82 GEOLOGY OF ASPEN MINING DISTRICT, COLORADO. 
of the beds to the northwest, as seen in the section. ‘The features of the 
section are nearly like those of Section B. The northerly pitch of the Sil- 
ver fault carries it, with the associated beds, into the section for the whole 
distance from its point of outcrop on the east side of Vallejo Gulch to the 
granite on the west side of the section. It is upfaulted on the west side 
by the Saddle Rock fault, so that it outcrops in the plane of the section, 
and is again upfaulted to the west by the Pride fault so as to be carried up 
into the air and lost. The Aspen fault is shown with its slight, peculiar 
downthrust on the east side. The Schiller fault, which is here nearer its 
termination than in Section B, is shown with a throw of less than 200 feet. 
The Sarah Jane fault has about its usual downthrow of 250 feet to the 
east. The section cuts the Saddle Rock and Pride faults just south of 
their point of junction, at a point where they are very close together. The 
throw of the Saddle Rock fault is shown as about 1,100 feet down to the 
east, while that of the Pride fault can not be actually measured, since 
the granite on its west side does not afford a definite horizon, but it is 
1,200 feet at least. From the Pride fault to the Castle Creek fault there is 
nothing but granite, for the northerly dip of the beds at the northern 
termination of West Aspen Mountain carries them up into the air, so that 
only granite outcrops over the whole southern part of the ridge. At the 
Castle Creek fault, as in Section B, the overturned Triassic sandstones 
come in aud continue to the end of the section. 
RESUME OF STRUCTURE SHOWN ON THE ASPEN SPECIAL MAP. 
First. The first deformation in the rocks, changing them from their 
original structure, was folding, which is partly illustrated by the mono- 
clinal, steeply dipping strata of Section A (Atlas Sheet X). 
Second. Probably contemporaneous with this folding there occurred a 
slipping of different layers one upon the other, producing a system of 
faults nearly or quite parallel with the bedding, of which the Silver fault 
is the most important representative. These faults follow in a general 
way the folding in the rocks, and are faulted by all the other fault systems. 
Third. At some early stage in this deformation there took place a 
local uplifting of the rocks, cluding the sedimentary formations and the 
underlying granite, which produced a marked and abrupt domelike struc- 
ture. There is reason to believe that this took place at a somewhat later 
