par Ionov, Dimitri ;Doucet, Luc Serge ;Carlson, Richard Walter;Golovin, Alexander;Korsakov, Andrey A.V.
Référence Geochimica et cosmochimica acta, 165, page (466-483)
Publication Publié, 2015-09
Référence Geochimica et cosmochimica acta, 165, page (466-483)
Publication Publié, 2015-09
Article révisé par les pairs
Résumé : | The formation age of the Siberian cratonic mantle is not well established. Re-Os data on various mantle-derived materials brought up by kimberlite magmas have shown that it contains Archean components, but the reported ages range broadly (3.4 to <1Ga). We report Re-Os isotope and PGE concentration data for a suite of 29 fresh, well-characterized xenoliths from the Udachnaya-East kimberlite representing all major peridotite rock types and a large part of the cratonic mantle profile. Several xenoliths with very low Os contents (<0.3 ppb) and/or high Re/Os ratios are not suitable for age estimates. The Os (and Ir) depletions are common in cpx-bearing spinel harzburgites and coarse garnet harzburgites, but are not found in deformed, high-T peridotites. Twenty refractory (Al |