the iranian east magmatic assemblage (iema) in the central lut region, hosted porphyry and vein-type polymetallic mineralization. the galechah-shurab mining district is located in nw of the iema. volcanic and subvolcanic bodies in the area are composed of calc-alkaline porphyry quartz-latite, porphyry dacite and rhyodacite and hornblende-biotite andesite, equivalent to i-type granite. they empl...

Abstract The Takidani pluton (1·1–1·6 Ma) represents a shallow magmatic reservoir at the base of an exhumed caldera floor. deposits two large caldera-forming eruptions, Nyukawa Pyroclastic Flow Deposit (1·76 Ma; crystal-rich dacite) and Chayano Tuff Ebisutoge Deposits (1·75 sequence crystal-poor rhyolite), are distributed concentrically around pluton. We use major trace element chemistry whole-...

The diffusion of water in dacitic and andesitic melts was investigated at temperatures of 1458 to 1858 K and pressures between 0.5 and 1.5 GPa using the diffusion couple technique. Pairs of nominally dry glasses and hydrous glasses containing between 1.5 and 6.3 wt.% dissolved H2O were heated for 60 to 480 s in a piston cylinder apparatus. Concentration profiles of hydrous species (OH groups an...

Abstract Hekla is an elongate volcano that lies at the intersection of South Iceland Seismic Zone and Eastern Volcanic Zone. We report major trace element, oxygen isotopic, H2O analyses on rocks, glass, melt inclusions, minerals from almost all historical lavas tephra deposits. This new dataset confirms remarkable observation not only are many eruptions compositionally zoned felsic to mafic, bu...

Streck et al. (2007) state that primitive andesite lavas (Mg# > 0.6; 53–63 wt% SiO 2 ) from Mt. Shasta are not primary melts, but instead are mixtures of evolved, high-Sr/Y, low-Mg# dacite with primary, low-Sr/Y, high-Mg# basalt. They propose that this mixing forms primitive andesites worldwide, and they dismiss the idea that primitive andesite is an end member in arc magmatism. Magma mixing is...