North Dakota’s Geological Legacy

Review: North Dakota’s Geological Legacy: Our Land and How It Formed, John P. Bluemle, 2016.

When I go to a new place or return from one, I like to pick up some geological books to explain what I saw.

So, before returning to my once and present home of North Dakota after many decades (though to opposite ends of the state), I read this.

Bluemle is the former state geologist of North Dakota and has admirably succeeded in explaining to the state’s residents, those passing through, and anyone else interested why North Dakota looks like it does.

The book has all the modern appurtenances you could ask for: maps, diagrams, geologic timetables, a glossary, appendixes, a bibliography for further reading, and clear color photos, most from the author’s collection.

Rather following the popular Roadside Geology format, he divides the state up into geologic zones though he doesn’t restrict himself to just what you can see from the road.

Since the only reading on North Dakota geology before now that I’d done was on uranium mining in the state (a subject somewhat obscured by national security concerns) before, I learned a lot.

Besides explaining the features of my boyhood home in the southwestern part – a section with the state’s greatest topographical relief, lots of erosion, and many fossil finds, I learned that the common perception of the Missouri River’s course being determined by the advancement of glaciers about 10,000 years isn’t exactly true. It’s a composite valley of pre-existing segments and one cuts during the last Ice Age.

I found the chapter on the Devils Lake Basin particularly interesting as it’s local. It explains the natural and extreme variability, even in historical times, for the lake. I was surprised, in relation to the hills around the southern edge of the lake, to hear them explained as “icethrust mountains”. Essentially, underground hydraulic pressure causes blow outs of soil and rock in front of an advancing glacier which then pushes them forward. They are not produced by ordinary crustal scraping by glaciers.

Another glacial feature new to me (granted, in my dabbling in college geology classes years ago, I didn’t take one on glaciology) are veblens, “ice volcanoes”, which, on the surface, produce features identical to kames. Again, they are produced by hydraulic pressure forcing subglacial rock and soil through the glacier and to its surface.

Bluemle covers the variety of wind, glacial, and water erosional features in North Dakota. Of course, there are the Badlands, but North Dakota even has sand dunes. He also explains why the flooding problems of the Red River, which flows north to Hudson Bay across the amazingly flat plain that is the bottom of Glacial Lake Agassiz, are only going to get worse since the land to the north is raising at a faster rate than the river valley to the south.

The many energy sources of North Dakota — including coal, oil, and wind are covered. (Yes, North Dakota really is as windy as the stereotype has it.) There is a clear explanation of how fracking works.

Bluemle spends a chapter on the influence of geology on the “human environment”. It covers some early settler accounts of the land. He also talks about the notion that ethnic groups settled where they did in North Dakota because the land reminded them of home. This is somewhat true regarding English, Scottish, German, and Russian immigrants. It also was a strategy that didn’t always lead to success.

And, speaking of trees, the Denbigh Experimental Forest is mentioned in passing. It’s the only part of a vast treebelt, proposed to be planted down the middle of Dust Bowl American in 1931, that was actually completed.

The somewhat amusing history of North Dakota gold rushes is covered. Of the four “discoveries” of gold in the state, three were the result of fraud or misidentification. The legitimate one was an uneconomical placer deposit probably from the Black Hills in South Dakota.

Definitely recommended for those interested in the geologic past of North Dakota.

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