Piedmont Geology Along the Southeastern Fall Zone, Virginia and North Carolina

Science Center Objects

This task within the USGS NCGMP Piedmont-Blue Ridge Project aims to fill the void in geologic map coverage along the Fall Zone in southeastern Virginia and northeastern North Carolina, and forge strong cooperative ties within the NCGMP by combining resources across all three Program components by supporting DMME and NCGS STATEMAP and UNC–W EDMAP components with targeted geologic mapping and geochronologic/geochemical framework support at the 1:100,000-scale.

Geologic map coverage across the U.S, at detailed scales (1:100,000+) is incomplete, typically out of date, and not fully reconciled across map borders (Brock et al., 2017).  In Virginia, even after nearly two centuries of geologic mapping and resource inventory (Berquist and Whisonant, 2016), coverage is inadequate, particularly in the southeastern part of the State.   Similarly, coverage is poor in northeastern North Carolina, with nearly 2/3 7.5-minute quadrangles lacking comprehensive coverage along the Fall Line on the Roanoke Rapids 1:100,000-scale quadrangle.  Lack of adequate coverage equates to fundamental gaps in regional geologic framework knowledge, which hampers application of useable and reliable geologic information and data to geologic problems and issues.

The objectives of this Task are simple:   To develop a seamless geologic map database based on detailed and reconnaissance geologic mapping and to improve our understanding of the tectonic evolution of the eastern Piedmont through derivative geochronologic/geochemical studies.  A successful project will link on-going STATEMAP geologic mapping in the Richmond MSA by Virginia DMME across the state line with commensurate STATEMAP and EDMAP work in northeastern North Carolina by the NCGS and UNC–W to resolve state boundary edge-match issues and correlation problems (e.g., see Burton and Southworth, 2017 who address similar correlation problems in the Piedmont of Maryland and Virginia).  This unifying bi-state geologic framework model will be applied to specific local and regional earth systems problems – groundwater modeling (e.g., McFarland and Bruce, 2006) and derivative studies (e.g., source identification for naturally-occurring arsenic and chromium at toxic levels in groundwater and soil), mineral resource exploration (e.g., aggregate resources, heavy minerals, strategic minerals, and tungsten – Sweet et al., 2016), and geologic hazard mitigation (e.g., radon gas – Eaton et al., 2016).  

 

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References:

Berquist, C.R. and Whisonant, R.C., 2016, A brief history of geological research in Virginia, in Bailey, C.M., Sherwood, W.C., Eaton, L.S., and Powars, D.S., eds., The Geology of Virginia:  Virginia Museum of Natural History Special Publication 18, pgs. 1-16.

Brock, J.C., and others, 2017, The 2018–2027 U.S. Geological Survey National Cooperative Geologic Mapping Program Decadal Strategic Plan:  U.S. Geological Survey, unpublished administrative report, 3 p. 

Burton, W.C. and Southworth, S., 2017, Discontinuities and connections in Piedmont and Blue Ridge terranes from Maryland and Virginia:  Geological Society of America Abstracts with Programs, v. 49, n. 3, doi: 10.1130/abs/2017SE-290224.

Eaton, L.S., Kochel, R.C., Hubbard, D.A., Jr., Simoni de Cannon, F.V., and Mose, D.G., 2016, Geologic Hazards of Virginia, in Bailey, C.M., Sherwood, W.C., Eaton, L.S., and Powars, D.S., eds., The Geology of Virginia:  Virginia Museum of Natural History Special Publication 18, pgs. 381-406.

McFarland, E.R., and Bruce, T.S., 2006, The Virginia Coastal Plain Hydrogeologic Framework: U.S. Geological Survey Professional Paper 1731, 118 p., 25 pls. (available online at http://pubs.water.usgs.gov/pp1731/)

Sweet, P.C., Lassetter, W.L., Sherwood, W.C., 2016, Non-fuel mineral resources in Virginia, in Bailey, C.M., Sherwood, W.C., Eaton, L.S., and Powars, D.S., eds., The Geology of Virginia:  Virginia Museum of Natural History Special Publication 18, pgs. 407-442.