LINK<\/strong><\/a><\/p>\n“Highlights
\n\u2022 Beni M’hira belongs to Ordovician impact event, 4He gas retention age is 485 Ma.
\n\u2022 Cosmic ray exposure age of Beni M’hira is 15.6 Ma.
\n\u2022 Trapped noble gas composition (Ar, Kr, Xe) is Q type.
\n\u2022 Nitrogen isotopic composition in Beni M’hira is 14.6\u2030.”<\/p>\n
“The concentrations and isotopic composition of noble gases helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon(Xe) and nitrogen were measured in the Beni M’hira L6 chondrite. The cosmic ray exposure age of Beni M’hira is estimated of 15.6\u202f\u00b1\u202f3.7 (Ma). The radiogenic age, of around 485\u202f\u00b1\u202f64 Ma, derived from 4He, and of around 504\u202f\u00b1\u202f51 Ma from 40Ar, suggests an age resetting indicating the event impact. The heavy noble gases (Ar, Kr and Xe) concentrations imply that the gas is a mixture of trapped component Q and solar wind. The measured nitrogen abundance of 0.74\u202fppm and the isotopic signature of \u03b415N\u202f=\u202f14.6\u2030 are within the range of ordinary chondrites. The homogeneous chemical composition of olivine (Fa:26\u202f\u00b1\u202f0.25) and low-Ca pyroxene (Fs:22.4\u202f\u00b1\u202f0.29) suggest that the Beni M’hira meteorite is an equilibrated chondrite. This is further corroborated by strong chondrule-matrix textural integration (lack of chondrules, except a few relict clast). Shock metamorphism generally corresponds to S5 (>45\u202fGPa), however, locally disequilibrium melting (shock-melt veins) suggests, that the peak shock metamorphism was at \u223c75\u202fGPa, 950\u202f\u00b0C.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Ramakant R. Mahajan, Laridhi Ouazaa Nejia, Dwijesh Ray, Sekhar Naik Planetary and Space Science In Press, Accepted Manuscript, Available online 3 January 2018 LINK “Highlights \u2022 Beni M’hira belongs to Ordovician impact event, 4He gas…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[69,506],"tags":[4345,1849,1815,225,1807],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/14079"}],"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=14079"}],"version-history":[{"count":3,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/14079\/revisions"}],"predecessor-version":[{"id":14082,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/14079\/revisions\/14082"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14079"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14079"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14079"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}