Basalt Dike

Title

Basalt Dike

Identifier

SFM-10

Description

Hand Sample: Aphanitic brown-black basalt with microcrystalline inclusions of quartz and alkali feldspar. Weathers to yellow orange. Part of a dike cross cutting granite at the Cornwall Quarry.
Thin Section, XPL: 15% medium-grained plagioclase crystals in 75% matrix of very-fine-grained opaques, plagioclase, and biotite. Very fine veins of a darker material run through the sample.

Date

1/20/1969

Contributor

Western Minerals, Inc

Spatial Coverage

St. Francois Mtns. Batholith, Missouri Cornwell Quarry

Accrual Method

Purchased from Western Minerals Inc.

Number of Thin Sections

1