Geology of northwest Russia
The four major geological units of northwestern Russia
Northwestern Russia is comprised by four major units. South of this area are the basins of central European Russia. To the east lays the Ural fold zone.
The Baltic shield is a large Archean terrane. The majority of this terrane is covered with more modern sediments, but surface Archean rocks are more frequent in Kola and Karelia. The Baltic shield is larger than the part shown here and covers also large parts of Finland, Sweden and Norway
Mezen Basin or Mezenskaya depression
The Mezen basin is a rather boring area for the rochkhound, unless I have overseen something interesting. The whole basin is filled with a thick layer of Permian, Triassic and Jurassic sediments, mainly sandstone. There was some seismic activity in the late proterozoic (Riphean) in the form of rifts. But because there a a good kilometer of sediments on top, I do not expect shocking mineralogical finds in the Mezen basin.
The Timan belt is a fold belt between the Mezen basin and the Timan-Pechora basin. It is a late Precambrean fold belt.
Timan Pechora basin
The Timan Pechora basin is located between the Timan High and the Urals. The Timan-Pechora basin is best known for it's Vorkuta coal deposits. The basement is again a late proterozoic rift zone (Bailkalian =Riphean-Vendian). This basin is filled with up to 10km trick unmetamorphosed sediment. Only the western edge of the basin got deformed by the Uralian orogeny. Apart from rich petroleum occurrences and the Vorkuta coal the Pechora basin seems not too interesting for us mineral collectors.