The Geology of Appomattox Court House: Piedmont Rock Under the Place the Civil War Ended

Geodiversity is the full variety of a park's natural geologic and soil resources and processes — rocks, minerals, sediments, fossils, landforms and the processes that shape them. The NPS Geodiversity Atlas, a product of the Geologic Resources Inventory, supports education, geoconservation, and management of a park's living and non-living parts together. This is its page for Appomattox Court House National Historical Park, Virginia.

The Geologic Resources Inventory report for the park.

The park

Established in 1930, the park covers 705 ha (1,743 ac) in Appomattox County, preserving the village of Appomattox Court House and its farms, forests and meadows. It commemorates the surrender of the Confederate Army of Northern Virginia to the Union Army on April 9, 1865 — the act that effectively ended the Civil War. Its sites include the surrender at the McLean House, the historic village, and the site of the Battle of Appomattox Court House.

The land

• Landscape: rolling hills and narrow, eroded stream valleys.
• Elevation: from 250 m (830 ft) on the highest hills to 194 m (638 ft) in the Appomattox River valley.
• Water: the Appomattox River and several tributaries, including Plain Run Branch, cross the park, which protects over 13 km (8.2 mi) of waterways. The Appomattox is a major tributary of the James River; they meet at Hopewell, Virginia.

That gentle terrain, set by the local geology and hydrology, decided where towns went, how troops camped, escaped and crossed rivers, where the railroads ran, and how troops and supplies moved. In many Civil War maneuvers, the side that knew the ground — its gaps, ravines, cuts, hills and ridges — held the advantage.

Plain Run Branch, a tributary of the Appomattox River. Its boulders are Cambrian metamorphic rock formed deep within the Earth along with the Appalachian Mountains. NPS photo by Brian Eick.

The rocks

The park lies in the western Piedmont, underlain by hard igneous and metamorphic rock — schists, phyllites, slates, gneisses and gabbros. This part of the Piedmont holds many belts of rock that were added to North America during repeated continental collisions and mountain-building events, which built the Appalachians — a history of more than 700 million years, down to today's weathering, erosion and human land use.

• Bedrock: the Fork Mountain Formation — porphyroblastic aluminosilicate mica schist, garnet-bearing biotite gneiss and amphibolite, with a band of greenstone and amphibole gneiss and a belt of felsic metatuff, mica schist and gneiss.
• Folding: at least four distinct periods (Marr and Sweet 1980). Large folds east of Appomattox include the Whispering Creek anticline and Long Island syncline.
• The Dryburg syncline: recent mapping south of the park found a northern extension of the Carolina Slate Belt along this upright, northeast-trending fold. It belongs to the Virgilina synclinorium, which runs south into North Carolina and holds metamorphosed volcanic and sedimentary rocks; it was likely folded during the Alleghanian Orogeny.
• Small-scale features: faults, fractures, mylonite zones and wavy foliation — thin alternating dark and light mineral bands. Joints and fractures are everywhere beneath the park, and most structures follow the northeast–southwest regional trend.

Keeping a Civil War landscape

Maintaining the Civil War landscape often means resisting geology:

• Runoff carries sediment off open ground into streams, ravines and gullies.
• Erosion wears down ridges, hills, foundations and earthworks, undermines bridge foundations, and cuts streams back into restoration areas.
• The sediment then fills low places — trenches, railroad cuts, stream ravines — blurring the historic landscape.
• Clearing trees for historical restoration removes stabilizing roots, which can increase erosion, add sediment to streams and undermine slopes.

Chemical weathering and seismicity also keep changing the land.

The park's geologic map from the Geologic Resources Inventory.

Region, maps and reports

The park shares its history and several formations with the wider Piedmont Province. The Geologic Resources Inventory makes scoping summaries, digital geologic maps, reports and posters for more than 270 natural resource parks; this park's are in the NPS DataStore, along with its completed Soil Resources Inventory. More: the park's nature and science pages and the Virginia Division of Geology and Mineral Resources.

Sources

Based on "NPS Geodiversity Atlas— Appomattox Court House National Historical Park, Virginia," National Park Service, drawing on Marr and Sweet (1980), Marr (1981), Nelson et al. (1999), the Virginia Division of Mineral Resources (2003) and Hackley et al. (2007); a work of the United States government in the public domain.