflorescent layer (sample 4); c, caliche (sample 5).
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 18

A. SALT DEPOSIT ON FLOOR OF DEATH VALLEY 

Note the rou^h surface

B. RECENT CINDER CUM-J 1A INOHTH DEATH VALLEY 1NKAR MOUTH OF 

UBEHEBE WASH
U. S. GEOLOGICAL SURVEY BULLETIN 820 PLATE 19

A. STRAND LINES, PANAMINT VALLEY 

East side, 4 miles north of Goler Canyon.

li. STRAND LINES, SOUTH END OF DEATH VALLEY

Cut in basalt hill 2 miles northwest of Ashford Mill.
BLISTER CALICHE PROM THE CONFIDENCE NITRATE FIELD 91

chlorides and an insignificant amount of nitrates; whereas the soluble 

salts in the caliche are chiefly chlorides with subordinate but widely 

fluctuating amounts of nitrates and sulphates. As contrasted with 

the soil and caliche layers, the bedrock strata beneath these layers 

contain a far smaller proportion of soluble saline material. At the 

few places where chemical tests have been made the most abundant 

soluble salt in the bedrock appears to be sodium chloride. Nitrate 

is present at many places but is insignificant in amount, and whether 

it is present at depths below 10 or 12 feet, the greatest depth reached 

in any of the excavations, is not known. The caliche and overlying 

layers, however, constitute a blanket that conforms generally with 

the surface of the ground without regard to the attitude of the 

bedrock strata, but certain types of rock clay beds, for example 

appear to be more favorable for the accumulation of caliche than 

others. At Bully Hill, in the Upper Canyon field, the richest of 

the larger nitrate-caliche areas, some 1,200 feet of inclined strata 

were exposed in prospecting operations without disclosing any bed 

that contained more than a trace of nitrate. There is therefore 

little reason to suppose that beds rich in nitrate occur at depth in 

any of the fields investigated. Insoluble sulphates, chiefly gypsum, 

are present nearly everywhere in the bedrock strata of the clayhill areas and at most places are abundant also in the soil and caliche. 

The rude zonal arrangement of the salts just described soluble 

sulphates characterizing the loose soil layer and soluble chlorides 

and nitrate characterizing the caliche layer appears to be the rule 

in all the clay-hill nitrate deposits.

COMPLETE ANALYSES OF BLISTER CALICHE FROM 

THE CONFIDENCE NITRATE FIELD

One of the essential steps in a systematic study of the origin of 

the clay-hill nitrate deposits is the making of numerous complete 

analyses of the different types of caliche and the bedrock beneath 

the caliche. Although this study was beyond the scope of the 

present investigation it seemed worth while for record to have one 

complete analysis of caliche made. For this. analysis the blister 

caliche of the Confidence nitrate field was selected. (See pis. 1 and 

16.) That caliche was chosen because it is the richest in nitrate 

of all found during the Geological Survey's investigation. The 

blister caliche is confined sharply to the outcrop of a bed of green 

shale at this locality but the bedrock below shows no more enrichment here than elsewhere. (See pi. 16, A.) A 48-pound sample 

of blister caliche taken during the exploration of the Confidence

S201 31 7
92 NITRATE DEPOSITS IF SOUTHEASTERN CALIFORNIA

field yielded 15.63 per cent of sodium nitrate, and two handsorted samples contained 22.18 and 22.21 per cent. The Confidence 

field was revisited in 1921 and another sample of the caliche 

was taken near the locality where the first rich samples had been 

obtained.68 The later sample represented about 25 pounds of the 

caliche gathered at random over an area of about 200 square feet, 

with no attempt to sort the material. It was pounded up on canvas, 

averaged down to about half a pound, and analyzed in the chemical 

laboratory of the Geological Sutvey by R. KL Bailey, with the 

following result:

Chemical composition of blister caliche from Confidence nitrate field, CaliforniaTotal soluble salts_______________________ 43.12 

Insoluble matter_________________________ 49.59

H2O_____ __________________________ 7. 29

100.00

Composition of salts (as per cent of total soluble salts) :

Cl________________________________ 35. 34

SO*__-_________________________ 6.08

NO*________________________________ 23.19

B2Os _^-__________ ________________ . 65

ClOa___________________________:___ Trace.

I ______;_____ __________________ None.

IO3 ______________________________ None.

' Ca__________.________________ . 70

Mg____________-,____________________ .23

K__________________________________ . 51

Na_____________________ ___ 33.30

____________________ None.

100.00

The analysis just given is similar to some analyses of Chilean ca-. 

liche,69 although the blister caliche contains less nitrate than most of 

the Chilean material. Like the Chilean caliche, the blister caliche 

consists chiefly of sodium chloride and sodium nitrate, with subordinate sulphates and chlorides of calcium, potassium, and magnesium, 

and contains a small amount of borate and a trace of chlorate. Indeed, it appears to differ from the Chilean caliche essentially only in 

containing no iodine. However, the composition of the caliche in the 

clay-hill deposits, like that of the caliche in Chile, is known to be exceedingly variable; and one complete analysis of one type of clay-hill

68 Noble, L. F., and others, op. cit., pp. 19, 57.

69 Clarke, F. W., The data of geochemistry, 5th ed.: U. S. Geol. Survey Bull. 770, p. 256, 

1924.
NITRIFICATION TESTS 93

caliche is certainly insufficient to afford a fair standard of comparison. It is possible that other analyses of the clay-hill caliche at some 

other locality may reveal the presence of iodine. Iodine has been reported to the Geological Survey in a deposit of sodium nitrate, apparently of the clay-hill type, said to lie about 5 miles south of Rawhide, Nev., and to be adjacent to a deposit of epsomite, but this deposit has not been examined by the Geological Survey.

