Popescu I.,Polytechnic University of Bucharest |
Popescu I.,Geological Institute of Romania |
Biasioli M.,University of Turin |
Ajmone-Marsan F.,University of Turin |
Stanescu R.,Polytechnic University of Bucharest
Chemosphere | Year: 2013
Determination of total concentration of potentially toxic elements (PTEs) in soil is not a reliable tool for evaluating potential exposure risk for humans. PTE lability (EDTA, SBET and solution extraction) and chemical speciation (BCR sequential extraction) were investigated for Pb, Cd, Cu, and Zn, as well as how these could be affected by flooding in soils polluted by smelting activities.The flooding experiment was performed in pots from which soil solution was extracted at different time intervals using Rhizon Moisture Samplers. After experiments, the soil was again subjected to the previous extractions (EDTA, SBET, and BCR) in order to reveal the changes which occurred during anoxia. From the results we can conclude that PTE lability is very high and flooding caused the increase in their mobility up to 100% (for bioaccessible Pb). The experiment demonstrated that temporary reducing conditions can increase the risk of contaminants passing to other environmental compartments and the food chain. © 2012 Elsevier Ltd.
Ticleanu M.,Geological Institute of Romania
International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM | Year: 2013
Our planet is engaged simultaneously in a diversity of cosmic movements: rotation, revolution, precession. Also the galactic motion involves entire Solar System. The revolution movement around the Sun is complicated by the terrestrial orbit's variation of form. In addition, Earth seems subjected to of a radial type of movement, fact suggested by the general evolution of our planet along the time. This evolution appears to reflect pulsations of the Solar System (4,1 ma period), pulsations of our Galaxy (26 ma) or ample pulsations of Earth (~362 ma). The radial motions however suggest moments of change of phase, of sudden inversion of meaning, moments that could manifest themselves as shocks of the tectonic nature on a planetary level. These may correspond with numerous tectonic phases known through geological history of Earth. The most ample radial motion (Vail-Payton mega-cycles) would determine important planetary shocks once every 181 ma. Some of these may correspond to moments of locking of the ample contraction movements and others to moments of locking of the ample movements of expansion. Phases that correspond to moments of locking of expansion type motion seem to be associated with the important effusions of basic and ultra-basic rocks (P/T limit). Possible pulsations of our Galaxy, reflected by Raup- Sepkoski cycles, could induce moderate radial movement of Earth with obvious dynamic consequences: numerous tectonic phases repeated at an interval of about 13 ma. The locking of the expansive motion is clearly associated, in Phanerozoic, with culminations of regressive type and with moments of terrestrial fauna extinctions. The moments of locking of the contractive motion, associated with culminations of transgressive type, leads to a new series of tectonic phases and correspond to important geological limits. The Wallachian phase (orogeny), on the Pliocene/Quaternary limit, may correspond to the last phase of this type. The possible pulsations of the Solar System could induce less important but noticeable tectonic phases, repeated at a time interval at about 2,05 ma. For Neogene it's possible to link this type of motion to many more phases. Some would reflect the moments of locking of the contractive movements of the Solar System, while others would correspond to the moments of locking of the expansive movements. For Neogene time a certain type of dynamic effects (the formation of the trovants) might support such a perspective. © SGEM2013 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM.
Sabau G.,Geological Institute of Romania
Geochronometria | Year: 2012
In a single decaying system, the age determined from the exponential decay law is directly related to its linear Maclaurin approximation. This relationship can be additively extended to several decaying systems resulting in the same daughter element, by using proportionality functions, thus al-lowing an explicit formulation of the age as a function of element concentrations. The values of the binary proportionality function for the 238U- 235U-Pb system and the ternary proportionality function for the 232Th- 238U- 235U-Pb system were determined by iterations of the exponential decay formula up to 4 Ga, with a step of 10 Ma, for a set of 24 different U/Th ratios. From the iteration data, the expres-sions of the two functions and the associated coefficients were determined by polynomial regression and mathematical programing on conveniently separated time and compositional intervals. Additional time- and composition-dependent age corrections optimized by mathematical program-ming of the residuals lead to an accuracy of 0.005 Ma of the resulting age. The error propagation can be traced through all the operations defined by explicit formulas according to simple error propaga-tion rules, finally allowing the calculation of the standard error of the result. The formulas and param-eters derived can be used in a calculation spreadsheet. © 2012 Silesian University of Technology, Gliwice, Poland.
