加拿大阿尔伯塔大学Xinyue Xu团队最新的研究提出了磁铁矿-磷灰石矿石记录了熔融盐类的广泛参与这一新成果。2024年3月1日，国际知名学术期刊《地质学》发表了这一成果。

在这里，研究人员展示了来自世界各地20个磁铁矿—磷灰石矿床的证据，表明它们普遍涉及熔融盐。所研究的矿床分布在全球，不同的构造背景下，地质年代从前寒武纪到第四纪。在每一种情况下，矿石阶段矿物中的贫水多晶熔融包裹体主要由硫酸盐、氯化物和碳酸盐组成，以及不同比例的钙硅酸盐、磷酸盐和铁钛氧化物，这些成分在285°C至1100°C之间重新熔融。

这些流体与大多数地质环境中的预期流体非常不同，但它们在磁铁矿—磷灰石岩石中的普遍存在表明，熔融盐广泛存在，对这些矿床的形成至关重要。

据介绍，磁铁矿—磷灰石矿床的起源是有争议的，争论的焦点在于这些这些岩石是由什么样的流体类型形成的。

附：英文原文

Title: Magnetite-apatite ores record widespread involvement of molten salts

Author: Xinyue Xu, Wyatt M. Bain, Fernando Tornos, John M. Hanchar, Hector M. Lamadrid, Bernd Lehmann, Xiaochun Xu, Jeffrey A. Steadman, Ralph S. Bottrill, Majid Soleymani, Abdorrahman Rajabi, Peng Li, Xuehai Tan, Shihong Xu, Andrew J. Locock, Matthew Steele-MacInnis

Issue&Volume: 2024-03-01

Abstract: The origins of magnetite-apatite deposits are controversial, and the crux of the debate is what types of fluids form these rocks. We present evidence from 20 magnetite-apatite deposits worldwide showing ubiquitous involvement of molten salts. The studied deposits are distributed globally, from various tectonic settings, and from Precambrian to Quaternary in age. In every case, water-poor polycrystalline melt inclusions in ore-stage minerals are dominated by sulfate, chloride, and carbonate components plus variable proportions of calc-silicates, phosphates, and iron ± titanium oxides that re-melt between 285 °C and 1100 °C. These fluids are very different from what is generally expected in most geologic settings, but their ubiquitous presence in magnetite-apatite rocks indicates that molten salts are widespread and essential to the formation of these deposits.

DOI: 10.1130/G51887.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G51887.1/635786/Magnetite-apatite-ores-record-widespread