jueves, 7 de febrero de 2013

Little Salt Spring excavation has given glimpse of past

By KEITH MORELLI
TAMPA --
Five hundred years after Ponce de León landed near St. Augustine and named the land La Florida — celebrated this year with more than 100 historical commemorations and events — the state's main porthole into its distant past is being closed.

Little Salt Spring in Sarasota County has yielded more artifacts that shed light on the first occupiers in Florida than virtually any other archaeological site in the state. The artifacts gleaned from the spring in the past 21 years have given scientists a glimpse into what it was like to live here even before the first pyramids appeared in Egypt and ages before de León named the state.

That effort is ending. Scientific divers made their last foray into the dark depths three weeks ago after the University of Miami's Rosensteil School of Marine & Atmospheric Science, the owner of the site, announced the research facility was closing down because of shrinking budgets.

The North Port sinkhole was an oasis in a semi-arid landscape 12,000 years ago, drawing prehistoric people from all around — people who predated the Calusa, Tocobaga and Timucuan tribes — people who left behind scant evidence of their existence. Nothing much survives a dozen millennia. Wood rots, bones become dust.

Archaeologists say the pieces of wood and fragments of bone collected from Little Salt Spring are among the most revealing and intriguing evidence left behind by the Paleo and Archaic period Indians who roamed the land alongside woolly mammoths and giant ground sloths.

John A. Gifford is the Rosensteil School professor of archaeology who has been in charge of digs and dives at the 111-acre Little Salt Spring site since 1992.

"It's money," Gifford said. "My understanding is that the new dean here, after evaluating Little Salt Spring, decided he didn't want to spend the $100,000 a year to maintain it. That's basic maintenance and the cost of a caretaker."

The cost of the dives doesn't come out of that budget, he said. Archaeological dives are funded through small grants from the state or from private donors such as National Geographic or the Smithsonian Institute.

Attempts to reach the Rosensteil School for comment were unsuccessful.

The closure of Little Salt Spring means the end of Gifford's association with the Rosensteil School.

"I had planned on doing three more years," he said, "but because of this, I'm retiring after this semester. The reason I was hired in 1983 was to work at Little Salt Spring. My job was to do underwater research in Little Salt Spring.

"I basically bet my career on the potential for that site producing significant artifacts," he said.

Even though lots of work there remains to be done, he is not disappointed in what was accomplished.

"I have no regrets," he said. In the past two decades, less than 5 percent of what lies in the spring has been recovered, he said. But, he said, the artifacts that were found, including wooden tools and weapons and bones, have been important.

One significant find was a deer antler that had 28 parallel marks on it, like a ruler, he said.

"It obviously was artificially put there by somebody who wanted to keep track of time," he said, "since there are 28 days in a lunar month." He estimates the antler is 10,000 years old.

So much remains submerged, he said, that a clear and complete picture of the civilization that lived then remains elusive.

"We have a really, really small sample," he said. "In the whole upper basin area, we have excavated only 3 or 4 percent of the total area, which is not really much of a sample. What we can say for sure is that we have a lot of debris on that slope."

If you could look at the sinkhole from the side, you would see an hourglass, with the surface and bottom about the same diameter and a narrow middle about a third of the way down. The bulging sides form sloped ledges that contain a treasure trove of artifacts.

Gifford said that 10,000 years ago the water level was probably 45 feet lower and the bulging underwater slope likely was the shoreline, where people gathered.

"There are all kinds of possibilities of what people were doing there," he said. "They were using it as freshwater source, and also possibly as some sort of trap. They were driving animals like deer over a blind and into the water, drowning them and pulling them out."

Bones of animals show signs they were butchered on the shore, he said.

Originally, people in southern Sarasota County thought Little Salt Spring was nothing more than a shallow freshwater pond with a tinge of salinity. But, about 60 years ago, scuba diver Bill Royal of Nokomis found the spring was more than 200 feet deep and extended well into the Floridan Aquifer.

In the 1970s, divers began finding well-preserved wood artifacts ranging from 7,000 to 12,000 years old. Many of the findings were mysteries. There were no other examples known for comparisons.

One artifact, for example, was a 9,500-year-old boomerang found near fossils, including an extinct tortoise. There were bones of a mastodon and a giant ground sloth.

Little Salt Spring was donated to the University of Miami in 1982. Gifford and other scientists have been exploring the depths since 1992, when the science of diving for prehistoric artifacts was in its infancy.

"I did my first dive in the summer of 1992," Gifford said. Since then, "We dove three or four times a year, whenever I could get away from teaching."

The site is unique, though there are dozens of other important sites around La Florida that offer glimpses of what it was like here long before the state became known by that name.

"Florida has more of these wet sites than any other part of the United States," Gifford said.

Saltwater bogs in Marco Island and near Titusville are two important ones. There, archaeologists had to dig through the muck around mangroves to unearth artifacts. But neither is like Little Salt Spring, the preserved relics of which continue to wait to be discovered and pulled up from the depths.

"Little Salt Spring," Gifford said, "has the potential of producing hundreds and hundreds of artifacts."

The shuttering of Little Salt Spring was news that rippled through the scientific community in Florida.

"It's always unfortunate whenever any archaeological site that has this kind of potential is shut down," said Brent Weisman, an anthropology professor with the University of South Florida. "It's closing a research window that could inform the public about the lives of the people who were first in Florida."

Precious little is known about the first human occupiers in Florida, he said, and Little Salt Spring is like a spotlight on that primitive civilization.

"It's a rare site," he said. "It is one of Florida's most puzzling and enigmatic archaeological sites. It is significant, based on what has been found there; the rich archaeological evidence of the earliest period of human occupation in Florida. It's a time period of which we know very little."

Archaeologists typically find stone tools of past civilizations that lived here 10,000 to 12,000 years ago, but the wooden and organic tools and weapons that are coming out of Little Salt Spring make the site significant, he said. "It's rare to have something that is not made of stone," he said.

What makes the underwater artifact depository unique is the water. It's anoxic, which means no microbes or bacteria can live there, greatly reducing the decomposition of organic material. Wooden tools as well as animals' soft tissues and bones are preserved nearly intact.

"That makes it globally significant," Weisman said. "It doesn't appear anywhere else. It is one of Florida's points of light."

Based on the limited-but-important finds at Little Salt Spring, Weisman concluded that Florida's first residents "had a very well developed technology, and they took full advantage of the natural resources of their environment. The more we learn about them, the more impressed we are with their technology."

They had some sort of religion, he said, based on what has been found in burial mounds discovered up and down Florida's Gulf Coast. "There was nothing primitive about them as human beings," he said.

Florida was unrecognizable 10,000 years ago, he said. The sea level was 50 feet lower, the land mass was much larger. The climate was semi-arid, not sub-tropical as it is now.

 "And," Weisman said, "there were gigantic animals walking around, animals that are now extinct. It was a different world."


 http://www2.tbo.com/news/breaking-news/2013/feb/03/little-salt-spring-excavation-has-given-glimpse-of-ar-623732/

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