Wachapreague Formation (VAQwa;0)

State	Virginia
Name	Wachapreague Formation
Geologic age	Quaternary
Original map label	Qwa
Comments	Coastal Plain, East of Chesapeake Bay From expanded explanation (ref. VA002): Wachapreague Formation (upper Pleistocene, Mixon, 1985). Coarsening upward sequence, includes a lower member of clayey and silty, fine to very-fine, gray sand interbedded with clay-silt and an upper member of medium to coarse, gravelly sand. Mollusks, including Mesodesma arctatum and Siliqua costata, and ostracode assemblages dominated by Elofsonella concinna and Muellerina canadensis indicate cooling ocean temperatures during deposition of unit. Pollen assemblage dominated by pine, spruce, birch, and alder suggests cool- to cold-temperate conditions in nearby land areas. Unit is surficial deposit of narrow, arcuate coastal lowland ranging in altitiude from sea level, at eastern border with Holocene barrier-lagoon complex, to about 15 feet at toe of ocean-facing scarp forming western boundary. Thickness is 0 to 40 feet..
Primary rock type	sand
Secondary rock type
Other rock types
Lithologic constituents	Major 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