鄂尔多斯西缘牛首山—罗山地区裂变径迹年龄与中生代构造抬升  

Fission track ages and Mesozoic tectonic uplift in the Niushoushan-Luoshan area on the western edge of the Ordos Basin

作　　者：田朝阳 陈虹[2,3] 刘新社 公王斌[2,5] 赵伟波[4] 康锐 TIAN Zhaoyang;CHEN Hong;LIU Xinshe;GONG Wangbin;ZHAO Weibo;KANG Rui(School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Reasearch Center of Polar Geosciences,China Geological Survey,Beijing 100081,China;Institute of Exploration and Development,Changqing Oilfield Company,PetroChina,Xi’an 710018,Shaanxi,China;Key Laboratory of Paleomagnetism and Tectonic Reconstruction of Ministry of Natural Resources,Beijing 100081,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质科学院地质力学研究所,北京100081 [3]中国地质调查局极地地学研究中心,北京100081 [4]中国石油长庆油田公司勘探开发研究院,陕西西安710018 [5]自然资源部古地磁与古构造重建重点实验室,北京100081

出　　处：《地质力学学报》2023年第5期599-617,共19页Journal of Geomechanics

基　　金：中国地质调查局地质调查项目(DD20221644);国家自然科学基金项目(41472195);中国石油前瞻性基础性科技项目(2021DJ2101)。

摘　　要：鄂尔多斯盆地西缘及其邻区经历了中—新生代复杂的构造演化过程,其中生代以来的构造隆升和区域热演化历史研究仍需要进一步的年代学证据。牛首山—罗山地区紧邻鄂尔多斯盆地西缘的冲断带,其中生代的隆升过程对于研究盆地西缘中生代构造事件具有非常重要的意义。文章通过磷灰石裂变径迹(AFT)分析及热史模拟限定牛首山—罗山地区中生代的隆升过程及其时限,结果表明该地区中生代抬升主要发生在中侏罗世(170 Ma)—早白垩世末(110 Ma),罗山地区的抬升(170 Ma)要略早于牛首山地区(160 Ma),这期抬升主要与祁连造山带向北东方向挤出有关。综合分析已有研究成果表明,鄂尔多斯盆地西缘及其邻区中生代抬升的启动时间为晚三叠世,整体可分为两期:第一期抬升发生在晚三叠世(220 Ma)—早侏罗世末期(185 Ma);第二期抬升发生于中侏罗世(175 Ma)—早白垩世末(110 Ma),牛首山—罗山地区的抬升则属于鄂尔多斯盆地西缘第二期抬升的一部分。鄂尔多斯盆地西缘中生代两期构造抬升分别显示出由南向北、由西南向东北方向传递的特征,推测与晚三叠世华北、华南板块碰撞以及中—晚侏罗世拉萨地块向北东方向汇聚有关。The western margin of the Ordos Basin and its adjacent regions have undergone a complex tectonic evolution from the Mesozoic to the Cenozoic era.However,the question of tectonic uplift since the Cenozoic era remains a topic of contention,and the regional thermal evolution history necessitates precise chronological evidence.Situated close to the thrust belt within the western margin of the Ordos Basin,the Niushoushan-Luoshan area holds pivotal significance in unraveling the Mesozoic tectonic events within the basin′s confines.Through a meticulous exploration employing apatite fission track(AFT)analysis and thermal history simulation,this study delineates the Mesozoic uplift sequence and its temporal confines in the Niushoushan-Luoshan area.The results reveal that the Mesozoic uplift within this region predominantly occurred during the Middle Jurassic period(170 Ma)to the end of the Early Cretaceous(110 Ma).Furthermore,we observe a slightly earlier onset of uplift in the Luoshan area(170 Ma)compared to the Niushoushan area(160 Ma).This uplift is primarily attributed to the north-eastward extrusion of the Qilian orogenic belt.Combining our findings with existing research,we propose that the Cenozoic uplift in the western margin of the Ordos Basin and its adjacent areas started during the Late Triassic,comprising two distinct phases:the first phase unfolding from the Late Triassic(220 Ma)to the end of the Early Jurassic(185 Ma),and the second phase occurring from the Middle Jurassic(175 Ma)to the end of the Early Cretaceous(110 Ma);the uplift in the Niushoushan-Luoshan area is part of the second phase of uplift along the western margin of the Ordos Basin.The two Cenozoic tectonic uplift phases along the western margin of the Ordos Basin display characteristics of north-to-south and southwest-to-northeast propagation,respectively.It is inferred to be associated with the Late Triassic collision between the North China and South China blocks,as well as the movement of the Lhasa Block converging toward the northeast du

关 键 词：年代学 裂变径迹 鄂尔多斯 构造抬升 牛首山—罗山 中生代 

分 类 号：P542[天文地球—构造地质学]