摘要
云南省洱源县构造上位于青藏高原东南缘,发育多条区域性主干断裂,具有复杂的构造特征及多期演化阶段。为深入分析洱源县断裂和褶皱构造的性质及其空间展布特征,本文通过野外地质调查和ArcGIS软件,探讨了该县内构造变形的空间展布规律。研究结果表明:(1)洱源县域内多条区域性断裂具有多期性、多方向性、多极性等特征,并且褶皱构造形成和演化与主干断裂的演化密切相关;(2)洱源县具有东西分带和南北分段差异构造变形特征,其中分带性是指由北北西走向的多条断裂带自西至东构造扩展而在地表所表现出来的分带特征,分段性则反映了新生代以来多条北东东走向的后期断裂对早期构造进行错断和改造之后而在平面上所展现的分布规律;(3)上述差异构造变形特征的形成是由于区域应力场在中新世发生变化所致,应力场由中新世之前的左行压扭性构造应力转为右行张扭性构造应力。
Eryuan County,Yunnan Province is tectonically located on the southeastern edge of the Qinghai-Tibet Plateau,with multiple regional main faults,complex structural features,and multiple stages of tectonic evolution.In order to intensively analyze the properties and spatial distribution characteristics of faults and folds in Eryuan County,this article explores the spatial distribution patterns of tectonic deformation in the county through field geological surveys and ArcGIS software.The research results indicate that:(1)Multiple regional faults in Eryuan County have characteristics of multi-phase,multi-directional,and multipolar,and the formation and evolution of folds are closely related to the evolution of the main faults.(2)Eryuan County has the characteristics of east-west zonation and north-south segmentation.Zonation refers to the zoning characteristics exhibited on the surface by the extension of multiple faults from west to east in a northwest trend,while segmentation reflects the distribution patterns exhibited on the plane after the dislocation and transformation of former structures by multiple later faults in a northeast direction since the Cenozoic.(3)The formation of the above differential tectonic deformation characteristics is due to the change of regional stress field in Miocene,and the stress field has changed from left-lateral compressive torsional tectonic stress before Miocene to right-lateral tensile torsional tectonic stress.
作者
金文正
JIN Wen-zheng(China University of Geosciences,Beijing 100083,China;Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism,Ministry of Education,Beijing 100083,China)
出处
《河北地质大学学报》
2024年第2期41-46,共6页
Journal of Hebei Geo University
基金
云南省科技计划项目(202302AF080001)
国家自然科学基金项目(41002072)。
关键词
差异构造变形
分带
分段
褶皱
断裂
洱源
differential tectonic deformation
zonation
segmentation
fold
fault
Eryuan
