214 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
porphyrite ; the other, a slightly porphyritic alkaline rock, with pheno- 
erysts of microcline and a groundmass composed of microcline and 
quartz in micropegmatitice intergrowth and an amphibole with the char- 
acters of riebeckite. 
Massive granitic rocks were found at each anchorage between Hamil- 
ton Inlet and Hopedale. At Sloop Harbor the hills are composed chiefly 
of a coarse hornblende granite ; Jigger Island exhibits granitites similar 
to that of the mainland; thirty miles farther north, on the mainland 
opposite Conical Island, a flow-breccia of granitite cutting diorite proved 
to be extensive. Associated with similar rocks are the only sedimentary 
formations that were seen to the southward of Hopedale. 
Sedimentary rocks at Pomiadluk Point. — Pomiadluk Point forms the 
extremity of a bold peninsula which projects northeastwardly from the 
mainland in about 55° N. Lat. Stretching along the southeast side of 
the peninsula for a distance of some five miles, is a broad bench from 
two to three hundred feet in height and from one and a half to two 
miles in breadth. On the southeast the bench falls into the sea quite 
abruptly ; on the northwest it ceases at the foot of a steep ridge of 
granitite that composes the main part of the peninsula. Barometric 
readings on two different days accorded well in giving eleven hundred 
feet as the elevation of a prominent summit of the ridge. Its average 
height is not less than one thousand feet; toward Cape Strawberry it 
rises to twelve hundred feet, and is thus the highest land encountered 
on the coast between the Cape and the straits of Belle Isle. 
The glaciated ledges of the flat though hummocky bench have been 
wave-swept during postglacial submergence and thus one can study the 
rock-composition and structure with exceptional ease. The bench is 
conterminous with a well exposed mass of metamorphic conglomerate. 
Along four cross-sections about a half a mile apart, the sedimentary band 
was proved to be very homogeneous. In a silicious matrix, often highly 
schistose, pebbles and boulders up to one or more feet in diameter are 
embedded. They are composed of granitite, quartzite, vein quartz, 
granite porphyry and metamorphic sandstone. They are almost always 
considerably flattened, though the granitite pebbles have oftentimes so 
far resisted the shear as to present still well-rounded outlines. The 
schistose structure strikes steadily N. 15° W.; its dip is variable but 
steep and generally to the westward. Not allowing for duplication, the 
thickness of exposed conglomerate measured on this secondary structure- 
plane was estimated at eight thousand feet. On the west the conglomer- 
ate becomes finer-grained and for a distance of three hundred feet from 
— 
