Geology of Fort Pulaski National Monument, Georgia

The park

Fort Pulaski National Monument lies between Savannah and Tybee Island on the Georgia coast, in northeastern Chatham County.

• Proclaimed: October 15, 1924.
• Size: about 2,275 hectares (5,623 acres), on parts of Cockspur Island and McQueen's Island.
• The fort: a masonry coastal fortification of the kind built to protect U.S. harbors after the War of 1812. Built 1829–1847 at the mouth of the Savannah River, it took 25 million bricks, with a complex network of dikes, ditches and drains.
• Its battle: in 1862, new, experimental rifled artillery breached its massive walls and forced the Confederate garrison to surrender. Afterward, the fort became a refuge for freedom seekers until the end of the Civil War.
• The marsh: much of the monument is undisturbed salt marsh, part of NOAA's national system of Marine Protected Areas for its ecological value.

Inside the fort: the veranda and parade ground. National Park Service.

The ground it stands on

Fort Pulaski is in the Atlantic Coastal Plain — gently sloping land made of marine terraces that get younger and lower toward the ocean. It belongs to the plain's Sea Island Section.

Georgia's coastal islands were built by rivers draining the Piedmont into the Atlantic. Their sediment was laid down as washover terraces migrating landward, which stabilized about 4.5 thousand years ago (Hayes 1988).

The monument's geology is young:

The fort's outer wall and moat. National Park Service.

Maps, reports and soils

The Park Service's Geologic Resources Inventory makes digital geologic maps and reports for more than 270 natural resource parks. Its products for Fort Pulaski — scoping summaries, digital geologic maps, reports and posters — are on the NPS DataStore. A completed Soil Resources Inventory for the monument is there too (saved search).

More: Fort Pulaski — natural features and ecosystems · NPS Geodiversity Atlas.

Sources

Based on "NPS Geodiversity Atlas—Fort Pulaski National Monument," National Park Service; a work of the United States government in the public domain. The source's title places the monument in South Carolina; it is in Georgia, as its own introduction says. The source's "barrier stands" is read as barrier strands.