182 GEOLOGY OF ASPEN MINING DISTRICT, COLORADO. 
tenth levels, and is probably the same as that which cuts the 40-foot level 
of the Smuggler. 
Smuggler faultt—The Smuggler fault comes into the Mollie Gibson mine on 
the ninth level north. At this point the perpendicular separation of the 
Silver fault by the Smuggler is about 70 feet, showing that the latter fault 
increases as it goes down. 
Della fault—The Della fault just cuts the end of the tenth level north in 
the Mollie Gibson mine, and is not otherwise displayed in the workings. 
Clark faut——There is evidence tending to show the existence of a fault 
nearly parallel with the Silver fault and only a short distance from it. 
This fault has displaced the original ore bodies which formed after the 
development of the east-west southerly dipping faults. This fault is recog- 
nized throughout the Mollie Gibson and Smuggler by the mine managers, 
and is called the Clark fault. On the fifth, sixth, and seventh levels of the 
Mollie Gibson it has been identified as a highly fractured zone, with dolomite 
on both sides, not far away from the Silver fault. Its general effect is an 
upthrow on the east side, so that the apparent dip of the ore-bearing rocks 
becomes much steeper. It is probable that this fault is not a single plane, 
but is rather a broad zone made up of many parallel faults, each of which 
has a downthrow on the west. In the upper workings of the Smuggler. 
mine several of these parallel faults may be recognized, with the effect on 
the general dip which has been mentioned. On account of the approximate 
parallelism between the Clark and the Silver faults the former often lies 
between dolomite and shale, and in this case can not always be distinguished 
from the Silver fault. The best evidence which is offered as to the nature 
of this fault is the displacement of the peculiar ore bodies in the Smuggler 
and Mollie Gibson mines. The main Mollie Gibson ore body consists of a 
peculiarly rich ore, which contains a large amount of polybasite and native 
silver inclosed in flesh-colored barite, locally called pmk spar. This ore 
occurs along the uppermost of the Della system of faults—the Gibson. 
Northward along the fault comes in lead and silver ore, not so high in grade, 
and finally ore very rich in zine, such as is found only in a restricted region 
here and ina similar restricted region at Lenado. ‘This zine ore, consisting 
of mingled sulphides and carbonates, is found in the uppermost level of the 
Smuggler mine and crops at the surface in an open cut. In the Mollie 
Gibson the rich polybasite ore is cut off on the west side at the contact with 
