摘要
高湖面是湖泊演化的鼎盛期,指示区域的温暖湿润气候。关于青藏高原湖泊高湖面的年代有不同的观点。一种观点(主要是基于14C测年)认为在氧同位素三阶段晚期青藏高原普遍存在"大湖期"或"泛湖期",并且其温度和降水可能比全新世还高。另一种观点(主要基于释光、铀系测年等)认为青藏高原湖泊的最高古湖面出现在氧同位素五阶段,之后湖面逐渐下降。柴达木盆地位于青藏高原的东北部,其高湖面年代的研究可为认识青藏高原环境演化提供基础资料。本文选择柴达木盆地东部的托素湖和尕海湖高出现代湖面的湖相沉积和湖岸砂堤为研究对象,利用石英光释光测年方法建立其年代序列。根据沉积物沉积特征和光释光年代结果认为,尕海湖和托素湖古高湖面出现在82~73ka、63~55ka、34.4ka和全新世早期。通过与青藏高原及周边湖泊高湖面年代记录对比,认为尕海湖和托素湖的最高湖面主体出现在氧同位素五阶段,之后湖面逐渐下降。
High lake levels of terminal lakes indicate warm and humid climatic conditions.Controversial views exist regarding the ages of high lake levels on the Qinghai-Tibetan Plateau.One view(mainly based on 14C dating)proposes that the pan-lake period(40~28 ka BP)or great lake period(40~25 ka BP)generally existed in the late part of the Marine Isotope Stage(MIS)3,during which the temperatures and precipitation were probably much higher than those in the Holocene.However,another view(mainly based on Optically Stimulated Luminescence(OSL)and U-series dating)argues that the highest lake level of paleolakes on the Qinghai-Tibet Plateau occurred in MIS 5 and later lowered gradually.Gahai Lake and Toson Lake are located in the eastern Qaidam Basin,northeastern Qinghai-Tibet Plateau.Here we report quartz OSL age estimates of highstand lacustrine sediments and beach deposits to establish the lake level history for the two lakes.The results imply that the high lake stands existed at 82~73 ka,63~55 ka,34.4 ka and early Holocene(11~9 ka),and that the highest lake level occurred in MIS 5 in the Late Quaternary.
作者
樊启顺
赖忠平
刘向军
孙永娟
隆浩
FAN Qishun;LAI Zhongping;LIU Xiangjun;SUN Yongjuan;LONG Hao(Key Laboratory of Salt Lake Resource and Chemistry,Qinghai Institute of Salt Lakes,Chinese Academyof Sciences,Xining,810008;Graduate University of Chinese Academy of Sciences,Beijing,100049)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2010年第11期1652-1660,共9页
Acta Geologica Sinica
基金
国家自然科学基金项目(编号40872119
41002060)
中科院"百人计划"项目(编号A0961)资助的成果
