STATE OF CALIFORNIA EARL WARREN, Governor DEPARTMENT OF NATURAL RESOURCES WARREN T. HANNUM, Director DIVISION OF MINES FERRY BUILDING. SAN FRANCISCO 11 OLAF P. JENKINS. Chief SAN FRANCISCO SPECIAL REPORT 13 NOVEMBER 1951 GEOLOGY OF THE SALINE DEPOSITS BRISTOL DRY LAKE SAN BERNARDINO COUNTY, CALIFORNIA By HOYT S. GALE Prepared in cooperation with the United States Geological Survey Digitized by the Internet Archive in 2012 with funding from University of California, Davis Libraries http://archive.org/details/geologyofsalined13gale GEOLOGY OF THE SALINE DEPOSITS, BRISTOL DRY LAKE, SAN BERNARDINO COUNTY, CALIFORNIA! By Hoyt S. Gale OUTLINE OF REPORT Tage Introduction •{ Location and environment •{ Physiographic history 4 Chemical deposits in the Bristol Basin "» Gypsum •"> Sodium chloride (> Calcium chloride Celestite 10 Appendix 10 Logs of test holes on Bristol Dry Lake 10 Illustrations Fh;i"kf. 1. Air photo showing Bagdad Crater and Recent flows of basaltic lava 4 2. Air photo showing the Salt Lake and excavations— 7 1'i.atk 1. -Map of Bristol Dry Lake area 8-9 INTRODUCTION The writer has worked on the saline deposits of Bristol Dry Lake intermittently since the summer of 1916. At that time, he had charge, for the United States Geological Survey, of an exploratory campaign in search of potash in the saline deposits in the western part of the United States, including the location and drilling of a series of 100- to 200-foot holes at selected localities. One or two holes were drilled on Bristol Dry Lake, south of Amboy. During the summer of 1942 L. F. Noble and the writer, for the Geological Survey, engaged in a review of salt deposits suggested as available for use at the plant of Basic Magnesium, Inc., near Las Vegas, Nevada. On July 1, 1942, a visit was made to the salt deposit at Bristol Dry Lake in company with Messrs. J. W. Lowman, assistant to Howard P. Eells, Jr., president of Basic Refractories, Inc. ; W. F. Biedebach, president of Cali- fornia Salt Co. ; L. F. Bayer, engineer of Basic Magne- sium, Inc. ; and Kenneth Staples, superintendent of the California Salt Co. operations on Bristol Dry Lake. A brief report of this examination was written and trans- mitted from Las Vegas, Nevada, to Albert E. Bassett, Chief of Administrative Section, Defense Plant Corpora- tion, Washington, D. C, on July 3, 1942. In September 1942 the writer again visited Bristol Dry Lake and made a small-scale plane-table map showing the general outline of the various parts of the saline deposits there and their relation to the playa and basin. Subsequently, various data have been collected con- cerning this basin and these deposits, including a series of well logs from exploratory drilling that was done on these deposits by the Metropolitan AVater District of Southern California in the summer of 1939. The accom- panying larger-scale map of these deposits is compiled from air photographs of the U. S. Army Air Forces, Gen- eral Land Office survey data, and data from the Metro- politan AVater District and California Salt Co. This information has been gratuitously contributed bv these v Published by permission of the Director, U. S. Geological Survey. Manuscript submitted for publication February 1951. * Geologist, U. S. Department of the Interior, Geological Survey. organizations to assist in the present official investigation of these deposits; and permission has been obtained spe- cifically to use this information for publication. Location and Environment Bristol Dry Lake is southeast of the central part of San Bernardino County, California. It is one of a series of playas or basin bottoms that lies along the south side of the main line of the Santa Fe Railroad from Bagdad to Cadiz, and south of the branch line that leads off from Cadiz to Parker and Phoenix, Arizona. Amboy is a small settlement and railway station on the northern edge of the Bristol Lake playa, 226 miles by rail from Los Angeles and 84 miles from Needles. It is on U. S. Highway 66 and is the junction point for a highway that leads south to Dale and Twenty-nine Palms. Bristol Dry Lake lies in a broad valleylike depression toward which the surface drainage of storm waters flows from adjacent mountains and slopes, and from which there is no exterior drainage. To the north and northeast are the narrow, peninsulalike ranges of the Bristol and Marble Mountains. On this border of the Bristol Dry Lake basin these mountains are composed largely of granitic rocks (granodiorite or quartz monzonite). They are pre- sumed to be Jurassic in age, as they are associated with marble and other metomorphosed Paleozoic sedimentary rocks. At the south end of the Marble (also known as Iron) Mountains, near Siam and Cadiz, some of the granite is conformably overlain by quartzite and lime- stone that have yielded fossils of Cambrian age. Thus, some of the granite in this region is older than the fossils and is undoubtedly of pre-Cambrian age. 1 To the northwest the Bristol Dry Lake basin is bounded by the rugged surface of the Recent flows of black basaltic lava that poured over the surface of the basin and separated it from its previous extension far to the northwest, This lava seems to have erupted from the interesting volcanic crater and surrounding cone that stands a few miles southwest of Amboy, known as the Bagdad Crater. This lava which divides the present basin of Bristol Dry Lake from a western arm now called Bagdad Lake was poured out in very late geologic time, as it lies upon the surface of the present playa clays. An air view of this feature is shown in figure 1. On the south the Bristol basin is closely bordered by Bullion and Sheep Hole Mountains and the relatively steep alluvial slopes that front the ranges. The barrier that partly crosses the Bristol trough on the southeast consists of two somewhat diverging ridges that expose basement rocks in a series of low ridge sum- mits, mostly buried by drift sand. This divide has not been examined in detail, although features that can be seen from a distance have been noted. The air photos bring out some suggestions as to the structure, showing the blanket of dune sand around the rocky summits, sloping northward and meeting the alluvial slope that comes 1 Darton, X. H., Discovery of Cambrian rocks in southeastern California: Jour. Geology, vol. 15, pp. 470-473, 1907. (3) Special Report 13 C Amb °y Bagdad Cro/er -( Floi'RK 1. Air photo showing Ba« .1 Crater and Recent flows of basaltic lava southwest of Ambov. • low,, fro,,, the northeast between Marble and Ship Moun- tains. J l,e junction of these two opposing slopes seemingly '"'■'"V 1 " '"distinct cha 1 that skirts the foot of The sand dune area. A considerable physiographic description of this area is given in a comprehensive paper bv David G Uiompson,- who considers Bristol Drv Lake to be con "•'••ted with Cadiz Dry Lake by a reported well denned c,,ai ' ,hi,t Possibly drains fro.,, Cadiz to Bristol Thus tlle two ''asms belong to a single major drainage unit. Physiographic History This area is part of the Basin and Range province of the southwestern United States, the topography of which is to a large