Southwestern Virginia Case Study

A3 Schist

Elizabeth A. Johnson

Outcrop and Hand Sample Photos and Videos

Click on the image to enlarge.

These outcrops are only a couple hundred meters down the road from the A3 amphibolite.  The schist shows distinctive foliation in outcrop.

The hand sample shows the complex foliation in more detail.  Pause the video when I show the side of the rock cut by a rock saw.

Thin Section Photos and Videos

Click on the image to make it larger. 1st = plane polarized light; 2nd = cross-polarized light.

Hornblende (green-brown in ppl, yellow-orange-blue in xpl), garnet, qtz, plagioclase.

 

Entire thin section scan. 1st = ppl; 2nd = xpl. Click on the image to make it larger.

This thin section is super interesting! Especially for thinking about deformation events. It was made from the cut side of the hand sample shown in the YouTube video above.

 

Media Attributions

  • OLYMPUS DIGITAL CAMERA
  • OLYMPUS DIGITAL CAMERA
  • A3 schist ppl 4x
  • A3 schist xpl 4x
  • A3 schist ppl
  • A3 schist xpl

License

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Introduction to Petrology Copyright © by Elizabeth A. Johnson is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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