Год издания: 2022

We present detailed rock magnetic and paleomagnetic data of the key Ust-Obor section in Transbaikalia (Buryatia, Russia). The section consists of two partsthe lower loamy sediment unit of Eopleistocene age and the upper sandy sediment unit of Neopleistocene age. The lower unit contains a stratotype fauna complex of Late Eopleistocene age. The paleomagnetic study presented herein reveals only normal polarities of natural remanent magnetization throughout the section. Paleomagnetic results appear at odds with paleontological data, which constrain the lower unit to Eopleistocene age and consequently to the reversed-polarity Matuyama chron. Rock magnetic and paleomagnetic data do not support a remagnetization hypothesis to explain this apparent contradiction. Conversely, the statistically similar rock magnetic and paleomagnetic data of the upper (Neopleistocene) and lower (Eopleistocene) units suggest a common depositional environment and thus a similar geological age. The preferred hypothesis explaining the observations calls for a re-deposition of the Late Eopleistocene Ust-Oborian fauna within younger Neopleistocene sediment.