Geochronologic and isotope geochemical constraints on magmatism and associated W-Mo mineralization of the Jitoushan W-Mo deposit,middle-lower Yangtze Valley
作者单位：Key Laboratory of Mineral ResourcesInstitute of Geology and GeophysicsChinese Academy of Sciences Key Laboratory of Lithospheric EvolutionInstitute of Geology and GeophysicsChinese Academy of Sciences CODES ARC Centre of Excellence in Ore DepositsUniversity of Tasmania
会议名称：《中国科学院地质与地球物理研究所2012年度（第12届）学术年会》
会议日期：2013年
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 Knowleage Innoyation P roiect ofthe Chinese Academy ofSciences(grant nos.KZCX1-YW-15- 3 and KZCX2-YW-Q04-08) the Key Laboratory of Mineral Resources of IGGCAS
关 键 词：middle-lower Yangtze Valley Jitoushan W-Mo deposit skarn-type W-Mo deposit SIMS U-Pb age Re-Os isotopic age southern Anhui Province
摘 要：The Jitoushan W-Mo ore body is a typical skarn-type deposit with the potential for porphyry Mo mineralization at depth. As it is newly discovered,only a few studies have been conducted on the geochronology and ore genesis of this *** ore district consists of Cambrian to Silurian sedimentary and low-grade metasedimentary strata,intruded by granodiorite, diorite porphyry,granite porphyry,and quartz *** W-Mo ore bodies are hosted in the contact zone between the granodiorite and Cambrian limestone *** the granodiorite near the contact zone,quartz vein type and disseminated sulphide mineralization are well *** Mo-bearing granite porphyry has been traced at depth by *** results reveal two discrete magmatic events at ca.138 and ca.127 Ma in the study *** molybdenite Re-Os isochronal age of 136.6±1.5 million years is consistent with the first magmatic *** zircon Hf isotope(ε(t) =—12.55-3.91),sulphide isotopes( δS = 3.32-5.59‰),and Re content of molybdenite(Re = 6.424-19.07μg) indicate that the ore-forming materials were mainly derived from the deep *** regional tectonic system switched from a Late Jurassic transpressive regime to an earliest Cretaceous extensional regime at ca.145 Ma,and at ca.138 Ma,the Jitoushan W-Mo deposit formed in an extensional setting.