[1] Abstract: We propose that across-arc differences in the geochemistry of Izu-Bonin arc magmas are controlled by the addition of fertile-slab fluids to depleted mantle at the volcanic front, and residual-slab fluids to fertile mantle in the back arc without slab melting or contemporaneous back arc spreading. The arc consists of a volcanic front, an extensional zone, and seamount chains (the W...

miocene silisiclastic sediments in binalood zone consist of three lithofacies group including gravelly (gmm, gcm, gci, gh, gt, gp), sandy (st, sm, sh, sp, ss, sl) and muddy (fm, fl). gravelly lithofacies are generally massive and mainly consist of volcanic and sedimentary lithic in different size. sandy lithofacies are composed of litharenite and feldespathic volcanicarenite and rock fragments ...

Petrography and chemistry of minerals showing that Eocene alkaline volcanic rocks in southwestern of Germi (Talesh zone, NW Iran) mostly have basaltic composition. Mineralogically these rocks are composed of diopsidic clinopyroxene and labradoritic plagioclase phenocrysts. The microlithic and glassy groundmass composed of sanidine, clinopyroxene, biotite, pargasitic amphibole and magnetite asso...

1-Introduction Damavand volcano was formed by explosive and non-explosive eruptions on the old eroded rock units (Mesozoic and older) of Central Alborz during the Quaternary period and formed two huge cone (Old and Young Damavand). Davidson et al. (2004) determined the time of Old-Damavand activity from 1800 to 800 thousand years ago by measuring Ar/Ar and U-Th/He methods. According to their ...

Crustal assimilation (e.g. Hildreth and Moorbath, 1988) and/or subduction erosion (e.g. Stern, 1991; Kay et al., 2005) are believed to control the geochemical variations along the northern portion of the Chilean Southern Volcanic Zone. In order to evaluate these hypotheses, we present a comprehensive geochemical data set (major and trace elements and O–Sr–Nd–Hf–Pb isotopes) from Holocene primar...