Preliminary map of selected post-Nevadan geologic features of the Klamath Mountains and adjacent areas, California and Oregon: A digital database

This map of selected post-Nevadan features is in a sense
supplementary to Map I-2148 (Geologic map of the Klamath Mountains,
compiled by W.P. Irwin, 1994). The map of selected post-Nevadan
geologic features is in large part a compilation of the published
work of many geologists (see Fig. 1--Index map showing sources of
data). The principal focus of Map I-2148 concerned the assemblage
of terranes that constitute the principal bedrock of the Klamath
Mountains. The terranes of the Klamath Mountains variously consist
of rocks that range from Cambrian to Late Jurassic and perhaps even
earliest Cretaceous age. All of these terranes have been subjected
to episodes of metamorphism, plutonism, and tectonism, including a
major widespread tectonic event which occurred mainly in Jurassic
time and which generally is referred to as the Nevadan orogeny.
The geologic map database delineates map units that are identified
by general age, lithology and clast size following the stratigraphic
nomenclature of the U. S. Geological Survey. The scale of the
source map limits the spatial resolution (scale) of the database to
1:500,000 or smaller.