Upper crustal structure and lower crustal and mantle character of the European continental lithosphere differ significantly from west to east. The processes of rifting of Phanerozoic western Europe's hotter, thinner crust compared with the more stable, thicker (45 vs 30 km) Proterozoic crust of the East European Craton is being investigated by EURO-PROBE case studies of western and eastern European sedimentary basins.
The Dnieper-Donets basin transects the southwestern part of the East European platform in a NW-SE direction, lying between the Ukrainian Shield and the Voronezh Massif. Rifting took place from early Frasnian until perhaps the late Visean and was accompanied by major volcanic activity. The distribution of both was affected by pre-existing basement fault systems. The syn- and post-rift sedimentary succession may be as thick as 20 km in the Donets Trough. Basin evolution and the present crustal geometry have been much affected by ''inversion'' during the Permian in association with Uralian orogenesis. Tectonic events of Bathonian-Oxfordian (approximately 168-154 Ma) and Turonian-Santonian (approximately 91-84 Ma) age are also recorded in the basin stratigraphy.
The Polish Trough lies along the boundary between the Phanerozoic and Proterozoic European crustal domains, coincident with the Trans-European Suture Zone. The presence of this rheological boundary may be paramount in structurally controlling the position of the Trough. Tectonic subsidence analysis indicates an initial (late) Rotliegendes-Early Triassic syn-rift phase of development. Subsequently, episodes of increased tectonic subsidence rate occurred during the Oxfordian-Tithonian (approximately 157-146 Ma) and beginning in the Cenomanian (approximately 95-90 Ma). The Oxfordian-Tithonian episode is likely the signature of a second extensional event (correlated with intensification of rifting within the Arctic-North Atlantic rift system) while the Cenomanian and later is a precursor to mild compressional, intraplate orogenic movements. Present-day crustal structure reflects the ''docking'' of Phanerozoic crust against the Proterozoic during Palaeozoic orogenies, Permo-Carboniferous wrenching and transtensional modifications leading to formation of the Polish Trough, as well as modifications during the Late Cretaceous-Early Tertiary inversion process.
|Number of pages||17|
|Publication status||Published - Jul 1993|
- NORTH-SEA BASIN
- CRUSTAL STRUCTURE
- ARCTIC CANADA
- EUREKAN OROGEN