بررسی توالی پوسته ای درونی افیولیتی قره قلی- باغ جر، شمال خاوری سبزوار ‏

The plutonic crustal sequence of garagoli-bagjar, located in ne sabzevar, is a part of ophiolitic association in the outer part of central iran ‎microcontinent. this sequence comprises cumulative olivine gabbro, pyroxene gabbro, isotropic gabbro, foliated gabbro and diabasic sheeted ‎dike complex, cross cut by the wherlitic intrusion, pegmatite gabbro and plagiogranite as small bodies, dikes and veins. this sequence is ‎comparable to upper gabbroic part of the well known ophiolite complex. these rocks construct a large tectonic slics thrusted over the ‎serpentinized peridotites and tectonically located under serpentinites. the cumulative gabbros change gradually to isotropic gabbro upwards ‎and at the same time isotropic gabbro change generally to diabasic sheeted dike complex. the structural measurements of magmatic layering ‎and strike of sheeted dikes, wherlitic intrusions, pegmatite gabbro and plagiogranite revealing e-w direction in the north of qaragoli and n-‎s direction in sw solymanieh might be comparable to the formation of plutoinc oceanic crust in fractures zone. the microscopic studies ‎exhibit that mesocumulate to heteradcumulate textures are abundant which indicate the open magmatic chamber of the supra-subduction ‎zones. the crystallization trends show diversity from olivine-plagioclase-clinopyroxene-orthopyroxene-amphibole trend (morb like) to ‎olivine-clinopyroxene-orthopyroxene-plagioclase-amphibole trend (as arc type). the study of the chemical analyses indicates diverse ‎compositions and primitive mantle normalized spider diagrams show depletion of nb with different enrichement of lree. the low-ti ‎character, locations in arc related cumulate and non cumulate fields, island arc to morb tectonomagmatic setting remark their supra-‎subduction origin which formed in late cretaceous. ‎