PHYSICAL FEATURES OF COLORADO VALLEY. 391 



ent level of the river. Now that bed is gone from the mountains, yet 

 it can be seen turned up on edge against the flanks of the mountains, 

 dipping under the beds of rocks found still farther out from the range. 

 Follow it down, and doubtless we could trace it to a depth much 

 below the level of the sea. While the folds were forming, the up- 

 turned flexures were cut down, and the troughs in the down-tnrned 

 flexures were filled up, and we have more than 8,000 feet of these 

 later sediments to the north of the Uinta Mountains. 







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Fig. 3. Diaclinal Valley. 



It will thus be seen that the upheaval was not marked by a great 

 convulsion, for the lifting of the rocks was so slow that the rains 

 removed the sandstones almost as fast as they came up. The moun- 

 tains were not thrust up as peaks, but a great block was slowly lifted, 

 and from this the mountains were carved by the clouds patient 

 artists, who take what time may be necessary for their work. 



We speak of mountains forming clouds about their tops : the 

 clouds have formed the mountains. Lilt a district of granite, or 

 marble, into their region, and they gather about it, and hurl their 

 storms against it, beating the rocks into sands, and then they carry 

 them out into the sea, carving out caiions, gulches, and valleys, and 

 leaving plateaus and mountains embossed on the surface. 



Instead of having a rounded billow, we have an irregular table, 

 with beds dipping to the north, on the north side of the axis, and to 

 the south, on the south side, and in passing over the truncated fold 

 we pass over their upturned edges. 



