Magmatism-Related Thermal Simulation of Volcanic Arcs in the Molucca Sea Bidirectional Subduction System  

作　　者：YU Lei ZHANG Jian DONG Miao FANG Gui Yu Lupeng 

机构地区：[1]Shandong Key Laboratory of Water and Soil Conservation and Environmental Protection,School of Resources and Environment,Linyi University,Linyi 276000,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Institute of Geology and Geophysics,Chinese Academy of Science,Beijing 100029,China

出　　处：《Journal of Ocean University of China》2023年第4期939-948,共10页中国海洋大学学报（英文版）

基　　金：supported by the Natural Science Foundation of Shandong Province(No.ZR2021MD069);the Strategic Pioneer Science and Technology Special Project of the Chinese Academy of Sciences(No.XDB42020104);the National Natural Science Foundation of China(No.42176052);the Project of Introducing and Cultivating Young Talents in the Universities of Shandong Province(No.LUJIAOKEHAN-2021-51).

摘　　要：The bidirectional subduction system,island arc magmatic activities,and thermal structure of the forearc basin in the Molucca Sea are taken into consideration in this study.The active volcanic arcs on both sides of the bidirectional subduction zone in the Molucca Sea are undergoing arc-arc collisions.We applied a finite element thermal simulation method to reconstruct the thermal evolution history of the Molucca Sea Plate based on geophysical data.Then,we analyzed the thermodynamic characteristics of island arc volcanism on both sides of the bidirectional subduction zone.The results showed that at 10Myr,the oceanic ridge of the Molucca Sea Plate was asymmetrically biased to the west,causing this bidirectional subduction to be deeper in the west than in the east.Furthermore,the oceanic ridge subducted under the Sangihe arc at 5.5Myr,causing intermittent cessation of volcanic activities.Due to the convergence of bidirectional subduction,the geothermal gradient in the top 3km depth of the forearc area between the Sangihe and Halmahera arcs decreased from about 60℃km^(−1) at 4Myr to about 38℃km^(−1) today.Finally,within the 45–100 km depth range of the sliding surface of the subduction,anomalously high-temperature zones formed due to shear friction during the bidirectional subduction.

关 键 词：Molucca Sea bidirectional subduction zone ARC thermal simulation:island-arc magmatism 

分 类 号：P588.11[天文地球—岩石学] P542[天文地球—地质学]