Toronto: Niagara Escarpment (Part 2)

Tropical vacation anyone?

During the Silurian Period, rising seas flooded much of the continent. At that time the GTA was south of the equator and the warm shallow seas were inhabited by an
abundance of marine invertebrates as depicted in the reconstruction below. Remains of these organisms are preserved as fossils in the rocks that form the Niagara Escarpment.

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Sapping process

Since the tropical seas disappeared millions of years ago, exposure to the elements has caused weathering and removal of the softer underlying shale, leaving a steep dolostone cap. This weathering process, called sapping, continues today.

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ne - fig7The Niagara Escarpment provides habitat for many unusual species including 1000 year old Eastern white cedars, the oldest living trees in eastern North America.


Grey cliffs of the escarpment are exposed within a forested strip. Below the cliffs, a golf course shows one of the recreational uses of this area. Above the
cliffs, dolostone is being extracted for construction.

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