东海北部陆缘地区全新世孢粉组合及其古环境演变

对东海北部陆缘地区NH 0504孔和东海Dh1井全新世地层的孢粉进行了研究,划分出5个孢粉组合带和2个亚带,恢复了该地区植被演替、气候波动和古环境演变的5个阶段,为该区的地层年代划分和对比提供了科学的证据,为全新世古植被、古气候和古环境的重建提供了重要的孢粉学资料。划分的5个阶段为:第1阶段为针阔叶混交林-草地,反映出当时的气候以温凉略湿为特征(前北方期);第2阶段为含常绿阔叶树的针阔叶混交林,反映出当时的气候以温和略干为特征(北方期);第3阶段为以常绿栎类和栲属等为主的常绿阔叶林,反映出当时气候以热暖潮湿为特征(大西洋期);第4阶段是以栎、松和禾本科为主的针阔叶混交林,反映出当时的气候以温暖略干为特征(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-草地,反映出当时的气候以温暖湿润为特征(亚大西洋期)。

Palanological assemblages and Holocene palaeoenvironmental evolution in the continental margin of the northern East China Sea

A high-resolution spore-pollen record from two boreholes(NH0504 and Dh1) at the continental margin of the northern East China Sea were analyzed,and five palynological assemblages and two sub-assemblages were distinguished.There are five stages about the evolution of vegetation,climate and paleoenvironment 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 kinds of evergreen broad-leave trees,reflecting a temperate and slightly 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 palynological assemblages,reflecting a warm and little dry climate(SubBoreal 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).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 paleoenvironment in this area since the Holocene.