摘要
【意义】自工业革命以来,人类在使用化石燃料的过程中不断向大气排放CO_(2)等温室气体,引起了剧烈的气候环境扰动和严重的生物危机。古新世—始新世极热事件(Paleocene-Eocene Thermal Maximum,PETM,~56 Ma)转折期发生了巨量的碳排放事件,碳排放速率与当前的排放进程最为接近,探索PETM时期的碳排放对地球宜居性影响的过程和机制,可以为预估地球未来气候变化趋势提供地质案例,具有重要的科学意义。【进展】关于PETM碳排放的触发机制问题目前仍存在争议,已有研究证实北大西洋火成岩省(North Atlantic Igneous Province,NAIP)的岩浆活动与PETM之间存在时间耦合性,表明NAIP可能触发了这一地球宜居性扰动事件,但是目前该转折期火山活动和气候环境波动的因果关系尚不明晰,其最大的难点在于如何在沉积岩中示踪火山活动记录。近年来,沉积物中的汞元素浓度及其同位素已被广泛用于示踪地质历史时期的火山活动。但是,目前对PETM事件的汞记录研究主要集中在靠近NAIP喷发区域的近岸地区,缺乏对远离喷发中心的开阔海地区的研究,制约了对NAIP活动影响范围和环境效应的认知。【结论与展望】本文针对PETM事件汞沉积示踪古火山活动的研究现状进行了系统的回顾,梳理了NAIP与PETM之间的联系,强调未来需借助汞同位素等其他指标踪及地球系统模型等进一步准确示踪火山活动,以深化对PETM的认知并为预估未来气候趋势提供依据。
[Significance]Since the beginning of the Industrial Revolution,human activities have resulted in the sustained release of greenhouse gases,including carbon dioxide(CO_(2))into the atmosphere.This has been primarily driven by the combustion of fossil fuels,and threatens profound climatic disturbances,environmental transformations and widespread biological crises.Similarly,the Paleocene-Eocene Thermal Maximum(PETM,~56 Ma)represents a period of massive carbon release into the atmosphere,occurring at a rate strikingly comparable to current anthropo⁃genic carbon emissions.It is of paramount importance to gain a comprehensive understanding of the processes and mechanisms that regulated carbon release during the PETM.Such knowledge can provide valuable insights into the impact of these emissions on the Earth’s habitability.Furthermore,these findings have significant implications for our attempts to gain an understanding of present-day and future climate change.It is consequently of the highest scientific importance to study this ancient climatic event,as it offers a natural experiment for evaluating the potential consequences of contemporary carbon emissions on global climate dynamics and ecological stability.[Progress]The trigger of the PETM has been the subject of considerable debate among scholars in the past few decades.Despite extensive research,the exact mechanism that instigated the massive carbon release during the PETM remains unresolved,although the findings of recent studies have indicated a temporal correlation between magmatism in the North Atlantic Igneous Province(NAIP)and the PETM.This evidence suggests that volcanic activity in NAIP was likely to be have been the trigger of the climatic perturbation.While this hypothesis adds to our insights into the triggering mechanisms of PETM events,our understanding of the exact cause-and-effect relationship between volcanic activity and climate fluctuations during this transition period remains incomplete.A significant challenge to a full establishing this relationship is the difficulty of accurately tracing volcanic activity in the sedimentary record during this period,due to the complex nature of volcanic products and their subsequent alteration over millions of years and the problem of identifying and distinguishing between different volcanic events.Recently,mercury(Hg)concentrations and their isotopic compositions in sediments have emerged as promising tools for tracing volcanic activity throughout geological history.However,in the present study,the focus on the Hg record of the PETM was largely limited to near-shore areas proximal to the NAIP eruption sites.Few studies have explored the Hg concentra⁃tions in sediments from open-ocean regions located at a considerable distance from the eruption centers,leaving a significant gap in our understanding of the broader extent of the influence of the NAIP.The spatial limitations of this study restricted our ability to fully assess the global impact of volcanic emissions on the Earth’s climate and ecosystems during the PETM.[Conclusions and Prospects]This paper provides a comprehensive review of the current state of research on the use of mercury deposition as a tracer of ancient volcanic activity during the PETM.It identifies existing research limitations and suggests key directions for future studies.It also reviews the possible relationship between the volcanic activity of the NAIP and the climatic events of the PETM,emphasizing the need for further interdisciplinary research to resolve outstanding issues and refine our understanding of this critical period in the Earth’s history.
作者
杨晨
林雯洁
金思敏
李明松
沈俊
YANG Chen;LIN WenJie;JIN SiMin;LI MingSong;SHEN Jun(State Key Laboratory of Geomicrobiology and Environmental Changes,China University of Geosciences,Wuhan 430074,China;School of Environmental Studies,China University of Geosciences,Wuhan 430074,China;Key Laboratory of Orogenic Belts and Crustal Evolution,Ministry of Education,School of Earth and Space Sciences,Peking University,Beijing 100871,China)
出处
《沉积学报》
北大核心
2025年第6期1935-1951,共17页
Acta Sedimentologica Sinica
基金
国家重点研发计划(2022YFF0802900)
国家自然科学基金项目(42405053)。
关键词
古新世—始新世极热事件
北大西洋火成岩省
汞浓度及同位素
海洋缺氧
Paleocene-Eocene Thermal Maximum
North Atlantic Igneous Province
mercury concentrations and isotopes
ocean deoxygenation
