LINK<\/strong><\/a><\/p>\n\n\n\n“Northwest Africa (NWA) 14672, the most highly shocked Martian meteorite so far, has experienced >50% melting, compatible with peak pressure >~65 Gpa, at a transition stage 6\/7. Despite these extreme shock conditions, the meteorite still preserves a population of \u201clarge\u201d Fe sulfide blebs from the pre-shock igneous assemblage. These primary blebs preserve characteristics of basaltic shergottites in term of modal abundance, preferential occurrence in interstitial pores along with late-crystallized phases (ilmenite, merrillite), and Ni-free pyrrhotite compositions. Primary sulfides underwent widespread shock-induced remelting, as indicated by perfect spherical morphologies when embedded in fine-grained silicate melt zones and a wealth of mineral\/glass\/vesicle inclusions. Extensive melting of Fe-sulfides is consistent with the decompression path experienced by NWA 14672 after the peak shock pressure at ~70\u2009GPa. Primary sulfides acted as preferential sites for nucleation of vesicles of all sizes which helped sulfur degassing during decompression, leading to partial resorption of Fe-sulfide blebs and reequilibration of pyrrhotite metal\/sulfur ratios (0.96\u20130.98) toward the low oxygen fugacity conditions indicated by Fe-Ti oxides hosted in fine-grained materials. The extreme shock intensity also provided suitable conditions for widespread in situ redistribution of igneous sulfur as micrometric globules concentrated in glassy portions of fine-grained lithologies. These globules exsolved early on quenching, allowing dendritic skeletal Fe-Ti oxide overgrowths to nucleate on sulfides.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Jean-Pierre Lorand, Sylvain Pont, Roger H. Hewins, Brigitte Zanda MAPS, Version of Record online: 04 July 2024 LINK “Northwest Africa (NWA) 14672, the most highly shocked Martian meteorite so far, has experienced >50% melting, compatible…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43,63],"tags":[1858,6529,1829,1844,6094],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/36408"}],"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=36408"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/36408\/revisions"}],"predecessor-version":[{"id":36409,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/36408\/revisions\/36409"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=36408"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=36408"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=36408"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}