ASPEN DISTRICT MAP. 139 
on the left is Red Butte itself, although the different formations can not be 
distinguished. In the distance the uniform, gentle, north-facing slope of 
the hills is identical with the dip of the rocks which form the north limb 
of the gentle anticlime referred to. 
The section as described seems to show that at the point of maximum 
disturbance there once existed a sharp, compressed anticline, which was 
overturned to the west, and that along the axis of this anticline the great 
fault developed. It is a marked feature of this folding, as compared with 
that of other closely folded areas, that it is confined to a narrow zone, east 
and west of which the beds are comparatively undisturbed. 
Section D.—Section D passes through the central portion of the uplifted 
area in Tourtelotte Park. In this area are shown the minor folds and the 
numerous faults generalized from the special maps, and east of this there is 
nothing but Archean granite. In this section the Castle Creek fault sepa- 
rates the granite from the Triassic sandstones, its vertical displacement 
being about 9,000 feet. The beds west of the fault are still overturned, 
having a steep easterly dip. The structure of the ridge which lies between 
Maroon Creek and Castle Creek shows that here there is a slight anticlinal 
which has no counterpart in Section C. In the western part of the section 
the beds have a gentle easterly dip, which corresponds to the similar dip 
in the western part of Section C. The outcropping Dakota sandstone runs 
along the surface west of Maroon Creek. 
Section E—'The extreme east end of the section is somewhat beyond the 
limits of the map, bemg the point where Difficult Creek runs into Roaring 
Fork Valley. At this place is granite, which continues to near the top of 
Richmond Hill. The strata exposed on this hill belong to the lowest por- 
tion of the sedimentary series, and constitute a west-dippine monocline. 
The faulting connected with the Tourtelotte Park uplift is also shown. West 
of the Castle Creek fault the beds are still slightly reversed, having an east- 
erly dip which approaches the vertical. It is near this point, however, that 
‘the beds overturn and resume their normal succession. The Weber forma- 
tion outcrops directly west of the fault, being brought up by the northerly 
pitch of the fold, and from here to the top of the mountain between Castle 
Creek and Maroon Creek there is apparently nothing but Maroon beds, but 
the top seems to be formed of the heavier and brighter red Triassic sand- 
stones. The syncline, in the bottom of which, as in the previous section 
