Southwestern Virginia Case Study
A1 B2 Schist
Elizabeth A. Johnson
Outcrop and Hand Sample Photos and Videos
Click on the image to enlarge.
This outcrop is on a busy road. The schist is coated in a dark later of pollution from car exhaust, making it look black on the outcrop. A fresh surface reveals a shiny silver schist.
The staurolite is the large orange porphyroblasts in the hand sample. Dark minerals are biotite. Much of the rock is muscovite, some quartz, a little plagioclase. Kyanite is rumored to be present. Tiny garnets are hardly visible in hand sample.
Thin Section Photos and Videos
Click on the image to make it larger. 1st = plane polarized light; 2nd = cross-polarized light.
Biotite (brown in ppl) and staurolite (yellow in ppl, top left) porphyroblasts. High-relief euhedral mineral is garnet. Qtz and muscovite are also present.
Staurolite (yellow), qtz, garnet (isotropic, high relief), a little muscovite.
Close up of garnets (+ stl, qtz, musc). Note the pattern of inclusions in the garnet in ppl.
Entire thin section scan. 1st = ppl; 2nd = xpl. Click on the image to make it larger.
This thin section is super interesting for thinking about deformation and metamorphic events.
- A1 B2 4x ppl no2
- A1 B2 4x xpl no2
- A1 B2 4x ppl no4
- A1 B2 4x xpl no4
- A1 B2 4x ppl no3
- A1 B2 4x xpl no3
- A1 B2 4x ppl no1
- A1 B2 4x xpl no1
- A1 B2 ppl
- A1 B2 xpl