Earliest direct evidence of monument building at the archaeological site of Nan Madol (Pohnpei, Micronesia) identified using230Th/U coral dating and geochemical sourcing of megalithic architectural stone

Research at Nan Madol, Pohnpei, reveals the earliest direct evidence of monumental architecture in Eastern Micronesia, dating its onset to AD 1180-1200. This groundbreaking finding was achieved through high-precision uranium-thorium (230Th/U) coral dating and geochemical sourcing of basalt used in construction. Nan Madol, an ancient administrative and mortuary center, features artificial islets and structures built with columnar basalt and coral, serving as the former capital of Pohnpei. The study suggests that monument building at Nan Madol predates similar developments across Oceania by several centuries (AD 1300-1600), highlighting its significance in prehistoric social transformations. Future research is encouraged to explore the causes behind these changes through more detailed data on monument construction.

McCoy, M. D., Alderson, H. A., Hemi, R., Cheng, H., & Edwards, R. L. (2016). Earliest direct evidence of monument building at the archaeological site of Nan Madol (Pohnpei, Micronesia) identified using²³⁰Th/U coral dating and geochemical sourcing of megalithic architectural stone. Quaternary Research, 86(3), 295–303. https://doi.org/10.1016/j.yqres.2016.08.002