Volcanic Breccia

Identifier

KBR-19

Description

This is a volcanic breccia from the farm Murrelfontein adjacent to the contact with the gabbro unit. It includes partially melted glass and tridymite, a high temperature polymorph of quartz, and has a brecciated appearance. The breccia has a allotriomorphic- granular texture and is holocrystalline. Coarse, anhedral, chaotic-looking dark black crystals (3-12mm) are surrounded by slightly lighter colored, smaller anhedral crystals (2 mm -6 mm). There are trace olivine phenocrysts (2 mm).

Date

No date given.

Is Part Of

http://www.geosciencecollections.milne-library.org/collections/show/17

Temporal Coverage

Accrual Method

Purchased from Western Minerals, Inc.

Number of Thin Sections

1