Diabase Porphyry Dike

Title

Diabase Porphyry Dike

Identifier

SFM-7

Description

Hand Sample: Hypocrystalline, porphyritic, diabase with subhedral plagioclase and alkali feldspar (weathered to green) crystals approximately 1cm in length. Matrix is brown-black color. Weathered to white. Intensive weathering on one side to light brown.
Thin Section, XPL: 25% medium-grained subhedral plagioclase crystals in a matrix of green and dark green aciciular grains with low birefringence. Opaques present.

Date

1/20/1969

Contributor

Western Minerals, Inc.

Spatial Coverage

St. Francois Mtns. Batholith, Missouri

Accrual Method

Purchased from Western Minerals, Inc.

Number of Thin Sections

1