ABSTRACT: Regional Correlation of Ordovician Stratigraphy North of Lake Ontario, Ontario, Canada

ROBERT BLAIR and SEAN MCFARLAND , Golder Associates Ltd, Mississauga, ON, Canada

A regional subsurface correlation of Ordovician strata north of Lake Ontario has been carried out by Golder Associates Ltd. based on drilling completed for the power generation, aggregate and cement industries and records of oil and gas exploration wells. The correlation has been developed on the basis of logging of rock core from boreholes drilled through the Ordovician strata completed in the Precambrian basement, coupled with geophysical logging of the open boreholes. The regional correlation has involved development of three regional cross sections. One of these is along the north shore of Lake Ontario through deep boreholes completed by Golder Associates and exploration wells for the oil and gas industry and indicates lateral continuity of the formations and units across the basin. A second cross section extends from Lake Ontario north into the Lake Simcoe area where the Bobcaygeon and Verulam Formations are exposed at the surface, while the third section extends into the Shelburne area where the Ordovician strata is overlain by Silurian age Amabel Formation. Natural gas was encountered in some of the boreholes along the north shore of Lake Ontario within the Verulam and Bobcaygeon Formations and the contact of the Shadow Lake Formation and the Precambrian basement, although their economic potential has not been assessed. The regional correlation of Ordovician stratigraphy is of importance for the oil and gas, and aggregate and cement industries.

Search and Discovery Article #90907©2000 AAPG Eastern Section Meeting, London, Ontario, Canada