【摘要】 北部湾盆地涠西南凹陷的断裂系统十分复杂,为了揭示其成因机制,在三维地震资料构造解析的基础上,应用砂箱物理模拟技术,对涠西南凹陷的形成机制进行了系统研究。结果表明,南北向的"不协调伸展作用实验模型"能够成功地模拟涠西南凹陷晚始新世以来复杂的断裂系统,断裂系统的主体特征在这一实验模型中均得到了很好的再现。涠西南凹陷复杂的断裂系统是在基底先存构造基础之上,在递进变形过程中逐渐形成的,其裂陷期(晚始新世-渐新世)断裂系统是在一个伸展期内形成(南北向伸展)、并非是多期构造叠加变形的结果。这一认识不但能够有效地指导涠西南凹陷三维地震资料的精细构造解释,同时也能够为南海周缘盆地的形成和演化研究提供借鉴。更多还原

【Abstract】 The fault system of Weixinan Depression in the Beibu-Gulf Basin is very complex. In order to reveal the genetic mechanism, this paper applies sandbox modelling technologies to make a systemic analysis on the formation mechanism of Weixinan Depression fault system on the basis of systematic structural analysis of 3D seismic data. After several physical simulation experiments, the south-north direction experimental model of disharmonic extension can successfully reproduce the complicated fault system of Weixinan Depression, and the major characteristics have clear appearance in this experimental model. The complicated fault system of Weixinan Depression was formed gradually during progressive deformation on the basis of the pre- existed basement structure, and the fault system of main rifting phase (Late Eocene-Oliqocene) was formed just by one extension stage (NS trending), but not the result of multi-stage superimposed deformation. This understanding not only can interpretet the fine structure of 3D seismic data in Weixinan Depression, but also can provide a reference for studying the formation and evolution of the peripheal basins of the South China Sea.更多还原