{"id":12278,"date":"2017-04-11T10:22:33","date_gmt":"2017-04-11T08:22:33","guid":{"rendered":"http:\/\/karmaka.de\/?p=12278"},"modified":"2017-04-11T11:00:33","modified_gmt":"2017-04-11T09:00:33","slug":"type-1-aqueous-alteration-in-cm-carbonaceous-chondrites-implications-for-the-evolution-of-water-rich-asteroids","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=12278","title":{"rendered":"Type 1 aqueous alteration in CM carbonaceous chondrites: Implications for the evolution of water-rich asteroids<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"<p>A.J. King, P.F. Schofield, S.S. Russell<\/p>\n<p>Meteoritics &#038; Planetary Science. doi: 10.1111\/maps.12872<\/p>\n<p><a href=\"http:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/maps.12872\/full\" target=\"_blank\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br \/>\n<a href=\"http:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/maps.12872\/epdf\" target=\"_blank\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n<p>&#8220;The CM carbonaceous chondrite meteorites experienced aqueous alteration in the early solar system. They range from mildly altered type 2 to almost completely hydrated type 1 chondrites, and offer a record of geochemical conditions on water-rich asteroids. We show that CM1 chondrites contain abundant (84\u201391 vol%) phyllosilicate, plus olivine (4\u20138 vol%), magnetite (2\u20133 vol%), Fe-sulfide (<5 vol%), and calcite (<2 vol%). The CM1\/2 chondrites contain phyllosilicate (71\u201388 vol%), olivine (4\u201320 vol%), enstatite (2\u20136 vol%), magnetite (2\u20133 vol%), Fe-sulfides (1\u20132 vol%), and calcite (~1 vol%). As aqueous alteration progressed, the abundance of Mg-serpentine and magnetite in the CM chondrites increased. In contrast, calcite abundances in the CM1\/2 and CM1 chondrites are often depleted relative to the CM2s. The modal data support the model, whereby metal and Fe-rich matrix were the first components to be altered on the CM parent body(ies), before further hydration attacked the coarser Mg-rich silicates found in chondrules and fragments. Based on the absence of tochilinite, we suggest that CM1 chondrites experienced increased alteration due to elevated temperatures (>120 \u00b0C), although higher water\/rock ratios may also have played a role. The modal data provide constraints for interpreting the composition of asteroids and the mineralogy of samples returned from these bodies. We predict that \u201cCM1-like\u201d asteroids, as has been proposed for Bennu\u2014target for the OSIRIS-REx mission\u2014will have a high abundance of Mg-rich phyllosilicates and Fe-oxides, but be depleted in calcite.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A.J. King, P.F. Schofield, S.S. Russell Meteoritics &#038; Planetary Science. doi: 10.1111\/maps.12872 LINK (OPEN ACCESS) PDF (OPEN ACCESS) &#8220;The CM carbonaceous chondrite meteorites experienced aqueous alteration in the early solar system. They range from mildly&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[61,9,59,18],"tags":[1842,3273,105,2224,2990,3783,3777,3781,3787,3786,3778,3779,3782,3785,3780,3784],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/12278"}],"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=12278"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/12278\/revisions"}],"predecessor-version":[{"id":12279,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/12278\/revisions\/12279"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12278"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12278"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12278"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}