{"id":13940,"date":"2017-11-28T00:20:50","date_gmt":"2017-11-27T23:20:50","guid":{"rendered":"http:\/\/karmaka.de\/?p=13940"},"modified":"2018-03-01T08:55:10","modified_gmt":"2018-03-01T07:55:10","slug":"late-metal-silicate-separation-on-the-iab-parent-asteroid-constraints-from-combined-w-and-pt-isotopes-and-thermal-modelling","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=13940","title":{"rendered":"Late metal\u2013silicate separation on the IAB parent asteroid: Constraints from combined W and Pt isotopes and thermal modelling<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"<p>Alison C. Hunt, David L. Cook, Tim Lichtenberg, Philip M. Reger, Mattias Ek, Gregor J. Golabek, Maria Sch\u00f6nb\u00e4chler<\/p>\n<p>Earth and Planetary Science Letters<br \/>\nVolume 482, 15 January 2018, Pages 490\u2013500<\/p>\n<p><a href=\"http:\/\/www.sciencedirect.com\/science\/article\/pii\/S0012821X17306702\" target=\"_blank\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br \/>\n<a href=\"https:\/\/arxiv.org\/ftp\/arxiv\/papers\/1802\/1802.10421.pdf\" target=\"_blank\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n<p>&#8220;Highlights<\/p>\n<p>\u2022    Tungsten and Pt isotopes in IAB irons are affected by neutron capture reactions.<br \/>\n\u2022    IAB iron meteorites from several sub-groups have pre-exposure \u03b5182W = \u22122.90 \u00b1 0.06.<br \/>\n\u2022    This corresponds to body-wide metal\u2013silicate separation at 6.0 \u00b1 0.8 Ma after CAI.<br \/>\n\u2022    Thermal models of interior evolution support heating by short-lived radionuclides.<br \/>\n\u2022    Models suggest the parent body accreted at \u223c1.4 Ma after CAIs with a radius >60 km.&#8221;<\/p>\n<p>&#8220;The short-lived 182Hf\u2013182W decay system is a powerful chronometer for constraining the timing of metal\u2013silicate separation and core formation in planetesimals and planets. Neutron capture effects on W isotopes, however, significantly hamper the application of this tool. In order to correct for neutron capture effects, Pt isotopes have emerged as a reliable in-situ neutron dosimeter. This study applies this method to IAB iron meteorites, in order to constrain the timing of metal segregation on the IAB parent body.<\/p>\n<p>The \u03b5182\u03b5182W values obtained for the IAB iron meteorites range from \u22123.61 \u00b1 0.10 to \u22122.73 \u00b1 0.09. Correlating \u03b5i\u03b5iPt with \u03b5182\u03b5182W data yields a pre-neutron capture \u03b5182\u03b5182W of \u22122.90 \u00b1 0.06. This corresponds to a metal\u2013silicate separation age of 6.0 \u00b1 0.8 Ma after CAI for the IAB parent body, and is interpreted to represent a body-wide melting event. Later, between 10 and 14 Ma after CAI, an impact led to a catastrophic break-up and subsequent reassembly of the parent body. Thermal models of the interior evolution that are consistent with these estimates suggest that the IAB parent body underwent metal\u2013silicate separation as a result of internal heating by short-lived radionuclides and accreted at around 1.4\u00b10.11.4\u00b10.1 Ma after CAIs with a radius of greater than 60 km.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Alison C. Hunt, David L. Cook, Tim Lichtenberg, Philip M. Reger, Mattias Ek, Gregor J. Golabek, Maria Sch\u00f6nb\u00e4chler Earth and Planetary Science Letters Volume 482, 15 January 2018, Pages 490\u2013500 LINK (OPEN ACCESS) PDF (OPEN&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[78,77,371,214,420],"tags":[852,1950,1881,1874,421,1206,4294,370,3292],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/13940"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=13940"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/13940\/revisions"}],"predecessor-version":[{"id":14374,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/13940\/revisions\/14374"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=13940"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=13940"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=13940"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}