Louisiana State University

LSU Campus Mounds: The Oldest Known Man-made Structures in North America

LSU Department of Geology & Geophysics Centennial & Endowed Seminar

Brooks Ellwood, professor emeritus in the department of geology & geophysics will present his research on the campus mounds. 

Radiocarbon dating of the two LSU Campus Mounds indicates that their construction began about 11,000 years ago, making the LSU Campus Mounds the oldest known and intact Man-made structures in the Americas. The age analyses presented here are based on 3114C dates. The older and deeper parts of the LSU Campus Mounds contain many thin, burned ash lenses, suggesting that the LSU Campus Mounds may have been used for ceremonial or cremation purposes. The ash layers also contain microscopic fragments of burned, large mammal osteons or bone. It appears that construction of Mound B began during the climate amelioration that followed the Younger Dryas climate event, which ended at ~11,700 BP, followed by a hiatus in the building of the LSU Campus Mounds when climate deteriorated later, during the 8200 Climate Event which defined the end of the Holocene Greenlandian Stage and the beginning of the Northgrippian Stage.


Friday, August 26, 2022 at 3:30pm to 4:30pm

Energy, Coast & Environment Building, Dalton Woods Auditorium