GMS Field Trip

GMS Field Trip
Epidote, Grossular Garnet, Scolecite, Geology
in Georgia
Saturday, December 7, 2019

Geology and mineralogy abound at this quarry, so we were fortunate to get to spend a beautiful Saturday there. When magma rises through the earth’s crust and bits of country rock fall into the magma, rocks that maintain their composition and are not completely dispersed into the magma are called xenoliths. The area of the quarry we visit has large xenoliths of metamorphic rock in the granite. The xenoliths there contain a lot of pistachio green epidote and orangey red grossular garnet. They are also the source of many microminerals. On this trip I saw several specimens of scolecite and at least three unidentified minerals. Joe McKinney found crystals that are clear/white and have a tabular crystal structure. David Bruce broke open a boulder and gave Charles a sample that has epidote, garnet, pyrite, scolecite, and another unidentified mineral that is cubic, clear/white, and has striations with a white overgrowth. While examining that specimen I saw some deep green crystals too, probably diopside. Plus, there is another mineral with dark cylindrical crystals attached to the spray of scolecite crystals! William and Frances Fleck found a plate of quartz points as well as a specimen with large epidote crystals. Small pieces with epidote and garnet were everywhere, so we collected lots of those for juniors.

It was a very productive day at the quarry with many nice micromineral specimens and xenolith filled boulders finding new homes. I even got two samples of sand! Many thanks to the quarry people who welcomed us warmly and kept us safe. Thank you to field trip attendees who helped each other and shared specimens. And thanks to Charles Carter for setting up this great trip!

Lori Carter
On behalf of Charles Carter, GMS Field Trip Chair
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