The petrogenetic link between Kiruna-type ore deposits and their host silicic igneous rocks: the Vergenoeg Fe-F-REE deposit in the Bushveld large igneous province (South Africa).

硅质大火成岩省（slip）常含有重要的铁（±Cu、±REE、±U、±P、±F）矿床。此类矿床的形成，特别是岩浆与热液/交代作用的相对作用，几十年来一直存在争议，矿床多被划分为氧化铁-铜-金（IOCG）型或基鲁纳型矿床。在这项研究中，我们建议重建世界上最大的F矿床之一，南非的vergeneg F- fe - ree矿床的岩石成因演化。vergeneg矿床位于世界上最大的滑梯之一，火山Rooiberg群，它是Bushveld大火成岩省的一部分，以流纹岩为主。关于vergeneg的金属富集，人们提出了几种相互矛盾的岩石成因模式，可分为岩浆成因和热液成因两大类。我们将研究长英质岩石类型（Rooiberg流纹岩和Bushveld花岗岩）的石英、长石、费长石、磁铁矿和磷灰石中的熔体包裹体和矿体，以确定vergeneg的成矿来源，即不混溶的富铁熔体与富铁- f - ree花岗熔体（通过富铁- f - ree流体的排出形成矿石）。这些研究将由矿石和寄主岩石的铁和氧稳定同位素分析来补充。主要矿相磁铁矿、铁矾石、萤石和磷灰石的主微量元素分析将有助于了解不混相熔体之间的元素分配（尤其是稀土元素）和/或它们在热液溶解、富集和再沉淀过程中的行为。研究结果将提供重要的数据，以阐明岩浆和/或热液作用对滑脱带中Fe（±REE，±F）矿床形成的作用，并有助于更好地理解这些Fe-F-REE与iocg型或kiruna型矿床之间的岩石成因联系。

Silicic large igneous provinces (SLIPs) frequently contain important Fe (±Cu, ±REE, ±U, ±P, ±F) ore deposits. The formation of such ore deposits, especially the relative roles of magmatic versus hydrothermal/metasomatic processes, is under debate since decades and the deposits are mostly classified as iron oxide-copper-gold (IOCG)-type or Kiruna-type deposits. In this study, we propose to reconstruct the petrogenetic evolution of the Vergenoeg F-Fe-REE deposit in South Africa, one of the largest F deposits of the world. The Vergenoeg deposit is situated within one of the largest SLIPs of the world, the volcanic Rooiberg Group, which is part of the Bushveld large igneous province and is dominated by rhyolites. Several contradicting petrogenetic models have been proposed for metal enrichment in Vergenoeg, which can be grouped into magmatic versus hydrothermal approaches. We will study melt inclusions trapped in quartz, feldspars, fayalite, magnetite, and apatite of the hosting felsic rock types (Rooiberg rhyolites and Bushveld granitoids) and the ore body in order to identify the source for ore formation at Vergenoeg, i.e., immiscible Fe-rich melt vs. Fe-F-REE rich granitic melt (hydrothermal formation of the ore by expulsion of Fe-F-REE-rich fluids). These investigations will be complemented by Fe and O stable isotope analyses of the ore and the host rocks. Major and trace element analysis of the main ore phases magnetite, fayalite, fluorite and apatite will provide insight into the partitioning of elements (especially the REE) between immiscible melts and/or their behavior during hydrothermal solution, enrichment and re-precipitation processes. The results of the study will provide important data allowing to elucidate the role of magmatic and/or hydrothermal processes on the formation of Fe (±REE, ±F) ore deposits in SLIPs and will contribute to a better understanding of the petrogenetic link between these Fe-F-REE and either IOCG-type or Kiruna-type ore deposits.