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Geologic story of the North Cascades button
North Cascades National Park:
Forming depressions along faults
How horizontal movement on faults can produce depressions that fill with 	sediment.
Diagramatic map showing how horizontal movement on faults can produce depressions that fill with sediment.

One way to get extension or stretching of the crust while blocks of crust are sliding past each other along large faults is to have irregularities in the fault planes that open up gaps in the crust, or to have the faults discontinuous but arranged in an en echelon pattern.
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This site is a cooperative endeavor of the
US Geological Survey Western Earth Surface Processes Team
and the National Park Service.
Please share your comments and suggestions with us!
parkgeology@den.nps.gov

http://www.nature.nps.gov/grd/usgsnps/noca/sb11faultbasins.html
This page was last updated on 12/1/99
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Material in this site has been adapted from a new book, Geology of the North Cascades: A Mountain Mosaic by R. Tabor and R. Haugerud, of the USGS and published by The Mountaineers, Seattle