SODA LAKES, NEAK RAGTOWN, NEVADA. 



On the Carson Desert, about 2 miles noi'theast of Ragtown, are two 

 circular depressions that are partially filled with strongly alkaline waters 

 and known as the Soda Lakes or Ragtown Ponds By reference to the 

 accompanying map (Plate XVI), on which the contour lines are drawn at 

 intervals of 20 feet, it will be seen that the lakes occupy deep depressions 

 in low cones. The larger lake is 268.5 acres in area, and the smaller is a 

 pond of variable size.^^ The form of the larger depression is still farther 

 illustrated by the cross-section given at the bottom of the plate, which has 

 been constructed from actual measurements with an engineei''s level and a 

 sounding line. The rim of the larger lake in its highest part rises 80 feet 

 above the surrounding desert, and is 165 feet higher than the surface of 

 the lake which it incloses. The outer slope of the cone is gentle and merges 

 almost imperceptibly with the desert surface; but the inner slope is abrupt 

 and at times approaches the perpendicular. A series of careful soundings 

 gives 147 feet as the greatest depth of the lake. The total de])th of the 

 depression is- therefore 312 feet, and its' bottom is 232 feet lower than the 

 general surface of the desert near at hand. 



The walls encircling the lake exhibit well exposed section? of stratitied 

 lapilli, mingled with an abundance of angular grains, kernels, and mas.ses 

 of basalt, some of which are 2 and 3 feet in diameter and scoriaceous, 

 especially in the interior. Mingled with this angular and rough material 

 is a great quantity of fine dust-like lapilli, and some rounded and worn 

 pebbles of rhyolite. Interstratified with the lapilli occur marly lake-beds 

 containing fresh- water shells and dendritic tufa, as is indicated in the 

 accompanied generalized section of the crater walls (Plate XVII, Fig. A). 

 Both the lapilli and the lake-beds are evenly stratified, and exhibit diverse 

 dips. On the interior of the larger crater, on the south side, the dip is 

 towards the lake at an angle of about 30°. On the east side the stratifi- 

 cation appears quite horizontal, but may, perhaps, be inclined away from 



^The smaller lake, when the accompanying map was made, hart been so changtcl by excavation 

 and the construction of evaporating vats that its original form had been destroyed. Its surface is 20 

 feet higher than the larger lake, and lio feet below the general desert surface. The highest point on 

 the crater rim is 80 feet above the bottom of the depression. 



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