114 GEOLOGY OF ASPEN MINING DISTRICT, COLORADO. 
In this section the diorite is slightly higher in position than in any of 
those farther north. It has attained about the horizon of the Parting 
Quartzite, which it frequently cuts across, and small bodies of which it 
sometimes surrounds. Its thickness is probably about the same as that of 
the Parting Quartzite itself. 
Section F—In this section the beds west of the Castle Creek fault are 
seen more fully restored to their normal succession. The chief dependent 
faults—the Annie and the Dubuque—both outcrop. The convergence 
toward the south between the trend of the Castle Creek fault and the line 
of contact between the granite and the overlying sedimentary beds has so 
reduced the distance between the Castle Creek fault and the granite in this 
section that it is very slight. The northerly pitch of the beds, moreover, 
has brought to the surface successively lower and lower formations, so that 
in this section the highest horizon east of the Castle Creek fault is that of 
the Parting Quartzite. The Parting Quartzite, however, is not represented 
in the section, for the diorite sheet, here apparently as much as 100 feet 
thick, has superseded and traversed the Parting Quartzite until the exact 
position of the latter is not recognizable. Thus the place of the Parting 
Quartzite is occupied by the diorite, and above the diorite the Leadville 
formation comes in. Below the Silurian dolomite on the east side of the 
hill the Cambrian quartzite is continuous to the Ontario fault. This fault 
brings down into the section the very bottom of the Silurian dolomite, 
which passes immediately across the Cambrian quartzite into the granite. 
The fault represented just below the contact of the Cambrian quartzite with 
the granite is a nonpersistent north-south fault, which has some slight 
upthrow to the east. The last fault shown in the section as outcropping in 
the granite on the side of the hill is one of the series of east-west southerly 
dipping faults. 
Sections G, H, and I (Atlas Sheet XV) are north-south sections, run- 
ning at right angles to the six sections which have already been described. 
section G.—This section starts in granite on the slope of Hast Aspen 
Mountain, just above Roaring Fork Valley, and at a little distance south it 
runs into the north-pitching series of sedimentary beds. The pitch of 
these beds tends to carry them into the air, but they are continually thrust 
down toward the south by parallel east-west faults. These faults are 
shown in the section as reversed, and from all the information that could 
