Oceanic and Island-Arc Ophiolites in Southeastern Gorny Altai

Structural, petrochemical, and geochemical data are used to recognize two types of ophiolites, oceanic and island-arc, which are part of a nappe-scaly structure. The oceanic ophiolites in the form of tectonized ultrabasic plates and serpentinite melange with garnet amphibolite and eclogite blocks are part of an accretion wedge (pressures up to 13–14 kbar and temperatures to 620–700 °C). The island-arc ophiolites characterize a primitive island arc and consist of layered pyroxenite-gabbro series, sills and dikes, tholeiitic and boninitic extrusive bodies.