A new collection of mantle xenoliths in Tertiary dykes from the Wiedemann Fjord area in Southeast Greenland shows that this part of the central Greenland craton is underlain by highly depleted peridotites. The samples are mostly spinel Ž . harzburgites with highly forsteritic olivines Fo , average Fo . This, together with unusually high modal olivine 87– 94 92.7 Ž . contents 70–)95% , places th...

Spinels from cumulus and non-cumulus members of the 0thris ophiolite display a considerable variation in composition. Cumulus pierites and gabbros contain either a primary chromite and/or a reaction spinel formed by reaction with co-existing sili?ate,-" (Cr--A1 varia tion) or intercumulus liquid (Cr--Fe variation). Non-cumulus peridotites contain spinels which vary along a Cr--A1 trend. Harzbur...

The selected peridotite samples come from the Josephine ophiolite, emplaced 157 My ago and now part of the western Jurassic belt of the Klamath Mountains in Northern California and Southwest Oregon [1]. The ophiolite is partly dismembered but presents a complete ophiolitic section from mantle peridotites in the lower part (our samples) to pillow lavas at the top. The Josephine peridotite extend...

Concentrations of the incompatible trace elements and REEs in the upper mantle rocks of the Northern Semail ophiolite are very low, as typical in the residua of partial melting and in the early products of a fractionating magma. However, their geochemical characteristics have shown indications of hydrous magmas that more likely related to a subduction environment. Melt extraction can play a cru...

The Kuhshah ultramafic complex is located in the south-east of Sanandaj-Sirjan metamorphic zone, near the probable remnants of Neotethys plate in Iran. It consists of highly depleted harzburgites, dunites, chromitite bands and altered gabbros. The ultramafic parts have been intruded by numerous clinopyroxenite dykes and veins. In the harzburgites, there are different generations of olivine, ort...

Differentiation of the Earth's mantle occurs principally through partial melting and extraction of basaltic melt. Among the mantle rocks occurring at the Earth's surface, harzburgites are widely considered as refractory mantle residues left after extraction of a basaltic component. In contrast, fertile lherzolites are generally regarded as pristine mantle, only weakly affected by partial meltin...

the kuhshah ultramafic complex is located in the south-east of sanandaj-sirjan metamorphic zone, near the probable remnants of neotethys plate in iran. it consists of highly depleted harzburgites, dunites, chromitite bands and altered gabbros. the ultramafic parts have been intruded by numerous clinopyroxenite dykes and veins. in the harzburgites, there are different generations of olivine, ort...

Peridotite xenoliths in arc volcanoes are very rare, usually small and remain poorly studied. Much of the earlier work focused on peridotites affected by re-crystallization, metasomatism and veining that took place shortly before the eruption of the host magmas; such lithologies may not be widespread in the mantle wedge.This study reports petrographic, major and trace element data for 17 large,...

The Spontang Ophiolite complex represents the most complete ophiolite sequence amongst South Ladakh ophiolites and comprises mantle rocks (depleted harzburgites, dunites minor lherzolites) as well crustal (basalt, isotropic gabbros, layered gabbros etc.). In present study, detailed geochemistry (whole rock mineral chemistry) Sr-Nd isotopic analyses of thirty-six ultramafic- mafic samples have b...