extent determined by faulting. The trouffh- ike valley ,n which lies Bristol Dry Lake shows a morTor less distinct northwest trend, which is probablv related to taulting in the older rocks underneath the present surtace. The original trough or depression is filled to undeter- mined depths with the sedimentary deposits of rock detri- tus swept down alluvial fans from the slopes of the bor- dering mountains or brought into the basin alon« the Saline Deposits of Bristol Dry Lake channels of former streams that traversed the region. The entire depression is still in the process of being filled with gravel, sand, and clay, which are swept over the lower parts by storm waters. The present playas or dry lakes are low spots along the main trough, divided by the spread of alluvial fans, aided in this ease by the lava flows, and possibly by some late warping or faulting. Surface waters usually flood only the lower parts of these basins. They deposit the load of coarser detritus on the bordering slopes and carry none but the finer sediments to the playa bottoms. An earlier stage of this historical record has been suggested by Darton, 3 who thought that the depression that" contains Bagdad, Bristol, and Cadiz Dry Lakes prob- ably resulted from tilting of an earlier (Pleistocene) main stream valley. Although he did not mention the possible origin of such a valley, it might have been part of a former channel of overflow from the Mojave River to the Death Valley drainage system, whereby those waters might have passed over into the Colorado River drainage. The present divide at Ash Hill, between Bagdad and Ludlow, is now blocked by a flow of basaltic lava, somewhat like that surrounding the Bagdad Crater. This pass, 165 feet higher than the railway station at Ludlow, has a present eleva- tion of 1,944 feet above sea level, where the railroad crosses on the surface of the lava. It is not known whether the Pleistocene lakes that occupied Death Valley ever approximated this elevation or not, but if they did most of the traces of such inundation have long since been removed by erosion. If the stages of development of the present land forms were more clearly understood, some clearer concept might be had of the deposits to be expected at depth within these basin areas. The present drainage pattern across the nearly flat surface of the Bristol playa shows a certain number of features that may be significant of underlying geologic structure, and may have some relationship to the distribu- tion of deposits iii the playa sediments. An attempt has been made to trace these features from the air photographs as shown on the map presented with this report. Drainage that enters the playa at the northwest corner near Amboy is seen to divide, as though by distributary channels, at the head of a low flat alluvial fan slope, a mile or two south of Amboy. Thence one channel skirts the foot of the Bag- dad lava* flows, going southward into the western end of the so-called Salt Lake, which covers the lowest part of the Bristol playa. Another channel meanders eastward and then on a fairly well defined course to the southeast, until interrupted by the low transverse range of older rocks that terminate* the Bristol Basin on the southeast, where it crosses into the lower trough of Salt Lake-. CHEMICAL DEPOSITS IN THE BRISTOL BASIN Some dissolved salts are carried by all surface and ground waters. The constituents of these salts vary with the kinds of rocks over which the waters drain. When the infrequent storm waters spread in a thin sheet over the flat-floored playas they become still and their suspended sediment settles out. If the waters of the playa are saline, the dissolved salts may help to bring the colloidal part of the sediments down, forming a dense muddy surface. ••'Darton N H., and others. Guide book of the western United States. I'art C, the Santa Fe Route : U. S. Geol. Survey Hull. 613, p. 153, 1 9 1 r. . When the shallow lakes finally become dry, the salts are deposited on the surface, more or less mixed with the fine silt and mud, or as a crust of salts. A body of brine com- monly permeates the subsurface sediments in association with such deposits. The relatively insoluble gypsum (calcium sulphate dehydrate) is usually among the first of these dissolved constituents to precipitate. Sodium chloride (common salt) is generally a principal constituent of such saline deposits. In volcanic regions such waters usually contain much sulphate and carbonate, and at places borate. The less soluble materials tend to precipitate out. Sodium chloride remains abundant in the residual solutions and forms a considerable part of the final saline residues. The substances thus accumulated in the Bristol Basin that have proved to be of commercial interest are: (1) gypsum, (2) salt or sodium chloride, (3) calcium chloride, and (4) celestite. No doubt much calcium carbonate was deposited also from these solutions, but it is not known to be of value. The industrial activity at Amboy is closely related to the Bristol Dry Lake playa and its deposits. A plaster mill was formerly operated on the north edge of the playa, about 2 miles southeast of Amboy. At present the most active operation in the vicinity is the salt mill, at a rail- road siding called Saltus, about K miles east of the old plaster mill. The salt is derived from an area near the center of the Bristol Dry Lake playa about 4 miles south- west of the mill. A third operation devoted primarily to production of calcium chloride centers at a group of solar vats and a crude calcining plant on the floor of the playa 6 miles due south from Amboy. Amboy serves as a supply station for the mines and prospecting operations that are active from time to time in the adjoining mountains. Gypsum Gypsum (calcium sulphate dehydrate) occurs in irregular bodies or layers included within the sediments that make up the playa. It is conspicuous at places, on or near the surface, around the borders of the bare mud area that is usually classed with the playa. It forms a white crusty surface with protruding lumps composed of the harder masses of this mineral. This gypsum was described by Iless 4 while these deposits were under operation by the Consolidated Pa- cific Cement Plaster Co. According to his account the gypsum was found chiefly along the front of the basaltic lava flow at the northwest border of the playa. The dune- like gypsum is said to have been blown into small drifts across the tongues of the lava. Excavated for delivery to the plaster mill, the gypsum was found to extend to a depth of 6 to 8 feet and possibly deeper. Below that depth ground water interfered with excavation. The cleanest and purest material is a spongy white mass, granular to more coarsely crystalline, that is easily broken into blocks or crushed. The top is usually somewhat dirty. At places a light volcanic ash, 1 foot or more in thickness, covers the gypsum. Formerly much gypsum was produced and shipped from this deposit. About 1,800 acres of claims patented as gypsum land is now held by the United States (iypsuin •Stone K W and others, Gypsum deposits of the I'nited