Spears Mountain, a monadnock in the central Piedmont of Virginia.
Spears Mountain- a Monadnock
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Saprolite
Saprolite exposed below soil in an excavation in the Piedmont.
Fall Zone
The Fall Zone delineates the boundary between the Coastal Plain and the Piedmont. Here rivers draining the Piedmont drop steeply to sea level and in the process form dramatic rapids.
James River profile (red line) from the Piedmont, west of Richmond, through the Fall Zone to the Coastal Plain. Notice the dramatic change in gradient from 1-2’ per mile above the Fall Zone to 14’ per mile in the Fall Zone. The vertical steps in the Piedmont are due to dams along the river, the blue dashed line traces the original pre-dam profile.
False color imagery of Belle Isle in Richmond, Virginia and the rapids in the Fall Zone.
The Neoproterozoic Lynchburg Group
The Neoproterozoic Lynchburg Group is a thick sequence of metasedimentary rocks exposed in the eastern Blue Ridge from northern to south-central Virginia. These deposits range from coarse-grained conglomerate to fine-grained mudstone.
Boulder conglomerate in the Rockfish Conglomerate at the base of the Neoproterozoic Lynchburg Group in Nelson County. Click here to learn more about the Rockfish Conglomerate.
Fine-grained laminated mudstone and siltstone from the Lynchburg Group in Albemarle County.
Siluro-Devonian cross bedded carbonate strata
Cross bedded Siluro-Devonian carbonate strata exposed in the Valley & Ridge province.
Grenvillian Gneiss
Catoctin Columns
Well-exposed columnar joints in the Ediacaran Catoctin Formation. These columns formed as cooling cracks as 570 to 550 Ma lava flows solidified. Exposure on Compton Mountain in Shenandoah National Park.
K-feldspar Granite, Blue Ridge
Coarse-grained K-feldspar granite of Mesoproterozoic age (~1.05 Ga) exposed in the Blue Ridge province Nelson County, Virginia. photo by C. M. Bailey
Karst Topography
Karst topography, including sinkholes and caves, developed on soluble limestone in the Valley & Ridge province, Russell County, Virginia.
Trellis Drainage Pattern
Trellis drainage pattern in the Valley & Ridge at the headwaters of the James, Potomac, and Ohio river systems in northwestern Virginia and eastern West Virginia.