Geologic Investigations 

in the Mojave Desert 

and Adjacent Region 

California

GEOLOGICAL SURVEY BULLETIN 1045

This bulletin was printed 

as separate chapters, A-F

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : I960
UNITED STATES DEPARTMENT OF THE INTERIOR 

FRED A. SEATON, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

The U.S. Geological Survey Library has cataloged this publication as follows:

U.S. Geological /Survey.

Geologic investigations in the Mojave Desert and adjacent, 

region, California. Washington, U.S. Govt. Print. Off., I960...

iv, 393 p. maps, diagrs. 24cm. (U.S. Geological Survey. Bulletin 

1045)

Part of illustrative matter in pocket.

This bulletin was printed as separate chapters A-F.

Bibliographies included.

1. Geology California Mojave Desert. 2. Borings California ... 

Mojave Desert. 3. Mojave Desert, California. (Series)
CONTENTS

[The letters in parentheses preceding the titles designate separately published chapters]

Page

(A) Core logs from Owens, China, Searles, and Panamint basins, California, by George I. Smith and Walden P. Pratt.__._.________._ 1

(B) Core logs from two test holes near Kramer, San Bernardino County,

California, by D. D. Dickey.___ .__-----._______ ._ ._ ._.__. 63

(C) Core logs from Soda Lake, San Bernardino County, California, by

Siegfried Muessig, George N. White, and Frank M. Byers, Jr_____ 81

(D) Core logs from Bristol, Cadiz, and Danby Dry Lakes, San Bernardino

County, California, by A. M. Bassett, D. H. Kupfer, and F. C.

Barstow___ ,_._._._.____.___..-_--_-_____ .__._._ .... 97 

(E) Core logs from Searles Lake, San Bernardino County, California, by

David V. Haines. .__._._______________________ 139

(F) Core logs from five test holes near Kramer, California, by William K.

Benda, R. C. Erd, and Ward C. Smith__.._______..........._ 319

ILLUSTKATIONS

[Plates 1-8,11,12 in pocket]

PLATE 1. Graphic logs of cores from Owens, China, Searles, and Panamint 

basins.

2. Graphic logs of cores from Four Corners test holes 1 and 2 

near Kramer.

3. Graphic logs of cores from Soda Lake.

4. Graphic logs of cores from Bristol, Cadiz, and Danby Dry 

Lakes.

5. Isopach map of upper salt body.

6. Isopach map of lower salt body.

7. Graphic logs of cores from drill holes GS-1 to GS-18.

8. Graphic logs of cores from drill holes GS-19 to GS-41.

m
IV CONTENTS

Page 

PLATE 9. Core from hole GS-26__________________-.Facing 150

10. Core from hole GS-21____________________Facing 151

11. Geologic map and sections for Kramer-Four Corners area showing gravimetric data.

12. Graphic logs of the cores from Four Corners test holes 1 to 5

near Kramer. 

FIGUEB 1. Map showing the location of Owens, China, Searles, and

Panamint basins and the location of the holes drilled- ______ 2

2. Diagrammatic profile of Pleistocene lakes in Owens, China, 

Searles, and Panamint basins showing the elevation of 

spillways--_________-_-____-._.-._..._-»-___-__-_-.___ 3

3. Index map showing location of Four Corners test holes 1 and 2__ 64

4. Index map showing the location of Soda Lake and of the core

holes drilled---_____________ ___._._._..__ 82

5. Index map showing the location of Bristol, Cadiz, and Danby

Dry Lakes and of the holes drilled_______________._._ 98

6. Index map of Searles Lake_____________________________ 141

7. Generalized graphic core log of mineral data from holes GS-14,

GS-15, and GS-16_______________.__._._._.___._._____ 145

8. Index map showing location of five drill holes near Kramer,

in the Mojave Desert._________________________________ 321

U.S. GOVERNMENT PRINTING OFFICE: I960
Core Logs From Owens 

China, Searles, and 

Panamint Basins 

California

By GEORGE I. SMITH and WALDEN P. PRATT

GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT AND ADJACENT REGION

CALIFORNIA

GEOLOGICAL SURVEY BULLETIN 1045-A

Detailed logs of drill cores of 

Quaternary lake sediments

UNITED" STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1957
UNITED STATES DEPARTMENT OF THE INTERIOR 

Fred A. Seaton, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U. S. Government Printing Office 

Washington 25, D. C. - Price 55 cents (paper cover)
CONTENTS

Page

Abstract--------------------------------------------------------------------- 1

Introduction---------------------------------------------------------------------------------------------------------------------------------------------- 1

Logging methods-------------------------------------------------------------------------------- 3

Logs of cores from Owens, China, Searles,

and Panamint basins -----------.---.-.........-----------...-.....-.---.....- 5

Owens drill hole 1......................................................................................................... 5

China drill hole MD-1------.-.-.--.---.-------------.-.-.---..-- 14

Searles drill hole L-W, L-W-D . -- ............ ...... . 25

Panamint drill hole 1, la---------------------------------- 51

Panamint drill hole 2 ............................................................................................................. 54

Panamint drill hole 3 ,.......- .... . . .......... ............................... 57

ILLUSTRATIONS

Plate 1. Graphic logs of cores from Owens, China, Searles,

and Panamint basins -- -- ... .. ...... in pocket

Figure 1. Map showing the location of Owens, China, Searles, *8e 

and Panamint basins and the location of the 

holes drilled---------------------------------- - .. 2

2. Diagrammatic profile of Pleistocene lakes in Owens, 

China, Searles, and Panamint basins showing the 

elevation of the spillways.--.---- . 3

m

GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT 

AND ADJACENT REGION, CALIFORNIA

CORE LOGS FROM OWENS, CHINA, SEARLES, AND 

PANAMINT BASINS, CALIFORNIA

Bv GEORGE I. SMITH and WALDEN P. PRATT

ABSTRACT

Detailed logs of drill cores are presented in this report. The drill cores 

are of sediments from four basins that were occupied during the Pleistocene 

by a continuous chain of lakes. Owens Lake basin (one hole, 920 feet) contains 

fine-grained sediments and includes locally many diatoms and ostracodes. 

China Lake basin (one hole, 700 feet) contains silt- to sand-sized clastic sediments and some calcite and gaylussite; a few diatoms, ostracodes, and mollusks 

are present. Searles Lake basin (one hole, 875 feet) contains many layers of 

gaylussite- or pirssonite-bearing sediments intercalated with beds of halite, 

trona, and lesser amounts of other minerals peculiar to Searles Lake; the top 

120 feet consistsof thicker evaporite bodies with a more complex mineralogy. 

Panamint basin (three holes, 500, 375, and 995 feet) contains clastic deposits 

ranging from clay to gravel, a small amount of gypsum, anhydrite, a trace of 

bassanite, and thick bodies of halite in the basin center; a few diatoms and 

ostracodes are present.

INTRODUCTION

In 1952 the U. S. Geological Survey began an investigation of 

saline deposits in the Mojave Desert and adjacent parts of southeastern California. As a part of this investigation, core holes 

were drilled in several playas to obtain geologic information. 

Among the playas~drilled were Owens Lake, China Lake, Searles 

Lake, and the two playas in Panamint Valley (fig. 1). The five 

playas are considered as a group because they occupy basins that 

probably contained a continuous chain of lakes during the pluvial 

periods of the Pleistocene.

The relations between the basins are shown diagrammatic ally 

in figure 2 and may be summarized as follows: 1 The principal 

source of water was drainage from the eastern slopes of the 

Sierra Nevada; this water fed the Owens River and flowed into 

Owens Lake. When the lake filled to a level about 200 feet above 

the present playa surface, its waters overflowed through a narrow 

gorge that led into Indian Wells Valley and formed China Lake. 

This broad, shallow lake spilled over a low divide into Searles 

basin and filled it to a maximum depth of about 640 feet; during 

high-water periods the divide was submerged and China Lake
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

FIGURE i.-Map showing the location of Owens, China, Searles, and Panamint basins

and the location of the holes drilled.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS *

became simply a shallow arm of Searles Lake. From Searles 

Lake the water flowed around the south end of the Slate Range into 

Panamint Valley and rose to about 930 feet above the present 

playa; the water then spilled over Wingate Pass into Death Valley.

At the time of Gale's investigation, very little was known about 

the fill in these basins; a few holes had been drilled in Searles 

Lake, but no subsurface data were available for Owens, China, 

and Panamint Lakes. Since that time a wealth of information has 

been accumulated about the fill in Searles Lake and, to a lesser 

extent, the others.

In 1952 the writers began a study of the accumulated data and 

in 1953 the cores described in this report were obtained. Although 

the overall study is still far from completion the written and 

graphic logs (pi. 1) are being presented now so that the data will 

be available to others.

LOGGING METHODS

All cores were logged in the field, using a hand lens and 

binocular microscope, a few hours after they were removed from 

the holes. They were relogged in the laboratory using a petrographic microscope for the more difficult mineral identifications 

and a binocular microscope and hand lens for the remainder; the 

relogging allowed a uniformity of detail and technique that will 

facilitate interpretation.

The cores from Owens and China Lakes were logged in the 

field by Pratt, and relogged in the laboratory by Pratt and Smith. 

At Searles Lake, Searles L-W-Dwas logged in the field and in the 

laboratory by Pratt and Smith. Searles L-W (the top 150 feet of 

L-W-D) was drilled by the American Potash & Chemical Corp. 

in 1950; they have generously allowed the log, made by F. J. 

Dluzak and M. Flaherty and modified by Smith, to be included in 

this report. The cores from Panamint Valley were logged in the 

f ield by Frederick C. Bar stow, Roland E. von Huene, and Smith; 

the laboratory logs by Smith and Ross C. Ellis utilized much 

material from the field logs.

The writers are grateful to Robert D. Alien for numerous 

mineral identifications made with immersion oils; minerals so 

identified are denoted in the logs by an asterisk (*).

After Gele, 1914

FIGURE 2. Diagrammatic profile of Pleistocene Lakes in Owens, China, Searles, and 

Panamint basins showing the elevation of the spillways.
4 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

In compiling the final logs the following conventions were established for the sake of uniformity.

Recovery.-Where the core from any given run2 was less than 

100 percent, there was generally no reliable indication of the 

position of the recovered core within the run. For the Panamint 

Valley logs, which were made first, the log of a recovered core 

was "expanded" to fill the entire run; each unit within the run was 

expanded proportionally. The cores recovered from the drill 

holes at Owens, China, and Searles Lakes were arbitarily assigned to the upper end of the run and the missing portion to the lower.

Caving.-Between drilling periods there was commonly some 

caving of material from the walls higher in the hole, and the caved 

materials were unavoidably recovered in the core barrel along 

with the core. They were saved and are included in the log but 

have been designated as slump wherever the combination of poor 

compaction, position at the top of the run, and anomalous lithology 

have suggested such an origin. Some other parts of the core were 

probably also formed in this way, but they have not been designated 

as such because the evidence was inconclusive.

Sediment names. Sediment names are in accord with those 

suggested by Wentworth. 3 Unless otherwise noted, sand is poorly 

sorted and the fragments are angular to subangular.

Colors. -Colors have been named and numbered according to 

the Rock-color Chart distributed by the Geological Society of 

America. 4

Fossils. -The estimated abundance of diatoms or ostracodes 

in the Owens and China cores is indicated in a very general way 

by the following relative terms:

"noted" ! or 2 lossils seen throughout entire unit, 

"sparse" 3 to 10 fossils seen throughout entire unit, 

"common"-from "sparse" to about 10 fossils per square inch, 

"abundant"-from about 10 fossils per square inch to very "abundant." 

"very abundant" fossils appear to form more than 50 percent of the core.

1 Gale, H. S., 1914, Salines in the Owens, Searles, and Panamint basins, southeastern 

California: U. S. Geol. Survey Bull. 580-L, p. 251-323.

2 The term "run" refers to the length of hole drilled between removals of the core 

barrel frqm the hole. Usually a run was 10 feet.

3 Wentworth, C. K., 1922, A scale of grade and class terms for clastic sediments: 

Jour. Geology, v. 30, p. 377-392.

4Goddard, E. N., (chm.) and others, 1948, Rock-color chart: Washington, D. C., Natl. 

Research Council (republished by Geol. Soc. America, 1951).
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS °

LOGS OF CORES FROM OWENS, CHINA, SEARLES, AND 

PANAMINT BASINS

OWENS DRILL HOLE 1

__ ___________[Sixty-six percent of core recovered]_______________________

Unit

/*IN thickness Description 

(feet) (feet)__________________________________________

3.0 3.0 No core. This section, exposed in a pit about 10 ft 

from the hole, consists of irregular crusts of sandy 

trona grading down into horizontally banded crusts 

about \ in. thick separated by vugs up to an inch thick. 

5.1 2.1 Gaylussite*, and alittle clay. Crystal sizes up to 2 mm, 

average about | mm. Yellowish gray (5Y8/1), massive. Poorly consolidated. 

8.0 2.9 No core.

45.0 37.0 No core. Drilling characteristics indicated that this 

section was poorly compacted clay. The few cuttings 

recovered show the upper part to consist of clay containing up to about 10 percent concretions(?), averaging about 1 mm across, dark yellowish orange 

(10YR6/6), composition unknown; this clay grades 

down into clay which is more compacted and contains 

fewer concretions. Clay is pale greenish yellow 

(10Y7/2) with streaks of pale yellowish orange 

(10YR7/5). Apparently massive.

53.4 8.4 Clay, light greenish-gray (5GY7/1), massive. Ostracodes common; diatoms noted. 

55.0 1.6 No core.

64.4 9.4 Clay, yellowish-gray (5Y8/1) to lighi greenish-gray 

(5GY8/1), massive. Ostracodes sparse in middle of 

this unit.

65.0 .6 No core.

71.3 6.3 Clay, yellowish-gray (5Y8/1), massive. Diatoms abundant to very abundant. 

75.0 3.7 No core. 

85.0 10.0 Clay, yellowish-gray (5Y8/1), massive. Diatoms very

abundant; single fish scale noted at 84.6 ft.

90.6 5.6 Clay, similar to unit above. Diatoms very abundant. 

93.4 2'.8 Clay, yellowish-gray (5Y7-8/1), massive. Diatoms

common; ostracodes sparse. 

95.0 1.6 No core. 

102.5 7.5 Clay, similar to clay at depth of 85.0 ft. Diatoms very

abundant.

105.0 2.5 No core. 

115.0 10.0 Clay, similar to clay at depth of 85.0 ft. Diatoms very

abundant.

121.3 6.3 Clay, yellowish-gray(5Y8/1); generally massive, laminar banding noted at 117.8. Diatoms very abundant 

in upper part; diatoms sparse, ostracodes abundant 

in lower part; gradational zone in middle. 

125.0 3.7 No core. 

126.7 1.7 Clay, yellowish-gray (5Y7/1), massive. Ostracodes

abundant.

127.7 1.0 Clay with laminar beds of silt, yellowish-gray (5Y6/2); 

contains small rounded particles that may be concretions. Ostracodes locally abundant. 

130.0 . 2.3 No core.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

OWENS DRILL HOLE 1-Continued

Depth Unit

(feet) thickness Description 

_________(feet) ______________________________________

130.8 0.8 Clay with laminar beds of silt, similar to material at 

depth of 127.7ft.

134.5 3.7 Clay, yellowish-gray (5Y8/1) to light greenish-gray 

(5GY8/1), massive. Ostracodes common in upper 

part grading to abundant in lower, part.

140.0 5.5 No core.

144.9 4.9 Clay, pale greenish-yellow (8Y7/2); generally massive, 

local thin beds of silt. Top foot poorly consolidated. 

Ostracodes common to abundant.

148.2 3.3 Clay, yellowish-gray (5Y8/2), massive. Diatoms very 

abundant. Top 5 in. represents a transition from 

the unit above and contains both ostracodes and 

diatoms.

150.0 1.8 No core.

159.7 9.7 Clay, yellowish-gray (5Y8/2), massive. Grades into 

unit below. Diatoms very abundant.

160.0 .3 Clay, yellowish-gray (5Y8/2), massive. Ostracodes 

and diatoms common.

165.8 5.8 Clay, pale greenish-yellow (10Y7/2); generally massive, thin-bedded at base. Ostracodes and diatoms 

abundant.

166.8 1.0 Clay, pale greenish-yellow (10Y8/2), massive. Diatoms very abundant in upper part.

169.0 2.2 Clay, pale greenish-yellow (10Y7/2); generally massive, faint laminar bedding in middle part. Ostracodes 

abundant except in a 2-in. zone at 167.5 ft.

170.0 1.0 No core.

180.0 10.0 Clay, yellowish-gray (5Y6/2) to pale-olive (lOYe/2)^ 

massive. Ostracodes abundant, locally sparse; diatoms common at base.

184.9 4.9 Clay, a 2-in. silty zone at 181.5 ft; yellowish gray 

(5Y6/2) to pale olive (10Y6/2); massive. Ostracodes 

abundant; diatoms common in top foot.

190.0 5.1 No core.

193.5 3.5 Clay, yellowish-gray (5Y6/2), massive. Core still 

damp. Diatoms range from sparse to abundant.

198.8 5.3 Clay, yellowish-gray (5Y7/2) to pale greenish-yellow 

(10Y8/2), -massive. Diatoms common to abundant; 

ostracodes locally sparse.

200.0 1.2 No core.

202.2 2.2 Clay, yellowish-gray (5Y7/2), massive. Diatoms very

abundant.

205.0 2.8 No core.

211.5 6.5 Clay, yellowish-gray (5Y7/2), massive, in top i^ ft 

diatoms sparse to abundant, ostracodes common; in

remainder of unit diatoms generally abundant, common in middle part.

215.0 3.5 No core.

215.6 .6 ciay, light olive-gray (5Y5/2) and yellowish-gray 

(5Y8/2); laminar bedding, Ostracodes and diatoms

common, .

218.4 2.8 Clay, yellowish-gray (577-8/2), maSSlVS.

very abundant. 

220.0 1.6 No core. 

221.4 1.4 Clay, yellowish-gray (5Y7/2), massive. Diatoms very

abundant.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

OWENS DRILL HOLE 1-Continued

Depth Unit

(feet) thickness Description 

(feet)______________ ___

225.6 4.2 Clay, yellowish-gray (5Y6-7/2); generally massive, 

local thin to laminar bedding. In upper third diatoms 

very abundant, ostracodes sparse; in lower twothirds diatoms and ostracodes common to abundant.

230.0 4.4 No core.

234.3 4.3 Clay, thin beds of silt in lower part; bedding thin to 

laminar, locally massive; yellowish gray (5Y7/2-3), 

local partings of light yellowish gray (5Y8/2). Ostracodes common, locally abundant; diatoms abundant at 

232.0ft.

238. 3 4.0 Clay with thin to laminar beds of silt, yellowish-gray 

(5Y7/2) to dusky yellowish-gray (5Y6/3). Ostracodes 

locally sparse.

240.0 1.7 No core.

248.4 8.4 Clay, similar to clay at depth of 238.3 ft. Ostracodes

locally common. 

250.0 1.6 No core. 

253.6 3.6 Clay; generally massive, local laminar bedding; yellow

ish gray (5Y6/2) to pale greenish yellow (10Y7/2).

Ostracodes sparse.

255.6 2.0 Clay, yellowish-gray (5Y7/2) with streaks of grayishorange (10YR6/4), massive. Diatoms very abundant,

ostracodes sparse. 

260.0 4.4 No core. 

264.4 4.4 Clay, yellowish-gray(5Y7/2)with streaks of grayish-orange

(10YR6/4), massive. Diatoms common to abundant,

locally very abundant. 

270.0 5.6 No core. 

290.0 20.0 No core. This section drilled as if very soft.

300.0 10.0 No core. Cuttings include a 1-in. angular fragment of 

dark limestone*. Section drilled similarly to unit 

above.

302.0 2.0 Clay, grayish-olive (10Y4/2). Core still damp, massive. Diatoms common.

310.0 8.0 Clay, light greenish-gray(5GY7/1), massive. Diatoms 

sparse to common.

320.0 10.0 No core.

330.0 10.0 Clay, light greenish-gray(5GY7/1), massive. Diatoms 

common to abundant.

336.2 6.2 Clay, similar to unit above.

339.2 3.0 Clay; mottled coloring includes yellowish gray 

(5Y7/2-3) and streaks of dark yellowish orange 

(10YR6/6); massive. Diatoms common, locally 

abundant.

340.0 .8 No core.

345.6 5.6 Clay, yellowish-gray (5Y7/1), massive. Diatoms 

sparse to common.

347.8 2.2 Clay, yellowish-gray (5Y7/1-2), massive. Diatoms 

common.

350.0 2.2 No core.

358. 2 8.2 Clay, yellowish-gray (5Y7/2); most of unit damp, somewhat darker; massive. Diatoms sparse, locally 

common. Poorly consolidated.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

OWENS DRILL HOLE 1 Continued

Unit 

thickness Description

(feet)

358.6 0.4 Clay with very fine sand. Sand fragments are about 

two-thirds quartz and feldspar and one-third hematite* and limonite*. Colors mottled, include light 

olive gray (5Y5/2) and moderate brown (5YR3/4), 

Massive. Diatoms sparse. Core still damp.

359. 1 . 5 Clay; colors similar to those found at depth of 339. 2 ft; 

massive. Diatoms common to abundant.

360.0 .9 No core.

361.0 1.0 Clay, light olive- gray (5Y4/2), massive. Diatoms 

common to abundant. Core still damp.

363. 3 2. 3 Clay, slightly silty in lower part; light greenish gray 

(5GY7/l)topale greenish yellow (10Y7/2); massive, 

local faint banding. Ostracodes common to abundant. 

Grades into unit below.

370.0 6.7 Clay, locally silty, especially in bottom 1.6 ft; colors 

similar to unit above; generally massive, some thin 

to laminar beds of silt. Ostracodes sparse to common. Lower part of core still damp.

372.8 2.8 Clay, dark greenish-gray (5GY 4/1), massive. Diatoms 

sparse in upper part. Core still damp.

378.4 5.6 Clay, light olive-gray (5Y4- 5/2) to pale-olive (10Y5/2); 

thin to laminar bedding caused by silt partings , locally 

massive. Ostracodes sparse to common, locally 

abundant; diatoms noted at base.

380.0 1.6 No core.

382.1 2.1 Clay, grayish-olive (10Y4/2), massive. Diatoms 

sparse. Core still damp.

388.0 5.9 Clay with interbedded silt, yellowish-gray (5Y6/2) and 

pale greenish-yellow (10Y7/2). Ostracodes common 

to abundant; diatoms sparse at base.

390.0 2.0 Clay, locally slightly silty, pale greenish -yellow 

(10Y7/2), massive. Ostracodes and diatoms sparse.

391.6 1.6 Clay, grayish-olive (10Y4/2), massive. Core still 

damp.

399.5 7.9 Clay, pale greenish- yellow (10Y8/2) to yellowish-gray 

(5Y7-8/3), massive. Diatoms common to abundant.

400.0 .5 No core.

401.7 1.7 Clay, grayish-olive (10Y4/2), massive. Core still 

damp. Poorly consolidated.

407.8 6.1 Clay, yellowish- gray (5Y7/2) to light greenish-gray 

(5GY7/1); generally massive, silty partings in top 

foot. Ostracodes and diatoms locally sparse. At the 

top of this unit is a 2- in. thick core of greenish-gray 

(5GY5/1) limestone; it is not known if this represents 

a bed of limestone or a large rock fragment that was 

cored by the drill.

