摘要
乳山金矿床位于牟平－乳山金矿带中部的昆嵛山花岗岩体内，是胶东近年来探明的一个重要石英脉型金矿床。流体包裹体地球化学研究表明，该矿床流体包裹体的气相成分以Ｈ２Ｏ、ＣＯ２为主；液相中的阳离子贫Ｎａ＋、Ｋ＋，富Ｃａ２＋、Ｍｇ２＋，而且Ｎａ＋／Ｋ＋＞１、（Ｃａ２＋＋Ｍｇ２＋）＞（Ｎａ＋＋Ｋ＋）；成矿流体的盐度（ＮａＣｌ当量）约为５％－９％，主要成矿期的温度为２２０－２８０℃，矿后期则为１３０－２００℃。昆嵛山岩体和乳山金矿床的同位素年龄分别为１３４．３－１２４．５Ｍａ和８０±Ｍａ，矿岩时差大（４５－５５Ｍａ），氢、氧同位素研究证实，金矿床成矿热液中的水主要为大气降水，在不同的ｗ／Ｒ值条件下。
The Rushan gold deposit, one of the important quartz-vein type gold deposits,is located in the Kunyushan granitic pluton. It lies in the central part of the Muping-Rushan gold metallogenic belt. A detailed study on fluid inclusion geochemistry indicates that the gaseous phase of the fluid inclusions is dominated by H_2O and CO_2, while the liquid phase is poor in Na+, K+, and rich in Ca(2+), Mg￣(2+), and characterized by Na￣+/K￣+>1 and Ca￣(2+)+Mg￣(2+)>Na￣++K￣+. The salinity (wt.% NaCl equiv.) of the mineralizing liquid ranges from 5 to 9, the main mineralization stage has a temperature of about 220-280℃, and the late stage temperature is at about 130-200℃. The isotopic ages of the Kunyushan pluton and Rushan gold deposit are 134.3-124.5Ma and 80±Ma, respectively, indicating a great time interval between the crystallization of the pluton and the formation of the deposit (45-55Ma). The hydrogen and oxygen isotopic data show that the mineralizing solution is mainly derived from meteoric water. A genetic model is proposed to explain the metallogenetic mechanism of the gold deposit.
出处
《地球化学》
CAS
CSCD
北大核心
1995年第C00期141-149,共9页
Geochimica
基金
国家自然科学青年基金
关键词
山东
乳山金矿床
流体包裹体
氢氧同位素
成分特征
同位素组成
quartz-vein type gold deposit
fluid inclusion
hydrogen and oxygen isotopes
metallogenetic mechamism, Shandong Province
