The Rock Beneath Stones River: A Civil War Battlefield on Ancient Sea Floor

The soldiers who fought at Stones River in the winter of 1862–63 were standing on the floor of an ancient sea. Every layer of bedrock under Stones River National Battlefield is Ordovician limestone, roughly 470 to 455 million years old — some of the oldest sedimentary rock exposed anywhere in Tennessee. Rainwater has been dissolving it ever since, leaving a karst landscape of sinkholes, caves and streams that run underground.

The battlefield

Stones River National Battlefield lies northwest of Murfreesboro, along the West Fork of Stones River in Rutherford County, central Tennessee. It commemorates the Battle of Stones River, fought from December 31, 1862, to January 2, 1863, for control of one of middle Tennessee's most productive farming regions and a central network of roads and railways. The battle ended in a strategic Union victory and ended the Confederate Army's attempt to move north into Kentucky.

The park was established as a national military park on March 3, 1927, and redesignated a national battlefield on April 22, 1960. It is not one tract but six, covering 263 hectares (650 acres) in all. From west to east:

1. General Rosecrans Headquarters Site
2. The main battlefield and the National Cemetery
3. The Artillery Monument and McFadden Ford
4. General Bragg Headquarters Site
5. Redoubt Brannan
6. Lunettes Palmer and Thomas, and Curtain Wall No. 2

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

How a sea floor ended up on a hilltop

The limestone was laid down in a marine basin that once covered the Mississippi River corridor of eastern North America. Four units are mapped inside the park:

By the end of the Paleozoic Era, these beds had been pushed upward as the Nashville Dome rose — which is why rocks this old sit at the surface here instead of deep underground. Once exposed, they began to dissolve. Chemical erosion of limestone is what creates karst, and it shapes the ground the park protects.

On top of the bedrock lie only thin, young deposits: alluvium — loose gravel, sand, silt and clay — along the West Fork corridor, and thin soils between outcrops of bare rock.

Stones River. NPS photo.

Part of a larger region

The park belongs to the Interior Low Plateaus Physiographic Province, and shares its geologic history and characteristic formations with a region that reaches far beyond the park's boundaries.

What has been mapped

Stones River is one of more than 270 natural resource parks covered by the NPS Geologic Resources Inventory, which produces:

• Scoping summaries — records of meetings where NPS staff and local geologists set the park's mapping plan and the contents of its report.
• Digital geologic maps — GIS files with a user guide and ancillary map information; newer products add Google Earth data and online map services.
• Reports — the park's setting and significance, notable features and processes, resource management issues and geologic history.
• Posters — a static PDF view of the map data, with aerial imagery or shaded relief on newer editions.

The cover of the park's Geologic Resources Inventory report.

A Soil Resources Inventory has also been completed for the park. Both inventories are available through the NPS DataStore.

Sources

Based on "NPS Geodiversity Atlas—Stones River National Battlefield, Tennessee," National Park Service, Geologic Resources Division, citing Thornberry-Ehrlich (2012), Stearns and Reesman (1986) and National Park Service (2014, 2016); a work of the United States government in the public domain.