THE REGION ABOUT GOLDEN. 101 



approximately after the deposition of about one-third of the series had 

 been completed and some time before the strata had assumed the extremely 

 high angles they now have. With regard to its relations to the phenomena 

 forming the subject of this section, it is possible that the subsidence of the 



Niobrara fold and the horizontal beds capping it may have been, in its later 

 stages, synchronous with the eruption of the basalt masses in Denver times 

 and perhaps, in a measure, due to it. The fissures through which the 

 pent-up lavas found egress may have been the result of the almost 

 constant bending to which the rocks were subjected, and their ejection 

 may have thus constituted the final event in the history of a region 

 remarkable for its dynamic movements. 



VIEWS OF OTHERS OS THE STRUCTURE OF THIS REGION. 



The views of Marvine. — These are given in Vol. VII (1873) of the Havden 

 Eeports, where he has expressed, in the briefest possible manner, the idea 

 of nonappearance of strata due to an actual "thinning of the original 

 deposits * * * from conditions naturally attending the laying down 

 of new formations upon the newly prepared and hence uneven surfaces of 

 older rocks." lie also mentions, as an alternative, the possibility of a 

 fault accounting for the structural peculiarities, lint remarks the limited 

 knowledge of the locality which he then possessed. The unpublished 

 results of his work during the season of 1874 unfortunately can not be 

 traced, and therefore his final views must remain unknown; but the brief 

 statement given above leads one to believe that he would in the end have 

 reached a solution not far different from the one presented in the foregoing 

 pages. 



The views of ward. — These are to be found in the Sixth Annual Report of 

 the present Geological Survey of the United States, pp. ,")37-538, where, 

 referring to the strata in the vicinity of Golden, between Table Mountain 

 and the Cretaceous (Montana group) — which embrace the Denver. Arapa- 

 hoe, and Laramie formations, but which are all included by him in the 

 Laramie, irrespective of stratigraphical evidence — he remarks: 



The strata are conformable, and both the Cretaceous and the Laramie are tilted 

 so as to be approximately vertical. At the base of South Table Mountain the si rata 

 are horizontal, and the line dividing the vertical from the horizontal strata could be 



