(CNN) -- A University of Florida archaeologist found centuries-old bones this week during a dig in northeastern Florida, authorities said.

The human remains, estimated to be between 500 and 700 years old, were found Monday during a excavation at Silver Glen Springs Recreation Area in Ocala National Forest, about 30 miles south of Palatka, according to Jenifer Lowe with the Marion County Sheriff's Office.

Asa Randall, a senior archaeologist with the University of Florida, based his estimate on the depth of the burial site and the type of soil in which the remains were found, Lowe told CNN.

"The limestone the bones were found in had been in place for at least 500 years," she said. The discovery site was 3 1/2 feet deep and 2 feet wide, she added.

Marion County deputies were called to the scene during Randall's precursory dig because he was required by law to report the discovery of human remains, Lowe said.

"[The bones] are just pieces of history," she said. "We closed the case by exception -- unless they find something suspicious, they'll notify us, but I doubt they will."

The bones will be held by the university, which will conduct tests to determine their age, Lowe said.

Randall could not immediately be reached for comment.