THE DIVINE ABYSS 



The next step, or platform, the Cretaceous, slopes 

 down gradually or dies out on the step beneath it;, 

 then comes the Jurassic, which ends in white sand- 

 stone cliffs several hundred feet high; then the 

 Triassic, which ends in the famous vermilion cliffs 

 thousands of feet high, most striking in color and in 

 form; then the Permian tread, which also ends 

 in striking cliffs, with their own style of color and 

 architecture; and, lastly, the great Carboniferous 

 platform in which the canon itself is carved. Now, 

 all these various strata above the 'canon, making 

 at one time a thickness of over a mile, were worn 

 away in Pliocene times, before the cutting of the 

 Grand Canon began. Had they remained, and been 

 cut through, we should have had a chasm two miles 

 deep instead of one mile. 



The cutting power of a large, rapid volume of 

 water, like the Colorado, charged with sand and 

 gravel, is very great. According to Major Button, 

 in the hydraulic mines of California, the escaping 

 water has been known to cut a chasm from twelve 

 to twenty feet deep in hard basaltic rock, in a single 

 year. This is, of course, exceptional, but there have, 

 no doubt, been times when the Colorado cut down- 

 ward very rapidly. The enormous weathering of its 

 side walls is to me the more wonderful, probably 

 because the forces that have achieved this task are 

 silent and invisible, and, so far as our experience 

 goes, so infinitely slow in their action. 



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