南海中、南部断裂体系及其构造意义  

FRACTURE SYSTEMS AND THEIR TECTONIC SIGNIFICANCE IN THE CENTRAL AND SOUTHERN PARTS OF THE SOUTH CHINA SEA

作　　者：邱燕[1] 曾维军[2] 李唐根[2] 

机构地区：[1]中山大学地球科学系,广东广州510275 [2]广州海洋地质调查局,广东广州510760

出　　处：《大地构造与成矿学》2005年第2期166-175,共10页Geotectonica et Metallogenia

摘　　要：中新生代时期,欧亚板块、太平洋-菲律宾海板块、印度-澳大利亚板块等几大板块之间的相对运动和相互作用,导致南海中、南部形成复杂的断裂体系和构造格局。本文利用两种主要的解释方法在该海域识别出断裂达数百条之多,以张性正断层为主。按其发育规模可分为三级:一级断裂为板块缝合线、俯冲带、大型裂谷带和走滑带;二级断裂一般延伸上百公里并切穿沉积基底,断距较大,往往控制其两侧的地层发育;三级断裂规模相对较小,主要在新生界内发育,与邻近的二级断裂有明显的成因联系。依据断裂的分带性将区内的断裂构造体系划分为西缘断裂体系、西南缘断裂体系、东南缘断裂体系、东缘断裂体系、岛礁区断裂体系和海盆断裂体系。本区断裂的发生发展过程与构造活动密切相关,不同的断裂发育期次反映了不同的区域构造活动。本区断裂发育期次可分为三期,其发育时间为第一期(K -E2 )、第二期(E3 -N2 )和第三期(N3 -Q)。The complicated fracture systems and tectonic framework were formed in the central and southern parts of the South China Sea due to the reciprocal movement of the plates like the Euro-Asia Plate, the Pacific-Philippine Plate and the India-Australia Plate during Mesozoic and Cenozoic. Over several hundreds of faults in this (area) and almost all tensional normal faults have been distinguished in this paper based on interpretation of the seismic profiles in addition to gravity and magnetic information. The fractures can be divided into three grades according to the scale of their development. Faults of the biggest scale are sutures, subduction zones, large rift zones and strike-slip fault zones and fault of the second scale can usually extend over one hundred kilometers in horizon and stretch to basement with long fault displacement in vertical direction and usually control the development of the strata on the fault sides. Faults of the smallest scale were mainly developed in the Cenozoic strata. The fracture structural systems can be separated into western margin system, southwestern margin system, southeastern margin system, eastern margin system, island and reef part system and deep-sea area system. The formation and development of these fractures are tightly interrelated with tectonic activities and different fault forming phases in association with the different tectonic activities. The fault forming phases can be divided into three epochs, i.e., the first phase (K_2-E^2_2), the second phase (E^3_2-N^2_1) and the third phase (N^3_1-Q).

关 键 词：南海中南部 断裂体系 张性正断层 构造格局 构造意义 

分 类 号：P542[天文地球—构造地质学]