Map of French Québec City's fortifications on bedrock relief (North is conveniently to the bottom right)
Québec City sits between the Laurentian highlands of the southeastern Grenville Province of the Canadian Shield and the Appalachian Mountains that were formed during the Taconic and Acadian orogenies. Bedrock here is the Upper Ordovician Utica shale that “overlies the predominantly shallow marine carbonate facies of the Cambrian-Ordovician St. Lawrence Platform” (or St. Lawrence lowlands).The adjacent St. Lawrence River, which I gather formed post-Pleistocene glaciation by cutting into the relatively less-resistant sedimentary rocks sandwiched between the Laurentians and the Appalachians, is part of the Great Lakes – St. Lawrence Seaway system.
As a sign by one of the many higher-up river outlooks explains, the land beneath Quebec City was not chosen by the French because of the overwhelming tectonics over an equally stupefying period of time that created it but purely for defense strategic reasons. To each their own time scale.
In a time-traveling nutshell: Canadian Shield forms the core of the North American continent –> happy passive margin forms with the buildup of a carbonate platform and the transgression of the sea –> BAM BAM Taconic and Acadian continental collision events creating the Appalachian mountains –> some quiet time as the Atlantic Ocean forms to the east –> glaciation from the north –> glacial retreat –> uplifted Québec City and associated river –> some French dude named Samuel de Champlain surveys the Great Lakes – St. Lawrence area, claims the high cape of Québec City and territory all the way from north of Minnesota down to and including Louisiana for New France in 1608 and his people put up a bunch of ramparts against, well, everyone –> the Brits take over in 1763 –> Canada forms in 1868 and tells everyone to sod off in exchange for putting limey monarchs on its currency –> Canadian geologists find economic natural gas in the Utica shale. (Someone call They Might Be Giants and set this to music.)
Related reading:
OMG, that is so sexy. I love it when you write like this. You’re such a rock star.
Um, thanks, I think. (You’re kidding, right? I don’t think I’ve ever heard you use OMG before.)
Yes, it was meant to convey internet delight; I am genuinely loving this post.
Thanks, I really appreciate it! Definitely no Simon Winchester or John McPhee here, but I have a few more geology-history posts. Once I dig out my old geology notes and drawings from undergrad and grad school, I’d really like to work on a multi-part piece called Acadia – all the way from the birth of the European continent to the Gulf of Mexico oil spill. Geology really helps you understand life as less a series of events and more a continuum.
This was great. I’ll be there for more romantic reasons this month (my 10 year anniv!), but I’m reading up on it before I go. See how far I have to run for cooler weather? That’s what I get for getting married in Nola in *August*. Hope you’re doing well. Will you be at RT6 this year?
Thanks, girl. I think you guys will like it. Very romantic and lots to see, learn, photograph and wander through. We almost got married in September but Katrina too care of that. Highly recommend January for weddings.
Hope thigs are good for you, too. As for RT6, quite likely.