胶莱盆地含矿系与金矿关系初探

在胶莱盆地内,由富Au和富C_有机的岩石组成的含矿系中发现金矿床。含矿系属下白垩统莱阳群底部,与胶莱盆地第1生油层同层位。金矿呈层状、似层状产于含矿系层间破碎带中。金属矿物组合:金银矿物一闪锌矿一方铅矿一赤铁矿一黄铁矿一磁铁矿一黄铜矿;成矿元素为Au一Ag-Zn-Pb-Cu-Fe。矿石中流体包裹体成分主要是H₂O、CO₂、CH₄、C₂H₆、CH₈、CH₂=CH₂:S及N.矿床的形成经历了矿源层形成一成岩改造一油油气运移富集一油田卤水改造的低温改造过程。胶莱盆地特殊的形成和演化条件使该类型层控金矿床具较大的找矿前景。

PRELIMIN ARY STUDY ON RELATIONSHIP BETWEEN THE ORE-BEARING SYSTEM AND GOLD DEPOSIT IN JIAO-LAI BASIN

The gold deposits were discoveed in ore-bairing system of Jiao-Lai bash.The ore-bearing systim is corapood of gold-rich.rock and organic,carbon-rich rock.The ore-bearing system is developed at thc botton of Cretaceous Laiyang group,the same bed as the first oil-geaendng stmtum of the basin.The ore-tcaring systam is disvibuted in northeast and southwot of the basin.The average gold contentis174.86mg/g of 171 sunples in the region.The ore-bearing systxn coatdn high Au,Ag,Pb,Zn,Cu,Fe.The oontmts of Au,Ag,Pb,Zn have dimct propordon rdadon with organic carbon and sulfur in the ore-bearing systim.The gold deposits.are formed ia beded and qua-si-bded intalayer fractured zone ofthe ore-bearing system The assemblage of ore-form-iag elements is Au-Ag-Zn-Pb-Cu-Fe.The assemblage of metaUic minenl is goldargemtid- sphalaite-galena-hemadte-phdte-magnedte-chalcopldte.The essential compositins offluid inclusion are H₂O,CO₂,CH₄,C₂H₆,C₃H₈,CH₂=CH₂,S and N.The processes of the deposit fornation are:fonnation of source led-diagenetic reformationgas and oil.formation transposition and concentration-oilfield brine rdonaadon.That is a lower tampemture ore-reforming stntabound deposit.The Jiao-Lai basin was formed in lower Cretaceous as a fault basin.Duringtheinidalmo- tion preiod of the basin,it was only a local water body in Mupin-Ldyang and Wulian-Zhucheag areas Then the gold-rich soume rock of old Land supplied the basin with sediment,and the damp and warm climate p rovide abundant organisms,binally gold and organic matters were accumuled in the basin.By the time of late-Yanshanian,the basin tectonic activity had enhanced.Judging from the special formation and evolution conditions this gold.deposit of new tape has large prospective.The outcrop of mineralized rock extends 20km in Yazi gold mineralization area with the gold bed controled depth >700m.It is a new prospective area for deposit exploration.