Evaporitic gypsum deposits represent an important paleoenvironmental record of the Miocene Badeni... more Evaporitic gypsum deposits represent an important paleoenvironmental record of the Miocene Badenian of the Carpathian Mountains belt. In this study, we developed a nontoxic method to concentrate calcareous microfossils from gypsum (CaSO4·2H2O), by treating the sulfate with ammonium acetate. We applied the newly developed method to gypsum collected from the Evaporitic Formation outcropping northward of Slănic-Prahova in the Eastern Carpathians. For the first time for this formation, we describe a calcareous microfossil assemblage characterized by the presence of planktonic foraminifera as well as cysts and fragments of calcareous algae.
Geological Society, London, Special Publications, 2021
A groundwater geochemistry study was carried out on 24 samples collected from different springs a... more A groundwater geochemistry study was carried out on 24 samples collected from different springs and wells situated in a plateau area at an elevation of 200 to 300 m in the Mehedinţi County, south-western Romania. The study was motivated by the fact that springs have represented the only source of potable water in the region, only recently completed by tens of meter deep well drillings. Spring distributions and geological data reveal the presence of a multi-layered system situated in the Lower Quaternary deposits. The mean δ18O and δD values of groundwater, −9.8‰ and −67.8‰, respectively, reflect the yearly weighted mean of the isotopic composition of precipitation, demonstrating locally derived recharge. The Piper ternary diagrams indicate that the dominant hydrochemical types is HCO3−-Ca+2-Mg+2 with transition toward higher SO4−2 and Mg+2 contents to the deeper aquifer. The anions vary from HCO3− with transition to no dominant- and with Cl− contents higher for the shallower aquifer. The sequence of abundance of cations is generally Ca2+>Mg+2>K+>Na+ and for anions: HCO3−>SO4−2>Cl−>NO3−>F−. Radiocarbon dating of DIC (dissolved inorganic carbon) indicates a sub recent recharge of the aquifers. The vertical and lateral variations in groundwater chemistry may vary, and are influenced by lateral lithologic variation of the Quaternary clastic deposits. This is an unpredictable quality factor when taking the decision for the drinking water drill locations.
We present new sedimentological, petrographical, palaeontological and detrital
zircon U–Pb data ... more We present new sedimentological, petrographical, palaeontological and detrital
zircon U–Pb data on late Oligocene–early Miocene sedimentary rocks of the thin-skinned thrust belt of East Carpathians. These data were acquired to reconstruct the sedimentary routing system for two compositionally different turbidite fans made of the regionally extensive Kliwa and Fusaru formations. On the eastern margin of the Moldavides foreland basin, large low-gradient river systems draining the East European Platform provided well-sorted quartz-rich sand forming deltas on wide shallow shelves and thick Kliwa submarine fans. Due to the westward subduction of a thinned continental plate, the western basin margin was characterized by short, steep-gradient routing systems where sediment transport to deep water was mainly through hyperpycnal flows. The Getic and Bucovinian nappes of the East Carpathians and the exhumed Cretaceous–Early Palaeogene orogenic wedge fed Fusaru fans with poorly sorted lithic sand. The Fusaru fans trend northwards in the foredeep basin having an elongate depocentre, interfingering and then overlapping on the distal part of the Kliwa depositional system due to the eastward advance of the Carpathian fold-and-thrust belt. A smaller sediment input is supplied by southern continental areas (i.e. Moesian Platform, North Dobrogea and potentially the Balkans). In general, the sandstone interfingering between distinct basin floor fan systems is less well documented because the facies would be similar and there are not many systems that have a distinct sediment provenance like Kliwa and Fusaru systems. This case study improves the understanding of regional palaeogeography and sedimentary routing systems and provides observations relevant here or elsewhere on the interfingering turbidite fan systems.
