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GEOLOGY OF THE DENVEK BASIN. 



distance of about 500 feet. In consequence of the near approach of Green 

 Mountain to the line of the great fold, this exposure on its western face 

 exhibits very clearly the extent to which its strata have taken part in that 

 folding - . At the top of the section the heavy conglomerates have a slight 

 eastern dip; at its base a dip of 45° is shown, and at a distance to the 

 westward but little greater than the known thickness of the intervening- 

 strata the beds are found in vertical position. 



In order to determine the total thickness of the Denver beds and the 

 relative positions of prominent horizons, a straight profile line was surveyed 

 across the mountain, passing up the outcrop described, as nearly parallel to 

 the direction of dip as possible. The course of the section is N. 42° 30' E. 

 and the direction of the dip is X. 74° 30' E., hence there is a divergence 

 of 32° between them. By projecting the outcrops of distinct horizons from 

 the section line upon the line of dip, and bv estimated average dips for 

 certain subdivisions of the sections, an approximate determination of the 

 total thickness of the section has been made. 



Estimated thickness of Denver formation. 



Iii regard to the average dips assumed in the above table it should 

 be explained that at various places on the line of the profile the dip can be 

 determined approximately, though seldom very accurately. The strata of 

 the Arapahoe conglomerate horizon are found to lie vertical. Above this 

 to the dark andesitic conglomerate at the base of the section 110 dip can be 



