68 GEOLOGY OF ASPEN MINING DISTRICT, COLORADO. 
considered as taking place along the two planes which form the opposite 
boundaries of the wedge, and to these planes the names Bonnybel and 
Chloride faults have been given. These two faults may be described as 
slightly converging both to the northwest in their trend and downward 
in their dip, hence they may soon come together in either direction and 
form a single plane, or, more properly speaking, a narrow zone of fracture, 
which finally runs into the Silver fault and there terminates, so far as can 
be traced. The general movement of these two faults is to thrust down 
the block between them relatively to the surrounding beds. This move- 
ment is best seen by the position of the Parting Quartzite, which between 
the faults outcrops farther down the Iill than it does on either side of 
this downfaulted block. The maximum amount of this throw may be put 
at about 150 feet. 
These faults, and indeed the whole of the highly fractured wedge 
between them, have been intensely mineralized, and therefore the move- 
ment was premineral. The faults are not traced very far to the southeast 
from the point where they leave the area of the Aspen special map. The 
Bonnybel fault is represented on the Tourtelotte Park special map (Atlas 
Sheet XII) as terminating at a minor intersecting fault, while the Chloride 
fault is represented as running into the Justice near the pomt where that 
fault unites with the Copper fault. Both the Justice and the Copper faults, 
however, have a somewhat different trend, which is north, instead of north- 
west, and both of these faults belong to a distinct system from those 
which have been described on Aspen Mountain. This system is character- 
ized by having its greatest development in Tourtelotte Park, while the 
Aspen Mountain system has its greatest development on Aspen Mountain, 
and by the fact that the greatest displacement took place subsequent to 
the period of ore deposition, while in those of the Aspen system it took 
place previous to this period. 
Vhe Chloride and Bonnybel faults are therefore quite distinct in point 
of age from the Justice and Copper faults, and if the Chloride fault 
actually runs into the Justice, as it seems to do, they still must be considered 
as belonging to separate systems. It is probable, however, that the 
original fracture, which was formed at a very early date, was actually 
continuous along the planes now occupied by the Chloride and Justice 
faults, and that in the case of the Chloride fault the maximum displace- 
