Homer Watson Park geology

Saturday, December 24, 2011

What on Earth: Volume 7 2011

Kitchener: The Homer Watson Park section

P. F. Karrow

On the west bank of the Grand River, at Homer Watson Park, is an exposure of the subsurface materials which reveals something of the geological history of the Kitchener area. The exposure was created by river bank erosion by the Grand River. From time to time the exposure is covered by slumped material and vegetation, but this varies with river flooding and weather conditions.

Homer Watson Park exposure diagram showing the different layes of earth

The oldest deposit is at the bottom, near the level of the Grand River. It consists of a hard mixture of sand and silt with many stones deposited by glacial ice and called the Catfish Creek Till. It was laid down by the thickest ice to cover this area about 18,000 years ago. At that time, the glacier extended south into the United States as far as the Ohio River.
Above that till is some layered clay deposited in a glacial lake which occupied the Grand Valley. The glacier had melted back, but a lake had formed here. Into the lake, the glacier advanced again, this time ploughing up the lake clay to form a clayey till we call the Maryhill Till. This ice advance only extended into the western part of the Waterloo Region where it fluctuated for a few centuries. Meltwater from the ice laid down large masses of sand and gravel to form the Waterloo moraine. During ice retreat glacial lakes again deposited layered clay, and meltwater streamed formed the outwash deposits near the top of the cliff.
The final ice advance formed the Port Stanley Till and reached only part way into Kitchener before melting away again about 13,500 years ago. During this time, meltwaters formed the large gravel terraces along the Grand Valley; as the load of sand and gravel in the meltwaters lessened, the river cut down, becoming a slow-moving meandering stream with a steel cut-bank here on the west side which reveals the glacial history.
Examining many of these exposures allows us to build up the geological history of the district.