A new look at the altaids: A superorogenic complex in northern and central Asia as a factory of continental crust. part II: Palaeomagnetic data, reconstructions, crustal growth and global sea-level

The Altaids, an Ediacaran to early Cretaceous superorogenic complex in central and northwestern Asia, is bounded on the west by the Urals, on the south by the 'Intermediate Units' consisting of the Alay Microcontinent, the Tarim Block and south China carrying also the Manchuride Orogenic Belt and on the northeast by the Siberian Craton. Within this frame the superorogenic system evolved along two major arc systems, both in part rifted from the Siberian Craton. Throughout the evolution of the system there were no continental or arc collisions until the system was sealed by its final collision with the intermediate units in the late Palaeozoic and the closure of the Khangai-Khantey Ocean during the early Cretaceous. Available reliable palaeomagnetic data are consistent with the operation of only two major arc systems throughout the evolution of the superorogenic complex. During this evolu-2tion the Altaids seem to have generated some 3 million km3new continental crust which comes to some 0.5 km annually. This isabout one-third of the average rate of growth of the continental crust. The global eustatic sea-level seems to have been dominatedby the Altaid evolution only during the latest Carboniferous and the early Permian.