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Tunnel support in South African mines
Published in Xia-Ting Feng, Rock Mechanics and Engineering, 2017
Two PGM-rich horizons are typically exploited – the Merensky economic horizon and UG2 chromitite seam. The PGMs recovered include platinum, palladium, rhodium, ruthenium and iridium, together with quantities of gold, nickel, copper and several other metals and compounds. The complex comprises a diversity of igneous rocks, with compositions varying from ultramafic to felsic. Typical rock types include norites, anorthosites, felspathic pyroxenite, pegmatoidal pyroxenite and chromitite.
Plutonic Rocks
Published in Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough, Earth Materials, 2019
Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough
The standard IUGS system for naming gabbroic rocks, shown in Figure 6.24, is based on the proportions of plagioclase, clinopyroxene (generally augite), and orthopyroxene in a rock. Gabbro contains mostly plagioclase and clinopyroxene, norite contains mostly plagioclase and orthopyroxene, and rocks in between are termed gabbronorite.
Petrogenesis of the Kalka, Ewarara and Gosse Pile layered intrusions, Musgrave Province, South Australia, and implications for magmatic sulfide prospectivity
Published in Australian Journal of Earth Sciences, 2023
W. D. Maier, B. Wade, Sarah-Jane Barnes, R. Dutch
Initial mineral chemistry studies on Kalka olivine and plagioclase were conducted by Goode (1970), using X-ray diffraction. Goode and Moore (1975) reported that Kalka orthopyroxene has Mg# 78–86 with Al2O3 1.6–5 wt%. Clinopyroxene has Mg# 72–84. Olivine in the Kalka OGZ has Fo70–85, in the lower Norite Zone olivine has up to Fo87, and in the AZ it has Fo75–60 (Goode 1970, 1976a). No data on Ni contents of olivine are available. Gray and Goode (1989) published abundant plagioclase compositional data for a profile across Kalka, showing a broad trend of upward decreasing An contents from ∼76 in the PZ (one sample having An67) to ∼60 at the top of the intrusion. Diversions from this trend include the OGZ (up to An83) and some samples with up to An76 in the AZ.
Isotopic investigations of the Nova-Bollinger Ni–Cu–Co deposit in the Fraser Zone, Albany-Fraser Orogen, Western Australia
Published in Australian Journal of Earth Sciences, 2022
V. Taranovic, Stephen J. Barnes, K. Baublys, K. Bathgate, M. L. Fiorentini
The Upper Intrusion (Figure 2) is a bowl-shaped, internally layered body extending about 2.4km N–S and about 1.2km E–W and up to 450m in thickness, divided into an upper Layered Series and a lower Basal Series. The Layered Series comprises feldspathic lherzolite layers of variable thickness from about 20cm to 100m interlayered at sharp phase appearance contacts with norite to gabbronorite rocks. Olivine within the lherzolites shows a distinct signal of sulfide-related olivine depletion (Barnes et al., 2022b). The lower Basal Series of the Upper Intrusion is a homogenous to vari-textured unit up to 100m thick of predominantly orthocumulate norite, olivine orthopyroxenite and feldspathic lherzolite. Taranovic et al. (2022) interpreted this unit to be a ‘basal reversal’ (Latypov, 2015) component of the Upper Intrusion.
Lapland Granulite Belt–Neoarchean subduction zone in the North-Eastern Baltic shield
Published in Applied Earth Science, 2021
N.E. Kozlov, E.V. Martynov, N.O. Sorokhtin
The Lovno intrusive complex is host to significant Ni–Cu sulphide mineralisation and is located in the central segment of the LGB close to the border of Russia and Finland (Figure 1). This intrusive complex is Paleoproterozoic and characterised by differentiated mafic-ultramafic intrusions comprising norite, gabbro and peridotite. The structure of the Lovno intrusion and composition of the rocks are much similar to the Monchegorsk intrusive complex that also hosts large Ni–Cu sulphide deposits (Gorbunov et al. 1985; Kozlov et al. 1988; Pozhilenko et al. 2002). Other occurrences of the Ni–Cu sulphide mineralisation are significantly smaller and hosted in discontinuous lenses of disseminated sulphides within discrete and small mafic and ultramafic intrusives scattered throughout the belt (Pozhilenko et al. 2002).