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Radionuclides, cooling times, energies of 1'-rays and type of detector used
Source publication
Instrumental neutron activation analysis, atomic absorption spectrometry and conventional methods were used on five USGS Geochemical Exploration Reference Materials: GXR-1, 2, 3, 4 and 6. The concentrations of 35 elements are reported and compared with available literature values. In general the agreement is good.
Citations
... This system has a FWHM of 450 eV at 5.9 keV, 750 eV at 60 keV, and 2100 eV at 122 keV. More details of the analytical method can be found in other studies (Gouveia et al., 1994;Gouveia & Prudêncio, 2000;Marques et al., 2021;Prudêncio et al., 2016). ...
This paper presents the geochemical and petrographic characterization, along with the macroscopic observations, of several cherts from the central region of the Mediterranean Iberia. To determine the microfacies and microtextural features, thin-section samples were analyzed using polarizing light microscopy (PLM) and scanning electron microscopy coupled with an energy-dispersive X-ray spectrometer (SEM/EDX). Geochemical analyses were performed using instrumental neutron activation analyses (INAA). With the data, multivariate statistical analysis by means of hierarchical cluster analysis (HCA) and principal components analysis (PCA) was applied to the chemical variables to identify clusters among the chert samples. The results showed different geochemical features between cherts concerning major, minor, and trace elements. Archaeological samples from different sites demonstrated lithic raw material circulation and, thus, human mobility in the central region of Mediterranean Iberia during the Middle and Upper Paleolithic.
... Whole-rock S contents were measured by using a gravimetric method and IR absorption with the detection limits ~0.01%. The analytical precisions are ~4% of amount present for S. The values of standards GXR-1 and GXR-3 are from [75] and given in Table A4. ...
The Baixintan mafic-ultramafic intrusion in the Dananhu-Tousuquan arc of the Eastern Tianshan orogenic belt is composed of lherzolite, olivine gabbro, and gabbro. Olivine gabbros contain zircon grains with a U-Pb age of 276.8 ± 1.1 Ma, similar to the ages of other Early Permian Ni-Cu ore-bearing intrusions in the region. The alkaline-silica diagrams, AFM diagram, together with the Ni/Cu-Pd/Ir diagram, indicate that the parental magmas for the Baixintan intrusion were likely high-Mg tholeiitic basaltic in composition. The Cu/Pd ratios, the relatively depleted PGEs and the correlations between them demonstrate that the parental magmas had already experienced sulfide segregation. The lower CaO content in pyroxenites compared with the Duke Island Alaskan-type intrusion and the composition of spinels imply that Baixintan is not an Alaskan-type intrusion. By comparing the Baixintan intrusion with other specific mafic-ultramafic intrusions, this paper considers that the mantle source of the Baixintan intrusion is metasomatized by subduction slab-derived fluids’ components, which gives rise to the negative anomalies of Nb, Ti, and Ta elements. Nb/Yb-Th/Yb, Nb/Yb-TiO2/Yb, and ThN-NbN plots show that the Baixintan intrusion was emplaced in a back-arc spreading environment and may be related to a mantle plume.
... Reference materials included two materials used by Actlabs (including OREAS 45P ferruginous soil) and three project in-house reference materials developed from soils derived from calcarenite, basalt and pyroxenite respectively, and which were analysed by a number of commercial laboratories to determine expected aqua regiaextractable ICP-MS element values. INAA analyses were monitored using soil reference material USGS GXR-6 (Gouveia et al., 1994) and four Actlabs in-house till reference materials. Field-portable XRF analyses were monitored using synthetic reference material SynTerm 12 (Cohen and Beck, 1995) and USGS GXR-6. ...
Rare earth elements (REEs) are used as indicators or proxies for a range of geological and mineralogical processes due to their unique geochemical characteristics. Total and aqua regia- extractable concentrations of REEs and 57 other elements have been determined for 5,350 soil samples as part of the high sampling density Geochemical Atlas of Cyprus. The bedrock geology of Cyprus is dominated by the sequence of ultramafic to mafic units formed at a spreading ridge and subsequently obducted to form the Troodos Ophiolite (TO), and the surrounding carbonate-rich Circum-Troodos Sedimentary Sequence (CTSS) deposited in environments ranging from deep marine to sub-aerial. Total and aqua regia-extractable REE patterns are similar for each element and are largely controlled by parent lithology. Soil-to-rock REE ratios are generally elevated in the TO units (>4 for LREEs and 1.5–3 for HREEs) due to loss of more mobile elements during weathering but are close to 1 in the CTSS units. HREEs are more elevated than LREEs in soils derived from TO units with upper continental crust-normalised patterns indicating the main source to be pyroxenes and zircon. Trace element trends indicate REEs in the CTSS were largely derived from detrital material shedding off the TO and deposited in progressively shallowing basins under largely anoxic conditions (absence of Ce4+ anomalies), with a minor contribution from seawater via adsorption onto secondary Fe+Mn oxides or co-precipitation with carbonates. Heavy mineral-associated elements such as Zr and Th display a relative consistent ratio in the CTSS soils. Peak HREE concentrations occur in the mafic cumulates and intrusives where the median LaUCC/YbUCC is ∼0.12, whereas in CTSS units the LREEs are more elevated with a median LaUCC/YbUCC ∼0.7. Due to the strong lithogeochemical controls, soil REE spatial patterns reflect even subtle mineralogical variations within the various TO units, the location of major transform faults and other structures, and areas that have been affected by hydrothermal alteration.
