CUG: CUG Professor Sheds New Light on Magnetite Layer Formation

Prof. YAO Zhuosen (State Key Laboratory of Geological Processes and Mineral Resources and School of Earth Resources, CUG) and Prof. James E. Mungall (Department of Earth Sciences, Carleton University) co-authored “Magnetite layer formation in the Bushveld Complex of South Africa” which was published in Nature Communications. The abstract of the paper is as follows.

The great economic significance of layered mafic-ultramafic intrusions like the Bushveld Complex of South Africa results from the existence within them of some layers highly concentrated in valuable elements. Here we address the origins of the Main Magnetite Layer, a globally important resource of Fe-Ti-V-rich magnetite. Previous models of in situ fractional magnetite crystallization require frequent ad hoc adjustments to the boundary conditions. An alternative model incorporating compositional convection near the top of the pile and infiltration of the pile from beneath by migrating intercumulus melt fits observations without any adjustments. Lateral variations in Cr concentration formerly held as indisputable evidence for in situ crystallization can be accommodated better by models of reactive melt infiltration from below. The choice of models has pivotal ramifications for understanding of the fundamental processes by which crystals accumulate and layers form in layered intrusions.