Geology and ore deposits of the Urals

Abstract

The Urals is a N-S trending mountain range forming the geographic boundary between Europe and Asia. It represents a 2000 km long Paleozoic orogen, extending from the Islands of Novaya Zemlya in the north to the Aral Sea in the south. For a long time the information about Uralian geology was very scarce in the international literature. A significant breakthrough took place at the end of 20th century when the EUROPROBE and GEODE international projects started. In the frame of these projects, several seismic cross sections trough the Urals, together with detailed geological investigations, were carried out. The main results of these studies were published in a special Issue of Tectonophysics (1997) and in the Geophysical Monograph 132 "Mountain Building in the Uralides: Pangea to the Present" published by American Geophysical Union (AGU) in 2002 and in numerous other papers. In the last decade a lot of new mineralogical, petrological and geochemical data, particularly in isotope geochemistry and geochronology, were gathered. These new data represents the base for the need for a further look onto Uralian geology. This special issue of Mineralogy & Petrology contains a profound collections of new data, interpretations and discussional aspects on Uralian geology since 2002.The Urals belongs to the western flank of the huge transcontinental Uralo-Mongolian fold belt and comprises at least three billion years of geological history. Today we can distinguish between five major structural levels and epochs of the Urals development (see Puchkov 2013). The earliest Archean and later Meso-Neoproterozoic complexes, although related to the development of the Baltic craton and its eastern periphery, far before the Uralides existed, are incorporated in the Uralian orogen structure and sometimes they display traces of young Paleozoic events of the fold belt. The Archean rocks are represented by granulites of the Taratash complex, showing similarities to the granulites in the basement of the East-European platform. The MesoNeoproterozoic sedimentary and magmatic complexes witness the geotectonic development along the eastern margin of the Baltic Shield. This time was very productive regarding the formation of some important mineral deposits, such as siderite and magnesite within metasedimentary sequences (Prochaska and Krupenin 2012) and titano-magnetite ore associated with rift-related layered gabbro intrusions and others.The Paleozoic-Lower Jurassic period of time may be considered as the main stage of the development of the Uralides, covering a complete Wilson cycle: starting from the rifting of the Baltic continent after the Timanian orogeny, through formation of an oceanic basin, a passive continental margin and microcontinental blocks, to subduction, accompanied by a significant amount of volcanic eruptions, then arc-continent collision, continent-continent collision with granite magmatism, formation of a long chain of batholiths, and finally post-collisional extension with floodbasalt magmatism. The most important and famo...