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U.S. Department of Energy
Office of Scientific and Technical Information

Geophysical-geological studies of possible extensions of the New Madrid Fault Zone. Annual report, 1982. Vol. 1

Technical Report ·
DOI:https://doi.org/10.2172/6215692· OSTI ID:6215692
An integrated geophysical/geologic program is being conducted to evaluate the rift complex hypothesis as an explanation for the earthquake activity in the New Madrid Seismic Zone and its extensions, to refine our knowledge of the rift complex, and to investigate the possible northern extensions of the New Madrid Fault Zone, especially its possible connection to the Anna, Ohio seismogenic region. Drillhole basement lithologies are being investigated to aid in tectonic analysis and geophysical interpretation, particularly in the Anna, Ohio area. Gravity and magnetic modeling combined with limited seismic reflection studies in southwest Indiana are interpreted as confirming speculation that an arm of the New Madrid Rift Complex extends northeasterly into Indiana. The geologic and geophysical evidence confirm that the basement lithology in the Anna, Ohio area is highly variable reflecting a complex geologic history. The data indicate that as many as three major Late Precambrian tectonic features intersect within the basement of the Anna area suggesting that the seismicity may be related to basement zones of weakness.
Research Organization:
Purdue Univ., Lafayette, IN (USA)
OSTI ID:
6215692
Report Number(s):
NUREG/CR-3174-Vol.1; ON: DE83902289
Country of Publication:
United States
Language:
English