川西阿坝盆地南缘阿柯河Ⅲ级阶地晚更新世中期的孢粉记录  

Middle Late-Pleistocene Sporopollen Records of Ake River III Terrace in Southern Margin of Aba Basin,Western Sichuan

作　　者：祝婷 何政伟[1] 杨振京[2,3] 康桂川 管森森 朱昱汀 ZHU Ting;HE Zhengwei;YANG Zhenjing;KANG Guichuan;GUAN Sensen;ZHU Yuting(College of Earth Sciences,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang,Hebei 050061,China;Key Laboratory of Quaternary Geochronology and Hydrologic Environment Evolution,China Geological Survey,Shijiazhuang,Hebei 050061,China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]中国地质科学院水文地质环境地质研究所,河北石家庄050061 [3]中国地质调查局第四纪年代学与水文环境演变重点实验室,河北石家庄050061

出　　处：《现代地质》2023年第4期870-880,共11页Geoscience

基　　金：四川省地震局项目“阿坝县1∶1万城市活动断层探查”(5132292018000310)。

摘　　要：植被的生长变化指示气候的演化,本文利用孢粉记录反演古植被,重建古气候。选取青藏高原东部的川西阿坝盆地南缘阿柯河Ⅲ级阶地PM01剖面为研究对象,进行样品的孢粉分析和光释光(OSL)测年,以分析阿坝盆地的气候演化。测年结果显示剖面PM01的年龄为晚更新世中期(78.4±7.1)~(71.6±6.2)ka B.P.。根据孢粉组合特征和数学分析方法,将剖面PM01划分为3个孢粉组合带,结果表明阿坝盆地在晚更新世中期(78.4±7.1)~(71.6±6.2)ka B.P.的植被为疏林草原。古气候演化过程可分为三个阶段,第一阶段的气候表现为寒冷干旱;第二阶段较第一阶段温暖,但依然表现为寒冷偏干;第三阶段趋向更温暖,表现为温凉偏干。该结果与末次冰期的气候变化趋势一致。本研究为川西地区第四纪植被与气候演化研究提供了新资料,对青藏高原东部第四纪古气候的研究具有参考意义。Vegetation growth and change have important implications for climatic evolution.In this study,we used sporopollen record to reconstruct paleovegetation and paleoclimate.Based on the sporopollen study of the Ake River III-level terrace in the southern margin of Aba basin in western Sichuan(eastern Qinghai-Tibet Plateau)and OSL dating,the results show that PM01 is(78.4±7.1)to(71.6±6.2)ka B.P.(middle Late Pleistocene).According to the palynological assemblage and mathematical analysis,the PM01 profile was divided into three palynological zones.The results show that vegetation in the Aba Basin was sparse forest and grassland from(78.4±7.1)to(71.6±6.2)ka B.P.in the middle Late Pleistocene.The paleoclimate evolution can be divided into three stages:(1)cold and arid;(2)warmer than the first stage,but still cold and dry;(3)warmer and then cooler and drier.The results are consistent with the climate evolution trend of the last ice age,and provide new data for the study of the Quaternary regional vegetation and climate evolution,which is of great significance for studying Quaternary paleoclimate in the eastern Qinghai-Tibetan Plateau.

关 键 词：孢粉 川西地区 Ⅲ级阶地 古气候 

分 类 号：P534.63[天文地球—第四纪地质学] Q914[天文地球—古生物学与地层学]