Branislav Trivić

Geological Units Classification of Multispectral Images by Using Support Vector Machines

Quantitative techniques for spatial prediction and classification in geological survey are developing rapidly. The recent applications of machine learning techniques confirm possibilities of their application in this field of research. The paper introduces Support Vector Machines, a method derived from recent achievements in the statistical learning theory, in classification of geological units based on the source of the Landsat multispectral images. The initial experiments suggest the usefulness of the proposed classification approach.

Glacial morphology of Serbia, with comments on the Pleistocene Glaciation of Monte Negro, Macedonia and Albania

Abstract Cvijic was the first to collect evidence on the glacial morphology of the Balkans, at the end of the 19th century. He reported the existence of glacial features on the three highest mountains of Serbia, Prokletije, Sara and Koritnik. The most recent investigations have been carried out using remote sensing techniques supplemented by field observations. This approach has led to the discovery of numerous cirques, glacial troughs, moraines and other characteristic features produced by Pleistocene glaciers in these mountains. Analysis of the positions and mutual relationships between the glacial features of these three mountain areas has enabled determination of the Pleistocene snowline altitude. Results indicate that it occurred at 1900 m elevation on the northern faces and 2200 m on the southern faces. These results indicate that the development of the Pleistocene, more precisely the Wurmian glaciation, was restricted to the highest elevations within the areas investigated. The type of glacier, which was formed, was dependent on the snowline position (i.e. on the topographic surface above it). Most glaciers developed in cirques, as hanging glaciers, and troughs, as valley glaciers. On Sara Mountain, where a vast plain existed at 2200-2400 m altitude, plateau-type glaciers developed.

The recent fault kinematics in the westernmost part of the Getic nappe system (Eastern Serbia): Evidence from fault slip and focal mechanism data

Abstract In this study we performed a calculation of the tectonic stress tensor based on fault slip data and all available focal mechanisms in order to determine the principal stress axes and the recent tectonic regime of the westernmost unit of the Getic nappe system (Gornjak-Ravanica Zone, Eastern Serbia). The study is based on a combined dataset involving paleostress analyses, the inversion of focal mechanisms and remote sensing. The results show dominant strike-slip kinematics with the maximal compression axis oriented NNE-SSW. This is compatible with a combined northward motion and counterclockwise rotation of the Adria plate as the controlling factor. However, the local stress field is also shown to be of great importance and is superimposed on the far-field stress. We managed to distinguish three areas with distinct seismic activity. The northern part of the research area is characterized by transtensional tectonics, possibly under the influence of the extension in the areas situated more to the northeast. The central and seismically most active part is dominated by strike-slip tectonics whereas the southern area is slightly transpressional, possibly under the influence of the rigid Moesian Platform situated to the east of the research area. The dominant active fault systems are oriented N-S (to NE-SW) and NW-SE and they occur as structures of either regional or local significance. Regional structures are active in the northern and central part of the study area, while the active fault systems in the southern part are marked as locally important. This study suggests that seismicity of this area is controlled by the release of accumulated stress at local accommodation zones which are favourably oriented in respect to the active regional stress field.

Investigating distant effects of the Moesian promontory: brittle tectonics along the western boundary of the Getic unit (East Serbia)

In this study, we report evidence for brittle deformation in a part of the Carpatho–Balkan orogen, which is explained in terms of effects of the rigid Moesian promontory of the European plate on fault kinematics in East Serbia. We focus on the westernmost part of the Getic Unit of the East Serbian Carpatho–Balkanides, i.e. the Gornjak–Ravanica Unit, located between two main thrusts that were repeatedly activated from Early Cretaceous to recent times. We combine a new data set on fault kinematics and tectonic paleostress tensors, with literature data about neotectonic and recent fault activity, in order to reconstruct brittle tectonic events that were active in this area since Oligocene times. Two brittle tectonic phases were distinguished. The older phase was most probably active from the Oligocene to the end of the middle Miocene, and was characterized by the activation of faults that accommodated a complex sequence of clockwise rotations of the Dacia mega-unit around the rigid Moesian promontory. The younger deformational phase most likely started in the late Miocene and is probably still active in recent time. It is characterized by strike-slip tectonics, resulting from the far-field stress generated by the collision of the Adriatic microplate, the Moesian promontory and the tectonic units in between. This stress field is shown to be highly heterogeneous even in the relatively small research area; local areas of transtension and transpression have also been very important in controlling the fault kinematics in the western part of the Getic Unit.

Recent Landform Evolution in Serbia

Serbia can be divided into two major geographical units: the Vojvodina Plain and the southern hills and mountains. In the plain fluvial and aeolian processes and landforms on loess are typical, while south of the Sava and Danube rivers, sheet and gully erosion, mass movements, fluvial, karstic, and fluvio-karstic landform evolution are most influential in shaping the present topography. Among the now inactive geomorphic processes tectonic movements, volcanic activity, coastal, glacial, and aeolian evolution have left behind traces still detectable in modern topography. Some examples of rapid topographic change resulting in the most spectacular landforms (landslides, rockfalls, natural bridges, and rock pinnacles) are presented and described in detail from various regions of Serbia.