Introduction

Overview of the
Humber River

Global and Continental Glaciation

Land Form Development in North America

Geological History
of the Great Lakes

Development of the
Oak Ridges Moraine

Geology of the
Humber River Watershed

Ecology

Early Inhabitants

Maps of the
Humber River Watershed

Photo Gallery Humber River Watershed

Pleistocene Geology of the Humber River

Part IX - Recent Glaciation

The remnants of two main periods of recent glaciation are present in Southern Ontario and the ORM area. Relatively few sediments of the Ilinoian Glaciation and Sangamon Interglacial periods remain, thus the stratigraphic column is dominated by sediments of the more recent Wisconsinan period. The sediments of the Ilinoian glaciation period are limited to the York Till deposits most commonly found in the deeper bedrock valley systems, particularly in the south. (approximately 135,000 years before present (BP))

The last major ice advance, the Late Wisconsinan, (25,000 to 12,000 years BP) was from the northeast and along the axis of the Great Lake basins. During this interval, the Laurentide Ice Sheet deposited a thick widespread till sheet or amalgamated sheets generally referred to in the Toronto area as the Newmarket Till (also referred to as the Northern Till). This till overlies thick lower deposits and both sequences continue under the Oak Ridges Moraine.

This regional till sheet is variable in thickness (Sharpe et al., 2002) and has been eroded in many locations by meltwater to form a regional unconformity consisting mainly of drumlinized till and a network of channels (Barnett, 1990).


This till overlies thick lower deposits and both sequences continue under the ORM. This regional till sheet is variable in thickness (Sharpe et al., 2002b) and has been eroded in many locations by meltwater to form a regional unconformity consisting mainly of drumlinized till and a network of channels (Barnett, 1990).

The ORM sediments rest on the eroded terrain between the Simcoe Lobe and the Ontario Lobe and was formed approximately 12,000-13,000 BP (Gwyn and Cowan, 1978).