{"id":18460,"date":"2019-04-23T09:59:04","date_gmt":"2019-04-23T07:59:04","guid":{"rendered":"http:\/\/karmaka.de\/?p=18460"},"modified":"2019-04-23T09:59:06","modified_gmt":"2019-04-23T07:59:06","slug":"3-micron-reflectance-spectroscopy-of-carbonaceous-chondrites-under-asteroid-like-conditions","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=18460","title":{"rendered":"3-micron Reflectance Spectroscopy of Carbonaceous Chondrites under Asteroid-like Conditions<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Driss Takir, Karen R. Stockstill-Cahill, Charles A. Hibbitts, Yusuke Nakauchi<\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/ftp\/arxiv\/papers\/1904\/1904.09453.pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;We  measured 3-\u03bcm  reflectance  spectraof  21  meteorites  that  represent  all carbonaceous chondrite types available in terrestrial meteorite collections. The measurements were conducted at the Laboratory for Spectroscopy under Planetary Environmental Conditions (LabSPEC) at the Johns Hopkins University Applied Physics Laboratory (JHU APL) under vacuum  and  thermally-desiccated  conditions (asteroid-like  conditions). This  is  the  most comprehensive3-\u03bcm dataset of carbonaceous chondrites ever acquired in environments similar to the ones experienced by asteroids. The 3-\u03bcm reflectance spectra are extremely important for direct comparisons with and appropriate interpretations of reflectance data from ground-based telescopic and spacecraft observations of asteroids. Wefoundgoodagreement between3-\u03bcmspectral characteristicsof carbonaceous chondrites and carbonaceous chondrite classifications. The 3-\u03bcm  bandis diverse, indicative  of  varying  composition,  thus suggesting that  these carbonaceous  chondrites experienced  distinct  parent  body aqueous  alteration  and metamorphism environments. The spectra of CI chondrites, from which significant amount of water adsorbed under ambient conditions was removed, are consistent with Mg-serpentine and clay minerals.The high abundances of organics in CI chondrites is also associated with the mineralogy  of  these  chondrites,  oxyhydroxides- and  complex  clay  minerals-rich. CM chondrites,  which  are  cronstedtite-rich, have shallower 3-\u03bcm  band  than  CI  chondrites, suggesting they experienced less aqueous alteration. CR chondrites showed moderate aqueous alteration relative to CI and CM chondrites. CV chondrites, except for Efremovka, have a very shallow 3-\u03bcm band, consistent with their lower phyllosilicate proportions. CO chondrites, like most  CVs, have  a  very  shallow  3-\u03bcm band that  suggest  they  experienced  minor  aqueous alteration. The 3-\u03bcm band in CH\/CBb is deep and broad centered ~ 3.11 \u03bcm, possibly due to the high abundance of FeNi metal and presence of heavily hydrated clasts in these chondrites. The3-\u03bcm spectra of Essebi (C2-ung) and EET 83226 are more consistent with CM chondrites\u2019 spectra. The 3-\u03bcm spectra of Tagish lake (C2-ung), on the other hand, are consistent with CI chondrites. None  of  these  spectral  details  could  have  been  resolved  without  removing  the adsorbed water before acquiring spectra.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Driss Takir, Karen R. Stockstill-Cahill, Charles A. Hibbitts, Yusuke Nakauchi PDF (OPEN ACCESS) &#8220;We measured 3-\u03bcm reflectance spectraof 21 meteorites that represent all carbonaceous chondrite types available in terrestrial meteorite collections. The measurements were conducted&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,584,583,10,15,18,19,12,14,335],"tags":[4957,1051,733,108,1594,4958,3273,1426,1887,1809,1124,105,1814,1810,4961,1812,4962,4959,687,567,3795,794,4960,630,107,473,4395,110,1479,997,463,482,4963],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/18460"}],"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=18460"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/18460\/revisions"}],"predecessor-version":[{"id":18461,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/18460\/revisions\/18461"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=18460"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=18460"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=18460"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}