摘要
垭紫罗断裂带深部构造分段特征及构造变换的研究对其两侧盆地的构造化演化、沉积充填、油气成藏的差异分析均有重要意义。运用重、磁、电、震等资料的综合分析表明,垭紫罗断裂带走向上可分为3段,具有由西北段(威宁段)的4条深断层转换为中段(关岭段)2条深断层、至东南段(紫云段)时演变为1条深断层的构造变换特征,且正断层的主体倾向亦由WS倾变换为NE倾;同时,该断裂带对古生代沉积具有由西北段向东南段迁移的控制作用,即西北段控制了志留纪槽盆的沉积范围,西北段至中段则限定了泥盆系向黔中隆起的超覆边界与石炭纪深水槽盆沉积区,东南段则为二叠纪深水沉积带。垭紫罗断裂带中段(关岭段)的构造演化经历了泥盆纪初始伸展期、石炭纪断陷期、二叠纪裂谷期、三叠纪构造反转期和侏罗纪以来的陆内收缩期等5个阶段,其变形样式表现为晚古生代地堑的边界断层发生反转而形成的扇形背冲结构,构造剖面的缩短率高达51.68%。
The study on deep structural segmentation and transformation of the Yaziluo fault zone is of great significance for understanding the tectonic evolution,sedimentation and hydrocarbon accumulation of the basins on its two sides.Based on comprehensive analyses of gravity,magnetic,electric and seismic data,this paper divided the Yaziluo fault zone into three segments along its strike.The structural transformation is characterized by four deep faults in the northwest segment (Wei-ning segment),two deep faults in the middle segment (Guanling segment),and one deep fault in the southeast segment (Ziyun segment).The major dip direction of the normal faults changes from southwestward to northeastward.Meanwhile,the Yaziluo fault zone controls the migration of the Paleozoic deposits from the northwest segment to the southeast segment,i.e.the northwest segment controls the limit of the Silurian deposition,the northwest to the middle segments control the Devonian onlap boundary to the Qianzhong uplift and the Carboniferous deep basin sedimentation,and the southeast segment controls the Permian deep-water sedimentary belt.The tectonic evolution of the middle segment (Guanling segment) of the Yaziluo fault zone experienced five stages,namely the initial extension during the Devonian,the extensional faulting during the Carboniferous,the rifting during the Permian,the tectonic inversion during the Triassic and the inland contraction since the Jurassic.Its deformation style is characterized by a fan-shaped back thrusting structure resulted from reversing of the boundary faults of the Late Paleozoic graben.The shortening rate of structural profile is up to 51.68%.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2013年第2期220-228,共9页
Oil & Gas Geology
基金
国家科技重大专项(2008ZX05005)
中国石化勘探南方分公司项目(G0800-06-ZS-157)
关键词
分段特征
构造变换
深部构造
垭紫罗断裂带
segmentation characteristics
structural transformation
deep structure
Yaziluo fault zone