Crystalline rocks of the Marmarosh massif of the Eastern Carpathians, taking into account based on the plate tectonics theory analysis of their characteristics and tectonic setting and the constructed cross-section of the local gravity anomalies, have been formed by the metamorphic rocks of Ryphean, Vendian, Cambrian and late Paleozoic as well as by the Meso-Cainozoic rocks in the south-eastern passive margin of the European plate. But later in conditions of collision and gently sloping subduction of substrate during the Cretaceous-Paleogene these rocks have been shifted from their substrate and became a part of Marmarosh nappes of the Eastern Carpathians.