Title
Pyroxene-quartz-plagioclase gneiss
Identifier
AD-3
Description
This specimen consists of 50-60% andesine, 20-30% quartz, and minor pyroxene and hornblende. Associated with this lithology are 2-6 inch layers of pyroxene-plagioclase granulite and amphibolite. It is believed that the Royal Mountain Member gneiss represents a metamorphosed layered instrusion of overall tonalitic composition. Numerous internal features, such as xenoliths and possible slump structures, support this hypothesis.
Thin section shows plagioclase, quartz and hornblende.
Thin section shows plagioclase, quartz and hornblende.
Date
1980
Contributor
Western Minerals Inc.
Spatial Coverage
Adirondack Highlands-collected from a large road cut on the east side of NY routes 10 &29A across from the Canada Lake Store.
Temporal Coverage
Precambrian
Accrual Method
Purchased from Western Minerals Inc.
Unit
Royal Mountain Member, Green Lake Formation
Number of Thin Sections
1