龙门山映秀-北川断裂带擂鼓探槽剖面古地震事件测年  

DETERMINATION OF PALEOEARTHQUAKE EVENTS USING OSL AND AMS^(14)C DATING TECHNIQUES AT THE LEIGU TRENCH ALONG THE LONGMEN SHAN YINGXIU-BEICHUAN FAULT ZONE

作　　者：刘进峰[1] 陈杰[1] 尹金辉[1] 陈立春[1] 卢演俦[1] 杨会丽[1] 

机构地区：[1]中国地震局地质研究所,地震动力学国家重点实验室,北京100029

出　　处：《地震地质》2010年第2期191-199,共9页Seismology and Geology

基　　金：中国地震局地质研究所基本科研业务专项(DF-IGCEA0607110);国家自然科学基金(40802040);中国地震局汶川8.0级地震科学考察项目共同资助

摘　　要：2008年5月12日四川汶川发生MS8.0大地震,形成了200多km长的地震地表破裂带。破裂带的古地震研究对于认识龙门山断裂带的活动习性和大地震的发生规律具有重要的理论和现实意义。文中用光释光(OSL)测年中的校正感量简单多片再生法(SMAR),对映秀-北川地震地表破裂带擂鼓探槽样品进行了光释光测年,并对探槽中含有的炭屑进行了AMS14C测年。样品的光释光年龄和校正的AMS14C年龄吻合,该地区与汶川地震类似规模的上一次古地震事件发生在距今约(2.1±0.2)ka至(1.1±0.2)ka间。Paleoseismic studies conducted along the surface rupture of the Wenchuan earthquake（MS 8.0）of 12th May 2008 provide important information regarding earthquake reoccurrence intervals and slip rates of the Longmen Shan Fault zone.The Leigu trench was excavated along the middle segment of the surface rupture of the Yingxiu-Beichuan Fault zone.Based on the syntectonic sedimentary structure,two earthquake events,including the Wenchuan event,were identified at this site.This study utilizes Optically Stimulated Luminescence（OSL）dating of samples collected from the Leigu trench section,using SMAR（Sensitivity-corrected Multiple Aliquot Regenerative-dose）protocols.AMS^14 C dating was also carried out on charcoal from the same sediments.OSL ages are generally consistent with the calibrated AMS^14 C ages（cal a BP）for the same units.The penultimate earthquake event similar to Wenchuan earthquake scale in this region occurred（2.1±0.2）ka to（1.1±0.2）ka.

关 键 词：汶川MS8.0地震 古地震 光释光测年 

分 类 号：P597[天文地球—地球化学]