Compositional fields for spinels from a wide variety of mafic– a wide range of conditions from mafic and ultramafic ultramafic igneous rock types and tectonic environments have been magmas and, in the case of chromites, are often among determined from a global database of over 26 000 analyses. the first phases to crystallize. They also exhibit a wide These fields are defined using contoured dat...

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...

Ultramafic and carbonate-rich rocks juxtaposed in an oceanic sedimentary mélange that experienced Alpine subduction (Champorcher, Aosta Valley, Italy) show evidence of metasomatic alteration at their contacts. The reactions occurred these contacts afford assessment the sources compositions fluids associated with alteration, degree scale which mobilized carbon. At contacts, display calcite repla...

A comprehensive study of a 340 m thick lenticular-sheet body ultramafic composition penetrated by structural well M-1 at depth about 2.2 km was accomplished. Its main volume is composed plagioharzburgite; fine-grained rocks norite and orthopyroxenite chilling zones are preserved on endocontacts. The the similar in to near underlying ore-bearing layered intrusion – Monchepluton. age 2510 ± 9 Ma ...