eg ae 
oe Sa 
356 T. S. Hunt on the Geology of Southwestern Ontario. Be 
There exists in southwestern Ontario, along the River St 
Clair, an area of several hundred square miles underlaid by 
black shales, in the counties of Lambton and Kent, of which 
only the lower part belongs to the Hamilton group, Thew 
strata are exposed in very few localities, but the lower beds am 
seen in Warwick, where they were, many years since, examined 
by Mr, Hall, in company with Mr. Alexander Murray of the 
Geological Survey of Canada, and were by the former iden 
tified with the Genesee slate forming the summit of the Ham 
i 
ilton group. They are in this place, however, overlaid by more 
arenaceous beds, in which Prof. Hall at the same time detected 
the fish remains of the Portage formation. The thickness of 
these black strata, as appears from a boring in the immediate 
vicinity, is fifty feet, beneath which are met the gray Hamilton — 
shales. A similar section occurs at Cape Ipperwash or Kettle 
Point in Bosanquet, on Lake Huron, where bands of alter 
ting greenish and black arenaceous shales, holding Calamites,ar 
met with. These strata also were recognized by Mr. Hall, who 3 
examined them, as belonging to the Portage formation; and 
abound in the large spherical calcareous concretions which 
occur at the same horizon in New York. The entire thickness — 
of the black shales at this point has not been determi Lett 
in numerous borings throughout the region under notice, re 
are easily distinguished, both by color and hardness, from 
soft gray Hamilton shales which underlie them. At Coruna 
tee Sarnia, a thickness of not less than gs feet a hard black 
shales, interstratified toward the top with greenish sands) — 
were met with. In the northern part of Enniskillen, 2 
Wyoming, they are about fifty feet in thickness; at Al ‘ 
to be seventy-seven feet, while southward, along the ey 
Lake Erie, about sixty feet of the hard black slate over® 
Cy) strata, down to the summit of the ath: gray : ls 
whole thickness of the Portage ( ak 