States : II. S. Geol. Survey Bull. 697, pp. 81-X2, 1920. (i Spei i ai. Report 13 I " . which is situated in a belt around the northwest bor- der of the playa. The old plaster mill, where the material was calcined and prepared for shipment, is situated in set' in. T. :>.Y. R. 12 E., about 2 miles southeast of Amboy. These operations were discontinued about 1924 or 1925. Darton r ' reported that a 700-foot well was drilled for water at Amhoy, on the upper border of the plava. It penetrated chiefly sand and gravel, with some salt 'water near the top. hut encountered a deposit of pvpsum at a depth of 70 feet. Sodium Chloride Sodium chloride (common salt) occurs not only as an incrustation on the surface, such as is seen in the area <>l the Salt Lake during dry seasons, but also as a series «»l flat tabular bodies interbedded with the sediments that underlie the playa, and as scattered crystals within certain layers of the sediments, extending to an undetermined depth. Present Surface Deposits. The so-called Salt Lake covers the lowest part of the Bristol Drv Lake or playa. Tins depression is a troujrhlike area that lies along the southern edge of the main playa, and consists of a rather distinct belt about 11 miles wide with roughly parallel sides, trending about S. 60° E. The lowest part of this belt is obviously the "sink" of the present drainage sys- tem. This sink is clearly an area intermittently flooded by storm waters and is normally marked by a surface layer of white crusted salts. The writer attempted to map this area bv plane-table and traverse methods in 1942; since then, air photographs prepared by the U. S. Army Air Forces in 1943 have be- eoinc available, adding much significant detail concerning these deposits, their topography, and suggestions as to some geologic structure. The photograph centering over the Salt Lake and the trenches dug bv the California Salt Company (fig. 2) shows clearly the area of the white crusted salts and a narrow bordering gravish zone sup- posed to he the mark of temporary higher flood level This troughlike area with distinct trend marks the southern border of the whole playa and suggests faulting along its south edge. It terminates along a remarkably st/aight front with trend of X. 30° E., suggesting closure oi the Bristol Basin by cross-faulting at the southeast- ern end. The crust of white salt on the surface of this deposit is relatively thin, overlying mud that is frequentlv very suit and seems to he permeated by a salt-saturated' brine -Mud salt exists there, and some of it has been recovered as a by-product obtained by evaporation of the brine for Production of a liquor rich in calcium chloride These operations are referred to under the heading calcium chloride. I is possible that a considerable supply of com- mercial salt might he obtained from this source', but this probably depends on the practicability of recovering the salt Iroiu tlussolt "round. The area pf bare mud surface that is included in what is called the playa consists of very saline mud or sediment <"' the surface, lumpy and irregular in detail, but almost level m genera] appearance. This playa extends from Amboy about 8 miles south, as seen alongside the road to Dale and rwenty-nme Palms. A similar brownish muddy surface extends for at least (i or 7 miles to the southeast I '.o ton, X. II., op. cit., p. 154. from the Dale road. It is flat in appearance, a more o less typical playa deposit. This surface has a gentle slopt southward toward the lowest part of the basin and tht salt lake ; the slope is shown by shallow drainage channel' that can be traced on the air photos. Main Commercially Worked Salt Bed. The salt that is being produced commercially in the Bristol Dry Lake area comes from a bed of rock salt that lies at shallow depth beneath this brown playa area. This is the upper most of a series of beds of crystalline "rock" salt inter- calated with playa-type sediments, shown by borings to extend more than 100 feet in depth, at least in parts of the basin. This bed of rock salt is nearly horizontal and appar- ently represents a bottom deposit in a shallow saucerlike basin that existed at the time the bed was formed. The salt is covered only by overburden composed of soft clay, mud or silt, which is about the same thickness as the salt and varies with the thickness of the salt that lies beneath it This salt bed was formed by crystallization out of a shallow body of brine in a comparatively late epoch of the Bristol Dry Lake deposition. The salt bed is thickest at the deep- est part of the basin. That former basin now seems to have been tilted slightly toward the south, and occasional sur- face flood waters that pass over the area and the mother liquor brine from which the salt was deposited are partly drained southward away from this bed. Thus the topmost bed of salt in these deposits is more accessible than it would be if it were wholly submerged in brine as in the lower parts of the present basin, and also more accessible than any of the lower beds that might be reached in deeper excavations at the present workings. The only salt that can be mined with the equipment now in use on the deposit is this topmost bed. It is a thin lensmg layer, 6 to 7 feet thick in its thickest part, accord- ing to the available records, and tapering to thin ed^es around the borders of its particular basin. The outline of this area is drawn on the accompanying index map (pi. 1) ; but the outline as drawn is based on scattered data and probably is not exact. Only the portion of this bed that ranges from about 3 feet to a maximum of 7 feet in thickness at the center is included in the area thus out- lined ; this area is estimated to be commercially important at the present time. The salt that is mined is an open-textured mass of interlocking crystals of halite. Much of it is clear material but some of it contains included mud. The cubic form of the halite ■crystals is obvious in material blasted from the deposit but there has been some re-solution, leaving rounded cavities in the salt crystals. Mud, which was originally included between the crystals or was infiltrated through open spaces between the crystals, is irregularly distributed throughout the salt bed. Most of the salt shipped from the Bristol Dry Lake area is produced by the California Salt Company (for- merly called the California Rock Salt Company) This concern ships salt of various grades from its plant at the railroad siding on the Santa Fein sec. 11, T 5N R 12 E It also produces and ships calcium chloride, which is now considered of more commercial importance than the salt he output of salt from Bristol Drv Lake was com- puted at about 220,000 short tons shipped in 1942 but according to the latest figures (1950) the rate has'now Saline Deposits oe Bristol Dry Lake Figvrk 2. Air photo showing the Salt Lake and excavations. Superimposed land survey net is approximate. declined to about 120,000 tons a year. The Basic Mag- nesium plant near Las Vegas, Nevada, which formerly required about 150,000 tons yearly, now uses about 60,000 tons; and the Metropolitan Water District of Southern