Depositional and tectonic significance of Upper Cenozoic deposits in the vicinity of Richmond, Virginia

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6463845

Johnson, G H; Peebles, P C

Upper Cenozoic deposits ranging in age from late Miocene to Holocene rest unconformably on older Tertiary, Mesozoic, and Paleozoic formations in the vicinity of Richmond, Virginia. The Eastover (Upper Miocene), Yorktown (Lower and Middle Pliocene) and Bacons Castle (Upper Pliocene), are comprised of a thin, basal transgressive marine gravelly sand overlain by fossiliferous marine sand and silt which grades upward into clayey or sandy silt. The basal sand thins and decreases in grain size away from the shoreline and the mouths of major rivers. In contrast to the Tertiary units, the Pleistocene formations (Windsor, Charles City, Chuckatuck, Shirley, and Tabb) are of fluvial-estuarine origin and occur beneath a succession of terraces inset into older deposits along the major rivers in the Richmond area. High angle reverse faults, broad folds, southward shifting depocenters, and the distribution of sediments in late Tertiary deposits of south-eastern Virginia indicate differential movement during late Tertiary time. Differential movement appears to have ceased following the deposition of the Yorktown Formation as evidenced by the lack of faulting or tilting in the Bacons Castle or younger formations.

• Research Organization: College of William and Mary, Williamsburg, VA (USA)
• OSTI ID: 6463845
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
580201 -- Geophysics-- Seismology & Tectonics-- (1980-1989)
CENOZOIC ERA
DEFORMATION
DEPOSITION
FEDERAL REGION III
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FORMATIONS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
NORTH AMERICA
ROCKS
SEDIMENTARY ROCKS
STRATIGRAPHY
TECTONICS
USA
VIRGINIA