Geological setting and ediacaran–palaeozoic evolution of the western slope of the east european craton and adjacent regions

Abstract

A set of geological maps and geological cross-sections was prepared to document the geological setting of sedimentary basins developed on the western slope of the EEC and adjacent areas to the west. On the basis of these data and literature on the subject, the evolution of the sedimentary basins in the study area was reviewed, with special emphasis on the Ediacaran–Lower Palaeozoic basin. The basin originated during late Ediacaran rifting, related to the latest stages of breakup of the Precambrian super-continent Rodinia/Pannotia, associated with large-scale igneous activity. The rifting ultimately led to the formation of the Tornquist Ocean and subsequently, during the latest Ediacaran to Middle Ordovician, the SW margin of the newly formed Baltica became a passive continental margin. The upper Cambrian depocentre in the Biłgoraj-Narol Zone and the Łysogóry Block tentatively is interpreted as a small, narrow foredeep, related to the docking of the Małopolska Block to the western margin of Baltica. From the Late Ordovician through the Silurian, a gradual change to a collisional tectonic setting is observed across the entire SW margin of Baltica, as well as in the zones adjacent to it from the west, which together became the site of development of the extensive Caledonian foredeep basin, related to the convergence and collision of Avalonia and Baltica. The oblique character of the collision resulted in a prominent diachronism in the development of the foredeep basin. This refers to the initiation of basin subsidence, the starved basin phase, the main phase of rapid subsidence and supply of detritus from the west, and the termination of basin development. The Early Mississippian (Bretonian) phase of uplift and erosion and, to a lesser degree, also the Late Pennsylvanian one significantly affected the structure of the western EEC. During the Mississippian, extensive magmatic activity took place at the SW margin of East European Craton, in the region referred to here as the Baltic-Lublin Igneous Province.