太平洋CC区构造特征与多金属结核成矿条件研究  

A STUDY ON THE TECTONIC FEATURE AND POLYMETAL NODULE MINERALIZATION CONDITION IN THE CC REGION OF THE PACIFIC OCEAN

作　　者：王述功[1] 刘忠臣[1] 刘保华[1] 吴金龙[1] 

机构地区：[1]国家海洋局第一海洋研究所,青岛266003

出　　处：《海洋与湖沼》1999年第4期435-444,共10页Oceanologia Et Limnologia Sinica

基　　金："九五"中国大洋协会"资源评价与地质研究"项目!DY95-02-04

摘　　要：1994年4－11月，国家海洋局组织和实施了DY85－4航次中国开辟区（太平洋CC区）多金属结核（下简称结核）勘探，海上勘查历时225d,勘查面积达65×103km2，其中，用重力、磁力和单道地震等方法对测区进行了地球物理调查。结果表明，火山和浅层侵入体是提供给核生成的重要物质来源。区域性的沉积间断是造成结核丰度偏高的重要因素。断块活动强烈的地区，断裂活动有利于金属元素在海底的富集。不同时代形成的海底，地幔原岩在成分上的差异或在洋壳形成过程中构造活动的差异，对结核的形成有着一定的控制因素。而上述地质构造活动，在地球物理特征上都有着明显的反映。由此可见，地球物理特征与结核的形成和富集规律有着明显的相关关系。According to the Eighth Five-year plan of Oceanic polymetal Nedule Research and Developmnt of COMRA, the State Oceedc Administration (SOA) organized and carried out a polymetal nodule exploration chase DY85-4 in the CC region of the Pacific Ocean with a total area of 65 ｘ103km2 from April to NoVember, 1994, with a period of 225d.During the chase the geophysical inveshgations including gravity, mapnetics and single-channel seismic survey were conducted. A total single-channel seismic profile of 1 533.7km with a high resolution and gravity and magnehc profile of 2 227km with a high accaxy were obtalned.postprocessing and shatigraphical analyses for the seisAnc profiles have been undertaken. The Moho depth has been calculated by using sinx / x method based on the surveyed Bouguer anomaly. A theorehcal magnehc anomaly profile has been calculated using the tWo-dmensional plate formula and compared with the measared magnehc profiles, from which the age of ocean bottom wasdeterhaned.The resultS show tha tecdrically the volcedc achvihes dominate the west area and faulhng block achvihes play a leading ro1e in the east area. The difference in the tectonic background in the tWo areas causes the difference in the forInallon, djstribution, abundane and types of the polymetal nodule.The volcedcs and shallow intrUsive bodies provide the materia-l souree for the nodule. Especially the melt rock erupted up to the ocean bottom suppies the useful meta to water body (including bottOm water and interval water) by the bottom weathering, being adVantageous to the formation and concentalon of the nodule.ffegional sediment discontinuahon is caused mainly by the erosion due to bottom cunntS. ms eroding achon is very strong, which leeds to the sediment disconhnuahon or low sedimental nd since the Miocene over the west area. It may be one of the reasons for the relatively high nodule abundance is relatively hjgh in the area.lh the east area the faulhng block achvihes are qulte strong. From the analysis on the surveyed geophysical data, th

关 键 词：火山活动 多金属结核 成矿条件 太平洋 构造特征 

分 类 号：P744[天文地球—海洋科学] P618.205