Carbon dating of charcoal found at the Keezhadi excavation site in Sivaganga district has established that the settlement there belonged to 200 BC, according to K. Amarnath Ramakrishna, Superintending Archaeologist (Excavation Branch,Bengaluru).
The excavations have thus proved that urban civilisation had existed in Tamil Nadu since Sangam age. “So far there has been an impression that urban civilisation did not exist in Tamil Nadu. The excavations and carbon dating have disproved the opinion,” said Mr. Ramakrishna, who is heading the excavation project in Keezhadi.
Carbon dating was done at Beta Analysis, a Florida-based laboratory and the report was received in the first week of February.
“It is one of the top ranking laboratories in the world and is rated on a par with Arizona Radiocarbon Dating Lab. We sent only two samples and the report has been sent to the Archaeological Survey of India (ASI). We still have kept 20 more samples for carbon dating,” Mr. Ramakrishna told The Hindu on Tuesday. Carbon dating of a single sample costs ₹50,000.
Charcoals were found in stratigraphical layers at the excavation site at Keezhadi. “Even though small excavations were done around 150 places in Tamil Nadu we could not find charcoal in those sites. The presence of carbon in organic material helps establish accurate date as it normally exists for 5,560 years,” he said.
Mr. Ramakrishna added that a clear picture of the civilisation would emerge only if carbon dating of charcoal found in various stratigraphical layers are tested. Archaeologists have found 5,800 artefacts in Keezhadi after two years of digging. On Monday the Centre had granted permission for further excavations.