Fredericksburg and Spotsylvania: Battlefields on the Fall Line

Four Civil War battlefields — Fredericksburg, Chancellorsville, the Wilderness and Spotsylvania Court House — lie within a day's march of one another in Virginia, and all four are preserved in one park. They are there partly because of the ground: the park straddles the Fall Line, where the hard rock of the Piedmont meets the soft sediments of the Coastal Plain, and in 1862 that ground helped the Confederate army hold the road to Richmond.

The Geologic Resources Inventory report for the park. NPS

The park

The rocks

The park holds metamorphic, igneous and sedimentary rock ranging in age from the late Proterozoic–Ordovician to the Pliocene. Among the oldest is the Po River Metamorphic Suite — biotite gneiss, garnet-muscovite gneiss and schist.

The Fall Line

The park is split by the Fall Line: to the west, the rolling Piedmont of old, hard crystalline rock; to the east, the flat Coastal Plain of younger, softer sediment. Rivers crossing from one to the other drop over rapids — the "falls" that gave the line its name and that set where towns such as Fredericksburg grew.

Ground as a weapon

At the Battle of Fredericksburg in 1862, the Confederate army used the landscape along the Rappahannock River — its floodplains, its river terraces, and the ridges running north to south — to stop the Union advance. The same terrain helped block the way to the Confederate capital at Richmond for years.

The park's digital geologic map. NPS

Maps and reports

The NPS Geologic Resources Inventory has a scoping summary, a digital geologic map, a report and a poster for the park, and a Soil Resources Inventory is complete; both are in the NPS DataStore (saved searches 2867 and 2936). The park also describes its rivers and streams.

Sources

Written from "NPS Geodiversity Atlas—Fredericksburg and Spotsylvania National Military Park, Virginia," Geologic Resources Division, National Park Service; a work of the United States government in the public domain. It cites Thornberry-Ehrlich (2010) and the National Park Service (2016).