青藏高原周缘始新世—渐新世气候转换期风化演变及其对全球及区域气候环境变化的响应  

The weathering evolution during the Eocene-Oligocene Transition in the surrounding regions of the Tibetan Plateau and its response to global and regional climate changes

作　　者：崔灏 韦刚健[1] CUI Hao;WEI Gangjian(State Key Laboratory of Deep Earth Processes and Resources,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院广州地球化学研究所深地过程与战略矿产资源全国重点实验室,广东广州510640 [2]中国科学院大学,北京100049

出　　处：《地学前缘》2025年第3期274-287,共14页Earth Science Frontiers

基　　金：国家重点研发计划项目(2022YFF0800501)。

摘　　要：始新世—渐新世的气候转型(Eocene-Oligocene Transition,EOT)是新生代时期最为显著的全球降温事件之一,标志着地球气候系统从“温室”向“冷室”模式的关键转变。虽然深海沉积物较为一致地记录了这一降温事件,但众多陆相沉积记录却显示不同区域的气候响应呈现出显著的空间差异,凸显了全球气候背景与区域环境相互作用的重要性。青藏高原隆升显著影响全球大陆风化的格局,与新生代全球气候变化有密切关系,因而高原周缘的大陆风化演变是反映全球与区域气候变化的良好指示。本文汇总了晚始新世—渐新世青藏高原周缘大陆风化的演变记录,结合我们在青藏高原东南缘吕合盆地35~26 Ma期间的风化历史,探索这一时期青藏高原周缘风化演变的共同性和差异性。结果显示:青藏高原北部大部分区域自晚始新世起的风化强度便开始下降并延续至渐新世,与降温和干旱化过程相耦合;而东南缘则表现为多阶段的温度波动及持续湿润的气候特征。这种区域性差异主要由全球降温、构造隆升和季风系统演化的共同调控驱动。本研究为理解青藏高原不同区域在EOT期间的风化模式及其驱动机制提供了重要线索。The Eocene-Oligocene Transition(EOT)represents one of the most significant global cooling events of the Cenozoic era,marking a key shift in the Earth’s climate system from a“greenhouse”to an“icehouse”mode.While deep-sea sediment records consistently document this cooling event,numerous terrestrial records reveal significant spatial variability in climate responses across different regions,highlighting the importance of the interaction between global climate background and regional environments.The uplift of the Tibetan Plateau has significantly influenced global continental weathering patterns and is closely linked to Cenozoic global climate changes.Therefore,the evolution of continental weathering around the plateau provides an excellent indicator of both global and regional climate changes.This paper summarizes the weathering evolution records from the margins of the Tibetan Plateau during the Late Eocene to Oligocene,combining our weathering history from the Lühe Basin(35.5-25.5 Ma)in the southeastern Tibetan Plateau,to explore the commonalities and differences in weathering evolution during this period.The results show that in most regions of the northern Tibetan Plateau,weathering intensity decreased from the Late Eocene,coupled with cooling and aridification processes,while at the southeastern margin exhibited multi-stage temperature fluctuations and a sustained humid climate.This regional difference is mainly driven by the combined effects of global cooling,tectonic uplift,and the evolution of the monsoon system.This study provides crucial insights into the weathering patterns and driving mechanisms of different regions of the Tibetan Plateau during the EOT.

关 键 词：古气候 始新世—渐新世气候转型期 青藏高原 全球变化因素 区域因素 

分 类 号：P534.61[天文地球—古生物学与地层学] P532[天文地球—地质学]