Nassawadox Formation: Butlers Bluff Member (VAQnb;0)

State	Virginia
Name	Nassawadox Formation: Butlers Bluff Member
Geologic age	Quaternary
Original map label	Qnb
Comments	Butlers Bluff Member; Coastal Plain, East of Chesapeake Bay From expanded explanation (ref. VA002): Butlers Bluff Member (Mixon, 1985). Pale-gray to light yellowish-gray, fine to coarse, cross-bedded, pebbly sand and sandy gravel comprising surficial deposits of upland (altitude 35-40 feet.). Diverse molluscan assemblage in lower part of unit, including Marginella, Mulinia, Nassarius, Spisula, Pleuromeris, and Olivella, indicates a shallow, nearshore-shelf depositional environment. Unit was deposited as a southward-building complex of spit-platform sands and shallow shoals and is as much as 60 feet in thickness. In subsurface, unit overlies 140 feet, or more, of pebbly to cobbly sand, clay silt, and muddy fine-grained sand of the Stumptown Memberof the Nassawadox Formation, which fills a late Pleistocene paleochannel of the Susquehanna River system.
Primary rock type	sand
Secondary rock type	gravel
Other rock types
Lithologic constituents	Major Unconsolidated > Coarse-detrital > Gravel Unconsolidated > Coarse-detrital > Sand
Map references	Digital Representation of the 1993 Geologic Map of Virginia", 2003, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, viewing software not included. This is a digital version of "Geologic Map of Virginia" published in 1993. Available from: https://www.dmme.virginia.gov/commerce/ [https://www.dmme.virginia.gov/commerce/]
Unit references	Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000 Digital Representation of the 1993 Geologic Map of Virginia - expanded explanation: 2003, Commonwealth of Virginia, Department of Mines, Minerals, and Energy, Divsion of Mineral Resources, Publication 147, 85 pp Digital Representation of the 1993 Geologic Map of Virginia", 2003, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, viewing software not included. This is a digital version of "Geologic Map of Virginia" published in 1993. Available from: https://www.dmme.virginia.gov/commerce/ [https://www.dmme.virginia.gov/commerce/]
Geographic coverage	Accomack - Northampton