van den Kerkhof, Alfons M., Sosa, Graciela M., Oberthür, Thomas, Melcher, Frank, Fusswinkel, Tobias, Kronz, Andreas, Simon, Klaus, Dunkl, István (2018) The hydrothermal Waterberg platinum deposit, Mookgophong (Naboomspruit), South Africa. Part II: Quartz chemistry, fluid inclusions and geochronology. Mineralogical Magazine, 82 (3) 751-778 doi:10.1180/mgm.2018.80
Reference Type | Journal (article/letter/editorial) | ||
---|---|---|---|
Title | The hydrothermal Waterberg platinum deposit, Mookgophong (Naboomspruit), South Africa. Part II: Quartz chemistry, fluid inclusions and geochronology | ||
Journal | Mineralogical Magazine | ||
Authors | van den Kerkhof, Alfons M. | Author | |
Sosa, Graciela M. | Author | ||
Oberthür, Thomas | Author | ||
Melcher, Frank | Author | ||
Fusswinkel, Tobias | Author | ||
Kronz, Andreas | Author | ||
Simon, Klaus | Author | ||
Dunkl, István | Author | ||
Year | 2018 (June) | Volume | 82 |
Page(s) | 751-778 | Issue | 3 |
Publisher | Mineralogical Society | ||
DOI | doi:10.1180/mgm.2018.80Search in ResearchGate | ||
Mindat Ref. ID | 245032 | Long-form Identifier | mindat:1:5:245032:6 |
GUID | 76e265c5-65fb-4a41-8ef5-fec13365a62c | ||
Full Reference | van den Kerkhof, Alfons M., Sosa, Graciela M., Oberthür, Thomas, Melcher, Frank, Fusswinkel, Tobias, Kronz, Andreas, Simon, Klaus, Dunkl, István (2018) The hydrothermal Waterberg platinum deposit, Mookgophong (Naboomspruit), South Africa. Part II: Quartz chemistry, fluid inclusions and geochronology. Mineralogical Magazine, 82 (3) 751-778 doi:10.1180/mgm.2018.80 | ||
Plain Text | van den Kerkhof, Alfons M., Sosa, Graciela M., Oberthür, Thomas, Melcher, Frank, Fusswinkel, Tobias, Kronz, Andreas, Simon, Klaus, Dunkl, István (2018) The hydrothermal Waterberg platinum deposit, Mookgophong (Naboomspruit), South Africa. Part II: Quartz chemistry, fluid inclusions and geochronology. Mineralogical Magazine, 82 (3) 751-778 doi:10.1180/mgm.2018.80 | ||
Abstract/Notes | AbstractThe historic Waterberg platinum deposit, ~15 km WNW of Mookgophong (formerly Naboomspruit), Limpopo Province, South Africa, is a rare fault-bound hydrothermal vein-type quartz-hematite-platinum-group mineralization. As a continuation of the geochemistry and ore mineralogy studies (Part I, Oberthür et al., 2018), this paper concentrates on the ore-bearing quartz and on the age constraints of ore formation. The state-of-the-art methods used include cathodoluminescence microscopy, electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of trace elements, stable isotope (δ18O) analysis and fluid-inclusion studies. U-Pb and (U-Th)/He radiometric age determination gave ages of 900–1075 Ma suggesting platinum-group element (PGE) mineralization as a result of upwelling fluids with connection to the Bushveld complex during Kibaran tectonic movements along the Thabazimbi–Murchison Lineament. Felsic fragments containing Qtz-1 were cemented by different quartz generations (Qtz-2 to Qtz-4) and enable the characterization of the changing physicochemical parameters during multistage mineralization and cooling. The PGE minerals are associated with the earliest hydrothermal stage represented by botryoidal radial-fibrous quartz aggregates (Qtz-2a) which formed on brecciated felsite. The other quartz types are essentially barren. Cathodoluminescence studies of quartz indicate very high Al, Fe and K concentrations as confirmed by EPMA and LA-ICP-MS, whereas Ti is always very low. The varying Al concentrations in the quartz mainly indicate pH fluctuations, the high Fe3+ points at high oxygen fugacity. Micro-inclusions of iron oxide are associated with Pt ore (Fe, Pt, Pd, Au, W, Sb, As), rutile, kaolinite and muscovite. The hydrothermal activity must have been characterized by low saline (<10 wt%) H2O–NaCl solutions. These fluids mixed with original high-saline NaCl ± CaCl2 ± CO2 brines in the brecciated felsite (Qtz-1). According to the quartz-hematite geothermometer the ore depositional temperatures were ~370–330°C (Qtz-2a), whereas the successive quartz veins formed during cooling towards ~295°C. The transport of PGE must have been facilitated by strongly oxidizing chloride complexes of relatively low salinity and moderate acidity. |
See Also
These are possibly similar items as determined by title/reference text matching only.