A broad spectrum of variably altered igneous rocks with a wide range of grain sizes are compressed and heated over a wide range of pressure-temperature paths in subduction zones. Although experimental kinetic data cannot be extrapolated to predict the rates of blueschist and eclogite formation in nature, textural data from rocks indicate that transformation below temperatures of 150øC is minima...

this paper presents the new geochemical isotopes sr and nd, and the mineralization data for the south neyshabour volcanic rocks located in ne iran. based on the chemical classifications, the studied rocks are basaltic trachy andesite, trachy andesite, trachyte, and trachy dacite in composition. all the analyzed volcanic rocks display enrichment in light rare earth elements (lree) relative to th...

late miocene–pliocene calc-alkaline volcanic rocks are exposed southeast of isfahan in the urumieh-dokhtar magmatic belt. volcanic rocks consist of lava flows and domes, chiefly basaltic andesites, andesites and dacites. minerals in the volcanic rocks exhibit degrees of disequilibrium features. plagioclase as dominant mineral in these rocks generally displays reverse and oscillatory zoning; sie...

Volcanic rocks along the Panama Canal present a world-class opportunity to examine the relationship between arc magmatism, tectonic forcing, wet and dry magmas, and volcanic structures. Major and trace element geochemistry of Canal volcanic rocks indicate a significant petrologic transition at 21-25 Ma. Oligocene Bas Obispo Fm. rocks have large negative Nb-Ta anomalies, low HREE, fluid mobile e...

The northeast region of Birjand is located in Lut structural and geological province. In this area we can distinguish two separate volcanic rock groups: intermediate to acidic volcanic rocks, including dacite, andesite, rhyolite and trachyandesite; and basic rocks, including basaltic andesite, mugearite and basalt. In this region, intermediate to acidic rocks, which belong to the Eocene-Miocene...

introduction in the east and northeast of sanandaj in the qorveh-bijar-takab axis, there are series of basaltic composition volcanoes with quaternary age. the study area is part of the sanandaj-sirjan zone and is located between 47°52' and 47°57' e longitudes and 35°26 and '35°30' n latitudes. due to the location of the volcanic cone on pliocene clastic sediments and quaternary travertine, the ...