Geological Society London, Special Publications 507, 2020
A groundwater geochemistry study was carried out on 24 samples collected from different springs a... more A groundwater geochemistry study was carried out on 24 samples collected from different springs and wells situated in a plateau area at an elevation of 200 to 300 m in the Mehedinţi County, south-western Romania. The study was motivated by the fact that springs have represented the only source of potable water in the region, only recently completed by tens of meter deep well drillings. Spring distributions and geological data reveal the presence of a multi-layered system situated in the Lower Quaternary deposits. The mean δ18O and δD values of groundwater, −9.8‰ and −67.8‰, respectively, reflect the yearly weighted mean of the isotopic composition of precipitation, demonstrating locally derived recharge. The Piper ternary diagrams indicate that the dominant hydrochemical types is HCO3−-Ca+2-Mg+2 with transition toward higher SO4−2 and Mg+2 contents to the deeper aquifer. The anions vary from HCO3− with transition to no dominant- and with Cl− contents higher for the shallower aquifer. The sequence of abundance of cations is generally Ca2+>Mg+2>K+>Na+ and for anions: HCO3−>SO4−2>Cl−>NO3−>F−. Radiocarbon dating of DIC (dissolved inorganic carbon) indicates a sub recent recharge of the aquifers. The vertical and lateral variations in groundwater chemistry may vary, and are influenced by lateral lithologic variation of the Quaternary clastic deposits. This is an unpredictable quality factor when taking the decision for the drinking water drill locations.
Evaporitic gypsum deposits represent an important paleoenvironmental record of the Miocene Badeni... more Evaporitic gypsum deposits represent an important paleoenvironmental record of the Miocene Badenian of the Carpathian Mountains belt. In this study, we developed a nontoxic method to concentrate calcareous microfossils from gypsum (CaSO 4 ·2H 2 O), by treating the sulfate with ammonium acetate. We applied the newly developed method to gypsum collected from the Evaporitic Formation outcropping northward of Slănic-Prahova in the Eastern Carpathians. For the first time for this formation, we describe a calcareous microfossil assemblage characterized by the presence of planktonic foraminifera as well as cysts and fragments of calcareous algae.
New geochronological investigations for the Slănic Formation, correlated with previous bio-and li... more New geochronological investigations for the Slănic Formation, correlated with previous bio-and lithostratigaphical information, allow for a better succession of events for the Middle Miocene, including the absolute age of the Badenian salinity crisis in the bend sector of the Eastern Carpathians. Within the green Slănic Tuff, white tuff layers were in evidence. The main element distribution of the white and green tuffs indicates a dacitic composition, with higher SiO 2 content for the white tuff. The white tuff has a distinct mineralogical composition with quartz, plagioclase, biotite and clinoptilolite. From such a tuff layer a biotite concentrate gives a 40 Ar/ 39 Ar age of 13.7 ± 0.2 Ma. As above these tuff layers discrete levels of gypsum occur, the age documents the beginning of the restrictive circulation and formation of evaporites in this sector of Carpathians during Badenian times.
The application of similarity coefficients is helpful in comparative analysis between different f... more The application of similarity coefficients is helpful in comparative analysis between different fossil assemblages and it permits observations with regard to the degree of clustering reported to occurrence and lithofacies. Statistical and paleoecological analysis, were performed for bivalve assemblages occurring in Anina, Bucegi, Central Dobrogea, Codlea, Haghimas, Rarau, Rosia (Padurea Craiului Mountains). The binary (presence – absence) similarity coefficients used in this paper is the Jaccard, Dice and Kulczynski II coefficients. The similarity between the studied fossil assemblages was calculated and presented graphically using rectangular cladograms obtained with the Free Tree Software
Formation and evolution of back-arc basins is a direct response of orogenic evolution, predating ... more Formation and evolution of back-arc basins is a direct response of orogenic evolution, predating or coeval with the main phase of collision. Despite the overall regional convergent regime, the local deformation in the backarc reflects large scale subsidence linked or not with extensional deformation and associated thermal events. The Pannonian-Carpathian system allows testing models for basin formation and subsequent deformation, for ongoing orogeny and continental collision. This system comprises some of the best documented sedimentary basins in the world, located within the Alpine orogenic belt, at the transition between the western European lithosphere and the East European Craton. A crucial element of the dynamics of lithospheric deformation is the mechanics of coupling the Miocene back-arc deformation in the Pannonian basin, with continental collision and foreland basin evolution along the Carpathian arc. One of the key areas of the Pannonian basin evolution in terms of basin f...