410.0 2.2 No core.

415.0 5.0 Clay With lOCal thin beds of silty clay and silt, yellowishgray (5Y7/2) to pale-olive (10YS/2); generally thinbedded, locally massive. Ostracodes sparse to common, locally abundant.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

OWENS DRILL HOLE 1-Continued

Depth Unit

r£0+ \ thickness Description Vieei;; (feet)

420.0 5.0 Clay, yellowish-gray (5Y7/2), massive. At 418.6 ft is 

a 1-in. bed of material containing about 30 percent 

glass* with a refractive index slightly above 1.49. 

The bed also contains other minerals including clay*, 

amphiboles*, and quartz*. Light greenish gray 

(5GY7/1). Probably pumice.

421.8 1.8 Clay, similarto clay at depth of 401.7 ft. Maybe slump, 

not core.

430.0 8.2 Clay; colors range from yellowish gray (5Y7/2) downward to yellowish gray (5Y7/1) and light greenish 

gray (5GY7/1) in lower part; massive. Diatoms 

sparse in middle part, grade to abundant in lower part.

436.6 6.6 Clay, grayish-olive (10Y4/2), massive. Gastropod{?) 

fragment noted at 431.9 ft. Still damp. May be 

slump, not core.

440.0 3.4 Clay, yellowish-gray (5Y7/2), massive. Diatoms very 

abundant; ostracodes sparse. Top foot still damp 

and slightly darker.

448.4 8.4 Clay, similar to unit above. Diatoms generally very 

abundant; at 447.3 ft is a 2-in. zone containing sparse 

diatoms, common ostracodes. This 2-in. zone still 

damp, somewhat darker.

450.0 1.6 No core.

453.0 3.0 Clay, yellowish-gray (5Y7-8/2), faintly bedded. Ostracodes abundant, apparently concentrated in beds. 

Grades into unit below,

455.6 2.6 Clay, locally slightly silty, yellowish-gray (5Y7-8/2), 

massive. Ostracodes common.

460.0 4.4 No core.

467.1 7.1 Clay, similar to clay at depth of 436.6 ft. Still damp; 

poorly consolidated. May be slump, not core.

467.8 .7 Clay, yellowish-gray (5Y7/2) to pale-olive (10Y6/2). At 

467.6ft is a-J-in. bed of afine-grained light-gray (N7) 

to medium dark-gray (N4) glass* with a refractive 

index slightly below 1.47; probably opal. Diatoms 

and ostracodes locally abundant.

470.0 2.2 No core.

474.0 4.0 Clay. Similar to clay at depth of 436.6 ft.

479.9 5.9 Clay, yellowish-gray (5Y7/3), massive. Diatoms generally very abundant, ostracodes common.

480.0 .1 No core.

486.4 6.4 Clay, grayish-olive (10Y4/2), still damp; massive. 

Poorly consolidated. Probably slump, not core.

489.2 2.8 Clay, yellowish-gray (5Y7/2) to pale greenish-yellow 

(10Y7/2); generally massive, local faint bedding. 

Ostracodes common.

490.0 .8 No core.

493.9 3.9 Clay. Similar to clay at depth of 486.4 ft.

496.7 2.8 Clay, silty, pale greenish-yellow(10Y7-8/2), massive. 

Ostracodes abundant.

500.0 3.3 Clay, pale greenish-yellow (10Y7-8/2), massive. Ostracodes common.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

OWENS DRILL HOLE 1-Continued

Depth Unit

(f +\ thickness Description

(feet) __________________________________________

501.1 1.1 Clay, silly, and silt; yellowish gray (5Y6/2), still

damp, fissile bedding. Ostracodes common to

abundant . 

508.4 7.3 Clay, slightly silty, pale- greenish-yellow (10Y7/2);

massive, zone of thin bedding at 507.4 ft. 

510.0 1.6 No core.

512.8 2.8 Clay, pale-olive (10Y6/2), massive. 

513.3 .5 Clay, grayish-olive (10Y4/2), massive. Poorly consolidated; still damp. 

514.1 .8 Clay, silty in upper part; pale greenish yellow (7Y7/2).

Laminar bedding in upper and lower part, massive

in middle.

520.0 5.9 No core.

521.4 1.4 Clay, grayish-olive (10Y4/2), massive. Still damp. 

529.8 8.4 Clay, yellowish- gray (5Y7/1) to pale yellowish- gray

(7Y7/2), massive. Sparse diatoms in bottom 1^ ft. 

530.0 .2 No core.

531. 1 1.1 Clay, similar to clay at depth of 521 . 4 ft. 

534.3 3.2 Clay, pale -greenish-yellow (10Y7/2) to light greenishgray (5GY7/1) ; generally massive, local faint bedding.

Diatoms sparse to absent; ostracodes sparse. 

538.7 4.4 Clay, yellowish-gray (5Y7/2); fissile, some faint bedding. Diatoms common, locally abundant; ostracodes

sparse to common. 

540. 0 1. 3 Clay and a little silt, yellowish- gray (5Y6/2); faint laminar bedding. Diatoms sparse to common; ostracodes

abundant. 

544.7 4.7 Clay, similar to clay at depth of 521.4ft. Probably

slump, not core. 

548.3 3.6 Clay, with local beds of silt; pale olive (10Y6/2) to

yellowish gray (5Y7/2); thin to laminar bedding.

Ostracodes common to abundant. 

550.0 1.7 No core.

551. 3 1.3 Clay, similar to clay at depth of 521. 4 ft.

554.8 3.5 Clay, with thin beds of silt; yellowish gray (5Y6/2),

core still damp, thin bedding, grades into unit below.

Ostracodes abundant. 

558. 3 3.5 Clay and a few local thin beds of silty clay, pale greenish-yellow (10Y7/2), generally massive. Ostracodes

sparse .

560.0 1.7 No core. 

561.9 1.9 Clay, similar to clay at depth of 521.4 ft. Poorly consolidated. Probably slump, not core.

562.7 .8 Clay, pale greenish- yellow (10Y7/2), massive. 

564.6 1.9 Clay, pale yellowish- gray (8Y7/2), massive. Ostracodes generally common, abundant near base . 

570.0 5,4 No core. 

572.2 2.2 Clay, greenish-gray (5GY6/1), massive. POOrly Consolidated. Probably slump, not core. 

575.5 3.3 Clay, pale yellowish- gray (7Y7/2), massive. Ostracodes common, grading downward to abundant. 

576.8 1.3 Clay, light olive-gray (5Y6/1), massive. 

580.0 3.2 No core. 

581.4 1.4 Clay, yellowish-gray (5Y6/2); faint bedding. Ostracodes

common; diatoms noted at base.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

^^ OWENS DRILL HOLE 1-Continued 

(feet) thickness Description

582.1 0. 7 Clay, similar to clay at depth of 521.4 ft.

582.7 .6 Clay, yellowish-gray (5Y7/2), massive. Diatoms

common to abundant. Core still damp in upper half. 

589.7 7.0 Clay, yellowish-gray (5Y7/2) to pale greenish-yellow

(10Y7/2), massive. Diatoms sparse. 

590.0 .3 No core.

600.0 10.0 Clay, pale yellowish-gray (7Y7/2), massive. 

607.4 7.4 Clay, grayish-olive (10Y3/2), massive. Core still

damp. Poorly consolidated. Probably slump, not

core. 

609.3 1.9 Clay, light greenish-gray(5GY7/1), massive. Diatoms

sparse.

610.0 .7 No core. 

618.9 8.9 Clay, light greenish-gray(5GY7/1), massive. Diatoms

common in upper part, abundant to very abundant in

lower part; ostracodes sparse. 

620.0 1.1 No core. 

627.4 7.4 Clay, yellowish-gray (5Y8/1), massive. Grades into

unit below. Diatoms abundant; ostracodes sparse. 

630.0 2.6 Clay, yellowish-gray (5Y6-7/2); generally massive,

local fissile bedding in upper part. Diatoms and

ostracodes abundant in upper part grading to sparse

in lower part. 

639.8 9.8 Clay, yellowish-gray (5Y7/2) to pale greenish-yellow

(10Y7/2); generally massive, local thin beds of silt.

Diatoms noted; ostracodes generally sparse, locally

common to abundant. 

640.0 .2 No core.

644.4 4.4 Clay, pale yellowish-gray (7Y7/2) to pale greenishyellow (10Y7/2), massive. Grades into unit below. 

649.8 5.4 Ostracodes sparse. 

649.8 5.4 Clay, locally silty, yellowish-gray (5Y7/2), generally

thin bedded. Ostracodes common to abundant. 

650.0 .2 No core. 

654. 3 4. 3 Clay, silty and locally sandy; local faint beds of sand

and silt. Pale olive (10Y6/2) to pale greenish yellow

(10Y7/2) to yellowish gray (5Y7/1-2). Ostracodes

sparse in upper part grading to common in bottom foot.

659.9 5.6 Clay, locally silty in upper part; yellowish gray (5Y6/2) 

to pale olive (10Y6/2), still damp; generally thin 

bedded in upper 3 ft, remainder massive. Ostracodes 

common to abundant; diatoms locally common in 

bottom 2 ft; several mollusks noted at 659.0 ft.

660.0 .1 No core.

668.4 8.4 Clay, locally silty, yellowish gray (5Y7/2) to pale 

greenish yellow (10Y7/2); thin bedding in top 3 ft, 

remainder generally massive. Ostracodes abundant, 

grading to common in bottom 8 in.

670.0 1.6 No core.

680.0 10.0 Clay, slightly silty, pale yellowish-gray (5Y8/2); generally massive, local faint bedding. Ostracodes 

sparse; diatom noted in upper part; plant remains(?) 

at 670.4 ft. Bottom 2 ft. still damp.

690.0 10.0 No core.
12 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

OWENS DRILL HOLE 1-Continued

Depth Unit

/ .\ thickness Description

(feet) (feet)__________________________________________

693.5 3.5 Clay, grayish-olive (10Y4/2), massive. Core still

damp. Poorly consolidated. Probably slump, not

core. 

694.4 .9 Clay; colors mottled (probably because of differences

in dampness): grayish olive (10Y4/2) and yellowish

gray (5Y7/3). Diatoms common. 

699.4 5.0 Clay, yellowish-gray (5Y7/2); generally massive, some

faint horizontal banding. Local randomly oriented

partings of silt. Diatoms common, locally abundant. 

700.0 .6 No core. 

709.4 9.4 Clay, yellowish-gray (5Y7/2) to pale greenish-yellow

(10Y7/2). Ostracodes abundant to very abundant;

diatoms common in upper part grading to sparse in

lower part.

710.0 .6 No core. 

715.6 5.6 Clay, locally silty, yellowish-gray (5Y7/2) to pale

greenish-yellow (10Y7/2); generally massive, local

faint banding. Diatoms sparse, locally common;

ostracodes common, locally abundant. 

720.0 4.4 No core. 

725.6 5.6 Clay, yellowish-gray (5Y8/1), massive. Diatoms

abundant, locally very abundant; ostracodes sparse;

fish scale noted. 

730.0 4.4 No core. 

738.4 8.4 Clay, locally silty in bottom 3 ft; yellowish gray

(5Y8/1); generally massive. Diatoms abundant to

very abundant; ostracodes sparse to common at

depths from 734.7 to 737.1 ft but not found in rest

of unit.

740.0 1.6 No'core. 

746.8 6.8 Clay, sandy, grayish-olive (10Y4/2), massive. Poorly

consolidated; still damp. 

747.8 1.0 Sand, medium, clayey, pale-olive (10Y5/2), massive.

Still damp.

750.0 2. 2 No core.

750.6 .6 Sand, clayey, similar to sand at depth of 747.8 ft.

752.0 1.4 Clay, dusky yellowish-gray (5Y6/3) to pale-olive

(10Y5/2), massive, Poorly consolidated. 

755.4 3.4 Silt, clayey, pale-olive (10Y7/2-3), massive. Still

damp. Poorly consolidated. 

756.2 .8 Silt, with thin beds of clay. Silt is massive, greenish

yellow (10Y7/2), and consists mainly of silicates* and 

a little clay and a small amount of glass* whose refractive index is 1.50. Clay is dark greenish gray

(5GY4/1), Diatoms sparse.

760.0 3.8 No core.

766.5 6.5 Sand, medium, well-sorted; coarse in bottom 2 ft; 

grayish olive (10Y4/2); massive. Still damp. Poorly

consolidated,

767.3 .8 Sand,fine, consisting almost entirely of thin triangularshaped wafers of volcanic glass*. Refractive index 

of glass about 1.503. Pale olive (10Y6/2) grading 

down to medium dark gray (N4) and medium light 

gray (N6). Massive. Still damp.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

OWENS DRILL HOLE 1-Continued

De Unit

/ , \ thickness Description (feet) (feet)

768.2 0.9 Clay, grading down to sandy silt; light greenish gray 

(5GY7/1); mostly massive, local faint thin bedding. 

' Top 4 in. is darker; still damp.

770.0 1.8 No core.

772.8 2.8 Sand, very fine to coarse, average medium; grayish 

olive (10Y4/2); massive. Poorly consolidated.

775.6 2.8 Sand, medium in upper part grading downward to coarse; 

light greenish gray (5GY7/1); massive. Poorly consolidated.

780.0 4.4 No core.

781.4 1.4 Sand, coarse; top one-third contains many fragments 

up to 3 mm in size; pale olive (10Y6/2); massive. 

Poorly consolidated. Grades into unit below.

783.4 2.0 Silt, clayey in top 4 in. and in bottom 7 in.; yellowish 

gray (5Y7/2) in upper part grading down to pale 

greenish yellow (10Y7/2); faint bedding in 'lower 

part, remainder is massive.

790.0 6.6 No core.

796.0 6.0 No core. Core was destroyed while being removed 

from core barrel. Consisted mainly of coarse clayey 

sand; color when wet was dark greenish gray (5GY4/1).

799.4 3.4 Clay, sandy in upper part, locally sandy in lower part; 

light greenish gray (5GY7/1); massive.

800.0 .6 No core.

801.4 1.4 Sand, coarse, light greenish-gray (5GY7/1), massive. 

Poorly consolidated.

806.4 5.0 Sand, silty, clay matrix; pale olive (10Y5-6/2); massive. Still damp. Poorly consolidated.

807.0 .6 Clay, sandy, light'greenish-gray (5GY7/1), massive.

810.0 3.0 No core.

818.4 8.4 Sand, fine, clayey in top 1.6 ft; grayish olive (10Y4/2) 

where damp to yellowish olive gray(7Y6/2) where 

dry; massive. Poorly consolidated.

820.0 1.6 No core.

825.6 5.6 Sand, medium to very fine, locally clayey, pale-olive 

(10Y6/2), massive. Poorly consolidated.

830.0 4.4 No core.

835.6 5.6 Sand, medium to very fine, similar to sand at depth of 

 ? 825.6ft.

840.0 4.4 No core.

843.7 3.7 Clay and sand. Clay in top third grades into a transitional zone of intermixed pockets of clay and very 

fine sand; this, in turn, grades to very fine sand at 

base. Colors mottled: light olive gray (5Y5/3) to 

grayish olive (10Y4/2). Massive. Still damp; poorly 

consolidated. Grades into unit below.

846.8 3.1 Silt to very fine sand with local clay pockets; yellowish 

gray (5Y6/2) to pale olive (10Y6/2), upper part is 

darker and still damp; massive. Poorly consolidated. 

j 850.0 3.2 No core.

856. 3 6.3 Silt to medium sand, some clay; sorting generally poor; 

locally good; pale olive (10Y6/2) to dusky yellowish 

gray(5Y6/3) to light greenish gray (5GY7/1); massive. Poorly consolidated.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

OWENS DRILL HOLE 1-Continued

Depth Unit

(feet) thickness Description

(feet) __________________________________________

857.2 0.9 Clay, locally silty, yellowish-gray (5Y7/1) to light

greenish-gray (5GY7/1), massive. 

860.0 2.8 No core. 

862.8 2.8 Silt grading down to fine and medium sand, yellowish

gray (5Y7/2) to light greenish gray (5GY7/1) to

light olive gray (5Y6/1); massive. Sand is poorly

consolidated. 

865.6 2.8 Sand, coarse, well-sorted, clean; grades down to

medium sand, poorly sorted; light olive gray(5Y5/l)

to dusky yellowish gray (5Y6/3), massive. Poorly

consolidated.

870.0 4.4 No core. 

870.8 .8 Sand, very fine, grading down to silt; yellowish gray

(5Y7/1); massive. 

873.3 2.5 Clay, light greenish-gray (5GY7/1); local faint banding. Diatoms very abundant. 

874. 1 .8 Sand, medium to coarse, clayey in upper part; moderate olive brown (5Y4/4) to dusky yellow (5Y5/4);

massive. Still damp. 

880.0 5.9 No core. 

886. 2 6.2 Sand, fine to medium, fairly well sorted, grayish-olive

(10Y4/2). Still damp. Poorly consolidated. 

890.0 3.8 Clay, light greenish-gray (5GY7/1), massive. Diatoms

common to abundant; ostracode noted. 

893.1 . 3.1 Sand, fine to very fine, clayey in lower part; grayish

olive (10Y4/2); massive. Still damp. Poorly consolidated. Probably slump, not core. 

895.6 2.5 Clay, light greenish-gray (5GY7/1), massive. Diatoms

and diatom casts sparse in upper part grading to

abundant in lower part. 

900.0 4.4 No core. 

904.7 . 4.7 Clay, a little silt at base; light greenish gray (5GY8/1) to

yellowish gray (5Y7/1); massive. Diatoms abundant,

locally common; diatom .casts abundant in top 1.6 ft. 

910.0 5.3 No core. 

912.1 2.1 Silt grading down to medium and coarse sand, pale

greenish yellow (10Y7/ 2) to light olive gray(5Y5/l);

massive. Poorly consolidated. 

913.6 1.5 Clay, yellowish- gray (5Y8/1), massive. Diatoms

abundant to very abundant. 

920.0 6.4 No core.

CHMA DRILL HOLE MD-1

[Seventy percent of core recovered]

Depth ..Jh" _

/ r v thickness Description

3,5 3.5 Sand, very fine to coarse, average medium; a little

silt and clay; grayish yellowish orange (10YR6/5), 

massive. Badly shattered during drilling.

5. 5 2.0 Sand, very fine to coarse, average medium; dusky yellow (5Y5/4); massive.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

CHINA DRILL HOLE MD-1- Continued

Depth Unit

(feet) thickness Description

v (feet)

10. 0 4. 5 No core.

11. 6 1. 6 Clay, very micaceous, slightly sandy at base; grayish 

olive (10Y4/2), still damp; massive. Small gastropod noted at 11.4ft.

12. 8 1.2 Sand, fine to medium, locally clayey; fair sorting;

grayish olive (10Y4/2), still damp; massive. 

20. 0 7. 2 No core. 

23.5 3.5 Clay, slightly silty at base; light yellowish gray (5Y8/2)

where dry, still damp in lower half; massive. Ostracodes sparse to common; gastropod cast noted; plant

fibers locally sparse. 

24. 5 1.0 Clay and silt, local fine sand; pale olive (10Y5/2), still

damp; indistinct thin bedding. Ostracodes sparse to

common. 

29.3 4.8 Clay, locally silty,, moderate yellowish-brown (10YR5/5)

and pale-olive (10Y6/2), still damp; generally massive, local pronounced laminar bedding. Ostracodes

noted. 

30.0 .7 Sand, fine, clay matrix; grayish olive (10Y4/2); generally massive. Ostracodes noted. In middle of

unit is a ^-in. bed of grayish-yellow (5Y7/4) clay. 

30. 9 .9 Gravel, grading down to clay; colors mottled: grayish

olive (10Y4/2) to yellowish gray (5Y6/3). Poorly

consolidated. May be slump, not core.

36. 2 5. 3 Sand, fine to medium, clay matrix; proportion of clay 

higher at base; pale olive (10Y5-6/2); massive. 

Grades into unit below.

37. 8 1.6 Clay, contains up to about 5 percent fine to coarse sand; 

grayish olive (10Y4/2), still damp; massive.

40. 0 2. 2 Clay, contains up to about 5 percent very fine to coarse 

sand; pale greenish yellow (10Y7/2), damp parts 

somewhat darker; generally massive, local laminar 

bedding. Up to about 1 percent calcite* as clusters 

of euhedral crystals.

42. 4 2. 4 Clay, local zones contain silt and sand; grayish olive 

(10Y4/2), still damp; massive. Calcite noted, similar to that in unit above. One small mollusk noted.

48. 7 6.3 Sand, very fine to coarse, average medium, clay matrix; 

pale greenish yellow (10Y7/2); massive.

49. 1 .4 Clay, slightly sandy; pale greenish yellow (10Y7/2), 

streaks of grayish orange (10YR7/5); massive.

50. 0 .9 No core.

52. 3 2. 3 Clay, slightly sandy, similar to clay at depth of 49. 1 ft.

56. 0 3. 7 Clay, locally silty or sandy; grayish olive (10Y4/2) and 

very pale orange (10YR8/2), still damp; massive. 

Rhombs of calcite noted.

57. 7 1. 7 Clay, slightly sandy; pale olive (10Y6/2) where dry,

still damp in lower part. Contains clustered rhombs

of calcite. 

59.0 1.3 Sand, medium, grades down to sandy clay; pale olive

(10Y5-6/2); massive. 

60. 0 1. 0 No core. 

65. 3 5. 3 Clay, slightly sandy, grayish-olive (10Y4/2), still damp;

massive. Shell fragments noted near top.
16 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

CHINA DRILL HOLE MD-1 -Continued

Depth

_ (feet)

(feet) thickness Description 

* '

66. 5 1.2 Clay, pale greenish-yellow (10Y7/2); local faint bed-

. ding. Ostracodes noted.

68.4 1.9 Clay, sandy, grayish -yellow -green (5GY7-8/2); generally massive, local contorted laminar bedding. At 

67. 3 ft there is a 1-in. zone of clay containing pockets 

of calcite as medium sand-sized rhombs. 

70.0 1.6 No core.

75. 6 5. 6 Clay with variable amounts of sand; yellowish gray 

(5Y7/3) to pale olive (10Y5/2), somewhat darker in 

damp parts; local faint bedding. Calcite crystals 

noted locally.

80. 0 4. 4 No core.

83. 8 3. 8 Clay, locally sandy, grayish-olive (10Y4/2),still damp; 

massive. Clusters of calcite rhombs noted locally.

87. 1 3. 3 Clay, grades to silt in bottom foot. Colors range from 

moderate yellow (5Y6/6) with streaks of pale olive 

(10Y6/2) in upper part to dusky yellow (5Y6/4) in 

lower part. Thin to laminar color banding; locally 

massive. Galcite clusters noted in upper part. 

90.0 2.9 No core.

96. 9 6. 9 Clay, locally sandy, similar to clay at depth of 83. 8 ft. 

100.0. : 3.1 No core. 

101. 3 1.3 Clay, sandy. Sandy material forms about 10 percent of

core and consists of rhombs of calcite.

105. 1 3. 8 Clay, slightly sandy, grayish-olive (10Y4/2) to paleolive (10Y6/2), still damp; massive. Contains some 

calcite as rhombs. 

110.0 4.9 No core.

114. 9 4. 9 Clay, -slightly sandy, and a little calcite; grayish olive 

(10Y4/2) to moderate olive brown (5Y4/4), still damp; 

massive. Grades into unit below.

119.0 4.1 Clay, grades down into crystal gravel. Gaylussite* 

crystals range from about 10 percent of the material 

in upper part to about 60 percent at base; they range 

in size up to about 10 mm, average about 4 mm. 

