Constraints on the late Mesozoic regional angular unconformity in West Liaoning-North Hebei by LA-ICP-MS dating

作     者：Hong Zhang~(a,b,*) Wenmin Guo~a Xiaoming Liu~b a College of Mechanical and Energy Engineering,Jiangsu Polytechnic University,Changzhou 213016,China b Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China 

作者机构：College of Mechanical and Energy Engineering Jiangsu Polytechnic University Changzhou 213016 China Key Laboratory of Continental Dynamics Department of Geology Northwest University Xi’an 710069 China 

出 版 物：《Progress in Natural Science:Materials International》 (自然科学进展·国际材料(英文))

年 卷 期：2008年第18卷第11期

页      面：1395-1402页

核心收录：

学科分类：070902[理学-地球化学] 0709[理学-地质学] 07[理学] 

基　　金：supported by“the 111 Plan of University and College(B07039)” the National Natural Science Foundation of China(Grant No.90714010) 

主　　题：Dating LA-ICP-MS Angular unconformity Interface of tectonic transformation West Liaoning-North Hebei 

摘      要：The angular unconformity between the Tuchengzi Formation and the Zhangjiakou Formation in the Chengde area is commonly regarded as the direct evidence of boundary between Jurassic and Cretaceous systems,and as the evidence of tectonic transformation interfaces in Mesozoic Era in the West Liaoning-North ***,the lower boundary age of the Zhangjiakou Formation in the Chengde was to be thought about 135 Myr in the *** on the detailed study and systematic sampling in Yixian-Beipiao,Lingy- uan,Chengde and Luanping areas in the field,the authors obtained the following isotopic ages by means of LA-ICP-MS dating:In the Lingyuan area,the Zhangjiakou Formation and the Yixian Formation are in angular unconformable contact;the age range of the Zhangjiakou Formation volcanic rock is from 133 to 130 Myr(seven samples),and that of the Yixian Formation volcanic rock is from 126 to 121 Myr(eleven samples).In the Luotuoshan of Chengde,the Tuchengzi Formation and the Zhangjiakou Formation are in angu- lar unconformable contact;the age at the lower Zhangjiakou Formation is about 124 Myr(one sample),which reflects that the age range of the lower Zhangjiakou Formation is from 129 to 124 Myr combined with the previous *** the Luanping basin,there is the larg- est sediment gap in upper Mesozoic,whose lower boundary age is confined in 131 to 130 *** the Yixian-Beipiao area,the second Member of the Yixian Formation,making up more than 3/4 thickness of the Yixian Formation,was formed in 126 to 119 Myr,and the age of the Yixian Formation at the bottom is about 132 ***,the upper boundary age of the Tuchengzi Formation is about 136 Myr in the West Liaoning-North Hebei *** on the above isotopic data combined with the geological characteristics in the field in the West Liaoning-North Hebei region,it reflects that there was a widespread tectonic event in the period of 136 to 126 Myr (mainly in 130-126 Myr)in the West Liaoning-North Hebei,and it formed the