California, reported as using about 8,600 tons in 1942, is now consuming this salt at the rate of about 40,000 tons annually. According to Bulletin 142 of the California Division of Mines, published in 1949, salt (sodium chloride) from San Bernardino County, California, amounted to 150,293 short tons in 1947 ; the greater part of this came from the Bristol Dry Lake deposit. Some salt is now produced from a deposit at Dale, south of Bristol Dry Lake, the output being shipped by way of Amboy. Also a moderate amount of salt is snipped from the deposit at Searles Lake, in the northwest corner of San Bernardino County. The California Salt Company mines its salt from trenches near the center of the Bristol playa, but north of the Salt Lake. According to present practice the surface layer of saline mud ("overburden") is scraped away with power shovels. The shallow bed of rock salt is reached at a depth of about 3 to 7 feet. The thickness of the salt also ranges from 3 to 7 feet, the thickness of overburden at any one location reportedly being just about the same as the salt underlying it. When the salt is uncovered it is drilled with an auger bit mounted on a small truck or Special Report 13 carriage, and broken with dynamite. The broken salt is thru lifted by dragline dredge to tram cars on a narrow- track that leads across the flat to the salt mill ap- proximately 4 miles away. The original excavations for this salt were iti the SE^ sec. 28, T. 5 N., R. 12 E., which is patented property owned by the California Salt Com- pany. Later excavations have extended these workings into the \.l sec 33 and the NW£ sec. 34 adjoining the original excavations. At the mill the rough broken salt is put through a crusher, and is then washed into screw-elevator troughs (log-washer), wherein the salt is lifted and agitated against down-flowing streams of a normal-temperature brine obtained from shallow wells at the plant. The bulk Of the production is thus a coarsely broken crvstal salt. 1 'ntil 1942 most of the salt mined had been taken from the patented ground (SE* sec. 28, T. 5 N., R. 12 E.) and from a narrow strip extending southwestward into the N \V 1 sec. 33. A very small part of the shallow salt bed had been mined out at that time. These claims were at first located for calcium chloride under the mining laws of 1908-9; from the time work was started in 1910 until about 1918 the salt was discarded. The claims were taken over by the California Rock Salt Company in 1921 and by the present operators, the California Salt Company, in 1923. There is still a considerable reserve in this one bed. The approximate area as outlined on the map (pi. 1) is indicated as underlain by salt of the shallow bed, which ranges in thickness from a maximum of about 7 feet to about 3 feet at the border shown on the map (assumed average about 5 feet). Without systematic test boring records at hand it does not seem feasible at present to attempt to state this acreage in more definite terms. The genera] estimate was made in 1942 that the area thus out- lined should maintain operations using 40 acres per year for at least 10 to 20 years, and probably much longer than that. Estimates of the tonnage of salt contained in this bed were based on the assumption that the cellular coa rsely crystalline salt weighs at least 75 pounds per cubic toot of the deposit as it exists in the ground. Plant opera- tion figures indicated an average of about 60 percent recovery after crushing, grinding, and washing. This indi- cates about 1.000 tons of crushed and washed salt, such as thai shipped to the Basic Magnesium plant at Las Vegas recovered per acre-foot of the original deposit Thus a 40-acre tract whose thickness of such salt is 5 feet is com- puted to yield approximately 200,000 tons. A certain amount of salt has been saved and shipped from other parts of the deposit, but this production has been sporadic. It is possible that salt might be recovered commercially from the deeper deposits in Bristol Basin but for the present such recovery does not seem feasible' Deeper Salt Beds. The existence of rock salt and more or less saturated brines at various depths within the playa has been shown by exploratory drilling in sev- er^ parts of the deposit, though the writer knows of no such tests having been made in the area covered by the Bait Lake. A considerable series of shallow holes has been drilled by the salt company and the calcium chloride <>P"'-a.ors, Chiefly ,„ the search for commercial amounts " f h ''""' '•";!' >" calcium chloride. A series of 19 test holes was drilled during mid-summer of 1939 by the Metro- pohtan Water District of Southern California. The loca tions of these holes are shown on the accompanying map (pi. 1). Although these tests were confined to certain properties that were then being investigated, they are rather well distributed over the main or lower part of the playa deposits, and give a good indication of the salt beds that lie below the surface within the limits of the depths thus reached, the maximum being 152 feet All information about subsurface deposits in the plava is necessarily obtained from these data and the shallow excavations by the salt company. All logs of the holes drilled by the Metropolitan Water District are quoted m full in an appendix at the back of this report. The gathering of soluble constituents by surface and perhaps ground waters, and the concentration of them in the lower parts of Bristol Dry Lake basin by evaporation of the waters on the surface have evidently been goincr on for a long time. Hence the basin as a whole must have been formerly much lower or deeper than it is at present The deepest well reported in this basin is one that was drilled tor water supply at Amboy, which is somewhat outside of the main playa or pan of saline accumulation Hole No. 12, drilled by the Metropolitan Water District lies about a mile east of the indicated limit of the com- mercially workable shallow salt bed, but it seems to be u U l ?u f uT With the lon S axis of the depression in which that bed was laid down. The log of this 152-foot hole shows five beds of rock salt, distributed at intervals within the sediments. There may be other salt beds and perhaps gypsum and other materials below this depth Besides the above-recorded salt beds, which total 28 feet in thickness, several layers of clav contain a lar<*e per- centage of salt. The sediments were reported as brown green, and gray clays, in horizontal or nearly horizontal layers. Thin beds of light volcanic ash were 'recorded at a depth of about 75 feet, which might serve as a marker zone for correlation with other holes drilled nearby As very little water entered the hole at anv depth," it is assumed that no sand or coarse sediment free from clav was encountered. The drill hole referred to above is one of a series that lies near the foot of the slope leading down from the north within the bare mud surface of the plava. Five holes are ranged from northwest to southeast within this belt. Those to the northwest (Nos. 16 and 17) are perhaps at or beyond the limit of the more important salt beds (see pi. 1). Omitting No. 16, in which no rock salt was recorded, a summary of the hard or rock salt beds found m the other four holes is given in the following table. 