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

Geologic units in Fredericksburg City, Virginia

Falmouth Intrusive Suite (Mississippian - Pennsylvanian) at surface, covers 0.3 % of this area

Falmouth Intrusive Suite - Granite, quartz monzonite, granodiorite, and tonalite

Lithology: granite; quartz monzonite; granodiorite; tonalite

Windsor Formation (Tertiary-Quaternary) at surface, covers 6 % of this area

Windsor Formation - Interbedded gravel, sand, silt, and clay; at altitudes to 85-95 ft. (top of unit).

Lithology: gravel; sand; silt; clay or mud

Ta River Metamorphic Suite (Cambrian) at surface, covers 1 % of this area

Ta River Metamorphic Suite - Amphibolite gneiss

Lithology: amphibolite; gneiss; schist; quartzite; biotite gneiss; felsic volcanic rock; gabbro; granite

Porphyroblastic Garnet-Biotite Gneiss (Proterozoic Y) at surface, covers 11 % of this area

Porphyroblastic garnet-biotite gneiss.

Lithology: biotite gneiss

Falls Run Granite Gneiss (Silurian) at surface, covers 4 % of this area

Falls Run Granite Gneiss - Granite

Lithology: granite

Shirley Formation (Quaternary) at surface, covers 13 % of this area

Shirley Formation - Interbedded gravel, sand, silt, clay, and peat; at altitudes to 35-45 ft. (top of unit).

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

Charles City Formation (Quaternary) at surface, covers 7 % of this area

Charles City Formation - Interbedded sand, silt, clay and minor gravel; at altitudes to 70-80 ft. (top of unit).

Lithology: sand; silt; clay or mud; gravel

Lower Tertiary Deposits (Tertiary) at surface, covers 6 % of this area

Lower Tertiary Deposits - Glauconitic quartz sand and clay-silt, shelly in part, minor sandy limestone and limey sand; may include the following formations: Brightseat, Aquia, Marlboro, Nanjemay, and Piney Point (Pamunkey Group); and Old Church.

Lithology: sand; silt; limestone

Chuckatuck Formation (Quaternary) at surface, covers 2 % of this area

Chuckatuck Formation - Interbedded gravel, sand, silt, clay, and minor peat; at altitudes to 50-60 ft. (top of unit).

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

Potomac Formation (Cretaceous) at surface, covers 26 % of this area

Potomac Formation - Pebbly, poorly sorted quartzo-feldspathic sand interbedded with sandy clay and silt; minor organic-rich clay and silt

Lithology: sand; clay or mud; silt

Chesapeake Group (Tertiary) at surface, covers 3 % of this area

Chesapeake Group - Fine- to coarse-grained sand, silt, clay; variably shelly and diatomaceous

Lithology: sand; silt; clay or mud

Pliocene Sand and Gravel (Tertiary) at surface, covers 17 % of this area

Pliocene Sand and Gravel - Sandy gravel, gravelly sand, poorly to well-sorted sands, and thin- to medium-beds of clay and silt, at altitudes from 170-320 ft. (top of unit).

Lithology: gravel; sand; clay or mud; silt

Holly Corner Gneiss (Proterozoic Z-Cambrian) at surface, covers 2 % of this area

Holly Corner Gneiss - Hornblende-biotite gneiss

Lithology: mafic gneiss