Syn-Faulting Calcite Ages:Constraint for the Late Mesozoic Deformation of the Ningzhen Mountain,Eastern China  

作　　者：Jinbao Su Hongbing Tan Yuexing Feng Guoxing Qin 

机构地区：[1]College of Oceanography,Hohai University,Nanjing,210098,China [2]School of Earth Sciences and Engineering,Hohai University,Nanjing,210098,China [3]School of Earth Sciences,The University of Queensland,Brisbane,QLD,4072,Australia

出　　处：《Journal of Earth Science》2021年第6期1485-1495,共11页地球科学学刊（英文版）

基　　金：financially supported by the Natural Science Foundation of China(No.41872074);the Fundamental Research Funds of the Central Universities;China(No.2013B200202021)。

摘　　要：It is difficult to date a brittle fault because of the absence of effective dating methods.Recently,calcite U-Pb dating has drawn the attention of many researchers and has been successfully applied to constrain the age of brittle deformation.The South China Block(SCB)has experienced multiphase deformations characterized by widespread brittle faults and folds,which has led to significant debate on the Mesozoic dynamic mechanism and deformational phases.A syn-faulting calcite vein that occurred in the Permian limestones of the Ningzhen Mountain region was analyzed using U-Pb dating and geochemistry techniques in this paper.The U-Pb dating results display multiphase activities with two mixed ages of 109.9±5.8 Ma(MSWD=46,n=231)and 117.2±2.4 Ma(MSWD=3.6,n=150).The age of 117.2±2.4 Ma likely represents the timing of the brittle faults.Trace elements and rare earth elements data indicate that these fault-related calcites are mainly derived from host limestones and unrelated to Cretaceous magmatic activity.These faults formed in a tectonic reactive period and dormant time of the adakitic magma in the Lower Yangtze region.

关 键 词：U-Pb dating CALCITE South China Block brittle fault adakitic rock 

分 类 号：P534.5[天文地球—古生物学与地层学] P542[天文地球—地质学] P597.3