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Showing posts from March, 2020

Structural Geology Trip to the Ouachita Mountains

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People looking at folds. Faces obscured to protect identities. ¡Mas folding!. Action shot of man pointing at a fold Normal fault in sandstones and shales Recently, I got to join a field trip to the Ouachita Mountains to discuss a spectacular structural event that took place in the Late Paleozoic. The strata of the Ouachita Mountains are dominantly sandstone and shale beds from the Cambrian to the Pennsylvanian that were deposited in an offshore, deep water environment somewhat similar to the deep water regime of the Gulf of Mexico. Beginning in the Mississippian Subperiod, a compressional event initiated as proto-North America collided with a small land mass (volcanic arc) to the south creating the Ouachita Mountains, a

Maps Below Our Feet

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About four years ago I ran across a website called Macrostrat.org , a website that started from the University of Wisconsin to compile stratigraphic data into a searchable database. While browsing their site, I saw the most beautiful geologic map. Don't get me wrong, there are great geologic maps that have been published, but this one struck a chord with me. Painted in the standard geologic colors, but with an earthy hue, was the surficial geology of the continental United States, northern Mexico, southern Canada, and the oceans. No borders between countries or states were visible, except for a couple of inexplicable odd lines along Michigan and Mexico that just happened to render. It's just geology. The zoom setting I had it on restricted the details to what are visble on a national scale. Not too generalized; not too specific. It looked as if it were a piece of abstract art with hints of Jackson Pollock evident in the Basin and Range province. I immediately thought tha