Perhaps the most interesting feature shown by the analysis just 

given is the presence of borate in the caliche, for it suggests that 

the association of borates with nitrates in the clay-hill caliche may 

be more common than has been supposed. The caliche was tested 

for borate in the field in only one other clay-hill area, the Owl 

Spring nitrate field, but an unmistakable reaction for boron was 

obtained. (See p. 24.) The borate in the caliche there is probably 

derived from borate in the bedrock strata, because some of those 

strata gave a reaction for boron. Undoubtedly the caliche at 

places in the Furnace Creek district (pp. 86-88), where the underlying strata contain deposits of colemanite and ulexite, would be 

found to contain borates.

NITRIFICATION TESTS IN CLAY-HILL, AREAS AND IN

LEACH LAKE

Another essential step in a study of the origin of the clay-hill 

nitrate deposits is; to determine whether fixation of nitrogen from 

air in soil through the agency of bacteria is taking place in the 

vicinity of the deposits, and, if so, to what extent. With this possibility in mind the writer collected, in October, 1918, eight samples 

of different layers of ground in the nitrate deposits to be tested 

for activity in nitrification. The samples were collected in sterilized 

bottles, sealed immediately, and sent to Washington, where they 

were turned over to the Bureau of Plant Industry for testing. They 

represent material from the Saratoga, Confidence, and Zabriskie 

nitrate fields and from Leach Lake. Of these samples five represent 

soil, one caliche, one soil and caliche taken together, and one loose 

material lying in a cavity in caliche. Of the soil samples one (No. 3 

in the table) represents surface soil -the typical compact surface 

clay layer of the nitrate fields; three (Nos. 2, 4, and 8) represent 

loose saline clay soil at depths ranging from 2 to IT inches beneath 

the surface the typical " efflorescent " or " sulphate " layer overlying the caliche; and one (No. 1) represents saline clay 10 to 12 

inches below the surface of the playa, or "dry lake." A description 'of the samples is given in the following table:
94 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA 

Samples tested for nitrification

No.

1

2

3

4

5

6

7

8

Locality

Leach Lake near middle of lake. (See pp.

13-16 and pi. 3, C.)

Saratoga nitrate field,

5 feet east of 187-foot

mark near south end

of trench No. 3 in

hill No. 3. (See pi.

17, A; also Bull. 724,

pp. 43, 44, 45, pi.

11.)

3

,

Saratoga nitrate field,

5 feet west of spur

cut No. 2 in Amphitheater Canyon.

(See pi. 17; also Bull.

724, p. 47.)

... .do..... 

..... do..... ...

Confidence nitrate

field. (See pi. 16;

also Bull. 724, p. 57

(0, H), pi. 12.)

.....do.... 

Zabriskie nitrate field,

near 10-foot trench

at locality Xi. (See

p. 69, fig. 4, and pi.

12, -4.).

Material

Clay beneath surface

of dry lake. Moist,

because wet by a

rain a few weeks before sample was

taken.§

Loose powdery clay

soil containing efflorescent salts,

chiefly NasS 04 and

NaCl.

Surface soil, compact

sandy clay exhibiting usual cauliflowerlike surface and supporting no vegetation (a, pi. 17, E).

Loose powdery sandy

clay soil containing

efflorescent salts,

chiefly NasSO< and

NaCl (6, pi. 17, B).

Caliche (c, pi. 17, B)_.

Blister caliche and

clay soil overlying

it.

Loose powdery clay

mixed with much

saline material.

Loose granular flaky

clay soil. Moist,

because wet by a

rain a few weeks before sample was

taken.

Depth 

inches)

10-12

3- 9

0- 2

2-8

8-16

0-8

12-16

12-17

Remarks

Chemical analysis of a duplicate sample

showed a nitrate content of 0.29 per cent

(calculated as NaNOs) and a trace of

soluble K.

At the surface is the characteristic compact

layer of sterile clay, 3 inches thick.

Beneath it is the usual "efflorescent" or

"sulphate" layer of loose powdery clay

mixed with soluble salts, 6 inches thick.

At most places this layer gives" negative "

to "weak" reactions for nitrate. The

sample represents this layer. Beneath

it is salty caliche of the compact Saratoga

type, overlying greenish sandy clay of

Tertiary age dipping steeply. Chemical analysis of a sample of the caliche

representing a strip 17 feet long showed

3.06 per cent of sodium nitrate (see Bull.

724, pp. 19, 44, sample S-68), and analysis

of a hand-sorted sample of the same

caliche showed 11.10 per cent of sodium

nitrate. All material at this locality

dry.

Sample taken from the typical clay layer

that forms the surface in the clay-hill

nitrate areas, here 2 inches thick. At

most places this surface clay gives no

reaction for nitrate, but at some places it

gives a "weak" reaction. All material

at this locality dry.

At most places this layer gives "negative"

to ".weak" reactions for nitrate.

Chemical analysis of a duplicate sample

showed 7.06 per cent of NaNOa. Beneath the caliche lie steeply dipping

beds of gray arkosic sandstone of Tertiary age.

The blister caliche is 6 inches thick and is

overlain by 2 inches of compact sterile

clay soil. The sample represents a

vertical column of caliche and soil taken

together. Beneath the caliche are tilted

beds of greenish clay of Tertiary age

apparently consisting largely of fine

volcanic ash. The blister caliche is the

richest in nitrate .of all discovered by the

Geological Survey. (See p. 91.) All

material at this locality dry.

The material represented by this sample

lies on the floor of a cavity inside one of

the caliche blisters. (See pi. 16, B).

This material gives a very strong field

reaction for nitrate. It grades downward into steeply dipping beds of clay

that underlie the caliche and contain

very little nitrate.

The soil grades down into a horizontal bed

of loosely consolidated sandy clay of

Quaternary age, which probably contains volcanic ash. No caliche layer is

present. Chemical analysis of a duplicate sample showed 0.32 per cent of

NaNOs and a trace of soluble K. (See

pp. 69-70.)

