Virginia Division of Geology and Mineral Resources - 3/6/08
Geologic Region Geologic Description Age of Rocks Major Rock Types Major Mineral Resources
Flat-lying to gently warped sedimentary rocks deposited in a west-facing Mississippian to
Appalachian Plateaus Sandstone, siltstone, shale Coal, natural gas
alluvial plain during and after Appalachian mountain building. Pennsylvanian
Passive-margin sedimentary sequence punctuated by orogenically
Cambrian to Limestone, dolostone, Lime, cement, shale, barite, silica,
Valley and Ridge induced clastic wedges. Later folded and thrust-faulted during
Appalachian mountain building.
Mississippian sandstone, shale, quartzite gypsum, lead, zinc, pyrite
High-grade basement gneisses unconformably overlain by low- to Crushed stone, iron, pyrite,
Middle to Late Granite, gneiss, greenstone,
Blue Ridge medium-grade rift-related metasediments and metavolcanic rocks. manganese, copper, feldspar,
Later uplifted and thrust-faulted during Appalachian mountain building.
Low- to medium-grade metasedimentary and igneous rocks formed in an
Western Piedmont elongate basin between the early Paleozoic margin of North America Early Paleozoic? Phyllite, gabbro Marble, slate, barite, vermiculite
and an offshore volcanic island belt.
Chopawamsic Terrane: Low- to medium-grade metavolcanic,
metasedimentary and igneous rocks formed in an offshore volcanic Cambrian- Gold, copper, pyrite, crushed
Granite, gneiss, schist, slate
island arc. Later accreted to North America during Paleozoic Ordovician stone, slate, kyanite
Central Piedmont Milton Terrane: Medium- to high-grade metavolcanic and igneous rocks;
Paleozoic? Granite, gneiss Crushed stone
of uncertain origin, possibly partly equivalent to the Carolina Terrane.
Carolina Terrane: Low- to medium-grade, strongly deformed
Piedmont metasedimentary and metavolcanic rocks formed in a volcanic island
Cambrian Slate, schist, quartzite Slate, gold, copper, tungsten
arc, later accreted to the eastern margin of North America during
Raleigh Terrane: High-grade metasedimentary, metavolcanic and
igneous rocks; high-grade metamorphic equivalents of Carolina Terrane Proterozoic Granite, gneiss, amphibolite Crushed stone, feldspar
Goochland Terrane: Very high-grade metavolcanic, metasedimentary,
Eastern Piedmont and igneous rocks; possibly a piece of ancient North American Proterozoic Granite, gneiss, amphibolite Crushed stone, feldspar
Roanoke Rapids Terrane: Low- to medium-grade metasedimentary,
Proterozoic Granite, gneiss, amphibolite Crushed stone, feldspar
metavolcanic and igneous rocks
Gently- to moderately-dipping sedimentary rocks with basalt flows and
Mesozoic Basins coal. Deposited in rapidly-subsiding rift basins during the breakup of Triassic-Jurassic Sandstone, shale, basalt Coal, crushed stone, barite
Pangea and the opening of the modern Atlantic Ocean.
Flat-lying to gently east-dipping, largely unconsolidated sediments. Cretaceous to Sand, gravel, clay, heavy mineral
Coastal Plain Sand, gravel, clay
The modern Atlantic passive margin seqence. Recent sands (titanium)