Clustering of arc volcanoes in subduction zones indicates along-arc variation in the physical condition of the underlying mantle where majority of arc magmas are generated. The sub-arc mantle is brought in from the back-arc largely by slab-driven mantle wedge flow. Dynamic processes in the back-arc, such as small-scale mantle convection, are likely to cause lateral variations in the back-arc ma...

chaldoran area in nw of iran has mesozoic oceanic crust basement. the studied rocks of this region can be divided into three groups: ophiolitic gabbros and pillow lavas, ophiolitic volcanoclastics and eocene lava flows. ophiolitic mafic rocks show continental volcanic arc natures and eocene lava flow shows oib-like nature. during the mesozoic,the chaldoran region was situated in the active cont...

Submerged arc welding is used widely in oil and gas industry construction for storage tanks, pressure vessels, shipbuilding and etc. One of the processes of submerged arc welding is back gouging operations. This paper presents a way to remove the back gouging operation from the submerged arc welding process. For this purpose, effects of submerged arc welding parameters onA516-70steel sample wer...

the area of study is located 120 km north-east of shahrood city. in terms of structure and geological classification, this area is located in the northern part of central iran zone. granitoids of troud ranging from monzonite to granite. the main minerals of granitoids are quartz, plagioclase, and orthose. the accessory minerals are biotite, hornblende, sphene, and opaque minerals. various textu...

New geochemical data including Sm/Nd isotopic data show evidence for an early Paleozoic arc/back-arc complex in the Nashoba terrane of southeastern New England. The Nashoba terrane lies between rocks of Ganderian affinity to the northwest and Avalonian affinity to the southeast. It consists of early Paleozoic mafic to felsic metavolcanic and metasedimentary rocks that were intruded by intermedi...

[1] Subduction zone magmas are characterized by high concentrations of H2O, presumably derived from the subducted plate and ultimately responsible for melting at this tectonic setting. Previous studies of the role of water during mantle melting beneath back-arc basins found positive correlations between the H2O concentration of the mantle (H2Oo) and the extent of melting (F), in contrast to the...

Back-arc basins such as the ones behind island-arcs of Western Pacific Ocean or in Mediterranean Sea are ubiquitous structures Earth. They extensional forming overriding plate subduction zones and similarly to continental rifts, they can exhibit different structural styles from narrow, localized rifting wide-rift extension. While these have been long recognized, factors controlling style extens...