The Zhaceqiao gold-polymetal deposit was discovered recently in the Jiangnan Transitional Zone.In order to obtain the ore-forming age,sericite was separated from the altered granite porphyry which hosts the gold deposit.40Ar-39Ar analyses of sericite in gold ore yield spectrum age of 156.9±1.6 Ma with the isochron age of 152±28 Ma.The spectrum age of sericite in altered granodiorite porphyry is 142.1±l.3 Ma with the isochron age of 137±13 Ma.The homogenization temperature of fluid inclusions in quartz from the Niutougaojia and Chengtan ore sections is c.a.160 ℃.The H-O isotopic compositions indicate that the ore-forming fluids mainly come from magmatic hydrothermal sources.Integrating with regional studies,the Zhaceqiao gold deposit is predominantly characterized by shallow,low temperature and epithermal,similar to Carlin-like type gold deposit.The Zhaceqiao gold deposit was formed in Yanshanian through multi-stage superimposition.The gold mineralization was related to the ductile-brittle compressional tectonic deformation and alteration in middle Jurassic to gold,while the polymetallic mineralization was related to the Late Jurassic-Early Cretaceous igneous activity,and the epithermal mineralization in the middle and late stage of the Early Cretaceous.%查册桥金矿是近年来在江南过渡带发现的一个金多金属矿床,本文对该矿床与矿化有关的蚀变花岗闪长斑岩中绢云母进行了40Ar-39Ar年龄测试,获得蚀变岩金矿石绢云母坪年龄156.9±1.6 Ma,等时线年龄152±28Ma和矿化强蚀变花岗闪长斑岩绢云母坪年龄142.1±1.3 Ma,等时线年龄137±13Ma.程檀矿段与牛头高家矿段流体包裹体均一温度为160℃左右,氢氧同位素特征显示成矿热液以岩浆热液为主.结合本区及邻近矿区相关研究成果,本区金矿主要为浅成、低温型,成矿物质和热液具有多来源特征,原生金矿以微细粒浸染型为主,具类卡林型金矿矿化特征,其年龄值分别对应于燕山期不同阶段构造活动和成岩成矿作用时代,其成矿过程经历了中侏罗世韧-脆性挤压构造变形和蚀变、矿化,晚侏罗世-早白垩世早期与岩体侵入相关的金多金属矿化,以及早白垩世中、晚期浅成低温热液成矿作用.
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