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在塔里木盆地塔中隆起与满加尔坳陷结合部——顺托果勒地区的深钻井岩心中,发现了大量早中志留世软沉积变形构造。其中主要包括液化砂岩脉、液化角砾岩、触变底劈构造、触变楔、负载构造、球-枕构造和复合混插构造等。通过系统地观察软沉积变形构造的岩石组成、构造形貌及样式、垂向分布的循环性、横向分布的延展性、沉积环境及与古活动断裂的关系,确定其为震积岩。结合该区断裂早中志留世的发育特征,推测发震断裂主要可能是塔中隆起与满加尔坳陷结合部的北东向走滑逆冲断裂以及北西向剪切拉张断裂。在早志留世柯坪塔格组沉积时约4 Ma中最少发生了26次古地震事件(震级M>5)。这些古地震记录不仅反映了研究区志留纪构造的活动性,也是弥补主构造运动中高频次构造事件脉动性、循环性的重要证据,为重建中古生代的古构造提供新的线索。
A large number of early Silurian soft sedimentary deformations have been found in the deep drilling cores in the junction of the Tazhong uplift and Manjar depression in the Tarim Basin. Mainly include liquefaction sandstone veins, liquefaction breccias, thixotropic bottom split structure, thixotropic wedges, load structure, ball-pillow structure and composite mixed insertion structure. By systematically observing the rock composition, tectonic morphology and pattern of the soft sedimentary deformation structure, the cyclic distribution of the vertical distribution, the extensibility of the lateral distribution, the sedimentary environment and the relationship with the paleo-active faults, it is confirmed as seismites. Based on the development characteristics of the Early Middle-Middle Jurassic faults in this area, it is speculated that the seismogenic faults may be mainly the NE-trending strike-slip thrust faults and the NW-trending shear tension faults at the junction of the Tazhong uplift and Manjar depression. At least about 4 Ma pale-earthquakes occurred in about 4 Ma during the deposition of the Early Persecuted Kepingtage Formation (magnitude M> 5). These paleoseismic records not only reflect the activity of the Silurian tectonics in the study area but also are important evidences to make up for the pulsation and circulation of high-frequency structural events in the main tectonic movement and provide new clues for rebuilding the Paleozoic paleo-tectonics.