Eurasia as the scene of the Late Cenozoic tectogenesis

This paper attempts to review the descriptions on the genetic series of neotectonic forms in Eurasia. Morphotectonically, the Eurasian continental block exhibits a radial-concentric pattern consist- ing of four kinds of tectonic units： platforms, rejuvenated and youthful mobile belts, and the continent- ocean transition zones. Vast areas of young and ancient platforms, such as Siberia, have experienced slow-rate Late-Cenozoic uplift and little interior deformation. The youthful orogenic belts are clustered into the giant Alpine-Himalayan megabelt. The rejuvenated mountain belts are characterized by a variety of structural-morphological types of orogens, such as domelike uplifts, block uplifts and intermountain basins. The continent-ocean transition zones in Eastern Asia, including marginal rifts and extensional basins, are resulted from interaction between the continental block and Pacific Ocean and Philippine Sea since the Late Cenozoic. One of the conspicuous features of Eurasia is that most areas lie in the largest geoid depression of the Earth, and the NS trending Uralian-Oman lineament expresses a break on the geoid slope, implying a relationship to deep structure, including density inhomogeneities, down- ward to the core-mantle interface. Besides, the Eurasian continent fully demonstrates morphotectonic and recent geodynamic features of the Northern Hemisphere of the Earth, just in contrast to that of the Southern Hemisphere. It is best to view the surface morphotectonics and deep structure of the Earth as a geodynamic ensemble which has spawned the large-scale geomorphic features on the surface.

A new species of extinct genus Lycopodites from Lower to Middle Jurassic sediments of Irkutsk coal basin (Eastern Siberia)

In Jurassic sediments of Siberia, remains of Lycopodites are rare in occurrence. They are represented by two species ： Lycopodites tenerrimus Heer, and L. （.9） trichiatus Pryn. This paper presents an emended diag- nosis of the species L.（.9） trichiatus Pryn., and the descriptions of two new species： Lycopodhes subulifolius sp. nov., and L. baikalensis sp. nov. from the Early-Middle Jurassic sediments of the Irkutsk coal basin, Eastern Siberia, Russia. As part of the research effort, it was found that the ecological preference of the new species was different： Lycopodites subulifolius sp. nov. grew in wet and open spaces, while Lycopodites baikalensis sp. nov. preferred to colonize young growth of bog forests.