北京延庆白河堡水库古火山口机构年代学特征及意义  

U-Pb Geochronology and Its Significances for the Ancient Crate Apparatus by the Baihebu Reservoir in Yanqing, Beijing

作　　者：岳晨曦 于福生[1] 张晓明[2] YUE Chen-xi;YU Fu-sheng;ZHANG Xiao-ming(School of Earth Sciences,China University of Petroleum(Beijing),Beijing 102249;The Fifth Geological Team of Hebei Bureau of Geology and Mineral Resources,Tangshan Hebei 063000)

机构地区：[1]中国石油大学(北京)地球科学学院,北京昌平102249 [2]河北省地矿局第五地质大队,河北唐山063000

出　　处：《四川地质学报》2021年第3期361-365,共5页Acta Geologica Sichuan

摘　　要：通过野外地质调查发现,北京延庆白河堡水库周边出露一完整的古火山口机构,火山口中心岩性为中性粗安岩;精准的LA-ICP-MS锆石U-Pb原位定年显示火山口中心粗安岩形成年龄为131.4±1.5Ma(2σ),代表了火山喷发的年龄;古火山口机构形成于早白垩世,火山岩在岩石地层单位上相当于张家口组;古火山口机构的火山岩可能是克拉通破坏背景下岩石圈减薄、下地壳物质部分熔融的产物。A complete ancient crater apparatus is exposed by the Baihebu reservoir in Yanqing,Beijing.The center of the crater is composed of trachyandesite with zircon U-Pb ages of 131.4±1.5 Ma(2σ).Stratigraphically,the trachyandesite belongs to Lower Cretaceous Zhangjiakou Formation and may be the product of partial melting of the lower crust.

关 键 词：延庆白河堡水库 古火山口机构 LA-ICP-MS U-PB年代学 

分 类 号：P593.3[天文地球—地球化学]