【摘要】 <正>冲绳海槽盆地通常指的是东海陆架以东,琉球群岛以西,北起西南日本岸外,南至台湾宜兰附近的一个为海水淹盖的大型沉积盆地,南北长约1200公里,东西宽约100—150公里,分布面积约14万平方公里.由于盆地处在活动大陆边缘的沟-弧-盆体系中,大地构造位置比较特殊(图1),早已引起国内外地质学家们的兴趣.从六十年代开始,日、美、苏等国先后都对冲绳海槽区域进行了一些海洋地质与地球物理的调查研究.七十年代以来我国地质矿产部、国家海洋局、石油工业部及中国科学院海洋研究所等单位,也先后对冲绳海槽地区进行了一些海洋地质与地球物理调查.我们从八十年代开始,对该区进行了比较系统的海洋地质与综合地球物理调查,调查项目有海底沉积物取样、测深、重磁测量及多道地震调查等.本文就是在总结各项调查成果的基础上,对冲绳海槽盆地的地质构造特征与盆地的演化作一些探讨.更多还原

【Abstract】 Based on the data of geological and geophysical investigetion there exist three stratigraphical units in the Okinawa Trough Basin, i. e. the lower deformational strata, the middle slightly deformational strata and the horizontal strata. They are separated by unconformities. Their ages are the Middle-Late Miocene, Pliocene-Early Pleistocene and Middle Pleistocene-Holocene respectively. Several tectonic-magmatic events occured during the evolutionary process of the through basin. There are two important events, the first occured in the LateMiocene and the second in the Early Pleistocene. The latter resulted in obvious effects on the basin. Main forms of the crust movements are regional elevation, tilting, tensional faulting and large-scale volcanic eruption etc. Because the basin is located in an active continental margin, the basin remained in an unstable state in the course of formation and evolution, but its main tectonic framework is dominanted by the trench-arc-basin system. It shows NE-trend arc zone and step-like faulted blocks divided by NW-trend faults. Recent bathymetry also reflects such charateristic. Igneous rocks developed extensively in the basin, mainly in its east and west sides, forming two active zones of igneous rocks. Their developments reflected activity of the basin. Because of the unsta-bility of the basin, its formation and development are different from evolutional model of general basin (craton and ocean basin), its evolutionary historyconsists of three stages:initiation→extension→overgrowth. The latter shows activity of the basin. This activity might result from the Philippine Plate subduc-tion.更多还原