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Bacons Castle Formation

Bacons Castle Formation - Gravel grading upward into sand and sandy clayey silt
State Virginia
Name Bacons Castle Formation
Geologic age Tertiary
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
Unconsolidated > Fine-detrital > Silt
Sedimentary > Coarse-detrital > Sand
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/
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/
Counties Arlington - Caroline - Charles City - Chesterfield - Dinwiddie - Essex - Fairfax - Greensville - Hanover - Henrico - King George - New Kent - Prince George - Richmond - Southampton - Spotsylvania - Stafford - Sussex - Westmoreland - Alexandria - Emporia - Richmond