New Insights into Pb Isotope Fingerprinting of U-Mine Material Dissemination in the Environment: Pb Isotopes as a Memory Dissemination Tracer

Abstract

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An integrated approach combining soil profile, records and tree ring analysis to identify the origin of environmental contamination in a former uranium mine (Rophin, France)

“…The A64 sample was used for the geochemical background end-member and for the intercept of the linear regression in Figure 4a as the 207 Pb/ 206 Pb radiogenic end-member. By applying the mixing model and taking the Pb atomic abundances into account, it is possible to correctly calculate the contribution of radiogenic lead (k, in %) to the total lead for each sample (Gourgiotis et al, 2020).…”

“…Weathering and erosion of the local bedrock, which is often granitic in the case of French U mines, can also play a major role in increasing these concentration levels. High U contents have in fact already been documented at sites not heavily impacted by mining activities, such as Alpine soils (up to 4,000 mg.kg -1 ), or by ground and surface waters, where the surrounding bedrock mainly consists of crystalline rocks that commonly contain trace amounts of U (Gourgiotis et al, 2020).…”

“…It should be noted that excessive use of 210 Pb is unfortunately impossible in a U mining context (Reyss 6 et al, 2016). The origin of these U markings, whether natural or anthropogenic, can then also be traced by means of lead isotopy (Bollhöfer, 2012;Bollhöfer et al, 2006;Cuvier et al, 2016;Gourgiotis et al, 2020).…”

Pushing Limits of ICP–MS/MS for the Determination of Ultralow 236U/238U Isotope Ratios

“…As no certified material is available for lower 236 U/ 238 U isotope ratios, three environmental samples previously characterized by the Vienna Environmental Research Accelerator (VERA) using an Accelerator Mass Spectrometer (AMS) were used to validate the method for lower ratios. Two sediment samples C2–5 and C2–30 were collected in a wetland draining a former uranium mine. , These samples are highly enriched in uranium with concentrations of about 4500 μg·g –1 and about 2500 μg·g –1 , respectively, and 236 U/ 238 U isotope ratios were determined by AMS measurements to a level of (3.57 ± 0.26) × 10 –10 and (3.50 ± 0.19) × 10 –10 , respectively. Uranium concentrations in the measured solution are 50 μg·g –1 for C2–5 and 40 μg·g –1 for C2–30.…”

Nickel Isotope Fractionation As an Indicator of Ni Sulfide Precipitation Associated with Microbially Mediated Sulfate Reduction

“…Metal-stable isotope analysis has become a valuable tool in the field of environmental geochemistry with applications focusing on tracing the source and cycling of metals in the environment. − …”