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Coastal Heritage - Fall 2018
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First Impacts: Natural Systems Face Sea-Level Rise
VOLUME 31, NUMBER 3, Fall 2018            
                                                                                                                back to main story  

Archaeology: Capturing the Past Before It’s Too Late

By Joey Holleman

Millions of years ago, Earth’s oceans were nearly 230 feet higher, lapping at shores in what is now the Sand Hills belt of South Carolina from Aiken to Cheraw. Just 21,000 years ago, the ocean was about 410 feet lower than today, all the way out to the edge of the continental shelf.

In more recent times, the fluctuations have been smaller, allowing traces of human history to amass along the coast.

Archaeologists have been chipping away for decades at clues left behind in shell middens, or mounds, created by people who inhabited the South Carolina coast 4,000 years ago. The mounds themselves inform about social structures, as they likely were built by large groups gathered in the same spot at the same time of year for multiple years, says Sean Taylor, an archaeologist with the S.C. Department of Natural Resources (SCDNR).

The building blocks of the middens – predominately oyster and clam shells – also reveal details of the coastal ecology of the times. Tools made of shell and bone and decorated pottery hint of lives beyond the day-to-day struggle to survive.

Hundreds of shell middens dot the South Carolina coast, including publicly accessible shell rings at Sea Pines on Hilton Head Island and near the Sewee Visitor and Environmental Education Center in Awendaw. Others are on private land or surrounded by saltwater marshes. Some are underground.

On Botany Bay Plantation’s Pockoy Island, archaeologists spent three weeks in 2018 studying a recently discovered shell ring. LiDAR (Light Detection and Ranging) technology used to map elevation change in great detail located what appeared to be a ring in the island’s maritime forest.

HISTORICAL TREASURE. Shell middens such as this one on Pockoy Island hold secrets about past civilizations, and archaeologists are racing to document as many as possible before rising sea levels inundate them. PHOTO/JOEY HOLLEMAN/S.C. SEA GRANT CONSORTIUM

A quick shovel test in 2017 found a type of pottery that indicated the site had been occupied about 4,000 years ago, Taylor says. More detailed transects every 33 feet confirmed a shell ring beneath the surface.

SCDNR, which manages the Botany Bay site, decided to schedule a dig. When Tropical Storm Irma’s surge ate away about 60 feet of Pockoy Island’s beach in September 2017, the dig took on new urgency.

“We’re trying to get this thing before the ocean does,” Taylor says while coordinating the dig in May 2018. “We’re about 60 feet closer to the ocean than we were a year ago.”

The shell ring, which had hidden under cotton fields in the 1800s and a maritime forest as the beach migrated inland in the late 1900s, could be washed away by the next strong storm surge.

Once shell rings fall to sea-level rise, “we don’t have the opportunity to learn about these people,” Taylor says.

The urgency holds true for hundreds of known archaeological sites. Tides already lap at the base of Fort Frederick, an 18th century British structure in Port Royal, South Carolina. Santa Elena, a National Historic Landmark and the site of a Spanish colony established in 1566, is barely above sea level. Fortunately, Santa Elena is on the U.S. Marine Corps training base at Parris Island, giving it an extra level of protection.

Pockoy Island, only a few feet above sea level and protected from waves by a small dune system, isn’t a site where major efforts will be made to protect the ring. So the only sensible step was to try to document the site, Taylor says.

The ring, clearly a human-built structure encircling an open shell-free plaza, is only about one to two feet high, not nearly as impressive size-wise as others nearby. But every one of these structures tells a little more of the story of the people who lived in the region 4,000 years ago – and each raises more questions, says Karen Smith, applied research division director at the S.C. Institute of Archaeology and Anthropology at the University of South Carolina. But this window on an ancient culture might not be available much longer because of sea-level rise.

“They were here for 4,000 years,” Smith says of the coastal shell middens. “And many of them are going to be gone in 40.”
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Last updated: 11/7/2018 2:21:22 PM


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