摘要
鄂尔多斯盆地中生代以来经历多期次构造运动,形成了多期区域性不整合界面。为明确盆地内部存在的不整合界面及其构造响应特征,采用三维地震资料分析的方法并结合前人已有研究资料及钻井资料,识别盆地内部2个三维地震探区的不整合界面并对关键构造事件在盆内不整合界面的响应特征进行研究。结果表明:鄂尔多斯盆地中生代以来经历了四期大规模构造抬升运动,并形成了侏罗系与三叠系、侏罗系内部、白垩系与下伏地层、白垩系与上覆地层间的四期区域性不整合界面;上三叠统延长组和下侏罗统延安组主要以角度不整合接触为主;中侏罗统安定组和下白垩统宜君组以平行不整合为主,部分地区存在微角度不整合;侏罗系内部则同时发育平行不整合及微角度不整合,白垩系与上覆地层主要以平行不整合为主;不整合界面的差异特征反映出印支运动在盆地内部的构造响应西南强、东北弱;燕山运动在盆地内部的构造响应由周缘向内部逐渐减弱。研究结果揭示盆地周缘强烈的挤压构造事件在盆内均有以隆升剥蚀为特征的地震响应,构造变形强度具有明显的减弱,深化了鄂尔多斯盆地内部构造结构的认识。
The Ordos Basin has experienced multi-stage tectonic movements since the Mesozoic,with multi-stage regional unconformity interfaces formed.To clarify the unconformity interfaces within the Ordos Basin and its response characteristics of structure,the unconformity interfaces of two key exploration areas were indentified based on 3D seismic data,with the previous research and rilling data in mind,and a detailed analysis was made of the response characteristics of key tectonic events in the unconformity interface of the basin.The result shows that the Ordos Basin has experienced four stages of large-scale tectonic uplift since the Mesozoic,which have developed regionally extensive unconformities between Jurassic and Triassic stara,intra-Jurassic sequences,Cretaceous and underlying strata,Cretaceous and overlying strata.The Upper Triassic Yanchang Formation and the Lower Jurassic Yan’an Formation are mainly angular unconformity contact;the Middle Jurassic Anding Formation and the Lower Cretaceous Yijun Formation are dominated by parallel unconformity,and there are micro-angle unconformity in some areas.In the Jurassic,the parallel unconformity and micro-angle unconformity are developed at the same time,and the Cretaceous and overlying strata are mainly parallel unconformity.The different characteristics of the unconformity interface in the key exploration area reflects that the tectonic response of the Indosinian movement in the basin is strong in the southwest and weak in the northeast.The tectonic response of the Yanshan movement in the basin is gradually weakened from the periphery to the inside.The research findings indicate that the intense compressional tectonic events along the periphery of the basin are consistently manifested within the basin as seismic responses characterized by uplift and denudation,accompanied by a marked weakening in tectonic deformation intensity.This has deepened the understanding of the internal tectonic architecture of the Ordos Basin.
作者
王慧龙
黄雷
王韶豪
张威
赵俊峰
何发岐
王军
WANG Huilong;HUANG Lei;WANG Shaohao;ZHANG Wei;ZHAO Junfeng;HE Faqi;WANG Jun(Department of Geology,Northwest University,Xi’an 710069,China;State Key Laboratory of Continental Evolution and Early Life,Northwest University,Xi’an 710069,China;Sinopec North China Oil&Gas Company,Zhengzhou 450006,China;The Fifth Oil Production Plant,PetroChina Changqing Oilfield Company,Xi’an 710299,China)
出处
《西安科技大学学报》
北大核心
2025年第3期627-638,共12页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金项目(42272148,42230815)。
关键词
鄂尔多斯盆地
构造事件
三维地震
不整合界面
Ordos Basin
tectonic event
three-dimension seismic
unconformity interface
