The Coupled Re-Os and Pt-Os Systematics: A Theoretical Consideration

The 190Pt-l86Os system should be a unique tracer for mantle processes because both Pt and Os are concentrated in the mantle. The 190Pt-186Os system will also be a good supplement to the 187Re-187Os system for dating and tracing mantle processes because the 190Pt-186Os system is not so easily contaminated by crustal materials as the 187Re-187Os system. In turn, the application of the 187Re-187Os system to Pt-enriched materials uncontaminated by crustal materials will indirectly refine the half life of 190Pt. The 190Pt-186Os system will be a promising tracer and chronometer when the decay constant of 190Pt is refined. In the coupled 187Re-187Os and 190Pt-186Os sys-tematics, an 186Os*/190Pt-187Os*/187Re concordia diagram similar to the 206pb*/238U-208Pb*/232 Th concordia can be constructed. In such a concordia diagram, a date will be obtained so long as the 190Pt-186Os system remains closed even if the l87Re-187Os system is contaminated by crustal materials. In addition, for the coupled 190Pt-186Os and 187R