冈底斯南缘打加错地区竟柱山组沉积特征及其时代  

SEDIMENTARY CHARACTERISTICS AND AGE OF JINGZHUSHAN FORMATION IN DAJIACUO AREA,SOUTHERN MARGIN OF GANGDISE

作　　者：李鹏举 梁志勇 火久伟 曹勇刚 LI Peng-ju;LIANG Zhi-yong;HUO Jiu-wei;CAO Yong-gang(The Third Institute of Geology and Mineral Exploration,Gansu Provincial Bureau of Geology and Mineral Exploration and Development,Lanzhou 730050,China)

机构地区：[1]甘肃省地矿局第三地勘院,甘肃兰州730050

出　　处：《甘肃地质》2022年第2期16-23,共8页Gansu Geology

基　　金：中国地质调查局“西藏打加错东地区4幅1∶5万区域地质调查”(12120113034400)。

摘　　要：竟柱山组地层出露于西藏昂仁县打加错东地区,是一套以砂岩、砾岩为主的陆相碎屑岩建造,通过野外剖面测制、样品采集、分析测试及同位素年代学研究,分析了竟柱山组地层、沉积环境、沉积相、岩石地球化学特征等,认为该组地层为一套红色磨拉石建造,其形成于打加错断陷湖盆的河流—湖泊相沉积环境。竟柱山组上部安山岩透镜体中锆石U-Pb同位素年龄89.97±0.7 Ma,其地层时代为晚白垩世。Jingzhushan formation outcropped Dajiacuo region in Tibet region in the east,was mainly used for sandstone and conglomerate in terrestrial clastic rock,through our field profile,sample collection,analysis,testing and isotopic chronology research,analyzes the jingzhushan formation,sedimentary environment,sedimentary facies,rock geochemistry characteristics,thought the group formation is a set of red molasse formation,It was formed in the fluvial-lacustrine sedimentary environment of dagako fault depression.Zircon U-Pb isotopic age of the andesite lens in the upper Jingzhushan Formation is 89.97±0.7 Ma,and the stratigraphic age is late Cretaceous.

关 键 词：竟柱山组 沉积特征 冈底斯南缘 打加错 地层时代 

分 类 号：P53[天文地球—古生物学与地层学] P597[天文地球—地质学]