Skip to Main Content
Book Chapter

Aftershocks illuminate the 2011 Mineral, Virginia, earthquake causative fault zone and nearby active faults

By
J. Wright Horton, Jr.
J. Wright Horton, Jr.
U.S. Geological Survey, MS 926A, 12201 Sunrise Valley Drive, Reston, Virginia 20192, USA
Search for other works by this author on:
Anjana K. Shah
Anjana K. Shah
U.S. Geological Survey, P.O. Box 25046, Denver Federal Center, MS 964, Denver, Colorado 80225, USA
Search for other works by this author on:
Daniel E. McNamara
Daniel E. McNamara
U.S. Geological Survey, Geologic Hazards Science Center, 1711 Illinois St., Golden, Colorado 80401, USA
Search for other works by this author on:
Stephen L. Snyder
Stephen L. Snyder
U.S. Geological Survey, MS 954, 12201 Sunrise Valley Drive, Reston, Virginia 20192, USA
Search for other works by this author on:
Aina M. Carter
Aina M. Carter
3391 W. Old Mountain Road, Louisa, Virginia 23093, USA
Search for other works by this author on:
Published:
January 01, 2015

Deployment of temporary seismic stations after the 2011 Mineral, Virginia (USA), earthquake produced a well-recorded aftershock sequence. The majority of aftershocks are in a tabular cluster that delineates the previously unknown Quail fault zone. Quail fault zone aftershocks range from ~3 to 8 km in depth and are in a 1-km-thick zone striking ~036° and dipping ~50°SE, consistent with a 028°, 50°SE main-shock nodal plane having mostly reverse slip. This cluster extends ~10 km along strike. The Quail fault zone projects to the surface in gneiss of the Ordovician Chopawamsic Formation just southeast of the Ordovician–Silurian Ellisville Granodiorite pluton tail. The following three clusters of shallow (<3 km) aftershocks illuminate other faults. (1) An elongate cluster of early aftershocks, ~10 km east of the Quail fault zone, extends 8 km from Fredericks Hall, strikes ~035°–039°, and appears to be roughly vertical. The Fredericks Hall fault may be a strand or splay of the older Lakeside fault zone, which to the south spans a width of several kilometers. (2) A cluster of later aftershocks ~3 km northeast of Cuckoo delineates a fault near the eastern contact of the Ordovician Quantico Formation. (3) An elongate cluster of late aftershocks ~1 km northwest of the Quail fault zone aftershock cluster delineates the northwest fault (described herein), which is temporally distinct, dips more steeply, and has a more northeastward strike. Some aftershock-illuminated faults coincide with preexisting units or structures evident from radiometric anomalies, suggesting tectonic inheritance or reactivation.

You do not currently have access to this article.

Figures & Tables

Contents

GSA Special Papers

The 2011 Mineral, Virginia, Earthquake, and Its Significance for Seismic Hazards in Eastern North America

Geological Society of America
ISBN print:
9780813725093
Publication date:
January 01, 2015

References

Related

Citing Books via

Related Book Content
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal