胡延斌,来志庆,李梦,等. 马里亚纳海槽岩浆作用研究进展[J]. 海洋地质与第四纪地质,2023,43(5): 64-72. DOI: 10.16562/j.cnki.0256-1492.2023091601
引用本文: 胡延斌,来志庆,李梦,等. 马里亚纳海槽岩浆作用研究进展[J]. 海洋地质与第四纪地质,2023,43(5): 64-72. DOI: 10.16562/j.cnki.0256-1492.2023091601
HU Yanbin,LAI Zhiqing,LI Meng,et al. Progress of the researches on magmatism in the Mariana Trough[J]. Marine Geology & Quaternary Geology,2023,43(5):64-72. DOI: 10.16562/j.cnki.0256-1492.2023091601
Citation: HU Yanbin,LAI Zhiqing,LI Meng,et al. Progress of the researches on magmatism in the Mariana Trough[J]. Marine Geology & Quaternary Geology,2023,43(5):64-72. DOI: 10.16562/j.cnki.0256-1492.2023091601

马里亚纳海槽岩浆作用研究进展

Progress of the researches on magmatism in the Mariana Trough

  • 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。

     

    Abstract: 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.

     

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