Microscopic examination shows that calcite* , in minor 

amounts, extends at least down to middle of unit and 

is coexistent with gaylussite*. Dusky yellowish gray 

(5Y6-7/3) and pale olive (10Y5-6/2); locally still 

damp. Massive. 

120.0 1.0 No core.

124. 5 4. 5 Clay; contains about 5 percent gaylussite and a little 

calcite* as sand-sized crystals; probably some silicate sand.

127. 6 3. 1 Sand, crystal, coarse to very coarse at top grading to

fine at bottom; clay matrix. Sand is mostly gaylussite,

some calcite. Light greenish gray (5GY7/1), streaks

. of dark yellowish orange (10YR6/5); pseudobedding

defined by color changes. 

130.0 2.4 No core. 191, o 1.0 ciay; contains gaylussite ana a little calcite which range

from a trace at top and bottom to about 30 percent of 

the material in the middle of the unit; crystals average sand size; grayish olive (10Y4-5/2)'and dusky 

yellowish gray (5Y6/3), still damp; massive.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

CHINA DRILL HOLE MD-1-Continued

17

Depth Unit

/- j.\ thickness Description (feet) (feet)

137. 2 2.4 Sand, crystal; gaylussite and a few calcite crystals in 

a clay matrix; crystals average very coarse sand 

size; grayish olive (10Y4/2) to pale olive (10Y6/2), 

still damp; massive.

140.0 2.8 No core.

146. 3 6. 3 Clay; sand-sized gaylussite and a few calcite crystals 

constitute up to 10 percent of the material; grayish 

olive (10Y4/2), still damp; massive.

147.4 1.1 Clay, trace of calcite crystals; pale olive (10Y6/2), 

small streaks of grayish orange (10YR6/4); massive.

150.0 2.6 No core.

152.3 2.3 Clay, a little calcite; grayish olive (10Y4/2), still damp; 

massive.

154.2 1.9 Clay, contains up to 10 percent gaylussite; grayish olive 

(10Y4/2), moderate olive brown (5Y4/4), and light 

olive gray (5Y5/2), still damp; massive.

156.8 2.6 Gravel, crystal, grading down to crystal sand; consists 

of gaylussite crystals up to 5 mm in size in a clay 

matrix; pale olive (10Y6/2) where dry, upper part 

still damp; indistinct bedding in lower part.

160.0 3.2 No core.

161.0 1.0 Gravel, crystal; gaylussite crystals and fragments up 

to about 6 mm in size in matrix of clay which makes 

up 30 or 40 percent of the core; pale olive (10Y6/2) 

to greenish gray (5GY6/1); local thin bedding caused 

by layered concentration of gaylussite crystals.

161,. 5 . 5 Clay, contains about 5 percent sand-sized crystals of 

gaylussite; colors mottled, dusky yellowish gray 

(5Y6/3) and grayish olive (10Y4/2), still damp; massive.

162.6 1.1 Gravel, crystal; gaylussite crystals and fragments up 

to about 15 mm in size in a matrix of clay which 

makes up about 30 to 40 percent of core; grayish 

olive (10Y4/2), still damp; massive; crystals randomly oriented.

163.0 .4 Sand and clay interbedded; sand is fine to medium, 

consists mainly of gaylussite and a little biotite and 

other silicates in a clay matrix. Locally, gaylussite forms a cement that shows a single large cleavage face. Pale olive (10Y6/2) and dusky yellowish 

gray (5Y6/3); thin bedding.

164. 3 1.3 Crystal gravel, similar to crystal gravel at depth of 

162. 6 ft.

165.2 .9 Sand, crystal, grading downward from coarse to very 

fine. Sand is mainly quartz*, with a trace of feldspar*, cemented by gaylussite*. Light greenish gray 

(5GY7/1-2); indistinct thin bedding.

170.0 4.8 No core.

172. 7 2. 7 Clay, with about 3 percent sand consisting of silicates 

and fragments of gaylussite; grayish olive (10Y4/2); 

massive.

176. 9 4. 2 Silt and very fine sand, locally clayey, light greenishgray (5GY7/1) to pale greenish-yellow (10Y7/2); 

massive. At 172.8 ft there is a 2-in. bed of clay 

containing about 3 percent gaylussite.
18

CHINA DRILL HOLE MD-1-Contirmed

D th Unit

/ .s thickness Description

* ____(feet)__________________________________________

180.0 3.1 No core.

180.4 .4 Sand, very fine; consists of fragments and crystals of 

quartz, mica, gaylussite, and probably calcite; yellowish gray (5Y7/2) and pale .olive (10Y5/2); a little 

thin indistinct bedding.

182.8 2.4 Clay, with a small amount of gaylussite and a trace of 

calcite; grayish olive (10Y4/2); massive.

190.0 7.2 No core.

192.8 2. 8 Clay, with a small amount of gaylussite and a trace of 

calcite; grayish olive (10Y4/2); massive. At base is 

a 2-in. bed of fine gaylussite sand, well indurated, 

with a clay matrix.

200.0 7.2 No core.

204.1 4.1 Clay, slightly sandy, grayish-olive (10Y4/2) to moderate olive-brown (5Y4/2), still damp; massive.

210.0 5.9 No core.

210.7 .7 Clay, slightly sandy, similar to clay at depth of 

204.1 ft.

213.9 3.2 Sand, very fine; locally clayey. Sand consists of quartz, 

silicates, and calcite. Pale olive (10Y6/2) to grayish 

olive (10Y4/2). Thin, indistinct bedding.

214.3 .4 Sand, fine, clayey; yellowish-gray (5Y7/2), massive.

220.0 5.7 No core.

225. 9 5.9 Clay, with crystals and fragments of gaylussite; sandy 

in upper part; greenish olive (10Y4/2) to pale olive 

(10Y6/2), still damp; massive. Grades into unit below. At 221.9 ft there is a pocket of sand containing 

several small gastropod shells. At 222.7 ft two 

rounded pebbles of dark-gray limestone were noted.

227.7 1.8 Clay, slightly silty, sandy at base; pale greenish yellow 

(10Y7/2) and yellowish gray (5Y6/2); thin indistinct 

bedding. Ostracod.es common to abundant.

229. 9 2. 2 Silt, clayey, yellowish-gray (5Y8/1) to pale greenishyellow (10Y7/2); thin indistinct bedding.

230.0 .1 No core.

235. 9 5. 9 Silt grading down to silty clay, dusky yellowish-gray 

(5Y6/3) to pale olive-gray (7Y6/2); thin indistinct 

bedding.

240.0 4.1 No core.

242. 4 2. 4 Clay, slightly sandy, grayish-olive (10Y4/2) to dark 

greenish-gray (5GY4/1), still damp; massive. Poorly 

consolidated.

245. 2 2.8 Clay, slightly silty, light olive-gray (5Y5/2) to dusky 

yellowish-gray (5Y6/3); local thin bedding.

250.0 4.8 No core.

260.0 10.0 No core.

265.2 5.2 Clay; grayish olive (10Y4/2) to dark greenish gray 

(5GY4/1) with streaks of moderate yellowish brown 

(10YR5/4), still damp; massive. Poorly consolidated 

in upper part. Grades into unit below.

268.8 3.6 Clay; grayish olive (10Y4/2) to pale olive (10Y6/2) 

with streaks of moderate yellowish brown (10YR5/4), 

still damp; thin to laminar bedding.

'270.0 1.2 No core.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

CHINA DRILL HOLE MD-1-Continued

/ ,\ thickness Description (feet) (feet)

271.4 1.4 Clay, grayish-olive (10Y4/2), still damp; massive. 

277.8 6.4 Clay, yellowish-gray (5Y6-7/2); thin to laminar bedding defined by color changes.

278.4 .6 Clay, grayish-olive (10Y4/2), still damp; massive. 

280.0 1.6 No core.

281. 3 1.3 Clay, similar to clay at depth of 278.4 ft.

282. 3 1.0 Clay, pale-olive (10Y5/2) to light olive-gray (5Y5-6/2), 

still damp; bedding thin to laminar; fissile fracture. 

Ostracodes common to abundant.

285.1 2.8 Clay, grayish-olive (10Y4/2), massive. At 284. 3 ft a 

few basalt(?) pebbles up to 15 mm across were noted.

290.0 4.9 No core.

295. 3 5. 3 Clay, grayish-olive (10Y4/2), still damp; massive.

299. 5 4. 2 Clay, light olive-gray (5Y6/1), yellowish-gray - (5Y8/1), 

and yellowish-gray (5Y7/2), locally still damp; bedding thin to laminar, locally massive; bedding defined by color changes.

300.0 .5 Clay, pale-olive (10Y5-6/2), massive.

305.1 5.1 Clay, slightly sandy, grayish-olive (10Y4/2), still 

damp; massive.

306.1 1.0 Clay, slightly silty, pale -olive (10Y6/2) to yellowishgray (5Y7/2); laminar bedding.

310.0 3.9 No core.

311.2 1.2 Clay, grayish-olive (10Y4/2), still damp; massive. 

Poorly consolidated.

312. 8 1.6 Clay interbedded with silt and fine sand, grayish-olive 

(10Y4/2) to light olive-gray (5Y5/2) to yellowishgray (5Y7/2), still damp; thin to laminar bedding; 

fissile fracture. Ostracodes sparse.

320.0 7.2 Silt and very fine sand, locally clayey; pale olive 

(10Y5-6/2) and yellowish gray (5Y7/2), locally damp 

and darker; faint thin bedding defined by color changes. Ostracodes (?) noted.

324.2 4.2 Clay, slightly sandy, similar to clay at depth of 

305.1 ft. May be slump, not core.

324.9 .7 Clay, silty, pale olive-gray (7Y5/2), still damp; thin 

faint bedding. Ostracodes sparse.

330.0 5.1 No core.

331.2 1.2 Clay, slightly sandy, similar to clay at depth of 

305.1 ft.

335. 2 4.0 Clay, slightly silty, pale olive-gray (7Y6/2) to dusky 

yellowish-gray (5Y6/3); thin to laminar bedding.

336. 5 1. 3 Silt, clayey, grading down to clay; light olive gray 

(5Y5-7/2) to dark greenish gray (5GY4/1) to pale 

olive (10Y6/2), still damp; thin bedding. Ostracodes 

locally abundant.

340.0 3.5 No core.

344.1 4.1 Clay, locally silty, light olive-gray (5Y5/2) to grayisholive (10Y4/2) to pale greenish-yeUow (10Y7/2), still 

damp; thin bedding defined by color changes. Ostracodes locally common.

345.8 1.7 Clay, slightly sandy, grayish-olive (10Y4/2) to dark 

greenish-gray (5GY4/1), still damp; massive.

350.0 4.2 No core.
90

 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

CHINA DRILL HOLE MD-1-Continued

Depth Unlt

(feet) thickness Description

(feet)__________________________________________

353.9 3.9 Clay, slightly sandy, grayish-olive (10Y4/2) to dark 

greenish-gray (5GY4/1), still damp; massive. Ostracodes sparse at top.

358.1 4. 2 Clay interbedded with silt, grayish-olive (10Y4-5/2) 

and light olive-gray (5Y5-6/2); distinct thin to laminar bedding defined by both color and compositional 

changes. Ostracodes locally sparse between 354.9 

and 355. 9 ft.

360.0 1.9 No core.

360.4 .4 Clay, slightly sandy, grayish-olive (10Y4/2) to dark 

greenish-gray (5GY4/1), still damp; massive.

366.5 6.1 Clay and silt alternating, dusky- yellowish-gray 

(5Y5-6/3) to pale olive (10Y6/2); irregular bedding 

ranges from laminar to 2 in. in thickness. Ostracodes locally sparse in silty parts.

367.3 .8 Sand, very fine, yellowish-gray (5Y7/2), massive.

369.0 1.7 Clay and silt alternating, similar to clay and silt at 

depth of 366. 5 ft.

369.2 .2 Sand, medium, yellowish-gray (5Y7/2), massive.

370.0 . 8 Silt and a little clay, pale olive-gray (7Y7/2) to dusky 

yellowish-gray (5Y6/3), faint thin bedding.

373.1 3.1 Clay, slightly sandy, grayish-olive (10Y4/2) to dark 

greenish-gray (5GY4/1), still damp; massive.

374.0 .9 Silt, pale olive-gray (7Y6/2) to dusky yellowish-gray 

(5Y6/3), massive.

374. 7 . 7 Clay and a little silt, pale-olive (10Y5/2). Silt forms 

laminar beds. At base is a 1-in. bed of fine-grained 

opal*; very pale orange (10YR8/4) and very pale 

purple (5P8/2).

375.3 .6 Silt and a little clay, pale-olive (10Y5-6/2) to pale 

olive-gray (7Y7/2); local thin bedding.

380.0 4.7 No core.

380.9 .9 Clay, slightly sandy, similar to clay at depth of 

373.1ft. Includes a 1-in. pebble of dark fine-grained 

metamorphic(?) rock.

382.0 l.l' Clay, silty, pale olive-gray (7Y6/2) to pale-olive 

(10Y6/2), still damp; massive. At base is a 1-in. 

bed of medium-gray (N5) and moderate orange-brown 

(10YR5/5) fine-grained opal.

390.0 8.0 No core.

39Q.8 .8 Clay, Slightly sandy, similar to clay at depth of 

373.1ft.

398.8 8.0 Silt and clay alternating, yellowish-gray (5Y7/2) to 

pale-olive (10Y6/2); irregular beds range from laminar to 2 in. in thickness.

400.0 1.2 No core.

400.8 .8 Clay, slightly sandy, similar to clay at depth of

373.1 ft. 

402 4 16 Silt grading down to clay, yellowish-gray (5Y6-7/2) to

pale-OliVe (1016/2)10pale ^enish-yeUow(10Y8/2);

bedding thin to laminar. Ostracodes locally COMOfl 

in upper part, locally abundant in lower part.

407.7 5. 3 Silt, a little clay; light greenish gray (5GY7/1) to 

yellowish gray (5Y7/2); generally massive; local 

thin banding defined by color changes and clay.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

CHINA DRILL HOLE MD-1 -Continued

Depth Unit

(feet) thickness Description 

(feet)

410.0 2.3 No core.

411. 2 1.2 Silt, a little clay, similar to silt at depth of 407. 7 ft.

411.6 .4 Clay, slightly sandy, similar to clay at depth of

373. 1 ft.

417. 2 5. 6 Silt, a little clay, similar to silt at depth of 407. 7 ft. 

420. 0 2. 8 No core. 

420. 6 . 6 Clay, slightly silty, grayish-olive (10Y4/2) and dark

greenish-gray (5GY4/1), still damp; massive. Grades

into unit below. 

426.6 6.0 Clay, slightly silty, yellowish -gray (5Y7/2) to paleolive (10Y6/2), top foot stiU damp, slightly darker;

massive zones alternate with laminar bedded zones.

At 426. 3 ft there is al-in. bed consisting essentially

of an isotropic* material with a refractive index of

1. 47; may. be glass or opal. 

430. 0 3. 4 No core. 

432. 6 2. 6 Clay, slightly silty in lower part; grayish olive

(10Y4/2) to dark greenish gray (5GY4/1), still damp;

massive. 

440.0 7.4 Silt and clay, yeUowish-gray (5Y7/2), pale-olive

(10Y4-6/2), and light greenish-gray (5GY7/1). Bedding in top 3 ft is distinctly varvelike; remainder of

unit generally massive with faint local laminar bedding. 

447. 2 7. 2 Clay; slightly sandy, especially in bottom 6 in. ;

grayish olive (10Y4/2) and dark greenish gray

(5GY4/1), still damp; massive.

450. 0 2. 8 Siltgradingto very fine sand in bottom foot, yellowishgray (5Y7/1) to light greenish-gray (5GY7/1); generally massive, local faint bedding. Trace of glass 

noted in fine sand near the base.

451. 8 1.8 Clay, grayish-olive (10Y4/2) and dark greenish-gray

(5GY4/1), still damp; massive. 

456. 7 4. 9 Sand, very fine; a little clay and silt; yellowish -gray

(5Y7-8/1), locally still damp, somewhat darker; generally massive. Clay and silt form local thin beds. 

460. 0 3. 3 No core. 

462.8 2.8 Silt, a little clay; yellowish gray (5Y7/1), light

greenish gray (5GY7/1), and pale greenish yellow

(10Y7/2); generally massive, local laminae of clay in

lower half. 

463. 9 1. 1 Clay and silt, a little sand; pale olive (10Y5/2) to

yellowish gray (5Y7/2); laminar bedding. Ostracodes common to abundant. 

470. 0 6. 1 No core. 

470.4 .4 Clay, silty, grayish-olive (10Y4/2), still damp; massive. 

472.7 2.3 Silt and clay, pale-olive (10Y6-7/2) and light greenishgray (5GY8/1); thin to laminar bedding defined by

clay alternating with silt. At 472. 1 ft there is a i-in.

bed of very light gray (N8) fine-grained isotropic*

material which has a refractive index of 1. 47 and

may be either opal or glass. 

476.0 3.3 Clay, slightly sandy, grayish-olive (10Y4/2) and dark

greenish-gray (5GY4/1), still damp; massive.
22 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

CHINA DRILL HOLE MD-1-Continued

Unit

thickness Description 

( feet)_________________________________________

480.0 4.0 No core.

481. 2 1.2 Silt and a little clay, yellowish-gray (5Y8/1) and paleolive (10Y5/2); bedding consists of i-in. beds of silt 

separated by partings of clay. At base of this unit 

there is a |-in. zone of fine-grained opal* with a refractive index of about 1.465; also present are potash 

feldspar*, quartz*, calcite*, and an opaque material, 

which form about 10 percent of the total.

486. 6 5.4 Silt and clay; silt predominates in the top and bottom 

thirds, clay predominates in the middle; light 

greenish gray (5GY7-8/1), pale olive (10Y6-7/2), 

and yellowish gray (5Y7/2); indistinct thin bedding, 

locally massive, especially in clay. Ostracodes 

sparse. At 484.0 ft there is a |-in. bed of finegrained light-gray (N8) material, megascopically 

similar to that at 472.1 ft.

490.0 3.4 No core.

490. 7 .7 Clay, slightly sandy, similar to clay at depth of 476.0 ft.

491.5 .8 Clay, silt, and compact fine-grained opal(?) in an irregular mixture; yellowish gray (5Y7/2) to pale 

greenish yeUow (10Y7/2) to grayish olive (10Y4/2); 

probably massive, badly shattered during drilling. 

Opal(?) is megascopically similar to that at 481.2 ft.

492.2 .7 Sand, very fine, yellowish-gray (5Y7/2) to pale 

greenish-yellow (10Y7/2), faint thin bedding.

497.5 5.3 Clay and silt, pale-olive (10Y6-7/2) and dusky 

yellowish-gray (5Y6/3); bedding thin to laminar, faint 

in upper part, distinct in lower part; local massive 

zones. Ostracodes locally common.

500.0 2. 5 Silt and fine sand, some medium to coarse sand in 

lower half; light greenish gray (5GY7/1); generally 

massive; local faint bedding.

502. 2 2.2 Clay, contains a few pebbles or concretions; grayisholive (10Y4/2) and dark greenish-gray (5GY4/1), 

still damp; massive.

507.8 5.6 Sand, fine, coarser in top foot; yellowish gray (5Y6/2) 

to pale olive (10Y6/2), still damp; faint thin bedding.

510.0 2.2 No core.

511.3 1.3 Silt and very fine sand, a little clay; yellowish ^gray

(5Y7/2); faint bedding at top.

517.6 6.3 Clay and silt, pale-olive (10Y6-7/2) and yellowish-gray 

(5Y7/2); laminar bedding defined by alternating clay 

and silt and color changes; fissile fracture. At 

.515.7 ft there is a f-in. bed of fine-grained very

light gray (N8) isotropic* material with an average

index of 1.475; probably opal.

520.0 2.4 No core.

522.2 2.2 Clay, sandy, grayish-olive (10Y4/2) and dark greenishgray (5GY4/1), still damp; massive. Poorly consolidated.

523.6 1.4 Sand, fine; contains fine-grained calcite; yellowish 

gray (5Y7/1-2) and light greenish gray (5GY7/1); 

faint thin bedding.

530.0 6.4 No core.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

CHINA DRILL HOLE MD-1 Continued

Depth (feet) thickness Description

^ ' _____ (feet)

540. 0 10. 0 Clay, silty, less silty in bottom foot; yellowish gray

(5Y7/1) to light greenish gray (5GY7/1); generally

thin bedded with fissile fracture, locally massive. 

542. 0 2. 0 Clay, slightly sandy in lower part; dark greenish gray

(5GY4/1) and grayish olive (10Y4/2), still damp;

massive. 

548. 1 6. 1 Clay, slightly silty, pale olive-gray (7Y6/2) to paleolive (10Y6-7/2) to light olive-gray (5Y5-6/2); laminar bedding; fissile fracture. 

548.2 .1 Glass*, fine-grained, very light gray (N8). In |-in.

beds separated by partings of a darker material.

Isotropic; refractive index about 1. 478.

549. 5 1.3 Clay and a little silt, pale-olive (10Y6-7/2); thin to 

laminar bedding. Ostracodes sparse.

550. 0 . 5 No core.

555. 3 5. 3 Clay, sandy, a few pebbles or concretions; grayish

olive (10Y4/2) and dark greenish gray (5GY4/1),

still damp; massive. 

558.4 3.1 Clay, silty, pale-olive (10Y6-7/2) and yellowish-gray

(7Y7/2); laminar bedding; locally massive.

560. 0 1. 6 No core.

561. 6 1. 6 Clay, slightly sandy at base; grayish olive (10Y4/2) to 

dark greenish gray (5GY4/1), still damp; massive.

567. 2 5. 6 Sand, very fine to fine, grades downward to medium, 

locally clayey; yellowish gray (5Y6-7/2) to pale 

olive (10Y6/2), still damp and slightly darker in 

upper part; faint thin bedding.

570. 0 2. 8 No core.

578. 5 8. 5 Clay, local small pockets of very coarse to medium 

sand; grayish olive (10Y4/2) and dark greenish gray 

(5GY4/1), still damp; massive.

579.3 .8 Sand, fine, yellowish-gray (5Y6/2); thin to laminar 

bedding.

580. 0 . 7 No core.

582. 2 2. 2 Sandy clay grading down to very fine clayey sand, 

grayish-olive (10Y4/2) to light olive -gray (5Y5/2) 

and dark-<greenish-gray (5GY4/1), still damp; massive.

590. 0 7. 8 Clay, a little silt; very fine sand in top 6 in. ; yellowish 

greenish gray (7Y5-6/2) and grayish olive (10Y4/2) 

to pale greenish yellow (10Y7/2); lighter layers are 

silt, darker layers are clay; bedding generally varvelike; locally massive. Ostracodes (?) noted.

591.4 1.4 Clay and silt, light olive-gray (5Y4-6/2) to pale-olive 

(10Y5-7/2); bedding generally varvelike, locally massive.

592.8 1.4 Clay, slightly silty, yellowish-gray (5Y6-7/2); faint 

thin bedding.

595. 8 3. 0 Clay, yellowish-gray (5Y6-7/2) and light greenishgray (5GY7/1); faint thin bedding in upper part grading to varvelike bedding in lower part.

600. 0 4. 2 No core.

