Brown Mountain intrusive Rhyolite

Title

Brown Mountain intrusive Rhyolite

Identifier

SFM-13

Description

Hand Sample: Porphyritic orange-pink rhyolite. Dominantly potassium feldspar with some black crystals. Weathers to brown-black and yellow-brown.
Thin Section, XPL: Fine-grained, well-weathered quartz and alkaline feldspar interspersed with fine-grained rectangular inclusions of mixed material. Opaques present.

Date

1/20/1969

Contributor

Western Minerals, Inc.

Spatial Coverage

St. Francois Mountains Batholith, Missouri

Accrual Method

Western Minerals, Inc

Number of Thin Sections

1