Platinum Group Element Segregation and Mineralization in a Noritic Ring Complex Formed from Proterozoic Siliceous High Magnesium Basalt Magmas in the Vestfold

• Main Authors: H. -michael Seitz, Reid, R. Keays
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1996
• Subjects: Basalts; Vestfold Hill; Vestfold; Vestfold Hills; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.528.4137; http://petrology.oxfordjournals.org/content/38/6/703.full.pdf

of country rock. It is suggested that the SHMB magma whichSiliceous High Magnesium Basalt (SHMB) magmas have been formed the Rubbly Norite lagged behind the rest of the SHMBimplied to play critical roles in the formation of platiniferous magma and spent some time in a residence chamber below thehorizons in layered intrusions such as the Bushveld Complex, South Noritic Ring Complex in which it underwent cooling, assimilation ofAfrica. However, their role in the formation of such complexes and country rock fragments and extensive crystallization of orthopyroxeneparticularly in the generation of the Cu–Ni–Platinum Group which accumulated along the floor of the temporary magma chamber.Element (PGE) sulphide mineralization has been deduced rather These factors caused S saturation of the SHMB magma and thethan proven. In this paper, we present an example of Cu–Ni–PGE generation of the Cu–Ni–PGE sulphides which accumulated alongsulphide mineralization which was unequivocally formed from with the orthopyroxene phenocrysts; the orthopyroxene- and sulphide-SHMB magmas. This example is provided by the Noritic Ring bearing magma was subsequently emplaced into the Noritic RingComplex of the northern Vestfold Hills of Antarctica. The Noritic Complex magma chamber. Economic concentrations of Cu–Ni–PGERing Complex is co-magmatic with the early Proterozoic High sulphides did not form in the Noritic Ring Complex because theMagnesium Tholeiite (HMT) dykes which were previously dem-SHMB magmas did not interact with an abundant source of S.onstrated to have formed from SHMB magmas. Chilled margins from the HMT have very similar PGE (average values: 16·0 p.p.b. Pd, 15·2 p.p.b. Pt, 0·98 p.p.b. Ru, 0·34 p.p.b. Ir) and