Amphibolite_from_under_Cape_Cod_USA.jpg
Size of this preview:
596 × 600 pixels
.
Other resolutions:
238 × 240 pixels
|
600 × 604 pixels
.
Summary
| Description |
English:
Foliated amphibolite, sample 81MW0005, a borehole sample from under Cape Cod in Massachusetts in USA. It is made of the minerals 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.
|
| Date | |
| Source | U.S. Geological Survey Open-File Report 03-221 (2004) A Pictorial Survey of the Bedrock Beneath Western Cape Cod, Massachusetts , sample 81mw0005 http://pubs.usgs.gov/of/2003/of03-221/htmldocs/bedrock_photos/81mw0005.htm |
| Author | B.W. Hallett, V. F. Paskevich, L.J. Poppe, S.G. Brand, and D.S. Blackwood |
| Object location |
|
View this and other nearby images on: OpenStreetMap |
|
|---|
Licensing
|
This image is in the
public domain
in the United States because it only contains materials that originally came from the
United States Geological Survey
, an agency of the
United States Department of the Interior
. For more information, see
the official USGS copyright policy
.
|
|