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The Cedars ultramafic mass, Sonoma County, California

Open-File Report 2012-1164

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Abstract

The Cedars ultramafic mass is a mantle fragment that consists of partially serpentinized spinel harzburgite and dunite. Compositional layering and a chromite lineation define a penetrative metamorphic foliation that almost certainly formed in the upper mantle. Although detailed petrofabric and mineral chemistry are presently lacking, it seems reasonable that the Cedars peridotite represents a slice of mantle tectonite that once formed the base of the Coast Range ophiolite, and not an abyssal peridotite tectonically emplaced within the Franciscan accretionary prism.

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
The Cedars ultramafic mass, Sonoma County, California
Series title:
Open-File Report
Series number:
2012-1164
Year Published:
2012
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Geology, Minerals, Energy and Geophysics Science Center
Description:
iii, 13 p.; maps col.; Plate: 1 Sheet: 15 x 15 inches
First page:
i
Last page:
13
Number of Pages:
16
Country:
United States
State:
California
County:
Sonoma County
Online Only (Y/N):
Y
Additional Online Files(Y/N):
Y