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The Mineral, Virginia (USA), earthquake of 23 August 2011 occurred at 6–8 km depth within the allochthonous terranes of the Appalachian Piedmont Province, rupturing an ~N36°E striking reverse fault dipping ~50° southeast. This study used the Interstate Highway 64 seismic reflection profile acquired ~6 km southwest of the hypocenter to examine the structural setting of the earthquake. The profile shows that the 2011 earthquake and its aftershocks are almost entirely within the early Paleozoic Chopawamsic volcanic arc terrane, which is bounded by listric thrust faults dipping 30°–40° southeast that sole out into an ~2-km-thick, strongly reflective zone at 7–12 km depth. Reflectors above and below the southward projection of the 2011 earthquake focal plane do not show evidence for large displacement, and the updip projection of the fault plane does not match either the location or trend of a previously mapped fault or lithologic boundary. The 2011 earthquake thus does not appear to be a simple reactivation of a known Paleozoic thrust fault or a major Mesozoic rift basin-boundary fault. The fault that ruptured appears to be a new fault, a fault with only minor displacement, or to not extend the ~3 km from the aftershock zone to the seismic profile. Although the Paleozoic structures appear to influence the general distribution of seismicity in the area, Central Virginia seismic zone earthquakes have yet to be tied directly to specific fault systems mapped at the surface or imaged on seismic profiles.

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