从长英质侵入体揭示火山喷发过程与岩浆通道系统  

Insights into the volcanic eruption process and magmatic plumbing systems from felsic intrusions

作　　者：马昌前[1] 刘彬[2] 薛振华 邹博文 黄贵治 连泉程 高珂[1] 孙洋[2] 王连训[1] MA ChangQian;LIU Bin;XUE ZhengHua;ZOU BoWen;HUANG GuiZhi;LIAN QuanCheng;GAO Ke;SUN Yang;WANG LianXun(School of Earth Sciences,China University of Geosciences,Wuhan 430074,China;School of Geosciences,Yangtze University,Wuhan 430100,China)

机构地区：[1]中国地质大学(武汉)地球科学学院,武汉430074 [2]长江大学地球科学学院,武汉430100

出　　处：《岩石学报》2024年第7期1997-2018,共22页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(42130309、41972066)资助.

摘　　要：汇聚板块边缘的大型长英质火山喷发是地球上最具破坏性的自然灾害之一。然而,与这些火山相关的岩浆通道系统的结构及其对火山活动的控制方式迄今仍知之甚少。基于在青藏高原北部东昆仑造山带三叠纪火山岩与侵入体关系的观察以及全球岩浆通道系统的研究进展,本文提出要将火山机构与侵入体结合起来开展研究,通过重建岩浆通道系统来揭示侵入体(古岩浆储库)与火山活动的潜在联系。本文指出,地球上只有少部分侵入岩与火山活动存在密切关系,这些侵入岩可能是抽取火山喷发物质后留下的岩浆储库残余物质。有些岩浆储库不仅为火山喷发提供物质,还在提供火山喷发动力、控制火山喷发方式在溢流式与爆炸式之间的转换以及影响火山机构定位等方面发挥着关键作用。富挥发分的流体大量溢出地表会减少大型伟晶岩型和斑岩型矿床的形成机会,特别是在爆炸式的长英质火山喷发过程中。本文将岩浆通道系统划分为5个区域,即部分熔融区、岩浆聚集区、岩浆迁移区、岩浆侵位区和火山喷口区,这些区域构成了一个复杂的纵向递进、横向连接的岩浆网络系统,是构造环境(构造阶段)、地壳状态和岩浆动力学属性的耦合产物。为了深入理解长英质岩浆通道系统结构和动力学演化及其对火山活动机制的控制,本文建议要将火山机构、侵入体和围岩系统作为岩浆通道系统的组成部分,开展构造地质学、岩石学、矿物学、岩浆动力学、地球化学、地球物理学等多学科的综合研究,以精细解剖典型岩浆通道系统的组成和结构,重建其岩浆动力学过程。Large felsic volcanic eruptions at convergent plate boundaries are among the most destructive natural disasters on Earth.However,the architectures of the magma plumbing systems that feed these volcanoes and their controls on volcanic processes remain poorly understood.Based on observations of the relationships between Triassic volcanic rocks and intrusions in the eastern Kunlun orogenic belt in the northern Qinghai-Tibet Plateau,as well as recent advances in the study of global magma plumbing systems,this paper proposes to combine the study of volcanic edifices and intrusions,and to reconstruct the magma plumbing system to understand the potential connection between intrusions(ancient magma reservoirs)and volcanic activity.We stress that only a small portion of intrusive rocks worldwide have a close relationship with volcanic activity.These intrusions may represent the residual material of magma reservoirs left after volcanic eruptions.Some magma reservoirs not only feed volcanos,but also provide power to drive volcanic eruptions,and play a crucial role in the transition between explosive and effusive styles during eruptions,as well as influencing the location of volcanic edifices.The extensive release of volatile-rich fluids to the surface can reduce the formation of large pegmatite-type and porphyry-type deposits,especially during explosive felsic volcanic eruptions.This paper categorizes the magma plumbing system into five zones,namely,partial melting zone,magma accumulation zone,magma migration zone,magma emplacement zone and volcanic vent zone.These regions form a complex,vertically progressive and laterally interconnected magma network system,which is a product of the coupling between the tectonic settings(tectonic stages),crustal state and magmatic dynamic properties.To gain a deeper understanding of the architecture and dynamic evolution of a felsic magma plumbing system,as well as its control over volcanic activity mechanisms,this paper suggests considering volcanic edifices,intrusions,and surrounding ro

关 键 词：东昆仑 长英质岩浆 岩浆通道系统 火山喷发方式 侵入体 岩浆动力学 

分 类 号：P317[天文地球—固体地球物理学] P588.11[天文地球—地球物理学]