南北构造带北部“古脊梁”演化过程探讨  

Tectonic evolution of"the archaic uplift"in the northern North-South Tectonic Belt

作　　者：赵晓辰 柯先启 白杰 ZHAO Xiaochen;KE Xianqi;BAI Jie(College of Geology and Environment, Xi′an University of Science and Technology, Xi′an 710054, China;No.5 Oil Production Plant, PetroChina Changqing Oilfield Company, Xi′an 710200, China;Petroleum Exploration Company, Shaanxi Yanchang Petroleum (Group) Co., Ltd., Yan′an 716000, China)

机构地区：[1]西安科技大学地质与环境学院,陕西西安710054 [2]中国石油长庆油田分公司第五采油厂,陕西西安710200 [3]延长石油(集团)有限责任公司油气勘探公司,陕西延安716000

出　　处：《西北大学学报（自然科学版）》2020年第6期1015-1026,共12页Journal of Northwest University（Natural Science Edition）

基　　金：国家自然科学基金青年基金资助项目(41802119);中国博士后科学基金资助项目(2019M663779);陕西省科学基金资助项目(2019JQ-88)。

摘　　要：选择“古脊梁”为研究对象,在综合前人研究的基础上,对研究区内蓟县系奥陶系的展布特征和接触关系、周邻沉积区碎屑组分以及低温热年代学资料等进行系统分析,进而探讨“古脊梁”的演化过程。研究表明,“古脊梁”地区广泛存在的古老地层的陡立和各期地层间的高角度不整合接触,说明“古脊梁”在地质历史时期经历了多期次的构造隆升作用;延长组下部(长8~长10)和中上部(长1~长7)在沉积特征和碎屑组分上的明显差异则表明,“古脊梁”在长8末期受到印支运动的强烈影响而发生了显著的构造隆升;“古脊梁”周邻的裂变径迹年龄统计结果进一步反映出,“古脊梁”在中—新生代期间经历了多期次的构造隆升作用。研究认为,“古脊梁”发生了多期构造隆升事件,经历了复杂的、动态的构造演化过程,表现出构造活跃期与构造平静期交替出现的特征:在构造活跃期内,发生强烈隆升,造成两侧沉积域的分隔;在平静期内,隆升作用减弱,广泛接受沉积,早期形成的山体被逐渐夷平。To discuss the tectonic evolution of this area,the strata distribution and contact relationship,detrital components,and low temperature thermochronology data are analyzed.The steep ancient strata and angle unconformity between different strata indicate"the archaic uplift"experienced multiple periods of tectonic uplift.The obvious difference in sedimentary and detrital components between the lower Yanchang Formation(Chang 8~10)and upper Yanchang Formation(Chang 1~7)suggest"the archaic uplift"was significantly uplifted by the indosinian movement at the end of Chang 8.The fission track ages further reflect that"the archaic uplift"experienced multiple periods of uplift during the Meso-Cenozoic.In general,"the archaic uplift"has complicated tectonic evolution and multi-phase tectonic uplift,showing the characteristics of tectonic active and calm period appear alternately.

关 键 词：“古脊梁” 南北构造带北部 隆升 动态演化 

分 类 号：P542[天文地球—构造地质学]