马里亚纳海槽岩浆作用研究进展  

Progress of the researches on magmatism in the Mariana Trough

作　　者：胡延斌 来志庆[3] 李梦 乔则文 赵广涛[3] 韩宗珠[3] 国坤 HU Yanbin;LAI Zhiqing;LI Meng;QIAO Zewen;ZHAO Guangtao;HAN Zongzhu;GUO Kun(College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China;Yantai Center of Coastal Zone Geological Survey,China Geological Survey,Yantai 264000,China;Key Laboratory of Submarine Geosciences and Prospecting Techniques,MOE and College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;Laoshan Laboratory,Qingdao 266237,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]中国地质调查局烟台海岸带地质调查中心,烟台264000 [3]中国海洋大学海洋地球科学学院,海底科学与探测技术教育部重点实验室,青岛266100 [4]崂山实验室,青岛266237

出　　处：《海洋地质与第四纪地质》2023年第5期64-72,共9页Marine Geology & Quaternary Geology

基　　金：山东省自然科学基金项目“冲绳海槽岩浆差异演化过程的斑晶矿物示踪研究”(ZR2017PD002);中国科学院海洋地质与环境重点实验室开放基金课题“马尔库斯-威克海山区地幔性状及其玄武岩成因研究”(MGE2019KG05)。

摘　　要：西太平洋俯冲带是世界上最典型、最活跃的俯冲带,分布众多的海沟-岛弧-弧后盆地(沟弧盆)系统。马里亚纳俯冲带是典型的洋-洋俯冲带,而马里亚纳海槽作为马里亚纳俯冲带的重要构造单元,是研究不受陆壳物质影响的俯冲作用的理想区域。前人对马里亚纳海槽岩浆地幔源区性状、俯冲组分的影响、岩浆演化等进行了详细研究。结果表明:(1)马里亚纳海槽岩浆源区主要为亏损地幔,岩性主要为橄榄岩,且不同区段具有不一致的地幔部分熔融程度;(2)不同区段受到来自蚀变洋壳及沉积物的俯冲组分的影响程度也不同,并由此影响了不同区段的地幔熔融程度和初始岩浆成分;(3)俯冲组分的影响自中段向南北两段逐渐加强,中段主要受到来自沉积物熔体的影响,南、北段受到板片释放的含水流体的影响则更为明显;(4)不同区段甚至同一区段的岩浆在演化过程中,经历了橄榄石、辉石、斜长石等斑晶矿物的差异性分离结晶过程,这也很好地解释了该区丰富的岩石类型和玄武质岩石的不同矿物组合特征。以上研究很好地促进了对马里亚纳海槽岩浆作用过程的认识,也深化了对俯冲带构造-岩浆作用的理解。The Western Pacific subduction zone is one of the most typical and active ones in the world,featuring a vast distribution of trench-island arc-back-arc basin systems.The Mariana subduction zone is a typical ocean-ocean subduction zone,and the Mariana Trough is an important component tectonic unit and an ideal area to elucidate the subduction without the influence of continental crust materials.The magmatic processes of the Mariana Trough were studied in detail,such as rock mantle source properties,subduction components,and magmatic evolution.The research clarified that:(1)the magma source in the Mariana Trough is mostly depleted mantle as it features peridotite dominance and the degree of partial melting of the source mantle varies in different regions.(2)The subduction components from altered oceanic crust and sediments in different parts are affected to different degrees of mantle melting and initial magma composition in different regions.(3)The influence of subduction components gradually increased from the middle section to the north and south sections.The middle section was mainly affected by melt from sediments,and the south and north sections were more significantly affected by hydrous fluids.(4)During the magma evolution in different regions or even in the same region,the fractional crystallization of olivine,pyroxene,and plagioclase can well explain the diverse rock types and different phenocryst assemblages in basaltic rocks.The achievements above could promote the understanding of the magmatism process in the Mariana Trough and also strengthen the deep understanding of tectonic-magmatism in the subduction zone.

关 键 词：地幔熔融 俯冲组分 岩浆演化 弧后盆地 西太平洋 

分 类 号：P736.21[天文地球—海洋地质]