The litho- and biostratigraphical investigations, focused on the Lower Cretaceous deposits from t... more The litho- and biostratigraphical investigations, focused on the Lower Cretaceous deposits from the Bucegi Mountain area, allow the identification of significant palaeoenvironmental changes. Based on the calpionellid, foraminiferal and calcareous nannofossil content, the age of the studied deposits was assigned to the Late Berriasian-Late Valanginian interval. The calcareous nannofloral fluctuations in diversity and abundance identified in the study area of the Southern Carpathians indicate oligotrophic conditions in the late Berriasian-earliest Valanginian, replaced by an eutrophic palaeoenvironment within the late Early Valanginian (including also the Early/Late Valanginian boundary), and by a mesotrophic setting in the Late Valanginian.
In previous papers dealing with the Middle Jurassic deposits that outcrop along the western flank... more In previous papers dealing with the Middle Jurassic deposits that outcrop along the western flank of Bucegi Mountains, the species Sphaeroidothyris sphaeroidalis (J. de C. SOWERBY) is was frequently cited in the area of the Vama Strunga Pass. Review of the previous literature and of the personal or other collections from the paleontological collection of the Laboratory of Palaeontology, University of Bucharest, suggests that this species could not be confidently recorded from the Vama Strunga area. During detailed field and laboratory work it became evident that the genus Sphaeroidothyris appears in the Middle Jurassic fossiliferous deposits in only one, previously unknown fossil site. This site occurs in the northern end of the Bucegi Mountains, between the Gaura Valley and the “La Politzie” Pass. The brachipod species diversity of this bed is lower than that of similar beds from Vama Strunga. In the newly discovered site, the genus Sphaeroidothyris is represented by the new specie...
Detailed lithostratigraphic data from a borehole in the Abrămuţ Basin, located in the northwester... more Detailed lithostratigraphic data from a borehole in the Abrămuţ Basin, located in the northwestern part of Romania, has revealed the presence of turbiditic deposits containing several layers with tuff/tuffaceous materials in the lower Badenian. The age of these deposits is determined by the presence of the foraminifera Praeorbulina glomerosa and Orbulina suturalis. Detailed quantitative and qualitative X-ray diffraction data (XRD) on 10 different tuff layers situated at depths between 2450 and 2640 m show a mineralogical association comprising analcime, quartz, volcanic glass, smectite, mica, calcite, K-feldspar, glass and minor quantity of chlorite and albite. The presence of analcime suggests that the albite isograd for the interval studied has been never reached and the maximum temperatures have been lower than c. 125°C since the early Badenian
Evaporitic gypsum deposits represent an important paleoenvironmental record of the Miocene Badeni... more Evaporitic gypsum deposits represent an important paleoenvironmental record of the Miocene Badenian of the Carpathian Mountains belt. In this study, we developed a nontoxic method to concentrate calcareous microfossils from gypsum (CaSO4·2H2O), by treating the sulfate with ammonium acetate. We applied the newly developed method to gypsum collected from the Evaporitic Formation outcropping northward of Slănic-Prahova in the Eastern Carpathians. For the first time for this formation, we describe a calcareous microfossil assemblage characterized by the presence of planktonic foraminifera as well as cysts and fragments of calcareous algae.
Geological Society, London, Special Publications, 2021
A groundwater geochemistry study was carried out on 24 samples collected from different springs a... more A groundwater geochemistry study was carried out on 24 samples collected from different springs and wells situated in a plateau area at an elevation of 200 to 300 m in the Mehedinţi County, south-western Romania. The study was motivated by the fact that springs have represented the only source of potable water in the region, only recently completed by tens of meter deep well drillings. Spring distributions and geological data reveal the presence of a multi-layered system situated in the Lower Quaternary deposits. The mean δ18O and δD values of groundwater, −9.8‰ and −67.8‰, respectively, reflect the yearly weighted mean of the isotopic composition of precipitation, demonstrating locally derived recharge. The Piper ternary diagrams indicate that the dominant hydrochemical types is HCO3−-Ca+2-Mg+2 with transition toward higher SO4−2 and Mg+2 contents to the deeper aquifer. The anions vary from HCO3− with transition to no dominant- and with Cl− contents higher for the shallower aquifer. The sequence of abundance of cations is generally Ca2+>Mg+2>K+>Na+ and for anions: HCO3−>SO4−2>Cl−>NO3−>F−. Radiocarbon dating of DIC (dissolved inorganic carbon) indicates a sub recent recharge of the aquifers. The vertical and lateral variations in groundwater chemistry may vary, and are influenced by lateral lithologic variation of the Quaternary clastic deposits. This is an unpredictable quality factor when taking the decision for the drinking water drill locations.