The following report was submitted by the Bureau of Plant 

Industry:

, The eight soil samples collected from the California nitrate districts by Mr. 

L. P. Noble *.* * were tested for nitrification by adding a small measured
ORIGIN OF CLAY-HILL NITRATE DEPOSITS 95

quantity of soil to 50 cubic centimeters of nutrient solution containing ammonium sulphate. The solutions were incubated at 28° C. for two weeks. The 

nitrate nitrogen in the solutions was determined after the residue of ammonia 

from the ammonium sulphate had been boiled off. The results from the duplicate determinations were as follows:

No. 

P»of 

sample

1

2

3

4

5

6

7

8

Locality

Leach Lake. _ ______________ '. ..................................... ....

.....do.................................................................................

.....Ao...... ................. ..........................................................

Confidence nitrate field.. ________________________________

...-do............................................ ..................................

Zabriskie nitrate field. __________________ _______________

Nitrate 

found in 

solution

0.0

.0

.4

.0

.2

.1

.0

.0

Sample No. 3, the sample from the Saratoga nitrate field, appears to be the 

only, sample where nitrification was appreciable. Samples 5 and 6, although 

showing some nitrification, are in my opinion within the limits of experimental 

error. Even sample 3 is not showing rapid nitrification. It is fair to state 

therefore, that all of the samples submitted are relatively much less active 

than the usual samples of surface soil.

From this letter it appears that the one sample which represents 

soil at the surface is the only sample that shows appreciable nitrification. Accordingly the results of the tests establish a strong presumption that nitrification is relatively much less active in the soils 

of the clay-hill areas of this desert region than it is in the soils of 

moister regions. They also suggest that the nitrification takes place 

chiefly in the surface layer of the soil rather than in the underlying 

" efflorescent" layer or in the caliche, but the nitrate thus formed 

could accumulate in the caliche layer.

More samples should be collected and tested, however, before these 

results are regarded as conclusive. The samples above described 

were all collected at the end of a long hot desert summer, a season in 

which the maximum day temperatures usually reach and often exceed 

115° and in which all moisture is drawn from the soil. Perhaps 

nitrification in the soil is more active during the cooler and relatively 

moister winter. Conceivably, therefore, other samples taken in the 

spring would show more active nitrification.

ORIGIN OF CLAY-HILL NITRATE DEPOSITS

The clay-hill caliche deposits of southeastern California are not 

commercially valuable, and the quantity of nitrate in them is insignificant in comparison with that in the vast deposits of Chile. Nevertheless these deposits comprise some tracts of caliche hundreds of 

acres in extent that contain small amounts of nitrate, besides other
96 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

tracts a few acres in extent that contain between 3 and 4 per cent 

and still smaller patches that contain much more than 4 per cent. 

Samples of caliche that contain between 10 and 15 per cent have 

been analyzed. These facts are interesting to the student .of saline 

deposits, for in California, as in Chile, no satisfactory explanation 

of the origin of the nitrate has yet been found. Inasmuch as the 

nitrate in the Californian deposits may be similar in origin to that 

in the Chilean deposits, the problem of its origin is of more than 

local scientific interest. It may perhaps be solved by careful observation in the field in connection with chemical and bacteriologic 

investigation, but as the purpose of the Geological Survey's work 

during the World War was to find, in the shortest time consistent 

with systematic effort, whether workable deposits of nitrate exist in 

the region, it was neither possible nor advisable to devote time to 

this scientific research. The explorations brought out many facts 

concerning the occurrence of the nitrate, however, and afforded 

opportunity to make some tests of the numerous hypotheses hitherto 

advanced to account for the origin of the nitrate. These observations may be useful as evidence in a further study of the problem. 

Accordingly it seems worth while to discuss these hypotheses briefly, 

giving the tests recognized as applicable to the hypotheses, the evidence available, and the conclusions that seem warranted. Doubtless 

this analysis of the problem will be unsatisfactory to the reader, 

because no definite conclusion is yet possible. Probably the hypotheses enumerated cover most of the possibilities. Therefore, the 

correct explanation may lie in one of them or in a combination of 

one or more. The evidence, however, is insufficient, hence it is not 

at present possible, wholly to dismiss from consideration even those 

that are seemingly improbable, except No. 1 and perhaps No. 13. 

The object in presenting the following analysis is to clarify the problem and to indicate the lines along which further investigation may 

profitably proceed.

ANALYSIS OF THE PROBLEM

HYPOTHESES 

1. MARINE WATERS

Tests applicable. Observation; evidence of presence of marine 

waters in region in Tertiary or Quaternary time.

Evidence available. No Tertiary or Quaternary strata of marine 

origin nor any other evidence of the presence of marine waters in 

Tertiary or Quaternary time has been found in the desert region of 

southeastern California east of the Salton Sink and the extreme 

western border of the Mohave Desert. The strata that underlie the
ORIGIN OF CLAY-HILL NITRATE DEPOSITS 97

caliche areas are terrestrial deposits laid down in lakes or on the 

slopes bordering lakes.

Conclusions. This source may be dismissed from consideration 

both as a recent and as an ancient source.

2. SALINE RESIDUES OF EVAPORATED LAKES

Tests applicable. Test saline deposits of present dry lakes for 

nitrate. Test beds of rock salt in Tertiary or Quaternary strata for 

nitrate, because these salt beds represent evaporated brines of ancient 

lakes.

Evidence available. According to Gale,70 nitrate is not known to 

be present in the salt body of Searles Lake notwithstanding an 

early report concerning its presence there. Tests in the salt body 

and brine of Danby Lake yielded no reaction for nitrate. (See pp. 

59-61.) The deposit of rock salt on the floor of Death Valley covers 

an area of many square miles in the lowest part of the valley. Most 

of the surface of the salt is very rough. (See pi. 18, A.) A well 

drilled 1,100 feet below the surface of the salt went through alternating layers of salt and clay to the greatest depth reached and did 

not penetrate bedrock. Numerous tests of the surface salt have 

been made but have failed to reveal a trace of nitrate. The clay 

surfaces of some less saline playas contain nitrate, as shown by tests 

at Leach Lake. (See p. 15.) 

