introduction mineral composition is sensitive to variations in the composition of the magma and can be used to characterize the physical conditions of crystallization such as temperature, pressure, oxygen fugacity and water content. the studies have demonstrated that geobarometery by amphibole provides a tool for determining the depth of crystallization and knowledge of the depth of crystalliza...

Ž . Gabbroic sills intruding dunite in the crust–mantle transition zone MTZ of the Oman ophiolite have textures and compositions very similar to those in modally layered gabbros that form the lower part of the gabbro section in the ophiolite, and different from those in non-layered gabbros near the dike–gabbro transition. The presence of gabbroic sills in the MTZ indicates that modally layered ...

Located in the southern margin of Central Asian orogenic belt, stratigraphy and tectonic setting mafic 290−280 Ma Liuyuan Complex have been controversial for decades, with workers arguing a forearc ophiolite or continental rift setting. Here, we present results detailed field study, where was subdivided into troctolite, melatroctolite, layered gabbro, varitextured olivine hornblende plagiograni...

the area under study is located 75 km north of isfahan north of fenshark village.the mesozoic deposits of this area have been metamorphosed in the vicinity of neogene granodiorites and quartzdiorites ,forming hornfelses in three individual facies albit-epidot-hornfelses in three individual facies albit-epidot-hornblende-and pyroxene hornfels. wollastonite,vesuvianite,garnet and calcite are the ...

[1] Abstract: Analysis of crystal size distributions (CSD) of plagioclase in gabbros from the Oman ophiolite indicates that cooling rates in the lower crust beneath a mediumto fast-spreading oceanic ridge did not vary smoothly with depth. Cooling rates in the upper half of the gabbro section were approximately 1.5–2 times faster than in the lower half of the gabbro section during igneous crysta...

the formation of atoll garnet in hornblende schists from the contact aureole of mashhad granite,ne iran, is discussed using textural and chemical data. these data suggest the possibility of incipientreplacement of pre-existing idioblastic garnet from the core. in addition, the presence of chlorite and calcite inthe core of atoll garnet reveal the retrograde nature of atoll formation.

some small gabbro patches emplaced along the thrust fault with w-e trend in the vicinity of maien bolagh village at the ht/mp metapelites, a part of the central iran zone (near to sanandaj-sirjan zone). the coarse-grained dark gabbro samples consist of amphibole, clinopyroxene, plagioclase, minor quartz, titanite, and biotite. gabbros have high potassic calc-alkaline to shoshonitic affinity. th...