Ontario Geology

Ontario has a long and lively geological past that goes back to when the Earth was a very young planet. The first piece of the crust that is now Ontario made its appearance more than three billion years ago. Since then, the province has been shaped by the movement of the ever-shifting plates that cover the surface of the Earth.

Ontario is a showcase of geological processes caused by these shifting plates, including volcanism, earthquakes and mountain building. Huge sheets of creeping ice, tropical coral reefs and even salt water lagoons are all part of our province's past.

These exciting events are all recorded in the rocks of the province.

In ROCK ONtario, learn more about Ontario's rich and unique geology. This book, in PDF format (51 Mb), with many photographs and drawings, explains the development of Ontario's landforms through the ages. Subjects covered include plate tectonics, volcanoes, earthquakes, glaciation and the major geological areas of the province. It includes a description of the economic importance of geology, and tells how the minerals of the earth have contributed to the lifestyle we enjoy today.

For more detailed information on the geology of Ontario, visit the local geology descriptions provided by the Resident Geologist Program.