Every bed of roek salt in Tertiary or Quaternary strata tested 

was found to be barren of nitrate. (See pp. 59-62, 86.)

No deposit of clay-hill caliche can conceivably have been formed 

directly by the evaporation of standing water, because the caliche 

is a blanket deposit conforming to the slopes of the hills upon which 

it lies. (See fig. 1.)

Conclusions. Apparently deposits from strong brines like the deposits at Searles and Danby Lakes are a highly improbable source, 

but less saline playa clays may be a possible source, as shown by the 

presence of nitrate in the clay surface of Leach Lake, because the 

strata underlying the clay-hill areas contain many beds which represent ancient playa clays. The caliche itself is nowhere the saline 

residue of an evaporated lake or the deposit of a playa.

3. GUANO IN CAVES, CREVICES, ETC.

Tests applicable. Observation.

Evidence available. A few small accumulations of guano were 

noted in caverns in the Zabriskie area (see pp. 70-71), but none were 

noted in or near other clay-hill areas. Inasmuch as the caliche is 

a blanket deposit covering hills and hollows alike it is not conceivable that any considerable amount of nitrate from guano deposits

70 Gale, H. S., op. clt., p. 297.
98 TITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

in cavities could be washed into the soil and caliche from neighboring 

areas, even if the neighboring areas contain guano deposits, because 

many caliche-covered hills project high above the drainage channels 

that lead through them.

Conclusions. Highly improbable as a present surface source, because seemingly inadequate and because none of the larger or richer 

clay-hill caliche areas are near such deposits. Seemingly improbable as an ancient or buried source because the strata underlying the 

clay-hill caliche areas are not known to contain phosphate, a constituent of guano.

4. ACTION OF NITRIFYING BACTERIA ON ORGANIC MATTER IN SOIL

Tests applicable. Chemical determination of organic matter in 

soil samples. (Some of this organic matter may have been derived 

from underlying strata (see No. 9) and become part of the soil 

through general erosion.) Collection of soil samples in sterilized 

bottles for bacterial examination. These two determinations have 

not been made.

Evidence available. Almost total absence of vegetation is one of 

the most striking features of clay-hill caliche areas (see for example, 

pis. 4 (B, 6/), 5 (A, #), 6, 9,11,12,15 (A, #), 16, and 17), and so is 

entire absence of visible organic matter in soil.

(conclusions. Possible, although seemingly improbable because of 

absence of visible organic matter in soil.

5. FIXATION OF NITROGEN FROM THE AIR IN SOIL AND ON SURFACE OF ROOKS 

THROUGH AGENCY OF BAOTEBJA

Tests applicable. Collection of samples in sterilized bottles and 

testing for activity in nitrification. A few such samples have been 

collected and tested (see p. 94) but not enough to yield conclusive 

evidence.

Evidence available. The few samples collected and tested proved 

to be relatively much less active in nitrification than the usual samples 

of surface soil in less arid regions. (See p. 95.) This, however, 

was to be expected, because of hostile climatic conditions. Headden71 

has shown that nitrification takes place not only in the soils of arid 

regions but upon the surfaces of all kinds of rocks as well.

Conclusions. Possible, because nitrification was proved in one of 

the few samples collected and tested. Headden's results, moreover, 

make this possible source worthy of careful consideration. This 

hypothesis is attractive because it could be applied to other types of 

nitrate deposit than the clay-hill type, as, for example, the nitrate 

in Leach Lake, the Vivet Eye deposit, and the deposits on volcanic 

rocks at West Well and at San Simon, above described.

71 Headden, W. P., The fixation of nitrogen In Colorado soils: Colorado Agr. Coll. Agr. 

Bxper. Sta. Bull. 178, June, 1911; Occurrence of nitrates on rocks: Bull. 277, May, 1922.
ORIGIN OF CLAY-HILL NITRATE DEPOSITS 99 

6. FIXATION OF NITROGEN ON LEGUMINOUS PLANTS

Tests applicable. Observation.

Evidence available. Practically no vegetation of any kind grows 

upon the clay-hill caliche areas. (See No. 4.) 

Conclusions. Possible but seemingly wholly inadequate.

7. NITRATE PARTICLES IN AIR BY OXIDATION OF AMMONIA OR BY MECHANICAL ACTION OF THE WIND

Tests applicable. Collect and test dust samples after quiet and 

windy periods* Test samples of rain water. These tests have not 

been made.

Evidence available. High winds and dust storms common in the 

region.

Conclusions. Possible, but no conclusive evidence available.

8. NITRIC ACID IN RAINFALL FROM ELECTRICAL DISCHARGES DURING

THUNDERSTORMS

Tests applicable. Collect samples of rain water during thunderstorms and test.

Evidence available. Although the annual rainfall of the region 

averages probably less than 3 inches, the most violent and heavy 

rains are summer thunderstorms.

Conclusions. Possible, but no conclusive evidence available.

9. ORGANIC MATTER ENTOMBED IN STRATA AT TIME OF DEPOSITION

Tests applicable. Chemical determination of organic matter in 

samples of underlying strata selected as in test 14. This has not 

been done. Samples should be sealed to prevent access of air and 

surface bacteria.

Evidence available. Practically no traces of visible organic matter or fossils found in strata. Exceptionally some marly beds contain masses of what appear to be silicified plant stems, but these 

beds are very rare. Algal limestones occur in some but not all 

clay-hill areas.

Conclusions. This source possible but seemingly improbable because of extreme scarcity of fossils. However, it is conceivable that 

organisms that would have left no vestiges may have been entombed 

in the strata.

