长江三角洲古河谷区冰后期孢粉组合及古气候意义

The Sporo Pollen Assemblage from Postglacial Period in the Paleo-incised Valley of the Yangtze River Delta and Its Palaeoclimate Significance

依据长江三角洲古河谷区典型钻孔CSJA6孔中冰后期孢粉分布情况,结合有孔虫分析以及6个样品的AMS^(14)C年龄,自下而上初步建立了冰后期3个有时间标定的孢粉组合,分别为:Ⅰ.Quercus-Lipuidambar-Artemisia-Polypodiacea组合,时代属于早全新世;Ⅱ.Quercus-Castanopsis-Cyperaceae-Pteris组合,时代属于早-中全新世;Ⅲ.Quercus-Ulmus-Artemisia-Polypodiacea组合,时代属于中-晚全新世。3个孢粉组合带所反映的古气候演变过程为凉干—热湿—温干,这与中国的气候大环境较为一致,且与本区前人研究成果亦做了相应的对比,依然具有较好的可对比性。

According to the postglacial sporo-pollen distribution from the typical borehole CSJA6 in the paleo - incised valley of the Yangtze River Delta, combining with the forams analysis and AMS ^14 C dating of 6 samples, 3 sporo-pollen assemblages with time calibration from below were established： Ⅰ. Quercus-Lipuidambar-Artemisia- Polypodiaeea assemblage, belonging to the early Holocene; Ⅱ. Quercus-Castanopsis-Cyperaceae-Pteris assemblage, belonging to the early-middle Holoeene;Ⅲ. Quercus-Ulmus-Artemisia-Polypodiaeea assemblage, belonging to the middle-late Holocene. These three sporo pollen assemblages reflect the paleoelimate evolution process as cold and dry-hot and wet-warm and dry, which is consistent with the climate environment of China. This research is basically identical with the results of previous studies in this region.