skip headerUSGS: science for a changing world -
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:  95MW0208

DATE: 8/5/2002

Sample: 95MW0208 - Felsic Mylonite


Sample 95MW0208 is a quartz dioritic mylonite containing plagioclase (70%), quartz (20%), sericite (5%), K-feldspar (2%), chlorite (2%), epidote (1%), and trace oxides and sphene. Plagioclase is extremely seritized and shows undulose extinction. Quartz is dramatically recrystallized to show elongated grains and micro scale ribbon-like textures. Non-recrystallized quartz shows subgrain development and undulose extinction. K-feldspar may be antiperthitic in origin, and exhibits tartan twinning in larger grains. Chlorite probably has replaced biotite. Sphene shows brittle fracturing, which probably occurred during mylonitization. 

Latitude: 41.61484

Longitude: -70.5502

Elevation of well site (m): 12.36

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

skip footer
[an error occurred while processing this directive]