10. NITROGEN GASES EXPELLED DURING VOLCANIC ERUPTIONS AND CARRIED 

INTO SOIL AND ROOKS BY RAINS RESULTING FROM CONDENSATION OF 

ERUPTED WATER VAPORS

Tests applicable. Observation; proximity of clay-hill caliche deposits to areas of volcanic activity would be suggestive. Associated substances of possible volcanic origin such as boron and chlorine might be expected in the caliche. Hypothesis could be tested
100 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

negatively as follows: Near Paria, in southern Utah, are extensive 

outcrops of the Chinle formation which are covered with a clay 

soil and ground similar in appearance to that in typical clay-hill 

nitrate areas. The locality is many miles from the nearest evidence 

of volcanic activity, so that the Tertiary or Quaternary volcanic 

factor is definitely excluded there. If this ground upon examination should prove to contain clay-hill nitrate caliche the volcanic 

hypothesis could not be invoked to explain the origin of the nitrate. 

This test has not been made.

Evidence available. Tertiary or early Quaternary volcanic rocks 

lie near most if not all clay-hill caliche areas examined. The strata 

underlying most clay-hill caliche areas contain more or less volcanic 

ash evidence that intense volcanic activity prevailed in the region 

while the strata were being deposited. Chlorides are abundant, and 

some caliche contains boron. Borates occur in underlying clays at 

places.

Conclusions. Possible and entitled to careful consideration as a 

Tertiary and early Quaternary source of nitrate, because nearness 

of caliche deposits to areas of Tertiary and early Quaternary volcanic activity and association with strata containing explosive 

volcanic material may be significant. Seemingly very unlikely as a 

late Quaternary source, because the caliche is a product of later 

Quaternary time and there is no evidence of widespread volcanic 

activity in the region in the late Quaternary. It is true that recent 

cones exist in Owens Valley, at La vie and Amboy, in the Mohave 

Desert, and at the mouth of Ubehebe Wash, in North Death Valley. 

The cone figured in Plate 18, #, is the smallest of a group of five 

craters, one of which is 780 feet deep. It is probably very recent, 

because only two small gullies have been cut in the loose and easily 

eroded ash that forms the sides of the cone. The other craters are 

older, but all are late Quaternary. Ash erupted from the craters 

covers the ground for about a mile in every direction.

None of the late Quaternary volcanoes are near caliche areas, and 

the volcanic activity that they represent is utterly insignificant in 

comparison with that which prevailed in the Tertiary period.

11. NITROGEN GASES IN IGNEOUS ROCKS

Tests applicable. Collect and test for gas content samples of 

igneous rocks near caliche areas or associated with the strata underlying caliche areas. These tests have not been made. Boron-bearing 

minerals in adjacent areas or in the strata themselves might be an indicator for example, datolite, tourmaline, colemanite, ulexite.

Evidence available. Strata underlying nitrate-bearing caliche 

near Furnace Creek contain deposits of colemanite and ulexite.
ORIGIN OF CLAY-HILL NITRATE DEPOSITS 101

(See p. 87.) Strata underlying caliche in the Owl Spring field 

contain borate. (See p. 24.) Some caliche in the Owl Spring 

field reacts for borate. Blister caliche in the Confidence field contains borate. (See pp. 92-93.)

Conclusions. Possible, although very little evidence is available. 

Occurrence. of borates in underlying strata and in general region 

may be significant.

12. NITROGEN IN SPRING WATERS

Tests applicable. Collect and test spring waters for ammonium 

chloride, boron, etc. This has not been done.

Evidence, available. A number of hot springs rise in Amargosa 

Valley, and the waters of these springs are probably of deep-seated 

origin, but the springs appear to have no significant relation to the 

caliche of the clay-hill areas in the valley. Hot springs also rise 

in the Furnace Creek region. Elsewhere springs rise in or near some 

caliche areas, but at no place do they appear to have any significant 

relation to the caliche.

Conclusions. No conclusion possible, because no evidence concerning composition of spring waters is available. Might be an indirect 

source of nitrate in underground waters beneath the caliche areas, 

but in no direct sense can the clay-hill caliche deposits be considered spring deposits, because the caliche is a blanket deposit conforming to the topographic surface upon which it lies. (See fig. 1.)

13. NITRATE CONCENTRATED IN BEDS OR VEINS IN STRATA UNDERLYING THE

CLAY-HILL AREAS

Tests applicable. Observation of exposed cross sections of the 

strata and in excavations dug in the strata.

Evidence available. Beds or veins of sodium chloride, gypsum, 

celestite, colemanite, and ulexite observed in strata, but no concentrations of nitrate.

Conclusions. This source highly improbable, because after prolonged and careful search in excavations dug in the strata and in 

exposed cross sections no beds or veins of nitrate were found. At 

some places (see pp. 23, 86) the sodium chloride in the caliche is obviously derived from beds of sodium chloride in the underlying strata.

14. NITRATE DISSEMINATED IN STRATA UNDERLYING THE CLAY-HILL AREAS

Tests applicable. Obtain samples of underlying strata from 

deeper sources than any of the excavations dug in the Geological 

Survey investigations, so as to avoid influence of surface waters in 

cracks, etc., and determine soluble salts. Present analyses are inconclusive, because material was not so selected.
102 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

Evidence available. Sodium chloride and gypsum were found to 

be widely disseminated in underlying strata, particularly in clay 

beds. Nitrate was found to be present in the strata as far down as 

the Geological Survey's excavations reached, but the amounts diminish very rapidly with depth. For example, in the deepest excavation,72 3.50 per cent was found in the caliche 1 foot below the surface of the ground, 0.11 per cent in the underlying strata at a depth 

of 4 feet, and less than 0.05 per cent, or traces, at a depth of 8 feet.