We present new sedimentological, petrographical, palaeontological and detrital
zircon U–Pb data ... more We present new sedimentological, petrographical, palaeontological and detrital
zircon U–Pb data on late Oligocene–early Miocene sedimentary rocks of the thin-skinned thrust belt of East Carpathians. These data were acquired to reconstruct the sedimentary routing system for two compositionally different turbidite fans made of the regionally extensive Kliwa and Fusaru formations. On the eastern margin of the Moldavides foreland basin, large low-gradient river systems draining the East European Platform provided well-sorted quartz-rich sand forming deltas on wide shallow shelves and thick Kliwa submarine fans. Due to the westward subduction of a thinned continental plate, the western basin margin was characterized by short, steep-gradient routing systems where sediment transport to deep water was mainly through hyperpycnal flows. The Getic and Bucovinian nappes of the East Carpathians and the exhumed Cretaceous–Early Palaeogene orogenic wedge fed Fusaru fans with poorly sorted lithic sand. The Fusaru fans trend northwards in the foredeep basin having an elongate depocentre, interfingering and then overlapping on the distal part of the Kliwa depositional system due to the eastward advance of the Carpathian fold-and-thrust belt. A smaller sediment input is supplied by southern continental areas (i.e. Moesian Platform, North Dobrogea and potentially the Balkans). In general, the sandstone interfingering between distinct basin floor fan systems is less well documented because the facies would be similar and there are not many systems that have a distinct sediment provenance like Kliwa and Fusaru systems. This case study improves the understanding of regional palaeogeography and sedimentary routing systems and provides observations relevant here or elsewhere on the interfingering turbidite fan systems.
Geological Society London, Special Publications 507, 2020
A groundwater geochemistry study was carried out on 24 samples collected from different springs a... more A groundwater geochemistry study was carried out on 24 samples collected from different springs and wells situated in a plateau area at an elevation of 200 to 300 m in the Mehedinţi County, south-western Romania. The study was motivated by the fact that springs have represented the only source of potable water in the region, only recently completed by tens of meter deep well drillings. Spring distributions and geological data reveal the presence of a multi-layered system situated in the Lower Quaternary deposits. The mean δ18O and δD values of groundwater, −9.8‰ and −67.8‰, respectively, reflect the yearly weighted mean of the isotopic composition of precipitation, demonstrating locally derived recharge. The Piper ternary diagrams indicate that the dominant hydrochemical types is HCO3−-Ca+2-Mg+2 with transition toward higher SO4−2 and Mg+2 contents to the deeper aquifer. The anions vary from HCO3− with transition to no dominant- and with Cl− contents higher for the shallower aquifer. The sequence of abundance of cations is generally Ca2+>Mg+2>K+>Na+ and for anions: HCO3−>SO4−2>Cl−>NO3−>F−. Radiocarbon dating of DIC (dissolved inorganic carbon) indicates a sub recent recharge of the aquifers. The vertical and lateral variations in groundwater chemistry may vary, and are influenced by lateral lithologic variation of the Quaternary clastic deposits. This is an unpredictable quality factor when taking the decision for the drinking water drill locations.
Evaporitic gypsum deposits represent an important paleoenvironmental record of the Miocene Badeni... more Evaporitic gypsum deposits represent an important paleoenvironmental record of the Miocene Badenian of the Carpathian Mountains belt. In this study, we developed a nontoxic method to concentrate calcareous microfossils from gypsum (CaSO 4 ·2H 2 O), by treating the sulfate with ammonium acetate. We applied the newly developed method to gypsum collected from the Evaporitic Formation outcropping northward of Slănic-Prahova in the Eastern Carpathians. For the first time for this formation, we describe a calcareous microfossil assemblage characterized by the presence of planktonic foraminifera as well as cysts and fragments of calcareous algae.
