You are browsing the archive for proterozoic Archives - AGU Blogosphere.
21 June 2022
Another example of overturned bedding
One of my favorite tricks is using bedding / cleavage intersections to identify tectonically inverted strata. On a field trip yesterday to check out soapstone quarries in the Albemarle/Nelson border region, I got to see this lovely example of Lynchburg Group metasediments that showcased a textbook example of the phenomenon: Bedding was initially horizontal, or close to it, and cleavage (formed under tectonic compression) initially vertical. Subsequent deformation rotated the …
22 May 2020
Friday fold: Anticline in Glacier National Park
Some web research led to a serendipitous discovery and further exploration. Wherever you’re sheltering in place, you don’t have a view that’s this grand. Slip away for a few moments to the high country of Montana’s Glacier National Park, where an anticline may be seen in the towering cliffs…
22 November 2019
Friday fold: Noonday Dolomite in Mosaic Canyon
Because I’m putting together a field course for spring break 2020 to Death Valley California, I was looking through old Death Valley photos this week, from the last time I went to that special place. It was seven years ago! How time flies… This one is in Mosaic Canyon, and was taken by my student Marcelo Arispe, a talented photographer as well as a talented geologist: By the standards of …