ESR定年:一种确定脆性断层活动年龄的方法原理与应用  

ESR Dating,the Principle and Application of a Method to Determine Active Ages of Brittle Faults

作　　者：杨坤光[1] 梁兴中[2] 谢建磊[1] 杨奎锋[1] 

机构地区：[1]中国地质大学地球科学学院,湖北武汉430074 [2]成都理工大学核材料与核技术系,四川成都610059

出　　处：《地球科学进展》2006年第4期430-435,共6页Advances in Earth Science

基　　金：国家自然科学基金重点项目"大别造山带中生代侵入岩类成因;岩浆动力学及构造体制转换"(编号:40334037);中国石油化工公司重点项目"江南隆起带沉积-构造演化及其对周缘地区油气成藏的控制作用"资助

摘　　要：在浅层低温环境中，脆性断层活动难以生成新的变质矿物，断层的准确活动年龄就难以确定。但在浅层断层活动中，往往伴生有同期生成的石英脉，对石英脉采用热活化电子自旋共振（ESR）测年，能够确定石英脉的生成年龄，从而能提供断层活动的年龄。如果断层带中发育有多期石英脉，通过测定还能提供断层多次活动的年龄。以雪峰山2条断裂带为例，使用ESR定年方法获得了202．3～60．6Ma的地质年龄，并探讨了2条断裂带的演化与区域构造活动的关系，最后对ESR测年的可信性与使用条件进行了讨论。Under shallow and low temperature situation, it is very difficult to form new metamorphic minerals in movement of brittle faults. Therefore we cannot determine the active ages of faults exactly through traditional method. But in activation of shallow faults, there is often homochronous quartz veins formed. By obtaining the ages of quartz veins by thermal activated ESR dating, the active ages of faults can be well supplied. If there were several stages of quartz veins in fault belts, the corresponding active ages of them can also be determined. In this paper, ESR dating method was used to get the active ages of two fault belts in Xuefeng Mountain, with getting a series of age from 202.3 to 60.6Ma. Then, discuss the movement stages of Anhua-Xupu and Zhangjiajie-Huayuan fault belts since Indosinian. Finally, the creditability and condition of applying ESR dating were discussed.

关 键 词：电子自旋共振(ESR)测年 断层 雪峰山 

分 类 号：P541[天文地球—构造地质学]