1 hese results are quoted in tabular form because accurate surface elevations at the holes are not available. The loca- tions of these holes are shown on the accompanying map _ A group of four holes was drilled in sees. 25 and 36, T. o N., R. 11 E., a little more than a mile northwest from the west end of the Salt Lake. These reached a maximum depth of 50 feet, and the two of these that lie nearest to the lake bottom showed beds of hard salt between the depths of 22 and 31 feet. Again it is difficult to suggest exact correlations between the indicated salt beds. Per- haps leveling data for ground elevations at the well loca- tions would help. mop from o portion of sheet No 67 ol the base mop ol the Metropolitan Woter District of southern California, with dato odded Geology by Hoyt S Gale 1942 MAP OF BRISTOL DRY LAKE AREA, SAN BERNARDINO COUNTY, CALIFORNIA Contour Interval 100 feet cai tin gra pr tli is pa in or cr (1 ag br of th fr N b< lo 1! al o b 1 1!- r a a r a Saline Deposits of Bristol Dry Lake Depth and thickness, in feet, of four test holes of Metropolitan Water District No. 17 No. 18 No. 19 No. 12 Depth Thick- Depth Thick- Depth Thick- Depth Thick- (in ness (in ness (in ness (in ness feet) (in feet) feet) (in feet) feet) (in feet) feet) (in feet) 13-13H w 19-19J4 X 19^-20 w 25-25^ 1 29-34 5 36^-37 H 37-38 1 40-42 2 43-43 H H 40)^-50 9H 42-46 58-65 77-84 112-121 4 7 7 9 50 (Total) 50 (Total) 52 (Total) 152 (Total) Less difficult to correlate is a series of three test holes, all in sec. 9, T. 4 N., R. 12 B., ranging from the middle of the south edge of the Salt Lake to a location near the middle of the east side of the section. Although all were less than 100 feet in depth, they record a series of beds of hard crystalline salt as follows : Depth and thickness, in feet, of three test holes of Metropolitan Water District No. 3 No. 4 No. 5 Depth (in feet) Thickness (in feet) Depth (in feet) Thickness (in feet) Depth (in feet) Thickness (in feet) 7-9^ 13-14 19-23 41-43 2)4 1 4 2 8-10 18-20 23-26 45-48 70-72 H 2 2 3 3 2M 19-20 1 50 (Total) 97 (Total) 53 (Total) Even these holes, situated on an almost level plain surface and less than half a mile apart, do not correlate very precisely, but this lack of precision may be due in part to unavoidable imperfections in a drill log of this sort. The thicker beds of rock salt shown in these tests lie at depths of about 20 feet or more, and it appears that it would not be practicable to remove such a mass of over- burden by open-cut mining. A leaching method seems to be the alternative, if a sufficient supply of water is available. Brine of high concentration was found in holes Nos. 3, 4, 5, 7, 8, 9, 11, 13, 14, and 15, which might be pumped to the surface and evaporated in solar vats. Assuming the necessity of handling 1,000 gallons of such brine to pro- duce 1 ton of salt, a supply of concentrated brines suf- ficient to support a large-scale operation could probably not be obtained. Calcium Chloride Brine, in various stages of concentration, permeates the sediments and salt deposits of the Bristol Dry Lake playa, and at places this brine is rich in calcium chloride. This is somewhat unusual among desert saline deposits. For the most part the brine appears to be a residual con- centration of the "mother liquor" type. In at least two places crystals reported to be calcium chloride are said to have been found scattered in clay at some depth within the playa. Dana reports calcium chloride (CaCl 2 ) occur- ring in nature at other localities as the mineral hydrophi- lite, associated with halite, anhydrite and gypsum, in cubic crystals, as a crystalline or mealy incrustation. Dana also reports a hydrous calcium chloride (CaCl 2 -6H 2 0), which is produced artificially as hexagonal crystals. It also occurs as a double salt with magnesium chloride (taeh- hydrite). The brine found at shallow depths in and near the Salt Lake in the lowest parts of Bristol Dry Lake playa is rich in calcium chloride. The original location of mining claims for calcium chloride was in 1908 and production was begun in 1910. At various times during 1920, 1921, and 1922 a group of mining claims called the Calcium Chloride Group was filed by X. H. Hollar and associates. Other claims of divergent interest were located subse- quently in adjacent areas. For some time it has been con- sidered that the calcium chloride was concentrated mostly in an oval area centering more or less on the Salt Lake ; some maps of this area show this by a definite outline, dis- tinct from the area underlain by the commercially worked salt bed. It has now been shown that the area containing salt beds is by no means distinct from that containing the calcium chloride brine. In fact the California Salt Com- pany has now become the principal producer of calcium chloride in this district, using brines obtained from pits of their salt excavations or wells to the east and north- east of their salt mining operations. Drilling by the Metro- politan Water District developed some brines in subsur- face strata that carry high concentrations of calcium chloride as well as salt, locally along the outer borders of the Salt Lake basin. Bulletin 142 of the California Division of Mines lists four operators as producers of calcium chloride from the Bristol Dry Lake area, giving their addresses as Amboy. The California Salt Company (the former California Rock Salt Company), now stated to be the main producer, ships the concentrated brine as such and supplies the brine to Hill Brothers Chemical Company, who operate a flak- ing plant on the California Salt Company property. The Desert Properties Company, operated under the manage- ment of Frank Thomas, controls the old calcium chloride plant in the SEi. sec. 32, T. 5 N., R. 12 E., and adjoining ditches and ponds. This represents a part of the former "Hollar" property, taken over under the Thomas man- agement in 1939. The so-called National Chloride Com- pany is understood to be another portion of that group. Both are understood to be inoperative at the present time (1950). In a general way operations at the Desert Properties Company have been described ,! as follows: "Brine containing both sodium chloride and calcium chloride in solution collects by drainage into ditches dug into the surface of the Salt Lake area, flowing to the vicinity of the calcining plant along the Amboy to Dale highway as that road crosses the Salt Lake. At the plant the brine is pumped into a solar pond, where it con- centrates by evaporation from about 10° Kaume (specific gravity about 1.15 at 60° F.) to 36° Be\ (specific gravity 1.33 at <><>" V.) or more, whereby the sodium chloride drops out. The residual liquor is then rich in calcium chloride, and this furnishes the liquid form in which the product is marketed. The so-called flaking process is a further dehydration by heat in a furnace, which has been practiced at times as required." " Personal communication from Mr. Frank Thomas. Speciai, The