The Bushveld Igneous Complex (South Africa)

Dr. Ilka Kleinhanns and Prof. Ronny Schoenberg

The 2.05 Ga old Bushveld Complex covers an area of roughly 66’000 km² with a maximum vertical thickness of layered igneous rocks approaching ca 8 km. With these dimensions it represents the largest layered intrusion on Earth. The Bushveld Complex hosts a large proportion of the world resources of platinum and chromium within its so-called Rustenberg Layered Suite (RLS). The formation of numerous cyclic units within the RLS that carry the chromium and platinum layers is still highly debated, as is the overall tectonic setting active during the formation of the Bushveld Complex. This project aims to add new perspectives on both debates with combined petrological and geochemical investigations.

  • BSc Hilde Koch
  • MSc Maurice Brodbeck

Intra-plate volcanism at the Chaîne des Puys, Massif Central (France)

Dr. Ilka Kleinhanns, Dr. Carolina Rosca & Prof. Ronny Schoenberg

The ca. 3-4km wide and more than 35km long monogenetic Chaîne des Puys are among the youngest volcanic regions in Europe. Geophysical evidence shows mantle melting to be initiated by astenospheric upwelling. Erupted volcanic rocks comprise an almost complete petrologic range from undifferentiated alkali basalts and basanites to highly differentiated trachytes. Within this project, samples covering the complete petrologic range are fingerprinted with radiogenic Sr-Nd-Pb isotopes to judge contributing mantle and crustal materials. High degrees of differentiation presumably are caused by high-level magma chamber FC processes with relatively low degree of crustal assimilation. The setting of the Chaîne des Puys is thus offering the perfect scenario to study the behaviour of metal stable isotopes during fractional crystallisation and minor crustal assimilation (AFC).

  • BSc Luca Hiepe
  • MSc Kristina Eichholz & Mario Saussele