‘On the northern shore of Mistake bay, nine miles west of Term point, is a long point of similar diabase. Seven miles further southwest, about the middle of the west shore of Mistake bay, is a high point of similar dark-green diabase, containing in many places a large amount of copper-pyrites, and cut by small veins of quartz studded with iron pyrites.’
‘Two miles south of Sir Biddy island is a prominent rocky point, with a high rocky island lying a short distance off it. From this prominent point the shore turns westward, and is bold and rocky, being composed of dark-green fine-grained diabase, studded with copper-pyrites.’
The above extracts from Tyrrell’s report show that on his hurried journey southward from Chesterfield inlet he found Huronian rocks occupying the shores of the bay for a distance of nearly a hundred miles. At haphazard landings along this shore traces of copper deposits were found in a number of places, and these would point to important discoveries as likely to follow systematic search on this area.
A considerable amount of magnetic pyrites was found in the squeezed diabase rocks along the east coast of Hudson bay, but careful analyses failed to show any contained gold, nickel or copper in a number of specimens from various localities on that coast, and it is highly probable that no important deposits will be found in the basic rocks of that side of the bay.
Small quantities of copper-pyrites were observed in the diabase schists of the south side of Hudson strait, but never in sufficient amounts to constitute mines of that mineral.
I was informed by Captain Adams, of the whaler Diana, that he had picked up specimens of copper ore lying loose on the surface a few miles in rear of Clyde river on the east coast of Baffin island.
Among the specimens brought home by Hall from Frobisher and Cyrus Field bays, in the southeast part of Baffin island, were bornite and pyrite, showing that copper ores also occur in that portion of the island.
Iron.—Mention has been made of the iron ores on the west shores of Ungava bay, on the north side of Payne river. The rocks in which these ores are found have been altered by the intrusion of granites. They now consist of quartzites, mica-hornblende schist and crystalline limestone, and are the metamorphic representatives of the unaltered iron-bearing rocks of the interior of Labrador peninsula and the east coast of Hudson bay. In localities where the rocks are unaltered the iron ores occur either as carbonates in a cherty rock, or as a mixture of magnetite and hematite intimately associated with chert and jasper. At Payne river the iron-bearing beds have a thickness of 420 feet. The upper 70 feet is a light-yellow, fine granular quartzite containing patches of ankerite and lime. Towards the top the rock shades to a dark bluish-gray, from the presence of large quantities of magnetite in small flattened grains, together with small scales of specular iron. These are usually mixed with quartz with evidence of foliation, and at other places are in large masses of nearly pure ore. Underlying these beds is 350 feet of dark-bluish slaty quartzite holding considerable magnetite and hematite, and shading upwards into a barren quartzite. Most of the ore of this locality would probably require separation and concentration from the admixed quartz before being of a grade sufficiently high for smelting. The position of the deposits on the west side of Ungava bay, where the tide rises and falls forty feet or more, is not very promising for shipping.
More attention has been given to the iron deposits of the east side of Hudson bay than to any other of the mineral deposits of the north. In 1877, Dr. Bell explored the east shore of Hudson bay as far north as Cape Dufferin, and in his report on this exploration called attention to the deposits of iron ore found in a bedded series of rocks, chiefly sandstones, cherts and dolomites. These rocks he found forming the islands along that coast from Cape Jones, at the mouth of James bay, to Cape Dufferin, some 300 miles farther north. A strip of the same rocks occupies the mainland from the vicinity of Great Whale river to beyond the head of Richmond gulf, a distance of 120 miles.
The iron ores of value were found to be confined to the Nastapoka chain of islands, which extend northward from Little Whale river for a distance of 100 miles.