The Mojave Desert 



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The topography is typical of the western deserts, consisting 

 of bare mountain ranges and isolated knobs separated by nearly 

 flat arid belts of varying width. The mountains rise abruptly 

 from the desert, in places almost precipitously. The appear- 

 ance of the mountains suggests that they are the summits of 

 more massive ranges whose lower slopes are submerged beneath 

 unconsolidated desert deposits. It is thought the irregularly 

 distributed ranges and peaks of the southeastern Mojave Desert 

 are ridges and peaks of a former vast mountain system compar- 

 able to the Sierra Nevada, which has been lowered by subsidence 

 of the region, and by erosion, which has resulted in tremendous 

 valley-filling. Alluvial fans occur at the mouths of gullies, 

 and these unite into broad aprons which slope gently toward 



Photo by Eliot Blackwelder 



FIG. 35. Deeply dissected Afton Basin. An arm of Manix Lake, Mojave 

 Desert, looking north toward Cave Mountain. Black shadows obscure the 

 eroded slopes in foreground. 



the centers of the basins. In the center is generally a flat nearly 

 level area known as a playa, dry lake, or alkali flat. Such flats 

 may be covered with water during parts of the year, and they 

 are commonly covered with a white crust of alkali or salt. 

 Toward the west the surface of the desert is generally level. 

 Toward the east it is marked by isolated knobs and short ranges 



