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

CSEDI 合作研究：190Pt-186Os 系统作为核幔相互作用测试：第二阶段

• 批准号: 9709792
• 负责人: John Morgan
• 金额: $ 5.5万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 1998-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9709792&HistoricalAwards=false
• 关键词: CSEDI; Collaborative; Reseach; 190Pt; 186Os

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. ***

小行星9709792 羽流可能夹带一些外核物质的假设将通过检查羽流衍生岩石的187 Re-187 Os-190 Pt-186 Os系统学来检验。 190 Pt会衰变为186 Os，因此外核的Pt/Os比应该远大于质子，以小行星核作为类比。 有限的数据表明，与Re-Os系统不同，地壳再循环可能不会显著影响混合地幔源的Pt/Os比。 本研究的主要目的是：1）精确测量Pb-Os关系表明有非地壳187 Os富集物质参与的多种潜在地幔柱成因岩石的186 Os/188 Os，并评估186 Os和187 Os富集之间是否存在正相关关系。 2)精确和准确地测量各种地幔和地壳物质中可能再循环到地幔中的Pt和Pt/Os的浓度。 这方面的研究的目的是证实或否定的初步证据表明，地壳物质再循环到地幔的幔-壳混合物的Pt/Os的比例几乎没有影响。 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相互作用。 ***