辽南分水金矿床铅同位素特征及矿床成因

Pb isotope characteristics and genesis of Fenshui gold deposit of the southern part of Liaoning Province

分水金矿位于石棚峪超单元北西外接触带上,二者有着密切的空间分布关系。铅同位素特征显示,金矿成矿物质来源于(186±13)Ma及2 800 Ma±的两个源区。燕山早期阶段,石棚峪超单元黑云母碱长花岗岩在中深成侵入活动[(186±13)Ma]中,所分异的岩浆期后热液在运移就位过程中萃取了部分围岩(2 800 Ma±)的成矿物质,稍晚于(186±13)Ma形成金、铅矿床。

Fenshui gold deposit occurs in northeast of Dashiqiao Country and it lies in NW external contact belt of Shipengyu super-unit, the spatial distribution of both have close relationship. It is post-magmatic mesothermal deposit. The characteristics of lead isotope show that ore-forming material of Fenshui gold deposit originated from two sources of 186±13Ma and 2 800Ma±. In early Yanshan stage, post-magmatic hydrothermal solution from middle-plutonic intrusive activities （186±13Ma） of Shipengyu ultra-unit boitile alkali-feldspar granite drew some ore-forming material from country rocks （2 800Ma±） ,the differentiation of the magmatic hydrothermal in the process of migration,later on （186±13） Ma formed gold, lead ore deposits.