Radiogenic and Stable Isotope Laboratory

Highly siderophile element and Re-Os geochemistry lab

Highly siderophile element (HSE - Os, Ir, Ru, Pd, Pt, Re, Au) and ¹⁸⁷Re-¹⁸⁷Os isotope system provide insights into the cosmochemistry and mantle-derived processes. Additionally, Re-Os system is used for geochronology of sulphide-bearing systems as well as black shales, crude oils etc.

The Re-Os (HSE) laboratory housed in Institute of Geology v.v.i., Academy of Sciences of the Czech Republic and Czech Geological Survey utilizes Re-Os (HSE) technique for the study of meteorites, mantle-derived peridotites/sulphides, mafic rocks (basalts, gabbros) and Re-Os geochronology of molybdenite. Other use for the study of crustal-derived ore systems and black shales is current under development. The chemistry and Re, Ir, Ru, Pd, Pt measurements are undertaken in the clean-lab and ICP-MS lab of the Institute of Geology v.v.i., Academy of Sciences of the Czech Republic, respectively. The Os isotopic measurements are carried out in Czech Geological Survey.

Methods

Highly siderophile element concentration data and Os isotopic data are obtained using standard techniques (e.g., Ackerman et al., 2009; Puchtel et al., 2008). For silicates, whole-rock powders (~ 1-2 g) are mixed with Re-Os (mixed ¹⁸⁵Re-¹⁹⁰Os) and ¹⁹¹Ir-⁹⁸Ru-¹⁰⁵Pd-¹⁹⁴Pt spikes and dissolved in pre-cleaned Carius tubes using 4 mL concentrated HCl and 6 mL concentrated HNO₃ at 280°C for 2-3 days (Shirey and Walker, 1995). Osmium is separated from aqua regia by solvent extraction to CCl₄ and/or CHCl₃ and back reduction to HBr (Cohen and Waters, 1996). The final fraction is purified by microdistillation (Birck et al., 1997). Iridium, Ru, Pt, Pd and Re are separated by anion exchange chromatography using AG 1x8 resin (BioRad). Osmium concentrations and isotopic ratios are obtained using N-TIMS (Creaser et al., 1991; Völkening et al., 1991) technique. Samples are analyzed as OsO₃- using a Finnigan MAT 262 thermal ionization spectrometer (Czech Geological Survey) with Faraday cups in static or dynamic mode, or using an electron multiplier in a peak hopping mode. Iridium, Ru, Pt, Pd and Re are analyzed using a Thermo-Finnigan sector field ICP-MS (Element2).

In the case of your interest in the analyses, please contact ackermangli [dot] cas [dot] cz (us).