The Merensky Reef hosts one of the largest PGE resources globally. It has been exploited for nearly 100 years, yet its origin remains unresolved. In the present study, we characterised eight samples of the reef at four localities in the western Bushveld Complex using micro-X-ray fluorescence and field emission scanning electron microscopy. Our results indicate that the Merensky Reef formed through a range of diverse processes. Textures exhibited by chromite grains at the base of the reef are consistent with supercooling and in situ growth. The local thickening of the Merensky chromitite layers within troughs in the floor rocks is most readily explained by granular flow. Annealing and deformation textures in pyroxenes of the Merensky pegmatoid bear testament to recrystallisation and deformation. The footwall rocks to the reef contain disseminations of PGE rich sulphides as well as olivine grains with peritectic reaction rims along their upper margins suggesting reactive downward flow of silicate and sulphide melts. Olivine-hosted melt inclusions containing Cl-rich apatite, sodic plagioclase, and phlogopite suggest the presence of highly evolved, volatile-rich melts. Pervasive reverse zonation of cumulus plagioclase in the footwall of the reef indicates dissolution or partial melting of plagioclase, possibly triggered by flux of heat, acidic fluids, or hydrous melt. Together, these data suggest that the reef formed through a combination of magmatic, hydrodynamic and hydromagmatic processes.

梅伦斯基礁（Merensky Reef）是全球最大的PGE资源之一。它已经被开发了将近100年，但其起源至今仍未解决。在本研究中，我们使用微型X射线荧光和场发射扫描电子显微镜对西方Bushveld复杂地区四个地方的八个礁石样本进行了表征。我们的结果表明，梅伦斯基礁是通过一系列不同的过程形成的。礁底部的亚铬铁矿晶粒表现出的纹理与过冷和原位一致增长。粒岩流最容易解释地层岩石槽中Merensky铬铁矿层的局部增厚。Merensky钉状珠的辉石中的退火和变形织构证明了重结晶和变形。到达礁石的下盘壁岩石中散布着富含PGE的硫化物以及沿其上缘具有包晶反应边缘的橄榄石颗粒，表明硅酸盐和硫化物熔体的反应性向下流动。含有富含Cl的磷灰石，钠斜长石和金云母的橄榄石质熔体包裹体表明存在高度演化的，富含挥发性的熔体。礁底壁普遍存在斜长石斜带，表明斜长石溶解或部分融化，可能是由热，酸性流体或含水熔体引起的。一起，