604. 9 4. 9 Clay with very thin beds of silt, light olive -gray 

(5Y6/1) to greenish-gray (5GY6/l);thin to varvelike 

bedding.
24

'GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

. .. CHINA DRILL HOLE MD-1-Ccmtinued

Depth Unit

(feet) thickness . Description 

_________(feet)__________________________________________

606. 6 ' 1.7 Clay with many small pebbles, dark greenish-gray 

(5GY4/1), still damp; massive.

607.1 .5 Silt and clay interbedded, pale olive-gray (7Y6/2); 

thin bedding.

610.0 2.9 No core.

612.8 2.8 Silt, with interbedded clay, pale-olive (7-10Y6/2); 

laminar bedding. Grades into unit below.

617.6 4.8 Clay with interbedded silt, yellowish-gray (5Y6/2) to 

pale-olive (10Y6/2); laminar bedding.

618.4 .8 Sand, fine, clayey; contains many concretions (or 

rounded fragments?) of a fine-grained white calcareous substance; yellowish-gray (5Y7/2) to pale 

greenish-yellow (10Y7/2); thin bedding; concretions 

are concentrated in beds. Top 2 in. mostly clay.

620.0 1.6 No core.

624.3 4.3 Clay, slightly sandy, pale olive-gray (7Y6/2) and 

greenish-gray (5GY5/1), top 3 ft still damp and 

darker; massive.

625. 5 1. 2 Sand, medium to coarse, yellowish-gray (5Y6/2); faint 

thin bedding in upper part.

628. 8 3. 3 Clay, slightly silty, yellowish-gray (5Y7/2) to paleolive (10Y6/2); laminar bedding with partings of silt.

630.0 1.2 No core.

633.6 3.6 Clay, locally silty, pale-olive (10Y6/2); laminar bedding; generally fissile. Ostracodes locally common.

638.0 4.4 Clay, yellowish-gray (5Y6-7/2) to pale greenishyellow (10Y7/2); thin to laminar bedding; chunky 

fracture. Ostracodes locally common.

638.7 .7 Clay with many thin white (N9) beds of calcite*; paleolive (10Y6/1); thin bedding. Ostracodes locally 

common.

639.4 .7 Silt, clayey, pale olive-gray (7Y6/2), massive.

640.0 .6 No core.

642.2 2.2 Clay, sandy, pale-olive (10Y6/2) to yellowish-gray 

(5Y6/2), massive.

648. 3 6.1 Clay, slightly silty, pale olive-gray (7Y6/2) to paleolive (10Y6/2) to light greenish-gray (5GY7/1); thin 

bedding; fissile except in top foot. Grades into unit 

below.

649.8 1.5 Silt, clayey, pale olive-gray (7Y6/2); faint thin bedding. 

Contains small pockets of fine-grained light yellowish-gray (5Y9/1) calcite* generally concentrated 

along bedding planes.

650.0 . .2 No core.

653.0 3.0 Clay, slightly sandy, grayish-olive (10Y3-4/2), still 

damp; massive.

657.8 4.8 Clay, locally silty, yellowish-gray (5Y6/2-3) to pale - 

olive (10Y6/2); thin to laminar bedding; locally fissile. 

Ostracodes common in upper part.

660.0 2.2 No core.

664.3 4.3 Clay, grayish-olive (10Y4/2) to dark greenish-gray 

(5GY4/1), still damp; massive. Poorly consolidated.

666.3 2.0 Clay, light olive-gray (5Y5-6/2) to pale-olive 

(10Y5-6/2); thin to laminar bedding with silty partings; varvelike in top 3 in.

670.0 3.7 No core.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

CHINA DRILL HOLE MD-1-Continued

25

Depth Unit

(feet) thickness Description 

________(feet)_________________________

673.3 3.3 Clay, yellowish-gray (5Y6/2) to pale-olive (10Y6/2);

laminar bedding with silty partings. 

674.9 1.6 Sand, medium, clayey, yellowish-gray (5Y6/2), bottom

1. 2 ft still damp and darker; very faint thin bedding. 

680. 0 5. 1 No core.

680. 4 . 4 Clay, light olive -gray (5Y4/2), still damp; massive. 

686. 2 5. 8 Clay, slightly silty, pale -olive (10Y6/2) to yellowishgray (5Y6/2); laminar bedding; generally fissile. At

686. 1 ft there is a 1-mm bed of very light gray (N8)

glass* with a refractive index of about 1. 49. 

686.8 .6 Clay, silty, pale-olive (10Y6/2) to yellowish-gray

(5Y5-6/2); laminar bedding. Ostracodes(?) noted. 

690. 0 -3. 2 No core. 

691.0 1.0 Clay, silty, light olive-gray (5Y5-6/2) to pale-olive

(10Y5-6/2), still damp; laminar bedding. Contains

many laminae of yellowish-gray (5Y8/1) calcite*. 

692.7 1.7 Clay, silty, yeUowish-gray (5Y7/2) to pale-olive

(10Y6/2); thiii to laminar bedding; fine chunky fracture. Grades into unit below. 

694. 0 1.3 Sand, medium, clayey, pale -olive (10Y6/2); very faint

thiii bedding. 

700.0 6.0 No core.

SEARLES DRILL HOLE L-W, L-W-D

ISearles L-W, surface to 150 feet, was drilled by the American Potash & Chemical Corp. and is published 

with their permission; it was logged by F. J. Dluzak and M. Flaherty and has been modified by G. I. Smith. 

Searles L-W-D extends from the bottom of Searles L-W to 875 feet; 47 percent of the core was recovered.]

Depth n 4 + A (feet) thickness Description 

(feet)

2.0 2.0 Halite, granular and cubic, in light-green mud. 

3.0 1.0 No core.

5.0 2.0 Halite, granular and cubic, in light-green mud. 

6.8 1.8 Halite, cubic and granular, in greenish mud. 

7.6 .8 No core.

8.8 1.2 Halite, cubic and granular, in greenish mud. 

11.4 2.6 Mud, light-green, and granular and cubic halite. Equal

proportions of halite and mud. 

12.7 1.3 Halite, granular and cubic, unconsolidated, in equal proportions.

13.4 .7 Mud, soft, green. Halite crystals throughout. 

14.7 1.3 Mud, green, uncompacted. Halite crystals throughout. 

15.8 1.1 Mud, green, uncompacted. Large elongated halite crystals of both cubic and octahedral shapes. 

16. 1 .3 No core. 

17.4 1.3 Mud, green, uncompacted. Large elongated halite crystals. 

17.8 .4 No core.

18. 8 1.0 Halite, loose, in a matrix of green mud.

19. 1 .3 Halite, cubic, octahedral, and granular.

19. 4 .3 Halite, uncompacted. Some greenish mud.

20.2 .8 Halite?, uncompacted octahedrons and cubes in green

mud.

21.7 1. 5 Halite, octahedrons and some cubes, in green mud. 

22. 0 .3 Halite and green mud.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D Continued

/,T . \ thickness Description

(feet) (feet) __________________________________________

23. 4 1.4 Halite, loose. Green mud and orange hanksite colored

by algae in bottom 3 in. 

24.2 .8 Hanksite, . orange, algae-stained. Large halite crystals

in clusters, a little mud, some borax. 

25.2 1.0 Hanksite, orange, algae- stained, crystals of different

sizes. Large halite crystals; some green mud. 

27.4 2.2 Hanksite crystals, algae-stained. Fragments of halite,

borax crystals; a little trona; green mud. 

27. 6 .2 No core. 

29.1 1.5 No core. 

29.8 .7 Halite, granular, dense crystalline laggregate. Pockets

of glaserite and borax; some gray trona and scattered

trona needles.

30. 0 .2 No core. 

30. 7 .7 Halite. 

31.2 .5 Trona, gray, in alternating seams. A little halite and

hanksite. 

31. 9 .7 Halite fragments and gray trona. Large hanksite crystals at base. 

32.3 .4 Hanksite and halite, hard. Sulfohalite scattered throughout; gray trona in cavities. 

32. 6 .3 Trona, muddy. Large crystals of hanksite and sulfohalite; some green mud. 

32.9 .3 Trona, soft. Halite. 

33.4 .5 Halite. Hanksite in lower part. 

33.6 .2 Hanksite, halite, and greenish mud. A little sulfohalite.

Hanksite crystals large. 

. 2 Hanksite and halite, hard. A little sulfohalite; greenish

mud at top and base.

33. 9 .1 Mud, greenish.

34. 4 .5 Hanksite. Green mud. Gray trona at top.

35.2 .8 Halite. Pockets of -borax and hanksite. Gray trona and

sulfohalite at top.

35, 5 . 3 Halite. A little gray trona. 

35. 8 .3 Halite and trona, soft.

.36.1 .3 Halite and trona. Some large hanksite crystals. 

36.3 .2 Halite, vuggy. Borax and halite crystals embedded in

the halite. Some gray trona and mud.

37. 0 .7 Borax. Some gray trona; a little halite. 

38.0 1.0 Borax. Some halite and trona. 

38. 3 .3 No core. 

38.7 .4 Halite and trona.

38. 8 .1 Halite and trona, uncompacted.

39. 5 .7 Halite, hard, and cream-colored trona, in alternating

seams. Pockets of glaserite; streaks of hanksite.

Uncompacted halite and trona on top. 

40.1 .6 Trona, cream-colored, and halite, in equal proportions.

Thin seams of glaserite and hanksite; a little borax. 

40. 7 .6 Halite, hard. Some gray and cream-colored trona.

Pockets of glaserite and brownish mud at the base. 

41,0 ,3 Halite. Gray trona; some glaserite.

41.8 .8 Halite, vuggy. Gray trona and some glaserite, Hanksite in top 2 in.

42. 0 .2 Trona, hard, and hanksite. Some halite and mud. 

42.6 .6 Halite, , vuggy, pure, and gray trona. A little hanksite

and mud.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

SEARLES DRILL HOLE L-W, L-W-D-Continued

Unit

/ - > thickness Description 

(feetj (feet)________________________

42.7 0.1 No core:

43.1 .4 Halite and some trona.

44.0 .9 Halite, vuggy, pure. Trona and glaserite.

44.8 .8 Halite and gray trona and glaserite. Small sulfohalite

crystals.

45.0 .2 No core.

45.2 .2 Halite, pure. Trona and glaserite. 

45.9 .7 Halite. Glaserite throughout.

46.3 .4 Halite. A thin muddy trona seam contains sulfohalite. 

Some glaserite.

46.4 .1 No core.

46.8 .4 Halite, vuggy, pure. Large amounts of trona and sulfohalite in top 2 in.; trona needles at base.

47. 6 . .8 Halite, vuggy, pure. Some glaserite and trona. 

48.3 .7 Halite and cream-colored trona. Large amounts of

glaserite. Cavities throughout.

49.4 1.1 Halite, glaserite, trona, and sulfohalite. 

49.7 .3 Halite, muddy. Some gray trona. Glaserite. 

50.3 .6 Halite. A little black mud; a few white hanksite crystals; small sulfohalite crystals. 

50.5 .2 Halite and trona and glaserite. Some hanksite; small

sulfohalite crystals. 

50.8 .3 Halite, pure. Glaserite and trona; some muddy trona

on top.

51.3 .5 Halite, hard. A little trona and hanksite. 

51.5 .2 Halite, muddy and granular. Thin mud seams contain

hanksite crystals. 

52.5 1.0 Halite, pure. Cream-colored trona. Glaserite in seams

and pockets. A few white hanksite crystals in upper

part. 

53.5 1.0 Halite, pure. Trona includes a large percentage of

glaserite. 

56.4 2.9 Halite, pure. Pockets and seams of glaserite; thin

seams of cream-colored trona. A little hanksite;

octahedral halite.

56.8 .4 Trona and halite.

57.5 .7 Trona, fine-grained. Granular halite. 

58.9 1.4 Halite, granular, and seams of halite octahedrons.

Thin seams and pockets of glaserite and trona; a little

hanksite; some black mud at the base. 

60.6 1.7 Halite, pure. Pockets of glaserite, borax, and a little

hanksite. Some trona on top. A few large cavities. 

60.8 .2 Halite, sugary. Hanksite at base. 

61.0 .2 Hanksite with glaserite, halite, and borax surrounding

the crystals. A little black mud.

61.6 .6 Glaserite, vuggy. Some soft trona and halite. 

62.0 .4 Halite, sugary. Two thin mud seams about 2 in. apart. 

62.3 .3 Halite, vuggy, and glaserite. Small irregular mud

seam. Some gray trona. 

62.5 .2 Halite. 

63.3 .8 Halite, fine-grained, granular. A large amount of gray

trona.

63.9 .6 Trona, sugary. A little halite. 

64. 5 .6 Trona and halite in almost equal proportions. 

64.6 .1 Trona, gray, and halite.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D Continued

Unit

thickness Description 

(feet)

1.2 Halite, pure; slightly porous, with 2-in. trona seams

near top; a little trona throughout. 

66.4 .6 Halite and trona.

67.4 1.0 Halite, pure. Trona. A little hanksite in top 2 in. 

67.9 .5 No core.

69.3 1.4 Trona, cream-colored. A trace of halite. 

69.7 .4 No core. 

70.3 .6 Trona, light-gray. 

70.9 .6 Trona, medium-gray. 

71.4 .5 Trona, soft. Borax and black mud. 

72.0 .6 No core. 

72.8 .8 Mud, black. Pirssonite crystals; a little trona; a few

borax crystals. 

73.8 1.0 Mud, black, and pirssonite crystals. Thin seams of

gray mud and a red organic substance. 

75.8 2.0 Mud, black. Gray seams contain tychite(?). Thin

seams of red organic material. Scattered pirssonite

crystals. 

78.7 2.9 Mud, black. Gray clay seams contain tuchite(?).

Scattered pirssonite crystals. 

82.1 3.4 Mud, black, and many small pirssonite crystals. Clay

seams contain tychite( ?) in upper half. 

82.5 .4 Mud, black. Many pirssonite crystals. 

84.5 2.0 Mud, black. Many small pirssonite crystals. A few

bluish-gray seams. 

85.0 .5 Trona, gray, vuggy. Black pirssonite mud, borax

crystals.

85.2 .2 No core. 

86.4 1.2 Trona as slightly porous fine needles. Some black mud

in cavities.

86.8 .4 No core. 

87.6 .8 Trona as loose fine needles. 

88.0 .4 Halite, vuggy. Gray trona; black pirssonite mud. 

89.7 1.7 Mud, dense, black. Laced with small diamond-shaped

pirssonite crystals.

90.5 .8 Trona, flaky and gray.

92.3 1.8 Halite. Locally coherent. Gray trona throughout. 

92.5 .2 No core, 

93.3 .8 Halite, loosely coherent. Some trona and streaks of

red organic substance. 

93.5 . 2 No core. 

94.0 .5 Trona, soft, mushy, gray. A little halite on top; core

tinged slightly red by organic substance.

94.3 .3 Mud, dense, 'black. Pirssonite crystals throughout. 

94.5 .2 No core. 

96.1 1.6 Pirssonite mud, dense, black. Laced throughout by

small diamond-Shaped pirssonite crystals. Small

patch of nahcolite.

96.5 .4 Trona, fine-grained; gray. Some mud.

96.6 .1 No core.

96.8 .2 Trona, mushy; gray. Crumbly halite.

97.5 .7 Halite, both pure and impure, mixed with gray trona.

Small f-in. mud seam near bottom. 

97.9 .4 Halite, sugary. Gray trona. Crumbly halite and trona

at bottom. 

98.1 .2 No core.
oq

CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

_______SEARLES DRILL HOLE L-W, L-W-D-Continued________

Depth Unlt

f-riL-t- 1* thickness Description

Ueet; (feet)__________________________________________

98.9 0.8 Halite, loose, crumbly. Some gray trona. Irregular

burkeite seam on bottom. 

99.1 .2 No core.

99.3 .2 Halite, porous, crumbly. Some gray trona. 

99.8 .5 Halite, hard, dirty. Bottom 2| in. is vuggy burkeite.

Gray trona in cavities. 

100.0 .2 No core.

100.7 .7 Burkeite, porous. Some halite and trona.

100.8 .1 No core.

101.0 .2 Trona as fine needles. Some halite and burkeite.

101.1 .1 No core.

101.7 .6 Trona as large needles. A-large pocket of burkeite. 

A little halite.

101.8 .1 No core.

102.0 .2 Halite, crumbly and trona. Small pocket of burkeite.

102.1 .1 No core.

102.7 . 6 Trona as needles and blades. Halite crystals;burkeite 

fragments.

102.8 .1 No core.

104.5 1.7 Halite, crumbly. Gray trona; burkeite fragments.

105.1 .6 Trona, solid, gray. Large pockets of burkeite.

105.8 .7 Halite, vuggy, granular, and crumbly. Gray trona and 

burkeite throughout.

106.4 .6 Halite, crumbly. Gray needles of trona. Large pocket of burkeite. Thin seam of borax 1 in. from base .

107.0 .6 Halite, vuggy. Irregular seam of burkeite contains a 

large cavity. Gray trona and a seam of hard halite 

at the base.

107.1 .1 No core.

107.3 .2 Mud seam, stained deep red. Large percentage of trona 

and borax crystals.

107.4 .1 No core.

107.6 .2 Halite, hard, vuggy. Trona and thin streaks of mud.

108.2 .6 Halite, hard. A large percentage of muddy trona; large 

burkeite pocket; black mud on bottom.

108.3 .1 No core.

108.6 .3 Mud seam stained red by organic substance. Large 

amount of trona; some borax. Gray clay seams 

throughout.

109.0 .4 No core.

109.4 .4 Burkeite and trona. Some trona is changing to burkeite.

110.1 .7 No core.

111.8 1.7 Mud, black, and pirssonite crystals. A few gray clay 

seams (tychite?) throughout. Small patch of nahcolite and burkeite fragments in top 4 in.

112.2 .4 No core.

113.0 .8 Trona needles. Some appears to be changing to burkeite. A few fairly large cavities (possibly thenardite).

113.2 .2 No core.

114.1 .9 Mud, dense, black. Laced throughout by pirssonite 

crystals.

114.4 .3 Trona, mushy. Trona needles. Some mud.

114.5 .1 No core. , ' I

115.3 .8 Trona, hard, vuggy. Tiny halite crystals.

115.4 .1 No core.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D-Contirtued

Depth 

(feet)

116.3

116.5

117.0

117.2

117.5

118.2 

118.3

118.9 

119.0

119.7 

119.9

120. 1

120.7 

120.8

121.5

123.6 

123.8

127.5

Unit 

thickness 

(feet)

0.9

.2

.5

.2

.3

.7

.1

.6

.1

.7 

.2

.2

.6 

.1

.7

2.1 

.2

3.7

Description

Trona, slightly porous, needles. Large amount of 

black mud. Hard irregular halite seam near base.

Mud seam, dense, black, fractured. Scattered tiny 

pirssonite crystals.

Mud, dense, black. Gray clay seams (tychite ?) throughout. Scattered pirssonite crystals.

Mud, black, mushy. Some trona embedded in mud.

Mud, black. Laced by pirssonite crystals.

Mud, dense, black. Gray clay seams (tychite?). Scattered pirssonite crystals. 

No core.

Trona, fairly porous, needles. Tiny thin seams of red 

organic substance. Hard bony trona on bottom (possibly thenardite). 

No core.

Trona, as flaky blades and needles. A little mud. 

No core.

Trona, soft, mushy. Black mud on bottom.

Mud, black. Laced by gaylussite crystals. A few gray 

clay seams (tychite?). 

No core.

Mud, dense, black. Laced by gaylussite crystals.

Mud, dense, black. Gray clay seams (northupite and 

tychite) throughout. Scattered gaylussite crystals. 

No core.

Mud, dense> black. Laced throughout by gaylussite

crystals. The bottom 30 in. has a few gray clay 

seams (tychite or northupite).

129.1 1.6 Mud, dense, black. Gray clay seams (northupite or 

tychite). Scattered gaylussite crystals.

129.5 .4 Mirabilite, solid. A little mud engrained.

131.5 2.0 Mud, dense, black. Laced by gaylussite crystals. A 

few gray clay seams (tychite or northupite),

134.7 3.2 Mud, dense, black. Gaylussite crystals. Patches of 

mirabilite in bottom 12 in. A few gray seams (tychite or northupite).

135- 5 -8 Mud, dense, black. Laced by gaylussite (or northupite).

137.9 2.4 Mud, dense, black. Laced throughout by gaylussite

crystals. A few gray clay seams. 

138.1 .2 No core.
01

CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

SEARLES DRILL HOLE L-W, L-W-D-Continued_________

Depth Unit

/- .\ thickness Description

(feet) (feet)__________________________________________

138.8 .0.7 Mud, black. Gray clay seams, blue clay seams, and 

thin seams of red organic material. Scattered small 

gaylussite crystals.

139.7 .9 Mud, black. Gray and blue clay seams. Scattered gaylussite crystals. 

139.9 .2 No core.

141.9 2.0 Mud, black. Tiny gaylussite crystals scattered throughout. Gray and blue clay seams; thin seams of red 

organic material. A twig(?) embedded in top inch.

142.5 .6 Clay, greenish-gray. Tiny white particles embedded 

in the clay. Clay has large percentage of sand.

144.3 1.8 Clay, green-gray. Middle 6 in. very gritty; probably 

contains tiny crystals ofnorthupite or tychite. Large 

percentage of sand.

145.4 1.1 Mud, black. Blue-gray seams of volcanic ash( ?). Scattered tiny gaylussite crystals. Patches of greenishgray clay.

147.7 2.3 Mud, black. Gray clay seams, gaylussite sand. Core 

has 3 distinct fractures from top down 7 .in.

148.9 1.2 Mud, black. Gray clay seams of northupite(?). High 

percentage of sand. Mud appears to be a gaylussite 

sand.

149.4 .5 Mud, black. Gray clay seams of northupite(?). Some 

sand.

150.0 .6 Mud, black. Gray clay seams of northupite(?). Some 

sand. Gaylussite crystals scattered in top section 

but dense in bottom. Patches of mirabilite in bottom 

3 in.

151.7 1.7 Clay, with about 25 percent gaylussite. Crystal sizes 

range from 1 to 3 mm. Dusky yellow green (5GY4-5/2). 

Massive.

152.6 .9 Silt; mottled colors, greenish gray (5GY6/1) and yellow 

ish gray (5Y6/2). Less than 5 percent of material 

gaylussite crystals; average size about 3 mm. Massive. At base there is a 1-in. bed of fine-grained 

trona.

153.3 .7 Clay, top 2 in. about 50 percent gaylussite with crystals 

about 10 mm long. Grades downward into clay containing about 10 percent gaylussite crystals. Dark 

greenish gray (5GY4/1). Massive.

156.9 3.6 Clay, with about 50 percent gaylussite crystals; average 

size 2 mm. Color ranges from dark greenish gray 

(5GY4/1) to grayish olive (10Y4/2) to grayish yellow 

green (5GY6/2). Mostly massive, local indistinct 

bedding.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D-Continued

Depth Unit

/- 4.\ thickness Description

(feet) (feet) __________________________________________

157.1 0.2 Clay; color ranges from greenish yellow (10Y6/4) to 

pale olive (10Y6/2) to grayish olive (10Y3-4/2) to 

light greenish gray (5GY9/1). Laminar bedding defined by color changes.

157. 3 . 2 Clay, similar to clay at depth of 156. 9 ft.

160. 0 2. 7 No core.

163.6 3.6 Gravel, crystal, about 70 percent gaylussite, a little 

thenardite, clay, and probably other minerals. Average crystal size about 2 mm. Grayish yellow green 

(5GY8/2). Poorly consolidated; may be cuttings, not 

core.

