GEOLOGY OF THE TORONTO REGION
sheets during the Glacial Period. The palaeontologist will find a variety of Ordovician, Silurian and Devonian fossils in the bed rocks of the region, the Pleistocene geologist may study a complex and important series of later deposits, the physiographer will observe a more interesting set of surface phenomena than could have been expected in a district without mountains, and the dynamic geologist may study the effects of glacier ice, of rivers, waterfalls and waves, and also see the evidences of important changes of level within post-glacial ages.
Within one hundred miles of Toronto the following geological formations are displayed :
Recent Shore cliffs and wave-built bars. Pleistocene . . Glacial, Interglacial and Post-glacial beds.
Devonian—Onondaga and Hamilton beds.
Silurian—Cataract, Medina, Clinton, Niagara and Guelph Palaeozoic . . beds.
Ordovician—Trenton limestone, Utica and Collingwood shale, Lorraine shale and Queenston shale.
Archaean . . . Granites, gneisses, greenstones and greenschists.
The vast interval between the lower part of the Archaean and the Palaeozoic is unfilled, and the 53