182 GEOLOGY OF THE DENVER BASIN. 



though the differences axe perhaps not very pronounced to the unaccus- 

 tomed eve. 



Fossil remains. — As far us present experience goes the strata of the plains 

 are richer in animal remains than the better-exposed strata of Table Moun- 

 tain, and this conclusion does not rest solely on the experience of the writer 

 and of the earlier explorers <>t' the flora at Golden. The exposures of 

 Table Mountain have been studied for years by students from the School 

 of Mines at Golden, alone and under the guidance of Prof. A. Lakes, who 

 has collected so many fossil plants from this locality, and in all this time 

 hut a single vertebrate fossil lias been found (a tooth of a dinosaur) and 

 no invertebrate remains whatever. 



In the vicinity of Denver, however, mainly through the careful 

 searchings of Messrs. (i. L. Cannon, jr., and T. W. Stanton, a considerable 

 number of vertebrate fossils and some shells have been found in place in 

 typical Denver sandstones and clays. 



THE SHORE-LINE DEPOSITS. 



Besides the present limited extent of the Denver beds there are 

 certain indications that the sea in which the beds were deposited was quite 

 circumscribed, at least in its earlier stages. On the west the continental 

 land mass could not have been far away from the present foothill line, 

 though as a matter of fact there is no known evidence to show how far 

 back any of the sedimentary formations of the district may have gone. 

 But on the north and south there is evidence indicating that during the 

 first deposits of the Denver period the shore-lines were not far distant 

 from the present boundaries. The evidence in the one case lies in the 

 stratigraphic relation to the Arapahoe and in the other in a combination 

 of lithologic and stratigraphic relations. 



Within the Denver period, however, there may have been considerable 

 changes of level and correspondingly of extent covered by the sea, so that 

 the observations to he mentioned do not apply with any certainty to the 

 later stages in the history of the sea. 



Th= northern shore-une.- — lVoiii North Table Mountain eastward to the hills 

 north of Arvada, erosion has removed everything which might have 



