USGS - science for a changing world

Geology and National Parks

 

Geology, Minerals, Energy and Geophysics Science Center home

The information found here reflects completed USGS work. The content of this page is static and has not been updated since the mid 2000's.

Visual Glossary

Flattened rock with foliation versus stretched rock with lineation.
Flattened rock with foliation versus stretched rock with lineation. Illustration by Anne Crowder.

Foliation

Foliation forms when pressure squeezes flat or elongate minerals within a rock so they become aligned. These rocks develop a platy or sheet-like structure that reflects the direction that pressure was applied in. Slate, schist, and gneiss (pronounced 'nice') are all foliated metamorphic rocks.

Folded gneiss. It's not hard to see that this metamorphic rock, called gneiss, has been foliated, then intensely folded. Photo by Edward P. Klimasauskas, USGS.
CLICK THE BACK BUTTON OF YOUR BROWSER TO RETURN TO THE PREVIOUS PAGE

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://geomaps.wr.usgs.gov/parks/deform/gfoliation.html
Page Contact Information: G & G Webmasters
Page Last Modified: 25-Apr-2017@09:48