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You are browsing the archive for 2015 April.

30 April 2015

Early Paleozoic fossils in Nealmont Formation, Germany Valley, West Virginia

Looking at Ordovician carbonates in Germany Valley, West Virginia, a few weeks ago on Rick Diecchio’s GMU sedimentology and stratigraphy course field trip: Lots and lots of brachiopods… Crinoid columnals mized with brachiopods: A set of coarsely-infilled trace fossils: Crinoid stem: Nice strophomenid brachiopod: Bryozoan? Receptaculid?

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28 April 2015

Epidotized tuff, Tucson Mountains, Arizona

I was in Tucson this past weekend for a book project meeting, and my editor and coauthor and I took a hike on Sunday morning in the Tucson Mountains to Wasson Peak. Not far from the summit, we saw an epidotized tuff, where the fiamme and pumice blobs had undergone reactions to produce pods of epidote, giving the rock a look like a sick dalmatian: This is a cool rock …

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24 April 2015

Friday fold: Bloomsburg Formation at lime kilns on C&O Canal

Milepost 127.4 (High, 2001) on the C&O Canal: …Cool if you’re into history. …Cool if you’re into economic geology. …Cool if you’re into Friday folds!   Reader Eric Fulmer sent me this photo (along w/ two others you’ll see in weeks to come). Thanks, Eric!

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17 April 2015

Fault breccia in Beekmantown limestone

Here’s another sight at the Eocene dikes site in Bluegrass Valley, Virginia, mentioned yesterday: That’s a gorgeous fault breccia, emplaced parallel to bedding, and parallel to the felsic dike (which can be found a few feet to the west / right of these photos): It was very poorly lithified, shockingly crumbly to the touch, considering the big slab of rock downhill (to the right) of it. Here’s a link to …

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16 April 2015

Eocene dike and sill in Ordovician limestone

A virtual field trip to a quarry in far western Virginia, showing anomalous igneous intrusions (a dike and a sill) of Eocene age cross-cutting early Paleozoic carbonates.

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15 April 2015

Spring time

This past weekend, I had a chance to visit Bath, Highland, and Alleghany Counties, Virginia, three amazingly beautiful places I had never before seen. I was tagging along on my colleague Rick Diecchio’s annual sedimentology & stratigraphy field trip for George Mason University. I was eager to learn from some awesome field sites from him in the year before he retires. We saw some terrific sedimentary rocks, of which more …

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14 April 2015

Compare and contrast: Two Chesapectens

Two new GIGAmacro images of fossil scallops from Virginia’s Coastal Plain – Chesapecten nefrens: link Chesapecten jeffersonius: link My vision is to get the opposite side of each of these samples as well as a half-dozen other species in this genus, perhaps even multiple individual specimens of each species, to allow students to do a lab where they plot morphological changes over geologic time as an example of what the …

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6 April 2015

Exploring Mahantango Zoophycos traces in GigaPan

Recently, I posted about an excellent road cut in Fort Valley showing well-developed 10 cm+ Zoophycos trace fossils. Presented here are three new GigaPan images (two outcrop; one macro) of Zoophycos from the Devonian-aged Mahantango Formation: link link link These images are part of a new “virtual field trip” that I organized to supplement my historical geology field trip to examine the geologic history of the Massanutten Synclinorium. The link …

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