柴达木盆地西北部中新世矿物学特征及其古气候意义  

Mineralogical characteristics and paleoclimatic significance of the Miocene deposit in the northwestern Qaidam Basin

作　　者：秦秀玲 常宏[1] 关冲 QIN Xiuling;CHANG Hong;GUAN Chong(State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an 710061,China;University of Chinese Academy of Sciences,Beijing 100049,China;Xi’an Center of Geological Survey,China Geological Survey,Xi'an 710119,China)

机构地区：[1]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710061 [2]中国科学院大学,北京100049 [3]中国地质调查局西安地质调查中心,西安710119

出　　处：《海洋地质与第四纪地质》2025年第2期177-188,共12页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目“塔里木盆地钻孔岩芯记录的上新世气候变化特征及其影响因素”(42372221);第二次青藏高原综合科学考察项目“高原风化剥蚀历史及气候环境效应”(2019QZKK0707);黄土与第四纪地质国家重点实验室开放基金资助项目“柴达木盆地中中新世大暖期沉积序列的黏土矿物学研究”(SKLLQG2121)。

摘　　要：中中新世气候适宜期是新生代气候变冷背景下的一次短期气候变暖事件。研究此阶段沉积物记录的环境特征对预测未来全球变暖背景下气候变化趋势具有指导意义。亚洲内陆极端干旱区中中新世气候适宜期记录较少,而且该时段气候变化的受控因素仍未明确。本研究通过柴达木盆地北部花土沟剖面中新统矿物分析,明确了中新世全球气候变化重要事件在柴达木盆地环境变化过程中的响应,重点探讨黏土矿物干湿指标反演的柴达木盆地该时段古气候演化历史以及驱动机制。结果显示,柴达木盆地早—中中新世期间(17.2~15.2 Ma)气候最为温暖湿润,主要受全球中新世暖期气候的影响。15.2~12.4 Ma柴达木盆地气侯波动变干,盆地受区域构造与中中新世降温事件的共同影响。12.4~11.3 Ma柴达木盆地持续变干,主要受全球气候的影响。全球气候及区域构造运动共同影响柴达木盆地早—中中新世气候。The Middle Miocene Climatic Optimum(MMCO)is a short-term climate warming event interrupting the background of Cenozoic climate cooling.Study on the environmental characteristics based on sediments is important for predicting the trend of climate change with the global warming in the future.There are few records of the MMCO in the extreme arid interior of Asia,and the controlling factors of paleoclimate changes are still unclear.The mineral assemblages of the Miocene sediments from the Huatugou section in the northern Qaidam Basin were analyzed,the regional response to the global climate event and the environmental change in the Qaidam Basin during early-middle Miocene were revealed,and the paleoclimate evolution including the shifting and driving mechanisms of relative moisture index of clay minerals were focused.Results show that during the early-middle Miocene in Qaidam Basin,the climate during 17.2~15.2 Ma was the warmest and wettest,which should belong to the MMCO and mainly affected by the global climate.The climate in the basin began to fluctuate and became dried during 15.2~12.4 Ma.The basin was affected by the regional geological structure and the Middle Miocene cooling event.From 12.4 to 11.3 Ma,Qaidam Basin continued to dry out,mainly under the influence of global climate again.We pointed out that the global climate change trend and regional tectonic movement influenced the early and middle Miocene climate in Qaidam Basin.

关 键 词：矿物组合 构造运动 古气候 中新世 柴达木盆地 

分 类 号：P532[天文地球—古生物学与地层学]