Please Note: This is an archived website. It is recommended to search on-line for revised or newer information.
Link to USGS Home Page CGS home USGS home

Home

Find Geologic Maps

About SCAMP

Southern California Geology

Links and Resources

Site Contents

Contact Us

mylonite

Photograph of mylonitic and cataclastic rock in the southeastern San Bernardino Mountains, southern California; pencil is about 6 inches (15 cm) long. These rocks occur in the upper plate of the Vincent Thrust, a zone of crustal movement and dislocation that underlies much of the Transverse Ranges Province. The original rock type probably was plutonic tonalite or quartz diorite that has been subjected to high-strain squeezing, stretching, and grinding of the mineral crystals to yield a rock whose original grain-to-grain relationships have been completely modified; such a high-strain rock is known as cataclasite or mylonite, depending on the brittle or ductile nature of the deformation style. Photo by J.C. Matti, USGS, July, 1979.

Return to Previous Page

blue line
Southern California Areal Mapping Project logo
SCAMP Home Page
USGS Geology, Minerals, Energy, and Geophysics
California Geological Survey
USGS Home || Search USGS

blue line

  U.S. Department of the Interior, U.S. Geological Survey
Maintainer: WESP team webmaster contact
Privacy Statement || Disclaimer || Accessibility
URL: http://geomaps.wr.usgs.gov/archive/scamp/html/aug790_21.html
This site last updated September 3, 2004 (ps)

First Gov