Magnetostratigraphy of Plio-Pleistocene fossiliferous cave sediments in the Bubing Basin, southern China

Our understanding of the chronological sequence of Pleistocene land mammal faunas (including hominids) preserved in caves and fissures in the karstic terrain of subtropical southern China has been greatly impeded by the discontinuous nature of the strata yielding the fossils. A contributory issue is the lack of suitable elements for numerical dating, especially for the Early Pleistocene cave sediments. Here we present new magnetostratigraphic dating results for five cave sedimentary sequences in the Bubing Basin, Guangxi Zhuang Autonomous Region, which contain the typical Pleistocene Gigantopithecus fauna and Ailuropoda-Stegodon fauna of southern China. The five karstic caves are situated at elevations ranging from 252 m to 191 m above sea level. The integrated dating results reveal that the five cave sedimentary sequences span an age range from the late Gauss normal Chron to the early Brunhes normal Chron. The faunas are assigned to >2.6 Ma (Mohui-houshan Cave), 1.95-1.78 Ma (Mohui Cave), 0.99-0.78 Ma (Baolai Cave) and ∼0.7 Ma (Upper Wuyun and Ganxian Caves). Furthermore, by combining our new magnetostratigraphy work with previously published magnetostratigraphic, U-series and electron spin resonance dating results, a chronological sequence of the Plio-Pleistocene mammalian faunas from cave sites in southern China has been established. The chronological sequence contributes to an improved understanding of the evolutionary processes of Plio-Pleistocene land mammals, as well as of early humans in subtropical southern China.