{"id":20556,"date":"2019-10-14T17:04:26","date_gmt":"2019-10-14T15:04:26","guid":{"rendered":"http:\/\/karmaka.de\/?p=20556"},"modified":"2019-10-14T17:04:32","modified_gmt":"2019-10-14T15:04:32","slug":"shock%e2%80%90thermal-history-of-the-agoudal-iiab-iron-meteorite-from-microstructural-studies","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=20556","title":{"rendered":"Shock\u2010thermal history of the Agoudal (IIAB) iron meteorite from microstructural studies"},"content":{"rendered":"\n<p>D. Ray, S. Ghosh, H. Chennaoui Aoudjehane, S. Das<\/p>\n\n\n\n<p>Meteoritics &amp; Planetary Science <br>\nFirst Published:  14 October 2019<\/p>\n\n\n\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/full\/10.1111\/maps.13399\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;The Agoudal IIAB iron meteorite exhibits only kamacite grains (~6 mm across) without any taenite. The kamacite is homogeneously enriched with numerous rhabdite inclusions of different size, shape, and composition. In some kamacite domains, this appears frosty due to micron\u2010scale rhabdite inclusions (~5 to 100 \u03bcm) of moderate to high Ni content (~26 to 40 wt%). In addition, all the kamacite grains in matrix are marked with a prominent linear crack formed during an atmospheric break\u2010up event and subsequently oxidized. This feature, also defined by trails of lowest Ni\u2010bearing (mean Ni: 23 wt%) mm\u2010scale rhabdite plates (fractured and oxidized) could be a trace of a pre\u2010existing \u03b3\u2013\u03b1 interface. Agoudal experienced a very slow rate of primary cooling ~4 \u00b0C Ma\u22121 estimated from the binary plots of true rhabdite width against corresponding Ni wt% and the computed cooling rate curves after Randich and Goldstein (1978). Chemically, Agoudal iron (Ga: 54 ppm; Ge: 140 ppm; Ir: 0.03 ppm) resembles the Ainsworth iron, the coarsest octahedrite of the IIAB group. Agoudal contains multiple sets of Neumann bands that are formed in space and time at different scales and densities due to multiple impacts with shock magnitude up to 130 kb. Signatures of recrystallization due to postshock low temperature mild reheating at about 400 \u00b0C are also locally present.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>D. Ray, S. Ghosh, H. Chennaoui Aoudjehane, S. Das Meteoritics &amp; Planetary Science First Published: 14 October 2019 LINK &#8220;The Agoudal IIAB iron meteorite exhibits only kamacite grains (~6 mm across) without any taenite. The&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[689,214],"tags":[832,1676],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20556"}],"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=20556"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20556\/revisions"}],"predecessor-version":[{"id":20557,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20556\/revisions\/20557"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20556"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20556"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20556"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}