Evolution of the upper mantle beneath the southern Baikal rift zone: an Sr-Nd isotope study of xenoliths from the Bartoy volcanoes

Petrology, Mineral and Isotope Geochemistry of the External Liguride Peridotites (Northern Apennines, Italy)

“…Much of the subcontinental lithospheric mantle may therefore be similar to the MORB-type mantle, because it is derived by accretion of asthenospheric mantle to the lithosphere, and this lithosphere did not suffer, during geologic times, any significant metasomatic or melt infiltration process. This interpretation has been inferred for various subcontinental sp lherzolite xenoliths Ionov et al, 1992;and Nd of 0-23-0-25, consistent with a typical depleted mantle (DM) source. Consequently, they do not contain age information about how long they have been incorporated in the lithosphere.…”

“…They show slight LREE depletion (Cejv-/Sm A r= 0-5-0-6) and almost flat M-to HREE patterns at 16-22 times Cl. Comparable REE abundances have been documented for kaersutite-Ti-pargasite amphiboles in the Zabargad sp lherzolites and in sp lherzolite xenoliths from the Baikal rift zone (Ionov et al, 1992) and the Arabian side of the Red Sea (Henjes- Kunst et al, 1990). REE patterns of sp-facies amphiboles are generally similar to the respective clinopyroxene patterns.…”

“…Amphibole formation without concomitant introduction of LREE and Sr has also been documented for spinel lherzolites from the Red Sea (Zabargad peridotites; Piccardo et al, 1993;Western Arabian xenoliths;Henjes-Kunst et al, 1990) and spinel lherzolite xenoliths from the Bartoy volcanoes of Siberia (Ionov et al, 1992). According to these workers, the above features suggest that the metasomatic agent from which amphibole crystallized was not enriched in incompatible elements, thus excluding alkaline melts or related high-density fluids.…”

Widespread refertilization of cratonic and circum-cratonic lithospheric mantle

“…9. (Press et al, 1986;Ionov et al, 1992bIonov et al, , 1993aIonov et al, , 1994Ionov et al, , 1995aIonov et al, , 2006aHofmann, 1995, 2007;Pearson et al, 1995b); Australian peridotites (Yaxley et al, 1991;McBride et al, 1996;Handler et al, 1997Handler et al, , 2005; European peridotites (Paul, 1971;Becker, 1996;Meisel et al, 1997;Zangana et al, 1999;Becker et al, 2001;Downes et al, 2002;Bodinier et al, 2004;Bianchini et al, 2007;Tessalina et al, 2007;Ackerman et al, 2009;Mazzucchelli et al, 2009); American peridotites (Carlson and Irving, 1994;Schmidberger and Francis, 1999;Schmidberger et al, 2001;Schilling et al, 2005;Ntaflos et al, 2007;Rivalenti et al, 2007;Bjerg et al, 2009); African peridotites (Rudnick et al, 1993;Pearson et al, 1995a;Simon et al, 2007;Wittig et al, 2010a). Other data sources are the same as in Fig.…”

Equilibrium interface segregation in the diopside–forsterite system II: Applications of interface enrichment to mantle geochemistry

“…1). Such discrepancies require storage of significant amounts of incompatible elements in cryptic phases such as accessory minerals, glass, fluid inclusions, or interfaces (e.g., Menzies and Murthy, 1978;Ottonello, 1980;Stosch et al, 1986;Zindler and Jagoutz, 1988;Ionov et al, 1992;Garrido et al, 2000;Xu et al, 2003). In some cases the discrepancy between whole rock and clean rock concentrations has been shown to increase with increasing incompatibility (Zindler and Jagoutz, 1988;Xu et al, 2003), an observation consistent with storage of these elements at interfaces.…”