LINK<\/strong><\/a><\/p>\n\n\n\n“We report the discovery of a unique, refractory phase\u2010bearing micrometeorite (WF1202A\u2010001) from the S\u00f8r Rondane Mountains, East Antarctica. A silicate\u2010rich cosmic spherule (~400 \u00b5m) displays a microporphyritic texture containing Ca\u2010Al\u2010rich inclusion (CAI)\u2010derived material (~5\u201310 area%), including high\u2010Mg forsterite (Fo98\u201099) and enstatite (En98\u201099, Wo0\u20101). The micrometeorite also hosts a spherical inclusion (~209 \u00b5m), reminiscent of chondrules, displaying a barred olivine texture. Oxygen isotopic compositions of the micrometeorite groundmass (\u03b417O = \u20133.46\u2030, \u03b418O = 10.43\u2030, \u220617O = \u20131.96\u2030) are consistent with a carbonaceous chondrite precursor body. Yet, a relict forsterite grain is characterized by \u03b417O = \u201345.8\u2030, \u03b418O = \u201343.7\u2030, \u220617O = \u201323.1\u2030, compatible with CAIs. In contrast, a relict low\u2010Ca pyroxene grain (\u03b417O = \u20134.96\u2030, \u03b418O = \u20134.32\u2030, \u220617O = \u20132.71\u2030) presumably represents a first\u2010generation silicate grain that accreted 18O\u2010rich gas or dust in a transient melting scenario. The spherical inclusion displays anomalous oxygen isotope ratios (\u03b417O = \u20130.98\u2030, \u03b418O = \u20132.16\u2030, \u220617O = 0.15\u2030), comparable to anhydrous interplanetary dust particles (IDPs) and fragments from Comet 81P\/Wild2. Based on its major element geochemistry, the chondrule size, and oxygen isotope systematics, micrometeorite WF1202A\u2010001 likely sampled a carbonaceous chondrite parent body similar to, but distinct from CM, CO, or CV chondrites. This observation may suggest that some carbonaceous chondrite bodies can be linked to comets. The reconstructed atmospheric entry parameters of micrometeorite WF1202A\u2010001 suggest that the precursor particle originated from a low\u2010inclination, low\u2010eccentricity source region, most likely either the main belt asteroids or Jupiter family comets (JFCs).”<\/p>\n","protected":false},"excerpt":{"rendered":"
Bastien Soens, Martin D. Suttle, Ryoga Maeda, Frank Vanhaecke, Akira Yamaguchi, Matthias Van Ginneken, Vinciane Debaille, Philippe Claeys, Steven Goderis Meteoritics & Planetary ScienceVersion of Record online: 24 November 2020 LINK “We report the discovery…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,179,3157,127],"tags":[1846,1937,3275,1381,301,5132,327],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/25372"}],"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=25372"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/25372\/revisions"}],"predecessor-version":[{"id":25373,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/25372\/revisions\/25373"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=25372"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25372"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25372"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}