Mineralogical and Geochemical Constraints on the Mantle Source Characteristics of Basaltic Lavas from the Central Mariana Trough  

作　　者：LAI Zhiqing GAO Wei HAN Zongzhu GUO Kun ZHONG Shihua ZHAO Guangtao 

机构地区：[1]Key Laboratory of Submarine Geosciences and Prospecting Techniques,MOE and College of Marine Geosciences,Ocean University of China,Qingdao 266100,China [2]Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China [3]National Deep Sea Center,Qingdao 266237,China [4]Center for Isotope Geochemistry and Geochronology,Pilot National Laboratory for Marine Science and Technology(Qingdao,Qingdao 266237,China

出　　处：《Journal of Ocean University of China》2023年第5期1313-1325,共13页中国海洋大学学报（英文版）

基　　金：the Shandong Provincial Natural Science Foundation,China(Nos.ZR2017PD002 and ZR2019BD010);the Open Fund of the Key Laboratory of Marine Geology and Environment,Chinese Academy of Sciences(Nos.MGE2019KG05 and MG E2021KG01);the Fundamental Research Funds for the Central Universities(No.202051009)。

摘　　要：The composition of mantle-derived basalts reflects the nature of their mantle source regions,which constrain magma generation and composition.Here we present a new whole rock major and trace elements and phenocryst composition of the basaltic lava in the central Mariana Trough.These data provide insights into the mantle source characteristics affected by subduction components.The rocks range from basalts to basaltic andesites,which have high subduction-mobile element contents(e.g.,K,U,Th,LREE)related to N-MORB.The calculated temperature and depth of magma generation are about 1300℃and 30 km,respectively.Although the results above suggest that the addition of hydrous fluid and/or a melt derived from a slab decreases the temperature of mantle partial melting and mildly modifies the composition of a mantle source,the mantle source lithology from which primary magma is generated remains to be peridotite.

关 键 词：backarc basin basalt subduction component mantle lithology magma generation 

分 类 号：P736.3[天文地球—海洋地质]