Webinar - Ancient Seas, Glaciers and Waterfalls: The Geologic History of the Niagara Escarpment

(Recording from May 28, 2020, Webinar for BTC Members)
Presented by: Dr. Carolyn Eyles and Rebecca Lee, School of Geography & Earth Sciences, McMaster University.
In this webinar we explore the fascinating geological history of the Niagara Escarpment. The rocks we see exposed along the Escarpment today were deposited in an ancient tropical sea that covered large parts of Ontario between 400 and 450 million years ago. The sea teemed with marine life and these ancient animals are now preserved as fossils within the limestones, dolostones and shales that accumulated on the sea floor. These ancient sedimentary rocks have been eroded over time as glaciers and rivers repeatedly scoured the landscape; the steep Escarpment face we see today continues to evolve as waterfalls cascade over its edge.

[@annettesandberg8879]

Excellent presentation!!

[@hojoinhisarcher]

As a boy in Toronto, my home park was the Humber river valley from Kipling thru to Islington.Massive blocks of limestone deep beds of shales had been exposed as Hazel the previous fall had ripped a vertical 40' wall of the west bank open and spilled a fan of peculiar fossil debris over the plain of the bank opposite for hundreds of feet.I had no idea what any of this was until your talk.Thanks.

[@palvanga]

I live right by lake school. This video was amazing. Very informative

[@khewitt2873]

Very clear and concise. I learned so much! Thank you.

[@valoriel4464]

Fascinating content.
Thank you

[@myrandomnadventures]

Very informative video!! As a Niagara Falls resident I grew up exploring the gorge and whirlpool and always wondered about the layers in the rock and how they formed. I know on my next hike down there I'll now be looking at those rocks in a whole new way. I never thought to look out for fossils down there either, cool. It's amazing how the retreating glaciers created the landscape we see around us now with all that water. My only question is where did all that heat come from to do all that melting?

[@moviezaftermidnight6348]

shallow seaa means if it was that high at one time, it will be again.. There is sand in Upper beaches in Toronto, almost 100ft altitude increase from shores of Lake Ontario..
uplifting can stop with development of glacier.. nice at road salt

[@brianjacob8728]

younger dryas impacts? the elephant in the room.

[@user-df5zm4dk1c]

Are you referring to the theory of extraterrestrial impactors striking the surface of the Laurentian ice sheet? Randall Carlson covers the evidence for and against pretty well. I’m curious about this too. Specifically what types and sizes of meteoroids would be involved, and where are the associated meteorites?

[@brianjacob8728]

@@user-df5zm4dk1c yes. actually, there were impacts world wide, mostly in the northern hemisphere, but south america was impacted also. Africa and Australia seem to be the regions least involved.
The rest of your questions remain unanswered, tho there was an iron metereorite that impacted in western canada that ended up in west central oregon. But I wouldn't rule out a solar mass ejection playing a role as well, given the amount and rapidity of the ice melt in question.