Geologic map and database of the Roseburg 30 x 60 minute quadrangle, Douglas and Coos Counties, Oregon, USGS OFR 00-376

This database and accompanying plot files depict the distribution of geologic
materials and structures at a regional (1:100,000) scale. The report is
intended to provide geologic information for the regional study of materials
properties, earthquake shaking, landslide potential, mineral hazards, seismic
velocity, and earthquake faults. In addition, the report contains new
information and interpretations about the regional geologic history and
framework. However, the regional scale of this report does not provide
sufficient detail for site development purposes. In addition, this map does
not take the place of fault-rupture hazard zones designated by the Oregon State
Geologist. Similarly, the database cannot be used to identify or delineate
landslides in the region.

This digital map database, largely compiled from new mapping by the authors,
represents the general distribution of bedrock and surficial deposits of the
Roseburg 30 x 60 minute quadrangle along the southeastern margin of the Oregon
Coast Range and its tectonic boundary with Mesozoic terranes of the Klamath
Mountains. Together with the accompanying text files as PDF (rb_geol.pdf), it
provides current information on the geologic structure and stratigraphy of the
area covered. The database delineates map units that are identified by general
age and lithology following the stratigraphic nomenclature of the U.S.
Geological Survey. The scale of the source maps is 1:24,000, but the
Quaternary contacts and structural data have been much simplified for the
1:100,000-scale map and database. The spatial resolution (scale) of the
database is 1:100,000 or smaller.