Dikes. 
229 
of the dike and did not develop schistosity as in the case of 
dike no. 1, whose strike was at right angles to the force. In¬ 
stead of producing schistosity it folded and faulted the dike. 
The rock microscopically is light gray and fine grained, con¬ 
taining small crystals of red feldspar, octahedra of magnetite, 
no ferro-magnesian minerals. The rock resembles the altered 
portion of dike no. 1, though it is more metamorphosed than 
that rock. 
The rock is now so altered and decomposed that its original 
character is indeterminable when examined by itself. Its iden¬ 
tity with the altered portion of dike one leads to the conclusion 
that originally both were the same type of igneous rock. Dike 
no. 2, on account of its small size and its fractured and jointed 
condition, was especially liable to secondary changes. So com¬ 
pletely have these operated that very few traces of the original 
structure remain. 
Dike No. 3 .—This igenous rock cuts the schists of Lion’s 
Head, and like its neighbor, dike no. 2, it follows the cleavage of 
the schist, which dips 30° N. 60° E., the strike being N. 30° 
W. The width varies from 2 to 7 feet. It is very much 
faulted and jointed. The fault planes lie across the strike, the 
throw is rarely over 4 or 5 feet, but in a few cases it is much 
greater, the fault planes show slickensides clearly, but their di¬ 
rection is so nearly parallel to the dip of the dike that the 
amount of throw can not be estimated. In its macroscopic and 
microscopic characters the rock is similar to dike no. 2. Their 
identical structure and their similarity of occurrence all indi¬ 
cate that the two dikes, if not one arid the same, are yet closely 
allied. 
Dike No. J /..—This dike intersects the schists of the west 
shore, striking N. 30° E. and dipping 40° W. N. W., its dip 
agreeing w ith that of the schistosity. It contains a core of bi- 
otite rock similar to dike no. 1. The outside is altered to the 
now familiar light colored rock, which consists largely of feldspar, 
calcite and muscovite. The dike has not been folded because its 
direction of least resistance is nearly parallel to the folding 
forces, but schistosity has been extensively developed within it. 
Back from the shore where this dike occurs and some forty rods 
