SMUGGLER MOUNTAIN. 181 
hoven tunnel is a little farther to the left. In the gulch on the mountain 
side is the dump from the Johnson tunnel, which now forms part of the 
Della S. mine. 
MOLLIE GIBSON MINE. 
The so-called “contact” in the Mollie Gibson mine, along which most 
of the exploration for ore is made, is the Silver fault, which here separates 
the Leadville dolomite from the Weber shale. Between these formations 
there is a thick breccia containing fragments of blue limestone and occa- 
sionally of ore. An interbedded sheet of porphyry lies in the contact near 
the shale, sometimes separated from the dolomite by 20 or 30 feet of shale, 
sometimes resting directly against it. This is the situation from the 
Smuggler line on the north to a point 1,300 feet south of the Mollie 
Gibson shaft, where the edge of the blue limestone comes in between the 
shale and the dolomite. From this point the limestone wedge broadens 
very slightly toward the south, so that probably 40 or 50 feet is the 
maximum thickness in the Gibson workings. From the point of appear- 
ance of the blue limestone there are two “contacts,” one between the 
brown dolomite and the blue limestone, and the other between the blue 
limestone and the shale. The former is the Contact fault, which is cut off 
by the Silver fault at the pomt where the blue limestone disappears to the 
north. The latter is the Silver fault, as before. Both these faults are 
marked by a crushed zone of rock, with polished walls. From the point 
of junction of the Contact and Silver faults southward the Contact fault is 
generally prospected for ore, although there is no reason why the Silver 
fault should not also be productive. 
Gibson fautt—The Gibson fault, which belongs to the Della system, is 
displayed in every level of the Mollie Gibson. It has an east-west strike 
and a southerly dip of about 30 degrees, and faults both the Silver and the 
Contact faults. The lateral displacement or perpendicular separation of 
these earlier faults by the Gibson varies at different levels, showing that 
the latter fault diminishes with depth. In the fourth level the separation is 
about 105 feet, in the eighth about 70 feet, and in the tenth about 50 feet. 
Emma fault—Qn the seventh level, 220 feet north of the Gibson, is a 
fault having the same attitude and direction of movement. This move- 
ment, which is to the west on the north side, results in a perpendicular 
separation of about 35 feet. The fault is also shown in the ninth and 
