HUEONIAN EOCKS OF LAKE SUPERIOR. 71 



to 800 feet. Here, resting upon it, are to be seen only the trappean beds of the Keweenian 

 group, with a low dip east-south-eastward. In the next basin, five to seven miles from 

 the bay, the indurated marls and sandstone beds of the Keweenian group appear under 

 the trappean beds. 



Low down, within two or three miles of the bay and about three to four miles south 

 of "Wolf Eiver, I saw black-looking flat slates, which I think must be Animikie. I have 

 not been in that locality for years and would not be sure of this point. If Animikie, it 

 would be interesting to trace out the contact with the Keweenian beds. "Within these 

 basins and all around this locality, the folded schists, the granites and the gneisses stand 

 vertically or nearly so, and must have been eroded and planed down to a great depth 

 before the deposition of the overlying fiat beds, whether the verticality of the strata was 

 caused by folding or by faulting. 



Again, in McTavish Township in the vicinity of Enterprise Mine, the old rock 

 foundation, in the form of islands, protrudes through the flat-lying sandstones and marls 

 of the Keweenian group. In similar manner the green Huroniau strata protrude through 

 the flat-lying Animikie beds in the vicinity of Blende Lake, near the foot of Thunder Bay, 

 and at other places. 



The 3 A Silver Mine in McGregor Township, is in the Huronian greenstone-schists 

 formation, and the Silver Harbour Mine in the flat Animikie slates, both locations adjoining. 

 The line of contact of the two formations is covered, but on approaching it, they show 

 no change in their regular dips, which are almost at right angles to one another. Again 

 I could see no tendency to a transition in character — the one showing its Animikie pecu- 

 liarities and the other the Huroniau aspect, as distinctly as when these rocks occur at great 

 distances apart. On the shore of Thunder Bay to the west, between Silver Harbour and 

 "Wild Goose Point, I remember distinctly seeing undisturbed patches of the original 

 smooth surface or floor, upon which the Animikie beds were deposited over the nearly 

 vertical Huronian green chloritic and dioritic schists. Some flat Animikie slate was 

 still fast in situ at these places. The lower layer consisted of a thin indurated matrix, 

 thickly packed with small pebbles, mostly of white quartz. The vertical schists referred 

 to strike into the bay directly under the Animikie beds. Again further west along the 

 line of contact of the two formations about two miles and a half to the north-west of 

 T Harbour, on Location No. 2, the flat Animikie slates are seen in place, filling inden- 

 tures in the highly inclined green Huronian strata. 



At the Duncan (formerly called the Shuniah) Mine two or three miles north-east of 

 Port Arthur, the rocks at the surface consist of the flat-lying, unaltered, Animikie black 

 slates, etc., with the nearly vertical Huronian strata underlying them at a depth of about 

 five hundred feet, while the surface-contact of the two formations lies to the north about 

 one mile from the works. The shaft-sinking, and the deep borings made at this mine 

 with the diamond drill, actually aflbrded direct proof that the horizontal and unaltered 

 shales, etc., rest immediately on Huronian syenite and on the upturned and denuded 

 edges of the crystalline schists of this series. 



The folded schists with associated granites and gneisses are highly inclined or ver- 

 tical, in the vicinity of Thunder Bay, as is the case with them generally ; w^hile the 

 Animikie beds, on the north shore, are, with rare exceptions, flat or slightly inclined. 

 We find patches or outliers of the Animikie beds in their usual flat position, resting on 



