Bacons Castle Formation (VATb1;0)

State	Virginia
Name	Bacons Castle Formation
Geologic age	Tertiary
Original map label	Tb1
Comments	Coastal Plain From expanded explanation (ref. VA002): Tb1 / Tb2 Bacons Castle Formation (upper Pliocene, Coch, 1965). Gray, yellowish-orange, and reddish-brown sand, gravel, silt, and clay; constitutes surficial deposits of high plain extending from Richmond, eastward to the Surry scarp. Unit is subdivided into two members: Tb1, massive to thick-bedded pebble and cobble gravel grading upward into cross-bedded, pebbly sand and sandy and clayey silt, and Tb2, predominantly thin-bedded and laminated clayey silt and silty fine-grained sand. Tb2 is characterized by flaser, wavy, and lenticular bedding and rare to common clay-lined burrows including Ophiomorpha nodosa. Thickness is 0 to 70 feet.
Primary rock type	gravel
Secondary rock type	sand
Other rock types	silt; clay or mud
Lithologic constituents	Major Unconsolidated > Coarse-detrital > Gravel Minor Sedimentary > Coarse-detrital > Sand Unconsolidated > Fine-detrital > Silt Incidental Unconsolidated > Fine-detrital > Clay
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 - Greensville - Hanover - Henrico - King George - New Kent - Prince George - Richmond - Southampton - Spotsylvania - Stafford - Surry - Sussex - Westmoreland - Alexandria - Emporia - Petersburg - Richmond