Phase transitions in MgSiO3 post-perovskite in super-Earth mantles Umemoto, Koichiro Wentzcovitch, Renata Wu, Shunqing Ji, Min Wang, Cai-Zhuang Ho, Kai-Ming
dc.contributor.department Ames Laboratory
dc.contributor.department Physics and Astronomy 2018-08-30T03:45:24.000 2020-06-29T23:21:22Z 2020-06-29T23:21:22Z 2018-11-15 2017-11-15
dc.description.abstract <p>The highest pressure form of the major Earth-forming mantle silicate is MgSiO3 post-perovskite (PPv). Understanding the fate of PPv at TPa pressures is the first step for understanding the mineralogy of super-Earths-type exoplanets, arguably the most interesting for their similarities with Earth. Modeling their internal structure requires knowledge of stable mineral phases, their properties under compression, and major element abundances. Several studies of PPv under extreme pressures support the notion that a sequence of pressure induced dissociation transitions produce the elementary oxides SiO2 and MgO as the ultimate aggregation form at ∼3 TPa. However, none of these studies have addressed the problem of mantle composition, particularly major element abundances usually expressed in terms of three main variables, the Mg/Si and Fe/Si ratios and the Mg#, as in the Earth. Here we show that the critical compositional parameter, the Mg/Si ratio, whose value in the Earth's mantle is still debated, is a vital ingredient for modeling phase transitions and internal structure of super-Earth mantles. Specifically, we have identified new sequences of phase transformations, including new recombination reactions that depend decisively on this ratio. This is a new level of complexity that has not been previously addressed, but proves essential for modeling the nature and number of internal layers in these rocky mantles.</p>
dc.identifier archive/
dc.identifier.articleid 1211
dc.identifier.contextkey 12715640
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath ameslab_manuscripts/209
dc.language.iso en
dc.relation.ispartofseries IS-J 9482
dc.source.bitstream archive/|||Fri Jan 14 22:30:06 UTC 2022
dc.source.uri 10.1016/j.epsl.2017.08.032
dc.subject.disciplines Astrophysics and Astronomy
dc.subject.disciplines Cosmochemistry
dc.subject.disciplines Geochemistry
dc.subject.disciplines Mineral Physics
dc.subject.disciplines Physics
dc.subject.keywords pressure-induced phase transition
dc.subject.keywords postperovskite
dc.subject.keywords super-Earth
dc.subject.keywords first principles
dc.title Phase transitions in MgSiO3 post-perovskite in super-Earth mantles
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isOrgUnitOfPublication 25913818-6714-4be5-89a6-f70c8facdf7e
relation.isOrgUnitOfPublication 4a05cd4d-8749-4cff-96b1-32eca381d930
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