Conclusions. This source of nitrate is possible, but the evidence 

available is inconclusive. In all probability the chlorides, sulphates, 

and borates associated with nitrate in the caliche are derived from 

chlorides, sulphates, and borates in the underlying strata, and it is 

this relation that suggests that the associated nitrate may be similarly derived. There would be little reason to doubt that nitrate 

disseminated in the strata is a proximate source of the nitrate in the 

caliche if sampling at depths removed from surface influences should 

reveal the presence of small amounts of nitrate in the strata.

ACCUMULATION OF CALICHE 

FIRST HYPOTHESIS

Statement.- Upward movement of soluble salts by ground water 

and subsurface moisture through capillary action.

Tests applicable. Procure if possible samples of ground water 

and test for soluble salts. Obtain samples of underlying strata 

from deeper sources than any of the excavations thus far made or 

studied so as to avoid surface influences, and test for moisture and 

soluble salts practically the same test as No. 14. Relative proportions of soluble salts in strata should agree fairly well with relative proportions of same salts in caliche. Moisture samples should 

be sealed and tested as promptly as possible. These tests have not 

been made.

Evidence available. Water table in most clay-hill caliche areas 

is apparently many feet below surface at present time. But strand 

lines across alluvial fans at levels over 600 feet above the present 

surface of Searles Lake and more obscure (and probably older) 

strand lines in Panamint and Death Valleys indicate that there 

have been one or more periods of moister climate in the region in 

late Quaternary time. During such periods the water table must 

have stood much higher than it does now. Some of the shore lines 

in Panamint and Death Valleys are shown in Plate 19, A and B. 

Those illustrated in Death Valley are cut in basalt at the north end 

of the Confidence niter hills at a point 2 miles northwest of Ashf ord

TC Noble, L. F., and others, op. cit, p. 42, pi. 8.
ORIGIN OP CLAY-HILL NITRATE DEPOSITS 103

Mill. A similar set of strand lines is cut in dissected alluvial-fan 

deposits in an embayment at Mormon Point, a few miles north of 

the locality illustrated. Those illustrated in Panamint Valley are 

also cut in old dissected alluvial-fan deposits.

Regarding subsurface moisture (as distinguished from ground 

water) in the underlying strata: All sandy beds and many clay beds 

in the clay-hill areas appear very dry, but many beds of saline clay 

and all beds of rock salt are visibly moist, even in areas where no 

rain has fallen for a year or more.

Conclusions. Although conclusive evidence from tests is not 

available, this is certainly a possible process by which the salts 

associated with nitrate in the caliche are brought into the surface 

zone, but whether nitrate is one of the salts thus brought up is not 

yet definitely known.

Climate is probably important; in moister periods the ground 

water may have been the dominant factor, leaching the salts out 

of the rocks; in more arid periods, as at present, the subsurface 

moisture is the dominant factor, bringing the salts to the surface 

zone and depositing them there through evaporation.

SECOND HYPOTHESIS

Statement. Downward movement from soil and surface, sources. 

If both this process and the preceding process are involved, this 

process would tend to mas.k the first.

Tests applicable. Observation. Follow several nitrate-bearing 

cracks downward, making 'tests at several levels in each to determine variation in nitrate content. These tests have not been made.

Evidence available. Nitrates and chlorides observed in cracks 

below caliche extend downward a foot or more into bedrock. 

Samples in excavations show rapid decrease downward in total 

nitrate content. Karst topography 73 (sink-hole drainage) in all 

the more saline clay-hill areas is striking evidence of downward 

movement of surface waters. Probably this topography was produced largely during the last moister period, because the heaviest 

rains to-day do not moisten the ground deeper than the caliche 

zone.

Conclusions. This process is certainly possible under favorable 

conditions. Climatic factor is probably important; in moister periods salts would tend to be removed through sink-hole drainage; in 

drier periods rains would penetrate only as far as caliche zone 

(as they do to-day) and leave soluble salts there upon evaporation; 

the salts deposited in this situation would be protected from being 

dissolved or washed away in surface water by the peculiarly im78 Noble, L. F., and others, op. cit., pp. 69, 70, pi. 29, A.
104 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

pervious character assumed by the compact clay layer of the top 

soil when it becomes wet. (See p. 21.)

THIRD HYPOTHESIS

Statement. Enrichment by general erosion.

Tests applicable. Observation. (1) Soluble salts should leach out 

of top soil and accumulate below surface. (2) Saline material 

should show rough zonal arrangement as effect of relative solubility 

of salts. (3) Texture of underlying strata should affect localization 

of deposits: (a) Sand and gravel should favor deep penetration of 

solutions and dissemination of salts rather than enrichment, but 

deposits might be localized at clay layers if they were near enough 

to surface; (&) clay, being impervious, should prevent deep penetration and favor localization of deposit at top of bedrock.

Evidence available. (1) The clay-hill caliche is an accumulation 

of soluble salts below the surface soil at the contact zone between 

soil and bedrock.

(2) Compact clay layer of top soil at surface contains little soluble 

material; underlying efflorescent layer, more; caliche, most. (See 

pp. 2, 42, also fig. 1 and pi. 9, 0.) Saline material in these layers 

shows rough zonal arrangement in order of relative solubility sulphates chiefly in efflorescent layer; chlorides and nitrates chiefly in 

underlying caliche. The conformity of zoned salts to topography is 

striking in most of the clay-hill areas and indicates close relationship 

between arrangement of deposits and processes of general erosion.

(3) (a) In general, sandstone areas are notably barren of caliche. 

The chief exception is the Amphitheater Canyon caliche (see pi. 17, 

A, /?), overlying sandstone in the Saratoga field,74 but even here 

thin partings of clay occur in the sandstone, and the sandstone itself 

contains clay, (b) Practically all caliche deposits overlie clay 

strata. All are localized at top of bedrock.

The reasons for certain sharp variations in nitrate content of 

caliche 75 which coincide with variations in the character of the 

underlying strata (for example, sharp localization of rich blister 

caliche in Confidence field on green clay (see pi. 16, A), and certain 

variations on other kinds of strata in the Saratoga field) have not 

been studied enough to be understood, but it is possible that rock texture is the determining factor.

