含矿流体以温度、压力、盐度和侵位深度降低的连续演化特点
刘显凡
深部地质过程的流体包裹体与稀有气体同位素特征-以云南老王寨金矿床为例[EB/OL]
北京:中国科技论文在线
主要从事矿物学、岩石学、矿床地球化学研究 【收录情况】 中国科技论文在线: 邓碧平
这一演化过程反映,来自深部的地幔流体与地壳流体和物质相互作用
) Abstract: The study of fluid inclusions from the Laowangzhai gold deposit shows that: types of fluid inclusion in auriferous quartz veins are mainly NaCl-H2O inclusions and CO2-H2O inclusions, homogeneous temperature of fluid inclusions are concentrated in 300
0~350
0℃, salinity are between 9
209%NaCleqv and 9
856%NaCleqv, metallogenic pressure varies from 827×105Pa to 1084×105Pa and emplacement depth is about 3
18~4
17km in the frontal metallogenic stage; homogeneous temperature are concentrated in 195
0~225
0℃, salinity are between 4
495%NaCleqv and 4
650%NaCleqv, metallogenic pressure varies from 711×105Pa to 736×105Pa and emplacement depth is about 2
73~2
83km in the metallogenic stage; homogeneous temperature are concentrated in 106
8~171
1℃, salinity are between 2
737%NaCleqvNaCleqv and 4
650%NaCleqv, metallogenic pressure varies from 410×105Pa to 460×105Pa and emplacement depth is about 1
58~1
77 km in the post metallogenic stage
Noble gas isotope measurement displays that: 3He/4He ratios of ore-forming fluids are averagely 0
4614 Ra, which is higher than the crustal eigenvalue and lower than the mantle eigenvalue; 40Ar/36Ar ratios and 38Ar/36Ar ratios are averagely 341
8 and 0
20675 respectively, which are higher than air,s, and lower than MORB,s or OIB,s; 129~136Xe/130Xe ratios all show surplus characteristics compared with air,s
Combined with the study of noble gas isotope, the characteristics of fluid inclusions from the gold deposit reveals that: the deep CO2 -bearing hydrothermal solution with high temperature and high pressure carries metallic elements from deep to shallow; companying with the temperature and pressure decreasing and CO2 escaping, the solution is supersaturated and gold and metal sulfides such as pyrite are precipitated off to form the deposit; from the frontal metallogenic state(Ⅰ)→the metallogenic state(Ⅱ)→the post metallogenic state(Ⅲ), the mineral-laden fluid presents the continuous evolution characteristics of temperature, pressure and salinity decreasing and emplacement rising; which indicates that the interaction between the deep fluids derived from mantle and the crustal materials results in the mixture of crust-mantle materials to be favourable for mineralization
Keywords: fluid inclusions
) 摘要: 老王寨金矿床流体包裹体研究表明:含金石英脉中流体包裹体类型主要为NaCl-H2O 型和CO2-H2O型
成矿阶段(Ⅱ)均一温度主要在195
0~225
0℃
主要从事矿物学、岩石学、矿床地球化学研究 通信联系人: 刘显凡(1957-)
稀有气体同位素测定显示:成矿流体3He/4He比值平均为0
4614 Ra
成矿压力变化于827~1084×105Pa/km
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