169.2 5.6 Clay, with an average of 30 percent gaylussite crystals; 

crystal sizes up to 5 mm, average 2 mm; greenish 

gray (5GY6/1). Thick bedding, very faint.

170.0 .8 No core.

170. 8 . 8 Clay, similar to clay at depth of 169. 2 ft. Crystal sizes 

up to about 20 mm; average about 5 mm.

176.7 5.9 Clay, with 30 to 50 percent gaylussite crystals. Crystal 

sizes range from 2 to 10 mm, average 5 mm. Colors 

range from pale olive (10Y6/2) to grayish yellow 

(5Y7/4) to yellowish gray (5Y7/2). Massive; crystals appear randomly oriented.

177. 4 . 7 Gravel, crystal, about 60 percent crystals of gaylussite 

in a clay matrix. Crystal sizes range from 1 to 5 mm, 

average about 3mm. Pale olive (10Y7/2). Poorly 

consolidated.

177. 7 . 3 Clay, with about 30 percent gaylussite crystals. Crystal sizes range from 4 to 20 mm, average about 10 mm. 

Light olive gray (5Y6/2). Massive.

179.7 2.0 Gravel, crystal, about 75 percent gaylussite crystals in 

a clay matrix. Crystal sizes range from 5 to 20mm, 

average about 12 mm. Li ght olive gra.y (5Y5/2). Massive; crystals appear randomly oriented.

180.0 .3 No core.

180. 7 . 7 Clay, with an average of about 25 percent gaylussite

crystals. Crystal sizes range from 2 to 12 mm,

average about6mm. Lightolive gray (5Y6/2). Massive, but crystals are locally concentrated.

181.6 .9 Sand, crystal, about 70 percent gaylussite crystals in 

a clay matrix. .Average size is very coarse sand; 

contains a single crystal about 25 mm long. Light 

olive gray (5Y5/2). Poorly consolidated.

182.6 1.0 Gravel, crystal, about 75 percent gaylussite crystals 

in a clay matrix. Crystal sizes range from 4 mm to 

20 mm, average about 10 mm. Light olhje gray 

(5Y5/2). Massive.

185.6 3.0 Gravel, crystal, average about 70 percent gaylussite 

crystals in a clay matrix. Crystals range from sand 

size to 15 mm, average about 4 mm. Mottled colors; 

predominantly light olive gray (5Y5/2); laminae of 

white (N9). Unit has laminar bedding, which is more 

pronounced at the base. Dolomite* noted in small 

quantities.

190. 0 4. 4 No core.
OQ

CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

SEARLES DRILL HOLE L-W, L-W-D~Continued

Depth Unit

ffe t^ thickness Description 

________(feet)__________________________________________

190.7 0.7 Clay, with about 50 percent gaylussite crystals. Crystal sizes range from 1 to 7 mm, average about 2 mm. 

Mottled coloring, predominantly pale olive (10Y6/2). 

Massive. Several nodules of burkeite* noted, approximately 5 mm thick.

190.9 .2 Silt, with thin layers of gaylussite crystals. Gaylussite 

crystals up to 2 mm in size. Silt may be very fine 

crystals and fragments of finely crystallized gaylussite. Pale greenish yellow (10Y7/2). Local thin 

bedding.

191.3 .4 Gravel, crystal, similar to crystal gravel at depth of 

182.6 ft.

192.7 1.4 Clay, containing very fine grained gaylussite*. Light 

olive gray (5Y6/1-2); one bed of olive gray (5Y3/2). 

Laminar bedding defined by color changes.

200.0 7.3 . No core.

203.8 3.8 Gravel, crystal, similar to crystal gravel at depth of 

182.6 ft. May be cuttings, not core.

204.2 .4 Clay, with about 50 percent gaylussite crystals. Sizes 

range from 1 to 10 mm; average about 4 mm. Colors 

mottled; grayish olive (10Y4/2) and dusky yellow 

(5Y6/4). Faint thin bedding defined by color changes.

210.0 5.8 No core.

211.9 1.9 Gravel, crystal, similar to crystal gravel at depth of 

182.6 ft.

215.0 3.1 No core.

216.0 1.0 Gravel, crystal, about 75 percent gaylussite crystals 

in a clay matrix. Sizes range from 1 to 8 mm, average about 3 mm. Pale olive (10Y6/2). Poorly consolidated.

217.0 1.0 Silt, with about 30 percent gaylussite crystals. Average 

crystal size less than 1 rnm. Dusky yellow (5Y5/4). 

Massive in upper part grading to laminar bedding in 

lower part. At 216.5 ft there is a 6-in. bed of nahcolite*.

220.7 3.7 Gravel, crystal, averages about 70 percent gaylussite 

crystals in a clay matrix. Crystal sizes range up to 

about 8 mm; average size about 5 mm at top, diminishing to about 1 mm at bottom. Colors range from 

olive gray(5Y3/2) to grayish olive (10Y4/2). Generally well bedded but locally massive in lower part. 

Upper part contains 1 mm aggregates of parallel gaylussite crystals alternating with 2 mm beds of clay. 

Contains a few randomly oriented gaylussite crystals. 

One-inch beds of fine-grained nahcolite* occur at 

219. 3, 220.1, and 220. 6 ft.

225.0 4.3 No core.

227.7 2.7 Sand, crystal, similar to crystal sand at depth of 

181.6 ft. May be cuttings, not core.

228.2 .5 Nahcolite*, fine-grained. At 227.8 ft there is a 1-in. 

bed of crystal silt containing about 90 percent siltsized gaylussite crystals in a clay matrix. Dusky 

yellow (5Y5/4). Massive.

235.0 6.8 No core.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D-Continued

Depth Unit

(feet) thickness Description

(feet) __________________________________________

236.8 1.8 Clay, with about 10 percent gaylussite crystals. Crystal 

sizes range from 1 to 3 mm. Mottled colors; from 

dusky yellow green (5GY5/2) to grayish olive (10Y4/2). 

Poorly consolidated. May be cuttings, not core.

239.0 2.2 Sand, crystal, similar to crystal sand at depth of 181. 6 ft. 

May be cuttings, not core.

239.9 0.9 Clay, with about 50 percent gaylussite crystals. Crystal sizes range from 0. 5 to 3 mm, average about 

2 mm. Color ranges from light olive gray (5Y5/2) 

to light olive brown (5Y5/4). Massive; pseudobedding 

caused by local concentrations of crystals. Bottom 

4 in. is fine- grained nahcolite* with partings of clay.

245. 0 5. 1 No core.

245.7 .7 Sand, crystal, similar to crystal sand at depth of 181. 6 ft. 

May be cuttings, not core.

247.5 1.8 Trona*, crystalline, in "jackstraw" aggregates of acicular crystals. Lengths of crystals up to 5 mm. Massive. Several small crystals of tychite* noted at 

246. 5 ft.

248. 2 . 7 Sand, crystal, average of 50 to 60 percent gaylussite 

crystals in a clay matrix. Crystal sizes range from 

1 to 3 mm. Yellowish gray (5Y7/2). Massive.

248. 5 . 3 Sand, crystal, principally trona* crystals, about 1 mm 

in size, in a fine white matrix. Associated with the 

trona is a faintly anisotropic spherulitic substance 

with an average refractive index of about 1. 53; it 

gives a moderately strong positive test for boron and 

may be searlesite*. Laminar bedding.

255.0 6.5 No core.

256.5 1.5 Sand, crystal, generally 80 to 90 percent gaylussite 

crystals and a little clay. Crystal sizes range from 

0.5 to 2.0 mm. Pale olive (10Y5/2). Poorly consolidated. May be cuttings, not core.

257.4 .9 Sand; crystal, similar to crystal sand at depth of 

181. 6 ft. May be cuttings, not core.

258. 0 . 6 Gravel, crystal, with about 50 to 60 percent gaylussite 

crystals in a clay matrix. Crystal sizes range from 

1 to 12 mm, average 5 mm. Olive gray (5Y3/2). 

Local laminar bedding. At the bottom there is al-in. 

bed of fine-grained trona*.

265. 0 7. 0 No core.

268.2 3.2 Sand, crystal, similar to crystal sand at depth of 256.5 ft.

May be cuttings, not core. 

269. 0 ' .8 Trona*, crystalline; coarse-grained crystals in a finegrained matrix. Massive. 

275.0 6.0 No core.

281.0 6.0 Trona*, crystalline; clay impurities range up to about 

70 percent. Crystal sizes range up to about 20 mm. 

Orientation of crystals is generally random, locally 

radiating. Within this unit, from 275. 8 to 276. 3 ft, 

is a layer of clay containing about 20 percent gaylussite crystals which average about 3 mm in size. 

Colors of the clay range from light olive gray (5Y5/2) 

to grayish olive (10Y4/2). Massive.
gc 

CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

_______SEARLES DRILL HOLE L-W, L-W-D-Continued_________

Depth Unit

(feet) thickness Description

(feet)___________________________________

285.0 4.0 No core.

287.5 2.5 Sand, crystal, similar to crystal sand at depth of 

256.5 ft; contains small amounts of trona. May be 

cuttings, not core.

290.6 3.1 Clay, containing an average of about 50 percent crystals 

of gaylussite, pirssonite, and northupite*. Crystal 

sizes range from fine sand to about 3 mm; average 

is fine sand in upper part, coarse sand in lower part. 

Within this unit from 288.4 to 289.6 ft is a layer of 

fine to coarsely crystalline trona with clay impurites. 

Color of the clayey portion is grayish yellow (5Y7/4). 

Massive.

295.0 4.4 No core.

295.7 .7 Gravel, crystal, containing about 50 percent gaylussite crystals in a clay matrix. Crystal sizes range 

from 1 to 4 mm, average about 2 mm. Pale olive 

(10Y6/2). Poorly consolidated. May be cuttings, 

not core.

298.2 2.5 Gravel, crystal, about 65 percent crystals of gaylussite and pirssonite, in an average ratio of about 5 to 

1, in a clay matrix. Crystal sizes range from about 

2 to 20 mm, average about 10 mm. Color light olive 

gray (5Y6/2) to dusky yellow (5Y6/4). Crude bedding 

in clay at bottom. At 297.5 ft is a 1-in. bed of crystalline trona with a little clay.

305.0 6.8 No core.

306.1 1.1 Gravel, crystal, mostly gaylussite with a little trona, 

in a clay matrix. C rystal sizes range from 2 to 5 mm, 

average about 3 mm. Dark greenish gray (5GY4/1). 

Poorly consolidated.

307.9 1.8 Silt, crystal, about 75 percent crystals, mainly pirssonite, a little northupite* and a trace of gaylussite* 

in a clay matrix. Majority of crystals are silt size, 

but sizes range up to 10 mm. Yellowish gray (5Y6/2). 

Massive.

310.7 2.8 Badly fractured core containing fragments of trona, 

halite, and clay in the following sequences: 307.9 to 

308.3 ft, crystalline trona; 308.3 to 308.8 ft, clay 

and trona; 308.8 to 309.3 ft, halite and clay; 309.3 to 

309.4 ft, clay; 309.4 to 310. 1 ft, coarsely crystalline trona; 310.1 to 310.3 ft, clay and halite crystals; 

310.3 to 310.7 ft, halite. Average color of the clay 

is yellowish gray (6Y6/2).

315.0 4.3 No core.

317.8 2.8 Halite*, coarsely crystalline; fine-grained trona* and 

nahcolite* estimated microscopically at 10 percent of 

total material. Halite crystal sizes up to 20 mm, 

average 8 mm. Within this unit are 2-in. clay beds 

at 316.7 and 317.2 ft. Salts are massive.

318.5 .7 No core.

319.8 1.3 Halite, with a little trona* and gaylussite*. Crystal 

sizes range from 1 to 8 mm, average about 3 mm. 

Overall color greenish gray (5GY5/1). Poorly consolidated. May be cuttings, not core.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D-Continued

Unit

thickness Description 

(feet)

324. 0 4. 2 Halite, in crystalline aggregates; crystal sizes up to 

about 30 mm, average about 6 mm. Contains many 

irregular clay inclusions. Core badly shattered; no 

bedding visible.

325.0 1.0 No core.

327. 2 2. 2 Halite*, local clay impurities in top foot; remainder is 

relatively pure. Crystal sizes up to about 45 mm, 

average 8 mm. Massive.

333. 0 5. 8 No core.

333. 5 . 5 Trona, finely crystalline; a little clay, halite, and probably nahcolite. Crystal sizes up to about 2 mm. 

Massive.

343.0 9.5 No core.

345. 3 2. 3 Trona, upper part about 40 percent clay, a little clay 

in lower part. Crystal sizes up to 10 mm, average 

about 8 mm. Clay is light olive gray (5Y5-6/2). 

Massive; crystals randomly oriented.

348.0 2.7 No core.

349. 9 1,9 Trona* and halite, crystalline, grading downward into

i trona and a little nahcolite*. Coarse grained at top

with crystal sizes up to 25 mm; finer grained at bottom, sizes range from 1 to 5 mm. Massive; crystals

randomly oriented.

353.0 3.1 No core.

355. 0 2. 0 Sand, crystal, about 90 percent crystals of trona, gaylussite, and halite. Sizes range from 0. 5 to 2 mm.

Pale olive (10Y5/2). Poorly consolidated. May be 

cuttings, not core,

355. 5 . 5 Clay, light greenish-gray (5GY8/1) and pale greenishyellow (10Y8/2). Laminar bedding defined by color 

changes. Contains several crystals of northupite* 

about 10 mm in size.

363.0 7.5 JSTo core.

363 - 6 6 " Sand, crystal, similar to crystal sand at depth of 

355. 0 ft. Probably cuttings, not core.

363. 8 . 2 Trona, crystal sizes up to 20 mm. Massive; crystals

form radial aggregates. 

368. 0 4. 2 No core.

368.7 .7 Sand, crystal, about 90 percent crystals which are 

mostly gaylussite, with smaller amounts of trona and 

halite, and traces of sulfohalite*. Very well sorted, 

approximates coarse sand. Pale olive (10Y6/2).

Poorly consolidated. This could be cuttings but is

probably core. 

368.9 .2 Trona. Crystal sizes up to 15mm, average 10 mm,

Massive; crystals form radial aggregates. 

378. 0 9. 1 No core.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

.SEARLES DRILL HOLE L-W, L-W-D Continued

/_ . \ thickness Description (feet) (feet)

382.4 4.4 Trona*. Crystal sizes up to 10 mm, average about 

5mm. Crystals are randomly oriented; locally vuggy; 

entire section is well consolidated, but porous. Unit 

contains 5 zones of clay as follows: at 378. 0 ft, a 

1-in. bed of clay containing about 10 percent pirssonite and a little trona; at 378.9 ft a 1-in. bed of 

trona containing about 30 percent clay; at 379. 7 ft, 

a ^-in. bed of clay containing about 20 percent trona; 

at 380.3 ft, a 5-in. bed of clay containing about 

10 percent crystals of pirssonite, averaging about 

1 mm in size, and a little trona; at 382. 0 ft a 2-in. 

bed of clay containing about 10 percent crystals of 

pirssonite. The thicker beds of clay are yellowish 

gray (5Y6/2) and massive.

388. 0 5. 6 No core.

389.9 1.9 Trona* and halite* intergrown. Either mineral may 

predominate locally, but the average is 50 percent 

halite and 50 percent trona. Crystal sizes up to 

10 mm, average about 5 mm. Porosity is higher in 

the layers of trona. Massive.

390.9 1.0 Clay, with about 20 percent gaylussite and pirssonite 

and a small amount of trona. Crystal sizes up to 

3 mm, average about 2 mm. Colors are mottled and 

range from dark greenish gray (5GY4/1) to grayish 

yellow (5Y7/4). Massive.

393. 0 2. 1 No core.

396. 8 3.8 Halite*, with local concentrations of trona. At 393. 5 

and 396. 5 ft are 3-in. layers of trona with a little 

halite; remainder of section is predominantly halite. 

Crystal sizes up to 10 mm, average about 4 mm. 

Halite contains local inclusions of clay. Massive.

397.2 .4 Halite and clay, with a little trona and pirssonite. Halite and trona crystals up to 8 mm in stee, average 

about 3 mm; pirssonite crystals are sand sized. 

Greenish gray (5GY5/1). Massive.

398. 0 . 8 No core.

399. 0 1.0 Halite and a little clay. Crystal sizes up to 10 mm, 

average 5 mm. Maximum percentage of clay in lower 

half is about 10 percent. Massive.

400. 0 1.0 Clay, with about 5 percent crystals of trona and halite 

in local concentrations and very small amounts of 

small unidentifiable crystals. Pale greenish yellow 

(10Y7/2). Massive.

408. 0 8. 0 No core.

409. 1 1.1 Gravel, crystal. Halite in a clay matrix. Crystal 

sizes up to 20 mm, average about 8 mm. Yellowish 

gray (5Y7/2). Poorly consolidated. Probably cuttings, not core.

413.0 3.9 No core.

416. 4 3. 4 Halite and a little clay. At 413. 7 ft there is a 2-in. 

layer of clay containing pirssonite crystals. Entire 

unit badly shattered during drilling so that core consists of nothing but chips.
38 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D-Continued.

/-. . \ thickness Description

* '____(feet)__________________________________________

417.0 0.6- No core.

417.8 .8 Gravel, crystal, predominantly halite and trona. Crystal sizes range from 1 to 7 mm, average about 3 mm. 

Probably cuttings, not core.

419.2 1.4 Halite. Crystal sizes up to 15 mm, average about 5 mm. 

Local clay impurities.

419.7 .5 Trona*; very fine grained; contains small masses of 

halite* and burkeite*. Light yellowish gray (5Y9/1). 

Very compact and pure; faintbedding2 to 3 mm thick.

420.0 .3 No core;

422.8 2.8 Halite*, with a little trona and nahcolite*. Crystal 

sizes up to 20 mm, average about 6 mm. Bottom inch 

contains halite* and pirssonite* in a very fine grained 

aggregate. This section badly shattered during 

drilling.

430.0 7.2 No core.

433. 7 3. 7 Gravel, crystal, similar to crystal gravel at depth of 

417.8 ft. One small fragment of trona noted.

440.0 6.3 No core.

442.8 2.8 Gravel, crystal, similar to crystal gravel at depth of 

417.8 ft.

443.6 8 Halite*, crystal sizes up to 15 mm, average about 

7 mm. Top 3 in. contains interbe.dded trona and 

clay. Trona is very fine grained. Clay is dark 

greenish gray (5GY4/1). Halite is massive.

450.0 6.4 No core.

452.7 2.7 Assortment of core fragments containing trona, halite, 

pirssonite, and clay. Top inch consists of interlocking plates of trona up to 20 mm long; the interstices 

are filled with cryptocrystalline trona*. A few octahedrons of northupite* were also noted.

460.0 7.3 No core.

461.2 1.2 Clay grading down to crystal gravel. Contains halite, 

trona, and. a little pirssonite. Crystal sizes range 

from 1 to 5 mm, average 3 mm. Yellowish gray 

(5Y7/2). Poorly consolidated.

464.0 2.8 Halite, with a little trona. Crystal sizes up to 15 mm, 

average about 4 mm. Massive.

465.3 1.3 Trona* with halite. Halite content grades downward 

from 50 to 5 percent. Lower part contains small 

patches of burkeite*; at the base there is a thin bed 

of clay. Trona is fine grained with saccharoidai 

texture. Faint bedding.

470. o 4.7 NO core.

472i 6 2,6 Halite*, with local clay impurities. Crystal sizes up 

to 20 mm, average abOUt 4 mm( Core badly broken 

during drilling.

480.0 7.4 No core.

482.3 2.3 Clay, with about 80 percent halite at top grading to about 

lOpSrCSflt halite at bottom. Halite crystal sizes up

to about 8 mm, average about 3 mm. CfllOK C10ttl6(3j 

range from yellowish gray (5Y7/2) to dusky yellow 

(5Y7/4). Massive. Top 4 in. poorly consolidated; 

may be cuttings, not core. 

490.0 7.7 No core.
 3Q

CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

_______SEARLES DRILL HOLE L-W, L-W-D-Continued________ 

_ 

(feet) thickness Description 

________(feet)__________________________________________

492.2 2.2 Halite. Crystal sizes up to 25 mm, average about 6 mm. 

Core badly shattered and unit contains many cuttings.

493.6 X. 4 Sand, crystal, very fine; consists mainly of pirssonite* 

and northupite*; variable amounts of clay. Pale olive 

(10Y6/2). Massive. Bottom 4 in. contains mediumgrained trona and a little halite.

500.0 6.4 No core.

504.0 4.0 Halite, crystal sizes up to 10 mm, average about 3 mm. 

At 500.3 and 501.1 ft there are 1-in. beds of clay 

containing about 20 percent pirssonite crystals averaging about % mm in size. Clay is mottled; average 

color about light olive -gray (5Y6/1). Core badly 

shattered and unit contains many cuttings.

504.6 .6 Trona*, saccharoidal, contains fragments of sulfohalite* 

and halite* up to about 3 mm in size. White (N9). 

Very faint bedding, 1 to 3 mm thick.

510.0 5.4 No core.

512.0 2.0 Gravel, crystal, consisting of fragments of halite, 

trona, a little gaylussite, and about 10 percent clay. 

Fragments range from 1 to 4 mm, average about 2 mm 

in size. Probably cuttings, not core.

515.2 3.2 Clay, with about 5 percent pirssonite. Crystals 1 to 

2 mm in size. Colors mottled, include pale olive 

(10Y6-7/2), dusky yellow (5Y7/4), and yellowish gray 

(5Y7/2). Very faint bedding about 2 to 5 mm thick 

defined by color changes.

520.0 4.8 No core.

520.4 .4 Clay, with about 20 percent crystals of halite and pirssonite. Crystal sizes up to about 8 mm, average 

about 5 mm. Yellowish gray (5Y7/2). Massive.

522.1 1.7 Halite, with about 30 percent clay. Crystal sizes up to 

about 25 mm, average about 6 mm. Clay is yellowish 

gray (5Y7/2). Massive. Core is badly shattered, 

and unit-contains many cuttings.

524.7 2.6 Clay, with about 15 percent crystals of halite and pirssonite*, 1 to 2 mm in size. A few small veins of 

halite noted about 1 mm thick and 15 to 20 mm long; 

both crystals and veins are randomly oriented. Pale 

olive (10Y7/2). Massive.

530.0 5.3 No core.

531.0 1.0 Clay, with about 15 percent pirssonite crystals up to 

4 mm and averaging about \ mm in size. Pale greenish yellow (10Y8/2). Top 3 in. poorly consolidated; 

probably cuttings. Massive.

531.6 .6 Siltstone; about 70 percent quartz*, orthoclase*, plagioclase*, and hornblende*, plus about 30 percent 

pirssonite*, a little halite*, and clay. The rock 

contains many pirssonite casts up to about \ mm in 

size which are coated with a drusy mineral. It also 

contains veins of halite up to about 4 mm thick and 

12 mm long. Dark gray (N3). Massive, compact, 

and very hard.

535.4 3.8 Clay, with about 10 to 15 percent pirssonite crystals 

up to 3 mm and averaging about \ mm in size. Pale 

olive (10Y6-7/2) with a few mottlings of light brown 

(5YR6/6). Massive.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D- Continued

Depth Unit

/ . \ thickness Description

(feet) (feet) __________________________________________

536.0 0.6 Halite crystals, with about 5 percent clay. Crystals up 

to 10 mm, average about 5 mm in size. Clay is yellowish gray (5Y7/2). Massive.

