福建政和马仑头金矿成矿物理化学条件及成因分析

Analysis on the Metallogenic Physicochemical Condition and the Genesis of Maluntou Gold Deposit in Zhenghe County,Fujian Province

通过流体包裹体、H-O同位素、S同位素和Rb-Sr同位素研究,分析政和马仑头金矿床形成物理化学条件和成因。流体包裹体研究显示,流体演化成矿经历了187~244℃和149~168℃两个主要阶段。其中与成矿密切相关的温度峰值是187~244℃对应第二阶段硫化物阶段。H-O同位素显示,矿床成矿流体在演化过程中,随着成矿作用的进行,有越来越多的大气降水加入。矿石S同位素研究显示,硫可能来自深源岩浆,成矿物质与区内早白垩世的火山活动有关。Rb-Sr同位素研究结果,矿床成矿年龄为(101±1)Ma,其形成与区内火山活动密切相关。综合研究成果,初步判断马仑头矿床为火山-次火山热液型金矿床。

This paper makes a detailed analysis of the metallogenic physicochemical condition and the genesis of Maluntou gold deposit according to the study of the fluid inclusions and the HO,S and Rb-Sr isotopes.The study of the fluid inclusions suggests that the evolution of the ore-forming fluids can be divided into two stages,of which the temperature peaks are 187-244℃ and 149-168℃respectively.It should be pointed out that the 187-244℃stage,corresponding to the sulfide stage,is more closely related to mineralization.The study of the H-O isotopes shows that there will be more and more atmospheric precipitation added into the ore-forming fluids following the mineralization.The study of the S isotopes indicates that the S isotopes may be derived from the deep magma and the ore-forming materials are associated with Early Cretaceous volcanism.The study of the Rb-Sr isotopes states that the metallogenic age is(101±1)Ma.In conclusion,Maluntou gold deposit is a volcanic-subvolcanic hypothermal one.