An update of Quaternary faults of central and eastern Oregon

This publication updates previous fault maps of Oregon as a
contribution to the larger U.S. Geological Survey effort to produce
digital maps of active faults in the Pacific Northwest region. The new
map is derived from the 1992 fault map of Pezzopane, Nakata, and Weldon
that has seen wide distribution and has been reproduced in essentially
all subsequent compilations of active faults of Oregon. This
publication provides a substantial update of known active or suspected
active faults east of the Cascades. Improvements in the new map
include (1) many newly recognized active faults, (2) a linked ArcInfo
map and reference database, (3) more precise locations for previously
recognized faults on shaded relief quadrangles generated from USGS 30-m
digital elevations models (DEM), (4) more uniform coverage resulting in
more consistent grouping of the ages of active faults, and (5) a new
category of "possibly" active faults that share characteristics with
known active faults, but have not been studied adequately to assess
their activity. The distribution of active faults has not changed
substantially from the original Pezzopane, Nakata and Weldon map. Most
faults occur in the south-central Basin and Range tectonic province
that is located in the backarc portion of the Cascadia subduction
margin. These faults occur in zones consisting of numerous short
faults with similar rates, ages, and styles of movement. Many active
faults strongly correlate with the most active volcanic centers of
Oregon, including Newberry Craters and Crater Lake.