mafic and ultramafic plutonic igneous bodies, with small and big outcrops, between shemshak rock units (jurassic) are observed in east of imam zadeh hashem, in southern guilan province. ultramafic cumulates consist of clinopyroxenite, and plagiofer clinopyroxenite, olivine clinopyroxenite, and mafic rocks, based on mineralogy consist of gabbros, olivine gabbros, biotite gabbros and amphibole ga...

west directed subduction zones show common characteristics, such as low structural elevation, deep trench, steep slab and a conjugate back-arc basin that are opposite to those of the east directed subduction zones. the tectonomagmatic and metallogenic setting of the lut block is still a matter of debate and several hypotheses have been put forward. despite some authors denying the influence of ...

Boninites are unusual island arc volcanic rocks with high MgO (>9%), high Si0 2 (>55%) contents, and exceptionally low TiO 2 (<0.4%) contents. High MgO contents, MgO/(MgO + EFeO), Ni, Cr and Co contents indicate that boninites have equilibrated with mantle peridotite. Experimental petrologic studies and high Cr/(Cr + Al) in spinels in boninites suggest that they have separated from extremely re...

Subsurface geological cross sections of 0 200 m depth were constructed using a dense drilling database of the Osaka Plain in the intra-arc Osaka Basin of the Japan island arc, an active plate margin. The cross sections revealed the subsurface geological structures and the geometry of folding and faulting in the basin. The comparison between the constructed subsurface cross sections and the seis...

In regard to the tectonic history of the Lachlan Fold Belt, Aitchison and Buckman (2012) argued that "numerous aspects of the observed geology appear to be incompatible with the existing model" and that an "alternative model envisages arc-continent collision events (quantum tectonics) as a primary means of largescale continental growth". My purpose is to challenge these arguments and to questio...