Vermonters love it when the Canadian dollar is down; they flock north to Montreal. I love the trip for the fascinating geology: evidence of volcanoes, plate movements, glaciers, erosion. We’re surrounded by it all the way.
Southeast of Montpelier, where we start, are the Barre granite quarries, operating in a pluton, an upwelling of magma that penetrated an overlying formation about 400 million years ago. Merging onto I-89, we leave that bedrock for a band of an even older, Ordovician bedrock laid down about 460 million years ago. Fair Haven High School’s athletic teams, the Slaters, celebrate that era’s impact on Vermont history.
I-89 follows the Winooski River to Richmond. Probably few of us appreciate the convenience of the water-level gap through the Green Mountains created by the Winooski, which existed before the mountains, and eroded its valley downward as fast as they rose beneath it.
After the band of Ordovician bedrock, we cross still more ancient Cambrian formations. These rocks record the first flowering of life on earth. Splitting layers of Cambrian sediments as a boy, I felt the beginning of a romance with the earth and the tiny fossils I was exposing to daylight after half a billion years of waiting.
The Vermont hills fall away on both sides north of Burlington on the eastern shore of a vanished postglacial arm of the ocean. Past the border station, the highway, like a river’s mouth, debouches onto the St. Lawrence River plain: glacial till and outwash flat and featureless as Kansas. It’s covered with French-Canadian farms and studded with villages named for saints. Google Earth reveals a 17th-century European roture pattern: long, narrow fields laid out centuries ago by French seigneurs. I begin to convert speed-limits to miles-per-hour, multiplying by six.
Just south of Montreal, steep-sided monoliths pop up from the flat plain. They’re the Monteregian Hills, formed about 125 million years ago, when a “hot spot,” like the one under Yellowstone, intruded magma into softer overlying rocks. That still-active hot spot is now out in the North Atlantic, but millions of years of erosion in Quebec have left its monuments protruding from the flat plain. One of them, Mont-St-Hilaire, is reputed to be the site of UFO sightings and visitations by extraterrestrial beings.
Then suddenly, the Champlain Bridge lifts us high above the St. Lawrence, and we’re in the maze of Montreal, surrounded by more marvels – but these by human engineers.
This is Willem Lange in Montpelier, and I gotta get back to work.