136 REGINALD A. DALY 
put them in his ‘‘ Black Shale” division of Michigan,* which C. 
Ey Wright has called the St. Clair Group.) ihe widemextent 
of these shales is further emphasized by their correlation with 
the important zone of the ‘“‘Huron Shale”’ in Ohio.3 
At the Ontario locality the rock is argillaceous throughout, 
of a dark ‘brownish-gray to black color, which is partly due to 
Fic. 1. General view of the shale at Kettle Point, showing jointing. Several 
‘concretions appear above the surface of the water. 
the strong impregnation of bituminous matter, so abundant as to 
make the rock inflammable. Fossils are not rare; indeed, there 
is a very striking exhibition of large specimens of Calamites 
enornatus, and of other plants, lying prostrate in the shale. In 
addition to the calcareous concretions there is a great abundance 
of concretions of iron pyrites, which are, however, always small, 
generally lenticular, with the greatest diameter under three 
“(Ojob Cling [Do Ofc 
2 Rep. Geol. Sur. Michigan, Vol. V, 1881-1893, Pt. II, p. 21 (ed. by Lane). 
3 NEWBERRY, Geology of Ohio, Vol. I, 1873, p. 154. 
