万宝源斑岩型钼矿流体包裹体及成矿物质来源研究

Fluid Inclusions and Origin of the Wanbaoyuan Porphyry Mo Deposit

万宝源斑岩型钼矿位于辽东裂谷内,产于石柱子花岗闪长岩体及其后侵入的石英斑岩内。矿化类型可以分为浸染状、细脉充填状和石英脉状三种。为了解决该钼矿的成矿流体来源及矿床形成机制问题,我们从流体包裹体、REE、S、D-O同位素入手进行了研究。石英中的流体包裹体测试数据揭示:钼矿化可以分为三个阶段,高温阶段、中温阶段和低温阶段,以中温阶段为主。REE分析表明,成矿物质起源于花岗闪长岩体,后经分离结晶作用,最终与花岗闪长岩体表现出不同的REE配分模式;S同位素分析显示,S来源于岩体与地层,是一种混合硫;D-O同位素研究则说明,成矿流体是以岩浆水为主,后期有天水加入的混合流体。最后建立石柱子成矿系统,对石柱子花岗闪长岩内外接触带上的矿床成因进行了探讨。

Wanbanyuan porphyry Mo deposit is located in Liaodong Rift and hosted by late Yanshanian Shizhuzi granodiorite body and later quartz porphyry. Mineralization types , according to host rocks and structure are divided into disseminated, veinlet - filled and quartz - vein ore. In order to solve the questions of ore- forming fluid source and ore -forming mechanism, fluid inclusions, REE, S and D- O stable isotope are studied. Vapor- liquid fluid inclusions data from quartz indicate that Mo mineralization experienced three stages ： high temperature, middle temperature and low temperature, and mid - temperature stage is the main stage. REE data shows Mo derived from granodiorite and finally resulted in different distribution patterns. S isotopic data suggest both origin of both diorite and wall rocks, a mixed source. D - O data shows the main ore fluid is mainly magmatic fluids, mixed with meteoric water. In the end, ore - froming mechanism around the granodiorite is discussed.