ASPEN DISTRICT MAP. 135 
On the northern edge of West Aspen Mountain there is shown on the 
map a series of cross fractures, which represent the slipping of the rocks 
on the northern end of this block over each other while the southern end 
of the block was being upthrust. The bending of strata and the faulting 
were apparently developed at the same time and extend over practically 
the same area, so that they are both probably the manifestation of a single 
force, which tended to push the beds upward. The point of greatest 
uplift, which is situated at about the top of Aspen Mountain or in North 
Tourtelotte Park, is also the point of most intense faulting. The steep 
northerly pitch on the north side of Aspen Mountain continues up to the 
top of the mountain, or to the point of greatest disturbance. At this point 
the attitude of the beds changes again somewhat abruptly, so that they 
have no pitch, or a slight southerly one, and this attitude persists to the 
southern edge of the district. Since on the west side throughout this same 
district the uniform northerly pitch continues, it results that from Aspen 
Mountain the displacement of the Castle Creek fault steadily diminishes 
toward the south. 
The amount of faulting at Red Butte has been computed at about 
2,600 feet. On Aspen Mountain, near the center of greatest uplift, the 
section shows a throw which has been increased by the differential dip of 
the beds to the east and to the west of the fault, and by the upfaulting 
of blocks immediately to the east to about 9,000 feet. South of this 
point, however, the throw steadily decreases again, until near the southern 
edge of the area it is only about 2,600 feet.. It appears from this that the 
amount of movement along the Castle Creek fault has been about the same 
at Red Butte and at Queens Gulch, while in the intervening space there 
is a great, but purely local, increase, so that the throw becomes three and 
four times as great as in these two places. ‘This crease is apparently 
independent of the beds on the west of the fault, and is caused simply by 
the uplifting of the dome which has been described on the east side, and 
which has its center of greatest disturbance at the point of maximum 
displacement along the fault. . 
In the interval between Roaring Fork and the top of Aspen Mountain, 
the longitudinal section (Section G, Atlas Sheet VII) shows an uplift along 
the strike amounting to about 5,000 feet, caused by the combined effects 
of folding and heavy faulting. The difference in the displacement of the 
Castle Creek fault between the point where it is displayed at Red Butte 
