A considerable collection of fossils was brought home from the beds forming the southern half of the west coast of the island. These have been examined by Dr. Ami and Mr. Lambe, whose determinations will be found in Appendix iv. The fossils show that the rocks contain a fauna closely resembling that of the Lake Winnipeg basin, and extend over a period from the Galena-Trenton to the Guelph and Niagara, or from the upper part of the Cambro-Silurian to high up in the Silurian.
Soundings taken on the even bottom of Fisher strait show that the limestones extend without a break to Coats island (to the southward of Southampton), where they occupy all of its surface except the portion at the east end of the island where the Archæan ridge crosses it. A few fossils from Mansfield island show that it also is formed of limestones of these horizons.
At Cape Chidley a collection of fossils from loose pieces of limestone corresponds with fossils from Akpatok island, and the direction of ice movement out of Hudson strait leaves little doubt that the loose limestone of Chidley came from that island. These fossils show a slightly wider range in age than the rocks of Southampton do; they extend from the Lower Galena-Trenton to the Lower Heidelberg.
West Coast of Hudson Bay.
The wide fringe of limestones which is found along the west shores of Hudson bay to the southward of Churchill do not come within the limits of this report. To the northward only Archæan rocks are found along the mainland until the northern half of Melville peninsula is reached, where Parry describes a wide area of sandstone, probably the base of the Cambro-Silurian, as separating the highlands of the interior from the western shores of the northern part of Fox channel. These rocks are continued on the north side of Fury and Hecla strait, where they are found on the west side of Baffin island fronting on Prince Regent inlet.
Islands of Group II.
The only known occurrence of Silurian limestone on the eastern side of Baffin island is at Silliman’s Fossil Mount, near the head of Frobisher bay, where the limestone forms a hill 1,000 yards long and 350 feet high, resting almost flat upon the crystalline rocks. Seventy-two species were identified by Schuchert from fossils brought back from this locality; he refers them all to the Galena-Trenton.
Little is known of the limestone about the great lakes, Nettilling and Amadjuak, in the interior of Baffin, beyond the meagre observations of Boas, who briefly refers to the limestone about Nettilling and along the east side of Fox channel. These limestones are probably an eastern extension of the Southampton area, but their exact age will remain unknown until fossils have been collected from them.
On the east side of Prince Regent inlet the rocks composing the high cliffs of Baffin island are the basal sandstone and shale overlaid by limestones, which in places are interbedded with beds of gypsum. These high cliffs of limestone extend eastward along the south shore of Lancaster sound to the mouth of Admiralty inlet, when they give place to the Archæan crystalline rocks, which rise slowly to the eastward from beneath the level of the sea, in a manner similar to that already described, on the north side of Lancaster sound.