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.
Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000.
Virginia Division of Mineral Resources, 2003, Digital Representation of the 1993 Geologic Map of Virginia, Publication 174, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, scale 1:500,000.