thumbnail

Rotational and accretionary evolution of the Klamath Mountains, California and Oregon, from Devonian to present time

Open-File Report 98-114

By:
and

Links

Abstract

The purpose of this report is to show graphically how the Klamath Mountains grew from a relatively small nucleus in Early Devonian time to its present size while rotating clockwise approximately 110°. This growth occurred by the addition of large tectonic slices of oceanic lithosphere, volcanic arcs, and melange during a sequence of accretionary episodes. The Klamath Mountains province consists of eight lithotectonoic units called terranes, some of which are divided into subterranes. The Eastern Klamath terrane, which was the early Paleozoic nucleus of the province, is divided into the Yreka, Trinity, and Redding subterranes. Through tectonic plate motion, usually involving subduction, the other terranes joined the early Paleozoic nucleus during seven accretionary episodes ranging in age from Early Devonian to Late Jurassic. The active terrane suture is shown for each episode by a bold black line. Much of the western boundary of the Klamath Mountains is marked by the South Fork and correlative faults along which the Klamath terranes overrode the Coast Range rocks during an eighth accretionary episode, forming the South Fork Mountain Schist in Early Cretaceous time.

Study Area

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Rotational and accretionary evolution of the Klamath Mountains, California and Oregon, from Devonian to present time
Series title:
Open-File Report
Series number:
98-114
Year Published:
1998
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Geology, Minerals, Energy and Geophysics Science Center
Description:
Poster: 38.72 x 22.07 inches; Geologic explanation
Country:
United States
State:
California;Oregon
Other Geospatial:
Klamath Mountains