UNIVERSITY PARK, PENNSYLVANIA—According to a statement released by Penn State, Dylan S. Davis and his colleagues identified possible shell rings and mounds using deep machine learning to analyze data collected from lidar surveys, synthetic aperture radar, and multispectral satellite imagery of a 4,000-square-mile area of the southeastern coast of the United States. These technologies detect structures underneath heavy forest or ground cover, provide information on soil attributes, and reveal features not visible to the human eye. Such shell rings were constructed between 3,000 and 5,000 years ago, and are thought to have been used as trade centers, Davis said, since copper from the Great Lakes region and imported ceramics and lithics have previously been recovered from the 50 known shell ring sites in the region. The study spotted hundreds of potential new shell ring sites, based upon their slope and elevation change when compared to the surrounding landscape. Some of these sites were found in counties where shell rings have never been identified. Davis said the team has not yet been able to investigate the possible shell rings in person. To read about rituals performed at Georgia's Dyar Mound, go to "Enduring Rites of the Mound Builders," one of ARCHAEOLOGY's Top 10 Discoveries of 2020.