LINK<\/strong><\/a><\/p>\n\n\n\n“Zak\u0142odzie is an enstatite meteorite of unknown petrogenesis. Chemically, it resembles enstatite chondrites, but displays an achondrite\u2010like texture. Here we report on fabric and texture analyses of Zak\u0142odzie utilizing X\u2010ray computed tomography and scanning electron microscopy and combine it with a nanostructural study of striated pyroxene by transmission electron microscopy. With this approach we identify mechanisms that led to formation of the texture and address the petrogenesis of the rock. Zak\u0142odzie experienced a shock event in its early evolution while located at some depth inside a warm parent body. Shock\u2010related strain inverted pyroxene to the observed mixture of intercalated orthorhombic and monoclinic polymorphs. The heat that dissipated after the peak shock was added to primary, radiogenic\u2010derived heat and led to a prolonged thermal event. This caused local, equilibrium\u2010based partial melting of plagioclase and metal\u2010sulfide. Partial melting was followed by two\u2010stage cooling. The first phase of annealing (above 500 \u00b0C) allowed for crystallization of plagioclase and for textural equilibration of metal and sulfides with silicates. Below 500 \u00b0C, cooling was faster and more heterogeneous at cm scale, allowing retention of keilite and quenching of K\u2010rich feldspathic glass in some parts. Our study indicates that Zak\u0142odzie is neither an impact melt rock nor a primitive achondrite, as suggested in former studies. An impact melt origin is excluded because enstatite in Zak\u0142odzie was never completely melted and partial melting occurred during equilibrium\u2010based postshock conditions. Texturally, the rock represents a transition of chondrite and achondrite and was formed when early impact heat was added to internal radiogenic heat.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Agata M. Krzesi\u0144ska, Richard Wirth, Monika A. Kusiak Meteoritics & Planetary Science First Published: 29 April 2019 LINK “Zak\u0142odzie is an enstatite meteorite of unknown petrogenesis. Chemically, it resembles enstatite chondrites, but displays an achondrite\u2010like…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28,17],"tags":[1819,1813,364,1820,988],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/19273"}],"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=19273"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/19273\/revisions"}],"predecessor-version":[{"id":19274,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/19273\/revisions\/19274"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19273"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19273"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19273"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}