540. 0 4. 0 No core.

545. 0 5. 0 Halite and clay, interbedded. Halite crystal sizes up 

to 10 mm, average about 4 mm. Clay contains about 

25 percent pirssonite* and a trace of gaylussite*, 

and occurs as 1-in. beds at the following depths: 

540. 1, 540. 6, 540. 9, 542. 7, 543. 5, and 544. 4 ft. 

Clay is yellowish gray (5Y7/2). At 541. 6 ft thenardite* was noted. Core was badly shattered during 

drilling, and unit contains many cuttings.

550. 0 5. 0 No core.

551. 5 1. 5 Halite. Crystal sizes up to 20 mm, average about 

3 mm. Core badly shattered during drilling.

553.2 1. 7 Halite, with a little trona. Crystal sizes up to 8 mm, 

average about 1 mm. Ratio of halite to trona is about 

10 to 1. Core badly crushed during drilling. Bottom 

2 in. up to 10 percent clay.

553. 8 . 6 Halite* and trona* in a ratio of about 10 to 1. Crystal 

sizes up to 10 mm, average about 5 mm. Massive.

554. 4 . 6 Gravel, crystal, about 60 percent pirssonite crystals 

in a clay matrix. Crystal sizes up to 8 mm, average about 3 mm. Pale olive (10Y5/2). Poorly consolidated.

560. 0 5. 6 No core.

563.4 3.4 Halite and trona*, interbedded. Small amounts of 

thenardite*. Halite crystals up to 4 mm, average 

about 2 mm; trona crystals are generally fine grained. Core was badly shattered during drilling.

564. 2 . 8 Trona and halite, similar to unit above but not shattered 

during drilling. Massive.

570. 0 5. 8 No core.

571.2 1.2 Halite; little thenardite* and pirssonite*. Halite crystal sizes up to 8 mm, average about 1 mm. Core 

badly shattered during drilling.

574. 7 3. 5 Halite* and trona, interbedded. Crystal sizes up to 

5 mm (isolated exceptions up to 20 mm), average 

about 2 mm. Ratio of halite to trona is about 20 to 1. 

Vague horizontal banding caused by slight clay impurities.

575. 1 . 4 Sand, crystal, coarse, about 70 percent pirssonite in 

a clay matrix. Clay is dusky yellow green (5GY5/2). 

Massive.

58O. O 4. 9 No core.

584.3 4.3 Halite; a little trona*, thenardite*, and a single crystal

Of SUlfohalite*: bottom 4 in. is Dure trona. Halite 

crystals up to 8 mm, average about 3 mm in size. 

Massive.

590.0 5,7" NO core,

590. 6 . 6 Halite. Crystal sizes up to 3 mm; average abOUt 2 BUD.,

Crystals show preferential orientation toward horizontal. Bottom \ in. of this section is trona; crystals up to 8 mm long, average about 5 mm. Contact 

with halite is sharp.
41 CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

3EARLES DRILL HOLE L-W, L-W-D-Continued

Unit

/ - .\ thickness Description 

lfeetj (feet)__________________________________________

591.3 0.7 Sand, crystal, about 60 percent pirssonite crystals in 

a clay matrix. Crystal sizes up to 3 mm, average 

about 1 mm.

597.6 6.3 Trona*, with horizontal bands of clay. Crystals range 

up to 5 mm long, average about 3 mm, and are randomly oriented. Bands of clay, medium dark gray 

(N4), form bedding within this unit. Bands range 

from laminar up to 5 in. thick and are more abundant 

in the lower half of the unit. At 593.7 ft there is a 

4-in. bed of crystal sand consisting of about 60 percent pirssonite* crystals in a clay matrix; crystal 

sizes up to 2 mm, average about 1 mm.

600.0 2.4 Gravel, crystal, about 60 percent pirssonite crystals 

in a clay matrix. Crystal sizes up to 4 mm, average 

about 3 mm. Colors range from moderate greenish 

yellow (10Y7/4) to dusky yellow (5Y6/4). Poor bedding, thin to laminar, defined by orientation of crystals in some parts and by color changes within the 

clay in other parts.

605.8 5.8 Gravel, crystal, about 90 percent crystals of halite, 

pirssonite, and trona in a clay matrix. Crystal sizes 

up to 4 mm, average about 3 mm. May be cuttings, 

not core.

607.1 1.3 Trona, with about 15 percent clay. Crystals up to 15 mm 

long, average about 10 mm. Crystals are generally 

in radial aggregates. Massive; contains many cuttings.

610.0 2.9 No core.

613.9 3.9 Sand, crystal; fragments of pirssonite, halite, and 

possibly trona and gaylussite. Fragment sizes up to 

2mm, average less than 1 mm. Pale olive (10Y6/2). 

Poorly consolidated. Probably cuttings, not core.

615.5 1.6 Clay, with about 10 percent pirssonite and a few pods 

of halite. Crystal sizes up to 2 mm, average about 

1 mm. Dusky yellow (5Y5/4). Core badly shattered 

during drilling. Contains many cuttings.

620.0 4.5 No core.

621.4 1.4 Gravel, crystal; fragments of halite, pirssonite, and 

trona in about 10 percent clay. Fragment sizes up 

to 30 mm, average about 5 mm. Poorly consolidated. 

Probably cuttings, not core.

623.9 2.5 Clay and pirssonite; top third is about 30 percent pirssonite* with crystals ranging up to 5 mm but averaging 3 mm in size; bottom two-thirds is about 2 percent pirssonite with crystals ranging up to 10 mm 

but averaging less than 1 mm in size. Light olive 

(10Y5/4) to pale greenish yellow (10Y8/2). Unit has 

bedding, defined partly by beds of crystals and partly 

by fluctuations in color of clay, ranging in thickness 

from about 3 mm in upper part to laminar in the lower 

part. Laminar bedding shows graded structures under 

the microscope.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D-Continued

D th /_ .\ thickness Description 

____________________________________________________ 629.75.8 Clay to silt, generally well-sorted, yellowish-gray 

(5Y7/2) to pale-olive (10Y6/2), generally massive. 

Notable variations are as follows: at 625.0ft, a 2 in. 

bed that contains about 10 percent halite*; at 627.7ft, 

a 5-in. bed of very fine clay that contains subhorizontal veinlets of white clay (N9) and a few crystals 

of pirssonite; at 628.4 ft, a 1-in. bed of silt consisting of fine sand-sized clay*-coated octahedrons that 

contain submicroscopic fragments of an evaporitemineral* that may be calcite.

630.0 0.3 No core.

635.8 5.8 Clay*; contains pirssonite* cement which ranges from 

about 70 percent in the upper part to about 20 percent 

of the material in the lower part. Small 1 mm veins 

of pirssonite* cut diagonally through the clay. Light 

greenish gray (5GY7/1) in the upper part, yellowish 

gray (5Y7/2) in the middle part, and grayish yellow 

(5Y7/4) in the lower part. No bedding visible; unit 

is extremely well indurated.

639.2 3.4 Clay, with about 5 percent pirssonite* in the form of 

randomly oriented veins 1 mm wide, plus a few crystals. YeUowish gray (5Y7/2) to pale olive (10Y7/2). 

Contains many small disc-shaped specks of olive 

gray (5Y3/2) measuring up to about 1 mm; origin and 

character unidentified. Massive.

640.0 .8 Clay, with about 50 percent crystals, locally ranging 

from 30 to 70 percent. Sizes up to about 3 mm, average about 1 mm. Crystals in the upper part of the 

unit are all nahcolite*; in the lower part of the unit 

pirssonite may also be present. Yellowish gray 

(5Y7/2). Massive.

640.3 .3 Clay, with about 20 percent pirssonite*, crystal sizes

up to 6 mm, average about 3 mm. Yellowish gray 

(5Y7/2) and dusky yellow (5Y7/4). Massive.

650.0 9.7 Halite*. Crystal sizes up to 30 mm, average about 

5 mm. Top fOOt Contains a lew clay impurities as 

inclusions in the halite crystals. At 641.9 ft there 

is a -|-in. parting of clay containing a few small pirssonite crystals and at 649.4 ft there is a 1-in. bed 

of fine-grained trona; remainder of unit is relatively 

pure. Massive; crystals randomly oriented.

653.4 3. 4 Trona*, with local concentrations of halite forming up 

to 50 percent of material. Trona crystal sizes at 

base up to 10 mm, but through most of section do not

exceed 2 mm and average about \ mm; halite crystal

sizes up to 20 mm, average about 10 mm. Clay impurities occur in top 8 in. and bottom 2 in. Trona 

is massive, locally vuggy.

656.7 3.3 GlctVj WlUl aftPUt 50 percent crystals, mostly pirssonite* 

and some northupite*. Pirssonite Cry2t9l SlZGS UP

tO 25 mm; average atlOUt 6 ia.ni; northupite crystals

average about 3 mm in size. Colors range frODlpale 

greenish yeUow (10Y8/2) to grayish olive (10Y4/2); 

local concentrations of greenish gray (5GY6/1). Most 

of this unit shows a varvelike banding which appears 

"wrap around" crystals.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

SEARLES DRILL HOLE L-W, L-W-D-Continued

Unit

(feet} thickness Description 

* ' (feet)_____ _________ _____

660.0 3.3 No core.

668.1 8.1 Clay, with about 40 percent pirssonite. Crystal sizes 

up to about 10 mm, average about 4 mm. Yellowish 

gray (5Y7/2) to pale olive (10Y7/2). The following 

exceptions within this unit are notable: At 662.8 ft 

there is a i-in. bed of exceedingly fine grained material* which has an average refractive index of 

1.525 and low to moderate birefringence; it may be 

a devitrified glass or tuff. From 664.6 to 665.1 ft 

crystals of pirssonite and northupite, about one-half 

mm or less in size, are found; about 10 percent clay. 

From 666.8 to 667.6 ft the material is similar to that 

between 664.6 and 665.1 ft; several thin layers consist 

entirely of sand-sized northupite crystals. At 667.6ft 

a 2-in. bed of halite has crystals up to 12 mm, and 

average about 5 mm in size. Generally massive; 

crystals randomly oriented.

670.0 1.9 No core.

676.6 6.6 Sand, crystal; consists of fine to medium sand-sized 

fragments, mainly pirssonite*, a little northupite*, 

and about 10 percent clay. Pale olive (10Y6/2). 

Bottom 6 in. is predominantly clay containing pirssonite crystals up to 5mm in size. Very poorly consolidated; probably cuttings, not core.

677.3 .7 Clay, with about 30 percent pirssonite and a little northupite*. Crystal sizes up to 3 mm, average about 

1 mm. Greenish gray (5GY4-5/1). Massive. At 

676.6 ft there is a 1-in. truncated spherical mass of 

trona*-consisting of a "shell" of silt-sizedtronasurrounding a "core" of coarse sand-sized trona crystals. The clay surrounding this mass shows a concordant banding, and the truncated end is bounded by 

the normal lithology of the core. The cause and significance of this structure are not known.

680.0 2.7 No core.

680.3 .3 Sulfohalite*; a little pirssonite*, tychite*, trona*, and 

clay. Crystal sizes up to 3 mm, average fine-sand 

size. Massive.

680.9 .6 Clay, with about 75 percent northupite. Crystal sizes 

up to 3 mm, average very fine sand size. Pale olive 

(10Y7/2). Massive.

681.1 .2 Clay, with about 40 percent pirssonite. Crystals average medium-sand size. Yellowish gray (8Y7/2). Massive.

681.7 .6 Trona. Crystal sizes up to about 3 mm, average 1 mm. 

Upper half contains several zones of impure trona 

2 to 3 mn. thick. Massive; crystals randomly oriented. 

Locally vuggy.

684.0 2.3 Trona and halite; predominantly trona* in upper part 

but grades into halite* towards the bottom. Crystal 

sizes in upper part up to 6 mm, average about 3 mm; 

crystal sizes in lower part up to 15 mm, average 

about 8 mm. Massive.
44

p.4 ee

GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D-Continued

Depth Unit

thickness Description

(feet)

684.7 0.7 Clay, with about 40 percent pirssonite*. Crystals up 

to 8 mm long, .average about 5 mm, although near 

the bottom there are two i-in. zones in which most 

of the crystals measure less than 1 mm. Grayish 

olive (10Y5/2) to yeUowish gray (5Y7/3), stains of 

moderate yellowish brown (10YR5/4). Massive; 

crystals randomly oriented.

687.1 2.4 Halite and a little trona. Crystal sizes up to 12 mm, 

average about 4 mm. At 685.7 ft there is a 2-in. 

bed of clay containing about 40 percent pirssonite 

crystals which average about 4 mm in size; clay is 

yellowish gray (5Y7/2). Massive.

687. 5 .4 Clay, similar to clay at depth of 684.7 ft; crystal sizes

up to 8 mm, average about 5 mm. 

690.0 2.5 No core.

692.3 2.3 Sand, crystal, coarse; about 80 percent pirssonite*, 

about 15 percent trona*, and a little quartz* and 

clay*. Greenish gray (5GY5/1). Poorly consolidated. May be cuttings, not core.

693.0 .7 Halite, crystal sand, and clay in an undifferentiated 

mixture. Halite crystals up to 10 mm in size, aver-- 

age about 4 mm. Crystal sand is similar to that in 

unit above. Core badly shattered during drilling.

694.4 1.4 Gravel, crystal; mostly halite, probably some trona and 

pirssonite. Fragment sizes up to 15 mm, average 

about 5 mm. Bottom 2 in. consist of solid crystalline 

trona and a little halite grading down into alternating 

clay and fine-grained halite and trona. Except for 

this part, unit is poorly consolidated.

700.0 5.6 No core.

701.7 1.7 Claystone. Microscopic examination shows a mixture 

of clay* and an isotropic substance with the following 

properties*: maximum refractive index slightly less 

than 1.53, cryptocrystalline, groups of radial aggregates show spherulitic extinction; this may be a devitrified glass of volcanic origin. At 700. 5 ft there 

is a 1-in. unit containing thin beds of alternating clay 

and halite which cleave as if a single crystal. In the 

bottom 4 in. there are several large clear randomly 

oriented crystals of halite. Overall color is medium 

light gray (N6) with small mottlings of a pale yellowish orange (10YR8/6). Massive except as noted.

Grades into unit below

710.0 8.3 Halite* and clay. Crystal sizes up to 28 mm, average 

about 6 mm. The halite contains up to 5 percent clay, 

and local concentrations up to about 10 percent occur 

at the following depths; 3 in. at 703.8 ft; 17 in. at 

704.5 ft; 5 in. at 707.5 ft; 6 in. at 708.6 ft; and 2 in. 

at 709.8 ft. From 702. 5 ft to 703.2 ft is a bed of 

clay that contains about 10 percenthalite as silt-sized 

crystals and fragments and as larger veinlets or 

stringers. Yellowish gray (5Y7/3). Massive.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

SEARLES DRILL HOLE L-W, L-W-D-Continued

(feet) thickness Description

________(feet)_______________________________________ __ 717.5 775 Clay, with pirssonite* content ranging from about 20~to 

60 percent. Crystal sizes up to 25 mm, average about 

8mm. The larger crystals are concentrated between 

713.3 and 714.4 ft, and at 714.6 ft is a single crystal 

of halite 25 mm across containing several |~in. blebs 

of brilliant blue color. The clay is mottled and includes pale greenish yellow (10Y8/2), pale olive 

(10Y6/2), yellowish gray (5Y7/2), grayish yellow 

(5Y6/4), and moderate yellowish brown (10YR5/4). 

Orientation of crystals is generally random but locally radial. Massive.

719.0 1.5 Siltstone; consists of quartz*, plagioclase*, orthoclase*, clay*, and about 30 percent pirssonite*. Contains randomly oriented 1 mm veinlets of pirssonite 

up to about 20 mm long. Pale olive (10Y7/2) to greenish gray (5GY6/1), with small mottlings of moderate 

yellowish brown (10YR5/4). Massive. 

720.0 1.0 No core.

720.7 .7 Sandstone; about 80 percent silicates (quartz*, feldspars*, and hornblende)* and 20 percent pirssonite* 

cement. Fragments average about fine-sand size except for a 1-in. zone of coarse sand. Many cavities 

about i mm wide. Greenish gray (5GY6/1). Massive.

722.8 2.1 Clay; about 10 percent crystals, apparently all pirssonite; crystal sizes up to 8 mm, average about 4 mm. 

Mottled; includes the following colors: yellowish 

gray (5Y7/2), grayish yellow (5Y7/4), greenish gray 

(5GY6/1), andalittle staining of light brown (5YR5/6). 

One thin streak of sand was noted, and at 721.4 ft 

there is a 2-in. bed similar to the sandstone above. 

Massive.

730.0 7.2 Halite*; top part up to 15 percent pirssonite*. Halite 

crystal sizes up to 40 mm, average about 6 mm. At 

723.3 ft a few very small negative crystals were 

noted within the halite. Average amount of clay is 

less than 5 percent with the following exceptions: at 

723.0 ft a i-in. bed 50 percent clay; at 724.6 ft a 

parting of clay that contains pirssonite; at 726.3 ft a 

bed about 70 percent clay; at 727.8 ft a 3-in. bed 

about 10 percent clay; at 728.4 ft a i-in. bed about 

10 percent clay. Massive.

733.5 3.5 Halite. Crystal sizes up to 36 mm, average about 5 mm. 

Unit is free of other material with the following exceptions: at 731.8 ft there is alO-in. bed of granular 

halite up to about 10 percent clay; at 730.8 ft the halite 

contains several small crystals of northupite*. Massive.

734.0 .5 Sand, crystal, grading down to claystone; sand part 

about 80 percent pirssonite as crystals, fragments, 

and cement, the remainder is clay. Crystal sizes up 

to 4 mm, average 1 mm. Claystone consists of clay 

cemented by pirssonite and is crosscut by veins of 

pirssonite* up to 1 mm thick. Lower two-thirds of 

this unit shows bedding, fine in the upper part grading to laminar in the lower part. Unit is poorly sorted, 

very well consolidated.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D Continued

Depth (***+} thickness Description

(feet) (feet) __________________________________________

740. 0 6. 0 No core.

742. 5 2. 5 Clay, with up to 15 percent pirssonite as crystals and 

veins. Crystal sizes up to 10 mm, average about 

2 mm. Pale greenish yellow (10Y7/2) to pale olive 

( 10Y 5/2) . Unit shows very indistinct bedding locally.

743. 6 1. 1 Siltstone; mainly clay* and feldspars*. Upper part is 

apparently barren of evaporite minerals; lower part 

contains veinlets and grains of pirssonite measuring 

up to about 3 mm. Light greenish gray (5GY7/1) to 

yellowish gray (5Y7/2). Massive.

744.0 .4 Gravel, crystal; consists of pirssonite, halite, and clay. 

Crystal fragment sizes up to about 5 mm, average 

about 2 mm. Poorly consolidated; probably cuttings, 

not core.

746. 7 2. 7 Clay containing about 30 percent pirssonite. Crystal 

sizes up to about 10 mm, average about 5 mm. Top 

2 in. is highly indurated, very fine grained, and contains up to about 85 percent pirssonite*; this, with 

the clay, locally gives the appearance of a chert. 

Colors include pale greenish yellow (10Y7/2), grayish 

yellow (5Y7/4), and medium gray (N5). Massive.

750.0 3.3 No core.

750. 6 . 6 Gravel, crystal; consists of pirssonite, trona, probably other minerals, and a little clay. Poorly consolidated. Probably cuttings, not core.

752.9 2.3 Clay containing an average of about 15 percent pirssonite. Crystal sizes up to 7 mm, average less than 

1mm. Pale greenish yellow (10Y7/2). Within this 

. unit, from 750. 6 to 751. 3 ft, is a zone of "pirssonite 

breccia, " a rock containing about 70 percent angular 

to rounded fragments of pirssonite crystals up to 

5 mm in size, cemented by pirssonite*; the cement 

is milky adjacent to the fragments and clearer toward the interstitial centers. In this "breccia" are 

a few cavities up to 5 mm wide which contain crystals of pirssonite. At 751. 4 ft there is a 2 mm bed 

of fine sand-sized northupite* crystals. Massive.

754. 6 1.7 Gravel, crystal; consists of fragments of pirssonite, 

halite, and probably other minerals and up to 20 percent clay. Crystal sizes up to 15 mm, average about

4 mm. At 754. 1 ft there is a 1-in. bed of massive 

pirssonite containing about 10 percent clay. Pale 

greenish yellow (10Y7/2). Poorly consolidated except as noted above.

756. 0 1.4 Clay containing about 40 percent pirssonite in crystal 

sizes up to very coarse sand size. Yellowish gray

(5Y7/2) to pale greenish yellow (10T7/2). Massive.

758. 2 2. 2 Halite* and a little clay. Crystal sizes up to 23 mm, 

average about 8 mm. Average clay content is about

5 percent; the following are exceptions: at 756. 3 ft 

a ir-in. bed containing about 50 percent clay; at 

756. 7 ft, a 1-in. bed of clay; at 757. 6 ft a 1-in. bed 

of clay. Massive. 

760. 0 1.8 No^ore.
47 

CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

SEARLES DRILL HOLE L-W, L-W-D-Continued

Unit

thickness Description 

( feet)__________________________________________

761. 2 1. 2 Halite and clay; percentage of clay increases downward 

from less than 5 to about 90 percent. Crystal sizes 

up to 15 mm, average about 8 mm. Clay in lower 

part contains about 5 percent pirssonite in crystal 

sizes up to about 1 mm. Color ranges from yellowish gray (5Y7/2) to pale greenish yellow (10Y7/2), 

averages about grayish yellow (5Y7/4). Massive.

764.9 3.7 Clay, with pirssonite. Pirssonite in top 8 in. constitutes about 30 percent of total; crystal sizes are generally less than 1 mm. Pirssonite in remainder of 

unit constitutes about 20 percent of total; crystal 

sizes up to 15 mm, average about 8mm.. Colors 

mottled, include grayish yellow (5Y7/4), light brown 

(5YR5/6), light greenish gray (5GY8/1), and grayish 

yellowish orange (10YR7/5). Massive.

766. 3 1.4 Halite, with clay. Percentage of clay ranges from 5 to 

60 percent, averages about 30 percent. Halite crystal sizes up to 18 mm, average about 5 mm. The 

lower percentages of clay are in the middle of this 

unit'. Colors mottled, average yellowish gray 

(5Y7/4). Massive; crystals randomly oriented.

768.1 1.8 Clay, with about 10 percent pirssonite* and 5 percent 

halite. Crystal sizes up to 15 mm, average about 

7 mm. Colors similar to those at depth of 764. 9 ft. 

Massive.

769.4 ' 1.3 Halite*, with about 20 percent clay. Crystal sizes up 

to 38 mm, average about 5 mm. Clay is light greenish gray (5GY7/1). Massive.

770.0 .6 Clay, with about 50 percent pirssonite and 20 percent 

halite; a little northupite. Halite crystal sizes up to 

4 mm, average about 2 mm; pirssonite crystal sizes 

are generally less than § mm; northupite crystals 

measure about 4 mm. Clay is pale olive (10Y5/2). 

Fine to laminar bedding, generally defined by alternation of the sets of minerals. Halite is concentrated 

in lower part.

775. 4 5. 4 Sand, crystal, grading down to crystal gravel. Consists of pirssonite, halite, and probably other minerals. In the top foot there are numerous chips of 

claystone similar to that at 734.0 ft and of "pirssonite 

breccia" similar to that at 750.6ft. At 770. 9ft there 

is a 3-in. bed of clay containing 5 to 40 percent pirssonite. Poorly consolidated; may be cuttings, not 

core.

