Title
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.
Contributor
Western Minerals, Inc.
Is Part Of
http://www.geosciencecollections.milne-library.org/collections/show/17
Spatial Coverage
Karoo- Birds River, Eastern Cape, South Africa
Temporal Coverage
183-179 Ma (Jurassic)
Accrual Method
Purchased from Western Minerals, Inc.
Unit
Lesotho Formation
Number of Thin Sections
1