New geochronological investigations for the Slănic Formation, correlated with previous bio-and li... more New geochronological investigations for the Slănic Formation, correlated with previous bio-and lithostratigaphical information, allow for a better succession of events for the Middle Miocene, including the absolute age of the Badenian salinity crisis in the bend sector of the Eastern Carpathians. Within the green Slănic Tuff, white tuff layers were in evidence. The main element distribution of the white and green tuffs indicates a dacitic composition, with higher SiO 2 content for the white tuff. The white tuff has a distinct mineralogical composition with quartz, plagioclase, biotite and clinoptilolite. From such a tuff layer a biotite concentrate gives a 40 Ar/ 39 Ar age of 13.7 ± 0.2 Ma. As above these tuff layers discrete levels of gypsum occur, the age documents the beginning of the restrictive circulation and formation of evaporites in this sector of Carpathians during Badenian times.
The application of similarity coefficients is helpful in comparative analysis between different f... more The application of similarity coefficients is helpful in comparative analysis between different fossil assemblages and it permits observations with regard to the degree of clustering reported to occurrence and lithofacies. Statistical and paleoecological analysis, were performed for bivalve assemblages occurring in Anina, Bucegi, Central Dobrogea, Codlea, Haghimas, Rarau, Rosia (Padurea Craiului Mountains). The binary (presence – absence) similarity coefficients used in this paper is the Jaccard, Dice and Kulczynski II coefficients. The similarity between the studied fossil assemblages was calculated and presented graphically using rectangular cladograms obtained with the Free Tree Software
Formation and evolution of back-arc basins is a direct response of orogenic evolution, predating ... more Formation and evolution of back-arc basins is a direct response of orogenic evolution, predating or coeval with the main phase of collision. Despite the overall regional convergent regime, the local deformation in the backarc reflects large scale subsidence linked or not with extensional deformation and associated thermal events. The Pannonian-Carpathian system allows testing models for basin formation and subsequent deformation, for ongoing orogeny and continental collision. This system comprises some of the best documented sedimentary basins in the world, located within the Alpine orogenic belt, at the transition between the western European lithosphere and the East European Craton. A crucial element of the dynamics of lithospheric deformation is the mechanics of coupling the Miocene back-arc deformation in the Pannonian basin, with continental collision and foreland basin evolution along the Carpathian arc. One of the key areas of the Pannonian basin evolution in terms of basin f...
The litho- and biostratigraphical investigations, focused on the Lower Cretaceous deposits from t... more The litho- and biostratigraphical investigations, focused on the Lower Cretaceous deposits from the Bucegi Mountain area, allow the identification of significant palaeoenvironmental changes. Based on the calpionellid, foraminiferal and calcareous nannofossil content, the age of the studied deposits was assigned to the Late Berriasian-Late Valanginian interval. The calcareous nannofloral fluctuations in diversity and abundance identified in the study area of the Southern Carpathians indicate oligotrophic conditions in the late Berriasian-earliest Valanginian, replaced by an eutrophic palaeoenvironment within the late Early Valanginian (including also the Early/Late Valanginian boundary), and by a mesotrophic setting in the Late Valanginian.
In previous papers dealing with the Middle Jurassic deposits that outcrop along the western flank... more In previous papers dealing with the Middle Jurassic deposits that outcrop along the western flank of Bucegi Mountains, the species Sphaeroidothyris sphaeroidalis (J. de C. SOWERBY) is was frequently cited in the area of the Vama Strunga Pass. Review of the previous literature and of the personal or other collections from the paleontological collection of the Laboratory of Palaeontology, University of Bucharest, suggests that this species could not be confidently recorded from the Vama Strunga area. During detailed field and laboratory work it became evident that the genus Sphaeroidothyris appears in the Middle Jurassic fossiliferous deposits in only one, previously unknown fossil site. This site occurs in the northern end of the Bucegi Mountains, between the Gaura Valley and the “La Politzie” Pass. The brachipod species diversity of this bed is lower than that of similar beds from Vama Strunga. In the newly discovered site, the genus Sphaeroidothyris is represented by the new specie...
