青藏高原邛多江盆地湖相沉积物总有机碳含量及其碳同位素特征的古气候意义  

PALEOCLIMATE SIGNIFICANCE OF ORGANIC CARBON AND ITS ISOTOPE FROM LACUSTRINE SEDIMENTS OF QIONGDUOJIANG BASIN IN SOUTHERN QINGHAI-TIBET PLATEAU

作　　者：杨珍[1] 杨文光[1] 朱利东[1] 李杜文 陶刚[1] 解龙[1] 李超[1] 和源[1] 刘和[1] YANG Zhen YANG Wenguang ZHU Lidong LI Duwen TAO Gang XIE Long LI Chao HE Yuan LIU He(Institute of Sedimentary Geology, Chengdu University of Technology Chendu 610059, China Fujian Institute of Geological Survey ,Fuzhou 350011,China)

机构地区：[1]成都理工大学沉积地质研究院,四川成都610059 [2]福建省地质测绘院,福建福州350011

出　　处：《矿物岩石》2017年第2期102-110,共9页Mineralogy and Petrology

基　　金：国家自然科学基金项目(41002055);教育部博士点基金(20125122110010);冈底斯-喜马拉雅铜矿资源基地调查项目(DD20160015)

摘　　要：选择青藏高原南部邛多江盆地湖相沉积物为研究对象,利用AMS^(14) C测年手段,建立邛多江盆地湖相沉积物40ka BP^30ka BP的时间序列。对采自5cm^250cm湖相沉积物中的50件样品进行总有机碳(TOC)含量、总氮(TN),TOC/TN比值和有机碳同位素(δ^(13) C)等环境代用指标的测试分析,将邛多江盆地40ka BP^30ka BP期间的古气候划分为如下几个阶段:气候暖湿期(40.2ka BP^38.5ka BP)、气候温干期(38.5ka BP^35.4ka BP)、气候过渡期(35.4ka BP^32.4ka BP)、气候动荡期(32.4ka BP^31.7ka BP)和气候转干期(31.7ka BP^30.3ka BP);经频谱分析表明,研究区存在1 552a,1 187a,961a,602a,538a和492a气候变化的准周期,千年尺度的气候变化可能与太阳活动、大气环流、大洋内部不稳定因素的影响及季风的活动周期有关,识别出的538a周期与太阳活动的530a周期相对应,可能表明太阳活动也是影响藏南邛多江盆地气候变化的原因之一。The lacustrine sediments of Qiongduo Basin in the southern Qinghai-Tibet Plateau are studied by using AMS14C dating method,and the time series of 40 ka BP-30 ka BP of Qiongduo- jiang basin sediments is obtained. The TOC content, TN, the TOC/TN ratio and δ13 Corg substi- tute indexes from 50 samples of 5 cm-250 cm Qiongduoliang Basin lacustrine sediments are analyzed,and the paleoclimate change of 40 ka BP-30 ka BP in Qiongduojiang Basin is divided into several stages： the warm humid climate period （40.2 ka BP-38.5 ka BP） ,the warm arid climate period （38.5 ka BP-35.4 ka BP）, the transition climate period （35.4 ka BP-32.4 ka BP） ,the volatility climate period （32.4 ka BP^31.7 ka BP） and shift to arid climate period （31.7 ka BP- 30.3 ka BP）. Spectrum analysis reveals that there are quasi-periodic climate variations of 1 552 a, 1 187 a,961 a,602 a, 538 a and 492 a from 40 ka BP-30 ka BP. Climate change at the millennium scale may be related to the effects of solar activity, atmospheric circulation, oceanic internal instability and monsoon activity. The identified 538 a cycle corresponds to the 530 a cycles of the solar activity, and therefore,the solar activity is also one of the causes of climate change in the Qong- duojiang basin.

关 键 词：青藏高原 邛多江盆地 湖相沉积物 有机碳同位素 古气候 

分 类 号：P597.2[天文地球—地球化学]