Fe-Cu-Zn同位素在矿床学和找矿勘查中的应用

金属稳定同位素已经广泛应用于矿床学研究以及找矿勘查。金属来源及其成矿过程是金属矿床研究以及找矿勘查中重点关注的基本核心问题。金属稳定同位素这项新技术进一步提高了我们对地壳中金属来源、迁移和富集的认识。这项新技术的优点是我们可以直接从矿石矿物本身获取信息。在本文中,我们重点关注矿石、水、岩石、土壤、植物等测量出的Fe-Cu-Zn同位素分馏,聚焦于Fe-Cu-Zn同位素从最深部岩浆系统开始一直向上延伸到浅部表生系统的过程中Fe-Cu-Zn同位素如何应用于矿床学研究以及找矿勘查,试图展示这些相对较新的技术可以提供的潜在应用范围。经过系统研究和总结,我们认为金属稳定同位素数据可以从三方面加以利用。首先,地表的植物、水、风化的岩石以及土壤中产生的较大的同位素分馏可以作为地下矿产勘查的指示标志;第二,矿区范围内金属稳定同位素往往具有系统的空间变化规律,可以指示成矿热液空间演化模式和矿体延伸方向;第三,金属元素作为成矿元素,其同位素可以直接有效地约束矿石的形成过程、成因以及源区特征。

The application of Fe-Cu-Zn isotopes in ore deposit research and prospecting exploration

Stable metal isotopes have been widely applied to ore deposit research and prospecting exploration. One of the fundamental questions associated with ore deposits is to understand where metals originated and how these systems became endowed with the metal budget they possess. Relatively new techniques of stable metal and metal isotope have begun to further advance our understanding of metal source, migration and concentration in the crust. The advantage of using these metal isotope systems is that we can derive information directly from the ore minerals themselves. In this paper, we pay close attention to Fe-Cu-Zn isotopic fractionation measured in ores, waters, rocks, soils and plants, then focus on how the Fe-Cu-Zn isotopes can aid in ore deposit research and prospecting exploration by starting with the deepest magmatic systems and working upwards to the supergene systems, in an attempt to display the range of potential applications these relatively new techniques can provide. Through systematic research and summary, we suggest that three aspects of the stable metal isotopic data can be used. Firstly, the large fractionation found to occur at the surface of the earth permits the use of waters, weathered rocks, soils, and plants as vectors to ore in the subsurface. Secondly, the stable metal isotopes usually exhibit systematic spatial variations within orefield, which can indicate the spatial evolution pattern of ore-forming hydrothermal fluids and the extending direction of orebody. Thirdly, as the ore-forming elements, the stable metal isotopes can directly constrain the ore formation, genesis and source characteristics.