Tholeiitic Gabbro

Title

Tholeiitic Gabbro

Alternative Title

Gabbro

Identifier

KBR-6

Description

KBR-3 through KBR-6 are a second gabbro mass, distinguished from the first by a repetition of the differentiation cycle. Between the location this sample was collected and the location KBR-7 was collected there is a thin gabbro pegmatite that was uncollected. This sample is medium grained and holocrystalline with a hypidiomorphic-granular texture.There are gray and black crystals, both about ranging from <1mm- 3mm. There is a reddish, rusty looking weathered surface. This rock has an average specific gravity.
Thin sections shown in plain and cross polarized light at 40x magnification.
The rock is made up of 65% plagioclase, 35% pyroxene, (mainly augite), and 3% 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

2