The hydrothermal Waterberg platinum deposit, Mookgophong (Naboomspruit), South Africa. Part II: Quartz chemistry, fluid inclusions and geochronology

2018 ◽  
Vol 82 (3) ◽  
pp. 751-778 ◽  
Author(s):  
Alfons M. van den Kerkhof ◽  
Graciela M. Sosa ◽  
Thomas Oberthür ◽  
Frank Melcher ◽  
Tobias Fusswinkel ◽  
...  
Keyword(s):  
South Africa ◽  
Inductively Coupled Plasma ◽  
Age Determination ◽  
Hydrothermal Activity ◽  
Limpopo Province ◽  
Chloride Complexes ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Platinum Group

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.

scholarly journals Algae colonisation of brick pavement at the University of Venda: A potential slippery hazard

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
Thabelo R. Munyai ◽  
Thandi Sonqishe ◽  
Jabulani R. Gumbo
Keyword(s):  
Green Algae ◽  
Inductively Coupled Plasma ◽  
Limpopo Province ◽  
Inductively Coupled ◽  
High Solar Radiation ◽  
Icp Ms ◽  
Metal Contents ◽  
Plasma Mass Spectrometry ◽  
Cyanobacteria And Algae ◽  
The University

A brick pavement, tramped by humans, is exposed to atmospheric elements, thus allowing cyanobacteria and algae to colonise. In this article, we report on the factors that contribute to the slipperiness of a brick pavement at the University of Venda in the Limpopo province of the South Africa. Samples were collected from brick surfaces either colonised by green algae (treated) or not (control). The samples were acid-digested and analysed for metals by Inductively Coupled Plasma Mass Spectrometry (ICP MS) in parts per billion (ppb). The treated bricks, with green algae, had average high metal contents (ppb): Al 9456.02, Ti 731.23, V 46.44, Cr 78.85, Mn 862.93, Fe 16295.18, Co 23.57, Ni 59.36, Cu 66.31, Zn 160.57, As 7.92, Se 10.45, Mo 6.74, Cd 5.19, Sn 4.65, Sb 2.31 and Pb 19.51. In contrast, control bricks had a low average of metal content (ppb) as follows: Al 2.99, Ti 0.28, V 4.04, Cr 1.42, Mn 4.29, Fe 20.89, Co 0.36, Ni 2.74, Cu 5.64, Zn 4.21, As 0.56, Se <3.00, Mo 0.88, Cd 0.01, Sn 1.05, Sb 0.04 and Pb 0.04. Other factors that promote algae colonisation include high solar radiation, neutral pH, nutrients, low electrical conductivity and total dissolved solids. The algae colonisation of brick pavement results in an unaesthetic sighting and a slippery surface that is hazardous to humans.

scholarly journals U-Pb zircon age of the youngest magmatic activity in the High Tatra granites (Central Western Carpathians)

2013 ◽  
Vol 40 (2) ◽  
pp. 134-144 ◽  
Author(s):  
Jolanta Burda ◽  
Aleksandra Gawęda ◽  
Urs Klötzli
Keyword(s):  
Inductively Coupled Plasma ◽  
Age Groups ◽  
Hydrothermal Activity ◽  
Magmatic Activity ◽  
Zircon Age ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Central Western Carpathians ◽  
High Tatra Mountains

Abstract Detailed cathodoluminescence (CL) imaging of zircon crystals, coupled with Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS) U-Pb zircon dating was used to develop new insights into the evolution of granitoids from the High Tatra Mountains. The zircon U-Pb results show two distinct age groups (350±5 Ma and 337±6 Ma) recorded from cores and rims domains, respectively. Obtained results point that the last magmatic activity in the Tatra granitoid intrusion occurred at ca. 330 Ma. The previously suggested age of 314 Ma reflects rather the hydrothermal activity and Pb-loss, coupled with post-magmatic shearing.

