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U.S. Geological Survey Open-File Report 03-221
A Pictorial Survey of the Bedrock Beneath Western Cape Cod, Massachusetts

 Detailed Bedrock Photographskip navbar


SAMPLE_ID:  81MW0005

DATE: 3/13/2001

Sample: 81MW0005 - Amphibolite


A foliated amphibolite, sample 81MW0005 is comprised of plagioclase (35%), hornblende (20%), biotite (20%), epidote (15%), quartz (9%), and trace oxides and sphene. Plagioclase is mostly fine grained and subhedral and occurs in the matrix. Fine-grained hornblende occurs as anhedral pleochroic green-tan crystals. Biotite is partly, but not entirely aligned in the foliation, suggesting that deformation took place before a secondary growth of biotite. Epidote is anhedral, and sometimes rimmed by biotite. Quartz occurs in 2 mm-thick aggregates and shows subgrain development.

Latitude: 41.64183

Longitude: -70.56901

Elevation of well site (m): 25.76

Elevation of the upper
bedrock surface (m):

Elevation of the
top of casing (m):

Total thickness of strata
penetrated by the well (m):

A Thin Section of this image is available.

Zip file with full resolution image. skip navbar

OFR03-221 Home | Introduction | Bedrock Photographs | GIS Data Catalog

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Coastal and Marine Geology
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