The geology and magmatism of the northern Mariana Trough (NMT) represent a type example for development back-arc basin (BAB). It is mature spreading center in south propagating northward via rifting arc rear lithosphere response to trench retreat overriding plate extension space time. thus essential fully characterize its tectonomagmatic processes that are potentially global significance. For t...

Abstract Recognition of any intra-oceanic arc-trench system (IOAS) could provide invaluable information on the tectonic framework and geodynamic evolution vanished ocean basin. The Tanjianshan Complex mafic-ultramafic rocks along North Qaidam ultra-high pressure metamorphic belt in NW China record subduction process Proto-Tethyan Ocean. Four lithotectonic units, including island arc, ophiolite,...

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...

Tectonic collision between South America and Panama began at 23–25 Ma. The collision is signifi cant because it ultimately led to development of the Panamanian Isthmus, which in turn had wide-ranging oceanic, climatic, biologic, and tectonic implications. Within the Panama Canal Zone, volcanic activity transitioned from hydrous mantle-wedge−derived arc magmatism to localized extensional arc mag...

Noble gas concentrations and isotopic compositions have been measured in eight samples of pillow basalt glasses collected from seven different localities along 250 km of the Mariana Trough spreading and rifting axis. The samples have uniform and mid-ocean ridge basalt (MORB)-like He/He values of 9±12 ́ 10 (6.4±8.6 times atmospheric) despite large variations in He. Concentrations of the noble ga...

The Izu-Bonin arc (IBA) has been colliding with the Honshu arc since the middle Miocene, which together form the active Izu arc-arc collision zone (ICZ) in central Japan. To understand the entire collisional system, we have used refraction/wide-angle reflection data to model velocity structures of the Honshu arc, northwest of the ICZ. The seismic data indicate that the upper 4-km crust of the H...

Extensional and transtensional continental arc basins preserve very thick, continuous sequences and are an important contributor to the growth of continents; therefore, it is important to understand how they evolve. In this chapter, I describe four continental arc basin types, using Mesozoic to Cenozoic case studies from the SW US: (1) early-stage, low-lying extensional; (2) early-stage, low-ly...

We present isotopic analysis of helium in hydrothermal fluids from the Manus back-arc basin, collected during the French-Japanese Manusflux and Manaute cruises in 1995 and 2000, respectively. The helium isotope composition of the fluids is comparable to that measured elsewhere in similar subduction environments, with 3He/4He values (7.4 to 7.9 Ra) slightly lower than typical MORB values, except...