<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Russell L. Wheeler</dc:contributor>
  <dc:creator>Anthony J. Crone</dc:creator>
  <dc:date>2000</dc:date>
  <dc:description>The USGS is currently leading an effort to compile published geological information on&#13;
Quaternary faults, folds, and earthquake-induced liquefaction in order to develop an internally&#13;
consistent database on the locations, ages, and activity rates of major earthquake-related features&#13;
throughout the United States. This report is the compilation for such features in the&#13;
Central and Eastern United States (CEUS), which for the purposes of the compilation, is&#13;
defined as the region extending from the Rocky Mountain Front eastward to the Atlantic&#13;
seaboard. A key objective of this national compilation is to provide a comprehensive database&#13;
of Quaternary features that might generate strong ground motion and therefore, should be considered&#13;
in assessing the seismic hazard throughout the country. In addition to printed versions&#13;
of regional and individual state compilations, the database will be available on the World-Wide&#13;
Web, where it will be readily available to everyone. The primary purpose of these compilations&#13;
and the derivative database is to provide a comprehensive, uniform source of geological information&#13;
that can by used to complement the other types of data that are used in seismic-hazard&#13;
assessments.&#13;
Within our CEUS study area, which encompasses more than 60 percent of the continuous U.S.,&#13;
we summarize the geological information on 69 features that are categorized into four classes&#13;
(Class A, B, C, and D) based on what is known about the feature's Quaternary activity. The&#13;
CEUS contains only 13 features of tectonic origin for which there is convincing evidence of&#13;
Quaternary activity (Class A features). Of the remaining 56 features, 11 require further study in&#13;
order to confidently define their potential as possible sources of earthquake-induced ground&#13;
motion (Class B), whereas the remaining features either lack convincing geologic evidence of&#13;
Quaternary tectonic faulting or have been studied carefully enough to determine that they do not&#13;
pose a significant seismic hazard (Classes C and D).&#13;
The correlation between historical seismicity and Quaternary faults and liquefaction features&#13;
in the CEUS is generally poor, which probably reflects the long return times between successive&#13;
movements on individual structures. Some Quaternary faults and liquefaction features&#13;
are located in aseismic areas or where historical seismicity is sparse. These relations indicate&#13;
that the record of historical seismicity does not identify all potential seismic sources in the&#13;
CEUS. Furthermore, geological studies of some currently aseismic faults have shown that the&#13;
faults have generated strong earthquakes in the geologically recent past. Thus, the combination&#13;
of geological information and seismological data can provide better insight into potential&#13;
earthquake sources and thereby, contribute to better, more comprehensive seismic-hazard&#13;
assessments.</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.3133/ofr00260</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>U.S. Dept. of the Interior, U.S. Geological Survey,</dc:publisher>
  <dc:title>Data for Quaternary faults, liquefaction features, and possible tectonic features in the Central and Eastern United States, east of the Rocky Mountain Front</dc:title>
  <dc:type>reports</dc:type>
</oai_dc:dc>