... Analysis and field NaI gamma spectrometry, as-sampled and drained water content measurements, sample and measurement geometries, locations and burial depths (for more detailed description of the methods see Burbidge et al., Submitted, and Gouveia et al., 1994). ...
A large earthquake shook the offshore region of Portugal in November 1st 1755 with an estimated magnitude of 8.5 +/- 0.3 in the Richter scale. It lead to the massive destruction of the city of Lisbon, which was followed by intense fires. Although most of the detailed consequences of the earthquake and tsunami focused in Lisbon, the effect of tsunami destruction was also reported in other locations along the Peninsula coasts and Morocco. At Setubal, located 30 km to the south of Lisbon in the Sado estuary, evidences of inundation were also documented, reporting wave heights that reached a first floor height. Despite the magnitude of the inundation in the interior of the estuary, there has not been reported any evidence of the impact of this event on the estuarine shorelines. In order to understand the consequences of such a wave on the sandy shores of the region, we explore the inlet shoreline and seaward exposed region of the estuary, the Troia peninsula. To do so, we integrate multiple types of data and information: dune ridge position were extracted from aerial photographs, shorelines from the historical maps, shoreline progradation rates, Ground Penetrating Radar profiles and optically stimulated dating of barrier sediments. This information allows us to reconstruct the shoreline following the tsunami, documenting a greater impact towards the inlet where the water flow concentrate as it entered the estuary. The impact of the tsunami in Troia peninsula translates on the erosion of about 1000 years of barrier deposits within the spit end.
... Quality control/assurance of the data was applied using the repetitive processing of several aliquots of quartz blanks, sample replicates and the geochemical reference materials GXR-3 and GXR-6 (Gouveia et al., 1994). Replicate determinations agreed to within ±5% and, recoveries of certified reference materials were in the 95-105% range. ...
There is a rising need for scientifically sound and quantitative as well as simple, rapid, cheap and readily available soil testing procedures. The purpose of this study was to explore selected soft drinks (Coca-Cola Classic®, Diet Coke®, Coke Zero®) as indicators of bioaccessible uranium and other trace elements (As, Ce, Cu, La, Mn, Ni, Pb, Th, Y, Zn) in contaminated soils of the Mary Kathleen uranium mine site, Australia. Data of single extraction tests using Coca-Cola Classic®, Diet Coke® and Coke Zero® demonstrate that extractable arsenic, copper, lanthanum, manganese, nickel, yttrium and zinc concentrations correlate significantly with DTPA- and CaCl₂-extractable metals. Moreover, the correlation between DTPA-extractable uranium and that extracted using Coca-Cola Classic® is close to unity (+0.98), with reduced correlations for Diet Coke® (+0.66) and Coke Zero® (+0.55). Also, Coca-Cola Classic® extracts uranium concentrations near identical to DTPA, whereas distinctly higher uranium fractions were extracted using Diet Coke® and Coke Zero®. Results of this study demonstrate that the use of Coca-Cola Classic® in single extraction tests provided an excellent indication of bioaccessible uranium in the analysed soils and of uranium uptake into leaves and stems of the Sodom apple (Calotropis procera). Moreover, the unconventional reagent is superior in terms of availability, costs, preparation and disposal compared to traditional chemicals. Contaminated site assessments and rehabilitation of uranium mine sites require a solid understanding of the chemical speciation of environmentally significant elements for estimating their translocation in soils and plant uptake. Therefore, Cola soft drinks have potential applications in single extraction tests of uranium contaminated soils and may be used for environmental impact assessments of uranium mine sites, nuclear fuel processing plants and waste storage and disposal facilities.
Diese Studie hat ein vollständiges Verfahren für die Messung der Sauerstoff-Isotope in Arsen-Oxianionen in natürlichen Wässern durch den Einsatz verschiedener Adsorbentien entwickelt. Experimente zum kinetischen Austausch von Sauerstoff zwischen AsO43- und Wasser haben gezeigt, dass sich das Gleichgewicht bei verschiedenen pH-Bedingungen und Temperaturen in sehr kurzer Zeit einstellt. © 2014 Karlsruher Institut fur Technologie (KIT). All rights reserved.
The separation of99Mo from low-enriched uranium (LEU, 19.5%235U) targets was evaluated using natural uranium (NU) and non-radioactive tracers. Neutron activation analysis was used to determine (1) the efficiency of molybdenum recovery and (2) the decontamination factor of numerous fission product elements from the molybdenum product. Using NU and non-radioactive elements simplified procedures and allowed tests to be completed in a fume hood instead of a shielded cell. During activation of the non-radioactive tracers, uranium fission occurs, which can interfere with subsequent gamma-ray analysis. A comparison was made of the interferences caused by these fission products from both NU and LEU.
