58 BULLETIN^ 54, U. S, DEPARTMENT OF AGEICULTURE. 



regards them as due to wind erosion. The similar though smaller 

 wind-eroded hollows of the Estancia Basin, New Mexico, were noted 

 on page 49, and the writer has seen analogous depressions in the 

 AlkaH and Warner Basins, Oreg. Both volcanic and eohan basins 

 are likely always to be too small to have importance for the present 

 study. This is certainly true of all known American examples. 



THE POSSIBILITIES OF POTASH. 



In the preceding pages there are named specifically nearly 200 

 inclosed basins. Some of these are so obviously unimportant as to 

 require no further mention. One hundred and twenty-six, which are 

 somewhat more important, are given in Table I, with the area and a 

 brief description of each, the arrangement being the same as that 

 followed in the text. It is certain that any basins of possible value 

 for potash will be included in this list, and it is just as certain that 

 many that are included wiU have no possible value. Many of the 

 latter are easily ehminated. First, it is obvious that no accumulation 

 is to be expected in a basin which has recently overflowed either into 

 the sea or into another basin. Applying this to the hst of Table I, it 

 is possible to ehminate. from further consideration 62 basins, of which 

 16 were once tributary to Lahontan, 9 to' Bonneville, 11 to the 

 Amargosa and the Mojave, 7 to miscellaneous inclosed basins, and 19 

 more or less directly to the sea. These totals include 10 basins the 

 previous drainage of which is not absolutely certain, though ex- 

 tremely probable. These are the Clover Basin, the Goshute-Steptoe 

 VaUey, the Murray Valley, the Ralston Valley, Stonewall Flat, Sum- 

 mer Lake, Long Valley (northwestern Nevada), Duck Flat, the Big 

 Smoky VaUey, and the Smiths Creek Valley. The nature of the 

 doubt in each case can be ascertained by reference to the preceding 

 chapter. 



A second general eUmination can be made on the ground of small 

 area. It is difficult to set exactly the hmiting area which a basin 

 must have in order to be promising, but it seems probable that basins 

 which cover less than 500 square miles may safely be disregarded. 

 Their potash deposits, if existent, would doubtless be small, and de- 

 tailed prospecting would scarcely be warranted at least until larger 

 basins have been explored. Applying this criterion to the remaining 

 basins of Table I, we eliminate 10 more, AlkaU Lake, Garfield, Teels, 

 Huntoon, Goldfield, Sheep Range, Willard, Granite Mountains, Owl, 

 and Encino. It is possible also to ehminate 12 others which were 

 very probably drained, but which, in any event, are smaller than the 

 upper hmit which we have set. These are Warm Springs, Allan 

 Springs, Mesquite (part of the Pahrump), Acme, Luning, Mina, 

 Monte Cristo, Kawich, Yucca, Aurora, Deep Springs, and Pinos WeUs, 

 The conclusioa that these small basins lack practical value does not 



