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Mineralium Deposita

, Volume 49, Issue 3, pp 405–407 | Cite as

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

  • Wolfgang D. MaierEmail author
  • Sarah-Jane Barnes
  • David I. Groves
Reply
  • 361 Downloads

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.

Our response to these points is the following:
  • 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...

Keywords

Chromite Picrite Bushveld Complex Sulfide Saturation Crystal Pilis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Barnes S-J, Maier WD, Curl E (2010) Composition of the marginal rocks and sills of the Rustenburg Layered suite, Bushveld complex, South Africa: implications for the formation of the PGE deposits. Econ Geol 105:1491–1511CrossRefGoogle Scholar
  2. Borisov A, Palme H (2000) Solubilities of noble metals in Fe containing silicate melt as derived from experiments in Fe-free systems. Amer Mineral 85:1665–1673Google Scholar
  3. Campbell IH, Naldrett AJ, Barnes SJ (1983) A model for the origin of the platinum-rich sulfide horizons in the Bushveld and Stillwater complexes. J Petrol 24:133–165CrossRefGoogle Scholar
  4. Cawthorn RG, Davies G (1983) Experimental data at 3 Kbars pressure on parental magma to the Bushveld complex. Contrib Mineral Petrol 83:128–135CrossRefGoogle Scholar
  5. Davies G, Cawthorn RG, Barton JM, Morton M (1980) Parental magma to the Bushveld complex. Nature 287:33–35CrossRefGoogle Scholar
  6. 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
  7. Mitchell AA, Scoon RN (2007) The Merensky reef at Winnaarshoek, Eastern Bushveld complex: a primary magmatic hypothesis based on a wide reef facies. Econ Geol 102:971–1009CrossRefGoogle Scholar
  8. Scoon RN, Mitchell AA (2004) The platiniferous dunite pipes in the eastern limb of the Bushveld complex: review and comparison with unmineralized discordant ultramafic bodies. S Afr J Geol 107:505–520CrossRefGoogle Scholar
  9. Scoon RN, Mitchell AA (2009) A multi-stage orthomagmatic and partial melting hypothesis for the Driekop platiniferous dunite pipe, eastern limb of the Bushveld complex, South Africa. S Afr J Geol 112:163–186CrossRefGoogle Scholar
  10. Scoon RN, Mitchell AA (2011) The principal geological features of the Mooihoek platiniferous dunite pipe, eastern limb of the Bushveld complex, South Africa, and similarities with replaced Merensky reef as the Amandelbult mine. S Afr J Geol 114:15–40CrossRefGoogle Scholar
  11. Sharpe MR (1981) The chronology of magma influxes to the eastern compartment of the Bushveld complex, as exemplified by its marginal border group. J Geol Soc Lond 138:307–326CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Wolfgang D. Maier
    • 1
    Email author
  • Sarah-Jane Barnes
    • 2
  • David I. Groves
    • 3
  1. 1.School of Earth and Ocean SciencesCardiff UniversityCardiffUK
  2. 2.Sciences de la TerreUniversité du Québec à ChicoutimiChicoutimiCanada
  3. 3.Centre for Exploration TargetingUniversity of Western AustraliaCrawleyAustralia

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