The Brenham impact event, 693-552 years ago (1329-1470 CE)

Abstract

More than 10,000 kg of pallasites, micrometeorites (< 4 mm), positive Ir and Pt anomalies, and ~ 80 ha of impact craters have been found across an ~ 800 ha strewn field on the late Holocene surface of Kiowa County, Kansas. A suite of six AMS radiocarbon ages demonstrate that a cosmic impact event occurred sometime between 693 and 552 years ago, 1329–1470 CE. This event is recorded in Native American oral histories and petroglyphs located near the strewn field. Hopewell artifacts in the Ohio River valley postdate the impact event by more than 1,000 years. The Brenham impact event increases our understanding of the occurrence and effect of cosmic events on humans.