LINK<\/strong><\/a><\/p>\n\n\n\n“Winonaites are a group of primitive achondrites with broadly chondritic bulk compositions and relict chondritic textures that reflect variable and limited extents of partial melting due to incomplete parent-body metal-silicate segregation. Winonaites therefore provide a snapshot of the role of incipient heating and melting in chondritic parent bodies. Among different winonaite samples, a high degree of inherent textural and chemical heterogeneities on small scales (<1 cm) is observed, likely resulting from variations in heating, metamorphism, impact brecciation, and reassembly. To investigate parent-body heterogeneities and early metal-silicate differentiation, we present whole-rock highly siderophile element (HSE; including Re, Os, Ir, Ru, Pt, Pd) abundances and 187Re-187Os data for seven winonaites. We also report HSE abundances (Re, Os, Ir, Ru, Rh, Pt, Pd, Au) for winonaite metal and sulfides measured in situ. Bulk-rock winonaites all have broadly chondritic measured 187Os\/188Os (0.1267\u202f\u00b1\u202f0.0010, 2SE). Among the bulk winonaites analyzed, Winona and Tierra Blanca show the greatest degrees of inter-element HSE fractionation. By contrast, Graves Nunataks 12510, Yamato-8005, and Pontlyfni have near-chondritic bulk major- and trace-elements abundances, and relative HSE abundance patterns. Unlike other primitive achondrite groups, supra-chondritic Pd\/Pt and Pd\/Os ratios are characteristic of winonaite metals, possibly suggesting a nebular or parent-body process (e.g., fractional fusion) origin. The HSE abundances of winonaite metals suggest compositional similarities with the IAB sLL iron meteorite subgroup and argue against a genetic connection with main group IAB irons, demonstrating the need for future nucleosynthetic and chronological studies to reevaluate the previously proposed winonaite-IAB connection.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Xinmu J. Zhang, James M.D. Day, Robert W. Nicklas, Yash Srivastava Geochimica et Cosmochimica Acta, In Press, Journal Pre-proof, Available online 7 November 2025 LINK “Winonaites are a group of primitive achondrites with broadly chondritic…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[371,214,29,32],"tags":[1049,411,6604,1048,1881,4417,3361,3900,3357,4941,1821,4942,7008],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/39522"}],"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=39522"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/39522\/revisions"}],"predecessor-version":[{"id":39523,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/39522\/revisions\/39523"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=39522"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=39522"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=39522"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}