Pub Date : 2022-11-10DOI: 10.31577/geolcarp.73.5.6
Barbara Bódai, G. Czuppon, I. Fórizs, S. Kele
: Recent fluvial tufa carbonates were investigated from the Szalajka Valley (Bükk Hungary) and Malom Valley (Balaton Uplands, Hungary) to (1) study the suitability of the published oxygen isotope-based palaeothermometers for tufa deposits, (2) find the most appropriate (closest to equilibrium) places downstream for temperature calculation. A good correlation was observed between 1000lnα and the temperature of the water from which the tufa precipitated close to the spring orifice in the Szalajka and Malom Valleys. Large differences between calculated and measured temperature values were seen in areas where the seasonal water temperature increased and decreased by several degrees during our studied period. The stable isotope composition of the measured Hungarian tufas represents intermediate values between the western and eastern parts of Europe, reflecting increasing continentality in climate from west to east. ples are reported relative to V-SMOW. The uncertainties of measurements were better than ±0.1 ‰ and ±1 ‰ for δ 18 O w and δD, respectively. Further details can be found in Czuppon et al. (2018).
{"title":"Seasonal study of calcite-water oxygen isotope fractionation at recent freshwater tufa sites in Hungary","authors":"Barbara Bódai, G. Czuppon, I. Fórizs, S. Kele","doi":"10.31577/geolcarp.73.5.6","DOIUrl":"https://doi.org/10.31577/geolcarp.73.5.6","url":null,"abstract":": Recent fluvial tufa carbonates were investigated from the Szalajka Valley (Bükk Hungary) and Malom Valley (Balaton Uplands, Hungary) to (1) study the suitability of the published oxygen isotope-based palaeothermometers for tufa deposits, (2) find the most appropriate (closest to equilibrium) places downstream for temperature calculation. A good correlation was observed between 1000lnα and the temperature of the water from which the tufa precipitated close to the spring orifice in the Szalajka and Malom Valleys. Large differences between calculated and measured temperature values were seen in areas where the seasonal water temperature increased and decreased by several degrees during our studied period. The stable isotope composition of the measured Hungarian tufas represents intermediate values between the western and eastern parts of Europe, reflecting increasing continentality in climate from west to east. ples are reported relative to V-SMOW. The uncertainties of measurements were better than ±0.1 ‰ and ±1 ‰ for δ 18 O w and δD, respectively. Further details can be found in Czuppon et al. (2018).","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44646247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: In NE Algeria and the Tunisia–Algeria border chains, detailed stratigraphic investigations across the Jurassic– Cretaceous boundary (JKB) are scarce and this important stratigraphic interval remains poorly known. This work attempts fulfilling this gap of our knowledge on the JKB successions in this area. It represents unpublished data on calpionellid zonations, based on bed-by-bed sampling, of two sections from the “Ravin Bleu” site of Batna Mountains. In the Jebel Kasserou and J. Bou Merzoug study sections, most of the standard Upper Tithonian–lowermost Valanginian calpionellid zones and subzones are first identified here. Their limits correspond to main calpionellid bioevents allowing to recognize a new Alpelliptica Subzone of the Calpionella Zone in the Lower–Middle Berriasian; subsidiary bioevents being useful to delimit six horizons in the Upper Tithonian Crassicollaria Zone and two others in the Middle Berriasian Elliptica Subzone. All these biostratigraphic units are correlated with their lateral equivalents in other Tethyan sections, mainly from Morocco, Tunisia, SE France, Spain, the Carpathian Ranges and the Balkanides. Chitinoidellid and most of the calpionellid species from Eastern Algeria are first illustrated here. In addition to their easy access and good outcrops, the continuous, complete and thick marine study successions are devoid of strong diagenetic alteration, synsedimentary features and tectonic effects. The “Ravin Bleu” site is proposed herein as a potential reference section for the JKB interval in the North Africa Maghrebian Ranges of the SW Tethys Margin.
{"title":"UPDATED CALPIONELLID ZONATION AROUND THE JURASSIC–CRETACEOUS BOUNDARY IN NE ALGERIA (“RAVIN BLEU” SITE, BATNA MOUNTAINS): A POTENTIAL REGIONAL STRATOTYPE FOR THE NORTH AFRICA MAGHREBIAN RANGES","authors":"Ichrak Cherif, Rachid Touansa, M. Boughdiri, Fouad Djaiz, Neib Bahrouni, Houaïda Sallouhi, Abdelwaheb Yahiaoui","doi":"10.31577/geolcarp.73.5.3","DOIUrl":"https://doi.org/10.31577/geolcarp.73.5.3","url":null,"abstract":": In NE Algeria and the Tunisia–Algeria border chains, detailed stratigraphic investigations across the Jurassic– Cretaceous boundary (JKB) are scarce and this important stratigraphic interval remains poorly known. This work attempts fulfilling this gap of our knowledge on the JKB successions in this area. It represents unpublished data on calpionellid zonations, based on bed-by-bed sampling, of two sections from the “Ravin Bleu” site of Batna Mountains. In the Jebel Kasserou and J. Bou Merzoug study sections, most of the standard Upper Tithonian–lowermost Valanginian calpionellid zones and subzones are first identified here. Their limits correspond to main calpionellid bioevents allowing to recognize a new Alpelliptica Subzone of the Calpionella Zone in the Lower–Middle Berriasian; subsidiary bioevents being useful to delimit six horizons in the Upper Tithonian Crassicollaria Zone and two others in the Middle Berriasian Elliptica Subzone. All these biostratigraphic units are correlated with their lateral equivalents in other Tethyan sections, mainly from Morocco, Tunisia, SE France, Spain, the Carpathian Ranges and the Balkanides. Chitinoidellid and most of the calpionellid species from Eastern Algeria are first illustrated here. In addition to their easy access and good outcrops, the continuous, complete and thick marine study successions are devoid of strong diagenetic alteration, synsedimentary features and tectonic effects. The “Ravin Bleu” site is proposed herein as a potential reference section for the JKB interval in the North Africa Maghrebian Ranges of the SW Tethys Margin.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44455139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-07DOI: 10.31577/geolcarp.73.4.4
