南北构造带北部香山地区中-新生代构造抬升事件  

Mesozoic-Cenozoic tectonic uplift events of Xiangshan Mountain in northern North-South Tectonic Belt,China

作　　者：赵晓辰[1] 刘池洋[1] 王建强[1] 赵岩[1] 张东东[1] 王磊[1] 邓煜[1] 郭佩[1] 

机构地区：[1]大陆动力学国家重点实验室西北大学地质学系,西安710069

出　　处：《岩石学报》2016年第7期2124-2136,共13页Acta Petrologica Sinica

基　　金：国家自然科学重点基金项目(41330315;91214301);中国地质调查局专项项目(12120113039900;12120114009201);西北大学大陆动力学国家重点实验室科学技术部专项联合资助

摘　　要：南北构造带北部位于鄂尔多斯地块和阿拉善地块,秦祁褶皱造山带和兴蒙褶皱带四大构造单元的结合交汇部位,演化历史复杂。本文以南北构造带北部香山地区为研究对象,探讨该区中-新生代的隆升过程和阶段。对采自香山地区的9件样品分别进行了锆石、磷灰石裂变径迹测年及热历史模拟分析。香山地区的裂变径迹年龄主要分布在4个区间,对应地质时代分别为晚三叠世末-早侏罗世、晚侏罗世末-早白垩世初、晚白垩世和始新世,反映出香山地区在这4个时期内发生了明显的冷却事件。而这4期冷却抬升事件与区域构造背景及野外地质特征均有很好的响应关系。同时热历史模拟表明,香山地区晚白垩世以来整体上经历了2期快速隆升事件,其中始新世的快速隆升主要是该区对鄂尔多斯地块新生代周缘裂陷解体事件的响应。值得注意的是,香山地区并未反映出8Ma左右的快速隆升,说明青藏高原隆升对该区的影响是较为有限的。The North-South Tectonic Belt is located in the conjunction region among the Ordos Block,the Alxa Terrane,the Qin-Qi Orogenic Belt and the Xing-Meng Orogenic Belt,which has a special tectonic location and complex evolutionary history. This paper is designed to take the Xiangshan Mountain located in the north segment of the North-South Tectonic Belt as the study area for discussing its Mesozoic-Cenozoic uplifting history. Apatite and zircon fission track dating and time-temperature thermal history modeling are carried to analyze on nine samples in the Xiangshan Mountain. The results indicate that the Xiangshan Mountain underwent four cooling events which occurred in Late Triassic-Early Jurassic,Late Jurassic-Early Cretaceous,Late Cretaceous and Eocene,respectively. The four cooling events have a good response to the regional background and field geology. In addition,the thermal history modeling indicates that the uplifting process of the Xiangshan Mountain can be divided into two stages of rapid uplifting events since the Late Cretaceous,one occurred in the Eocene was the response of the Ningnan area to the Cenozoic peripheral rifting and breakup event of the Ordos Block. It is worth noting that the analysis results do not reflect the rapid uplift of the study area at about 8Ma,indicating the uplift of the Tibet Plateau had a limited impact on the Xiangshan area.

关 键 词：裂变径迹 热历史 香山 中-新生代 隆升期次 

分 类 号：P542[天文地球—构造地质学]