REGIONAL GEOLOGY AND TECTONIC EVOLUTION OF THE WESTERN EUROASIAN ARCTIC

The western Euroasian Arctic area is located in the large area from the east coast of the North Atlantic in the west to Verkhoyansk Mountains in the east. It is quite complicated in geology. According to the basic geological features, it could be divided to two provinces, say western province and eastern province. In the western province,there are various tectonic units, such as the Precambrian Baltica craton, Siberian craton and Svalbard microplate surrounded by the Timanian, Caledonian and Uralian Orogens, while in the eastern area there occur the Siberian craton and Early Cretaceous Verkhoyansk Orogen. It has experimented four major tectonic events:1) the Timanian orogeny by the latest Neoproterozoic to earliest Cambrian resulted in the collision between Svalbard-Kara microplate and Baltic, and the Timanide was formed; 2) the Caledonian orogeny from Ordovician to Silurian resulted in the Baltic colliding with Siberia, and formed the Caledonite. 3) The collision of Siberia with Kazakhstan and Baltic in late Palaeozoic resulted in the Ural-Novaya Zemlya-Taimy Orogen. 4) The collision of the Kolyma-Omolon Composite Superterrane and Alaska-Chukota microplate with the continental magin of Siberia, resulted in the formation of the Verkhoyansk Orogen and South Anyui Suture.