陕西金堆城斑岩钼矿床成矿流体研究

陕西金堆城斑岩钼矿床是中国最大的钼矿床之一，按照脉体相互切割关系，成矿过程可分为两期十个阶段。矿区内流体包裹体研究表明：成矿流体以富CO2为特征，温度介于83℃～142℃之间，盐度介于27.5～42.5wt％NaCl两个区间内，具有典型的双配分模式特征。氢氧同位素特征研究表明成矿物质主要来源于岩浆流体。晚阶段有大量雨水混入热液流体中，导致流体的温度、盐度和δ18OH2O、δD值下降，引起了成矿流体中的钼金属沉淀，形成了金堆城超大型斑岩钼矿床。

STUDY ON THE ORE FORMING FLUID OFTHE JINDUICHENG PORPHYRY MOLYBDENUMDEPOSIT, SHANXI PROVINCE

The Jinduicheng Porphyry Molybdenum Deposit, Shanxi Province is one of the largest molybdenum deposits in China. Base on the observation of the cross-cutting sequence of veins, the whole ore-forming process can be divided into two periods and ten stages. The analysis of fluid inclusions in quartz indicates that the ore-forming hydrothermal system is rich in CO2. The average homogenization temperature ranges from 83 to 412℃. The salinty of metallogenetic fluid manifests bimodal distribution pattern with two ranges from 27.5 to 42.5 wt％ NaCl and from 0.61 to 17 wt％ NaC1 equiv. The values of oxygen and hydrogen isotope show that the major source of metallogantic element is magmatic fluid. At the last stage large amount of meteoric water was mixed into the hydrothermal system, leading to decrease of temperature, salinity, δ18OH2O andδD, and to precipitation of molybodnite which formed the main body of the super-large Jinduicheng molybdenum deposit.