摘要
二叠纪是地球演化历史进程中的重要一环,并在我国华南地区中二叠统茅口组(孤峰组)地层中普遍沉积一套层状硅质岩,它们可能与中、晚二叠世系列重大地质事件之间有着密切的成因联系。笔者等以位于扬子地块西南缘的贵州纳雍营盘茅口组硅质岩作为研究对象,通过对硅质岩元素地球化学组成进行研究发现,硅质岩Al/(A1+Fe+Mn)值以及多项成因判别图解等指示其形成过程中有明显的热水物质输入,具有热水成因硅质岩的特征。结合区域古地理特征,以及硅质岩Ce/Ce~*、(La/Ce)_(N)值等综合分析,认为硅质岩形成于黔中台沟内的深水环境。综合考虑区域范围内中二叠世硅质岩研究成果,并分析纳雍营盘硅质岩与峨眉山玄武岩空间关系及峨眉地幔柱活动历史,认为峨眉地幔柱早期海底火山活动可能对包括营盘在内的华南地区中二叠世晚期硅质岩沉积具有重要控制作用。
Objectives:The siliciclastic rocks of the Middle Permian Maokou Formation at Yingpan,Nayong,Guizhou,are the main object of this study,focusing on the genesis of siliciclastic rocks and the origin of defined silica usingelemental earth methods.Methods:Based on the field investigation work,the ratio characteristics and enrichment patterns of major,trace and rare earth elements were analyzed by elemental geochemical methods,combined with geologicalbackground and petrographic paleogeographic features to discern the siliciclastic genesis and depositionalenvironment.Results:Elemental geochemical correlation ratios and diagrams of diagenetic discrimination indicate that therewas a significant input of hot water material during the formation process,and silicon was mainly derived from thehot water system.The depositional environment is the Qianzhong Terrace Trench in the deep-water phase of thesame sedimentary fracture.Conclusions:The early submarine volcanism of the Emei mantle column or the associated hot water actionprovided the siliceous fraction required for the deposition of siliciclastic rocks at Yingpan,Nayong.And the earlysubmarine volcanism of the Emei mantle column may have an important controlling role on the Permian siliciclasticsedimentation in South China.
作者
杨贵园
高军波
杨瑞东
刘志臣
徐海
YANG Guiyuan;GAO Junbo;YANG Ruidong;LIU Zhichen;XU Hai(College of Resource and Environment Engineering,Guizhou University,Guiyang,550025;Key Laboratory of Karst Geological Resources and Environment,Ministry of Education,Guizhou University,Guiyang,550025;The 102 Geological Brigade,Guizhou Bureau of Geological and Mineral Exploration and Development,Zunyi,Guizhou,563003;Department of Tourism and Geography,Tongren University,Tongren,Guizhou,554300)
出处
《地质论评》
CAS
CSCD
北大核心
2022年第5期1621-1633,共13页
Geological Review
基金
国家自然科学基金资助项目(编号:42163006,41890841,U1812402)
贵州省沉积矿床科技创新人才团队项目(编号:黔科合平台人才[2018]5613)
贵州省人才基地项目(编号:RCJD2018-21)
贵州省研究生科研基金立项项目(编号:黔教合YJSCXJH[2020]181)的成果。
关键词
成因
硅质岩
二叠纪
纳雍营盘
贵州
diagenesis
siliciclastic rocks
Permian
Yingspan,Nayong
Guizhou
