TOURTELOTTE PARK SPECIAL MAP. 115 
be obtained they are actually so, but it is possible that additional infor- 
mation might prove them to be otherwise. 
In the most important of these downthrust blocks appears the peculiar 
local syncline described in Section B. If the two are taken together it is 
seen that the beds form a true synclinal basin, in which the strata dip on 
all sides toward a common point. Between the southern end of this syn- 
clinal basin, where it is cut off by an east-west fault, and the corresponding 
sedimentary beds on the south side of the Butte fault, there intervenes the 
upthrust block which has already been referred to as having apparently not 
been affected by the movement of the Ontario fault. In this block, there- 
fore, only granite comes into the section. South of the Butte fault the 
section runs into the Cambrian quartzite again, and so continues nearly to 
the end, since the strike of the beds is nearly parallel with the section. 
This continuity is interrupted in occasional blocks, which are shifted from 
their normal position by movement along east-west faults, and toward the 
southern part of the section a slight deviation between the strike of the beds 
and the line of the section brings in the bottom of the Silurian dolomite. 
Between this point and the southern edge of the area mapped the section 
encounters three parallel east-west faults, all of which have a uniform 
upthrow to the south; and as their dip seems to be in a southerly direction, 
they are apparently reversed. These faults bring in the granite. 
Section H.— Section H runs along the ridge of the hill through a region 
of great disturbance. In the northern half of the section there is a general 
northerly pitch of the beds. The rocks are disturbed by many east-west 
faults, which have apparently no uniform movement, so that it appears as 
if the rocks had been divided by these parallel faults into blocks, which 
have moved irregularly one upon the other. 
The Copper fault, which belongs to the north-south system, has a 
westerly dip, which carries it into the section. Many of the east-west 
faults which lie to the east stop on reaching this fault, while many on the 
west side are also nonpersistent and stop at this plane. This explains 
the presentation of the faults in the section. Those which are drawn 
below the Copper fault and which stop on reaching it represent faults in 
the eastern block, while those which crop at the surface and stop in their 
downward course on reaching the Copper fault are the nonpersistent faults 
which lie in the western block. There are, however, certain ones which 
