冲绳海槽南部海底热液活动区地形地貌特征及成因分析  

Topographic features of the hydrothermal field and their genetic mechanisms in southern Okinawa Trough

作　　者：尚鲁宁[1] 陈磊[2] 张训华[3] 曾志刚[2] 张勇[1] 骆迪[1] SHANG Luning;CHEN Lei;ZHANG Xunhua;ZENG Zhigang;ZHANG Yong;LUO Di(Qingdao Institute of Marine Geology,Qingdao 266071, China;Institute of Oceanology, Chinese Academy of Sciences,Qingdao 266071, China;Nanjing Center, China Geological Survey,Nanjing 210016, China)

机构地区：[1]青岛海洋地质研究所,青岛266071 [2]中国科学院海洋研究所,青岛266071 [3]中国地质调查局南京地质调查中心,南京210016

出　　处：《海洋地质与第四纪地质》2019年第4期12-22,共11页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目“鱼山-久米断裂带构造特征及其对中新世以来东海东部构造演化的分隔控制”(41606050);“冲绳海槽北部火山岩三维位场统计学联合反演及多属性聚类成像”(41506085);中国地质调查局项目“东部海域1:100万海洋区域地质调查成果集成与应用”(DD20160137);国家重点基础研究发展计划项目“典型弧后盆地热液活动及成矿机理”(2013CB429701)

摘　　要：为了进一步理解构造地质过程对弧后盆地热液活动及成矿作用的影响和控制,以实测和收集的多波束资料为基础,对冲绳海槽南部多个海底热液活动区的地形地貌特征进行了精细刻画。结合前人研究成果,从构造地质学的角度分析了热液区地形地貌的成因机制。结果表明,冲绳海槽南部热液区均为海底火山成因地貌,不同热液区的海底地貌分属于不同类型岩浆作用的产物:D海丘受岛弧和弧后盆地岩浆作用的双重影响,A海丘群由岛弧为主的多源岩浆作用产生,C海丘和B海丘群属于琉球火山岛弧,雨花海丘形成于造山期后地壳伸展导致的岩浆上涌。冲绳海槽中央地堑与琉球火山岛弧的交汇处有利于形成大规模岩浆和地热活动。琉球火山岛弧的岩浆活动存在时空迁移,与海槽构造演化过程中由分散式裂陷向中心式裂陷的转换有关。唐印热液区的存在表明台湾北火山带在槽底北缘及陆坡区仍具有较强的岩浆和地热活动性,是未来冲绳海槽南部海底热液调查的重要靶区之一。In order to better understand the role of tectonic processes in submarine hydrothermal activity and mineralization in back-arc basins, we documented herewith the multi-beam sounding data from the southern Okinawa Trough and detailedly depicted the topographic features of some hydrothermal fields concerned. Combined with the results in previous publications, we analyzed the genetic mechanisms of the topographic features from the viewpoint of tectonics. Topographic features in all of the hydrothermal fields are formed by submarine volcanism. Nevertheless, features of different hydrothermal fields are essentially depending upon the distinct types of magmatism. The D Knoll was influenced by both the arc and back-arc magmatisms;the A Knolls were formed by multi-source magmatism predominated by arc magmatism;the C Knoll and the B Knolls are part of the Ryukyu Volcanic Arc;and the Yuhua Knoll was generated by the magmatism induced by the post-collisional lithospheric extension. The intensity of the Ryukyu Volcanic Arc magmatism shows a trend of migration both temporally and spatially, which may be attributed to the transition from disperse rifting to the focus rifting. The occurrence of the Tangyin hydrothermal field indicates that the magmatism of the Northern Taiwan Volcanic Zone in the continental slop region is strong enough to drive vigorous hydrothermal circulation. Thus this region is an important target area for hydrothermal surveys in the future.

关 键 词：海底地形 热液活动区 多波束 海底构造 冲绳海槽 

分 类 号：P737.2[天文地球—海洋地质]