文档介绍：
老王寨金矿 Pb、Sr 和 Nd 同位素组成特征
及意义#
邓碧平,刘显凡**
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(成都理工大学地球科学学院,成都市,610059)
摘要:通过对老王寨金矿床岩矿石锶-钕-铅同位素组成的研究表明,锶-钕-铅同位素组成总
体上相对稳定集中,具有共同的来源,岩矿石高 87Sr/86Sr、低 143Nd/144Nd、高 206Pb/204Pb
特征可能反映了成矿流体可能源自交代富集地幔,主要是板块俯冲海洋沉积物被带入地幔楔
与地幔混合的结果。综合研究表明,老王寨金矿床成矿流体主要源于深部地幔,在参与交代
蚀变过程中,其性质由熔浆向热液过渡,同时引发壳幔物质混染而有利于成矿作用的进行。
关键词:铅同位素;锶同位素;钕同位素;深源成矿流体;老王寨金矿床
中图分类号:
Pb-Sr-Nd positions and their Geological
implications of Laowangzhai gold deposits
Deng Biping, Liu Xianfan
(College of Earth Science,Chengdu University,Chengdu,610059)
Abstract: The study of Sr-Nd-Pb isotopic data for rocks and ores from the Laowangzhai gold
deposit shows that Sr-Nd-Pb positions are generally stable and have the same
origination; high 87Sr/86Sr ratios, low 143Nd/144Nd ratios and high 206Pb/204Pb ratios of rocks
and ores may be the reflection of ore-forming fluids deriving from the metasomatic enriched
mantle and are mainly the result of mantle mixing with ocean sediments which are carried into
mantle wedges through plate subduction. From what has been discussed above, the ore-forming
fluids of the Laowangzhai gold deposit mainly derive from deep mantle, and their properties are
transformed from magma fluids to hydrothermal fluids in the course of metasomatism and
alteration, which leads to initiate crust-mantle mixing simultaneously to be in favor of
mineralization.
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