| Abstract: |
The fossils described above are not archaic taxa and are all recent species. Because the geographic position of Lijiang approaches the subtropical regions, the presence of rhinoceros does not indicate a large climatic fluctuation or more archaic time period. The fossil-producing horizon is uncemented and lightly consolidated, substantiating its age to be younger than Middle Quaternary. But because of the degree of fossilization, the sediments cannot be Holocene in age. Moreover, as indicated above, the fluviolacustrine deposits that have been truncated by the Yanggongjiang River illustrate orogenic activity, and consequently the sediments constituting both banks of the Yanggongjiang River and the fossils recovered from the vicinity of Mujiangqiao Village were initially regarded as Late Quaternary (Q3). Sedimentary perspectives from other workers suggest that the western sandy gravels are comparatively older, while the eastern fine sands are younger or may be Q2 3 . Further advanced determinations of geologic age must await larger-scaled excavations and more fossil discoveries. Glacial effects also bear upon the age of the fossil deposits in the Lijiang region. In the summer of 1956 the University of Yunnan organized a field expedition to conduct observations in the glacial regions of the Yulongshan Mountains, on the northwest border of the Lijiang Basin. According to the data of Ren et al. (1957)* these mountains have undergone three successive glacial stages, including one in the Holocene. From oldest to youngest these stages are recognized as Lijiang Glacial, Dali Glacial, and Holocene Glacial. The lowest descent of ice flow was to the 2,800 m level during the Lijiang Glacial Stage, which Ren et al. believed to probably be Middle Pleistocene (Q2). This text concurs with Ren et al. After the Lijiang Stage the ice gradually retreated to higher levels and became restricted to mountain peaks with the result of an absence of interglacial sedimentation. This represented a third glacial retreat and is completely consistent with the results of research conducted within the basin. From the Middle Pleistocene onward a gradual warming occurred within the Lijiang Basin which signified the initiation of the Late Pleistocene (Q3). The climate was tropical, resulting in the success of subtropical large mammals including rhinoceros and water buffalo. It was at this time that hominids entered the Lijiang Basin for habitation.
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