Recent studies of serpentine-free, spinel peridotite xenoliths from the mantle lithosphere beneath active Kamchatka and West Bismarck arcs have shown that these rocks are enriched in silica highly depleted incompatible elements comparison with melting residues either primitive or mid-ocean ridge mantle. It has been suggested silica-rich nature peridotites intra-oceanic, fore- sub-arc lithospher...

Lithium elemental and isotopic compositions of olivines in peridotite xenoliths from Hebi in the North China Craton provide direct evidence for the highly variable δ(7)Li in Archean lithospheric mantle. The δ(7)Li in the cores of olivines from the Hebi high-Mg# peridotites (Fo > 91) show extreme variation from -27 to +21, in marked deviation from the δ(7)Li range of fresh MORB (+1.6 to +5.6) al...

The components of rock-forming and accessory minerals of the upper mantle, transition zone and lower mantle rocks have been involved into the processes of diamond genesis. Through their dissolving in primary carbonate melts, the mantle minerals have turned into components of the parental silicate-(±oxide)carbonate-carbon melts-solutions for diamonds and co-crystallized paragenetic minerals. The...

The components of rock-forming and accessory minerals of the upper mantle, transition zone and lower mantle rocks have been involved into the processes of diamond genesis. Through their dissolving in primary carbonate melts, the mantle minerals have turned into components of the parental silicate-(±oxide)carbonate-carbon melts-solutions for diamonds and co-crystallized paragenetic minerals. The...

Abstract Harzburgites and dunites forming the base of Late Cretaceous–Paleocene Papuan Ultramafic Belt (PUB) Marum ophiolites Papua New Guinea (PNG) are among most refractory mantle peridotites on Earth. We present a new integrated dataset major element, bulk plus mineral trace element Re–Os isotopic analyses aimed at better understanding genesis these peridotites. The PUB harzburgites contain ...

We investigated calcite globules and veins in two spinel-garnet peridotite xenoliths from the subSierra Nevada mantle. The studied xenoliths were entrained in a Miocene (11 Ma) volcanic plug. These carbonates are associated spatially with silicate glass inclusions, suggesting that they are primary inclusions—inclusions that formed at high temperature in the mantle and not at or close to the Ear...

The components of rock-forming and accessory minerals of the upper mantle, transition zone and lower mantle rocks have been involved into the processes of diamond genesis. Through their dissolving in primary carbonate melts, the mantle minerals have turned into components of the parental silicate-(±oxide)carbonate-carbon melts-solutions for diamonds and co-crystallized paragenetic minerals. The...

Abstract Devolatilization of subducting lithologies liberates COH-fluids. These may become partially sequestered in peridotites the slab and overlying forearc mantle, affecting cycling volatiles fluid mobile elements subduction zones. Here we assess magnitudes, timescales mechanism channelized injection COH-fluids doped with $${\mathrm{Ca}}_{\mathrm{aq}}^{2+}$$ <mml:math xmlns:mml="http://www.w...