New Discoveries In South-Central Ontario

On this blog, I posted "The Toronto Story" about the natural history of the Toronto area. About 12,000 years ago, as the glaciers of the last ice age melted, the area became a network of mighty but temporary rivers that have shaped the land on which the city is built. I find autumn to be the best time for such studies because it is after the leaves have fallen but before the snow has arrived so that the contours of the ground are more easily visible.

But to the west, an even more vast network of temporary rivers to rival any seen in the world today had formed. The area drained by the three major drainage systems in the Toronto area, most notably that centered around the Don Valley, drained the high ground of upper central southern Ontario. This is the area centered around the city of Orangeville. The vast area of high ground to the south of that formed a separate drainage system.

In Brantford, There is a system of wide valleys around the downtown area that lead to a very wide valley now occupied by the Grand River. This river is but a trickle in comparison with the temporary rivers that were here as the glaciers melted and the waters drained away, leaving a permanent imprint on the ground.

Following East River Road from Paris toward Glen Morris, we find ourselves on the cusp of an escarpment with the river below. We can see by looking across how deep and wide a river once flowed here draining away glacial meltwater. On Route 24 approaching Cambridge, we are actually on the bottom of the former river. The downtown area of Cambridge, famous for the stone construction of many of it's buildings, is built on the former river bottom.

The remains of several more drainage rivers are nearby. North of Cambridge on Route 8, there is a massive dip in the road representing such a former drainage river. Another vast former river is now occupied by the Speed River. There is yet another former river now occupied by a river of about one percent of it's former volume just before reaching Kitchener.

The Kitchener-Waterloo area itself is crossed by many former drainage channels, just as the Toronto area is. On Route 7 from Kitchener to Guelph, we can see the same rolling countryside and former drainage channels indicating the presence of the former glacier that we can on the highway from Hamilton to Brantford.

In the city of Guelph, we can again see how vast former drainage rivers rivaling the Amazon or Mississippi Rivers are now occupied by rivers that are merely a trickle by comparison. Since Brantford is centrally located in the former drainage system that I have described, I will refer to this as the Brantford System.

This and the drainage systems centered around Toronto were not the only ones in southern Ontario. As I described in the posting "The Toronto Story", much meltwater drained away through what natural historians call the "Dundas River", this is the vast natural gap looking from Hamilton above the escarpment north over Dundas. This vast gap was not carved by flowing water from the last ice age.

The great volume of water, deflected by the Niagara Escarpment, that flowed through it carved out the low area that is now Hamilton Harbour/Burlington Bay. On Highway 403 north of Hamilton, we can see several large ravines from the north that were carved by waters from the melting glacier flowing toward this area.

The waters from the Brantford System ultimately ended up where Long Point Bay on Lake Erie is now located. In satellite imagery on http://www.maps.google.com/, we can see vast systems of gulleys in the land around Inner Bay at Long Point Bay. Note the resemblance between Inner Bay and Hamilton Harbour.

There is another side to this vast glacial drainage system, the flow of meltwater from the London area that also emptied into the lake at Long Point. The long peninsula of land here known as Long Point that extends about forty percent of the way across Lake Erie is the soil that settled to the bottom after being swept away by the fast-flowing waters of 12,000 years ago.

Long Point extends so far out into Lake Erie that from Chautauqua County, NY on the American side, the mainland Canadian shore is too far away to be visible but the Long Point peninsula can be seen. This peninsula, like any delta, formed because dirt was being unloaded too fast for it to dissipate in Lake Erie.

We see on a map how the Toronto Islands and Presque Isle Park in Erie, Pennsylvania formed in the same way. The fact that there is no such delta at Hamilton shows that the Dundas River was pre-existant and was not carved by water from the last ice age. It is also clear that, on a large scale, water from melting glaciers tends to flow southward but that may not be true on a smaller scale.