Dawson County.-A sample of brine from the Burns well No. 1 (No. 5 on map), in Dawson County, was found to be fairly concentrated, containing 0.2684 gram per cubic centimeter of soluble salts, in which K2O amounted to 1.91 per cent. A sample of polyhalite taken from this well (lump of about 5 grams) was found upon analysis to contain 15.2 per cent of K,O, equivalent to 23.2 per cent in the soluble salts. This is the highest-grade Texas sample yet analyzed at the Geological Survey. As the theoretical potash (K2O) content of polyhalite is 15.6 per cent, it is evident that the material from which this sample was taken is practically pure polyhalite. It is also plainly of commercial grade, as it compares very favorably in potash content with the raw salts mined in Germany, which generally range from about 9 to 16 per cent K2O, as well as with the general run of raw salts mined in Alsace, which average not over 18 per cent K2O. In this connection it may be noted that a selected sample of cuttings from the G. A. Jones well, in Borden County (see table and map), ran 22.9 per cent of K,O in the soluble salts.

Ector County-The Newnham well No. 1-A, near Odessa, Ector County (No. 12 on map), drilled by the Farmers Oil Co., of Lancaster, Pa., has been visited from time to time by the Survey representative. At last accounts drilling with standard tools was stopped above the salt beds at a depth of about 970 feet, pending the settlement of financial difficulties of the company in its home State. Since the death of H. O. Hartzell, president of the company, which occurred early in 1924, reorganization has been in progress. It is expected that work may be resumed with a core-drilling machine during the current year.

Howard County. Samples have been analyzed at the Geological Survey from three lakes in Howard County, located as follows: No. 1, secs. 13 and 14, T. 1 S., block 35; No. 2, sec. 12, T. 1 S., block 35; No. 3, secs. 13 and 14, T. 1 S., block 35. A sample of salts_taken from the south side of the Texas & Pacific Railway in sec. 13, T. 1 S., block 35, was also analyzed. This salt sample contained merely a trace of potash. The brines from lakes Nos. 1 and 2 were very dilute and their potash content insignificant. Brine from lake No. 3 was considerably more concentrated and contained appreciable amounts of potash, though probably not enough to have commercial impor

tance.

Hudspeth County. Samples of salt submitted to the Geological Survey from a salt lake on survey No. 335, in Hudspeth County, were found to contain only traces of potash. The salts consisted chiefly of sodium chloride with some sodium sulphate.

Kent County.-Earthy material from a locality near Girard, in Kent County, yielded upon analysis only a trace of potash.

Midland County.-Samples of salt and of brine from the salt lake in sec. 12, block 38, about 13 miles south of Midland, Midland County, yielded on analysis only insignificant amounts of potash, although the brine was strongly concentrated. A sample of brine from Peck's Lake, in sec. 31, block 37, in the same county, which was considerably more dilute, yielded similar results.

Mitchell County.-Samples have been analyzed in considerable number from 10 wells in Mitchell County, located as follows:

Practically all the samples analyzed from these wells show small amounts of potash, but except in the sample taken from a depth of 917 to 923 feet in the Miller well No. 2 these amounts are insignificant. Even the sample cited is low in potash as compared with those listed in the preceding table.

Two of

Reagan County.-Interest has centered on the wells in Reagan County during 1923 for two reasons. The potash discovery in the Santa Rita No. 1 well (No. 11 on map) of the Texon Oil & Land Co., which has been announced in previous statements of the Geological Survey, extended the area of known potash occurrence nearly 50 miles southeastward. Then the discovery of oil in this same well at a depth of 3,055 feet caused considerable local excitement and led to the drilling of other wells in the same general region. these, Santa Rita Nos. 2 and 3, drilled within 800 feet of each other and of Santa Rita No. 1, have been discussed in Press Notice 16953, issued by the Geological Survey. Their potash records are shown graphically in Plate II. They represent the first instance of wells drilled near together in Texas disclosing significant amounts of potash. Although the information that they furnish is purely qualitative, they suggest strongly that a fairly continuous bed of potash of commercial quality may be present there at a depth not greater than 1,500 feet. They are of further interest in that they also found oil. These three wells are now controlled by the Big Lake Oil Co., a concern formed by the Texon Oil & Land Co. in conjunction with the Transcontinental Oil Co. A railroad station and settlement named Texon has been established on the Kansas City, Mexico & Orient Railroad near these wells.

Santa Rita well No. 4, which is in sec. 35, block 1, south of the railroad, has furnished some 29 samples that have been analyzed for potash at the Geological Survey. Those taken between depths of

1,210 to 1,552 feet show significant amounts of potash as follows, though none of them may be considered rich.

Potash-bearing samples from Santa Rita well No. 4, Reagan County, Tex.

Santa Rita well No. 5, in the same general region but in sec. 13, block 2, north of the railroad, has furnished 24 samples that have been analyzed by the Geological Survey. Of these, 17, ranging in depth from 1,150 to 1,500 feet, were found to contain significant though relatively small amounts of potash-that is, 1 per cent or more of K2O in the sample. The richest sample came from a depth of 1,370 to 1,380 feet and contained 3.36 per cent of K,O, equivalent to 3.58 per cent in the soluble salts.

The Santa Rita well No. 8, in sec. 3, block 2, near No. 5, has furnished 37 samples that have been analyzed for potash. Of these, 17 have shown more than 1.5 per cent of potash, as listed in the following table:

Potash-bearing samples from Santa Rita well No. 8, Reagan County, Tex.

