POTASH SALTS AND OTHER SALINES IN THE GREAT BASIN REGION. 53 



Dolbear ^ presents the followiBg estimate of quantities for the 47-foot bed of brine 

 and crystallized salts: 



In brine: Tons. 



Potassium chloride 6, 455, 600 



Anhydrous borax 1, 900, 000 



Sodium carbonate 6, 630, 000 



In saline material: 



Potassium chloride 23, 900, 000 



Anhydrous borax 15, 200, 000 



Sodium carbonate 108, 500, 000 



Sodium bicarbonate 42, 700, 000 



Weight of brine 144, 000, 000 



Weight of salts 656, 000, 000 



The figures given are conservative. Dolbear states that the brine contains 4.49 

 per cent of potassium chloride. The result upon the Bureau of Soils samples is less 

 than this, 3.51 per cent being obtained by their analyses. 



Comparison of saline residues. 

 [Per cent of anliydrous residue.] 





Ca. 



Mg. 



Na. 



K. 



CI. 



Br. 



I. 



SO4. 



CO,. 



PO4. 



AsOi. 



B4O7. 



Searles 



Death Valley 



Silver Peak 



0.0 

 .002 

 1.05 



.02 

 .04 



.33 



.25 

 .55 

 .90 



Trace. 



0.003 



.64 



.01 

 .10 



2.22 



2.28 



.49 



1.56 



33.57 

 36.12 

 35.14 



38.09 

 37.93 



33.31 



33.84 

 36.68 

 34.83 



6.06 

 2.63 

 2.94 



1.62 

 1.85 



1.92 

 2.11 

 1.94 



37.02 

 53.70 



58.86 



24.82 

 23.34 



55.36 

 41.04 



47.88 

 23.77 



0.094 



0.004 



12.93 

 5.62 

 L26 



9.93 

 12.86 



6.53 

 5.25 

 3.76 

 21.29 



6.70 

 .18 

 .30 



24.55 

 23.42 



.07 

 14.28 

 7.93 

 17.34 



0.30 



0.0S3 



3.00 











Trace. 



Owens 1 2 







.11 



.05 



.14 



Mono 2 







.32 



Great Salt Lake 2. 













Pyramids 



Wjnnftmiipnn.z. , , 



















Walker2 

























1 Owens Lake, nitrate=0.45 per cent. 



2 Clarke, Bui. No. 491, U. S. Geo!. Survey, pp. 144-146. 



Comparison of the saline residues from residual brines, from lake waters in which 

 concentration has proceeded to a considerable extent and from lake waters in which 

 concentration is in initial stages is shown in the accompanying table. Regional dif- 

 ferences are, of course, apparent, and must be considered. With the exception of the 

 calcium and magnesium content, the saline residue of the Death Valley brine closely 

 approximates that from Great Salt Lake. Silver Peak is lower in sulphates but more 

 nearly approximates Death Valley. Mono and Owens Lake closely compare and, 

 save for the higher proportion of carbonate, approximate the Searles brine. The 

 residues of Pyramid and Winnemucca are relatively higher in chlorides and lower in 

 sulphates than Mono and Owens. The residue of Walker Lake is high in sulphates 

 and carbonates and lower in chlorides than Pyramid or Winnemucca. Little concen- 

 tration of potassium is indicated in the last two groups, but decided concentration is 

 shown in the first group, and borates are progressively concentrated from the third 

 to the first group. Nitrate is concentrated from the third to the second group. Great 

 Salt Lake is the only water in the second and third groups in which precipitation of 

 salines is taking place. This residue can be considered intermediate between groups 

 1 and 2. 



COLUMBUS MARSH. 



Columbus Marsh is near Coaldale, Esmeralda County, Nev. The area is 32.5 square 

 miles. It receives the drainage of Fish Lake Valley from the south and the basin 

 immediately surrounding the marsh. Two shore lines are present, one about 60 feet 

 above the flat and the other, reported by E. E. Free, at 104 feet. The lake could not 

 have been of much greater extent than the marsh. The comparative shallowness 

 would indicate a relatively small amount of salines. The present surface is a broad 

 plain roughened by very small, more or less rounded, hummocks. There is very little 

 salt in the form of crusts. The surface is dry enough at most times to support a road 



1 Eng. and Mining Jour, cited before. 



