{"id":20306,"date":"2019-08-20T22:38:42","date_gmt":"2019-08-20T20:38:42","guid":{"rendered":"http:\/\/karmaka.de\/?p=20306"},"modified":"2019-08-22T18:25:05","modified_gmt":"2019-08-22T16:25:05","slug":"the-yamato-type-cy-carbonaceous-chondrite-group-analogues-for-the-surface-of-asteroid-ryugu","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=20306","title":{"rendered":"The Yamato-type (CY) carbonaceous chondrite group: Analogues for the surface of asteroid Ryugu?<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>A.J. King, H.C. Bates, D. Krietsch, H. Busemann, P.L. Clay, P.F. Schofield, S.S. Russell<\/p>\n\n\n\n<p>Geochemistry<br>\nAvailable online 20 August 2019<\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0009281919300236\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><\/p>\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0009281919300236\/pdfft?md5=5214a1412d199f764127a15d7da453e4&amp;pid=1-s2.0-S0009281919300236-main.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;We report new mineralogical, petrographic and noble gas analyses of the carbonaceous chondrite meteorites Y-82162 (C1\/2ung), Y-980115 (CI1), Y-86029 (CI1), Y-86720 (C2ung), Y-86789 (C2ung), and B-7904 (C2ung). Combining our results with literature data we show that these meteorites experienced varying degrees of aqueous alteration followed by short-lived thermal metamorphism at temperatures of &gt;500\u2009\u00b0C. These meteorites have similar mineralogy, textures and chemical characteristics suggesting that they are genetically related, and we strongly support the conclusion of Ikeda (1992) that they form a distinct group, the CYs (\u201cYamato-type\u201d). The CY chondrites have the heaviest oxygen isotopic compositions (\u03b417O \u02dc12 \u2030, \u03b418O \u02dc22 \u2030) of any meteorite group, high abundances of Fe-sulphides (\u02dc10 \u2012 30\u2009vol%) and phosphates, and contain large grains of periclase and unusual objects of secondary minerals not reported in other carbonaceous chondrites. These features cannot be attributed to parent body processes alone, and indicate that the CYs had a different starting mineralogy and\/or alteration history to other chondrite groups, perhaps because they formed in a different region of the protoplanetary disk. The short cosmic-ray exposure ages (\u22641.3 Ma) of the CY chondrites suggest that they are derived from a near-Earth source, with recent observations by the Hayabusa2 spacecraft highlighting a possible link to the rubble-pile asteroid Ryugu.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A.J. King, H.C. Bates, D. Krietsch, H. Busemann, P.L. Clay, P.F. Schofield, S.S. Russell Geochemistry Available online 20 August 2019 LINK (OPEN ACCESS) PDF (OPEN ACCESS) &#8220;We report new mineralogical, petrographic and noble gas analyses&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[61,9,10,5044,2243,16,62,335],"tags":[3872,1842,3993,3273,1809,4823,4824,4821,5145,4825,2244,882,1843,729,731,340,4822,341],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20306"}],"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=20306"}],"version-history":[{"count":5,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20306\/revisions"}],"predecessor-version":[{"id":20311,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20306\/revisions\/20311"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20306"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20306"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20306"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}