64 
BULLETIN" 61, U. S. DEPARTMENT OF AGEICULTUEE. 
The shore lines in the bottom of the basin, which appear with great distinctness, indi- 
cate the slow recession and evaporation of the waters. Sufficient time is indicated 
for the development of a structure similar to that shown in sketch b. Wind erosion, 
no doubt, played an important part in the closure of the saline beds. The soft char- 
acter of the Lahontan sediments and the fact that the prevailing winds are from the 
west would indicate favorable conditions for seolian action. The east end of the 
Carson Desert, and particularly that portion along the flanks of the Sweetwater Range, 
is conspicuous for the large sand dunes which have resulted from the wind action of 
the present. 
The general features involved in the search for the buried salines of the Carson Sink 
may well be considered. A study of the probable structural relations attending the 
formation and closure of a saline deposit such as might have taken place in the Carson 
Sink has shown that the most favorable area is removed from the delta area, either old 
or new. In the particular case of the Carson Desert a line might be drawn at the present 
mouth of the Carson and extending southeast and northwest. Southwest of this line 
is the delta area. Northeast is the area considered as most favorable for the search of 
a saline deposit. The area between the line established above and the lowest con- 
tour — 3,900 feet — inclosing the present lake is about 350 square miles. The main 
deposit of Searles Lake occupies an area having a ratio of 1 to 404, as compared with 
the area of the whole present basin including the salt deposit. The drainage area of 
the Carson and Humboldt Rivers is 27,575 square miles. Using the above ratio would 
give a probable area of saline deposit of 68 square miles. The extent of a saline deposit 
would be determined by its thickness. Consequently the above area might be larger 
or smaller. Again, the deposit might be divided, which is not at all unlikely in the 
present case. The prospecting problem would be to locate by boring an area greater 
or less than 68 square miles in an area of 350 square miles. 
The nature of the saline bed^ if it were discovered, might be similar to that in Searles, 
or the salines might be distributed in a relatively thick bed of seolian sediments. 
Respecting the probability of potassium little can be said. Gale's discovery in 
Columbus Marsh opens up possibilities which in my judgment would warrant explora- 
tion in this area. 
The only other instance of exploration for buried salines is in Railroad Valley, Nev., 
where a ] , 200-foot bore was sunk, but without results. The valley is unlike the Carson 
Sink in that no large stream discharges into it, and there is no lake of consequence. 
The results of the bore have been discussed. 
SALINES IN PRESENT LAKES. 
The composition of the waters of the more important lakes of the basin region are 
given in Table XV (Appendix). The three most important lakes from the standpoint 
of concentration and amount of salines are Great Salt, Owens, and Mono Lakes. The 
computed quantities of the more important salines in these lake3 are given in the 
table which follows: 
Quantities of salts in Great Salt, Owens, and Mono Lakes. 
Lake. 
NaCl. 
Na s SO<. 
KC1. 
NasCO,. 
NasB^Or. 
Great Salt l 
Tons. 
400,000,000 
20,000,000 
86,099,600 
Tons. 
30,000,000 
22,000,000 
47,586,400 
Tons. 
Tons. 
Tons. 
2,140,000 
10,538,000 
22,000,000 
92, 101, 100 
Mono 2 
945,100 
1 Monograph 1, U. S. Geol. Survey, p. 253. 
2 8th Annual Report. Quaternary History of Mono Valley, Cal., pp. 295-296. 
been recalculated to potassium chloride in the case of Owens Lake. 
Potassium sulphate has 
Salt is separated from the brines of Great Salt Lake and at Owens Lake sodium 
carbonate and bicarbonate have been separated by solar evaporation and crystalliza- 
tion for a number of years. At Large Soda Lake, Nev., soda was also separated. Out- 
side of this, there has been no other commercial utilization of the waters of the basin 
lakes. Only two other lakes in the basin approach the three mentioned above in 
degree of salinity— South _ and Middle Alkali Lakes, Oreg. (PL V, fig.,1.) The 
saline content of the remaining lakes is of little present importance. No important 
concentration of potassium salts has taken place in the present lakes, excepting incon- 
sequential cases which have been mentioned before. Later investigations have not 
supported the earlier estimates of notable concentrations of potash salts in Abert Lake 
and the Surprise Valley. (PL V, fig. 2, and PL VI.) 
