Relation of Pulaski and Seven Springs faults in southwestern Virginia

The Marion-Rural Retreat area of Smyth and Wythe counties, Virginia, contains the “missing link” to the long assumed, but heretofore unproven, continuation of the Pulaski fault trace southwestward around the structurally complex Marion dome area. The Seven Springs fault of Cooper (1936) has long been assumed to be the southwestward continuation of the extensive Pulaski fault; however, the linkage of these two faults was not established or understood. ·

Through detailed field mapping of mainly the Elbrook Dolomite, which is not known to exist northwest of the Pulaski fault block, and the time equivalent Honaker-Nolichucky succession, which is not known to exist southeast of the Saltville fault block, the writer has been able to delineate the trace of the Pulaski fault in this area.

The fault shown on Butts' (1933) ”Valley Map” as extending east along the southeast base of Little Brushy Mountain from Marion to a point north of Groseclose, is not the Pulaski fault but instead a separate and distinct, high angle reverse fault called by Cooper (1936) the Hungry Mother fault. Near the center of the area, the Pulaski fault passes over the Hungry Mother fault and veers south away from the base of Little Brushy Mountain toward Atkins, Smyth County, Virginia, where careful mapping of the formations along the Valley of the Middle Fork of the Holston River affords a reliable criterion for joining the trace of the Pulaski fault with that of the Seven Springs fault.