Seltenerdelement-Mineralisationen im Palabora Karbonatit-Komplex
Zusammenfassung der Projektergebnisse
Samples from a 2 km deep drill core profile of intercalated carbonatite, phoscorite and pyroxenite (Palabora complex) were investigated for their REE mineralization and mineralogical and mineral chemical variation. Samples from the Kaiserstuhl carbonatite were used for comparison. The results of these studies revealed that (i) a multi-stage evolution of the REE mineralization resulted in an accumulation of specific REE minerals. (ii) Late magmatic REE mineralization caused the most important REE enrichment, while postmagmatic remobilization caused the most efficient REE redistribution and accumulation. (iii) Contamination by silicate wall rocks during the magmatic stage causes an early consumption of REE by non-REE minerals (apatite), which prevents a late magmatic enrichment to form discrete REE minerals. (iv) REE mineralization in carbonatites and associated phoscorites is similar. (v) Phoscorites and carbonatites form from a common parental magma by liquid immiscibility. This separation enables carbonatites to start a jet-like ascent through the crust.
Projektbezogene Publikationen (Auswahl)
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Multi-stage formation of REE minerals in the Palabora Carbonatite Complex, South Africa. American Mineralogist, 102(6), 1218-1233.
Giebel, R. Johannes; Gauert, Christoph D.K.; Marks, Michael A.W.; Costin, Gelu & Markl, Gregor
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A model for the formation of carbonatite-phoscorite assemblages based on the compositional variations of mica and apatite from the Palabora Carbonatite Complex, South Africa. Lithos, 324-325, 89-104.
Giebel, R. Johannes; Marks, Michael A.W.; Gauert, Christoph D.K. & Markl, Gregor
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Evidence for Magma–Wall Rock Interaction in Carbonatites from the Kaiserstuhl Volcanic Complex (Southwest Germany). Journal of Petrology, 60(6), 1163-1194.
Giebel, R. J.; Parsapoor, A.; Walter, B. F.; Braunger, S.; Marks, M. A. W.; Wenzel, T. & Markl, G.
