青藏高原典型时段火山活动碳释放规模及其环境意义  

Carbon output fluxes of volcanic activity during typical geological periods on the Tibetan Plateau and related environmental implications

作　　者：谢显刚 赵文斌 张茂亮 郭正府[1] 徐胜 XIE Xiangang;ZHAO Wenbin;ZHANG Maoliang;GUO Zhengfu;XU Sheng(State Key Laboratory of Lithospheric and Environmental Coevolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;School of Earth System Science,Tianjin University,Tianjin 300072,China)

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化与环境演变全国重点实验室,北京100029 [2]天津大学地球系统科学学院,天津300072

出　　处：《地学前缘》2025年第3期350-361,共12页Earth Science Frontiers

基　　金：国家重点研发计划项目(2020YFA0607700);国家自然科学基金项目(41930642)。

摘　　要：火山活动等地球深部过程对气候环境的影响是全球变化研究领域的重要议题。新生代青藏高原隆升伴随着多期火山活动和深部碳释放,并且这一时期大气CO_(2)浓度发生阶段性变化,亚洲气候环境格局由行星风系主控转向季风主控。然而,青藏高原火山活动与气候环境变化之间的内在联系尚不明确,原因在于缺乏火山活动深部碳释放规模的直接约束。本文聚焦青藏高原碰撞后火山活动,以拉萨地块查孜、米巴勒地区的中新世火山岩和羌塘地块依布茶卡、俄久买马、鱼鳞山地区的渐新世火山岩为研究对象,利用激光原位拉曼光谱测定了火山岩斑晶的熔体包裹体CO_(2)浓度,进而结合火山岩体积和年龄等参数,估算了拉萨地块中新世火山活动和羌塘地块渐新世火山活动的CO_(2)释放通量。结果表明,拉萨地块和羌塘地块火山岩CO_(2)平均浓度分别为(1.73±0.59)%和(0.46±0.07)%,由此计算得到的拉萨地块中新世火山活动和羌塘地块渐新世火山活动CO_(2)释放通量分别为(0.252±0.091)Pg·a^(-1)和(0.012±0.002)Pg·a^(-1)。羌塘地块较低的渐新世火山CO_(2)释放通量与同时期大气CO_(2)浓度快速下降特征一致;拉萨地块较高的中新世火山CO_(2)释放通量可能对中中新世气候适宜期的大气CO_(2)浓度峰值有一定贡献。青藏高原火山活动深部碳释放通量与大气CO_(2)浓度的近似同步变化特征表明,印度-亚洲大陆碰撞和俯冲导致的火山活动是新生代大气碳收支的重要影响因素。Volcanic activity and deep earth processes significantly influence climatic and environmental changes,making them a critical topic in global change research.The uplift of the Tibetan Plateau during the Cenozoic was accompanied by multiple phases of volcanic activity and deep carbon release,while atmospheric CO_(2) concentrations underwent periodic changes.During this period,the Asian climate shifted from being predominantly controlled by planetary wind systems to a monsoon-dominated regime.However,whether there is an intrinsic connection between volcanic activity on the Tibetan Plateau and climatic-environmental changes remains unclear due to the lack of direct constraints on the output of deep carbon release from volcanic activity.This study focuses on post-collisional volcanic activity on the Tibetan Plateau,analyzing Miocene volcanic rocks from the Chazi and Mibale areas of the Lhasa block and Oligocene volcanic rocks from the Yibuchaka,Ejumaima,and Yulishan areas of the Qiangtang block.Using laser in-situ Raman spectroscopy,the CO_(2) concentrations in melt inclusions within phenocrysts of these volcanic rocks were determined.Combined with parameters such as volcanic rock volume and age,we estimated the CO_(2) output from volcanic activity in the Lhasa block and Qiangtang block.The results show that the average CO_(2) concentrations in volcanic rocks from the Lhasa block and Qiangtang block are approximately(1.73±0.59)%and(0.46±0.07)%,respectively.Based on volcanic rock volumes,the estimated CO_(2) flux from volcanic activity in the Lhasa block and Qiangtang block is(0.252±0.091)Pg·a^(-1) and(0.012±0.002)Pg·a^(-1),respectively.The lower CO_(2) flux from Oligocene volcanic activity in the Qiangtang block is consistent with the rapid decline in atmospheric CO_(2) concentration during this period,while the higher CO_(2) flux from Miocene volcanic activity in the Lhasa block may have contributed to the peak in atmospheric CO_(2) concentration during the Middle Miocene Climate Optimum.The approximate synchro

关 键 词：火山活动 CO_(2)释放通量 青藏高原 熔体包裹体 

分 类 号：P317[天文地球—固体地球物理学] X142[天文地球—地球物理学]