EMBANKMENTS AT BUFFALO SPRINGS. 115 



The sea-cliflP marking the horizon of the highest water-line is a conspic- 

 uous feature on the more exposed shores in the area embraced by the 

 accompanying map, but cannot be distinguished on tlie alluvial slopes of 

 the bays, where the water was shallow and sheltered from waves and cur- 

 rents. The material cut away to form the sea-clifiFs shown in the lower 

 part of Plate XIX was carried southward and built into a series of looped 

 and V-shaped bars, inclosing deep cups, at another angle of the shore, a 

 few hundred yai'ds away. 



EMBANKMENTS AT BUFFALO SPRINGS, NEVADA. 



Passing north from Carson Desert, one crosses a low, narrow divide, 

 once a strait in Lake Lahontan, and enters a valley having a broad playa 

 in its central portion and surrounded on all sides by alluvial slopes, above 

 which rise angular mountain crests. Around the borders of the valley, at 

 an elevation of about 300 feet above the playa, the Lahontan beach can be 

 traced with distinctness. The lowest point on the pass at the north end of 

 the valley is higher than the Lahontan beach, and was never crossed by the 

 waters of the old lake. The valley was therefore a typical cul-de-sac at the 

 time it was flooded by .Lake Lahontan. Owing to the abundance of loose 

 material furnished by the alluvial slopes, the shore phenomena in the valley 

 consist almost entirely of works of construction. The most common of the 

 structures due to shore action are rounded beaches of gravel, looped bars, 

 and peculiar embankments, not designated by a special name, that extend 

 out nearly at right angles to the general trend of the ancient shore and form 

 conspicuous features in the topography of the basin. A locality near Buf- 

 falo Springs, at which these various features are well displayed, is repre- 

 sented on Plate XX. On the map the crests of the bars are liglit and the 

 slope of their sides represented by hachures. The figures at various 

 points represent vertical distances in feet below the Lahontan beach, 

 which is taken as zero. They may be considered as soundings made in the 

 ancient lake during its highest stage. Each of the bars has the form of a 

 railroad embankment, with a somewhat rounded crest; they are even more 

 clearly defined when examined in the field than they appear on the map, as 



