Horváth, F., S. Cloething 1996: Stress-induced late-stage subsidence anomalies in the Pannonianbasin. - Tectonophysics, 266, pp. 287 - 300 .
Stress-induced late-stage subsidence anomalies in the Pannonianbasin
The crown architecture of the trees has only researched in the last decades. In this respect Hallé’s study is very important (Hallé et al. 1978), in this they described 23 architectural models about tropical tree species. This kind of model can not use for trees, which are in the temperate zone, therefore Pfisterer and Roloff (2010) worked out another architectural models. This present study gives a classification about the architectural models and types of native, frequently cultivated alien tree and shrub species in the Pannonian Basin. We classified the species into 8 architectural models, within it are 17 different architectural types. Three architectural models (Attims, Leeuwenberg, Scarrone) and 5 architectural types (Aesculus, Cryptomeria, Syringa, Thuja, Tsuga) only contain alien species.
We present the results of a fault reactivation study that used the analog modeling technique. The modeled tectonic processes represent the formation and subsequent deformation of the Derecske Trough and have implications for the evolution of the entire Pannonian basin system. Structural inversion of former thrusts led to normal faulting during the Miocene and corresponds to the formation, whereas subsequent reactivation of these faults in a strike-slip manner during the late Miocene to Quaternary represents neotectonic deformation of the basin. Modeling results show that reactivation of thrust faults in a transtensional manner can occur in a broad range of dip angles, and of angular differences between the maximum principal stress axis and the strike of the fault. The reactivation pattern of strike-slip zones in sandbox models critically depends on the orientation of the fault system with respect to the confining stress field, on the material property of the sand, and on the presence of a lubricant layer, representing a potential detachment horizon at the base of the models. The shear zones at the border zones of the Derecske pull-apart basin are prone to further reactivation, regarding the present-day stress field in the area. These inferences are confirmed by the recent seismic activity of the area, and point to the key importance of fault reactivation studies during seismic hazard assessment.
The mechanism of earthquake occurrence in the Pannonian Basin is not clear in most cases (in other words, it is often not possible to find a relationship between the location of epicenters and the elements of the maps of recent tectonic movements), hence a GIS has been created in order to clarify the origin of these events. The special seismological GIS includes all relevant information (maps and joint database) concerned with earthquakes covering the whole territory of Hungary. GIS contains the following maps: special macro- and microseismic epicenters and their parameters; different active tectonic fault maps; digital terrain model of the recent relief; digital terrain models of different geological basements; appropriate geophysical anomaly maps; Quaternary sediment thickness; recent rivers, water streams and settlements. GIS enables us to carry out special operations between different layers by applying its tools in order to reveal the recent tectonic movements and to throw light upon the generation of possible earthquake occurrences. Results of the present investigation in GIS revealed that significant relation exists between the earthquake foci and recent tectonic lines. Some foci, however, can not be related to fracture lines. One part of earthquakes showed agreement with Pre-Tertiary basement areas of considerable slope, with the recent tectonic elements of Geomorphological maps and with the piedmonts of the North Hungarian Range. Some traces of recent movements have been found with the help of the multiplication map of Quaternary sediment thickness map and Recent relief (Digital Elevation Model).
Tomographic P-wave velocity inversion has been performed for the Pannonian region using first arrival times of local and regional events from the bulletins of the International Seismological Center and the Hungarian Earthquake Bulletins. The input data consist of 4071 arrival times of 570 events. A three-dimensional velocity model has been gained by joint hypocenter-velocity inversion on a coarse and a fine non-uniform cartesian grid of nodes. The initial one-dimensional model was determined by genetic algorithm. A bending ray tracer has been used to calculate the theoretical travel times and ray paths. The reliability of the inverted velocity parameters were checked by the checkerboard method and by the analysis of the model resolution matrix. The results are generally in agreement with the known structural characteristics of the Pannonian Basin. An interesting high-velocity anomaly has been found in the uppermost mantle beneath the southern part of the Great Hungarian Plain.
Two effects have been studied concerning the former Wiese arrows and the newly determined complex induction vectors in the Pannonian backarc basin (Hungary): the remote effect of the curved Carpathian Conductivity Anomaly (CA) on the direction of the long period vectors, the local effect of the thickness (or conductance) of the conductive sediments on the induction vectors. The curvature of the Carpathian CA is clearly seen in the direction of the induction vectors as a remote effect dividing the Pannonian Basin into two great parts from this point of view. Following Zhang et al. (1993) who stated that the length (absolute value) of the induction vector becomes also constant in the “S-interval” as the magnetotelluric (MT) impedance which is related to the conductance of the sedimentary cover, it has been studied whether there is also any relation between the length of the induction vectors and the conductance of the same sedimentary cover (or thickness of sediment if its resistivity is constant). Due to the structural inhomogeneities to which the induction vectors are very sensitive, and to their great remote (side) effect, only a weak statistical relation has been found, nevertheless, its trend could be approximated by Ritter and Banks' (1998) theory. Exceptional cases are demonstrated.
.Karamata, D. Stefanović 2001: Cretaceous-Tertiary evolution of terranes at the southern margin of the PannonianBasin. - PANCARDI 2001, A.Adam, Szarka, L. and J. Szendroi (Eds): II Abstracts, Geod. and Geoph. Res. Inst., Hung. Acad. of Sciences, DO-3, Sopron
Our paper presents the general overview of the current geophysical results, which helps to improve the geophysical image and the lithospheric structure of the Carpathian-Pannonian Basin region. Two different geophysical methods have been applied for the study of the structure and composition of the lithosphere as well as for determination of the lithospheric thermal structure. Firstly, integrated 2D modeling of gravity, geoid, topography and surface heat flow data was performed. Secondly, based on the results of the CELEBRATION 2000 seismic experiment, a large-scale 3D lithospheric gravity model was developed. The resulting map of the lithospheric thickness shows important variations in lithospheric thickness across the chain as well as along strike of the Carpathian arc. The sediment stripped gravity map is characterized by minima in the Eastern Alps and Western Carpathians. The maxima are observed in the Pannonian Back-arc Basin system, Bohemian Massif, Fore-Sudetic Monocline, Bruno-Silesian unit (BSU), Lublin Trough and partly in the Holy Cross Mts. and Malopolska unit. The Western Carpathian gravity minimum is a result of the interference of two main gravity effects. The first one comes from the lowdensity sediments of the Outer Western Carpathians and Carpathian Foredeep. The second one is due to the thick low-density upper and middle crust, reaching up to 25 km. The sediment stripped anomaly in the Pannonian Back-arc Basin system is characterized by gravity high that is a result of the gravity effect of the anomalously shallow Moho. The most dominant feature of the complete stripped gravity map is the abrupt change of the positive anomalies along the Pieniny Klippen Belt zone. The complete residual anomaly of the Pannonian Back-arc Basin system and the Western Carpathian orogen is characterized by a long-wavelength gravity low. The lowest values are associated with the thick low-density upper and middle crust of the Inner Western Carpathians. The European Platform is characterized by significantly denser crust with respect to the less dense crust of the microplates ALCAPA and Tisza-Dacia. That is why we suggest that the European platform represents consolidated, while the Carpathian-Pannonian Basin region un-consolidated crust.