Conclusions. This appears to be the dominant process involved.

CONCLUSIONS REGARDING ORIGIN

 There are many possible primary sources of the nitrate and many 

possible combinations. Which source or combination of sources is the 

true one is not known, because sufficient evidence is not yet available.

74 Noble, L. F., and others, op. cit, p. 38. TC Idem, pp. 19, 20.
FINAL COMMENT 105

Three processes are probably involved in the accumulation of the 

caliche. Enrichment by general erosion (third hypothesis) is probably the dominant process, subject to at least two controls 

the quantity of saline material available and favorable climatic 

conditions.

Two factors must obviously enter into every hypothesis concerning 

the source of the nitrate and into every explanation .of the mode of 

accumulation of the caliche. They are arid climate and time.

DEPOSITS OF OTHER MINERALS IN TERTIARY CLAYS

The widely distributed and very similar sets of Tertiary beds in 

the desert region, with whose outcrops most of the clay-hill nitrate 

deposits are associated, are apparently more worth prospecting for. 

other nonmetalliferous materials than for nitrate. At one place or 

another workable deposits representing a variety of useful commodities have been found in them. An incomplete list includes 

volcanic ash, bentonite, different kinds of useful clay, colemanite 

and other boron minerals, strontium minerals (strontianite and celestite), rock salt, gypsum, and magnesite.

The deposits of bentonite at Shoshone and Ash Meadows, in the 

Amargosa region, are in Quaternary beds forming a part of the 

Zabriskie nitrate field, but bentonite has been found also in Tertiary 

beds in the Upper Canyon nitrate field.

A deposit of kernite, commercially known as rasorite (Na.,O. 

2B203 .4H2 0), recently discovered by the Pacific Coast Bora.x Co. 

near Kramer, Calif., occurs in some of these Tertiary beds. (See pi. 

1.) This deposit is probably the richest borate deposit known.

A deposit of epsomite, or " epsom salt" (MgSO4 .7H2O), near 

Wingate Pass is associated with Tertiary beds similar in character 

and origin to those in the borate and nitrate districts. (See pi. 1.) 

A monorail tramway over 30 miles long has been built to the deposit 

from a point near Searles Lake, on the Trona Railroad. Whether 

the epsomite occurs as a blanket or surface deposit corresponding 

either to the efflorescent soil layer or to the caliche layer of the clayhill nitrate deposits, or as a bed or beds in the Tertiary strata, is not 

known. The ground on the outcrops of the Tertiary strata in this 

area is exactly like that in the typical clay-hill nitrate tracts and if 

tested would probably reveal the presence of niter-bearing caliche.

FINAL COMMENT

" Notwithstanding the adverse conclusions regarding the commercial 

possibilities of all the nitrate deposits so far examined in the desert 

region the writer does not wish to be understood as discouraging 

further prospecting for nitrate there. It is conceivable that some-
106 NITRATE DEPOSITS IN SOUTHEASTERN CALIFORNIA

where in the region deposits of caliche richer than those examined 

may exist. Moreover, nitrate may occur in some form not now 

known, for the recent discovery of the rich deposit of kernite, a 

boron mineral whose very existence in mineralogy was unknown 

before the discovery, shows that the desert rocks still contain unknown possibilities. He wishes to point out emphatically, however, 

that in view of the failure of the actual results of the Geological 

Survey's investigation even remotely to fulfill the expectations that 

might reasonably be based on the many glowing reports concerning 

the known deposits, no one should undertake commercial development of any of the deposits without a full understanding of the 

complex chemical problems involved, the superficial character of the 

deposits, and the highly speculative nature of the financial risk that 

it would be necessary to incur.

Nor does the writer wish to discourage deep drilling in the strata 

underlying the clay-hill nitrate deposits, provided the enterprise is 

undertaken primarily for scientific purposes and with a full realiza- 

.tion of its extremely speculative character as regards the finding of 

commercially workable beds or concentrations of nitrate in the strata, 

for the results might throw considerable light upon the problem 

of the origin of the nitrate. It is not yet known whether small 

amounts of nitrate are contained in the strata at depth, although 

the results of the Geological Survey's investigation are practically 

conclusive that such strata contain no commercially workable beds 

or concentrations of nitrate. The writer suggests that persons who 

may have occasion in the future to drill deep holes in the strata 

underlying the clay-hill areas in search of water or mineral deposits 

other than nitrate preserve carefully the cores taken out and test 

them for nitrate. A record thus obtained in connection with exploration for other mineral deposits would afford a cheap and feasible 

