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标题：Subduction of the primordial crust into the deep mantle
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作者：Hiroki Ichikawa ; Hiroki Ichikawa ; Steeve Gréaux 等
期刊名称：Geoscience Frontiers
印刷版ISSN：1674-9871
出版年度：2017
卷号：8
期号：2
页码：347-354
DOI：10.1016/j.gsf.2016.08.003
语种：English
出版社：Elsevier
摘要：Abstract The primordial crust on the Earth formed from the crystallization of the surface magma ocean during the Hadean. However, geological surveys have found no evidence of rocks dating back to more than 4 Ga on the Earth's surface, suggesting the Hadean crust was lost due to some processes. We investigated the subduction of one of the possible candidates for the primordial crust, anorthosite and KREEP crust similar to the Moon, which is also considered to have formed from the crystallization of the magma ocean. Similar to the present Earth, the subduction of primordial crust by subduction erosion is expected to be an effective way of eliminating primordial crust from the surface. In this study, the subduction rate of the primordial crust via subduction channels is evaluated by numerical simulations. The subduction channels are located between the subducting slab and the mantle wedge and are comprised of primordial crust materials supplied mainly by subduction erosion. We have found that primordial anorthosite and KREEP crust of up to ∼50 km thick at the Earth's surface was able to be conveyed to the deep mantle within 0.1-2 Gy by that mechanism. Graphical abstract Display Omitted Highlights • Subduction rate of the primordial anorthosite and KREEP crust is evaluated. • Subduction channel is modeled by 1-D finite difference method. • 50 km thickness of the crust was able to be conveyed to deep mantle within 0.1–2 Ga.
关键词：KeywordsenPrimordial crustAnorthositeKREEPSubduction erosionSubduction channel