LENADO SPECIAL MAP. 1233 
the northern side of the fault is nearly three-quarters of a mile away to the 
northeast. The’ Lenado fault is cut in the Leadville and Aspen Contact 
mines. Just above the Leadville mine it is shown in the Daisy and Ajax 
tunnels, which run into it on opposite sides of the gulch. Farther on 
the fault crosses the cliff on the south side of the granite gateway, in the 
little sag shown in PI. XI, and from here apparently runs across the gulch 
in granite so as to cut off the quartzite on the northern side of the 
canyon. This last point is not shown on the map, but may be seen in 
lel, 2UE 
This fault, as estimated in Section B (Atlas Sheet XX), has about 
1,300 feet vertical downthrow on the north side. The result of its displace- 
ment, as seen on the map, is a shifting of the formations to the east on the 
north side. The formations exposed on the south side of the fault abut on 
the north side always against formations which are stratigraphically above 
them. Thus, at the Aspen Contact mine, Cambrian quartzite on the south 
lies against the Weber shales on the north. There are in this place, as 
probably all along the fault, a number of parallel slips, which are close 
together, and which divide the total throw between them. In the Aspen 
Contact mine there are two faults close together, the most northerly of 
which has shale on the north side and dolomite on the south side, while the 
one next south has dolomite resting against quartzite. In the general 
description and mapping, however, these parallel faults are considered as 
one, and it is in this sense that the statement that the shales rest directly 
against the quartzite must be taken. 
It is probable that the total displacement of the rocks occasioned by 
this fault was actually a nearly vertical downthrow to the north of about 
the distance mentioned, without any great lateral movement, for the lateral 
offset of the beds as now seen in outcrop is almost exactly the amount by 
which the beds would separate from the results of a vertical throw. This 
arises from the fact that the beds all have a steep dip of 35 or 40 degrees 
to the west, so that the downthrust of the formations on the north side of 
the faults causes the contact to advance a certain distance to the east, in a 
direction opposite to that of the dip. The amount of this advancement 
depends upon the angle of the dip of the beds, and upon the vertical throw. 
The distance by which the outcrops of such beds would travel to the east 
on the north side of the fault has been computed at an average dip of 30 
