Geodetic geodynamic studies were conducted in the Wrocław Plain, situated in the SE part of the Central European Subsidence Zone (CESZ). The boundaries of this plain coincide with the outline of the rhomboidal Cainozoic Wrocław Basin. This area has been chosen for detailed examination taking into account the results of previous geodynamic research, pointing to constant subsidence of the Wrocław region. Analysis of drainage network and changeable thicknesses of the Neogene an d Quaternary strata also indicates weak, although stable subsidence of the central part of the Silesian Lowland and relative, small-scale uplift of the Fore-Sudetic region situated in thes outh and an area placed north of the Odra River valley. The studies consisted in measuring elevation changes of benchmarks along lines of precise levelling during 1956-1999 period, establishing a GPS network points, as well as measuring and processing of GPS data acquired during 2008-2010 time span. Displacements of benchmarks of precise levelling lines point to block-type mobility of structures located in the SE part of the CESZ, while GPS measurements indicate deformations related to bending of the Cainozoic sedimentary cover underlain by metamorphic bedrock and Permo-Mesozoic strata. Three years of observations enable us to distinguish two zones typified by compressive deformations being coincident with subsiding areas. One of these zones strikes NW-SE and marks the CESZ axis, the second one, oriented NNW-SSE, fo llows the orientation of a deeply buried Carboniferous-Permian tectonic graben (the Eastern Fore-Sudetic Basin) and a much shallower trough filled with Cretaceous strata in the Opole region. Uplift typifies the Fore-Sudetic Block as well as areas situated close to Opole town and north of the Odra River valley., Piotr Grzempowski, Janusz Badura, Stefan Cacoń, Jan Kapłon, Witold Rohm and Bogusław Przybylski., and Obsahuje bibliografické odkazy
Analysis of benchmark height changes along national 1st order precise levelling lines crossing the Middle Odra Fault Zone in the Wroclaw area has been presented in this paper. The zone separates Fore-Sudetic Block from the Fore-Sudetic Monocline and is one of the main geological structures in Lower Silesia. Five national precise levelling lines cross the research area: Ząbkowice Śląskie - Wrocław, Syców - Wrocław, Karczów - Wrocław, Kawice - Wrocław oraz Krotoszyn - Wrocław. These levelling lines were measured in 1956-58, 1975-80 and 1999. Changes of benchmark heights have been presented in comparison with geological cross-sections made along the levelling lines. In the result, areas of the greatest relative vertical displacements correlated with geology and tectonics have been found., Piotr Grzempowski, Janusz Badura, Stefan Cacoń and Bogusław Przybylski., and Obsahuje bibliografii
We analysed a nearly 133-km-long portion of the Sudetic Marginal Fault (SMF) in Poland (99.7 km) and the Czech Republic (33.8 km), comprised between Złotoryja in the NW and Jesenik in the SE. The fault trace has been subdivided into fifteen segments showing different orientation (N29°W to N56°W, and even N111°W SE of Złoty Stok), geological setting, length (8.8-22.9 km in Poland and 1.4-7.5 km in the Czech Republic), and height of the fault- and fault-line scarps (5-75 m to 200-360 m). Orientation of the entire fault trace approaches N41° W, and the mountain front sinuosity amounts to 1.051. Individual fault segments bear a flight of two to five tiers of triangular facets, showing differentiated state of preservation and degree of erosional remodelling. The highest triangular facets are confined to Rychlebské (Złote) and Sowie Mts. This tiering points to at least five episodes of uplift of the SMF footwall, starting shortly after 31 Ma, i.e. after basalts of the Sichów Hills area were displaced by the fault, and most probably postdating 7-5 Ma time interval, during which rapid cooling and exhumation of the Sowie Góry Mts. massif took place. Morphometric parameters of 244 small catchment areas of streams that dissect the fault scarp include, i.a. elongation, relief, and average slope of individual catchment areas, together with values of the valley flo or width to valley height ratios. These figures point to moderate tectonic activity of the SMF and allow us to conclude about Quaternary uplift, particularly important in the Sowie and Rychlebské (Złote) segments., Janusz Badura, Witold Zuchiewicz, Petra Štěpančiková, Bogusław Przybylski, Bernard Kontny and Stefan Cacoń., and Obsahuje bibliografické odkazy