In advance of the arrival of the DAWN spacecraft at 4Vesta in 2011, it is useful to reassess our knowledge of the constitution and probable evolution of this ancient differentiated asteroid. It has been recognized for some time that the eucrite, diogenite and howardite meteorites likely represent samples from 4Vesta or from related Vestoids based upon the good match of reflectance spectra of th...

Peridotites of Ulten Zone (Eastern Alps, N Italy) show a transition from coarse protogranular spinel lherzolites to fine-grained amphibole + garnet peridotites, recorded by the crystallization coronas around spinel. Pyroxenite veins, transposed along peridotite foliation, similar metamorphic evolution coarse-grained (garnet-free) websterites websterites. In both peridotites and websterites, pre...

The Neoproterozoic shoshonitic and mildly alkaline bimodal volcanism of Southernmost Brazil is represented by rock assemblages associated to sedimentary successions, deposited in strike-slip basins formed at the post-collisional stages of the Brasilian/Pan-African orogenic cycle. The best-preserved volcano sedimentary associations occur in the Camaquã and Campo Alegre Basins, respectively in th...

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...

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...

One characteristic of many subduction zone garnet peridotites is that they contain titanium-bearing phases not otherwise Ž . found in mantle rocks. In particular, titanoclinohumite TiCH andror its breakdown assemblage consisting of symplectic intergrowths of olivine and ilmenite is common in many of these bodies. The Alpe Arami garnet lherzolite of the Lepontine Alps, while lacking TiCH, displa...

We investigated calcite veins in two spinel-garnet peridotite xenoliths from the sub-Sierra Nevada mantle. These peridotites represent samples of the lithospheric mantle wedge beneath the Mesozoic California magmatic arc, as indicated by radiogenic isotopic ratios measured on clinopyroxenes separates (Sr/Sr8 Ma= 0.7058-0.7061, Nd/Nd8 Ma= 0.512538-0.512601). Mineral chemistry of the peridotite m...

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...

Trace element analyses (first-series transition elements, Ti, Rb, Sr, Zr, Y, Nb, and REE) were carried out on whole rocks and minerals from 10 peridotite samples from both Conical Seamount in the Mariana forearc and Torishima Forearc Seamount in the Izu-Bonin forearc using a combination of XRF, ID-MS, ICP-MS, and ion microprobe. The concentrations of incompatible trace elements are generally lo...