problem of origin or immediate source of the calcium chloride in these brines is often mentioned bv the operators on this deposit. Local authorities are inclined to adopl the hypothesis that calcium ehloride is derived from some source deep seated in these deposits and therefore may be assumed to be replenishing the stocks that arc drawn from the surface in commercial operations. Hudson and Taliaferro 7 discussed the origin of cal- cium chloride waters in general, giving numerous refer- ences. It seems difficult to apply any of their theories to the accumulation of calcium chloride at Bristol Dry Lake be best suggestion would seem to be the common abun- dance oi chlorine (and fluorine) as well as sulphur in ex- halations ot fumaroles and volcanoes, gases presumably derived from a magmatic source. These volatile elements may have com,, from depth along with the lava of the Bagdad Crater flows in quantities sufficient to have pro- duced both gypsum and calcium chloride bv reaction with calcium carbonate, which is an abundant constituent of late alluvial deposits in this area. As the Bagdad eruption was of Recent to possibly late Pleistocene age, this hy- pothesis seems to indicate that most of the calcium chloride was formed about that time, and is probably included m the upper part of the alluvial and playa sec- tion. 1 he ( ahfornia Salt Company drilled 52 w*ells in the area of their salt deposit, obtaining calcium chloride from zones at various depths, but always losing- the cal- cium-chloride-rich brine below the depth of 32 feet An analysis, reportedly by Smith-Emery Company of io°?n ^ I Stat6d t0 be of a sam P le collected in August 1940, from the vats of the Desert Properties Company and therefore assumed to have been of the concentrated mother liquor, is quoted as follows : Calcium Chloride Produced at lirislol Dry Lake Calcium chloride (CaCl 2 ) _ 48 70 Sodium (and potassium) chloride 49 Magnesium chloride < M^CIs) 0S0 Sulphates Carbonates " one Borates . race trace Total as determined ~4949 r a n Th Ru " hemic l al anaI - vsis is probably of crude l.aLl,-blioO, such as produced by evaporation of the brine. One of the samples of brine collected during- the drilling of test holes by the Metropolitan Water District is reported to have shown the following composition by analysis.- J Brine from Hole Xo. 3 (analysis by Carl Wilson) Percentage statement Calcium (Ca) 25 3 Magnesium (Mg)__ j'i Sodium i\a) ' 2 3 fi Bicarbonate (HCO a )_. ~iw!- Chloride (CI) 4 ;,i' smphate (so.) ::::::::: oil Total 100.00 This hole was drilled at the south edge of the Salt Lakearea, about 200 feet southeast of the northwest cor- from ]^^"^i^^^^ r Sl^-r^!r m ^lortde waters Petroleum Geologists Bull, vol 9? no? 7? PP. mc .T.'ms.'""- ^"^ Report 13 ner of sec 9, T. 4 N., R. 12 E. As reported, very little wate entered during the drilling;, but the hole filled to withii 4 feet from the surface in a 12-hour period followin- completion of the drilling. The hole reached a total deptl of 50 feet, but it would be difficult to say from what lave, the brine came. Similar samples of brine were collected from othei Metropolitan Water District holes. Of these, three othei i samples were tested, namely Nos. 7, 11 and 13 Thes brines carried only a third to a half as much calcium a< I that cited above. Celestite Celestite (strontium sulphate) is found on or near the surface in muds, particularly along the south border of the playa. At one time a few tons of these rounded nodular potatolike masses were gathered by plowing the surface and picking up the lumps by hand. There does not seem to be a large demand for this material at the present time. The celestite in the nodules examined is milk-white, minutely crystalline, and without concentric structure! Although these balls appear to have no nucleus, they look like concretions, suggesting that the strontium was segre- gated as sulphate, perhaps by some special shallow ground water conditions at the time they were formed. The dis- tribution of these nodules is related more to the nearly horizontal bedding of the playa sediments and chemical precipitates than to any apparent source in waters issuino- from depth. ° Celestite seems to have a tendency to form as balls or lumps elongated parallel with the bedding of sediments within which they are commonly found. Shale crowded with these spherical lumps is found in tilted Tertiary beds in the Avawatz salt area at the south end of Death Valley At the same locality are other beds of more solid celestite that seem to have been deposited as sedimentary or chemi- cal precipitates, interbedded with shales of Tertiary a"-es similar to much of the gypsum or anhydrite that occurs in this region. However, celestite also occurs as veins fol- lowing and cross-cutting bedding- in shale and probably other sediments, examples of which have been noted by the writer in the Tertiary shales of the Calico district and elsewhere. APPENDIX Logs of Test Holes on Bristol Dry Lake Drilling- to investigate possible salt resources in cer- tain parcels of land on or near Bristol Dry Lake was carried on during June and July in 1939 bv the Metro- politan Water District of Southern California. The salt is needed for use in connection with a water-softening process for the treatment of water from the Colorado Kiver. For the present the needed supply of salt is beino- purchased from the California Salt Company on Bristol L»ry Lake. The material thus supplied is about 98 percent pure sodium chloride. A series of 19 holes was drilled at this time Borim- was done with a cesspool digger, which cut holes 16 inches ni diameter. The tests ranged in depth from 45 to 152 feet 1 he locations of these test holes are shown on plate 1 The logs, furnished by courtesy of the Metropolitan Water Oistnet, are quoted, with some slight rearrangement of Saline Deposits of Bristol Dry Lake LOG OF TEST HOLE NO. 1 Sec. 25, T. 5N., E. 11 E., 200 feet NNW. of SE corner of section 11 Depth Thickness Description of Materials Encountered (in (in feet) feet) - 5 5 Clay, dark brown 5 - 9 k Sand, fine; and light brown clay 9 -18 9 Clay, dark green, containing gypsum crystals 18 -2k 6 Sand, fine, gypsiferous 2k -Z\\ 3 f p— ^2 Clay, light brown, slightly sandy 27:1-30 Clay, light green 30 -32 2 Clay, light brown, sandy 32 -35 3 Clay, light green 35 -35i 35^-36} 36{-^0 1 2 Clay, dark brown, sandy 1 3 ? Rock salt, hard ko -k6± Clay, dark green, including NaCl crystals up to 1^- inches, and a few CaClo crystals scattered throughout the bed k6 J- 50 3i Clay, sandy, light brown, with a few small salt (NaCl) crystals included An appreciable amount of water entered the hole during drilling. The level remained at 2.8 feet below the surface throughout the drilling. Salometer indicated lk percent salts by weight. LOG OF TEST HOLE NO. 2 Sec. 25, T. 5 N., R. 11 E., 175 feet N. of S. -^ corner of section Depth Thickness Description of Materials Encountered (in (in feet feet) - 6 6 Clay, sandy, brown 6 -10 k Gypsum, with thin beds of sandy clay 10 -is 5 Clay, brown 15 -2k 9 Sand , fine 2k -32 8 Clay, dark brown 32 -36 k Clay, sandy, light brown 36 -38 2 Clay, green 38 -kk 6 Clay, sandy, dark brown kk -50 6 Clay, green Water entered the hole freely during drilling, standing at a ground-water level of 5 feet below the surface of the ground. By salometer test this water contained 4.5 percent salts by weight. ]2 Special Report 13 Depth (in feet) - 5 5 - 7 7 - 9i 9i-13 13 -14 14 -16 16 -19 19 -23 23 -35 35 -41 41 -43 43 -50 LOG OF TEST HOLE NO. 3 Sec. 9, T. 4 N., R. 12 E., about 200 feet SE. of NW. corner of section Thickness (in feet) 5 2 2-1 ? 