柴达木盆地大浪滩130ka BP以来的孢粉组合与古气候  

Sporo-pollen assemblage and palaeoenvironment since 130ka BP in Dalangtan Lake of Qaidam Basin

作　　者：侯献华[1,2,3] 郑绵平[1,2,3] 杨振京[4] 杨庆华[4] 毕志伟[4] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质科学院盐湖与热水资源研究发展中心,北京100037 [3]国土资源部盐湖资源与环境重点实验室,北京100037 [4]中国地质科学院水文地质环境地质研究所,河北石家庄050061

出　　处：《干旱区地理》2011年第2期243-251,共9页Arid Land Geography

基　　金：矿产资源研究所基本科研业务费项目(K0915);地质调查项目(编号:1212011018004);国家自然科学基金项目(40972212)共同资助

摘　　要：应用柴达盆地西部大浪滩梁ZK02孔岩芯,依据铀系年龄数据,选择130 ka BP(90.5 m以上)的含石膏粉砂淤泥层中34个样品进行孢粉分析研究,依据其孢粉组合特征,将该孔深90.5m以浅的孢粉百分比图式从下至上划分6个区域性孢粉带,进而分析了该区末次间冰期(130 ka BP)以来的古植被状况,结果表明,山地主要由松、云杉、冷杉等组成的寒温性针叶林覆盖,而盆地则主要是以蒿、菊、禾本科等中旱生草本植物组成的温性草原,总体上反映了该区130 ka以来代表冷干气候的5次成盐期及其所夹的6次温湿期变化韵律,由此可以推测,该区主要植被和古环境的进程很可能源于东亚夏季风的减弱或增强,其气候旋廻大致可以和青海湖QH-86孢粉分析所揭示的130 ka以来古植被演替及深海氧同位素第三阶段乃至黄土磁化率所反映的6个夏季风增强的时段进行对比。This paper obtained the data of the cores based on U-series age from ZK02 borehole at ridge of Dalangtan in the western Qaidam basin,where 34 samples from the sludge containing gypsum silt were selected of select for 130 ka BP(90.5 m and above) and the pollen analysis was done.Based on the pollen characteristics,the assemblage of the pollen from the bottom upwards can be divided into six zones to analyze the ancient vegetation succession in the last interglacial(130 ka BP) state in this area.The results showed as follows: in the period of 130 ka BP(the last interglacial period),the vegetation in the western Qaidam basin obviously changed compared with the very significant environment.Overall,the spruce,fir and pine trees consisted of some cold temperate coniferous forest had expanded for five times to the surrounded Zhongshan area,and even extends towards the basin.But the grass of Gramineae,Compositae,Artemisia as the main component occupied the basin,which showed the climate that was mild climate controlled by the summer monsoon flow from the East Asia to the West,while vegetation flourished,the enhanced soil expanded,water being desalinized,the lake larger in the interstadial period,particularly that in the first pollen assemblage I(130-92 ka BP) and the pollen assemblage IV(56.2-49 ka BP) in the duration of sedimentation when the plant diversity increased.In addition to the grassland vegetation in the basin,on the wetlands around the lake the plant was growing quite flourishing,which demonstrated that the two periods were the most enhanced summer monsoon circulation with more adequate rainfall and the forest expanding fast in the mountains.The river flow was incresing and salt lake became desaltinized.The emergent grasses were growing at the edge of the marsh in the lake area.In particular in 49 ka BP ago or so,coniferous forest was growing associated with mountain cedar.Thus it suggested that the place was affected by the southwest moist flow,which made the flora of Himalayan cedar grow in the mountainous ar

关 键 词：孢粉分析 铀系测年 末次间冰期 古植被 古环境 柴达木盆地 

分 类 号：P532[天文地球—古生物学与地层学]