ASPEN SPECIAL MAP. 81 
e 
on the east. ‘This blue limestone makes its first appearance in the space 
between Section A and Section B, under the Roaring Fork Valley, as 
shown in the Mollie Gibson workings. South of this point it always lies 
below the Silver fault, while to the north it is as uniformly absent. The 
Silver fault is downfaulted beyond the scope of the section by the Schiller 
fault, and continues below the plane of the section as far as the Pride fault, 
when it is upfaulted so far that it has been entirely removed by erosion 
on West Aspen Mountain. The Mary B. fault throws down the rocks on 
its west side so that the Silver fault is again brought far below the plane of 
the section, and the Castle Creek fault thrusts it down still farther. It is 
visible, therefore, only in a narrow strip between its outcrop in Vallejo 
Gulch and its termination against the Schiller fault. 
In this section the Schiller fault has a heavy downthrow on the west 
side of about 600 feet, while the Sarah Jane fault, lying next west, has its 
usual slight downthrow on the east of about 200 feet. The Pride fault has 
a throw of about 2,000 feet, so that on the east side of the fault at its out- 
crop are Weber shales, and on the west is granite. ‘The section next passes 
diagonally through the point of West Aspen Mountain. The obliquity of 
the section makes it appear as if the beds on West Aspen Mountain were 
dipping away from the Aspen Mountain syncline, while in reality they have 
a general dip toward it, although the actual dip is more to the north than 
to the east. 
The east-west northerly dipping faults of West Aspen Mountain are 
also shown in the section, and the Mary B. fault is cut not far from its 
junction with the Castle Creek fault, a little distance to the south. Here 
the basal limestone of the Maroon comes in just above the contact with the ~ 
Weber. At the Castle Creek fault the easterly dipping reversed red sand- 
stones of the Triassic come in and are continuous to the end of the section, 
except where covered with wash. As shown in the section, the Mary B. 
fault has a downthrow on the northwest side of about 2,000 feet, while the 
throw of the Castle Creek fault, as roughly estimated by the distance from 
the middle of the Triassic to the bottom of the Maroon, is 5,300 feet or more. 
Section c—Section C (Atlas Sheet X) cuts across the southwest corner of 
the Aspen special map, parallel with and only a short distance from Section 
B. Asin Section B, the plane crosses the Aspen Mountain syneline at an 
angle, so that the northerly pitch of the syncline causes the general inclination 
MON XXKI——6 
