ASPEN MOUNTAIN. 157 
association of ore with dolomite is almost invariable, its occurrence in an 
unaltered blue limestone is extraordinary. 
Schiller mine —The Schiller workings lie just west of the Durant, and the 
ore-bearing horizon occurs somewhat lower down. The mine is reached 
by the Schiller shaft, and also by the Schiller incline, which runs from the 
Durant workings. The Schiller shaft passes through about 390 feet of 
porphyry and 190 feet of broken porphyry and shale to the bottom, which 
is in the Silver fault. From the shaft an incline runs down through the 
Silver fault, across the blue limestone, to the Contact fault. The Schiller 
fault runs in dolomite from the 200-foot level of the Durant down to the 
level at the bottom of the Schiller workings. This level runs off to the 
south in dolomite to the breast, where a bed of quartz and black dolomite, 
with a fine material strongly resembling the Parting Quartzite, is encoun- 
tered. The Schiller fault runs through the foot of the incline from the 
Durant in a nearly vertical line with a north-south trend. There are one 
or two parallel slips near the Schiller fault, evidenced by slickensides and 
fissures filled with fine clay, and the Contact slip is shown in the lower 
workings. Along these several faults ore has formed and has been stoped 
out at intervals. : 
The Aspen Mining and Smelting Company mine——This mine, currently called the 
A. M. and §., is reached by the Veteran tunnel, which cuts through the 
glacial drift to a point close to the Franklin shaft, where it enters Weber 
shale. It soon after crosses a thin bed of blue limestone and enters the 
Contact fault. The formations in the A. M. and 8. are the same as in the 
Aspen and the Durant, but the great local steepening and overturning of 
the, beds noted in the mines just described is here absent. There is, it is 
true, a slight steepening, but, so far as exposed, the dip is fairly uniform 
from the outcrop down to the bottom of the workings, being about 35 or 
40 degrees. The Silver fault is shown in the tunnel, where the zone of 
shale above the blue limestone is very much crushed, and also at several 
other places in the lower workings. In this mine the Silver fault cuts down 
across the formations so that the blue limestone becomes quite thin. The 
Contact fault between the blue limestone and the underlying dolomite is 
well shown, the brecciated zone along it being often thick and conspicuous. 
A feature of the Contact fault which is not noted in the most of Aspen 
Mountain is the presence of bowlders of porphyry in the breccia, these 
