119 
pearance of this dike to the e: stward is on the shore of Straits 
Pond, more than a mile from its starting point. On Melaphyr 
Plateau it appears to give off a branch (32), which ean be 
traced for a considerable distance parallel with the main dike. 
Granite Head on Rocky Neck is crossed near the northern 
edge by a double dike (34) having a northerly hade of 50° and 
the following section from south to north: main dike, 7 to 8 
feet; granite parting, 6 to 18 inches; small dike, 15 inches 
(Fig. 15). It can be traced entirely aeross the head, and 
presents the same section and hade in each escarpment. This 
dike crosses the valley occupied by the boundary fault without 
sensible displacement and reappears on the opposite slope at the 
point where it erosses the great N. E.-S. W. fault, which here 
downthrows to the southeast. There are indications, however, 
that the dike is subsequent to the fault and has simply been 
jogged in erossing it; for it is shifted or jogged to the north 
some 50 feet in crossing the fault. If the fault were subse- 
quent to the dike, the displacement should be in just the oppo- 
site direction. The character of the dike is unchanged, except 
that it is simple instead of composite, no trace of the smaller 
member being observed. On account of the hade, the outerop 
curves in passing down the hill to the shore ; but it is not clear 
enough to determine with certainty its relations to 22. Crossing 
Weir River Day in the same direct line, and apparently without 
displacement, it reappears as a double dike with a strong 
northerly hade (40?—50^) on the southwest corner of West Por- 
phyrite Hill The section here from south to north is: diabase, 
3 feet ; conglomerate, 8 feet ; and diabase, 7 feet. The hade is 
most marked in the southern member, which is possibly a 
branch of the other, but more probably an independent dike ; 
for оп Cliff Plateau they are reversed in position, the small 
dike, which is now on the north, retaining its stronger hade. 
Near the eastern edge of the plateau it suddenly disappears, 
apparently joining 22 ; possibly, however, it is continued along 
a more northerly line by the other inclined dike (31). The 
