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.