(on Date of tectonic Geomorphology)
4th International conference on Geomorphology. Bologna. 1997. Abstracts. P. 175

The mid ocean ridges have its orographic continuation on continent, formed together with mountain chains of land united closed orogenic systems (Gavrilov, 1989, 1994). One can distinguish Indo-Pacific (In-P) and Indo-Atlantic (In-At) global ring structures. Their forms in Mercator projection are similar to ellipses. The length of big half-axis of In-P structure at equator is 10 th. km., the small is 8 th. km. In-At structure has the big half-axis 9,5 th. km., the small half-axis at 20ø W meridian is 7,5 th. km. The geological and geodynamic asymmetry about equator is characterized for these structures. There are zones of tectonic collision and granite magmatism in north within the limit of continents and, on the contrary, there are rifting processes and massed basalt eruption in south at ocean districts. In-P structure can have cosmogenic or endogenic origin, In-At - only endogenic one. These are the main elements of global system of ring structures (Fig 7). The anomal high concentrations of magmatic and metamorphic rocks areas, epicentres of earthquake and zones of tectonic collisions indicate that the ring structures are the main reflection forms of global and regional heat flows.