High-resolution record of the Matuyama–Brunhes transition constrains the age of Javanese Homo erectus in the Sangiran dome, Indonesia

A high-resolution paleomagnetic study at the Sangiran Early Man Site, Indonesia, has precisely dated the Matuyama–Brunhes (MB) transition, providing a crucial age constraint for Homo erectus fossils. The research identified a 7-meter-thick section marking the transition, characterized by three short reversal episodes and overlaid by a normal polarity magnetozone, which was fission-track dated to the Brunhes chron. This pattern matches records from Osaka Bay marine cores, confirming the MB boundary's age at approximately 776 ± 2 thousand years ago (ka). The study further correlated tuff layers in the Bapang Formation, revealing that the last occurrence of Homo erectus fossils and a tektite level coincide just below the Upper Middle Tuff, underlying the MB transition. This stratigraphic relationship aligns with deep-sea core data, indicating the meteorite impact preceded the MB reversal by about 12 ka. The findings establish the MB boundary as the uppermost horizon yielding Homo erectus fossils in Sangiran, refining our understanding of human evolution in Java.

Hyodo, M., Matsu’ura, S., Kamishima, Y., Kondo, M., Takeshita, Y., Kitaba, I., Danhara, T., Aziz, F., Kurniawan, I., & Kumai, H. (2011). High-resolution record of the Matuyama–Brunhes transition constrains the age of Javanese Homo erectus in the Sangiran dome, Indonesia. Proceedings of the National Academy of Sciences, 108(49), 19563–19568. https://doi.org/10.1073/pnas.1113106108