四川昔格达组地层的石英Ti心ESR测年及与磁性地层剖面的对比  

Quartz Ti-center in ESR dating of Xigeda formation in Sichuanand contrast with magnetic stratigraphic profiles

作　　者：王萍[1] 李建平[1] 王建存[1,2] 刘春茹[1] 韩非[1] 高璐[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 [2]中国地质大学,北京100083

出　　处：《核技术》2011年第2期111-115,共5页Nuclear Techniques

基　　金：国家自然科学基金(40472090);中国地震局地震动力学国家重点实验室(LED2008A02)资助

摘　　要：昔格达组是我国西南地区著名的晚新生代河湖相沉积地层,广泛分布于大渡河、安宁河和金沙江等河谷中,其形成年代主要依据沉积剖面的磁性地层学研究结果,约4.18–1.78 Ma。对四川昔格达组几个典型剖面中砂样品进行石英Ti心ESR测年,结果显示为中更新世时期距今数十万年期间的沉积。将ESR年龄标定在磁性地层剖面上,显示以正极性时为主的昔格达组地层可划归为布容时(Brunhes Chron)。Xigeda formation is a famous fluvial-lacustrine sedimentation formed in late cenozoic in southwest China, distributed in the valley of Dadu River, Anning River, Chin-sha River etc. The age of Xigeda formation, ranges between 4.18 and 1.78 Ma BP, depending on the magnetic stratigraphy research of the stratigraphic section. Quartz Ti-center in ESR dating of sand samples from several typical sections of Xigeda formation in Sichuan shows that they are sediments in mid-pleistocene. Comparing the ESR ages and mainly normal polarity, Xigeda formation can be confirmed in Brunhes epoch according to magnetic stratigraphy.

关 键 词：昔格达组 ESR Ti心 磁性地层 堰塞湖 

分 类 号：P597.3[天文地球—地球化学]