110 GEOLOGY OF ASPEN MINING DISTRICT, COLORADO. 
planes is very great and can not be precisely ascertained, but on some of 
them the movement has been much greater than on others, and along such 
planes it has been found advisable to represent the total movement as 
having occurred. The two faults shown in the section have actually been 
traced over nearly the whole southern part of the area of the Tourtelotte 
Park special map (Atlas Sheet XII). The western one may be called 
the Annie fault, and the eastern one the Dubuque fault, from their being 
best shown, respectively, in these mines. Faults of this character may be 
called dependent faults, since they are really parts of the main or master 
fault, which in this case is the Castle Creek. Owing partly to the action of 
these dependent faults, and partly to the change m attitude of the beds on 
the west side—partly, also, to the somewhat lower position of the rocks on 
the east side—the entire throw of the Castle Creek fault has considerably 
diminished from that shown in Section A. 
East from the Castle Creek fault the Cambrian quartzite is soon 
encountered above the granite. This is in turn overlain by the Silurian 
dolomite, which extends as far as the Saddle Rock fault. This fault has 
its usual downthrow to the east, and places the outcrop of the Carbon- 
iferous dolomite adjacent to that of the Silurian. Farther up the hill 
comes the Silver fault, with the thin strip of crushed shale which separates 
the Leadville limestone from the main sheet of porphyry. Close to this 
point the Sarah Jane fault is encountered, with its usual downthrow to the 
east. East of this fault is shown the remnant of the Aspen Mountain 
syncline, in a position corresponding to that in Section A. This is practi- 
cally continuous and unbroken as far as the Justice fault. Between the 
Justice and the Sarah Jane faults is a slight displacement, arising from 
the Good Thunder fault. his fault belongs to the east-west system, but, 
on account of an irregular crumpling in this plane, actually cuts the section 
as represented. In the 300-foot section (see Section F, Atlas Sheet 
XXIJID, along this same line, the fault is more accurately represented 
as intersecting the plane of the section m two lines, but in the 800-foot 
section the intersection has been represented, for the sake of simplicity, as, 
in a single line. The Justice fault has its usual downthrow to the east and 
is cut at the place where its throw has been best measured. Immediately 
east of the Justice fault the main sheet of porphyry cuts up across the 
bedding of the Weber shales, leaving a considerably increased thickness of 
