112 GEOLOGY OF ASPEN MINING DISTRICT, COLORADO. 
the usual displacement. 'The increased throw of the Sarah Jane and the 
apparent reversed movement of the Justice are, as before explained, due to 
the downfaulting of the wedge included between these two faults near 
their intersection. The first fault east of the Justice is apparently slight, 
and is probably a nonpersistent cross fault, having a northwest trend. It 
is marked in the topography by a continuous scarp, and seems to haye a 
slight downthrow to the northeast, as represented. 
East of this fault the continued westerly dip brings the Silurian lime- 
stone into outcrop. On the eastern slope of the hill the Copper fault is 
encountered in its usual position, with its maximum development. Its 
movement is an upthrow to the east, so that the Cambrian quarzite rests 
against the Silurian dolomite. Below the quartzite granite outcrops along 
the section plane till the east-west Butte fault is obliquely intersected. On 
the south side of this fault come again the Silurian dolomite and Cambrian 
quartzite, which in turn give way to the granite 
In this section the only shale is that in the little downthrust block 
between the Justice and the Sarah Jane faults, and there is no porphyry 
whatever. This is due to the northerly pitch of the beds, which carries 
the strata successively above the surface toward the south. The diorite 
sheet. has in this section taken up its place in the middle or near the upper 
part of the Silurian dolomite, having cut up across the strata in the distance 
intervening between this section and Section B. 
Section D— West of the Castle Creek fault in this section the beds change 
at their point of outcrop from their reversed easterly dip to their normal 
westerly one. Hast of the fault the Cambrian quartzite and the lowest 
part of the Silurian dolomite outcrop. The next fault encountered runs 
north and south, and is probably the Saddle Rock. This has a slight 
downthrow to the east. ; 
The first of a series of east-west trending faults, which have a dip 
toward the south, is next cut. On account of their dip, these faults cut the 
plane of the section im nearly horizontal lines, as represented. The fact that 
both the east-west and the north-south faults cut the same section explains 
the somewhat complicated structure here shown. The Justice fault, which, 
after uniting with the Sarah Jane, probably dies out against one of these 
east-west faults, outcrops at this point a little to the north of the line of 
the section, and does not, therefore, cut this section plane at the surface; 
