{"id":21454,"date":"2020-02-12T21:57:44","date_gmt":"2020-02-12T20:57:44","guid":{"rendered":"http:\/\/karmaka.de\/?p=21454"},"modified":"2020-02-12T21:57:45","modified_gmt":"2020-02-12T20:57:45","slug":"a-compositionally-heterogeneous-martian-mantle-due-to-late-accretion","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=21454","title":{"rendered":"A compositionally heterogeneous martian mantle due to late accretion<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Simone Marchi, Richard J. Walker and Robin M. Canup<\/p>\n\n\n\n<p>Science Advances  12 Feb 2020:<br>\nVol. 6, no. 7, eaay2338<br>\nDOI: 10.1126\/sciadv.aay2338<\/p>\n\n\n\n<p><a href=\"https:\/\/advances.sciencemag.org\/content\/6\/7\/eaay2338\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br>\n<a href=\"https:\/\/advances.sciencemag.org\/content\/advances\/6\/7\/eaay2338.full.pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;The approximately chondritic estimated relative abundances of highly siderophile elements (HSE) in the bulk martian mantle suggest that these elements were added after Mars\u2019 core formed. The shergottite-nakhlite-chassigny (SNC) meteorites imply an average mantle Pt abundance of \u22483 to 5 parts per billion, which requires the addition of 1.6 \u00d7 1021 kilograms of chondritic material, or 0.25% martian masses, to the silicate Mars. Here, we present smoothed particle hydro-dynamics impact simulations that show that Mars\u2019 HSE abundances imply one to three late collisions by large differentiated projectiles. We show that these collisions would produce a compositionally heterogeneous martian mantle. Based mainly on W isotopes, it has been argued that Mars grew rapidly in only about 2 to 4 million years (Ma). However, we find that impact generation of mantle domains with variably fractionated Hf\/W and diverse 182W could imply a Mars formation time scale up to 15 Ma.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Simone Marchi, Richard J. Walker and Robin M. Canup Science Advances 12 Feb 2020: Vol. 6, no. 7, eaay2338 DOI: 10.1126\/sciadv.aay2338 LINK (OPEN ACCESS) PDF (OPEN ACCESS) &#8220;The approximately chondritic estimated relative abundances of highly&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[45,122,42,44,43],"tags":[1831,1048,641,1858,1920,1830,1829],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21454"}],"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=21454"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21454\/revisions"}],"predecessor-version":[{"id":21455,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21454\/revisions\/21455"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21454"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21454"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21454"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}