WASTE-FILLED BASINS 587 



the streams, and then redeposited by evaporation. (Hill and 

 Vaughan-30 '.236. ) 



Basins Filled by Rivcr-]V ashed Waste. There are many ex- 

 amples of great basins surrounded by mountains and filled to a 

 certain extent by the waste washed from the mountains. The 

 larger of these basins are generally formed by tectonic movements, 

 the process being a downwarping. An example of such a valley 

 holding a "waste lake" is the upper Arkansas valley, back of the 

 Front Range of the Rocky Mountains. As the basin was forming 

 by warping, the rivers deposited their load on its floor, while at the 

 same time the outlet of the Royal Gorge was being cut through the 

 Front Range. The plains of waste within the basin slope forward 

 from the mountainsides, but they have been only slightly dissected 

 so far. Another excellent example is found in the \^ale of Kash- 

 mir, enclosed by the front and middle ranges of the Himalayas in 

 northwest India. In area this vale equals that of the Connecticut, 

 being elliptical in form, a hundred miles long from southeast to 

 northwest, and forty or fifty miles broad. It is formed by a down- 

 warping between two lofty mountain ranges, which, for the most 

 part, have very steep sides. The floor of the valley is deeply 

 filled with river-laid waste, coarse near the mountains, but free 

 from pebbles at the center. Its depth is measured probably by thou- 

 sands of feet, while its surface elevation is more than 5,000 feet 

 above sea-level. Across this plain meanders the Jhelam River, 

 which escapes by a deep gorge through the enclosing mountains. 

 Southern Europe furnishes another good example of a waste- 

 floored basin in the oval plain of Hungary, which has a diameter of • 

 about 200 miles. Gravelly, sandy and loamy materials brought by 

 the rivers from the enclosing mountains have formed this plain, 

 which rises slightly toward the mountains, where it is formed of' 

 gravels, while the level center is a fine silt plain, resembling an 

 abandoned lake bottom. The Danube and its tributaries meander 

 through it and escape by the deep gorge of the Iron Gate cut 

 through the Transylvanian Alps. 



A somewhat similar basin lies in southwestern Wyoming, 

 within the embrace of a series of mountain ranges, the Wasatch on 

 the west, the LTinta on the south, and the Wind River Ranges on 

 the north and east. The Green River flows through this basin and 

 escapes by a deep canyon through the Uinta Mountains. The 

 original deep filling of waste material has now been extensively 

 trenched by the rivers and converted into a dissected upland, with 

 valleys cut into the old waste deposit, in some cases a thousand feet 



