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20 February 2010
GSW spring field trip
A few photos from last May’s spring field trip with the Geological Society of Washington… Here’s the group at Chain Bridge Flats (far westernmost-Washington, D.C.), looked at the metamorphic rocks there — a metagraywacke melange known as the Sykesville Formation. Another group shot, with field trip leaders Tony (khaki shirt) and Gary (red jacket) Fleming in the foreground: Euhedral metamorphic pyrite crystals (porphyroblasts): An elusive bedding plane in the Sykesville …