GEOS5505 Lab 1 Process vs microstructure
CET/UWA Microstructure Course
| TOC | Lecture 1 2 3 4 a b  5 a b | Lab 1 a b c 2 a b c 3 a b 4 a b 5 a b | Glossary Table 1 2 3 4 5 Index | GEOS5505 Lab 1 | GEOS5505 Lab 2|

GEOS 5505 Microstructure Prac Day 3

Microstructures

1) In this example we will deconstruct the history of a thin section.

This thin section contains four main minerals quartz, cordierite, garnet and biotite. Describe the shape and internal texture of each mineral, their relationships at grain boundaries, and overall textural relationships. Describe the evidence for the timing relationships of the different minerals and textures in this sample. You should use annotated screen shots to support your answers.

Click on image to access virtual thin section



2) Place this sequence of thin sections in order of increasing temperature and pressure, and describe the microstructual differences between these rocks. You should use annotated screen shots to support your answers, but don't worry if you can't recognise the minerals, as you can still describe the textures.

Click on images to access virtual thin sections



Be careful here:

  • A rock can have a small grain size because it is an original fine-grained rock, or because a coarse-grained rock has been strongly deformed.
  • A rock with a strong foliation may just be a shale displaying finely laminated bedding.
  • Look for evidence of metamorphic mineral growth, and interactions between deformation and mineral growth.
  • In coarser grained rocks, look for evidence of deformation microstructures within grains.


    • Rock_A


    Rock_B


    Rock_C


    Rock_D


    Rock_E


    CET/UWA Deformation Microstructures Course Lab 3 - Deformation Mechanisms

    Copyright Mark Jessell & Paul Bons 2019