MIAMI (AP) _ A stone circle unearthed at the mouth of the Miami River may mark a place where people gathered hundreds of years ago to exchange goods and build arts and crafts, geologists say.

University of Miami scientists, after four months of investigation, recently determined the origin of two palm-sized primitive stone axes found at the site.

Geologists believe they were produced hundreds of years ago by people who lived 530 miles away in central Georgia.

Experts say the evidence shows ancient South Floridians maintained robust trade and cultural links with distant tribes.

``Rocks can't fly. The axes had to be traded here from outside the state,'' Christopher Eck, director of the Miami-Dade Division of Historic Preservation, said in Thursday's Miami Herald.

Geologists determined that the axes were not produced locally because the tools were made from basalt, a hard, volcanic rock not found in Florida. Researchers said they were able to pinpoint the origin of the axes to within a few hundred miles.

The site, known as the Miami Circle, was discovered last year.

A developer had planned to build a $126 million apartment complex at the location. But a circuit judge ruled last June that the county can take the land.

A jury trial, planned for October, will determine how much the county would have to reimburse developer Michael Baumann for the 2.2-acre property.