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Mineral Resources > Online Spatial Data > Geology > by state > Virginia Geology

Geologic units in Accomack county, Virginia

[Additional scientific data in this geographic area]

Nassawadox Formation: Occohannock Member (Quaternary) at surface, covers 2 % of this area

Nassawadox Formation: Occohannock Member - Muddy fine- to medium-grained sand, at altitudes to 30 ft. (top of unit).

Lithology: sand

Marsh and Intertidal Mud Deposits (Quaternary) at surface, covers 22 % of this area

Marsh and Intertidal Mud Deposits - Organic-rich clay and silt

Lithology: clay or mud; silt

Nassawadox Formation: Butlers Bluff Member (Quaternary) at surface, covers 2 % of this area

Nassawadox Formation: Butlers Bluff Member - Fine- to coarse-grained pebbly sand and sandy gravel, at altitudes to 40 ft. (top of unit).

Lithology: sand; gravel

Beach Sand and Dune Sand Deposits (Quaternary) at surface, covers 5 % of this area

Beach Sand and Dune Sand Deposits - Fine- to coarse-grained quartz sand, poorly to well-sorted.

Lithology: beach sand; dune sand

Quaternary Deposits Undivided (Quaternary) at surface, covers 0.5 % of this area

Quaternary Deposits Undivided - Undifferentiated gray to buff sand and gravel, gray to brown lignitic silt and clay, occasional boulders, and rare shell beds. Surficial deposits occur as intercalated fluvial sands and marsh muds (e.g. in upstream floodplain of the Wicomico and Nanticoke Rivers), well-sorted, stablized dune sands (e.g. eastern Wicomico County), shell-bearing estuarine clays and silts (e.g. lower Dorchester County) and Pocomoke River basin of Worcester County), and beach zone sands (e.g. Fenwick and Assateague Islands). Wisconsin to Holocene in age. Subsurface deposits of pre-Wisconsin age consist of buff to reddish-brown sand and gravel locally incised into Miocene sediments (e.g. Salisbury area), estuarine to marine white to gray sands, and gray to blue, shell-bearing clays (e.g. Worcester County).

Lithology: sand; gravel; silt; clay or mud; dune sand; beach sand

Kent Island Formation (Quaternary) at surface, covers 21 % of this area

Kent Island Formation - Medium- to coarse-grained sand and sandy gravel grading upward into poorly- to well-sorted fine- to medium-grained sand, in part clayey and silty, at altitudes from sea level to about 20 ft. (top of unit).

Lithology: sand; gravel

Joynes Neck Sand (Quaternary) at surface, covers 6 % of this area

Joynes Neck Sand - Fine- to coarse-grained sand coarsening downward to gravel and sand, at altitudes to 26 ft. (top of unit).

Lithology: sand; gravel

Omar Formation - Accomack Member: (Quaternary) at surface, covers 28 % of this area

Omar Formation - Accomack Member: sand, gravel, silt, clay, and peat; at altitudes to 50 ft.

Lithology: sand; gravel; silt; clay or mud; peat

Wachapreague Formation (Quaternary) at surface, covers 5 % of this area

Wachapreague Formation - Coarsening-upward sequence from lower muddy fine-grained sand to upper medium- to coarse-grained gravelly sand, at altitudes from sea level to about 15 ft. (top of unit).

Lithology: sand