74 GEOLOGY OF ASPEN MINING DISTRICT, COLORADO. 
to the west. There is, therefore, no uniform displacement, but the blocks 
formed between the faults have simply moved up or down to accommodate 
some lateral stress. 
There is no definite system of east-west faults on Aspen Mountain. 
A few faults which have this trend are apparently local cross fractures, 
which have no great persistence, and whose characteristics show that they 
were probably developed at the same time as the north-south faults, This 
includes the faults on the point of West Aspen Mountain and those of the 
Bonnybel and Chloride group. 
On East Aspen Mountain there is a system of north-south faults which 
is quite different in age and nature from the Aspen Mountain system. This 
system has its greatest development in Tourtelotte Park and is later than 
the ore deposition. 
SMUGGLER MOUNTAIN. 
In Smuggler Mountain there is no sign of any continuation of the 
Aspen Mountain syncline, but the beds all dip uniformly and steeply to 
the northwest. The amount of faulting is also greatly diminished, and the 
important north-south faults of the Aspen Mountain system are not found. 
There are, however, several minor systems of faults, which, on account of 
their difference in age, their great variation in attitude and in direction of 
throw, and because they have often all acted im the same area, are very 
puzzling. 
Silver fault——The Silver fault is present throughout the whole of Smuggler 
Mountain. In the Mollie Gibson mine, at a locality beneath the Roarmeg 
Fork Valley, it cuts out the blue limestone, and therefore obliterates the 
Contact fault? from this point north. The mines follow the Silver fault as 
the chief ore-bearing locality, and find all along it more or less mineraliza- 
tion. It is marked by a heavily brecciated zone, with solid shale and 
sometimes a thin band of porphyry on the west or upper side, and Leadville 
dolomite on the east side. It cuts down into this dolomite and nears the 
Parting Quartzite just before leaving the area to the northeast. 
Detla fault——The Della fault has an east-west trend and a southerly dip 
of about 30 degrees from the horizontal. The beds on the under side 
of tae pleite are faulted to the west, and the striz show that the actual 
: The Contact fault runs coarse 0 in bedding and separates the blue limestone from the 
dolomite of the Leadville formation throughout a large part of the district. 