The Geological Survey has also analyzed 11 samples from Santa Rita well No. 7, altitude 2,837 feet, in sec. 27, block 1, southeast of

No. 8. These came from depths of 1,252 to 1,380 feet. All showed traces of potash but none as much as 1 per cent in the sample. The Santa Rita well No. 9, altitude 2,722 feet, 1,000 feet east of No. 1, is reported as a 1,000-barrel oil well, but the details regarding the potash found in it are not now available for publication.

Reagan County has thus far furnished more definite evidence of the presence of potash than any other county in southwestern Texas and may therefore be regarded as a favorable region for core-drilling tests, but it is probable that other counties to the west and northwest may yield equally good or better evidence upon further exploration. Scurry County.-The Moore well No. 1, 111⁄2 miles south of Ira, in Scurry County, has furnished 75 samples that have been analyzed at the Geological Survey. All of these show some potash, but in none is there more than an insignificant amount. The best sample, taken from a depth of 930 to 940 feet, yielded 0.71 per cent of K,0, equivalent to 1.19 per cent in the soluble salts. There were several samples, however, that contained potash of better quality than the sample just cited but in smaller proportion. The best of these contained only 0.36 per cent of potash, but this represented 6.92 per cent of the soluble salts. It came from a depth of 650 to 670 feet.

Terrell County.-Some 37 samples from the Folsom well No. 1, in sec. 148, block D-7, 10 miles south of Watkins, in Terrell County, have been analyzed by the Geological Survey. None of these showed more than traces of potash.

INTERPRETATION OF RESULTS

The unsatisfactory nature of samples taken with churn-drill or rotary outfits, such as were used in the wells mentioned above, especially if the interval between the samples is greater than 5 feet, is readily apparent. The mixing of the material effectually prevents the recognition of individual beds unless they are very thick. The dangers of "salting" lower beds by material from higher levels and of misinterpretation caused by "hangover bailings" are ever present. The necessary water in the hole, by its solvent effect on salts of differing solubilities, may either enrich or impoverish the sample, and this effect is intensified if the water is in contact with the sample for any great length of time. The results indicated in Plate II are therefore to be regarded as suggestive rather than as giving any accurate idea of the number, character, and quality of the individual

beds.

3

The analyses recorded in Plate II have been made on the arbitrary laboratory basis of 1 gram of sample to 100 cubic centimeters of water. Commercial practice may find some other proportion more suitable. According to Steiger, 1 gram of polyhalite contains 0.452 gram of CaSO,, 0.199 gram of MgSO,, 0.289 gram of K,SO,, and 0.060 gram of water. Although the presence of other salts will slightly change the figures, 100 cubic centimeters of pure water at 25° C. will dissolve 0.208 gram of CaSO,. This dissolved CaSO,, added to the easily soluble MgSO, and K,SO, in 1 gram of the mineral, will make 0.696 gram, or 69.6 per cent of the soluble salts. By calculation we find that the 15.6 per cent of K,O in pure polyhalite becomes 22.4 per

1922.

Steiger, George, Potash salts of western Texas: Chem. and Met. Eng., vol. 26, pp. 175-176, Jan. 25,

cent of K,O in the soluble salts. If a larger or smaller amount of water is used this figure will vary accordingly. The 22.9 per cent of K2O at the Jones well and the 21.10 and 23.20 per cent of K2O at the Burns well (p. 179) probably indicate the presence of pure polyhalite. There seems to be no good reason why the occurrence of potash in Texas should be limited to the mineralogic combination found in polyhalite, though both chemical and optical examinations have thus far failed to identify other salts. Additional types corresponding with the more common German salts are to be confidently expected.

NEED FOR FURTHER EXPLORATION

Core drilling is needed to give accurate information. Drillers are urged to consider potash as well as oil in sinking new holes and to provide for coring the salt beds. Two attempts of this sort already made have been abandoned, at least temporarily, before the salt beds were reached. These failures were due in part to the lack of recognition by the drillers of the necessity of keeping the well properly cased.

A drilling solution other than water will be needed for the coring of the salts; otherwise the core may be damaged or lost. The Germans have used a 30 to 35 per cent solution of magnesium chloride for this purpose with apparently satisfactory results. Magnesium chloride, however, would be expensive in western Texas, and it is probable that a saturated brine such as may be obtained from some of the lakes in the region may serve the purpose.

The negative result at the Geological Survey's boring at Cliffside, which was thought to be favorably located, shows that barren areas may be interspersed with possibly productive areas. The only way in which the productive areas can be delimited is by drilling, and it may be necessary to drill many holes before the essential facts can be gathered. Gale notes that when systematic exploration for potash began in Alsace more than 100 deep borings were put down, 95 of which penetrated rock salt. Of these only 17 found potash layers. If this experience is any criterion for Texas it will be a long time before much will be known of the commercial value of the potash beds there from wildcat operations. Some far-sighted company with a view to future rather than immediate returns, or even the Government itself, should undertake a systematic campaign of investigation. It is believed that the evidence already obtained points strongly to the probability of deposits of commercial value and would justify the needed expenditure.

REVIEW OF AMERICAN POTASH SITUATION

POTASH RESOURCES OF THE UNITED STATES

In 1910 the German Government passed a law virtually creating a Government potash monopoly with absolute control over both production and prices. This act was accompanied by a sharp advance in price to American consumers, despite contracts then existing and antedating this act. This situation led to determined efforts on the part of the United States Government to find cheap

Gale, H. S., The potash deposits of Alsace: U. S. Geol. Survey Bull. 715, pp. 17-55, 1920.