{"_buckets": {"deposit": "5858ba02-cdfa-4755-b691-83c2de7b173b"}, "_deposit": {"id": "18705", "owners": [], "pid": {"revision_id": 0, "type": "depid", "value": "18705"}, "status": "published"}, "_oai": {"id": "oai:nagoya.repo.nii.ac.jp:00018705"}, "item_10_biblio_info_6": {"attribute_name": "\u66f8\u8a8c\u60c5\u5831", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "2011-05", "bibliographicIssueDateType": "Issued"}, "bibliographicPageEnd": "202", "bibliographicPageStart": "199", "bibliographicVolumeNumber": "473", "bibliographic_titles": [{"bibliographic_title": "Nature"}]}]}, "item_10_description_4": {"attribute_name": "\u6284\u9332", "attribute_value_mlt": [{"subitem_description": "A melt has greater volume than a silicate solid of the same composition. But this difference diminishes at high pressure, and the possibility that a melt sufficiently enriched in the heavy element iron might then become more dense than solids at the pressures in the interior of the Earth (and other terrestrial bodies) has long been a source of considerable speculation1, 2. The occurrence of such dense silicate melts in the Earth\u0027s lowermost mantle would carry important consequences for its physical and chemical evolution and could provide a unifying model for explaining a variety of observed features in the core\u2013mantle boundary region3. Recent theoretical calculations4 combined with estimates of iron partitioning between (Mg,Fe)SiO3 perovskite and melt at shallower mantle conditions5, 6, 7 suggest that melt is more dense than solids at pressures in the Earth\u0027s deepest mantle, consistent with analysis of shockwave experiments8. Here we extend measurements of iron partitioning over the entire mantle pressure range, and find a precipitous change at pressures greater than ~76\u2009GPa, resulting in strong iron enrichment in melts. Additional X-ray emission spectroscopy measurements on (Mg0.95Fe0.05)SiO3 glass indicate a spin collapse around 70\u2009GPa, suggesting that the observed change in iron partitioning could be explained by a spin crossover of iron (from high-spin to low-spin) in silicate melt. These results imply that (Mg,Fe)SiO3 liquid becomes more dense than coexisting solid at ~1,800\u2009km depth in the lower mantle. Soon after the Earth\u0027s formation, the heat dissipated by accretion and internal differentiation could have produced a dense melt layer up to ~1,000\u2009km in thickness underneath the solid mantle. We also infer that (Mg,Fe)SiO3 perovskite is on the liquidus at deep mantle conditions, and predict that fractional crystallization of dense magma would have evolved towards an iron-rich and silicon-poor composition, consistent with seismic inferences of structures in the core\u2013mantle boundary region.", "subitem_description_type": "Abstract"}]}, "item_10_identifier_60": {"attribute_name": "URI", "attribute_value_mlt": [{"subitem_identifier_type": "DOI", "subitem_identifier_uri": "http://dx.doi.org/10.1038/nature09940"}, {"subitem_identifier_type": "HDL", "subitem_identifier_uri": "http://hdl.handle.net/2237/20801"}]}, "item_10_publisher_32": {"attribute_name": "\u51fa\u7248\u8005", "attribute_value_mlt": [{"subitem_publisher": "nature publishing group"}]}, "item_10_select_15": {"attribute_name": "\u8457\u8005\u7248\u30d5\u30e9\u30b0", "attribute_value_mlt": [{"subitem_select_item": "author"}]}, "item_10_source_id_7": {"attribute_name": "ISSN", "attribute_value_mlt": [{"subitem_source_identifier": "0028-0836", "subitem_source_identifier_type": "ISSN"}]}, "item_creator": {"attribute_name": "\u8457\u8005", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "Nomura, Ryuichi"}], "nameIdentifiers": [{"nameIdentifier": "54534", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Ozawa, Haruka"}], "nameIdentifiers": [{"nameIdentifier": "54535", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Tateno, Shigehiko"}], "nameIdentifiers": [{"nameIdentifier": "54536", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Hirose, Kei"}], "nameIdentifiers": [{"nameIdentifier": "54537", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Hernlund, John"}], "nameIdentifiers": [{"nameIdentifier": "54538", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Muto, Shunsuke"}], "nameIdentifiers": [{"nameIdentifier": "54539", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Ishii, Hirofumi"}], "nameIdentifiers": [{"nameIdentifier": "54540", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Hiraoka, Nozomu"}], "nameIdentifiers": [{"nameIdentifier": "54541", "nameIdentifierScheme": "WEKO"}]}]}, "item_files": {"attribute_name": "\u30d5\u30a1\u30a4\u30eb\u60c5\u5831", "attribute_type": "file", "attribute_value_mlt": [{"accessrole": "open_date", "date": [{"dateType": "Available", "dateValue": "2018-02-21"}], "displaytype": "detail", "download_preview_message": "", "file_order": 0, "filename": "Nature_2011.pdf", "filesize": [{"value": "6.5 MB"}], "format": "application/pdf", "future_date_message": "", "is_thumbnail": false, "licensetype": "license_free", "mimetype": "application/pdf", "size": 6500000.0, "url": {"label": "Nature_2011.pdf", "url": "https://nagoya.repo.nii.ac.jp/record/18705/files/Nature_2011.pdf"}, "version_id": "e9303245-3bf9-46b3-91d5-95d60d7cdf2e"}]}, "item_keyword": {"attribute_name": "\u30ad\u30fc\u30ef\u30fc\u30c9", "attribute_value_mlt": [{"subitem_subject": "Earth science", "subitem_subject_scheme": "Other"}]}, "item_language": {"attribute_name": "\u8a00\u8a9e", "attribute_value_mlt": [{"subitem_language": "eng"}]}, "item_resource_type": {"attribute_name": "\u8cc7\u6e90\u30bf\u30a4\u30d7", "attribute_value_mlt": [{"resourcetype": "journal article", "resourceuri": "http://purl.org/coar/resource_type/c_6501"}]}, "item_title": "Spin crossover and iron-rich silicate melt in the Earth\u2019s deep mantle", "item_titles": {"attribute_name": "\u30bf\u30a4\u30c8\u30eb", "attribute_value_mlt": [{"subitem_title": "Spin crossover and iron-rich silicate melt in the Earth\u2019s deep mantle"}]}, "item_type_id": "10", "owner": "1", "path": ["320/321/322"], "permalink_uri": "http://hdl.handle.net/2237/20801", "pubdate": {"attribute_name": "\u516c\u958b\u65e5", "attribute_name_i18n": "\u516c\u958b\u65e5", "attribute_value": "2014-11-18"}, "publish_date": "2014-11-18", "publish_status": "0", "recid": "18705", "relation": {}, "relation_version_is_last": true, "title": ["Spin crossover and iron-rich silicate melt in the Earth\u2019s deep mantle"], "weko_shared_id": null}