渤海西部海域晚更新世以来的孢粉组合及古环境变化

Pollen spore assemblages and induced palaeoenvironmental changes in the western Bohai Sea since Late Pleistocene

通过对渤海西部海区TJC孔55.34m以浅地层岩性、测年及孢粉分析等研究,发现该海域晚更新世MIS 5以来的孢粉组合呈现针叶-阔叶-草本规律的旋回性变化,此特征变化是植被-气候-海平面共同作用的结果,气候暖湿、干(凉)冷交替频繁,海平面波动显著。MIS 5e、MIS 5c、MIS 5a、MIS 3及MIS 1(中全新世)阶段气候温暖湿润,陆区则发育针阔叶混交林或落叶阔叶混交林植被,近岸分布有湖沼植被和盐生草地,整体属于高海平面时期的滨海或滨岸浅海环境。MIS 2冰盛期沉积较薄,MIS 5d、MIS 5b、MIS 4和MIS 2阶段,气候偏冷(凉),以草本蒿和藜为主,陆区发育森林草地或针阔叶混交林草地,海平面较低。

The comprehensive study of the upper 55.34 m of core TJC-1 taken from the western Bohai area on sediment lithology,multi-method dating and high resolution spore-pollen data suggests that the changes in pollen assemblage since late Pleistocene are resulted from the joint effects of vegetation,climate and sea-level changes.Conifers,broad-leaved trees and herbs show a regular and cyclic pattern of variation,which indicates a frequent alternation of warm-wet and cold（cool）dry climatic conditions,in addition to significant sea level fluctuation.During the periods of MIS5 e,MIS5 c,MIS5 a,MIS3 and MIS1（early-middle Holocene）,mixed coniferous or deciduous broad-leaved forest were developed in the surrounding upland,and lacustrine-halobiotic grass prevailed on the coastal lowland in warm-wet conditions,indicating a coastal or shallow sea environment.There is a thin layer of LGM deposits in MIS2.During the periods of MIS5 d,MIS5 b,MIS4,and MIS2,conifers prevailed on the upland,and Artemisia-Chenopodiaceae dominated herbs in the lowland area under a cold（cool）-dry climate and low sea level.