辽宁北地金矿地球化学特征  

Geochemical characters on Beidi gold deposit in Liaoning

作　　者：朴寿成[1] 于泽新 李清泉[1] 张博文[1] 师磊[1] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]朝阳金达集团实业有限公司,辽宁朝阳122000

出　　处：《世界地质》2008年第2期172-177,共6页World Geology

摘　　要：北地金矿产于燕山期石英二长岩与太古宙建平群小塔子沟组变质杂岩的内接触带,主成矿阶段的温度为240～360℃,盐度(NaCl)为1%～6%,成矿压力为105.5×106～156×106Pa,矿化深度为3.52～6.24km,属中温中深成脉状热液矿床。从矿石的石英及其包裹体获得的δD分别为-88.44×10-3和-88.96×10-3,δ18O分别为5.08×10-3和5.11×10-3,成矿流体主要来源于岩浆水。燕山期石英二长岩形成过程和区内广泛分布的太古宙变质杂岩都可能提供了部分成矿物质。矿石的石英流体包裹体均一温度和盐度都有双峰现象,均一温度峰值分别为160℃～220℃和280℃～300℃,盐度(NaCl)的峰值分别为3%～4%和7%～8%,矿质的沉淀、富集可能与流体的不混溶有关。The Beidi gold deposit occurs at the inner contact zone between the Mesozoic quartz monzonite and the metamorphic rocks in the Archean Xiaotazigou Formation of Jianping Group. With ore-forming temperature of the major mineralizing stage during 240 -360 ℃, salinity of 1% -6% , ore-forming pressure of 105.5×10^6 -156 × 10^6pa and ore-forming depth of 3.52 - 6.24 km, the gold deposit is thought to be mesothermal gold lode depos- it. δD of quartz and inclusion in the ores are -88.44 × 10^-3and -88.96 × 10^-3, respectively, while δ^18O are 5.08 × 10^-3and 5.11 × 10^-3, which indicate that the ore fluid mainly came from magmatic water. Both the formation processes of the Mesozoic quartz monzonite and the widespread Archean metamorphic rocks could provide some ore-forming materials. Both the ore-forming temperature and salinity of the fluid inclusions in ores show two-peak distributios in their frequency diagram. The two temperature peaks range from 160℃ to 220℃ and 280℃ to 300℃, and the two salinity （NaCl） peaks of the fluids are 3% - 4% and 7% - 8% , respectively. The precipitation and enrichment of the ore-forming materials are possibly related to the unmixing of the ore-fluid.

关 键 词：北地金矿 流体包裹体 微量元素 氢、氧同位素 地球化学 

分 类 号：P618.51[天文地球—矿床学] P595[天文地球—地质学]