Digital Geologic Map of the Redding 1° x 2°; Quadrangle, Shasta, Tehama, Humboldt, and Trinity Counties, California

Open-File Report 2012-1228
By: , and 



The Redding 1° x 2 quadrangle in northwestern California transects the Franciscan Complex and southern Klamath Mountains province as well as parts of the Great Valley Complex, northern Great Valley, and southernmost Cascades volcanic province. The tectonostratigraphic terranes of the Klamath province represent slices of oceanic crust, island arcs, and overlying sediment that range largely from Paleozoic to Jurassic in age. The Eastern Klamath terrane forms the nucleus to which the other terranes were added westward, primarily during Jurassic time, and that package was probably accreted to North America during earliest Cretaceous time. The younger Franciscan Complex consists of a sequence of westward younging tectonostratigraphic terranes of late Jurassic to Miocene age that were accreted to North America from mid-Cretaceous through Miocene time, with the easternmost being the most strongly metamorphosed. The marine Great Valley sequence, of late Jurassic and Cretaceous age, was deposited unconformably across the southernmost Klamath rocks, but in turn was underthrust at its western margin by Eastern belt Franciscan rocks. Pliocene and Quaternary volcanic rocks and sediment of the Cascades province extend into the southeastern part of the quadrangle, abutting the northernmost part of the great central valley of California. This map and database represent a digital rendition of Open-File Report 87-257, 1987, by L.A. Fraticelli, J.P. Albers, W.P. Irwin, and M.C. Blake, Jr., with various improvements and additions.
Publication type Report
Publication Subtype USGS Numbered Series
Title Digital Geologic Map of the Redding 1° x 2°; Quadrangle, Shasta, Tehama, Humboldt, and Trinity Counties, California
Series title Open-File Report
Series number 2012-1228
DOI 10.3133/ofr20121228
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 Pamphlet: ii, 19 p.; Plate: 39.9 x 38.8 inches; GIS data: Readme TXT, Metadata TXT, Arc export files ZIP, Base image ZIP, Original map image ZIP
Country United States
State California
County Humboldt, Quadrangle, Shasta, Tehama, Trinity
Datum North American Datum 1927
Projection Transverse Mercator projection
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details