【摘要】 在区域构造背景研究和岩心观察的基础上,在柴达木盆地西南缘新近纪地层中识别出与地震沉积有关的软沉积物变形构造。软沉积物变形构造包括液化砂岩脉、泄水构造、重荷模、火焰构造、震积砂枕、砂球构造、枕状层、层内错断、地裂缝、串珠状构造、震褶层、混合层及地震角砾状构造等。液化砂岩脉有喉道状、脉络状、飘带状、尖突状及"V"字形五种,主要是由振动流体化作用、振动液化挤压作用和振动拉张裂缝充填作用形成的;重荷模、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;地裂缝、层内错断、震褶层是地震颤动直接引起的断裂、错断和褶皱;枕状层是地震振动引起的砂层脱水、下沉、变形形成的;混合层构造的完整性取决于地震强度和地震持续时间;地震角砾状构造是由地震振动使原始沉积层断裂形成的自碎屑角砾、脆性角砾和塑性角砾组成。该成果从沉积学角度证明了新近纪是昆仑山造山带北侧断裂活动较强烈时期,也为柴达木盆地新生代构造演化研究提供了依据。地震作用极大地提高了储层的渗透率,改善了油气储层的储集物性。更多还原

【Abstract】 Based on studies of regional tectonic setting and observation of drilling cores, soft-sediment deformation structures of Neogene related to earthquake are recognized in the southwestern margin of the Qaidam Basin. The soft-sediment deformation structures consist of liquefied sandstone vein,water escape structures,load casts,flame structures,pillow structures,ball structures,pillow beds,micro-faults, seismo-cracks,pinch and swell structures,seismo-folds, mixed layers structures and seismic brecciated structures. There are five kinds of sand dikes, such as throat-like sand dikes, venation-like sand dikes, belt-like sand dikes, upward wedge sand dikes and v-shape sand dikes. They are caused by shaking-fluidization, shaking-liquefaction-pushing and after shaking-pulling soft-sediments filling in cracks. The load casts,flame structures,pillow structures and ball structures are formed by sinking and instilling caused from oscillation of earthquake along the face between sandy and muddy beds. The seismo-cracks,micro-faults and seismo-folds are cracks, faults and folds formed directly by oscillation of earthquake. The pillow beds form by dehydration, sinking and deforming of the sandy beds during earthquake′s oscillation. The integrity of mixed layers structure depends on the magnitude and duration of earthquake. The seismic brecciated structures are made up of autoclastic breccias, plastic breccias and brittle breccias formed by the cracking of basal undisturbed laminate bed because of oscillation of earthquake. The discovery demonstrates that the movement of earthquake was violent on the time of Neogene in the north of Kunlun Orogenic Belt from sedimentology, and it provides a theoretical foundation for the tectonic evolution studies of the Qaidam Basin. Seismic events affect greatly on the physical properties of reservoirs, and the permeability of reservoirs can be improved obviously.更多还原