272 
ELDRIDGE. 
an actual “ thinning of the original deposits * * * from 
conditions naturally attending the laying down of new for¬ 
mations upon the newly prepared and hence uneven surfaces 
of older rocks.” He also mentions, as an alternative, the 
possibility of a fault accounting for the structural peculiari¬ 
ties, but remarks the limited knowledge of the locality which 
he then possessed. The unpublished results of his work 
during the season of 1874 unfortunately cannot 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. 537—’8, where, referring to the strata in 
the vicinity of Golden, between Table Mountain and the 
Cretaceous [Montana group]—which embraces the Denver, 
Arapahoe, and Laramie formations, but which are all in¬ 
cluded by him in the Laramie, irrespective of stratigraphical 
evidence—he remarks as follows: “ The strata are conform¬ 
able, and both the Cretaceous and the Laramie are tilted so 
as to be approximately vertical. At the base of South Table 
Mountain the strata are horizontal, and the line dividing 
the vertical from the horizontal strata could be detected at 
certain points. A measurement from this line to the base of 
the coal seam was made at one place and showed 1,700 feet 
of upturned edges of Laramie strata. It is probable that we 
here have the very base of the formation. 
“ The geology of Golden is very complicated, but my ob¬ 
servations led me to conclude that during the upheaval of 
the Front Range a break must have occurred along a line 
near the western base of Table Mountain, forming a crevice 
through wdiich issued the matter that forms the basaltic cap 
of these hills. The eastern edge of a broad strip of land 
lying to the west of this break dropped down until the entire 
strip of land assumed a vertical position or was tilted some¬ 
what beyond the perpendicular. This brought the Laramie 
