Characteristics and sources of ore-forming fluids in the Atico IOCG deposit, Arequipa, Peru
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摘要:
秘鲁阿蒂科矿床是一个铁氧化物铜金矿床。含矿石英脉的流体包裹体均一温度为107~389℃,盐度为2.2%~23.18% NaCl。均一温度数据呈近似正态分布,但是,盐度数据总体不呈正态分布,且盐度较低,主要集中于0~10% NaCl和20%~30% NaCl之间。矿床δDV-SMOW和δ18OH2O的组成投影点靠近雨水线,反映该矿床成矿流体为大气降水来源。
Abstract:The Atico deposit is an IOCG deposit. Homogenization temperature of fluid inclusions in quartz varies from 107℃ to 389℃. The salinity range is 2.2%~23.18% NaCl. The homogenization temperatures are approximately in normal distribution, whereas the salinities are not in normal distribution and low, being mainly concentrated on 0~10%NaCl and 20%~30%NaCl. The fact that subpionts of δDV-SMOW and δ18OH2O of samples in the deposit suggests that the ore-forming fluids were mainly derived from atmospheric precipitation.
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Key words:
- IOCG deposit /
- ore-forming fluid characteristics /
- ore-forming fluid source /
- Atico /
- Peru
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图 1 秘鲁阿雷基帕省阿蒂科地区地质简图(据参考文献[11]修改)
Figure 1.
图 6 流体包裹体δDV-SMOW和δ18OH2O的组成关系图(底图据参考文献[12]修改)
Figure 6.
表 1 阿蒂科IOCG矿床含矿石英脉中流体包裹体显微测温数据
Table 1. Microthermometric measurement data for primary fluid inclusions in quartz from the Atico IOCG ore deposit
样品号 样品类型 包裹体类型 大小/μm 气液比/% 均一温度/℃ 盐度/%NaCl 最小值 最大值 所测包裹体个数 最小值 最大值 所测包裹体个数 D4120-2-1 早期成矿阶段含铜金石英脉 富含液相包裹体 5~30 10~20 142 319 31 4.03 19.84 31 D4120-2-2 5~23 15~20 176 321 28 5.41 8.14 28 D4120-2-3 5~22 5~15 146 321 28 4.18 23.05 26 D1108-2-1 晚期成矿阶段含金石英脉 5~17 10~30 187 337 27 4.8 10.49 26 D1108-2-2 3~11 15~30 160 389 21 5.33 23.18 17 D1108-2-3 3~18 15~30 170 271 32 6.45 17.48 28 D1109-2-1 3~14 15~30 140 234 32 7.86 23.18 25 D1109-2-2 3~14 10~20 130 228 34 7.73 23.18 29 D1109-2-3 3~14 10~20 154 261 35 2.2 23.18 33 D1111-2-1 3~11 10~20 122 198 24 23.05 23.18 18 D1111-2-2 3~11 10~20 110 219 24 5.56 23.18 21 D1111-2-3 4~15 10~20 107 169 26 20.52 23.18 21 D1111-4-2 4~28 10~20 110 271 27 4.69 23.11 21 表 2 石英中流体包裹体的δDV-SMOW和δ18OH2O数据
Table 2. δDV-SMOW and δ18OH2O data for fluid inclusions in quartz
样品编号 寄主矿物 δDV-SMOW/‰ δ18OH2O/‰ D4120-2 石英 -83 12.2 D1108-2 石英 -103 13.7 D1109-2 石英 -88 12.4 D1110-2 石英 -90 12.8 D1110-4 石英 -82 12.5 D1111-2 石英 -79 11.5 -
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