Re os age dating

When oil is formed from a source rock, a proportion of the Re and Os from the source rock is transferred to the oil, thus one can date the formation process using the Re - Os geochronometer.

Furthermore, as Re and Os have been inherited from the source rocks, Os isotopes can be employed to correlate an oil with its source.

Rhenium-Osmium dating is carried out by the isochron dating method.

Isochrons are created by analysing several samples believed to have formed at the same time from a common source.

Over the years, Chemostrat has expanded the services on offer to now include more advanced isotopic techniques that so far have been used only in academia.

The information presented below briefly outlines how Chemostrat is utilising two of these techniques, i.e., the Rhenium - Osmium (Re - Os) isotopic dating technique and the Uranium - Lead (U - Pb) isotopic dating technique, to assist the petroleum industry in the goals of oil and gas exploration.

Re-Os isotopes natural hydrocarbons are directly related to source-rock Re-Os isotope character and in some cases Re-Os geochronology of hydrocarbons is possible.

The rhenium-osmium (Re-Os) dating technique is uniquely able to date directly sulfide minerals and some natural metals because both elements have strongly siderophile and chalcophile characteristics.

For sulfide minerals, Re-Os geochronology has direct application to the timing and duration of hydrothermal ore deposit formation.

Ore minerals investigated in detail include molybdenite, pyrite and arsenopyrite which have been applied to understand the origin of porphyry, Sed Ex, VMS, IOCG and Orogenic Au deposits globally.

Some key papers include: Using Re-Os isotopes to determine the deposition age of petroleum source-rock formation (organic-rich shales) is a major research theme, both in terms of technical development and application.

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).

486

Leave a Reply