Reply to discussion by RN Scoon and AA Mitchell on the paper “The Bushveld complex, South Africa: formation of platinum-palladium, chrome and vanadium-rich layers via hydrodynamic sorting of a mobilized cumulate slurry in a large, relatively slowly cooling, subsiding magma chamber” by WD Maier, S-J Barnes, and DI Groves
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Scoon and Mitchell express certain reservations about our paper. First, the authors suggest that in modeling the Bushveld reefs, we only appeal to hydrodynamic sorting, which they consider unimportant. Second, they feel that we have failed to fully acknowledge and understand the Mitchell and Scoon (2007) model for the Merensky Reef in which they proposed formation of the Merensky pyroxenite and other platinum-group elements (PGE)-bearing horizons by injection of magma into semi-consolidated crystal piles. Third, the authors argue that we misrepresented their model for the origin of the platiniferous pipes.
Point 1: The model of Maier et al. (2013) was summarized in their Figure 23. The layering and the reefs are proposed to have formed through a reorganization of semi-consolidated cumulates that originally precipitated from multiple magma influxes by gravitational fractionation resulting in what may be termed proto-layers. The...
KeywordsChromite Picrite Bushveld Complex Sulfide Saturation Crystal Pilis
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- Maier WD, Barnes S-J, Groves DI (2013) The Bushveld complex, South Africa: formation of platinum-palladium, chrome and vanadium-rich layers via hydrodynamic sorting of a mobilized cumulate slurry in a large, relatively slowly cooling, subsiding magma chamber. Miner Deposita 48:1–56CrossRefGoogle Scholar