Abstract
We found dark brownish rock veins and bodies in the oceanic crust of the northern Oman ophiolite. The outcrop belongs to the isotropic gabbro member located slightly below the lower boundary of the sheeted dyke complex along Wadi Bani Umar. This rock was formed by strong alteration of gabbro and dolerite altered by hydrothermal fluids and almost all minerals have been changed to chlorite. So we call this rock <chlorite rock.> In the wall rock gabbro and dolerite, Cpx is partially replaced by amphibole, and Opx, by aggregate of amphibole and chlorite. We analyzed wall rocks and chlorite rocks for mahor to trace elements to reveal genesis of the chlorite rocks and related chemical budget in the context of hydrothermal circulation in oceanic lithosphere.
