All they found of him was a muddy set of prison clothes, a bar of soap, and an old rock hammer, damn near worn down to the nub. I remember thinking it would take a man six hundred years to tunnel through the wall with it. Old Andy did it in less than twenty. Oh, Andy loved geology. I imagine it appealed to his meticulous nature. An ice age here, million years of mountain building there. Geology is the study of pressure and time. That's all it takes really, pressure, and time.Time and pressure is the story of Glacier National Park. There are the glaciers, of course, for a while more, maybe twenty years, but there are also the rocks, and there are the mountains too. Glacier National Park in northern Montana has some of the most incredible scenery of any national park but it has a fascinating geological story as well.
I mentioned at the beginning of this mini-blog series that an overall theme was convergence, due to the influence of the subduction zone that has existed off the west coast of the U.S. for several hundred million years. It is not unusual to see the effects of subduction for eighty miles or so inland where stratovolcanoes like those of the Cascades develop. But we had been traveling east now for more than five hundred miles. How could a subduction zone influence the crust so far inland?
We bravely set foot into the wild frontier of Canada, and also wondered who has the job of keeping that line clear through the miles of forest. It was one of the busiest border crossings I've ever seen, as there was at least one motorcycle that came through while we hung around.
I wish I had a chalkboard to illustrate, but the wikipedia diagram will have to suffice in this instance!
|From Wikipedia (http://en.wikipedia.org/wiki/File:Thrust_system_en.jpg)|
they shouldn't be allowed to fly airplanes).
|Picture by Susan Hayes|
One of the most vivid layers was the dark red Grinnell Formation. There was no oxygen in the Earth's original atmosphere, but when photosynthesis evolved, oxygen was released. It immediately reacted with iron in the sediments, and the world turned rusty red. Although the rocks are from an alien time in our own history, they still contain recognizable features like the exquisitely preserved mudcracks seen below.
Time and pressure....