{"id":14678,"date":"2018-04-24T07:56:15","date_gmt":"2018-04-24T05:56:15","guid":{"rendered":"http:\/\/karmaka.de\/?p=14678"},"modified":"2018-04-24T08:49:25","modified_gmt":"2018-04-24T06:49:25","slug":"ambient-and-cold%e2%80%90temperature-infrared-spectra-and-xrd-patterns-of-ammoniated-phyllosilicates-and-carbonaceous-chondrite-meteorites-relevant-to-ceres-and-other-solar-system-bodies","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=14678","title":{"rendered":"Ambient and cold\u2010temperature infrared spectra and XRD patterns of ammoniated phyllosilicates and carbonaceous chondrite meteorites relevant to Ceres and other solar system bodies<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"<p>Bethany L. Ehlmann, Robert Hodyss, Thomas F. Bristow, George R. Rossman, Eleonora Ammannito, M. Cristina De Sanctis, Carol A. Raymond<\/p>\n<p>Meteorit Planet Sci. . doi:10.1111\/maps.13103<\/p>\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/full\/10.1111\/maps.13103\" target=\"_blank\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br \/>\n<a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/maps.13103\" target=\"_blank\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n<p>&#8220;Mg\u2010phyllosilicate\u2010bearing, dark surface materials on the dwarf planet Ceres have NH4\u2010bearing materials, indicated by a distinctive 3.06 \u03bcm absorption feature. To constrain the identity of the Ceres NH4\u2010carrier phase(s), we ammoniated ground particulates of candidate materials to compare their spectral properties to infrared data acquired by Dawn&#8217;s Visible and Infrared (VIR) imaging spectrometer. We treated Mg\u2010, Fe\u2010, and Al\u2010smectite clay minerals; Mg\u2010serpentines; Mg\u2010chlorite; and a suite of carbonaceous meteorites with NH4\u2010acetate to exchange ammonium. Serpentines and chlorites showed no evidence for ammoniation, as expected due to their lack of exchangeable interlayer sites. Most smectites showed evidence for ammoniation by incorporation of NH4+ into their interlayers, resulting in the appearance of absorptions from 3.02 to 3.08 \u03bcm. Meteorite samples tested had weak absorptions between 3.0 and 3.1 \u03bcm but showed little clear evidence for enhancement upon ammoniation, likely due to the high proportion of serpentine and other minerals relative to expandable smectite phases or to NH4+ complexing with organics or other constituents. The wavelength position of the smectite NH4 absorption showed no variation between IR spectra acquired under dry\u2010air purge at 25 \u00b0C and under vacuum at 25 \u00b0C to \u2212180 \u00b0C. Collectively, data from the smectite samples show that the precise center wavelength of the characteristic ~3.05 \u03bcm v3 absorption in NH4 is variable and is likely related to the degree of hydrogen bonding of NH4\u2010H2O complexes. Comparison with Dawn VIR spectra indicates that the hypothesis of Mg\u2010saponite as the ammonium carrier phase is the simplest explanation for observed data, and that Ceres dark materials may be like Cold Bokkeveld or Tagish Lake but with proportionally more Mg\u2010smectite. &#8220;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Bethany L. Ehlmann, Robert Hodyss, Thomas F. Bristow, George R. Rossman, Eleonora Ammannito, M. Cristina De Sanctis, Carol A. Raymond Meteorit Planet Sci. . doi:10.1111\/maps.13103 LINK (OPEN ACCESS) PDF (OPEN ACCESS) &#8220;Mg\u2010phyllosilicate\u2010bearing, dark surface materials&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,167,10,18,335],"tags":[3273,1868,1054,4492,1758,473,4491,110,463,2693],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/14678"}],"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=14678"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/14678\/revisions"}],"predecessor-version":[{"id":14679,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/14678\/revisions\/14679"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14678"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14678"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14678"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}