Rocks ranging in composition from trondhjemite to diorite (plagiogranites) have been recovered from ocean ridges and are common constituents of ophiolites. Velocities and densities of diorite and trondhjemite from the MidAtlantic Ridge are shown to differ significantly from similar properties of metadolerite and gabbro. Compressional (V p) and shear (V s.>velocities of plagiogranites are relati...

baft ophiolitic – mélange belt is a part of the ophiolite melange belt of central iran whose genesis is considered as an environment related to tethys subduction at upper cretaceous. major part of intrusive masses of baft ophiolitic – melange form gabbros with the inequigranular texture fine to coarse and pegmatitic, plagiogranites also with inequigranular general texture have been developed wi...

Abstract The growth of continental crust through melt extraction from the mantle is a critical component chemical evolution Earth and development plate tectonics. However, mechanisms involved remain debated. Here, we conduct petrological geochemical analyses on large (up to 5000 km 2 ) granitoid body in Arabian-Nubian shield near El-Shadli, Egypt. We identify these rocks as largest known plagio...

The Great Serpentinite Belt of eastern Australia is a ∼1500 km long dismembered ophiolite assumed to be Cambrian based on studies small (typically <50 m2) exotic meta-igneous inclusions despite contrasting ages (Cambrian—Devonian) and complex P-T histories. To overcome these issues, we studied ∼18 km2 coherent block that provides robust geological context sampling the ophiolite. Zircon U-Pb-Hf-...

We suggest a new explanation for the presence of crustally derived zircons in the upper-mantle rocks of ophiolitic complexes, as an alternative to subduction-related models. Integrated isotopic (U-Pb, Hf, and O isotopes) and trace-element data for zircons from the Tumut ophiolitic complex (southeast Australia) indicate that these grains are related to granitic magmatism and were introduced into...