34 1 2 3 4 12 6 2 7 Description of Materials Encountered Clay, sandy, brown Clay, green Rock salt (halite) Clay, sandy, brown, with few scattered crystals of halite Salt (halite) Clay, sandy, brown Clay, green Rock salt (halite) Clay, green, with occasional 1- to 2- inch streak of salt, and salt crystals disseminated throughout Clay, sandy, brown Rock salt (halite) Clay, green, few scattered salt crystals Relatively little water entered this hole during the drilling, but the hole filled in a 12-hour period following completion of drilling, the water level stand- ing 4 feet below the surface of the ground. By salometer test this water contained 26.4 percent salts by weight, which is a nearly saturated solution mainly of sodium chloride and calcium chloride. Saline Deposits of Bristol Dry Lake 13 LOG OF TEST HOLE NO. k Sec. 9, T. k N., R. 12 E., about lj-00 feet S. of N.^ corner Depth Thickness Description of Materials Encountered (in (in feet) feet) - 5 5 Clay, sandy, brown 5 - 8 3 Clay, green, with a few halite crystals 8 -10 2 Rock salt (halite) 10 -18 8 Clay, green, with a few halite crystals 18 -20 2 Rock salt (halite) 20 -23 3 Clay, green, full of large halite crystals 23 -26 3 Rock salt (halite) 26 -36 10 Clay, green, a few 2- and 3-inch streaks of salt and scat- tered crystals (halite) 36 -*3 7 Clay, brown, slightly sandy ^3 -h5 2 Clay, green, with small halite crystals 45 -^ 3 Rock salt (halite) hS -53 5 Clay, green, a few thin streaks of salt (halite) 53 -5^ 1 Rock salt (halite) 5^ -63 9 Clay, sandy, brown; a few salt crystals throughout 63 -69J 2} Clay, green, scattered salt (halite) crystals 69^-72 Rock salt (halite) 72 -75 3 Clay, green, a few scattered salt crystals 75 -76 1 Gypsum and brown clay 76 -Qh 8 Clay, brown, a few scattered salt crystals Qk -97 13 Clay, green and brown alternating, a few scattered of salt (halite) crystals Ground water (a saturated brine) stands 2.\ feet below the surface of the ground, 14 Special Report 13 Depth (in feet) - 6 6 - 8 8 -10 Thickness (in feet) 10 -13 13 -19 19 -20 20 -27 27 -kO 3 6 1 7 13 ko -53 13 LOG OF TEST HOLE NO. 5 Sec. 9, T. 4 N., R. 12 E., about 800 feet NNW. of E.-jjr corner Description of Materials Encountered Clay, brown Clay, green Clay, brown, scattered crystals of gypsum Clay, green, gypsiferous, iron-stained streaks Clay, green Rock salt (halite) Clay, brown, a few scattered crystals of salt Clay, green, a few scattered crystals of salt up to 2- inch in length Clay, brown in ho?e°^ d p d Zt b r/ leldS / ery llttle VatSr dUrlng dril li*g. Ground water rises in hole to 2 feet below surface and is a saturated brine, tested by salometer. Depth (in feet) -19 19 -20 20 -30 30 -50 50 -5^ LOG OF TEST HOLE NO. 6 Sec. 29, T. 5 N., R. 13 E., about 200 feet NE. of SW. corner of section Thickness (in feet) 19 1 10 20 k Description of Materials Encounterec Clay, brown, occasional thin layers hard lime Lime, hard Silt, grayish brown Clay, dark brown Silt, light gray Ground water was encountered at a rip-nth n-r -sn -r~~+ -, • -^ by weight, determined by salometer ? 3 ***' Salinit ^ was 1-5 Percent Saline Deposits of Bristol Dry Lake LOG OF TEST HOLE NO. 7 Sec. 5, T. k N. , R. 13 E., about 200 feet SE. of NW. corner of section 15 Depth (in feet) Thickness (in feet) Description of Materials Encountered -28 28 -35 35 -66 28 7 31 Clay, Cla j , Clay, brown, numerous crystals of gypsum grayish brown, some gypsum brown, numerous crystals of gypsum Ground water was encountered at a depth of k6 feet; salinity was 25.5 percent by weight, determined by salometer. By analysis sodium chloride 2^.3 percent of brine and calcium chloride k.Q percent by weight. LOG OF TEST HOLE NO. 8 Sec. 5, T. k N., R. 13 E., about 200 feet NE. of SW. corner of section Depth (in feet) Thickness (in feet) Description of Materials Encountered -5^ 5^ -55 55 -90 5^ 1 35 Clay, brown, occasional crystals of gypsum Volcanic ash (glass), light gray Clay, brown, occasional pockets of gypsum crystals Ground water was encountered at a depth of 5k feet; salinity was 28 percent by weight, determined by salometer. Probably some calcium chloride was present. LOG OF TEST HOLE NO. 9 Sec. 17, T. k N. , R. 13 E., about 200 feet SE. of NW. corner of section Depth (in feet) Thickness (in feet) Description of Materials Encountered -38 38 -39 39 -53 38 1 Ik Clay, brown Volcanic ash (glass), light gray Clay, brown, numerous crystals of gypsum Ground water was encountered at a depth of 38 feet; salinity was 26.5 percent by weight, determined by salometer. Brine probably contains some calcium chloride. 16 Special Report 13 Depth (in feet) - 8 8 -13 13 -14 14 -20 20 -54 LOG OF TEST HOLE NO. 10 Sec. 13, T. 4 N., R. 12 E., about 200 feet SW. of ME. corner of section Thickness (in feet) 8 5 1 6 34 Description of Materials Encountered Clay, brown Clay, brown to green Clay, green, numerous crystals of halite Clay, brown to green, occasional crystals of salt (halite) Clay, brown to green, occasional gypsum crystals No water entered this hole. Depth (in feet) - 6 6 - 6£ 6i- 9 9 -10 10 -17 17 -20 20 -46 46 -49 49 -50 LOG OF TEST HOLE NO. 11 Sec. 13, T. 4 N., R. 12 E., about 100 feet SE. of NW. corner of section Thickness (in feet) 6 l 2 2^ ^2 1 7 3 26 3 1 Description of Materials Encountered Clay, brown to green Rock salt (halite) Clay, brown to green; numerous halite crystals Rock salt, hard; used fishtail bit to drill Clay, brown, with gypsum crystals Clay, brown, containing crystals of halite Clay, brown to green, occasional gypsum crystals Volcanic ash (glass), light gray Clay* grayish brown Ground water was encountered at depths of 6 feet and 46 feet percent by weight, determined by salometer. Salinity was 2o . 