马里亚纳海槽火山岩中斜长石熔体包裹体的均一温度及其对岩浆演化的指示意义  

Homogeneous temperature of plagioclase melt inclusions in volcanic rocks from the Mariana Trough and its implication to magma evolution

作　　者：张保辉 曾志刚[2,3] 曾志斌 杨小双 王晓媛 齐海燕[2] 殷学博[2] 陈帅[2] 陈祖兴[2,3] 韩超 ZHANG Baohui;ZENG Zhigang;ZENG Zhibin;YANG Xiaoshuang;WANG Xiaoyuan;QI Haiyan;YIN Xuebo;CHEN Shuai;CHEN Zuxing;HAN Chao(College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China;The Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;College of Marine Sciences,University of Chinese Academy of Sciences,Qingdao 266400,China;Henan Provincial Fifth Geological Exploration Institute,Zhengzhou 450001,China)

机构地区：[1]山东科技大学地球科学与工程学院,青岛266590 [2]中国科学院海洋研究所,中国科学院海洋地质与环境重点实验室,青岛266071 [3]中国科学院大学海洋学院,青岛266400 [4]河南省第五地质勘查院,郑州450001

出　　处：《海洋地质前沿》2025年第2期53-67,共15页Marine Geology Frontiers

基　　金：国家自然科学基金“深海界面过程和化能生态系统”“冲绳海槽与马里亚纳海槽的热液烟囱体特征及其对流体演化的指示”“西太平洋俯冲体系中岩浆活动及其对热液物质供给的制约”(42221005,42330409,91958213);中国科学院战略性先导科技专项子课题“热液/冷泉区岩浆物质贡献与流体化学过程”(XDB42020402);国家重点基础研究发展计划(973计划)项目“典型弧后盆地热液活动及其成矿机理”(2013CB429700);泰山学者工程(ts201511061)。

摘　　要：马里亚纳海槽南部安山岩(H5-T3-2)中斜长石结晶温度主要集中在1050~1150℃,未受到后期岩浆演化的影响。马里亚纳海槽中部玄武质安山岩(H5-T1-3)中斜长石结晶温度主要集中在900~1050℃;英安岩(H5-T1-1)中斜长石结晶温度主要集中在1050~1150℃。马里亚纳海槽18°N附近玄武岩(H5-T2-2、H5-T2-3)斜长石中熔体包裹体的均一温度主要集中在1050~1150℃,并呈连续降温趋势,只有少部分在1000~1050℃的较低温度结晶,边缘部An值骤降则反映岩浆喷出快速冷却的过程;玄武质安山岩(H5-T2-1)斜长石中熔体包裹体的均一温度具有“双峰”式特征,主要分布在850~950℃和1050~1150℃2个温度范围。结合斜长石的环带特征及其An值变化特征,分析结果表明,该斜长石有2个明显不同的结晶阶段,发生了岩浆混合作用,且在马里亚纳海槽浅部可能存在温度约为850~950℃的岩浆房,岩浆到达浅部岩浆房后发生岩浆混合,最终喷出洋底。马里亚纳海槽18°N附近的岩浆演化过程较为复杂,发生了不同周期的岩浆演化过程。The crystallization temperatures of plagioclase melt inclusions in volcanic rocks from the Mariana Trough was studied.Results show that those in andesite(H5-T3-2)from the southern Mariana Trough are mainly in 1050~1150℃and did not affected by later magmatic evolution;those in basaltic andesite(H5-T1-3)from the central Mariana Trough are mainly 900~1050℃;and those in dacite(H5-T1-1)are mainly 1050~1150℃.The homogenization temperatures of melt inclusions in basalt(H5-T2-2,H5-T2-3)plagioclase near 18°N in the Mariana Trough are mainly 1050~1150℃,showing a continuous cooling trend,and only a small part crystallizes at a lower temperature of 1000~1050℃,and the sudden drop in the An value at the edge of plagioclase phenocryst reflects a rapid cooling of the magma ejection.In addition,the homogenization temperature of the melt inclusions in basalt andesite(H5-T2-1)plagioclase showed the characteristics of"bimodal"pattern of 850~950℃and 1050~1150℃.The banding characteristics and the An value variation of plagioclase indicate that the plagioclase experienced two distinct crystallization stages and magma mixing,and there might be a magma chamber in the shallow part of the Mariana Trough,where the magma chamber temperature is about 850~950℃.The magmatic evolution process near 18°N in the Mariana Trough is complex,and different periods of magmatic evolution may occur.

关 键 词：马里亚纳海槽 斜长石 熔体包裹体 均一温度 岩浆演化 

分 类 号：P736.221[天文地球—海洋地质] Q915[天文地球—海洋科学]