Coltoi O.,Geological Institute of Romania
75th European Association of Geoscientists and Engineers Conference and Exhibition 2013 Incorporating SPE EUROPEC 2013: Changing Frontiers | Year: 2013
Transylvanian Basin is the one of the important gas province from Central and South-East Europe. The main geological structures for entrapment of the gas accumulations in this area are the unfaulted and faulted domes. These structures are generated by the diapiric activity of the Badenian saliferous formations (named the "Salt formation"). Thus, the salt domes from the Transylvanian Basin (mostly diapiric domes) appeared as result of the Badenian salt manifestation in correlation with the tectonic movement of the adjacent blocks. For tectonic relationship between salt layer and the rest of Upper Miocene deposits have been interpreted and correlated to the regional scale more than 200 of the seismic lines. This interpretation was possible due to the information derived from about 100 wells and outcrops, beside to the existing geological maps. Concerning the Miocene tectonic evolution, most of faults or system faults have affected the all Upper Miocene and Pliocene formations. Based on this new information the identified faults are grouped by their position in relation to the margins of basin in the western, central and northern group of faults. Copyright © (2012) by the European Association of Geoscientists & Engineers All rights reserved.
Asimopolos N.S.,Geological Institute of Romania
8th Congress of the Balkan Geophysical Society, BGS 2015 | Year: 2015
The paper objective is to contribute to the clarification of the deep structure of the curvature Carpathians Vrancea by gravimetric and geodetic data interpretation in plate tectonics concept, conceptual models of the lithosphere, able to explain the increased seismicity in this area. Developing models that help explain the lithosphere geological structure of the upper crust, helping to elucidate the causes which contribute to the production of intermediate earthquakes in the Vrancea area.
Radan S.-C.,Geological Institute of Romania
Geo-Eco-Marina | Year: 2012
This tentative synopsis mainly focusses on the aspects of dating the loess - palaeosol sequences in the Romanian Plain and Dobrogea. The approach - placed in a historical framework - is defined by two characteristics. The first part is a short review of important achievements concerning the estimation or evaluation of the loess age, starting ca 120 years ago and ending in 1961. The second part continues with the loess dating history in a comprehensive table systematizing significant contributions of the last half-century. Actually, this article has been generated by another paper (under review), dedicated to a conceptual sedimentary model of the loess in the Lower Danube Basin (Jipa, submitted). The table emphasizes the interest for the loess dating during the last 50 years, and follows the chronological order of contributions. Implicitly, it is remarked the way passed through time in order to know the loess age, i.e. from the classic stratigraphy/pedostratigraphy to magnetostratigraphy, astronomically tuned ciclostratigraphy, magnetoclimatology, and up to the multi-proxy approach and optical/luminescence dating. In most of the sections, ages up to 781 ka are determined (the loess - palaeosol horizons are assigned to the Brunhes Chron of the ATNTS20004/ATNTS2012), but the synopsis includes a section from Dobrogea (analysed by the Infrared Stimulated Luminescence/IRSL dating method; Bǎlescu et al., 2003), wherefore the "estimated geological age" of 800 ka and the Marine Isotope Stage 20 are mentioned. Moreover, a recent result (Rǎdan, 2000, updated in 2012 - references therein) for a loess - palaeosol borehole profile (ca 30m thick) from the Romanian Plain points out, according to the palaeomagnetic investigation of the basal part and to the magnetic susceptibility vertical variation along the sampled borehole (40m depth), the possible identification of the Matuyama/Brunhes boundary (0.781 Ma), located at the base of the MIS 19. This subject has generated a dispute in the scientific literature on both the Chinese and the European loess. A tentative discussion on the "observed MBB" (within the loess horizon L8) and the "corrected/true MBB" (placed within the palaeosol S7) is done, by comparing our results from the Romanian Plain with data from the Chinese Loess Plateau.
Nimirciag R.,Polytechnic University of Bucharest |
Nimirciag R.,Geological Institute of Romania
Environmental Engineering and Management Journal | Year: 2012
The present study was carried out to highlight the areas where heavy metal content in the soils from Rodna mining perimeter exceeds normal limits and to attempt to reduce the concentration of free heavy metal ions by using natural Zeolite from the Dej tuff. In order to emphasize the heavy metal content and their accumulation in soil in Rodna region, 35 soil samples were collected from the upper and deeper layer (about 0-10 and 10-20 cm depth) and analyzed to determine total and free Cu, Pb and Zn concentrations. These investigations showed a heavy metal accumulation area downstream of Izvoru Rosu brook and Valea Vinului locality, where there is a large number of galleries. The aqueous solutions of soils collected from the previously mentioned area were treated with natural zeolite, with results emphasizing not only the efficiency of zeolites for heavy metal retention, but also their selectivity and behaviour, as the immobilization potential depends on initial concentration of the contaminants. Zinc sorption was much lower than lead retention, while copper was affected by the opposite process, of desorption.
