【摘要】 悉尼盆地位于澳大利亚东部,Lachlan褶皱带和New England褶皱带之间。悉尼盆地从晚石炭世末到中三叠世经历了弧后扩张到前陆盆地的不同阶段:弧后扩张阶段(石炭纪)、被动热沉降阶段(早、中二叠世Berry组)和挤压挠曲负载阶段(中二叠世Broughton组—三叠纪)。此时位于悉尼盆地东侧的New England褶皱带为岛弧背景。因此,二叠纪处于弧后盆地的南悉尼盆地受弧后扩张和东侧弧前海沟俯冲的影响地震活动强烈,发育一系列与地震有关的震积岩,形成多种类型的与地震活动有关的软沉积物变形构造。南悉尼盆地二叠系的软沉积物变形包括地裂缝、震褶层、液化脉、沙火山、负荷构造、火焰构造、枕状构造、球状构造、枕状层、滑塌构造、角砾岩化等。其中地裂缝、震褶层是地震颤动直接引起的断裂和褶皱;枕状层是地震颤动引起的砂层脱水、下沉形成的;液化脉、沙火山为液化的砂层穿入地震形成的裂隙形成的;负荷构造、火焰构造、枕状构造、球状构造是受地震颤动在砂、泥岩界面上由于砂层下沉、泥层上穿形成的;滑塌构造和角砾岩化是地震引起的重力滑塌或泥石流形成的。地裂缝、震褶层、液化脉、沙火山、负荷构造、火焰构造、枕状构造、球状构造、枕状层相当于原地震积岩,而滑塌构造和角砾岩化属于异地震积岩。更多还原

【Abstract】 The southern Sydney Basin is located in the southernmost part of the north-south trending Bowen-Gunnedah-Sydney Basin system, bordering the New England Fold Belt in the northeast and the Lachlan Fold Belt to the west. As such, the study area is generally considered to be part of a large foreland basin system within the Tasman Fold Belt of eastern Australia. Various studies have indicated that the southern Sydney Basin evolved from a back-arc extensional phase in the latest Carboniferous, through a passive thermal sag phase from the Early Permian to Middle Permian, to a typical foreland basin setting from the Late Permian to Middle Triassic characterized by tectonic stacking (from the east and northeast), flexural loading and increased compression. Tn back-arc Sydney Basin was intensely affected by back-arc spreading and trench subduction of the New England island arc, and developed serious earthquake and earthquake-related soft-sediment deformation. The soft-sediment deformation of Permian in the southern Sydney Basin consist of seismo-cracks, seismo-folds, fluidized veins, sandy volcano, load casts, flame structures, pillow structures, ball structures, pillow beds, slump structures and brecciation. The seismo-cracks and seismo-folds are cracks and folds formed directly by oscillation of earthquake. The pillow beds formed by dehydration and sinking of the sandy beds during earthquake’s oscillation. Fluidized veins and sandy volcano were made by instill into the seismo-fissures of the fluidized sands. The load casts, flame structures, pillow structures and ball structures were formed by sinking and instilling caused from oscillation of earthquake along the face between sandy and muddy beds. The slump structures and brecciation formed by gravity flow related to earthquake. The eismo-fissures, seismo-folds, fluidized veins, sandy volcano, load casts, flame structures, pillow structures, ball structures and pillow beds belong to the autochthonous seismites and slump structures and brecciation to allochthonous seismites.更多还原