The composition of mantle plumes and the deep Earth
The composition of mantle plumes and the deep Earth
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DOI：
10.1016/j.epsl.2016.03.023
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发表时间：
2016-06
影响因子：
5.3
通讯作者：
A. Hastie;J. Fitton;A. Kerr;I. McDonald;Antje Schwindrofska;K. Hoernle
中科院分区：
文献类型：
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作者：
A. Hastie;J. Fitton;A. Kerr;I. McDonald;Antje Schwindrofska;K. Hoernle
确定地球深部地幔和随后上升的地幔柱的组成和地球化学多样性至关重要，这样我们就可以更好地了解地球原始地幔储层最初是如何形成的，以及它们在过去46亿年中是如何演变的。地幔柱在地球表面产生大量喷发，关于地幔柱成分的进一步数据对于充分了解地球水圈和大气层的演变以及与可能导致大规模灭绝事件的表面环境变化的联系也至关重要。在这里，我们提出了新的主要和微量元素和Sr-Nd-Pb-Hf同位素数据的玄武岩库拉考，加勒比大火成岩省的一部分。从这些和文献数据，我们计算相结合的主要和微量元素组成的地幔柱产生的加勒比和Ontong Java大火成岩省，并使用质量平衡，以确定地球的下地幔的组成。不兼容的元素和同位素结果表明，地幔柱有广泛独特的亏损和富集的成分，除了众多的地幔水库已经在文献中提出，代表大行星尺度的地球化学异质性在地球深部地幔，是类似于非南极散装硅酸盐地球成分。
Determining the composition and geochemical diversity of Earth's deep mantle and subsequent ascending mantle plumes is vital so that we can better understand how the Earth's primitive mantle reservoirs initially formed and how they have evolved over the last 4.6 billion years. Further data on the composition of mantle plumes, which generate voluminous eruptions on the planet's surface, are also essential to fully understand the evolution of the Earth's hydrosphere and atmosphere with links to surface environmental changes that may have led to mass extinction events. Here we present new major and trace element and Sr–Nd–Pb–Hf isotope data on basalts from Curacao, part of the Caribbean large igneous province. From these and literature data, we calculate combined major and trace element compositions for the mantle plumes that generated the Caribbean and Ontong Java large igneous provinces and use mass balance to determine the composition of the Earth's lower mantle. Incompatible element and isotope results indicate that mantle plumes have broadly distinctive depleted and enriched compositions that, in addition to the numerous mantle reservoirs already proposed in the literature, represent large planetary-scale geochemical heterogeneity in the Earth's deep mantle that are similar to non-chondritic Bulk Silicate Earth compositions.