U–Pb age determination of schorlomite garnet by laser ablation inductively coupled plasma mass spectrometry

2018 ◽  
Vol 33 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Yue-Heng Yang ◽  
Fu-Yuan Wu ◽  
Jin-Hui Yang ◽  
Roger H. Mitchell ◽  
Zi-Fu Zhao ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Inductively Coupled Plasma ◽  
Age Determination ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Alkaline Complexes

We report the first U–Pb geochronological investigation of schorlomite garnet from carbonatite and alkaline complexes and demonstrate its applicability for U–Pb age determination using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to its relatively high U and Th abundances and negligible common Pb content.

scholarly journals Rare earth elements in oyster shells: provenance discrimination and potential vital effects

2020 ◽  
Vol 17 (8) ◽  
pp. 2205-2217
Author(s):  
Vincent Mouchi ◽  
Camille Godbillot ◽  
Vianney Forest ◽  
Alexey Ulianov ◽  
Franck Lartaud ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Hydrothermal Activity ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Significant Difference ◽  
Plasma Mass Spectrometry ◽  
Vital Effects ◽  
Bivalve Shells

Abstract. Rare earth elements (REEs) and yttrium in seawater originate from atmospheric fallout, continental weathering, and transport from rivers, as well as hydrothermal activity. Previous studies have reported the use of REE and Y measurements in biogenic carbonates as a means to reconstruct these surface processes in ancient times. As coastal seawater REE and Y concentrations partially reflect those of nearby rivers, it may be possible to obtain a regional fingerprint of these concentrations from bivalve shells for seafood traceability and environmental monitoring studies. Here, we present a dataset of 297 measurements of REE and Y abundances by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) from two species (Crassostrea gigas and Ostrea edulis). We measured a total of 49 oyster specimens from six locations in France (Atlantic Ocean and Mediterranean Sea). Our study reports that there is no significant difference in concentrations from shell parts corresponding to winter and summer periods for both species. Moreover, interspecific vital effects are reported from specimens from both species and from the same locality. REE and Y profiles as well as t-distributed stochastic neighbour embedding processing (t-SNE; a discriminant statistical method) indicate that REE and Y measurements from C. gigas shells can be discriminated from one locality to another, but this is not the case for O. edulis, which presents very similar concentrations in all studied localities. Therefore, provenance studies using bivalve shells based on REEs and Y have to first be tested for the species. Other methods have to be investigated to be able to find the provenance of some species, such as O. edulis.

U–Pb age determination for zircons using laser ablation-ICP-mass spectrometry equipped with six multiple-ion counting detectors

2017 ◽  
Vol 32 (1) ◽  
pp. 88-95 ◽  
Author(s):  
Kentaro Hattori ◽  
Shuhei Sakata ◽  
Michitaka Tanaka ◽  
Yuji Orihashi ◽  
Takafumi Hirata
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Inductively Coupled Plasma ◽  
Age Determination ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Icp Mass Spectrometry ◽  
Age Determinations

Precise zircon U–Pb age determinations have been made on Plešovice zircon using laser ablation-multiple ion counting-inductively coupled plasma-mass spectrometry (LA-MIC-ICP-MS).

Single Particle Inductively Coupled Plasma Mass Spectrometry: Investigating Nonlinear Response Observed in Pulse Counting Mode and Extending the Linear Dynamic Range by Compensating for Dead Time Related Count Losses on a Microsecond Timescale

2019 ◽  
Author(s):  
Ingo Strenge ◽  
Carsten Engelhard
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
Nonlinear Response ◽  
Dynamic Range ◽  
Dead Time ◽  
Inorganic Nanoparticles ◽  
Linear Dynamic Range ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

<p>The article demonstrates the importance of using a suitable approach to compensate for dead time relate count losses (a certain measurement artefact) whenever short, but potentially strong transient signals are to be analysed using inductively coupled plasma mass spectrometry (ICP-MS). Findings strongly support the theory that inadequate time resolution, and therefore insufficient compensation for these count losses, is one of the main reasons for size underestimation observed when analysing inorganic nanoparticles using ICP-MS, a topic still controversially discussed.</p>

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