Detailed lithostratigraphic data from a borehole in the Abrămuţ Basin, located in the northwester... more Detailed lithostratigraphic data from a borehole in the Abrămuţ Basin, located in the northwestern part of Romania, has revealed the presence of turbiditic deposits containing several layers with tuff/tuffaceous materials in the lower Badenian. The age of these deposits is determined by the presence of the foraminifera Praeorbulina glomerosa and Orbulina suturalis. Detailed quantitative and qualitative X-ray diffraction data (XRD) on 10 different tuff layers situated at depths between 2450 and 2640 m show a mineralogical association comprising analcime, quartz, volcanic glass, smectite, mica, calcite, K-feldspar, glass and minor quantity of chlorite and albite. The presence of analcime suggests that the albite isograd for the interval studied has been never reached and the maximum temperatures have been lower than c. 125°C since the early Badenian
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Papers by Victor Barbu
zircon U–Pb data on late Oligocene–early Miocene sedimentary rocks of the thin-skinned thrust belt of East Carpathians. These data were acquired to reconstruct the sedimentary routing system for two compositionally different turbidite fans made of the regionally extensive Kliwa and Fusaru formations. On the eastern margin of the Moldavides foreland basin, large low-gradient river systems draining the East European Platform provided well-sorted quartz-rich sand forming deltas on wide shallow shelves and thick Kliwa submarine fans. Due to the westward subduction of a thinned continental plate, the western basin margin was characterized by short, steep-gradient routing systems where sediment transport to deep water was mainly through hyperpycnal flows. The Getic and Bucovinian nappes of the East Carpathians and the exhumed Cretaceous–Early Palaeogene orogenic wedge fed Fusaru fans with poorly sorted lithic sand. The Fusaru fans trend northwards in the foredeep basin having an elongate depocentre, interfingering and then overlapping on the distal part of the Kliwa depositional system due to the eastward advance of the Carpathian fold-and-thrust belt. A smaller sediment input is supplied by southern continental areas (i.e. Moesian Platform, North Dobrogea and potentially the Balkans). In general, the sandstone interfingering between distinct basin floor fan systems is less well documented because the facies would be similar and there are not many systems that have a distinct sediment provenance like Kliwa and Fusaru systems. This case study improves the understanding of regional palaeogeography and sedimentary routing systems and provides observations relevant here or elsewhere on the interfingering turbidite fan systems.
zircon U–Pb data on late Oligocene–early Miocene sedimentary rocks of the thin-skinned thrust belt of East Carpathians. These data were acquired to reconstruct the sedimentary routing system for two compositionally different turbidite fans made of the regionally extensive Kliwa and Fusaru formations. On the eastern margin of the Moldavides foreland basin, large low-gradient river systems draining the East European Platform provided well-sorted quartz-rich sand forming deltas on wide shallow shelves and thick Kliwa submarine fans. Due to the westward subduction of a thinned continental plate, the western basin margin was characterized by short, steep-gradient routing systems where sediment transport to deep water was mainly through hyperpycnal flows. The Getic and Bucovinian nappes of the East Carpathians and the exhumed Cretaceous–Early Palaeogene orogenic wedge fed Fusaru fans with poorly sorted lithic sand. The Fusaru fans trend northwards in the foredeep basin having an elongate depocentre, interfingering and then overlapping on the distal part of the Kliwa depositional system due to the eastward advance of the Carpathian fold-and-thrust belt. A smaller sediment input is supplied by southern continental areas (i.e. Moesian Platform, North Dobrogea and potentially the Balkans). In general, the sandstone interfingering between distinct basin floor fan systems is less well documented because the facies would be similar and there are not many systems that have a distinct sediment provenance like Kliwa and Fusaru systems. This case study improves the understanding of regional palaeogeography and sedimentary routing systems and provides observations relevant here or elsewhere on the interfingering turbidite fan systems.