LINK<\/strong><\/a><\/p>\n“Baszk\u00f3wka is an equilibrated, apparently low\u2010shock, unusually porous chondrite. Some earlier studies were undertaken to understand whether the porosity in Baszk\u00f3wka, and similar porous chondrites, is a relic of a primordial feature or rather the effect of atypical reprocessing on the parent body. Neither of the studies reconstructed the accurate thermal and deformational evolution of chondrites, however, while it is known that shock\u2010induced compaction is the main means to affect chondritic porosity. Here we use a combination of 3\u2010D and 2\u2010D petrographic examination to understand how the evolution of pores correlates with thermal and shock history recorded in the Baszk\u00f3wka chondrite. The grain framework silicates in Baszk\u00f3wka contain healed shock fractures\u2014a clear recorder of significant shock process and postshock annealing. Simultaneously, metal grains do not exhibit any preferred orientation or fabric, which would be expected to develop in response to the deformation as recorded by silicates. We interpret this as evidence for re\u2010agglomeration and annealing of shocked material. Pore spaces in Baszk\u00f3wka are connected and decorated by fine\u2010grained plagioclase\u2010dominated mass and bulky euhedral olivine crystals, which exhibit growth steps on crystal surfaces. The euhedral olivine must have formed owing to the condensation of a vapor, while plagioclase most likely crystallized from melted chondritic matrix. During the shock event, fine\u2010grained matrix in Baszk\u00f3wka was melted and vaporized. Vapor expansion added to ballistic velocity led to ejection and opening of the pore spaces. After re\u2010agglomeration in a hot ejecta blanket the rock was annealed, melted material circulated in created pore spaces and vapor condensed.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Agata M. Krzesi\u0144ska, Natasha V. Almeida Meteoritics & Planetary Science First published: 3 September 2018 LINK “Baszk\u00f3wka is an equilibrated, apparently low\u2010shock, unusually porous chondrite. Some earlier studies were undertaken to understand whether the porosity…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23,7],"tags":[4672,1815,4199,1807],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/16229"}],"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=16229"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/16229\/revisions"}],"predecessor-version":[{"id":16230,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/16229\/revisions\/16230"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=16229"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=16229"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=16229"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}