Whiteaves — Trenton, rocks at Ungava. 433 



Akt. XLYII. — Recent discovery of rocks of the age of the 

 Trenton formation at Akpatok Island, Ungava -Bay, 

 Ungava; by J. F. Whiteaves. 



While accompanying the Hudson Bay expedition despatched 

 by the Canadian government in 1897, in the sealing steamer 

 "Diana," Dr. R. Bell, of the Geological Surveyor* Canada, 

 spent the 13th of September on Akpatok Island, on his way 

 from Ashe Inlet to Fort Chimo. In a preliminary report on 

 his explorations for that year,* Dr. Bell says : " The portion of 

 the island which I saw (from the northern end to the middle 

 of the east side) consists of unaltered gray limestone in hori- 

 zontal beds, and it presents a perpendicular wall 400 or 500 

 feet high all along." " This sea-wall is clean-cut and the beds 

 appear thick and solid, but wherever their edges have been 

 long exposed to the weather, or in the hill-sides and ravines of 

 the interior, they split up into thinner layers." " Some frag- 

 ments observed in one place had the appearance of lithographic 

 stone." " I was enabled to land opposite the place where the 

 Diana anchored, as already mentioned, about the middle of 

 the eastern side, and I improved the opportunity to collect 

 fossils, which, however, were not abundant." " Those obtained 

 indicate the Hudson River formation." 



When this last sentence was written, the specimens that it 

 refers to had not been unpacked. Since the publication of the 

 Report from which it and the four preceding sentences are 

 quoted (in May, 1898), these fossils have been examined by the 

 writer, and it at once became obvious, first, that they indicate a 

 little lower geological horizon than the Hudson River forma- 

 tion, viz., that of the Trenton limestone ; and, secondly, that 

 they are remarkably similar to the fossils of the Trenton 

 formation of the Red River valley in Manitoba. The collec- 

 tion consists of fifteen species, but two of these are imper- 

 fect casts of the interior of shells of gasteropoda, that can 

 only be determined generically. Of the thirteen that remain 

 eleven had previously been found in the Manitoba Trenton, 

 and nine are species that are common at East Selkirk and 

 Lower Fort Garry. The two fossils of which by far the most 

 specimens were collected are Strejptelasma robustum and Cyrto- 

 ceras Manitobense. The former is a rather large rugose coral, 

 the types of which are from the Red River valley in Manitoba. 



The following is a list of the species represented in the col- 

 lection, as far as they can be determined. 



* Summary Report of the Geological Survey of Canada for 1897, page 82. 



