The Re-Os ages of arsenopyrite indicate that there were at least two distinct periods of gold deposition in the Meguma terrane coinciding with widespread tectonothermal events: regional deformation and metamorphism associated with Acadian orogenesis, and widespread generation of meta- and peraluminous granites and high-grade metamorphism within the basement rocks under the Meguma terrane. The Asian continent hosts some of the world’s major Phanerozoic gold deposits and gold provinces, which were formed under a variety of tectonic settings and by various geological processes ( Goldfarb et al., 2014; Zaw et al., 2007, 2014; Khomich et al., 2014 , and references therein).Both rhenium and osmium are strongly siderophilic (iron loving), while Re is also chalcophilic (sulfur loving) making it useful in dating sulfide ores such as gold and Cu-Ni deposits.This dating method is based on an isochron calculated based on isotopic ratios measured using N-TIMS (Negative – Thermal Ionization Mass Spectrometry).
Infiltration of xenoliths by their commonly Re-rich magma alters the true elemental Re/Os ratios.
In this regard, the Re–Os system to study the geochemical evolution of mantle rocks and in defining the chronology of mantle differentiation is extremely helpful.
Peridotite xenoliths which are thought to sample the upper mantle sometimes contain supra-chondritic Os-isotopic ratios.
Despite this application mainly being associated with the economic extraction of minerals, it can be employed by the oil and gas industry to date the formation of disseminated sulphide minerals within basement rocks and so the basement itself.
Moreover, when these minerals are found in fractures it can be used to provide a minimum date for when the fracture network was open.