Correlation between the structural pattern and the development of the hydrographic network in a portion of the Western Thessaly Basin (Greece)

Abstract

Abstract:In the context of the present study the structural pattern in the Western Thessaly Basin (Greece) has been examined, based on structural data collected from the entire study area that were further correlated to the hydrographic network. The structural pattern of the area was revealed from tectonic analysis. Additionally, the topography, stratigraphy and sedimentology of the study area were taken into account. GIS techniques were used to map the spatial distribution of the geological and tectonic features on the topographic relief of the area. The oldest structures are contractional in nature, deformed by normal faulting related to the extensional episodes initiated in Serravallian times. It is inferred that the orientation of the stress field in the area has changed several times: the N-S stress field which was dominant during Late Serravallian times changed to NW-SE (MessinianZanclian) up to E-W in Zanclian and subsequently to roughly NNW-SSE (in late Piacencian). The NE-SW stress that was dominant in Pleistocene became N-S in later times. In addition, some changes in orientation are also indicated for the transitional periods of the pre-mentioned extensional episodes, possibly related to local events, or as a block-related deformation. The development of the 7 th order streams is probably related to the N-S extensional faulting initiated in Pliocene times, while the dominant direction of the 6 th , 5 th and 4 th order streams is possibly connected with the presence of the NNE-SSW and NW-SE extensional faults. Finally, the lower order streams are probably related to the most recent E-W striking normal faults.

Engineering-geological conditions of the formations in the Western Thessaly basin, Greece

“…These are the hilly-mountainous region, with an absolute altitude ranging from 200 m up to more than 2,000 m and the lowland region, with an absolute altitude up to 200 m. These areas occupy 62.12 % and 37.88 % of the overall area, respectively. The hydrographic network is well developed with a significant surface runoff [28,29].…”

“…Thessaly is the most intensely cultivated and productive agricultural plain in Greece, mainly crossed by the Pinios River and surrounded by high mountains [29]. This plain is subdivided by a group of hills into two hydrogeological basins, the Western (Trikala-Karditsa plain) and the Eastern (Larisa plain) [28].…”

The risk of collapse in abandoned mine sites: the issue of data uncertainty

“…Of course a detailed knowledge of this boundary condition may lead to an improvement of the summary graph. -in general, a better analysis of the geomechanical properties of Flysch and Marl [59] as well as a complete analysis of the geological context [60] may lead to a great improvement in risk analysis.…”

The contribution of pattern recognition techniques in geomorphology and geology: the case study of Tinos Island (Cyclades, Aegean, Greece)

“…In our experiments concerning the automatic detection of the previously mentioned structures, we used the DEM corresponding to contour interval of 4 m (Figure 4(a)) aiming to accurately track the linearcurvilinear lineaments. Then, we digitized the normal faults on Tinos from the IGME map (Tinos-Yaros sheet, 1:50,000) and we overlaid the rose diagrams that resulted from the processing of the tectonic field measurements based on the methodology applied in previous works (Kamberis et al, 2012;Kokinou, 2015). Based on the results of (a) the automatic detection (Figure 7(a)) of the linear-curvilinear lineaments in the study area, (b) the already available geological information of the IGME map (Figures 2 and 7(b)) and (c) the tectonic field measurements (see rose diagrams in Figure 7(b); it is concluded that NE-SW to ENE-WSW and NW-SE to WSW-ESE trending normal geological faults characterized by steep slopes (>60°) prevail in the northern sector of the study area.…”