This is a really cool article from my neck of the woods.


"NORTH PORT - Scientists have a good idea what Florida was like 12,000 years ago: It was hot and dry and twice as wide as it is now because the oceans were 400 feet lower than they are now. That would put the Gulf coast of Florida about 100 miles west of the current shoreline.


Turtles the size of beanbag chairs roamed the land, along with giant sloths, mastodons and saber-toothed tigers.


Humans?


Yes, scientists say. Nomadic peoples roamed, briefly settling in spots where food was plentiful and where fresh water, sparse as it was, could be found.


Little Salt Spring, which reaches more than 200 feet into the earth, was a hot spot back then, the Don Cesar of its time, a place where traveling prehistoric people gathered to spend time, hunt animals and feast and then move on. The lush, nearly undisturbed sinkhole now is a treasure trove of artifacts that has not yet begun to spill clues about life back when now-extinct animals outnumbered humans.


Secluded, surrounded by thick vegetation and patrolled by an 8-foot alligator and four or five of her offspring, Little Salt Spring this week is bubbling with activity. Divers from Miami and Tampa are plunging in, dropping some 90 feet, where the light of the sun fades to black and silt stirred by the slightest movement cuts visibility to a bare minimum.


The divers are on a mission. They’re looking for old stuff, stuff that is 100 to 120 centuries old. Animal bones. Fossilized plants. And maybe if they’re lucky, human remains or remnants of a long-dead culture.


Divers have been in the water every day for a week and a half and have turned up lots of interesting artifacts but, so far, nothing related to ancient humans.


The search continues until the end of July.


It was 33 years ago when divers brought up circumstantial evidence that humans were here in 10,000 B.C. a giant tortoise shell with what appeared to be a spear plunged into it said John Gifford, associate professor and archaeological diver with the University of Miami’s Rosenstiel School of Marine and Atmospheric Science.


For the past 30 years, there have been no archaeological dives to that depth at the sinkhole, he said.


It costs to mount such a project, he said. This dive is being funded by the National Geographic Society. There are two teams of divers, one from the University of Miami and the other from The Florida Aquarium in Tampa.


Divers are examining the underside of a ledge some 90 feet down, he said. That’s the level where they expect to find what was here 12,000 years ago. In shallower waters, they found 15 oak stakes pounded around the perimeter of the sinkhole. They date back some 9,500 years, Gifford said.


Ice age migratory people used Little Salt Spring for water and as a place to hunt and kill thirsty animals such as mastodons and giant ground sloths.


Those people left evidence they were here, evidence that just now is being uncovered.


"This," Gifford said of the spring, "is a real time capsule."


Ninety feet down there is little oxygen in the cold water and that tends to preserve organic material such as bones, wooden tools and weapons.


It’s scientifically significant stuff, he said.


"Here in Florida, people don’t appreciate the fact that we have a prehistory that goes back thousands and thousands of years," Gifford said.


Archaeologists long have treated Little Salt Spring as an untapped gold mine of ancient artifacts, and the isolated spot is considered "one of the most important archaeological sites in the state, and perhaps the nation, for its wealth of information about the first Floridians more than 12,000 years ago," say officials with The Florida Aquarium.


The water chemistry in the sinkhole and temperature have helped create a rare site where artifacts defy decomposition, they said.


Little Salt Spring was discovered to be an underwater archaeological site in the late 1950s.


Seventy-four-old George Guy used to teach diving classes in the sinkhole. He was watching from the shore as the archaeologists bobbed in the water this morning. He first donned fins and a tank and jumped in in 1966, he said. He lived in St. Louis at the time.


His dives only descended to depths of 40 or 50 feet, he said. He never knew what treasures lay beneath him. It was too deep.


But the spot was a favorite, he said. "I’ve enjoyed it so much, I decided to move here," he said. Now, he volunteers at the site.


The sinkhole was donated to the University of Miami in 1982.


In 2005, Gifford and some graduate students, diving at a shallower level, discovered two artifacts estimated to be about 7,000 years old, a greenstone pendant and a carved stone artifact that appears to be part of a spear-thrower.


Gifford said there likely are many artifacts yet to be discovered.


Emily Landis, program officer with the National Geographic Committee for Research and Exploration, said, "The research proposed by Dr. Gifford is critical to our understanding of the first Americans. In 1975, hints of a 12,000 B.C. occupation were found on the 27-meter ledge at Little Salt Spring. If these early occupation dates are confirmed by modern excavation and laboratory analytical techniques, it would make Little Salt Spring one of the oldest confirmed pre-Clovis sites in the Americas."


The dives are difficult and dangerous, said Casey Coy, dive safety officer with The Florida Aquarium, one of eight divers on the excursion.


"There is a lot of flock, a lot of organic material," he said. "It’s easy to disturb the stuff and limit visibility."


That, and the fact divers are in total darkness, makes it dangerous.


"You can become very disoriented," he said. Each diver had to complete a 100-hour course in scientific diving, he said.


Gifford said the dives are exciting but they are not walks in the park.


Once the divers pass the point where sunlight reaches, "the beams of our lights are all that we see," he said."