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Platinum group elements in a 3.5 Ga nickel‐iron occurrence: Possible evidence of a deep mantle origin
The Bon Accord (BA) Ni-Fe deposit occurs in chemically depleted ultramafic rocks of the circa 3.5 Ga Jamestown ophiolite complex in the Barberton greenstone belt of the Kaapvaal craton, South Africa.Expand
Chemostratigraphy across the Cretaceous-Tertiary Boundary and a Critical Assessment of the Iridium Anomaly
The elevated concentration of iridium-one of the platinum-group elements (PGE)-at the Cretaceous-Tertiary boundary is still the most generally accepted evidence that a large bolide struck the earthExpand
Radiocarbon and tritium evidence for direct rain recharge to ground waters in the northern Kalahari
THE Kalahari, a flat and sand-covered region of more than 600,000 km2 (Fig. 1), has long been classified as a desert because of the virtual absence of surface waters in the form of springs orExpand
Abstract Natural diamond is characterised in terms of features in the infra-red and ultra-violet spectra. Additionally electron spin resonance, X-ray diffraction and topography, cathodoluminescence,Expand
Optical effects in carbon-ion irradiated diamond
Abstract Single crystals of diamond were irradiated with carbon ions up to integral fluences of about 10 17 C/cm 2 . In order to produce homogeneous damage profiles over a depth of 1 μ m the samplesExpand
Time sequence particulate sampling and nuclear analysis
A review is given of a series of time-sequence sampling devices for atmospheric particles. The samplers considered are all designed around the sensitive analytical capabilities of Particle InducedExpand
Chemical composition of groundwaters in the vast Kalahari flatland
Abstract The Kalahari thirst land encompasses 6 · 10 5 km 2 of flat, sand covered, area that is ideal for the study of the geochemical evolution of waters in inland and arid terrain. Several factorsExpand
Corrosion Behaviour of Ion Implanted Wc–Co and Wc–Ni Alloys in Acid and Chloride Containing Media
Abstract Alloys of WC–Co (6-30 wt-%Co) and WC–Ni (6-15 wt-%Ni) were implanted with chromium, molybdenum, and titanium ions at fluences from 1 × 1021 to 4 × 1021 ions m-2. Their corrosion resistanceExpand
Distribution and degree of occurrence of aflatoxin in groundnuts and groundnut products.
Die mate van aflatoksienbesmetting van 501 grondboonmonsters van die oes vir 1963 en 943 van die oes van 1964, is ondersoek om die graad van besoedeling en die verspreiding van die aangedaandeExpand
PIXE analysis of caries related trace elements in tooth enamel
Abstract PIXE analysis has been applied to a set of twenty human teeth to determine trace element concentration in enamel from areas susceptible to dental caries (mesial and distal contact points)Expand