4 Saline Deposits of Bristol Dry Lake 17 LOG OF TEST HOLE NO. 12 Sec. 36, T. 5 N. , R. 12 E., about 200 feet SE. of NW. corner of section Depth (in feet) - 18 18 - 20 20 - 35 35 - 37 37 - 38 38 - 38^ 38J- h2 k2 -. lj-2§ \2\- k6 46 - 51| 5lJ- 58 58 - 65 65 - 73 73 - 7^ 74 - 75 75i- 77 77 - 84 84 - 87^ 87i- 9^ 94 -102 102 -106 106 -107 107 -108 108 -112 112 -121 121 -127 127 -i4o 140 -142 142 -152 Thickness (in feet) 18 2 15 2 1 31 si 6J ii 7 3i si Description of Materials Encountered 8 4 1 1 4 9 6 13 2 10 Clay, brown Clay, green Clay, brown Clay, green, crystals of halite in lower half Rock salt , hard (had to use rock bit) Clay, green Rock salt, about 60 percent and green clay about 40 per- cent Mostly salt with some clay Rock salt, hard (had to use rock bit to cut) Clay, greenish gray, occasional crystals of halite and gypsum Clay, greenish gray, numerous crystals of halite at top, occasional crystals of halite and gypsum through middle, none noted at bottom Rock salt , hard, had to use rock bit to drill Clay, greenish gray, and brown to green with halite crys- tals at intervals Clay, green (60 percent), and rock salt about 40 percent Clay, light green, with a few halite crystals and thin beds of volcanic ash Rock salt 70 percent and green clay about 30 percent Rock salt, hard, had to use rock bit to cut Clay, green, and halite, latter about 30 percent in lower 2\ feet of this section Clay, brown, occasional large crystals of halite Clay, brown Clay, green Clay, green, with streaks of volcanic ash Clay, dark grey Clay, green Rock salt , hard, had to use rock bit to cut Clay, brown, numerous crystals of halite and gypsum Clay, brown Clay, brown, numerous crystals of gypsum Clay, brown, with a few small crystals of halite A small seepage of water was encountered at a depth of 121 feet; it filled about 1 foot of hole per hour. Clay was moist throughout, and sticky, causing trouble in emptying drilling bucket. Rock salt was hard and difficult to cut, a considerable amount of water being added to facilitate drilling. Five beds of rock salt were penetrated in this hole, aggregating 28 feet of salt drilled besides several zones that carried a considerable proportion of salt. 18 Special Report 13 Thickness (in feet) LOG OF TEST HOLE NO. 13 Sec. 36, T. 5N., R. 11 E.. 150 feet WNW. of £.£■ corner of section Description of Materials Encountered Clay, brown Clay, green Clay, brown, with a few halite crystals Sand, fine, with some water Clay, green Clay, sandy, with some water Rock%fi? y ?h«rr? U \ h f ite CryStalS (about 30 Percent) * 0Ck salt (^lite), had to use rock bit to cut Clay, gray, with a few halite crystals Clay, green, with a few halite crystals Rock salt, hard, had to use rock bit to cut Clay, gray, with streaks of fine sand Sand, grayish brown, fine grained Kock_salt, hard, had to use rock bit to cut ^ItTTr/sllIs** '^ ^ greSn bSlW ' C ° ntai ^ s ^tered From ^T^st^^ the surface in the hole show 252,053 parts per million^ percen^Le bv . h C ° mb * nations ™re calculated to sodium chloride an/7.7 Perceni ?Sc££ cMorid"" ° f *** **" ^ S 25 ' 3 P~«* Depth (in feet) -10 10 -13 13 -18J- 18J-22 22 -23 23 -2k 2k -26 26 -31 31 -32 32 -34 3k -kk LOG OF TEST HOLE NO. Ik Sec. 36, T. 5 N., R. 11 e about 200 feet iw nfqi? n „ !' eei iW ' ot SE - corner of section Thickness (in feet) 10 3 3} 1 1 2 5 1 2 10 Description of Materials Encountered Sand, brown, with streaks of clay Clay, dark gray Clay, brown, with some sand Clay, green Sand, light brown Clay, dark gray Clay, green £2£k_salt, hard, had to use rock bit to drill Clay, green ■" Sand, grayish brown Clay, brown, with a few halite crystals Water stands at a denth nf 1.0 -p Q ~+ • "eight, determined by salometel ^ h ° le ' Sallnity ls 2 ?- 2 P^ent by Saline Deposits of Bristol Dry Lake V.) LOG OF TEST HOLE NO. 15 Sec. 36, T. 5 N., R. 11 E., about 150 feet NE. of center of section Depth Thickness Description of Materials Encountered (in (in feet) feet) 0-2 2 - 4 2 \l ± 2 2 Clay, Sand, brown brown k£- 6 6 - 8 Clay, Sand, brown with water 8 -11 11 -15 3 Clay, Sand, gray, sandy, with a few crystals of gypsum light brown 15 -17 2 Clay, brown, numerous crystals of gypsum and a few of halite crystals 17 -20 20 -22 3 2 Clay, Sand, brown light brown 22 -27 27 -28 5 1 Clay, Sand, brown brown 28 -31 31 -3k 3k -37 37 -^3 ^3 -k5 3 3 3 6 2 Clay, Clay, Clay, Clay, Sand, green gray, sandy green brown clayey, light green Water stands in this hole 5 feet below the surface; salinity is 10. 5 percent by weight determined by salometer. LOG OF TEST HOLE NO. l6 Sec. 16, T. 5 N., R. 12 E., about 200 feet NE. of SW. corner of section Depth Thickness Description of Materials Encountered (in (in feet) feet) 0-2 2 Clay, sandy, grayish brown 2 - 6 k Gypsum, small crystals, and some silt 6 - 9 3 Clay, light brown 9 -10 1 Clay, green 10 -16 6 Clay, brown 16 -19 3 Clay, dark gray, with a few crystals of gypsum 19 -22 3 Sand, clayey, green, a few crystals of gypsum 22 -23 1 Clay, green 23 -26 3 Silt, dark green 26 -31 5 Clay, brown, a few crystals of gypsum in lower part 31 -39 8 Clay, green, with a few large crystals of gypsum 39 -^3 4 Silt, gray ^3 -k$ 2 Clay, brown k5 -k6 1 Gypsum in small crystals and some clay H6 -I4-7 1 Clay, gray, with a few calcium chloride crystals kf -k9 2 Silt, gray k9 -50 1 Clay, green No water was encountered in this hole. 20 Special Report 13 LOG OF TEST HOLE NO. 17 Sec. 16, T. 5 N., R. 12 E. , about 14-00 feet NNW. of SE. corner of section Depth (in feet) - 8 8 -12 12 -17 17 -21 21 -2k 2k -26 26 -28 28 -30 30 -33 33 -3*+ 3k -36 36 -39 39 -to kO -k2 k2 -43 43 -kS kS -50 Thickness (in feet) 8 k 5 k 3 2 2 2 3 1 2 3 1 2 1 5 2 Description of Materials Encountered Clay, brown Clay, green Clay^ brown Clay, green Clay, green, with a few halite crystals Clay, dark gray Clay, brown Clay, brown, with a few large crystals of halite Clay, brown Clay, brown, with a few large crystals of halite Clay, green, with a few large crystals of halite g° ck salt °° Percent) and green clay (kO percent) Rock salt (80 percent) and clay (20 percent) Rock salt , hard, had to use rock bit to cut Clay, green, with a few halite crystals Clay, brown Clay, green, with a few large crystals of halite No water was encountered in this hole. LOG OF TEST HOLE NO. 18 Sec. 26, T. 5 N., R. 12 E., about 300 feet SE. of NW. corner of section Depth (in feet) - 5 5 - 7 7 -10 10 -13 !3 -13i 13|-17 17 -18 18 -19 19 -19J 19J-21 21 -23 23 -25 25 -25j 25i-29 29 -3^ 3k -38 38 -k3 *+3 -43j ^-k7 k7 -50 Thickness (in feet) 5 2 3 3 4 1 1 1 if 2 2 4 5 k 3i 3 Description of Materials Encountered Clay, Clay, Clay, Clay, Rock salt , had Clay, Clay, Clay, Rock Rock Clay, Clay, Rock brown dark gray brown green, with a few crystals of halite to use rock bit to cut green brown green salt, had to use rock bit to cut Rock Rock Clay, Clay, Rock Clay, Clay, salt 50 percent and green clay 50 percent brown, with a few halite crystals green salt , had to use rock bit to cut salt 60 percent and green clay kO percent salt, had to use rock bit to cut green dark gray salt, had to use rock bit to cut brown green Slight seepage of water was encountered at a depth of 3 k feet. Saline Deposits of Bristol Dry Lake 21 LOG OF TEST HOLE NO. 19 Sec. 26, T. 5 N. , R. 12 E., about 500 feet NW. of SE. corner of section Depth (in feet) Thickness (in feet) Description of Materials Encountered - 8 8 -11 11 -18 18 -19| 19J-20 20 -27 27 -28 28 -34 3^ -36J 36^-37 37 -^0| i4-0|- 50 50 -52 8 3 7 7 1 6 2- 1 3* 9i 2 Clay, brown, with a few halite crystals Clay, greenish gray, with a few large crystals of halite Clay, brown, with a few large halite crystals Clay, greenish gray Salt (halite) , drilled with bucket Clay, brown, with a number of halite crystals Clay, green Clay, brown, with a few halite crystals Clay, green, with a few halite crystals Rock salt, drilled with bucket Rock salt 60 percent and green clay ^+0 percent Rock salt, had to use rock bit to drill Clay, green, with a few halite crystals A small seepage of water was encountered at a depth of 37 feet in this hole, 4910 5-51 2M printed in California state printing office