Alluvium (VAal;0)

State	Virginia
Name	Alluvium
Geologic age	Quaternary
Original map label	al
Comments	Coastal Plain (Holocene epoch per Karen Hostettler) From expanded explanation (ref. VA002): Alluvium (Holocene). Fine to coarse gravelly sand and sandy gravel, silt, and clay, light- to medium-gray and yellowish-gray. Deposited mainly in channel, point-bar, and flood-plain environments; includes sandy deposits of narrow estuarine beaches, and mud, muddy sand, and peat in swamps and in fresh- and brackish-water marshes bordering tidewater rivers. Grades into colluvium along steeper valley walls at margins of unit. Mostly Holocene but, locally, includes low-lying Pleistocene (?) terrace deposits. As much as 80 feet thick along major streams.
Primary rock type	alluvium
Secondary rock type	clay or mud
Other rock types	sand
Lithologic constituents	Major Unconsolidated (Alluvial)
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	Arlington - Caroline - Charles City - Chesterfield - Dinwiddie - Essex - Fairfax - Gloucester - Greensville - Hanover - Henrico - Isle of Wight - James City - King and Queen - King George - King William - Lancaster - Middlesex - New Kent - Prince George - Prince William - Richmond - Southampton - Spotsylvania - Stafford - Surry - Sussex - Westmoreland - York - Alexandria - Colonial Heights - Emporia - Franklin - Hopewell - Newport News - Richmond - Suffolk - Williamsburg