摘要
火山活动在古生态环境及生物演化过程中扮演重要角色。本研究以扬子地区奥陶纪/志留纪的火山活动记录为主要研究对象,结合准噶尔盆地、鄂尔多斯盆地、三塘湖盆地地质历史时期的火山活动记录及世界各地的现代火山活动,解析了火山活动对沉积古环境及有机质富集的影响机制。地质历史时期形成的凝灰岩、沉凝灰岩、斑脱岩及含凝灰质沉积岩是火山活动的物质表现,本研究通过对其从宏观到微观的岩石学、矿物学、地球化学特征进行分析,建立起一套多角度识别火山活动的剖面岩心—微观结构—全岩矿物—地球化学综合判断法。火山活动释放的营养元素导致海洋生物勃发、初级生产力上升,利于有机质积累,而有毒物质则危害生物生存,降低初级生产力。火山活动释放营养元素与有毒物质的相对含量可能影响海洋初级生产力的最终结果。低强度火山活动促进生物繁衍,剧烈的火山活动不断加大生态环境的修复压力,最终造成不可逆的破坏。火山活动加剧水体缺氧,提高有机质保存效率。火山气体形成硫酸气溶胶增加行星反照率,造成地表温度下降。
Volcanic activity greatly affected the palaeoecological environment and biological evolution process.This study focuses on examining the volcanic activity records during the Ordovician/Silurian period in the Yangtze area.We incorporates the volcanic activity records from the Junggar Basin,Ordos Basin,and Santanghu Basin,as well as modern volcanic activities worldwide to elucidate the influence mechanism of volcanic activity on sedimentary palaeo-environment and organic matter enrichment.Tuff,sedimentary tuff,bentonite and tuffaceous sedimentary rocks formed in geological history are good proxy of volcanic activities.Through the analysis of the petrology,mineralogy and geochemical characteristics from macro-to micro-scale,this study established a comprehensive judgment method of multi-angle assessment of volcanic activity in the section core-microstructure-whole rock minerals-geochemistry.The nutrient elements released by volcanic activities lead to the proliferation of marine organisms and the increase of primary productivity,which is conducive to the accumulation of organic matter,while toxic substances impede the survival of organisms and reduce primary productivity.The relative amounts of nutrients and toxins released by volcanic activity may affect the primary productivity of the ocean.Low intensity volcanic activity can promote biological reproduction,while intense volcanic activity constantly increases the pressure of ecological environment restoration,ultimately resulting in irreversible damage.Volcanic activity intensifies water body hypoxia and enhances organic matter preservation efficiency.Sulphuric acid aerosols derived from volcanic gases increase planetary albedo and lower surface temperatures.
作者
谢浩然
梁超
吴靖
籍士超
XIE Haoran;LIANG Chao;WU Jing;JI Shichao(School of Geosciences,China University of Petroleum(East China),Shandong Qingdao 266580,China;State Key Laboratory of Deep Oil and Gas(China University of Petroleum(East China)),Shandong Qingdao 266580,China;School of Earth Science and Engineering,Shandong University of Science and Technology,Shandong Qingdao 266590,China)
出处
《古地理学报》
CAS
CSCD
北大核心
2023年第4期768-787,共20页
Journal of Palaeogeography：Chinese Edition
基金
国家自然科学基金(编号:42172165,41902134)
中央高校基本科研业务费专项资金(编号:22CX06001A)
泰山学者计划(编号:TSQN201812030)联合资助。
关键词
火山活动
火山活动识别
沉积环境响应
有机质富集
黑色页岩
volcanic activity
volcanism identification
sedimentary environment response
organic matter enrichment
black shale
