DAVID NIELD
6 SEPTEMBER 2020

Modern-day drone sensors can sometimes detect what's invisible to the human eye, such as the remains of a historical city called Etzanoa or the 'Great Settlement' in the fields of Wichita, Kansas – remains that have been buried for hundreds of years.

Researchers think they've found what's known as a 'council circle' monument in Etzanoa, and while no one is quite sure exactly what these circles were used for, they would have been significant sites for the community of the time.

The circular ditch measures some 50 metres (164 feet) in diameter and is a couple of metres (6.6 feet) deep. It matches other uncovered earthworks in the area of a similar shape, and has been picked out of a survey site of about 18 hectares (44.5 acres).

"Our findings demonstrate that undiscovered monumental earthworks may still exist in the Great Plains," says anthropologist Jesse J. Casana, from Dartmouth College. "You just need a different archaeological approach to recognise them."

"Our results are promising in suggesting that there may be many other impressive archaeological features that have not yet been documented, if we look hard enough."

Key to the discovery was the thermal, near-infrared (NIR) and visible light imagery captured by the drones as they flew over the site. These measurements capture slight changes in the soil composition, temperature, and nearby vegetation caused by infilling.

More:
https://www.sciencealert.com/drone-survey-reveals-wichita-council-circle-monument-on-a-farm-in-kansas