CSEDI Collaborative Reseach: The 190Pt-186Os System as a Test of Core-Mantle Interaction: Phase II

9709792摩根关于羽流可能夹带某些外核物质的假设将通过检验187Re-187Os和190Pt186Os的耦合系统学来检验。190Pt衰变到186Os，因此以小行星核为类比，外核的Pt/Os应该比球粒陨石大得多。有限的数据表明，与Re-Os系统不同，地壳再循环可能不会对混合地幔来源的铂/Os比率产生重大影响。这项研究的目的是：1)精确测量各种潜在的热柱成因岩石的186Os/188Os，其中Pb-Os关系表明它们参与了非地壳富187Os物质的参与，并评估186Os和187Os之间是否存在正相关关系。2)准确、准确地测量各种地幔和可能再循环到地幔中的地壳物质中的铂和铂/Os的浓度。这方面研究的目的是确认或否认初步证据，即地壳物质进入地幔的再循环对地幔-地壳混合物的铂/Os比值影响不大。这项研究的最终结果可能是更好地了解地球外核和下地幔之间是否存在化学作用。***

9709792 Morgan The hypothesis that plumes may entrain some outer core material will be tested by examining the coupled 187Re-187Os 190Pt-186Os systematics of plume-derived rocks. 190Pt decays to 186Os, so the Pt/Os of the outer core should be much greater than chondritic, using asteroidal cores as analogs. Limited data suggest that, unlike with the Re-Os system, crustal recycling would likely not significantly affect the Pt/Os ratio of a mixed mantle source. The objectives of this study are to: 1) Precisely measure the 186Os/188Os of a variety of potentially plume-derived rocks for which Pb-Os relations suggest the involvement of non-crustal 187Os-enriched materials, and assess if there is a positive relation between 186Os and 187Os enrichment. 2) Precisely and accurately measure the concentrations of Pt and Pt/Os in a variety of mantle and crustal materials that may be recycled into the mantle. The goal of this aspect of the research is to confirm or deny the preliminary evidence that suggests recycling of crustal materials into the mantle little affects the Pt/Os ratio of mantle-crust mixtures. The ultimate result of this study may be a better understanding of whether there is chemical interaction between the Earth's outer core and lower mantle. ***