摘要
褶皱冲断带-前陆盆地系统普遍经历复杂浅表构造剥蚀-沉积作用过程,且受控于岩石地层展布和先存构造等因素,从而具有复杂的三维空间构造变形特征与演化过程。本文以青藏高原东缘龙门山褶皱冲断带-川西前陆盆地系统为原型,基于砂箱物理模拟实验手段,设计了先存断裂和软弱岩层为控制因素的实验模型。对实验结果的构造变形特征进行解剖,探讨前陆冲断带不同位置的构造演化序列和埋深-沉降过程。研究结果表明:构造剥蚀-沉积作用导致冲断带后缘断层多期次活化,先存断层周缘区域属于构造薄弱带,在晚期构造挤压过程中先存断裂优先发生活化并形成反转构造。软弱滑脱层会导致应变集中滑脱效应,位于滑脱层附近的先存断层带更易形成复杂多样的反转构造。前陆冲断带不同位置的剥蚀抬升-埋深沉降史具有显著的差异性,冲断带上盘物质伴随挤压冲断发生微弱的埋深沉降,前陆盆地在冲断负载过程中发生快速和持续的埋深增温过程。龙门山山前隐伏构造带存在有利于油气聚集的反转冲起构造变形带。
Fold-thrust foreland basin systems generally undergo a complex shallow tectonic denudation-deposition process that is controlled by factors such as rock stratum distribution and preexisting structure,imparting them with complex three-dimensional spatial structural deformation characteristics and evolutionary processes.In this paper,the Longmenshan fold-thrust belt in the western Sichuan foreland basin system,located on the eastern margin of the Qinghai-Tibet Plateau,is taken as the study object.Based on sandbox analog experiments,an experimental model with preexisting faults and weak rock strata as controlling factors was designed.The structural evolution sequence and subsidence history of different tectonic belts were analysed and discussed.The results show that erosion and sedimentation obviously leads to multistage activation of the boundary faults of the thrust belt,and the area around the preexisting faults is a structurally weak zone.During the compression process,preexisting faults are reactivated to accommodate inversion structures.The existence of a weak detachment layer leads to decollement,which in turn facilitates the formation of diverse inversion structures.The erosion and sedimentation histories of different tectonic belts in the fold thrust belt are significantly different.The hanging wall material of the thrust belt demonstrates a weak buried depth,arising from thrust deformation,and a rapid and continuous burial process occurred during the thrust load process of the foreland basin.The buried structural belt in the frontier of the Longmenshan Mountain has an inverted structural deformation zone that facilitates oil and gas accumulation.
作者
邓宾
刘恣君
马华灵
胡欣
郭虹兵
张本健
张旋
何宇
涂国煜
何泽亮
张小兵
DENG Bin;LIU Zijun;MA Hualing;HU Xin;GUO Hongbing;ZHANG Benjian;ZHANG Xuan;HE Yu;TU Guoyu;HE Zeliang;ZHANG Xiaobing(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;Oilfield Technology Division of China Oilfield Services Co.,Ltd.,Langfang 065201,China;PetroChina Southwest Oil&Gasfield Company,Chengdu 610050,China)
出处
《成都理工大学学报(自然科学版)》
北大核心
2026年第1期1-17,共17页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
国家自然科学基金(42572160)
四川省科技厅创新团队项目(2022JDRC0001)。
关键词
褶皱冲断带
青藏高原东缘
剥蚀-沉积作用
先存断层
反转构造
埋深-沉降史
fold-thrust belt
eastern margin of the Tibetan Plateau
erosion and sedimentation
preexisting fault
inversion structure
subsidence history