776.0 .6 Sandstone, medium-grained; grades down to clay. Sand 

consists of pirssonite* and northupite* in equal proportions and constitutes about 95 percent of the total. 

Clay part contains much fragmentary material and 

white partings of fine-grained material, both of which 

are probably pirssonite. Pale yellow (10Y6/2) to 

grayish olive (10Y4/2). Thin to laminar bedding.

776.8 .8 Sand, crystal, very coarse. About 90 percent fragments of pirssonite, trona, and probably other minerals, in a clay matrix. Pale olive (10Y6/2). Poorly 

consolidated; probably cuttings, not core.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D Continued

Unit

thickness Description 

(feet)

778. 7 1. 9 Clay, with about 10 percent pirssonite. Crystal sizes 

up to 12 mm, average about 4 mm. Yellowish gray 

(5Y7/2) to light greenish gray (5GY7/1). Faint bedding defined by color changes; also partings of dusky 

yellow green (5GY4/2). At base there is a 1-in. bed 

of coarsely crystalline halite.

781.0 2.3 No core.

781. 7 . 7 Sand, crystal, medium, and clay. Sand consists of 

about 95 percent pirssonite, and probably other minerals, in a clay matrix. Bottom 2 in. is clay with 

about 10 percent pirssonite; crystal sizes up to 10 mm, 

average about 1 mm. Sand is pale olive (10Y6/2); 

clay is yellowish gray (5Y7/3). Massive. Grades 

into unit below.

782.3 .6 Halite*, with '5 to 10 percent clay. Crystal sizes up to 

33 mm, average about 8 mm. Clay is dusky yellow 

(5Y6/4). Massive.

783. 5 1.2 Clay, with about 20 percent pirssonite. Crystal sizes 

up to 7 mm, average about 3 mm. Colors mottled, 

include yellowish gray (5Y7/3), pale greenish yellow 

(10Y7/2), and streaks of light brown (5YR5/6). Indistinct thin bedding defined by color changes.

783. 8 . 3 Halite, with up to 50 percent clay. Maximum crystal 

size 30 mm, average about 1.0 mm. Halite generally 

massive, locally radial. Dark greenish gray 

(5GY5/1).

784.0 .2 Silt; consists of sulfohalite* crystals and fragments, 

and about 10 percent clay. Grayish yellow (5Y7/4). 

Massive.

784. 5 . 5 Conglomerate, crystal; consists of rounded fragments 

cemented by clay, pirssonite, and a little northupite*. 

Fragments constitute about 40 percent of the rock, 

and range in size from about 3 to 7 mm. They consist of a dark-gray (N3) very fine grained material 

similar to the claystone at 734.0 ft. A few vugs 

noted which contain pirssonite and northupite crystals. Clay is light olive gray (5Y5/2). Massive.

786.5 2.0 Pirssonite*, with about 30 percent clay. Pirssonite 

blades, up to 30 mm long, form large radial aggregates; the clay fills the interstices of these radial 

aggregates, Yellowish gray (5Y6/2) to pale olive 

(10Y6/2). Massive, except for. a little local fine to 

laminar bedding.

788.8 2.3 Gravel, crystal, consists of about 60 percent pirssonite* 

crystals in a clay matrix; percentage of crystals 

ranges locally from about 40 to about 90 percent. 

Crystal sizes up to 15 mm, average about 7 mm. 

Colors include pale olive (10Y5/2), pale greenish 

yellow (10Y7/2) } and grayish yellow (5Y7/4). Massive. Crystals randomly oriented.

791. 0 2. 2 No core.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

SEARLES DRILL HOLE L-W, L-W-D-Continued

Unit

Depth thickness Description 

(feet) (feet)

791.7 0.7 Sand, crystal; consists of about 80 percent fragments 

of pirssonite* in a matrix of clay and a fine-grained 

white mineral which is probably pirssonite. Fragment sizes up to 3 mm, average about 1 mm. Pale 

olive (10Y6-7/2) with streaks of white (N9). Local. 

faint thin bedding. Material is well consolidated and 

looks like a sand-sized breccia.

800. 0 8. 3 No core.

801. 3 1.3 Sand, crystal, coarse, similar to crystal sand at depth 

of 776. 8 ft. At base of unit there are several large 

fragments of halite and clay similar to those at depth 

of 782. 3 ft, but clay contains a few crystals of gaylussite*. Probably cuttings, not core.

804.9 3.6 Clay. Colors include pale greenish yellow Q.OY9/2), light 

yellowish gray (5Y9/1) , and light greenish gray (5GY9/3) ; 

small zones are slightly darker. Generally massive; 

local laminar bedding defined by color changes . Local 

concentrations of pirssonite in crystals up to 5mm in 

size as follows: al-in. layer at 803. 5 ft, a 2-in. layer 

at 804. 2 ft, and a 1-in, layer at 804.8 ft.

805. 4 . 5 Clay, with up to 50 percent sand-sized fragments of 

pirssonite. Colors include dark greenish gray 

(5GY4/1), light greenish gray (5GY7/1), dusky yellow 

(5Y6/4), and grayish orange (10YR6/4). Thin to 

laminar bedding defined by color changes.

810. 0 4. 6 No core.

816. 7 ,6. 7 Sand, crystal, medium, grades down to coarse. Contains pirssonite and probably other minerals. Pale 

olive (10Y6/2). Poorly consolidated; probably cuttings, not core.

817. 3 . 6 Clay, with about 25 percent pirssonite. Crystal sizes 

up to 10 mm, average about 2 mm. Pale olive 

(10Y5/2) to yellowish gray (5Y6/3). Thin indistinct 

bedding caused by orientation of crystal blades and 

color changes.

818. 1 . 8 Sand, crystal, similar to crystal sand at depth of 

776. 8 ft.

820. 0 1.9 Clay*, with about 30 percent pirssonite, locally about 

60 percent. Pirssonite crystals- and fragments range 

from very fine grained to about 10 mm in size and 

average about 2 mm; fragments appear brecciated 

and are distributed heterogeneously. Colors include 

pale olive (10Y6/2), pale greenish yellow (10Y8/2), 

light grayish yellow (5Y9/4), yellowish gray (5Y6/2), 

and light gray (N7). Generally massive; local fine 

bedding. Core badly shattered during logging.

821.6 1.6 Clay containing up to about 60 percent pirssonite*. 

Crystal sizes up to about 10 mm, average about 

2 mm. Pale greenish yellow (10Y8/2) to yellowish 

gray (5Y7/2). Massive. Grades into unit below.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

SEARLES DRILL HOLE L-W, L-W-D-Continued

(fZ, ±\ thickness Description

(feet) (feet) __________________________________________

828. 6 7. 0 Clay; local concentrations of pirssonite. Predominant 

colors are several hues near white; also pale olive 

(10Y6/2) and light olive gray (5Y5/3). Pirssonite 

occurs at the following depths: at 826. 0 ft, a 7-in. 

zone containing about 40 percent pirssonite in crystals up to 2 mm; at 826. 8 ft, a similar 1-in. zone; 

at 827. 3 ft, a 2-in. zone containing 50 percent pirssonite in crystals up to 2 mm; at 827.6 ft, a 1-ft 

zone containing locally up to 60 percent pirssonite in 

crystals up to 3 mm in size. Clay parts of the unit 

show a laminar banding in contorted "marble-cake" 

structures.

830. 0 1.4 Silt, crystal, with up to 40 percent clay. Crystals are 

about 70 percent pirssonite* and 30 percent northupite*; the northupite is generally concentrated in 

small irregular bodies. Crystals up to medium sand 

size, average silt size. Pale olive (10Y6/2) to 

yellowish gray (5Y7/2). Massive. At base there is 

a i-in. bed of fine-grained trona*.

830. 6 . 6 Clay, with about 30 percent pirssonite. Crystal sizes 

up to 4 mm, average 2 mm. Pale olive (10Y6/2). 

Core badly shattered.

830. 7 . 1 Claystone, similar to claystone at a depth of 734. 0 ft.

833. 1 2. 4 Trona* and a little halite. Crystal sizes up to 3 mm, 

average 2 mm. At 831. 0 ft there is a 3-in. bed of 

clay about 50 percent pirssonite in crystal sizes up 

to 8 mm, average 2 mm. Dusky yellow green 

(5GY5/2). Trona crystals randomly oriented. Unit 

shows' very faint bedding caused by horizontal zones 

containing trace amounts of clay.

834. 2 1. 1 Clay, with up to 40 percent pirssonite. Crystal sizes 

up to 3 mm. Pale olive (10Y5/2) to light olive gray 

(5Y5/2), locally pale greenish yeUow (10Y8/2). At 

833. 4 ft there is a 2-in. bed of clay containing no 

"pirssonite and showing indistinct fine to laminar bedding; pale greenish yellow (10Y9/2). Remainder of 

unit also locally shows indistinct thin bedding,

840. 0 5. 8 No core.

840. 1 . 1 Claystone, similar to claystone at a depth of 734. 0 ft. 

845.0 4.9 No core.

846. 0 1.0 Clay, with up to 10 percent pirssonite, a few crystals 

of northupite*. Pirssonite crystals are coarse sand

size; northupite crystal sizes are up to 5 mm. Pale

olive (10Y6/2) to several hues near white. Generally 

massive, locally banded.

850. 2 4. 2 Sand, crystal, medium; contains pirssonite, trona,

and probably other minerals. Pale olive (10Y6/2).

At 849. 4 ft there is a 1-in. bed of clay similar to unit 

above. Poorly consolidated.

851. 0 . 8 Clay, silty in lower part. Grayish yellow (5Y8/4) and 

several hues near white. Massive.

852.1 1.1 Sand, crystal, coarse to very coarse; contains pirssonite, trona, and probably other minerals. Pale 

olive (10Y6/2). Poorly consolidated.

855. 0 2. 9 No core.
C1

CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

_______SEARLES DRILL HOLE L-W, L-W-D-Continued 

____ __

^ poo^-^ thickness Description

(feet) (feet)___________________________________________

859.4 4.4 Sand, crystal, grading downward from fine to medium. 

Similar to crystal sand at depth of 850. 2 ft.

860.0 .6 Clay; about 5 percentpirssonite*, as crystals and veinlets. Veinlets measure up to 10 mm long, crystals 

up to 2 mm. Pale greenish yellow (10Y7-8/2) to 

yellowish gray (5Y7/2). Massive; veinlets and crystals randomly oriented.

862. 5 2. 5 Pirssonite, with about 20 percent clay. Crystals are 

tightly intergrown and irregularly shaped; sizes up 

to 10 mm, average about 3 mm. Yellowish gray 

(5Y7/2) to greenish gray (5GY5/1) to medium gray 

(N5). At 861.3ft there is a 2-in. bed of crystal sand, 

yellowish gray (5Y7/2), containing about 50 percent 

pirssonite crystals; at 862. 3 ft there is a 4-in. bed 

of clay, pale greenish yellow (10Y7/2), containing 

about 10 percent pirssonite crystals. Remainder of 

unit is massive.

865.0 2. 5 Clay, with about 10 percent pirssonite, locally up to 

60 percent. Crystal sizes up to 10 mm, average 

about 2 mm. Light olive gray (5Y6/1) to yellowish 

gray (5Y7/2). Massive.

869. 3 4. 3 Siltstone; consists mostly of pirssonite* silt cemented 

byclayand pirssonite;local beds of intergrown pirssonite .crystals similar to those at depth of 862. 5 ft. 

Colors range from light greenish gray (5GY7/1) to 

dark greenish gray (5GY3/1) to pale olive (10Y6/2). 

Entire unit very well indurated^ Local thin bedding.

873. 5 4. 2 Clay, similar to clay at depth of 865.0 ft, except that 

pirssonite does not exceed 10 percent.

875.0 1.5 No core.

PANAMINT DRILL HOLE 1, la

[Panamint"~l, surface to 450 feet; Panamint la, 450 to 500 feet; sixty percent of core recovered]

Unit

Depth thickness Description 

(feet) (feet)____________________*______________________

6.0 6.0 No core.

40.5 34.5 Silt, dusky-yellow (5Y6/4), very well sorted, calcareous. Apparent bedding defined by color changes.

50.8 10.3 Silt, clayey, to clay, grayish yellow (5Y8/4), well 

sorted, massive, calcareous.

55.0 4.2 Clay and some silt, yellowish-gray (5Y7/2) to pale-olive 

(10Y6/2).

59.0 4.0 Silt, clayey, yellowish-gray (5Y7/2) to dusky-yellow 

(5Y6/4); fine laminar bedding; calcareous; fine beds 

of gypsum interspersed.

64.0 5.0 Silt, clay, and a little gypsum* interbedded; color 

ranges from medium light gray (N6) to greenish 

gray (5GY6/1) to light greenish gray (5GY8/1). 

Gypsum is in thin beds.

65.0 1.0 Clay, silty; contains nodules of limestone; light greenish gray (5G8/1); massive.
52 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

PANAMINT DRILL HOLE 1, la-Continued

DepthUnit

f£~4.\ thickness Description

(feet) (feet)__________________________________________

71.0 6.0 Clay, silty; pockets of gypsum crystals; light greenish

gray (5G8/1); thinly bedded; calcareous. 

98.5 27.5 Clay and a little silt, light greenish-gray (5GY8/1),

thinly laminated, calcareous. Thin silt and clay

beds are very carbonaceous, core had strong odor

of H 2S when fresh. 

99.5 1.0 Clay and a little silt, greenish-gray (5GY8/1). Similar

to unit above. Ostracodes, two species, observed

in 98 to 101 ft interval. 

105.0 5.5 Clay and a little silt, light greenish-gray (5GY8/1),

thinly laminated, calcareous; very carbonaceous

beds.

153.0 48.0 Clay and a very small amount of silt, light greenishgray (5GY8/1) to (5G8/1). Carbonaceous bedding

lines, laminar, in top 20 ft; bedding is less pronounced

and thicker (maximum about 1 in.) in lower part.

Ostracodes observed from about 112 ft to bottom of

unit; diatoms in some zones; chara at 150 ft. 

155.0 2.0 Silt and a little fine sand; greenish gray (5GY6/1) to

light greenish gray (5GY8/1) in lower part; massive;

very calcareous. Ostracodes. 

165.0 10.0 Clayey silt and silty clay, light greenish-gray (5GY8/1);

no distinct bedding planes except near top where the

bedding is thin; calcareous. 

185.0 20.0 Clay and silty clay, greenish-gray (5GY6/1), thinly

bedded, calcareous; slightly carbonaceous. Diatoms

and ostracodes visible. 

210.0 25.0 Clay and silty clay, light'greenish-gray (5GY8/1),

massive, calcareous; salty. Contains ostracodes

and diatoms.

210.5 .5 Gypsum* crystal aggregate, yellowish-gray (5Y8/1). 

228.8 18. 3 gut and clay; color ranges from yellowish gray (5Y8/1)

to light greenish gray(5G8/l); massive; calcareous.

Gypsum crystals diminish downward from 2 to

0 percent of the material. One inch of very fine sand

at 227.3ft. 

230.0 1.2 Sand, very fine, and Silt; light Olive gray (5Y6/1);

massive; calcareous. 

246.6 16.6 Silt and clay, yeUowish-gray (5Y7/2), massive,

calcareous. 

255.0 8.4 Clay and Silty Clay, light greenish-gray (5GY8/1), fine

laminations, calcareous; carbonaceous. 

259.5 4.5 Silt, yellowish-gray (5Y7/2), massive, calcareous.

Visible ostracodes. 

269 0 9.5 Silt, with much clay, very light gray (N8), thinly

bedded. At 259.9 ft there were laminae of bassanite*, calcite*, and gypsum*. 

270.0 1.0 Sand, very fine, to silt, yellowish gray (5Y7/2),

laminar bedding. 

280,0 10.0 Silt to clay, yellowish-gray (5Y7/2); massive except

for bottom 3 In.. WhiCh are laminar; very calcareous.

Ostracodes abundant.

287.6 7.6 Silt, moderate grayish-yellow (5Y7/4), massive, calcareous.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

PANAMINT DRILL HOLE 1, la-Continued

D th Unit

/ f , \ thickness Description 

Ifeet J

310.0 22.4 Silt; greenish gray (5GY6'/1) in upper part grading to

light olive gray (5Y6/1) in lower part; calcareous;

gypsiferous, locally as much as 15 percent but

overall average is 2 percent. 

315.0 5.0 Silt, greenish-gray (5GY6/3), massive, slightly mottled;

calcareous; carbonaceous(7).

339.8 24.8 Silt, dusky-yellow (5Y6/4), massive, calcareous. 

350.0 10. 2 Sand, medium, to clay; average is fine sand; very light

gray (N8) to light greenish gray (5GY8/1); massive;

bottom 2 in. finer grained; calcareous in silt and

clay zones. 

358.0 8.0 Silt, moderate grayish- yellow (5Y7/4), massive, calcareous. 

360.0 2.0 Silt to fine sand, light-gray (N7). Bedding laminar to

1 in. ; irregular pods (10 percent of total volume) of

pure fine-grained calcite. 

370.0 10.0 Silt to fine sand, greenish-gray (5GY6/1), massive.

Up to 5 percent calcite in upper part diminishing

downward. Bottom foot is conglomeratic; pebbles,

up to 1 in. in size of metamorphic rocks. 

378.4 8.4 Silt, yellowish-gray (5Y7/2), massive, calcareous.

386.0 7.6 Silt to fine sand; light olive gray (5Y6/1) grading to

white (N9) in highly calcareous zones, massive. At

380 ft there is a pebble of subangular metamorphic

rock 1 in. in diameter; may be from zone above. 

408.0 22.0 Silt, a little clay, light olive-gray (5Y6/1), massive,

calcareous . 

417.0 9.0 Clay, silty, to silt; pale olive (10Y6/2); massive;

calcareous. 

418.7 1.7 Clay, silty; mottled colors averaging greenish gray

(5GY6/1); calcareous. 

420.0 1.3 Clay, silty; pods of limestone; light greenish gray

(5GY8/1); fine laminar bedding. 

430.0 10.0 Silt to fine sand, light greenish-gray (5GY8/1), massive, calcareous. 

440.0 10.0 Carbonate, silty, white (N9) to light greenish-gray

(5GY8/1), massive. 

442.0 2.0 Silt to very fine sand; light greenish gray (5GY8/1) to

greenish gray (5GY6/1) in mottled patterns; massive;

pods of carbonate. 

450.0 8.0 Silt, pale-olive (10Y6/2), calcareous, massive. (End

of Panamint drill hole 1 . ) 

470.0 20.0 Silt and a little clay, grayish-yellow (5Y8/4), generally

massive, calcareous. 

471.0 1.0 Silt and a little clay, yellowish-gray (5Y7/2),with pods

of white (N9) limestone; massive. 

494. 7 23. 7 Silt, and a little clay, grayish-yellow (5Y8/4), generally

massive, calcareous. 

495.0 .3 Silt and a little clay, yellowish gray (5Y7/2), and few

pods of white (N9) limestone. 

500 . 0 5.0 Silt and a little clay, grayish-yellow ( 5Y8/4) , massive ,

calcareous.
54 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

PANAMESTT DRILL HOLE 2

[Fifty-eight percent of core recovered]

Depth Unit

/>cL-i-'\ thickness Description

(feet) (feet)__________________________________________

10.0 10.0 No core; probably all sand, coarse to fine.

17.0 7.0 No core; probably sand to silt.

19.8 2.8 Sand to silt, greenish-yellow (10Y7/2), massive. Sand 

grains of quartz (about 90 percent of sand), feldspar, 

biotite (euhedral, bleached to a golden color), iron 

oxide-coated quartz, possibly some pyroxene and 

hornblende. Calcareous.

21.5 1.7 Clay, fragments of rounded feldspar crystals, and 

euhedral biotite; yellowish gray (5Y8/1); massive. 

Streaks (1 mm average width) of hematite* generally 

parellel to bedding but some are perpendicular. Spots 

of black flakes (may be. iron or manganese oxides). 

Irregular patches (up to 1 in. long) of brown stains, 

darker than hematite stains.

21.9 .4 Sand, coarse to fine, pale greenish-yellow (10Y8/2). 

Subangular quartz and feldspar, about 5 percent 

mica; streaks of reddish iron oxide. Calcareous.

22.4 .5 Clay, yellowish-gray (5Y8/1). Scattered flakes of biotite, some zones of iron oxide. A few stringers of 

coarse sand. Calcareous. Massive.

22.7 .3 Sand, similar to sand at depth of 21.9 ft.

23.2 .5 Clay containing about 5 percent quartz- and feldsparsand fragments, yellowish-gray (5Y8/1), massive, 

calcareous.

23.7 .5 Sand, medium, yellowish-gray (5Y7/2), well-sorted, 

subangular; about 10 percent biotite flakes; calcareous.

26.8 3. 1 Clay; contains about 1 percent subangular fragments of 

fine to coarse sand; pale greenish yellow (10Y8/2); 

much biotite, generally euhedral; calcareous.

30.0 3.2 No core.

38.0 8.0 Core destroyed while being removed from core barrel; 

sludge fragments indicate most of core was clay, 

yellowish gray (5Y8/1), with fragments of coarse 

sand forming about 5 percent of total. Some layers

of coarse to very coarse sand.

40.7 2.7 Sand, fine to very fine, yellowish-gray (5Y7/2), massive, well-sorted. Many biotite flaKes up to i mm

diameter. Very calcareous.

41.2 .5 Pebble gravel, light greenish-gray (5GY8/1). Matrix

of clay. Fragments are of large crystals(?) of 

feldSDar aild quartz, and fine-grained volcanic(?) 

rocks. Ratio of pebbles to matrix is 1 to 3. Ced«a.raaua.

44.8 3.6 Silt, some beds of fine to very fine sand; yellowish Cfr'ay1

(5Y8/1). Sand beds up to 2 in. thick. 

50.0 5.2 No core; probably fine sand, pebbly sand, and some clay.

51.6 1.6 Granule and clay mixture, yellowish-gray (5Y8/1). 

Granules up to 3 mm in diameter, subrounded to 

subangular, composed of basalt and individual minerals. May be cuttings, not core.

51.8 .2 Sand, very fine, light greenish-gray (5GY8/1). Contains larger fragments of quartzite and limonite(?). 

Massive. Calcareous.

60.0 8.2 No core; cuttings indicate much clay.
KK 

CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

__________PANAMINT DRILL HOLE 2-Continued

Depth Unit

/ p!L+1 thickness Description (feet) ,

1.8 Silt to clay, pale greenish-yellow (10Y8/2). Contains 

some subangular fragments of dolomite( ?) and some 

small flakes of biotite. 

62.0 .2 Clay, pale greenish-yellow (10Y8/2). Contains a 1-in.

rounded fragment of vesicular volcanic rock.

65.0. 3.0 Sand,'fine to medium, some fragments of very coarse 

grained sand; pale olive (10Y6/2). Fragments about 

97 percent feldspar and quartz(?); some biotite, olivine, iron oxide, and rock fragments. Slightly bedded. Calcareous.

70.0 5.0 No core; drilled as if sand.

72.4 2.4 Sand and clay intermixed, pale-olive (10Y6/2). Sand 

similar to sand at 65.0 ft. Contains rounded fragments of dolomite, intrusive rock, and volcanic rock 

up to 10 mm in diameter. Average size about 5 mm. 

Poor core.

80.0 7.6 No core; drilled as if loose sand. 

