Document Type
Thesis
Abstract
The Quaker Run high-strain zone (QRHSZ) in the Blue Ridge province of northern Madison County, Virginia, is a dip-slip high-strain zone characterized by top-to-thenorthwest, reverse sense-of-shear. The zone accommodated approximately 1.5 ± 0.5 km of displacement and is kinematically related to a family of anastomosing Paleozoic high-strain zones. The traditional tectonic model for the Blue Ridge suggests that two Grenvillian massifs (the Pedlar and Lovingston) formed at different crustal depths and were juxtaposed during Paleozoic thrusting (Bartholomew et al., 1981 ). The QRHSZ does not separate Pedlar from Lovingston rocks and did not accommodate enough displacement to separate the two massifs. Thus the art}:lolomew interpretation should be reevaluated. Field and petrographic relations indicate a gradational contact between Mesoproterozoic chamockites and biotite granitoids. The contact is a diffuse zone~ 1km wide and is characterized by a transitional mineral assemblage. An alternative tectonic model for the Blue Ridge suggests Lovingston-type biotite granitoids were derived from Pedlar chamockites via hydrous metamorphic reactions (Evans, 1991 ). Petrographic and geochemical data from Madison County indicate the chamockites and biotite granitoids were hydrously altered and support the interpretation that biotite granitoids were nonisochemically derived from chamockites.
Date Awarded
2000
Department
Geology
Advisor 1
Christopher M. Bailey
Recommended Citation
Berquist, Peter J., "High-Strain Zones and Contact Relationships in he Basement Complex of the Blue Ridge Province in Madison County, Virginia" (2000). Geology Senior Theses. William & Mary. Paper 59.
https://scholarworks.wm.edu/geologyseniors/59
