Tholeiitic Gabbro

Title

Tholeiitic Gabbro

Alternative Title

Gabbro

Identifier

KBR-2

Description

Samples KBR-1, KBR-2, and KBR-2A are from a vertical mass of gabbro showing progressive differentiation inward. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture. There are gray and black crystals, both ranging from <1mm- 3mm. There is a red rusty looking weathered surface. This rock has an average specific gravity.
Thin sections are shown in plain and cross polarized light at 40x magnification.
The gabbro is composed of 70% plagioclase, 30% pyroxene (mainly augite), and <1% opaques.

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