Missoni S.,University of Leoben |
Gawlick H.-J.,University of Leoben |
Sudar M.N.,University of Belgrade |
Jovanovic D.,Geological Institute of Serbia |
Lein R.,University of Vienna
Facies | Year: 2012
A kilometer-sized block in the Sirogojno carbonate-clastic mélange provides a complete succession of the Wetterstein Carbonate Platform evolution. The platform starts its progradation in Early Carnian times over hemipelagic Late Ladinian cherty limestones with fine-grained allodapic limestone intercalations. Shallow-water reef-slope, reefal to back-reef/lagoonal limestones evolved in the Early Carnian. The top of the platform is recrystallized and partly slightly dolomitized, and in parts karstification is visible. After a period of omission caused by uplift, new subsidence started in the early Late Carnian. This is documented by a flooding respectively drowning sequence of the same age, starting with reefal carbonates and rapidly followed by hemipelagic-influenced limestones. The evolution of the onset and the drowning of the Wetterstein Carbonate Platform prove a paleogeographic derivation of this block from the outer shelf-area facing the Neotethys Ocean, but still in a shallow-water carbonate platform position transitional to the Hallstatt facies zone. This paleogeographic position is especially confirmed by the new pulse of subsidence in the Late Carnian after a long lasting phase of omission. The evolution of the Wetterstein Carbonate Platform in the Inner Dinarides corresponds to successions known from the Northern Calcareous Alps or the southern Western Carpathians. In the Late Triassic both regions belong to the same northeast-southwest striking shelf area facing the Neotethys Ocean to the east and southeast, respectively. © 2011 Springer-Verlag.
Hips K.,Hungarian Academy of Sciences |
Haas J.,Hungarian Academy of Sciences |
Vido M.,Eotvos Lorand Geophysical Institute |
Barna Z.,Geological Institute of Hungary |
And 3 more authors.
Sedimentology | Year: 2011
A peculiar facies of the Norian-Rhaetian Dachstein-type platform carbonates, which contains large amounts of blackened bioclasts and dissolutional cavities filled by cements and internal sediments, occurs in the Zlatibor Mountains, Serbia. Microfacies investigations revealed that the blackened bioclasts are predominantly Solenoporaceae, with a finely crystalline, originally aragonite skeleton of fine cellular structure. Blackening of other bioclasts also occurs subordinately. Solenoporacean-dominated reefs, developed behind the platform margin patch-reef tract, were the main source of sand-sized detritus. The blackened and other non-blackened bioclasts are incorporated in automicrite cement. Radiaxial fibrous calcite cements in the dissolutional cavities are also black, dark grey or white. Reworked black pebbles were reported from many occurrences of peritidal deposits; in those cases, the blackening took place under pedogenic, meteoric diagenetic conditions. In contrast, in the inner platform deposits of the Ilidža Limestone, the blackening of bioclasts occurred in a marine-meteoric mixing-zone, as indicated by petrographic features and geochemical data of the skeleton-replacing calcite crystals. Attributes of mixing-zone pore waters were controlled by mixing corrosion, different solubility of carbonate minerals and microbial decomposition of organic matter. In the moderate-energy inner platform environment, large amounts of microbial organic tissue were accumulated and subsequently decomposed, triggering selective blackening in the course of early, shallow burial diagenesis. The δ18O and δ13C values of the mixing-zone precipitates and replacive calcite do not produce a linear mixing trend. Variation mainly resulted from microbial decomposition of organic matter that occurred under mixing-zone conditions. The paragenetic sequence implies cyclic diagenetic conditions that were determined by marine, meteoric and mixing-zone pore fluids. The diagenetic cycles were controlled by sea-level fluctuations of moderate amplitude under a semi-arid to semi-humid climate. © 2010 The Authors. Journal compilation © 2010 International Association of Sedimentologists.
Momcilovic M.,University of Belgrade |
Kovacevic J.,Geological Institute of Serbia |
Tanic M.,Training Center |
Crossed D Signorcrossed D Signevic M.,University of Nis |
And 2 more authors.
