Lake Otero, N. Mex.—Hcrrick. 187 
furnishes commercial supplies. Analyses of the "white sands" 
show that this gypsum sand contains very little salt. 
From what has been said it will appear that along tlit 
entire western border of the old lake the later formation has 
been removed, perhaps by combined wind and water action, 
leaving the Otero saliferous formation exposed over several 
townships, the material therefrom havingbeen driven eastward 
by the prevailing winds. The, castcn margin is suiifering 
destruction in another way. Streams from the Sacramento 
mountains attack the sandy upper layer's (Tularosa forma- 
tion) and by driving their waters against the advancing dunes, 
forming deep arroyos and, preliminary to them, series of sink 
holes in which in some cases water may Ijc heard running. 
The arroyos are extended and new ones are formed by the 
confluence of these sink holes. During wet times the roof of 
such caverns may cave in and we \\2i\<^. found the bodies of 
cattle, head downward, in such falls. It is apparent that so- 
lution rather than erosion is the great agent of destruction 
here. The arroyos so fomied may end abruptly against the 
central dune area or may form salt flats along its eastern 
margin. These arroyos are covered with salt grass and salt 
bush and have the usual saline efflorescence. 
Much of the drainage from the east is not by way of open 
arroyos but reaches and even penetrat.'^s the Otero formation 
and passes through underground channels. Frequently these 
underground waters meet obstacles, or perhaps create them 
by depositing lime and g}-psum, and so are forced to find 
an escape at the surface. These springs have a considerable 
artesian head, building up cones to the hight of twenty-five 
feet or more. Attempts have been made to utilize these arte- 
sian waters for irrigation but in all cases so far as followed 
up the results have been disappointing because of the saline 
impurities in these waters. Excavat'on has in some cases 
opened large subterranean chambers in the vicinity of such 
springs and the soil is marly and inapt for cultivation. 
The Tularosa Formation has been incidentally described. 
It consists of sandy marl largely gypslferous and moderately 
saline. It is usually covered with scanty desert vegetation 
and is rolling from the dune formation usually accompanying 
it. The presence over its entire extent of recent fresh-water 
