October 21, 2022
Two grassy mounds located at Louisiana State University containing thousands of charred mammoth bones and with a cosmic alignment of both mounds towards a star are among 800 mounds of this type in Louisiana
Sediment cores have been taken from the two mounds and they found layers of burned ash from reed and cane plants and burned bone fragments in the cores. Radiocarbon dating show that the mounds were built 11,000 years ago, and built up over thousands of years. The 11,000 years ago date places these mounds as the oldest ever built in North America.
8,200 years ago, the earlier southern mound was abandoned in a cold period in the Northern hemisphere which lasted 150 years. 7,500 years ago they built a second mound and reworked the abandoned mound 6,000 years ago. The mounds were aligned with the giant star Arcturus.
The research is published in the American Journal of Science by Yale University.
More information: Brooks B. Ellwood et al, The LSU campus mounds, with construction beginning at ∼11,000 BP, are the oldest known extant man-made structures in the Americas
American Journal of Science (2022). DOI: 10.2475/06.2022.02
PhysOrg has the report here: