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18 October 2017
The 2017 Virginia Geological Field Conference had a heavy arkose infusion. Meet some of these feldspar-rich Neoproterozoic sediments of the Lynchburg Group.
11 August 2017
For the Friday fold, Callan digs out images of Eagle Rock, Virginia, well aged in his digital archive for a decade!
15 April 2017
My son and I hiked Compton Peak in Shenandoah National Park this morning, and saw these two lovely examples of xenoliths. The example above is small, but it shows clearly the difference between the coarse, felsic basement rock (Mesoproterozoic granitoid, comprising the xenolith) and the surrounding fine-grained dark green metabasalt of the Catoctin Formation (Neoproterozoic). Here’s another, bigger example: These two Blue Ridge examples both illustrate the principle of relative …
27 March 2017
Explore a dozen photos highlighting the structural geology of an outcrop of limestone and shale near Lexington, Virginia. Cleavage refraction, overturned beds, boudinage, folds, and even a small fossil – we’ve got something for everyone. Bring the whole family!
27 February 2017
A new outcrop in Fort Valley shows Devonian fossil-rich mudrocks overprinted by a tectonic cleavage imparted during Pangaea’s birth throes.
25 February 2017
Some enormous concretions are encountered in a shale quarry in the central Fort Valley. Concretions like these are typical of the Devonian-aged Millboro Formation.
13 February 2017
A new edition of “science and nature question and answer.” This week: why Massanutten Mountain isn’t longer, and why you’re never going to walk on the Sun.
31 December 2016
Eastern bluebird (and its lunch, a camel cricket) Purple finch (male) At New Year’s, I post my “yard list” here. It’s a list of all the bird species observed in my yard in Fort Valley, Virginia, over the course of the previous calendar year. I have been posting this list every year since I moved here: 2012 (39 species) 2013 (52 species) 2014 (58 species) 2015 (65 species) Yellow-billed cuckoo …
8 December 2016
Two very different samples tell stories that are full of holes. What’s going on with this weathered sandstone? What’s going on with this fossil scallop shell?
29 October 2016
In Shenandoah National Park, astride Virginia’s Blue Ridge, feeder dikes of Catoctin Formation (meta-)basalt cut across the Grenvillian-aged granitoid basement. Due to their mafic composition and columnar jointing, these feeder dikes generally weather more rapidly than their host rocks. I led a field trip in the park on Thursday for my son’s school, and my student Marissa was there the weekend prior, checking out the autumn leaves and geology with …