| Keywords [eng] |
Backstripping methodology, Baltic basin, subsidence analysis, subsidence trends, tectonic subsidence, total subsidence, subsidence rate, geodynamic evolution. |
| Abstract [eng] |
The masters thesis research is aimed to reconstruct subsidence trends of the central part of the Baltic basin, with focus mainly on the Lithuanian territory, by adopting backstripping methodology to construct and analyze subsidence curves to get insights of basin‘s geodynamic evolution. In total, the work consisted in 4 different chapters: The work overviewed the geological and tectonic setting, and the previous investigations in the Baltic basin. A description of the geological structure and the geodynamic evolution of the area of interest were performed to situate the general view of the study domain. The second chapter focused on the methodological part, including general procedure of backstripping methods, and, more importantly, the procedure applied in this thesis, such as input files preparation from the actual well data and subsidence curves construction from the backstripped results. A thorough analysis and interpretation of the subsidence curves were performed considering the different trends distinguishable from the curves, and all the findings were summarized in 6 different tables. The summarizing chapter was dedicated to the discussions part which consisted in structuration of the Baltic basin evolution throughout different stratigraphic period of times. In clear, the masters thesis research provided insights on the Baltic basin subsidence evolution going from the passive continental margin stage, active continental margin stage, climax of the active continental margin stage, intracratonic centred basin stage, tilted extensional and compressional basin stages. The Carboniferous uplift wasn‘t observed in all the studied wells. During early Carboniferous – Permian period, a regression of the basin was noted in the latter part of Famennian time. The western and southern parts of the basin were high uplifted. Moreover, the sedimentation rates calculated had shown highest values from the westernmost wells including the Latvian offshore wells, and the lowest sedimentation rates were found in the eastern part of the area of consideration. The calculated difference values between maximum total subsidence and maximum tectonic subsidence have shown higher values from wells located in the western part of the studied area, leading to conclude that the widening of the basin was predominantly west – East orientation, with higher accommodation space created in the west compared to the central and eastern parts. |
