长江三角洲东缘地区全新世孢粉与古环境研究

通过对长江三角洲东缘地区南汇鹤鸣孔、东海1井、高桥G2孔3口钻井全新世地层的孢粉研究，划分出了5个孢粉组合带和3个亚带，恢复了本地区植被演替、气候波动的5个阶段：第1阶段为针阔叶混交林一草地，反映气候温凉略湿（前北方期）；第2阶段为含常绿阔叶树的针阔叶混交林，反映气候温和略干（北方期）；第3阶段为以常绿栎类、栲属、杨梅等为主的常绿阔叶林，反映气候热暖潮湿（大西洋期）；第4阶段是以栎、松、禾本科为主的针阔叶混交林，反映气候温暖略干（亚北方期）；第5阶段是以落叶栎类、常绿栎类、松为主的落叶阔叶、常绿阔叶、针叶混交林一草地，反映气候温暖湿润（亚大西洋期）。这种气候波动与世界性气候变化相一致，为本地区的地层年代划分和对比提供了可靠的证据，为全新世古植被、古气候、古环境的重建提供了重要的孢粉学资料。

Studies on sporo- pollen and paleoenvironment of Holocene in the East edge of Changjiang River Delta

Through intensive study on pollen and spores from the cores of Hm, Dh1 and G2 at the east edge of Changjiang River delta, Five palynological assemblages and three sub - assemblages were distinguished. There are Five stages about the evolution of vegetation and climate which were reconstructed for the Holocene on this area as follows:mixed forest of conifers and broad - leave trees-grassland, reflecting a temperate and little wet climate (sub - arctic period) ; mixed forest of conifers and broad - leave trees with a few evergreen broad -leave trees, reflecting a temperate and little dry climate (Boreal period) ; evergreen broad - leave forest being mainly composed of Quercus (evergreen) and Castanopsis indicating a hot and moist climate (Atlantic period) ; mixed forest of conifers and broad - leave trees, indicated by Quercus, Pinus and Gramineae as main element in palyno-logical assemblages, reflecting a warm and little dry climate (Sub - Boreal period); mixed forest of deciduous broad - leaves, evergreen broad - leaves and conifers, Quercus ( deciduous, evergreen) and pines, being the main components, reflecting a warm and wet climate (Sub - Atlantic period). These fluctuations coincide with the global climatic changes. The study provides reliable evidence for the division and comparation of the age of the sediment at this region, also for the biostratigraphy and reconstructions of paleovegetaton, paleoclimate and paleoenvir-onment in this area since the Holocene.