Miocene palynoflora from Shengxian Formation, Zhejiang Province, southeast China and its palaeovegetational and palaeoenvironmental implications

Abstract

The Neogene Shengxian Formation is a set of strata consisting of basaltic rocks with sedimentary layers distributing in eastern Zhejiang Province, southeast coastal of China. New sporopollen data from three profiles were discovered as two palynological assemblages were recognized, i.e., Quercus E.–Liquidambar–Carya assemblage and Quercus E.–Fagus–Artemisia assemblage. By compiling the published sporopollen data, a Miocene palynological succession was established, including the late Early–early Middle Miocene Quercus E.–Liquidambar–Carya assemblage, the late Middle–early Late Miocene Quercus E.–Pinus–(Poaceae)–Trapa assemblage and the late Late Miocene Quercus E.–Fagus–Artemisia assemblage. Combining with megafossil plant records, palaeovegetation and palaeoenvironment of this period were reconstructed. It reveals that the zonal vegetation during the depositional period was similar to its modern counterpart but with more distinct altitudinal zonality because of the occurrence of Larix. It's also evident that thermophilous arbors dominated the vegetation during the late Early–early Middle Miocene, and conifers increased and aquatic plants Trapa thrived during the late Middle–early Late Miocene, while forests shrunk and grassland expanded during the late Late Miocene. The Miocene palynological succession in this study was well corresponding to the global climate changes during this period.