Age and provenance of the western Piedmont metagraywackes: Evidence for pre-Taconic (Cambrian ) collisional tectonics in central Virginia

Conference · Tue Mar 01 04:00:00 EST 1994 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:6887984

Evans, N H ^[1]

---

1. Virginia Div. of Mineral Resources, Charlottesville, VA (United States)

In the western Piedmont of central Virginia, Early Paleozoic passive-margin cover rocks on the southeastern limb of the Blue Ridge anticlinorium are overridden from the southeast by polydeformed metagraywackes along the Mountain Run fault zone, where synmetamorphic Taconic contractional faults and related microstructures are overprinted by later contractional and extensional structures. The metagraywackes are turbidites that contain ultramafic, mafic, and granitic plutonic rock fragments, mafic and felsic volcanic detritus, and greenschist-facies detrital mineral grains. The metagraywackes are equivalent in part to the Mine Run Complex and the Mather Gorge Formation in northern Virginia, and are intruded by the Cambrian-age Melrose granite (515 Ma). It is proposed that the metagraywackes were shed westward into an Early Paleozoic marginal sea, adjacent to the North American passive margin, from terrane(s) incorporating lithofacies presently juxtaposed in the central Piedmont of Virginia and Maryland.

• OSTI ID: 6887984
• Report Number(s): CONF-9404221--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 26:4
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
DEVELOPED COUNTRIES
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGY
GRAYWACKE
NORTH AMERICA
PETROLOGY
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
TECTONICS
USA
VIRGINIA