{"id":39609,"date":"2025-11-12T06:50:37","date_gmt":"2025-11-12T05:50:37","guid":{"rendered":"https:\/\/karmaka.de\/?p=39609"},"modified":"2025-11-12T06:50:38","modified_gmt":"2025-11-12T05:50:38","slug":"remanent-crustal-strain-on-mars-in-non-poikilitic-olivine-of-nwa-7721","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=39609","title":{"rendered":"Remanent crustal strain on Mars in non-poikilitic olivine of NWA 7721<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Yaozhu Li, Szilvia Kal\u00e1cska, Phil McCausland, Roberta L. Flemming, Callum Hetherington, Bo Zhao, Can Yildirim, Carsten Detlefs<\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/pdf\/2511.08316\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;We present a multiscale microstructural analysis of olivine from the non-poikilitic lithology of the poikilitic shergottite NWA 7721, using dark-field X-ray microscopy (DFXM), electron backscatter diffraction (EBSD), and context in situ 2D micro-XRD. A single olivine crystal contains two distinct subgrain populations. Type 1 subgrains are fine (1-5 micrometers), randomly oriented, and nearly strain-free, whereas Type 2 subgrains are coarse (greater than 30 micrometers), aligned, and strongly strained. Layered DFXM data reveal slip-band features in Type 2 that are absent in Type 1. We interpret Type 1 as products of shock-induced recrystallization, whereas Type 2 preserves remnants of a highly deformed parent grain. This bimodal microstructure, not observed in other Martian meteorites including the paired NWA 1950 and ALH A77005, points to a heterogeneous response to impact influenced by pre-existing strain in the olivine grain. We propose that NWA 7721 olivine experienced substantial crustal or magmatic stress before impact. The subsequent shock wave imposed a rapid load-release cycle that mobilized dislocations and produced low-angle boundaries in Type 2, while driving recrystallization of Type 1. Grain-growth constraints limit the post-shock heating duration to approximately 2.3 s, consistent with rapid quenching. These results provide the first evidence that non-poikilitic olivine in NWA 7721 preserves dynamic crustal deformation on Mars in the Late Amazonian.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Yaozhu Li, Szilvia Kal\u00e1cska, Phil McCausland, Roberta L. Flemming, Callum Hetherington, Bo Zhao, Can Yildirim, Carsten Detlefs PDF (OPEN ACCESS) &#8220;We present a multiscale microstructural analysis of olivine from the non-poikilitic lithology of the poikilitic&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[122,43],"tags":[6640,5578,1858,1006,4174,7009,292,4893,1829],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/39609"}],"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=39609"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/39609\/revisions"}],"predecessor-version":[{"id":39610,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/39609\/revisions\/39610"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=39609"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=39609"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=39609"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}