Funds are requested to support two years of research on late Neogene terrestrial Paleoclimatology, zoogeography, and biochronology of Asia. Pertinent data are available for the Siwalik group of southern Asia (Pakistan), and indicate important paleoenvironmental changes through time, reflecting in part, the development of monsoons. We propose to develop a second data source in the Yushe Basin, Shanxi, PRC, the longest (late Miocene through early Pleistocene) sequence of fossiliferous Neogene strata known in eastern Asia. Detailed knowledge of the faunal history of Yushe Basin, coupled with a precise chronology based on paleomagnetic reversal stratigraphy, will contribute to reconstructing Asian terrestrial paleoclimatology. By reference to sequences from Pakistan and the Miocene oceans, our results will show which terrestrial climatologic trends were local, and which may have been worldwide in scope. Development of the vertebrate fossil record of the Yushe Basin will provide information on mammalian paleobiogeography, with particular relevance to interchange events with North America. Documentation of East Asian faunal succession will also provide the biostratigraphic basis necessary to define Asian provincial mammal ages. The proposed research is a joint project with Chinese colleagues at the IVPP, Beijing, and our institutions jointly contain major unstudied fossil collections from Yushe Basin. This proposal is specifically concerned with augmenting the collections of micromammals, and constructing a precise magnetochronology, as a contribution of data necessary for paleoclimatologic, paleobiogeographic, and biochronologic syntheses.