Geology,isotopes and geochronology of the Caijiaping Pb-Zn deposit in the North Wuyi area,South China:Implications for petrogenesis and metallogenesis
作者单位：Key Laboratory of Mineral ResourcesInstitute of Geology and GeophysicsChinese Academy of Sciences School of the Earth Sciences and ResourcesChina University of Geosciences Department of GeoscienceUniversity of Iowa Institute of GeomechanicsChinese Academy of Geological Sciences
会议名称：《中国科学院地质与地球物理研究所2014年度（第14届）学术年会》
会议日期：2015年
学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程]
基 金：financially supported by National 973 Project of China(Grant No.2012CB416601) National Natural Science Funds Program of the People’s Republic of China(Grant No.40772134)
关 键 词：S-Pb-Hf isotopes Zircon U-Pb dating 40Ar/39Ar dating Ore genesis Wuyi metamorphosed basement
摘 要：The Caijiaping Pb-Zn deposit is a recently discovered subvolcanic hydrothermal deposit in the North Wuyi *** mineralization is generally distributed at the contact of rhyolite porphyry and sandstone,and in the interlayer crushed zone of Early Jurassic *** minerals in this deposit mainly consist of abundant sphalerite,galena,pyrite and ***,chloritization and sericitization are widely developed and closely related to the Pb-Zn *** δS values of early dark brown sphalerite(marmatite),main-stage sphalerite and galena(- 1.1-2.5‰ average 0.83‰) suggest that the sulfur was mainly sourced from a magmatic *** isotope ratios in the sulfide minerals,rhyolite porphyry and sandstone are relatively homogeneous(Pb/Pb = 17.786-18.612,Pb/Pb = 15.504-15.635,Pb/Pb = 38.115-38.798),and are compatible with metamorphic rocks of IVIesoproterozoic Zhoutan Group(Wuyi metamorphosed basement).Early Jurassic sandstone,deposited in an active continental margin or continental arc setting,exhibits low textural maturity and displays geochemical similarities to the Zhoutan *** rhyolite porphyry,with features of volcanic arc granite,also shows an affinity with the Zhoutan *** zircon U-Pb dating shows that the rhyolite porphyry was emplaced at 156.0 ± 1.2 Ma,indicating that Caijiaping mineralization formed later than 156 *** isotope compositions of the rhyolite porphyry[ε(t) = —14.3 to —8.5,average —10.6]imply that it was mainly derived from reworking of ancient *** feldspar selected from felsic veins within the ore-cutting F4 fault yields a Ar/Ar age of 120.0 ± 4.0 Ma,indicating that the Pb-Zn mineralization formed before120 ***,the age of mineralization is bracketed between 156 and 120 *** with regional geological information,we propose that the Caijiaping mineralization mainly formed from magmatic hydrothermal processes in a regionally extensional setting,and the Wuyi metamorphosed basement