Marine/continental facies patterns, sequence stratigraphy and a gocad-3D-modelling of the carboniferous/permian-boundary of the Donetsk basin

Abstract

The Donetsk basin is the southeastern part of the intracratonic Pripyat-Dniepr-Donetsk Riftsystem, striking in a NW-SE direction from Belarus through Ukraine, over a distance of c. 1500 km the East-European Craton. The profiles of Late Carboniferous and Permian are characterised by interfingering marine-continental sediments in the Donetsk basin. Therefore, the possibility exists, to correlate the non-marine Carboniferous / Permian profiles of Western-Europe with the global marine stratigraphical scale. Detailed analyses of facies patterns and the reconstruction of the depositional setting are based on extensive fieldwork within the Donetsk basin. Microfacies analyses and micropalaeontological investigations of 110 limestone specimens were carried out. Furthermore, the straticraphic cross-sections (stratotype-key-section) of Upper Carboniferous and Lower Permian succession of Artemovsk area was correlated with the marine dominated stratotype section of the Pre-Donetsk basin, the well Skosyrskaya N 4199 (Alekseeva et al. 1983). The maximum flooding surfaces of the transgressive system tracts are represented by carbonate layers. SB and mfs are distinctive horizons throughout the studied area. The results of facies analysis and the sequence-stratigraphical deposition-model were used to develop a relative sea-level curve of the Donetsk basin. This was the base for the correlation of the relative sea-level curve of the Donetsk basin with the global sea-level curve as well as for the estimation of climatic fluctuations as controlling factors of the sea level fluctuations. A GOCAD-3D-model was developed to analyse the facies patterns in three dimensions and to understand subsidence processes during the basin evolution.