242 
ACCOUNT OF 
Proceeding from the north point of the island to the 
eastward, the strata have their direction IT W. of N.; 
when two-thirds across the open bay, the sandstone begins 
to rise towards the promontory (B), its direction and dip 
bending round at right angles to their former bearing. Its 
rise towards B is at first very gentle ; but near the point 
(a) the dip rapidly assumes an angle of 70°, where a small 
gully divides the sandstone from the primary rocks ; and, 
on the east side of the gully, an apparent chaos of primi- 
tive rocks meets the eye ; thick tortuous beds or veins of 
graphic granite intersect gneiss and mica-slate in the most 
fantastic manner; and veins or beds of quartz, of a calcedonic 
appearance, of a foot and more in thickness, tend to increase 
the variety. An attentive examination, however, shews, 
that the gneiss and mica-slate, and even the granite veins, 
have a general tendency to one direction and dip ; and a 
view of the east side of the rock A, which accompanies this 
description, will shew the nature of the association. The 
dip is a little to the E. of S. The granite veins, however, 
are not always parallel with the dip of the strata ; on the 
contrary, as is seen in the section of the rock A, they 
sometimes intersect them at right angles. I observed in one 
place a section, in the direction of the stratification, display 
two curved veins of granite, inclosing a portion of mica- 
slate. 
At the promontory B, the mica-slate contains much horn- 
blende, and in some places is studded with garnets. Fel- 
spar occurs also between the layers, by which means it 
passes into gneiss, to which it seems subordinate. On the 
east side of the promontory B, all appearance of gneiss and 
mica-slate is lost, and an unstratified mass of fine-grained 
graphic granite extends for half a mile along the coast to 
the point C. This granite is of the same nature with the 
veins already mentioned ; the felspar, which is in excess. 