means of testing the strata for nitrate and of obtaining information 

that might be of considerable scientific interest in the study of the 

origin of the clay-hill nitrate.
INDEX

Amargosa region, conclusions as to value of

nitrate deposits in____.__ 2-3 

partial analyses of caliche from nitrate

fields of ....................... 88-91

Amargosa Valley, recent alluvium in.. ___ 67 

Amphitheater Canyon, nitrate ground in_. pi. 17 

Animas Valley, N. Mex., nitrate claims in.. 80-85

Bailey, 0. E., quoted......... ...... 10,19-20,33

Bailey, R. K., analyses by................... 75

Barstow synclino, nitrate deposits in.... .. 5-8

Beal tract, reconnaissance of...___._ 55 

Bentonite, occurrence of__________. 105 

Boron, tests for, in Owl Spring nitrate field.. 21,24 

Bureau of Plant Industry, report by,' on

results of nitrification tests_ 94-95

Caliche, accumulation of, hypotheses for... 102-104 

Chemehuevi Wash, views of ..____.. pis. 6,7 

Clay-hill nitrate deposits, origin of...... 95-105

Colorado River Valley, occurrence of nitrate

in...____.__.________ 32-33 

plan and results of investigations in.... 36-38

previous exploration for nitrate in._ 33-36 

reason for investigation of areas in....... 35-36

Confidence nitrate field, blister caliche from,

analyses of...... .............. 91-93

blister caliche from, composition of

soluble salts in................... 92

nitrification tests of samples from___.. 94,95

views in___..____..__... pi. 16

Coolgardie Lakes; nitrate deposits in...__ 8-9

view of_________....__-...--- pi. 2

Danby Lake, conclusions regarding_____ 61-62 

exploration of,__..... .._--..- 59-61 

location and geologic features of _.. 57-69 

reason for examination of. 57 

views of._______..._____... pi. 10

Death Valley, cinder cone in ...... pi. 18

salt deposit in. _____.____ . pi. 18 

strand lines in_____ .. ....' pi. 19

Eberenz-Beach nitrate claims, analyses of

samples of surface deposits from. 75 

beds of tuff on, nitrate in.. .. 77-78 

conclusions regarding nitrate deposits on. 78-80 

examination of._.... .......... 73-78

geology of.____._ .._..-. 72 

location of____________.____ - 71-72 

supposed mode of occurrence of nitrate on. 73 

surface deposits of nitrate on____.... 74-77

views of..........___....... . pis. 13,16

work done on__ ____ ______ 73

Exploration of the region, possible results

from future__________ 105-106

3201 31 8

Page

Fish Lake Valley, Nev., tests for nitrate in.. 88 

Furnace Creek, Tertiary strata south of..... pi. 16 

Furnace Creek Valley, Calif., tests for nitrate

Eungerford-Moore nitrate 'claims, conclusions regarding,..________ 86-86 

examination of. .__.._____._ 82-85 

geology of...._,____________ 81-82

location and accessibility of........__ 80-81

views of.___.__...____.___ pi. 14

Kernite, occurrence of.__________ 105 

Knopf, Adolph, quoted.... ________ 5-6

Leach Lake, conclusions regarding nitrate in. 15-lft 

exploration in....___.________ 14-15 

general features of..... _______ 13-14 

tests of samples from..._______ 15,94-95 

view of.._______________ pi. 3.

Leach Point Valley, nitrate deposit in.___ 9-10

Map showing position of nitrate fields.___ pi. 1

Melhaso, John, quoted__._______ 67

Mesquite Trough, view across______-.. pi. 4

Muddy Creek valley, Nev., tests for nitrate in. 86

Mud Hill, tests of samples from.. 31

views of...._....__ __ .. . pi. 4

Nitrate deposits, conclusions regarding origin

of............................. 104-105

explorations for, during World War__ 1 

methods of.... ... 3-4

general character of.____..____... 2 

list of areas examined for..___... .. 5. 

Nitrification tests in clay-hill areas and in

Leach Lake......______... 93-96.

Origin of clay-hill nitrate deposits, hypothesis for....__.................. 96-102

Owl Spring nitrate field, conclusions regarding..... ...............:... 24-25

exploration in_ _ __.._ .. 20-24 

location and geology of...______... 16-19 

previous work in...... _ __.... 19-20 .

view in....-AS.*--,,------.-.-----.----.- pi. 3

^WEf/F.Fn Panamint Valley, strand lines-fB-Jju'XJc__ pi. 19

Pilot Knob, view and diagrammatic section of. pi. 2

Pilot nitrate field, conclusions regarding. 13

exploration in....... 11-13

location and extent of.....__.... - 10

previous work in. __ _ 10-11 

view of west end of._..__.._ . pi. 3

Rasorite. See Kernite.

107
108 INDEX

Page

Ratliff nitrate claims, conclusions regarding- 70 

exploration of__________--___ 68-70 

general features of...__.. . 67-68 

geology of........_....-......-.-..-... 64-67

location of___._.__...... . 62

reason for investigation of.___.___ 62 

results of tests for nitrate on........ .. 69-70

views of____.. __________ pis. 11,12 

Riverside Peak, gypsite deposit on...._ pis. 8,9

San Simon, Ariz., nitrate claims northeast of 7i-80 

Saratoga nitrate field, nitrification tests of

samplesfrom.._________ 94,95

view in Amphitheater Canyon in __ pi. 17 

Shoshone, Calif., nitrate deposits near___ 62-71

tests for nitrate in bed of volcanic ash near. 71 

Strontium Hills, geologic features of..___ 5-6

Tertiary strata, random tests for nitrate in_ 85-88 

Topock tract. See Beal tractTurner, H. W., quoted...................... 34

Twenty-nine Palms Springs area, conclusions

regarding nitrate near....___ 32

exploration of __................ 29-32

geology of..._ __ . .. 27-29 

location and topographic features of. .. 25-27 

reason for investigation of _ . .. 25 

view of _________________ pi. 7

Page 

Vidal tract, exploration in...---^.-:. ..... 55-57

tests of samples of nitrate from_____ 56 

Virgin River Valley, Nev., tests for nitrate in. 86 

Vivet Eye tract, conclusions regarding nitrate

deposits in....._._ .... 54-55

exploration in____ ______.__ 52-54 

location and geology of...............__ 49-52

nitrate determinations on samples from.. 53,54

West Well tract, areas containing nitrate in . 39 

clay-hill deposits in.....,...--........._ 39-47

exploration of._____________ 43-47 

geology of..--...-.---.-....-....--..-... 38-42

location and extent of....__...___ 38

mode of occurrence of nitrate in_ ___ 42-43 

nitrate deposits associated with volcanic

rocks in......................_ 47-49

results of sampling in pit 2in ______ 47 

section of formations exposed in_. ___ 42 

views of..____ .__.... __ pi. 5

Zabriskie nitrate field, geologic section of__ 64-65 

lake beds in..__________-.___ 65-97 

nitrification test of sample from...___ 94,95

Zabriskie nitrate field. See also Ratlifl 

nitrate claims.

o