80.7 .7 Clay, contains fragments up to 1 mm long of feldspar 

and biotite; pale olive (10Y6/2). Bottom 2 in. is 

coarse sand, mainly feldspar.

90.0 9. 3 No core. Drilled as if sand and clay interbedded; interval between 84 and 86 ft mostly clay.

97.6 7.6 Clay, pale greenish-yellow (10Y8/2), massive, homogeneous; core breaks with conchoidal fracture. Contains fragments of biotite up to 0.5 mm in diameter, 

some feldspar(7).

111. 7 14.1 Sand, coarse to very fine, pale-olive (10Y6/2), massive. Fragments angular to subangular, many are 

crystal shaped. Approximate composition: 90 percent feldspar, 6 percent quartz, 3 percent biotite, 

1 percent iron oxide, pyroxene(?), amphibole(?). 

Entire section is very calcareous.

114.5 2.8 Clay, pale greenish-yellow (10Y8/2). Lower half 

shows fine bedding (1 to 5 mm thick); upper half 

shows no bedding. Breaks with a conchoidal fracture. Clay contains 1 mm biotite fragments, some 

pyroxene(?), hornblende(?), and feldspar. Verycalcareous.

114.8 .3 Sand, very coarse, white (N9), well-sorted. Contains 

fragments of biotite and quartz(?), possibly gypsum. 

Noncalcareous.

Ii7.8 3.0 Clay, greenish-yellow (10Y7/2); conchoidal fracture. 

Contains biotite flakes, some iron-oxide stains.

120.0 2.2 No core.

132.4 12.4 Clay, greenish-yellow (10Y7/2); conchoidal fracture. 

Contains flakes of biotite.

135.0 2.6 No core.

158.2 23.2 Clay and silt breccia; pale greenish-yellow (10Y8/2) 

clay fragments in matrix of light-brown (5YR6/4) 

silt. Fragments are angular, range in width up to 

diameter of core (2 in.). Ratio of fragments to matrix is about 2 to 1.

162. 5 4. 3 Silt and clay, yellowish-gray (5Y8/1), massive, calcareous. Very few biotite flakes. Contains moderate orange-pink (5YR8/4) stringers of silt, similar 

to the matrix in the unit above.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

PANAMINT DRILL HOLE 2-Continued

Unit

Depth thickness Description 

( feet) (feet)__________________________________________

167. 5 5.0 Silt and clay, white (N9) to grayish-orange (10YR7/4). 

Contains fragments of feldspar and biotite.

175.0 7.5 Marl, pinkish-gray (5YR8/I). From 50 to 90 percent 

calcite, average about 70. Contains fragments of 

feldspar and biotite.

180.0 5.0 Silt and clay; very pale orange (10YR8/2) grading downward to grayish orange (10YR7/4); massive; calcareous*.

184.0 4.0 Silt and clay, generally very pale orange (10YR8/2); 

stringers of moderate orange-pink (5YR8/4) silt; 

massive; calcareous. At 182. 3 ft a 1-in. fragment 

of vein quartz and smaller pebbles of volcanic rocks 

were found. This unit may be cuttings, not core.

190.0 6.0 Silt and clay, some beds of fine to medium sand; grayish orange (10YR7/4). Well bedded; sand beds up to 

2 in. thick, finer sediments laminar-. Sand fragments 

largely quartz and feldspar, with some biotite 

(bleached), iron oxides, and pyroxene(?). Calcareous.

200.0 10.0 Marl, mottled white (N9) and very pale orange 

(10YR8/2). Mainly CaCO3 with irregular patches of 

silt. Ratio of carbonate to silt is generally about 2 

to 1; some zones about 98 percent carbonate. Transition to unit above is gradational.

208. 2 8.2 Clay and a little silt, pale greenish-yellow (10Y8/2), 

massive. Irregular patches and vertical "dikes" of 

iron oxide stains. Visible minerals: biotite, pyroxene(?), feldspar, iron oxides, possible some iddingsite after olivine. Transition to unit above is gradational over about 2 in.

217.7 9.5 Clay and a little silt, pale grayish-orange (10YR7/2). 

Vertical streaks of light-brown (5YR6/4) finer clay.

219.8 2.1 Gravel, pale grayish-orange (10YR7/2). Matrix of 

fine to medium sand; fragments of subangular to subrounded pebbles (2 to 15 mm; average size about 5 mm) 

of volcanic rocks (andesitic and basaltic; pumiceous) 

and limestones (dusky blue (5 PB3/2) and medium 

gray (N6)).

225.8 6.0 Clay and a little Silt, yellowish-gray (5Y7/2). Vertical streaks of light-brown (5YR6/4) finer clay.

227 4 1.6 Sand, fine to medium, pale grayish-orange (10YR7/2).

23o!o 2^6 Clay, Silt, and fine sand, pale grayish-orange 

(10YR7/2).

240.0 10.0 Gravel, pale grayish-orange (10YR7/2). Matrix is 

fine to medium sand; fragments of volcanic rocks 

and limestones have a maximum diameter of about

5 mm, 

250. o 10. o NO core; sludge cuttings indicate gravel only,

260.0 10.0 No core; gravel(?).

265.0 5.0 No core; solid-bit drill used.

270.0 5.0 Silt and clay, yellowish-gray (5Y7/2), massive. Some

subangular fragments of limestone, 2 to 10 mm in

diameter. 

276.0 6.0 Silt, pale grayish-orange (10YR7/2), massive. A very

few pebbles scattered throughout. Calcareous. Some

darker streaks (carbon?).
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

57

PANAMINT DRILL HOLE 2-Continued

Depth 

(feet)

Unit

thickness 

(feet)

Description

277.0 1.0 Slit, pebbly, pale grayish-orange (10YR7/2). Pebbles 

between 2 and 15 mm wide, averaging about 5 mm; 

composed of volcanic rocks (cinder basaltic rocks 

and limestone). Ratio of pebbles to silt is about 1 to 

10.

279.0 2.0 Sand, very fine, and silt; pale orange (10YR7/2); very 

well sorted. Fine bedding averaging about 1 mm between bedding planes; bottom 6 in. is crossbedded, 

as if windblown.

279.4 .4 Gravel, pale-orange (10YR7/2). Pebbles form about 

80 percent of the unit; rounded to subrounded, between 2 and 20 mm wide, averaging about 8 mm; consist of basaltic rocks, cinder, and quartzite(?).

282.6 3.2 Clay and silt, pale-orange (10YR7/2), well-sorted. At 

281.3 ft and 282.0 ft there are well-cemented 2 in. 

beds of very coarse sand fragments in a matrix of 

solid calcite* and silt; sand consists of angular fragments of feldspar*, quartz*, amphibole*, pyroxene*, 

hematite*, and volcanic rocks*.

290.0 7.4 Sand, fine to very fine, light brownish-gray (5YR6/1), 

massive. Contains a few pebbles of andesitic rocks, 

cinder, and dolomite; round to subroundjup to 20mm 

long.

356.0 66.0 No core; drilled as if gravel.

359. 2 3.2 Clay, very pale orange (10YR8/2), massive.

359.5 .3 Clay, grayish-orange (10YR7/4).

365.0 5.5 Sand, fine, grading into coarse sand at base; grayish 

orange (10YR7/4). Contains pebbles of limestone 

ranging in size from 2 to 10 mm, averaging about 

5 mm; subangular.

375.0 10.0 No core; tricone bit used. Cuttings and drilling characteristics indicate lithology similar to the nearby 

outcrops of Paleozoic limestone.

PANAMINT DRILL HOLE 3

[Forty-seven percent of core recovered]

Depth 

(feet)

Unit

thickness 

(feet)

Description

40.0 40.0 Silt, clayey; pale orange (10YR8/4) average color, but 

varies locally to medium yellowish brown (10YR5/4) 

forming variegated pattern; massive. Angular fragments of mica, hornblende(?). Calcareous.

50.0 10.0 Clay, silty; moderate brown (5YR3/4) to dark yellowishbrown (10YR4/2), massive. Fragments of iron oxide; about 1 percent gypsum at 50.0 ft. Calcareous. 

Bottom 2 ft has many angular fragments (up to 10 mm 

in diameter) of light grayish orange (10YR8/4) clay 

and fine sand.

59.7 9.7 Calcium carbonate, silty; pale greenish yellow 

(10Y8/2) to white (N9) forming variegated color pattern; massive.
GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

PANAMINT DRILL HOLE 3-Continued

/^p . \ thickness Description

(feet) (feet) __________________________________________

60.0 0.3 Silt and halite, calcareous*, grading down to halite; 

pale olive (10Y6/2) to colorless. Crystals in upper 

part are euhedral; in lower part form solid mass.

69.0 9.0 Silt, grayish-orange (10YR7/4), massive. Crystals of 

halite dispersed through silt; also blebs of greenish 

clay up to 2 mm wide. Poor core.

70.0 1.0 Clay, grayish-yellow green (5GY7/2), massive. Euhedral crystals of halite (up to 10 percent of core) 

throughout. Calcareous.

80.0 10.0 Halite, with about 40 percent silt to very fine sand; 

grayish yellow green (5GY7/2). Local laminar bedding. Halite is both euhedral and fragmentary. Thin 

bed of gypsum* and halite* at 78. 0 ft; pure halite between 79. 0 and 79. 5 ft.

90.0 10.0 Halite and silt, grayish- orange (10YR7/4). Core is 

about 60 percent halite; a little gypsum; calcareous. 

Poor core.

159.0 69.0 Halite, generally colorless, but some included silt 

gives yellowish or grayish coloring; massive. Thin 

interbeds of silt at 105.0ft (0. 2 ft thick), 124.0ft 

(0. 3 ft thick), and 133. 0 ft (0. 2 ft thick). A little 

gypsum* and calcite*. Core from 135.0 to 159.0 ft 

is missing; drilling characteristics suggest same 

material as 90. 0 to 135. 0 ft interval.

160.0 1.0 Silt, pale -orange (10YR8/4), massive. Halite crystals 

form about 1 percent of core. Calcareous.

164. 5 4. 5 Clay, silty, to clay. Average color is yellowish gray 

(5Y7/2) with patches that are more orange or green 

thus giving an overall mottled effect. Poor laminar 

bedding in upper part, excellent laminar bedding in 

lower part. Halite crystals form about 5 percent of 

total. Solid beds of halite at 162. 0 ft (0. 3 ft thick) 

and 162. 9 ft (0.2 ft thick).

173.5 9.0 Halite*, colorless. Bedding, if any, destroyed by drilling. Crystals are encased in yellowish-gray (5Y7/2) 

clay. Halite probably formed about 90 percent of 

unit. A little calcite* and gypsum*.

174. 0 . 5 Clay and silty clay, yellowish-gray (5Y7/2); laminar 

bedding. Halite crystals make up about 5 percent of 

core.

205.0 31.0 Halite, colorless. Bedding, if any, destroyed by drilling. Crystals encased in clay.

224.4 19.4 Clay, silty, yellowish-gray (5Y7/2), massive. Beds 

of solid halite* at 211.5 to 212.5 ft, 214.5 to 

215.0 ft, and 220. 5 to 221. 5 ft; a little calcite* and 

gypsum* .

265. 0 40. 6 Halite*; generally colorless or tinted gray or tan by included clay; massive(?). A little gypsum and calcite. This section cored very poorly and the resulting "Core" consists of wafers of halite and piles of

broken halite crystals.

273. 5 8. 5 Clay, silty, to clay; pale greenish yellow (10Y8/2) to 

yellowish gray (5Y7/2); massive. Contains small 

amounts of halite and gypsum; calcareous.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

PANAMINT .DRILL HOLE 3-Continued

D th Unit

/ . \ thickness Description

* ___ (feet)

275. 0 1. 5 Clay,, alittle silt and sand; yellowish gray (5Y7/2) with 

mottled patches of darker material; massive. Calcareous.

330. 0 55. 0 Clay, a little silt, a very little fine sand. Color ranges 

between yellowish gray (5Y7/2) arid grayish yellow 

(5Y7/4); local lenses of pale olive (10Y6/2). From 

275. 0 to 298. 0 ft the color emphasizes the beds (the 

coarser sediments are greener, the finer are more 

yellow); from 298.0 to 330.0 ft the. unit is massive. 

Calcareous, increasing downward.

345. 0 15. 0 Clay, a little silt, a very little fine sand. Colors range 

between yellowish gray (5Y7/2), pale greenish yellow 

(10Y8/2), and pale olive (10Y6/2); average is toward 

pale olive. Color banding but no apparent lithologic 

bedding. Noncalcareous except for bottom ft.

354.4 9.4 Clay, pale greenish-yellow (10Y8/2), massive; very 

calcareous; 1-in. beds of gypsum* at 351.0 and 

352.0ft.

365. 0 10. 6 Silt, calcareous, and gypsum; greenish gray (5GY6/1) 

to white (N9); massive. Megascopic crystals of 

gypsum* (from 10 to 50 percent of core) in a matrix 

of calcareous silt; the calcite content is between 

30 and 90 percent.

375. 0 10. 0 Clay, with pods of calcium carbonate. Dark greenish 

gray (5G4/1) and moderate brown (5YR4/4) mixed 

with some streaks and pods of white (N9), still damp. 

Texture is contorted; may have been bedded.

384.0 9.0 Silt, light greenish-gray (5G8/1) to very light gray 

(N8), massive; very calcareous; a few crystals of 

gypsum up to 4 mm long.

385.0 1.0 Gypsum and calcite, very light gray (N8), massive.

Crystals of gypsum up to 1 mm long. 

395.0 10.0 Gypsum and halite, silty, light greenish-gray (5GY8/1);

massive. Gypsum and halite form up to 90 percent

of core; average is about 70 percent. 

401. 0 6. 0 Clay with pods of calcite*, dark greenish-gray (5G4/1)

and moderate -brown (5YR4/4), still damp. Texture

contorted. Poor core. 

401. 3 . 3 Halite and silt, colorless crystals.

408.0 6.7 Clay, silty, light dusky-yellow (5Y7/4), massive.

Some isolated halite crystals; calcareous. 

412.0 4.0 Silt, grayish-olive (10Y4/2), still damp; massive. May

be cuttings, not core. 

415. 0 3. 0 Clay, silty, light dusky-yellow (5Y7/4); laminar bedding. A little halite; calcareous.

418.0 3.0 Silt, grayish-olive (10Y4/2), massive. May be cuttings, not core.

424.3 6.3 Clay and a little silt interbedded. Dusky-yellow (5Y6/4) 

clay and yellowish- gray (5Y7/2) silt. Bedding of two 

types: one is laminar; the other is about 20 mm 

thick. Section about 90 percent clay. Calcareous.
fin

GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

PANAMINT DRILL HOLE 3-Continued

/ + \ thickness Description

(feet) (feet) __________________________________________ 

449. 3 25. 0 Halite; colorless crystals (usually covered with clay);

massive. A little gypsum* and calcite*. Some beds

of silt included in the core are probably cuttings, not

core. 

450.0 .7 Sand, very fine, yellowish-gray (5Y7/2). Beddingfaint,

about 5 mm average thickness. Well sorted, well indurated. Calcareous. 

454.0 4.0 Clay and a little silt interbedded. Dusky-yellow (5Y6/4)

clay and yellowish-gray (5Y7/2) silt. Well bedded.

Calcareous. Top foot is still damp; presumably cuttings, not core.

456.6 2.6 Silt. Between yellowish gray(5Y7/2), light olive gray

(5Y5/2), and pale olive (10Y6/2); average is toward 

pale olive. Laminar bedding. Carbonaceous partings. Calcareous; salty.

460.0 3.4 Clay and a little silt in upper half grading to silt in 

lower half. Dusky yellow (5Y6/4) and yellowish gray 

(5Y7/2) in upper half; pale olive (10Y6/2) in lower 

half. Entire unit well bedded. Carbonaceous partings. Calcareous.

461. 0 1.0 Clay and a little halite. Clay is dusky blue (5PB3/2), 

still damp. Halite forms about 10 percent of core.

474.0 13.0 Halite*, colorless; tan or gray clay coating on crystals; massive. A 1-in. silt bed at 464. 5 ft. Upper 

two-thirds about 20 percent, clay; lower one-third 

about 2 percent clay.

479. 7 5. 7 Silt and clay, pale-olive (10Y6/2). Bedding 1 to 10 mm 

thick; defined by color banding. Pods of white 

(gypsum?).

485. 0 5. 3 Clay and halite. Clay is pale olive (10Y6/2); halite is 

colorless. Fine bedding. Ratio of halite to clay is 

1 to 1. A little calcite.

531.0 46.0 Halite; a little clay. Halite is colorless. Massive (?). 

A little calcite and gypsum. Top contact is gradational; basal contact is sharp. Core is very poor and 

bedding is not recognizable; the section drilled as if

massive salt.

545.0 14.0 Clay, - yellowish-gray (5Y7/2) to pale-olive (107672).

Bedding is distinct, units 1 to 10 mm thick; some 

partings appear carbonaceous. Calcareous.

555.0 10.0 Silt; yellowish-gray (5Y7/2), darker where core is still 

damp; massive to mottled texture. Fragments of 

halite and gypsum, the percentage increasing downward; calcareous.

556.0 1.0 Calcite and gypsum encased in mud, greenish-gray 

(5GY6/1). Core is about 90 percent crystals.

557.0 1.0 Silt, yellowish-gray (5Y8/1), massive, slightly calcareous. 

559. 5 2. 5 Halite; a little clay. Colorless halite; clay is greenish

gray (5GY6/1). Massive. 

569. 5 10. 0 Clay, yellowish-gray (5Y8/1) to light greenish-gray

(5GY8/1), mottled coloring; generally massive, local

thin bedding; calcareous. 

585.3 15.8 Clay grading down to silt, yellowish- gray (5Y8/1).

Bedding fine up to 10 mm. Calcareous. Fine sand,

576. 0 to 577. 0 ft.
CORE LOGS, OWENS, CHINA, SEARLES, AND PANAMINT BASINS

PANAMINT DRILL HOLE 3-Continued

th Unit '

/? .\ thickness Description (feet) (feet)

590.0 4.7 Clay, yeUowish-gray (5Y8/1) to very pale orange 

(10YR8/2), massive, calcareous.

596. 5 6. 5 Silt to fine sand; yeUowish gray(5Y7/2) to pale olive 

(10Y6/2), patches of white (N9); massive. Pods and 

small lenses of gypsum and halite at 596. 0 ft.

601.0 4.5 Clay, yellowish -gray (5Y8/1) to very pale orange 

(10YR8/2), generally massive, calcareous.

610. 0 9. 0 Silt grading downward to very coarse sand with silt 

matrix, yellowish-gray (5Y7/2) to (5Y8/1), massive, 

calcareous and gypsiferous, from 603.0 to 604.0 ft 

gypsum forms up to 30 percent of core.

624.0 14.0 Silt and fine sand grading down to fine sand, light 

olive-gray (5Y6/1), massive, slightly calcareous. 

Poor core.

624. 3 . 3 Tuff, mixed with very fine sand; very light gray (N8).

Fine bedding defined by black streaks of carbon or

biotite. Very well indurated. 

656.0 31.7 Sand, very fine, yellowish- gray (5Y7/2), massive.

Calcareous.

785.0 129.0 Silt to very fine sand, yellowish-gray (5Y7/2); very 

faint bedding to massive; very well sorted. Calcareous; a 1-ft bed of calcareous silt at 724.0 ft. 

Many flakes of mica, up to 0. 5 mm wide.

794.0 9.0 Clay, silty, yellowish-gray (5Y7/2), massive(?), 

slightly calcareous. Poor core.

795.0 1.0 Sand, very fine, yellowish-gray (5Y7/2), massive. A 

little gypsum; calcareous.

801.0 6.0 Silt; very little fine sand; dark yeUowish gray (5Y6/2). 

Bedding in top ft 1 to 10 mm thick; appears to be at 

an angle of about 60° to the sides of the core; probably a result of drilling pressures.

805.0 4.0 Silt to very fine sand, dark grayish-yellow (5Y7/4), 

massive, very slightly calcareous.

814. 2 9. 2 Silt to very fine sand, dark-yellowish-gray (5Y8/2), 

massive. A little gypsum.

815.0 .8 Silt to very fine sand, dark grayish-yellow (5Y7/4); 

faint bedding; slightly calcareous.

829. 3 14. 3 Silt to very fine sand, yellowish-gray (5Y7/2) to darkgrayish-yellow (5Y7/4). Some faint laminar bedding 

but generally massive. Slightly (about 0. 5 percent) 

gypsiferous; calcareous; flakes of mica common.

835. 0 5. 7 Clay, gypsiferous, silty, dark grayish-yellow (5Y7/4), 

mottled coloring. Gypsum forms 5 to 20 percent of 

core, average 10 percent; found as bladed crystals 

up to 10 mm long. Very slightly calcareous.

844. 5 9. 5 Clay and a little silt. Dusky-yellow (5Y6/4) clay and

yellowish-gray (5Y7/2) silt. Massive. 

845.0 .5 Silt, gypsiferous (?); very light greenish gray (5GY9/1),

lenses of white (N9). 

855.0 10.0 Sat, greenish-gray (5Y7/1). Locally shows faint bedding up to 10 mm thick but is generally massive.

Lenses of anhydrite* and gypsum*; very slightly 

' calcareous*.
62 GEOLOGIC INVESTIGATIONS IN MOJAVE DESERT REGION

PANAMINT DRILL HOLE 3-Continued

Depth Unit

if «4.\ thickness Description

(feet) (feet)__________________________________________

865.0 10.0 Clay, silty, yellowish-gray (5Y7/2); massive, generally, with local laminar bedding; calcareous, a little 

gypsum*.

875.0 10.0 Core lost; estimated to be the same as previous 10 ft.

895.0 20.0 No core; solid bit used; the material is presumably 

similar to that at 865.0 ft.

913.0 18.0 Clay, very little silt and very fine sand; dark grayish 

yellow (5Y7/4). Very well bedded; laminar to 20 mm 

thick in upper part, grades down to massive. Black 

partings of carbon or biotite in upper part. Calcareous, a little anhydrite (?)*.

914.6 1.6 Clay; yellowish gray (5Y7/2), to light olive gray 

(5Y5/2) in lower part. Lenses (up to 1 mm thick) 

of biotite(?). Excellent laminar bedding. Calcareous.

915.0 .4 Sand, fine, dusky-yellow (5Y6/4), poorly sorted, massive.

931.4 16.4 Silt to very fine sand, yellowish-gray (5Y7/2). Massive in upper half grading to very faint bedding in 

lower half. Calcareous; gypsiferous.

935.0 3.6 Silt, yellowish-gray (5Y7/2). Excellent laminar bedding; partings of black biotite(?). Calcareous.

945.0 10.0 Clay, silty,to silt; light greenish gray (5GY8/1); massive. Gypsum at 937.0 ft.

965.0 20.0 Clay to silt, yellowish-gray (5Y8/1) to light olive-gray 

(5Y6/1). Fine bedding; laminar to 15 mm thick. 

Some partings of biotite silt. Small lamellae of 

gypsum (?) and anhydrite*.

985.0 20.0 Silt with thin beds of gypsum(?) and anhydrite(?); 

yellowish gray (5Y8/1). Silt beds are well sorted 

and well indurated. Gypsum (?) and anhydrite (?) 

form about 10 percent of the core. No core recovered from 965 to 973 ft but drilling characteristics 

indicate a well-indurated material similar to the recovered core.

995.0 10.0 No core; drilled as il very hard material, like unit 

above.

U. S, GOVERNMENT PRINTING OFFICE: 1957 O 409163