Progress, open questions and application prospects of analytical techniques for refractory elements and representative radioisotope systems

The parent and daughter of Pt-Os, Re-Os and Hf-W isotopic systems (i. e. Pt, Os, Re, Hf and W) and other platinum group elements ( PGEs ) are refractory in chemical properties, which are named collectively as refractory elements and refractory elemental radiogenic isotope systems in present paper. Refractory elements and their representative radiogenic isotope systems can not only directly determine the age of metal deposits, oil and gas reservoirs and sedimentary rock series, but also effectively trace the core-mantle reaction in the deep earth, which makes them irreplaceable geochemical tools. This paper reviews the research progress of PtOs, Re-Os and Hf-W isotopic systems and PGE elemental analysis technology. It is pointed out that : (1) the Re-Os isotopic dating error is still large, so it is necessary to optimize and improve the analysis technology in order to greatly improve the accuracy and success rate of Re-Os isotopic dating. (2) The analysis technology of Pt-Re-Os and W isotopes needs to simplify the cumbersome chemical separation process and improve the efficiency of instrumental analyzing. In the meantime, it is suggested to establish new chemical separation and instrumental analysis methods. Only by realizing accurate analysis of samples with very low content of Pt, Re, Os and W, it is possible to effectively trace material recycling processes in the deep earth. (3) The analysis technology of PGE needs to be optimized, and the analysis precision still needs to be further improved. With further improvement of the analytical techniques of refractory elements and representative radiogenic isotopes, it is anticipated that these geochemical tools will be more widely used in tracing and/or dating the material recycle processes of core-mantle, mantle-mantle and crust-mantle, the precise timing and formation mechanism of metal deposits and complex petroleum systems, and the environment change during Mesoproterozoic.