Beschreibung:
<jats:p><jats:bold>Abstract—</jats:bold> Cañon Diablo meteoritic iron oxide consists mainly of goethite and maghemite and contains 209 to 630 ppb uranium compared to <0.02 ppb in the unweathered octahedrite. Significant radioactive disequilibria between <jats:sup>238</jats:sup>U, <jats:sup>234</jats:sup>U and <jats:sup>230</jats:sup>Th indicate that uranium was sorbed from soil porewater during terrestrial weathering after meteorite impact 50 ka ago. Depending on the model assumed for U uptake, corrected <jats:sup>230</jats:sup>Th‐<jats:sup>234</jats:sup>U ages of 24 to 48 ka were obtained. While the data presented may not allow an unambiguous interpretation, the potential of this approach in obtaining minimum terrestrial ages for weathered meteorites is demonstrated.</jats:p>