长英质富晶体火山岩成因--岩浆补给与晶粥再活化  

Petrogenesis of the felsic crystal-rich volcanic rocks:Magma recharge and reactivation of the crystal mush

作　　者：赵思狄 夏炎[1] 徐夕生[1] 贺振宇 赵凯[1] ZHAO Si-di;XIA Yan;XU Xi-sheng;HE Zhen-yu;ZHAO Kai(State Key Laboratory for Mineral Deposits Research,School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]南京大学内生金属矿床成矿机制研究国家重点实验室,地球科学与工程学院,江苏南京210023 [2]北京科技大学土木与资源工程学院,北京100083

出　　处：《岩石矿物学杂志》2023年第6期878-893,共16页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金(41930214,42172052,42172070);中央高校基本科研业务费专项资金(XJ2023003901)。

摘　　要：火山是人类窥探深部岩浆系统的窗口。从全球范围来看,贫晶体富熔体的火山岩(尤其是玄武岩和流纹岩)大面积出露,而富晶体的长英质火山岩仅出露于破火山周围。长英质富晶体火山岩主要可分为两类:一类是成分和晶体含量均一的火山岩;另一类是成分和斑晶含量分带的火山岩。富晶体火山岩是冷储存晶粥接受岩浆反复补给后重熔、再活化,重新具备流动能力而喷发形成的,储库中先存物质的成分决定了再活化形成的富晶体火山岩的类型。富晶体火山岩的存在能够很好地解释岩浆储库具有较长的寿命而岩浆汇聚结晶的过程却是迅速的这种看似矛盾的现象。虽然近年来长英质富晶体火山岩的研究已经取得了明显的进展,但仍有许多问题亟待解决,如碎斑熔岩的成因,如何判别晶粥活化,晶粥再活化与火山喷发的关系,岩浆补给和晶粥活化的时间尺度等。对富晶体火山岩的进一步研究将有助于深入揭示熔体演化、运移、在浅部的聚集和喷发的机制,并可为建立更完善的长英质岩浆演化模型提供更多信息。Volcanoes are a window for humans to explore deep magma systems.From a global perspective,crystal-poor and melt-rich volcanic rocks(especially basalt and rhyolite)are mainly exposed all over the earth,while crystal-rich felsic volcanic rocks exposed around many calderas.The felsic crystal-rich volcanic rocks can be mainly divided into two types:one type is the volcanic rocks with homogenous composition and crystal contents;the other type is the volcanic rocks with zoned composition and crystal contents.The crystal-rich volcanic rocks erupted due to the cold stored crystal mush was remelted,reactivated,and remobilized after being repeatedly recharged by hot magma.The composition of the preexisting materials in the reservoir constrained the type of crystal-rich volcanic rocks formed by reactivation.The existence of crystal-rich volcanic rocks can well explain the contradictory phenomenon that the magma reservoir has a long life,but the process of magma accumulation and crystallization is rapid.Although the research of felsic crystal-rich volcanic rocks has made obvious progress in recent years,there are still many problems to be solved,such as the origin of porphyritic lava,how to reveal the reactivation of crystal mush,the relationship between crystal mush reactivation and volcanic eruption,the time scale of magma recharge and crystal mush reactivation,etc.Further research on crystal-rich volcanic rocks will promote the understanding of the mechanisms of melt evolution,migration,and shallow accumulation and eruption,providing more information for establishing a more comprehensive model of felsic magma evolution.

关 键 词：富晶体火山岩 岩浆补给 晶粥再活化 中国东南部 碎斑熔岩 

分 类 号：P588.14[天文地球—岩石学] P581[天文地球—地质学]