Papp D.C.,Geological Institute of Romania |
Cociuba I.,Geological Institute of Romania
Geological Society Special Publication | Year: 2013
Major fluctuations in carbon-isotope composition (-2.8 to +5.4‰), as well as in oxygen-isotope composition (-10.2 to -2.1‰), are documented for Hauterivian-Albian shallow-water platform carbonate deposits in Pǎdurea Craiului (Apuseni Mountains, Romania). A composite carbon- and oxygen-isotope curve reveals the OAE1a and OAE1b as the main oceanic anoxic events (OAEs). Black shales or organic-rich levels, generally associated with such events, are poorly developed in Pǎdurea Craiului, testifying to slightly different responses to the carbon cycle perturbation between shallow- and deep-water environments. Palaeotemperatures of about 16-35 °C can be envisaged for the Late Hauterivian and Barremian in Pǎdurea Craiului, similar to those inferred from belemnite stable-isotope data from the Bersek Quarry (Gerecse Mountains, Hungary). For the Early Aptian interval, the δ13C variation pattern in Pǎdurea Craiului is similar to that documented in the Rochovica section from the Slovak Western Carpathians, developed in a deeper-water environment, although the interval of variation in Pǎdurea Craiului corresponds better to other shallow-water environment sections in the western Tethys. © The Geological Society of London 2013.
Ion A.,Geological Institute of Romania
Carpathian Journal of Earth and Environmental Sciences | Year: 2013
Radon activity concentration in outdoor air was measured using alpha radon monitors (Pylon AB- 5 portable with Continuous Passive Radon Detector). Radon in outdoor air was measured in situ, in 5 points, for each lithological unit from the study area. The radon concentration was measured at a height of 15 cm above ground level. The radon exhalation rate was continuously measured for 24 hours with a counting time of 20 minute/interval in each site. The range is considerable: from 2.6-52 Bq m-3. The release of radon from rocks and soil is controlled largely by the types of minerals in which uranium and thorium occur. In Ditrǎu Alkaline Massif, uranium (238U), thorium (232Th) and actinium (235U) are concentrated in accessory minerals such as: zircon, monazite, titanite, allanite, apatite, xenotime, rutile, thorite, bastnäsite, parisite, pyrochlore.
Papp D.C.,Geological Institute of Romania |
Cociuba I.,Geological Institute of Romania |
Lazar D.F.,Babes - Bolyai University
Applied Geochemistry | Year: 2013
Stable C and O isotope records were obtained from carbonate rocks spanning the Hauterivian to Cenomanian interval collected in several sections from the carbonate platform of Pâdurea Craiului (Apuseni Mountains, Romania). In the absence of some key biostratigraphic marker species, stable isotopes were applied as a tool for stratigraphic correlation and dating. The composite δ13C and δ18O curves for the Early Cretaceous shows variable conditions with large positive and negative excursions and provide information on past environmental changes. The Hauterivian and the Barremian limestones (Blid Formation) display lower δ13C values (-2.8‰ to +2.9‰) relative to the Aptian-Albian deposits (-2.6‰ to +5.4‰) (Ecleja, Valea Mâgurii and Vârciorog Formations). The red detrital formation (Albian-Cenomanian) is characterized by a highly variable distribution of the δ13C values (-3.5‰ to +3.9‰). Based on the similarities between the C-isotope curve established in Pâdurea Craiului and from other sections in the Tethyan and the Pacific regions, two major oceanic anoxic events characterized by δ13C positive excursions were clearly recognized. The first is the OAE1a event (Early Aptian) in the upper part of the Ecleja Formation and the Valea Mâgurii Formation. The second is the OAE1b event (Late Aptian-Albian) in the upper part of the Vârciorog Formation and in the Subpiatrâ Member. The position of the Aptian/Albian boundary is estimated to be at the upper part of the Vârciorog Formation, immediately after the beginning of the δ13C positive excursion. The δ13C data show major negative excursions during the Barremian (Blid Formation), Early Aptian (Ecleja Formation), and Late Aptian (Vârciorog Formation). The O isotope variation pattern (-10.2‰ to -2.1‰) is consistent with progressively warming temperatures during the Early Barremian followed by a cooling period. A subsequent warming period culminated in the Early Aptian. A significant cooling phase corresponds to the Late Aptian and Early Albian and the climate cooled again during the Late Albian and into the Early Cenomanian stage. The data provide a better understanding of the Early Cretaceous sedimentation cycles in Pâdurea Craiului and create a more reliable framework for regional correlations. © 2012 Elsevier Ltd.