福建龙岩中甲锡多金属矿床地质特征及成因机理

GEOLOGY AND METAL LOGENIC MECHANISM OF THE ZHONGJIATIN POLYMETAL LICDEPOSITIN LONGYAN,FUJIAN

中甲锡多金属矿床包括位于不同部位的Ｗ、Ｓｎ、Ｍｏ矿体以及少量的Ｂｉ矿化及黄铜矿化带。它们和外围的Ｆｅ、Ｐｂ、Ｚｎ共同组成一个完整的Ｓｎ、Ｍｏ、Ｗ、Ｃｕ、Ｐｂ、Ｚｎ矿化带。矿区地质调查表明，本矿床在地质特征、成矿物质组分以及围岩蚀变、矿化分带等方面特征明显。通过对矿床地质特征、围岩地层含矿性、稀土元素、微量元素、流体包裹体、稳定同位素的研究以及矿化时代的厘定，认为中甲锡多金属矿床成矿物质主要来源于燕山早期的黑云母花岗岩及其后期分异的石英斑岩体，部分来源于奥陶系罗峰溪群变质石英砂岩；成矿热液早期以岩浆水为主，后期有外来水的加入；Ｒｅ－Ｏｓ同位素测年结果表明，锡多金属矿床成矿年龄为１９３～１９５Ｍａ，属燕山早期阶段成矿；

TheZhongjiatinpolymetalicdepositcoverstheMo,WandSnorebodieshostedindiferentareas.Combi nedwithperipheralPb,ZnandCumineralization,itformsapolymetalicmineralizationarea.Thegeolog y,traceelements,REE,stableisotopes,fluidinclu sionsandRe-Osdatingindicatethattheore-formingmaterialmainlyderivedfromtheearlyYanshannia nbiotitegraniteanditsdiferentialquartzporphyries,partlyfrommetamorphosedquartzsandstone.The ore-formingfluidderivedfrommagmaticwaterintheearlyperiod,andwasthemixtureofmagmaticwater andatmosphericwaterinthelaterperiod.TheRe-Osdatingindicatesanageof193～ 196MathatmeansearlyYanshanianorogeny.Theoredepositrepresentstheproductofhydrothermalfl uidevolutionfromhightomoderatetemperature.