An archaeological dig is wrapping up at the site of Nashville's future baseball park at Sulphur Dell, although experts said they would like to have more time to explore what they consider a significant find.
Dr. Kevin Smith, a professor at Middle Tennessee State University, wrote about the discoveries on a Facebook page of the Middle Cumberland Archeological Society.
Smith wrote that the excavation uncovered "important prehistoric features and artifacts."
Smith told Nashville television stations WSMV that archaeologists have found the first hard evidence that an ancient Native American city was most likely a major manufacturer and exporter of salt about 800 to 900 years ago.
Salt production during that time period, from about 1150 AD to perhaps 1250 AD, was an industry as important to the ancient city as the music industry is to Nashville now, he said.
Smith said early settlers had written about large pottery vessels left behind by Native Americans in what is now Nashville, but now the physical evidence has been uncovered.
"I've worked on these sites for 30 years now and have researched about 300 of these sites, and this is the first time I've been able to hold in my hands the real evidence and see it in the ground that they were devoting so much effort to this commodity," Smith said.
Photographs taken at the site show that giant pottery vessels were once used as salt pans. They evaporated or heated mineral water to extract the salt.
The ceramic salt pans also bear imprints of fabric, which will help uncover materials used by the culture that has long since disappeared.
The archaeological exploration won't last long. According to the mayor's office, it was scheduled to wrap up Tuesday.
If the archaeological dig were to continue, it could delay the opening of the ballpark, scheduled for the beginning of the season in 2015.
Smith said that he'd like to have a month to explore the site and bring in a team of volunteers, but he said the city is not obligated to do any archaeological research and he's happy to have had any access to the site.