The Youganwo Formation is a geologic formation in Guangdong, southern China. The Youganwo Formation preserves fossils dating back to the Middle or Late Eocene epoch of the Paleogene period.
The Youganwo Formation is part of the Maoming Basin, a structural basin in Guangdong, China that preserves sediments that range in age from the Late Cretaceous to the Neogene period.[1] The upper part of the Youganwo Formation, which consists of dark brown oil shales, is the only stratigraphic unit in the Maoming Basin where vertebrate fossils have been found.[2] The dark brown oil shales that make up the formation were deposited in lacustrine conditions.[2] Analysis of fossil leaves found in the formation indicate that the climate was similar to the modern-day climate in Guangdong, with humid and subtropical conditions, hot summers, warm winters, and increasingly seasonal rainfall.[3]
The Youganwo Formation has been dated to the middle-late or Late Eocene.[2] The stratigraphy of the formation and the fossil plants found indicates a Middle Eocene age, whereas fossil pollen suggests Late Eocene. This may be due to fossil samples used; it is possible that the upper parts of the formation are Late Eocene and that the lower parts are Middle Eocene.[1]
↑Herman, A. B.; Spicer, R. A.; Aleksandrova, G. N.; Yang, J.; Kodrul, T. M.; Maslova, N. P.; Spicer, T.E.V.; Chen, G.; Jin, J.-H. (2017). "Eocene–early Oligocene climate and vegetation change in southern China: Evidence from the Maoming Basin". Palaeogeography, Palaeoclimatology, Palaeoecology. 479: 126–137. Bibcode:2017PPP...479..126H. doi:10.1016/j.palaeo.2017.04.023.
