Mineral chemistry and geothermobarometry of gabbroic rocks from the Gysel area, Alborz mountains, north Iran

The gabbroic rocks in the Gysel area of the Central Alborz Mountains in north Iran are intruded into the Eocene Volcano-sedimentary units. The main gabbroic rocks varieties include gabbro porphyry, olivine gabbro, olivine dolerite and olivine monzo-gabbro. The main minerals phases in the rocks are plagioclase and pyroxene and the chief textures are sub-hedral granular, trachytoidic, porphyritic, intergranular and poikilitic. Electron microprobe analyses on minerals in the rock samples shows that plagioclase composition ranges from labradorite to bytonite, with oscillatory and normal chemical zonings. Clinopyroxene is augite and orthopyroxene is hypersthene to ferro-hypersthene. Thermometry calculations indicate temperatures of 650˚C to 750˚C for plagioclase crystallization and 950˚C to 1130˚C for pyroxene crystallization. Clinopyroxene chemistry reveals sub-alkaline and calc-alkaline nature for the parental magma emplaced in a volcanic arc setting.

Supplemental Material: Sustainable densification of the deep crust

Materials and methods, Figures S1–S9 (fluid-inclusion mapping and point analyses of garnet and clinopyroxene with FTIR, sensitivity analyses for the two numerical models, results of the diffusion-reaction model in open system conditions, X-ray mapping of amphibole inclusions in clinopyroxene, evolution in space of the plagioclase composition), Tables S1 and S2 (chemical composition of the main minerals, and local bulk composition used for numerical modelling), and Movies S1 and S2 (results in 2-D of the model coupling reaction, fluid flow, and deformation).<br>

Supplemental Material: Sustainable densification of the deep crust

Materials and methods, Figures S1–S9 (fluid-inclusion mapping and point analyses of garnet and clinopyroxene with FTIR, sensitivity analyses for the two numerical models, results of the diffusion-reaction model in open system conditions, X-ray mapping of amphibole inclusions in clinopyroxene, evolution in space of the plagioclase composition), Tables S1 and S2 (chemical composition of the main minerals, and local bulk composition used for numerical modelling), and Movies S1 and S2 (results in 2-D of the model coupling reaction, fluid flow, and deformation).<br>

Mineralogical, Petrological and Geochemical Study of the Agios Ioannis Volcanic Rocks, Kamena Vourla Area, Greece

The Plio-Pleistocene volcanic center of Lichades is located in the Northern Euboean Gulf, at the western extremity of the North Anatolian Fault and it is one of the most neo-tectonically active areas in Greece. Volcanic rocks are exposed in the form of lava flows and/or domes mostly in the small islands (Lichades) offshore Kamena Vourla, as well as in a small outcrop in mainland, namely the Agios Ioannis area. Based on the results of the present study, the Agios Ioannis volcanic rocks are characterized as trachyandesites with high-K calc-alkaline affinities, similar to several volcanic rocks from the South Aegean Volcanic Arc. The petrological and mineral-chemical study reveal that the studied volcanic rocks are characterized by vitrophyric texture and a matrix dominated by glass, numerous randomly-oriented microlites of plagioclase and minor sanidine, clinopyroxene and amphibole. Phenocrysts comprise of plagioclase, olivine, quartz, clinopyroxene and amphibole. Plagioclase composition ranges from andesine to bytownite (An30-An73). Olivine cores are typically Mg-rich, and the rims display elevated FeO content. Clinopyroxenes display a narrow compositional range between augite and diopside, with the latter being more common. Amphiboles, are calcic and their composition ranges from tschermakite to tschermakitic hornblende. Mineralogical and geochemical similarities with other volcanic rocks in Greece such as Lesvos lamproites, may be helpful in understanding the genesis of the studied Agios Ioannis volcanics.