Environmental Monitoring and Assessment | Year: 2013
The activity concentrations of natural radionuclides in soils from the area affected by uranium mining at Stara Planina Mountain in Serbia were studied and compared with the results obtained from an area with no mining activities (background area). In the affected area, the activity concentrations ranged from 1.75 to 19.2 mg kg-1 for uranium and from 1.57 to 26.9 mg kg -1 for thorium which is several-fold higher than those in the background area. The Th/U, K/U, and K/Th activity ratios were also determined and compared with data from similar studies worldwide. External gamma dose rate in the air due to uranium, thorium, and potassium at 1 m above ground level in the area affected by uranium mining was found to be 91.3 nGy h-1, i.e., about two-fold higher than that in background area. The results of this preliminary study indicate the importance of radiological evaluation of the area and implementation of remedial measures in order to prevent further dispersion of radionuclides in the environment. © 2012 Springer Science+Business Media B.V.
Carevic I.,University of Belgrade |
Radulovic B.,University of Belgrade |
Ljubovic-Obradovic D.,Geological Institute of Serbia |
Rabrenovic D.,University of Belgrade |
Jovanovic V.,University of Belgrade
Neues Jahrbuch fur Geologie und Palaontologie - Abhandlungen | Year: 2011
The Middle Jurassic sediments of the Getic of Carpatho-Balkanides in the trans-border area of Serbia and Romania are insufficiently studied. This zone is composed mainly of pre-Jurassic metamorphic rocks and the Upper Jurassic/Lower Cretaceous limestones. The palaeontological and sedimentological study of the Middle Jurassic deposits of the Brnjica River (Carpatho-Balkanides), which is one of the rare well-exposed outcrops, is being carried out for the first time. The dominant lithologies are grey and yellow sandy limestones and marly limestones with intercalations of reddish shales characterized by low-diversity fossil assemblages dominated by molluscs. Eleven bivalve taxa are determined for the first time in the studied area. Litho- and biofacies analysis in the marine Jurassic strata are reported based on bivalve assemblages with additional data from brachiopods, ammonites and microfossils. The age of the fossil association is determined as the Upper Bajocian and Bathonian based on two brachiopod species Cymathorhynchia quadriplicata and Torquirhynchia asymmetrica. The first is reported from the Middle and the Upper Bajocian sediments and has a wider palaeobiogeographical distribution, while the latter is exclusively described from the Upper Bajocian and Bathonian of the Serbian Carpatho-Balkanides. Most of the collected bivalves have a wider stratigraphie extent. Retroceramus cf. obliquus and Plagiostoma rigidula have up to now been known from the Bajocian stage. The determined macrofauna is compared with the Middle Jurassic fauna of adjacent regions of Hungary, Romania and Bulgaria, and show strong affinity to those of the northern margins of Tethys. By the end of the Bathonian, the depositional environment has changed from shallow-marine to deep-marine, suggesting a drowning of the carbonate platform. © 2011 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany.
Dragovic S.,University of Belgrade |
Jankovic-Mandic L.,Vinca Institute of Nuclear Sciences |
Dragovic R.,University of Nis |
Dordevic M.,University of Nis |
And 2 more authors.
Journal of Geochemical Exploration | Year: 2014
The survey results of concentrations of lithogenic radionuclides in surface soils from 213 locations in Serbia, their mutual concentration ratios and spatial distribution are presented. The mean concentrations of uranium, thorium and potassium in soils of 2.6mgkg-1, 9.3mgkg-1 and 1.8·104mgkg-1, respectively, were found to be similar with equivalent values reported for soils of regions with similar geological composition and geotectonic structures and also with worldwide average values. The spatial distribution of analyzed radionuclides was geostatistically interpolated using ordinary kriging. The spatial distribution maps of uranium, thorium and potassium concentrations showed their variability among different regions as a consequence of different lithological units of the investigated area. © 2013 Elsevier B.V.