Geodynamics of polyorogenic zones: Case study from the Western Carpathians

Within the Alpine-Carpathian-Himalayan belt, the remnants of polyorogenic evolution are usually documented with a series of parallel suture zones of subequatorial course. In several cases some suture zones are interpreted as remnants of back-arc basins. In the Western Carpathians, the products of three principal Phanerozoic orogenic (Wilson) cycles were exemplarily documented – Variscan (Paleozoic), Paleo-Alpine (Mesozoic) and Neo-Alpine (Cenozoic) ones. The processes and products of the post-Cadomian Cenerian orogenesis are not treated in this article due to their ongoing research in the Western Carpathians, which is not yet completed. Based on presented geological and tectonic observations, as a driving force for polyorogenesis and multiple continental breakup a long time mantle convection (during a whole Phanerozoic eon) is interpreted, acting along a global subequatorial-course mantle bulge (ECMB) and parallel subequatorial-course mantle convection currents (ECMCCs). The submeridian zones with different kinematics are driven by submeridian-course mantle convection currents (MCMCCs), producing submeridian trending global rifts, but also subduction zones. Both systems of mantle convection currents – subequatorial (ECMB, ECMCCs), submeridian (MCMCCS) and their eventual interconnections, all briefly descriptively named as hot lines, are interpreted as principal drivers of global geodynamics. They are acting simultaneously with columnar mantle plumes (mantle diapirs). According to cited studies of different authors the heat for mantle convection currents and plumes is supplied by the thermonuclear fusion in innermost zones of the Earth. Combining the interpretation of global importance of mantle convection currents and their effect on processes within the lithosphere with the principles of plate tectonics, gives a basis for establishing a hypothesis of New Global Tectonics 2.0. For the simple and understandable description of a succession of orogenic cycles and their phases within polyorogenic evolution, including overprinting relations within tectonic and deformation phenomena, the methodology of XD labelling is applied in this contribution. Key words: polyorogenic processes, extended orogenic cycle, subequatorial-course mantle bulge (ECMB), subequatorial-course mantle convection current (ECMCC), submeridian-course mantle convection current (MCMCC), hot line, XD and MX labelling, Western Carpathians