Gil! B— ON CANADIAN OAVEliXH. 
175 
on the south shore, which is here ten and a-half miles across. (See 
skeich, plate ix.). 
The prevailing rocks around ^lurray Bay belong to the Laurentian 
formation, their gneissic character being distinctly displayed in a 
set of beds on the west side of the bay above White Cape, marked 
by diversities of colour allied to red, gi-een, black, and white ; these 
beds are described as granitic but very quartzose, with some bands 
among them possessing the aspect of a slightly micaceous quartz 
rock. Among the beds is a large grained red gTanitic dyke, running 
in general with their strike, which is north-west, at an angle of from 
thirty to thirty-five degrees. On the east side of the bay, near Les 
Ecorchis, the gneiss presents the aspect of a dark grey compact 
shghtly micaceous hornblende slate. It is here also cut by a very 
coarse-grained dj'ke, mnning generally with the stratification, and 
consisting of quartz and opaque white felspar, while hornblende pre- 
vails on each side of the dyke towards its contact with the gneiss. 
Still further to the eastward, before reaching La Hen, there is a very 
great white dyke of a similar character. No interstratified bands of 
crystalline limestone belonging to the Laurentian formation are here 
met with. The Potsdam sandstone, or white quartz rock, appears 
above White Point, and at two spots at the east side of the bay. At 
White Cape the calciferous sand rock is next observed ; it composes 
the point which bounds the boat cove on the south. The beds here 
are about twenty -tkree yards broad with a thickness of fifty-eight 
feet, and the rock is descr-ibed as a calcareous sandstone, possessing 
arenaceous layers intersti^atified with occasional bands of limestone ; 
the last forms the uppermost bed as well as a few at the bottom. Li 
some of the arenaceous beds translucent milky quartz-pebbles exist 
as large as hens' eggs, thus constituting them into conglomerates ; 
but the grains are generally of such small size as to give an oolitic 
appearance to the rock : they consist both of limestone and quartz.* 
Dr. Bigsby found some of the nodules as large as a child's head. To 
the west of the boat cove are two hummocks of the rock, forming the 
bluff from which White Cape takes its name. 
The conglomerate which thus composes the chief part of the preci- 
pice of White Cape is described by Dr. Bigsby as in strata more than 
a foot thick, abutting against mica slate in various unconformable 
positions. — " At the west end the layers are very thin, and are placed 
vertically, with a south-west direction, in some degree of parallelism 
to the contiguous mica slate. Near this they are contorted, until 
gradually toward the centre of the range they become horizontal. 
Here a singular disposition of the upper laminse is obsei-ved. They 
roof a shallow cave in undulating lines, which descend gently from 
above, and after curving upwards for a short distance, decline sud- 
denly on the horizontal strata which constitute the lower half of the 
sides of the cave."t (See sketch, plate ix.). 
* Geo). Survey of Canada. Repovfc for 1849-50. 
f Amor. Jour, of Science, vol. v., p. 212. 1S22. 