Tzvetomila Vladinova, M. Georgieva
: Metasedimentary sequence from the westernmost Sakar Unit (Klokotnitsa Village area), Sakar–Strandja Zone, comprises a variety of lithologies with Triassic protolith age. In the study area, the Sakar Unit is affected by low-grade metamorphism in the frame of the Maritsa dextral strike-slip shear zone and separates two first-order units of the Balkan orogenic system – the Rhodope massif and the Srednogorie Zone. We present the petrography, mineral chemical data, and thermodynamic modelling of metasediments for a better understanding of the protoliths origin and metamorphic evolution. The mineral assemblages in Triassic metasediments suggest sedimentary protoliths containing quartz, clay, and carbonate minerals (sandstones, clays, and limestones). The detrital minerals (quartz, albite, orthoclase and accessory phases – zircon, monazite, apatite) reveal potential granite source provenance. The dominance of phengite–chlorite association correlates with low temperature and water-saturated conditions. The Perple_X pseudosection, combined with modelled mineral assemblages and mineral chemistry isopleths of muscovite and chlorite, correspond to metamorphism in the range 275–330 °C and 3–4 kbar. The results correspond with a chlorite geothermometer. The thermodynamic modelling corroborates the petrographic observations and proves greenschist metamorphic conditions that affected the Triassic sedimentary cover of the westernmost Sakar Unit.
{"title":"Metamorphism of the westernmost Triassic metasedimentary rocks in the Sakar unit, Sakar–Strandja zone, Bulgaria","authors":"Tzvetomila Vladinova, M. Georgieva","doi":"10.31577/geolcarp.73.4.4","DOIUrl":"https://doi.org/10.31577/geolcarp.73.4.4","url":null,"abstract":": Metasedimentary sequence from the westernmost Sakar Unit (Klokotnitsa Village area), Sakar–Strandja Zone, comprises a variety of lithologies with Triassic protolith age. In the study area, the Sakar Unit is affected by low-grade metamorphism in the frame of the Maritsa dextral strike-slip shear zone and separates two first-order units of the Balkan orogenic system – the Rhodope massif and the Srednogorie Zone. We present the petrography, mineral chemical data, and thermodynamic modelling of metasediments for a better understanding of the protoliths origin and metamorphic evolution. The mineral assemblages in Triassic metasediments suggest sedimentary protoliths containing quartz, clay, and carbonate minerals (sandstones, clays, and limestones). The detrital minerals (quartz, albite, orthoclase and accessory phases – zircon, monazite, apatite) reveal potential granite source provenance. The dominance of phengite–chlorite association correlates with low temperature and water-saturated conditions. The Perple_X pseudosection, combined with modelled mineral assemblages and mineral chemistry isopleths of muscovite and chlorite, correspond to metamorphism in the range 275–330 °C and 3–4 kbar. The results correspond with a chlorite geothermometer. The thermodynamic modelling corroborates the petrographic observations and proves greenschist metamorphic conditions that affected the Triassic sedimentary cover of the westernmost Sakar Unit.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47996638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-07DOI: 10.31577/geolcarp.73.4.1
Mária Maraszewska, I. Broska, Milan Kohút, K. Yi, P. Konečný, S. Kurylo
The geochemistry of major Low Tatra granitic types, namely Prašivá porphyritic Bt (biotite)-granodiorite and Ďumbier Bt-tonalite, indicate their derivation from initial hybrid magmas and represent a mixture among several magma pulses formed via melting of the heterogeneous lower crust. The high K calc-alkaline peraluminous character, along with high Ba, Sr + LREE contents correspond to the partial melting of K-rich mafic and the intermediate hydrated lower crustal source in equilibrium with amphibole or possibly garnet with variable involvement of metasedimentary and/or felsic metaigneous sources. The zircon isotopic age of 360.4 ± 2.7 Ma recorded from diatexite reflects the timing of hightemperature metamorphism of subducted continental crust, and thus corresponds in an initial anatectic process within the present Tatric Unit. The magmatic ages are in the largely overlapping sequence of 353 ± 2 Ma for the Ďumbier tonalite and 352 ± 3 Ma and 351.9 ± 2.9 Ma for Prašivá Aln (allanite bearing)-subtype and Mnz (monazite bearing)-subtypes, which indicate successive multiple emplacement of magma batches and natural evolution towards their more crustal character. Magmatism in the Low Tatra Mts. represents a post-collisional plutonic system related to the slab break-off mechanism described in the close Malá Fatra crystalline basement as well. Heat from mantle upwelling and volatiles from previous subduction forced the melting of the lower crust towards K-rich mafic or intermediate lithologies, as well as during the emplacement of long-lasting melting of felsic metasedimentary crustal sources. The crystalline core of the Low Tatra Mts. is another example of composite granite pluton in the Western Carpathians, which represents a product of the multiphase Late-Variscan post-collisional setting.
{"title":"The Ďumbier – Prašivá high K calc-alkaline granite suite (Low Tatra Mts., Western Carpathians): Insights into their evolution from geochemistry and geochronology","authors":"Mária Maraszewska, I. Broska, Milan Kohút, K. Yi, P. Konečný, S. Kurylo","doi":"10.31577/geolcarp.73.4.1","DOIUrl":"https://doi.org/10.31577/geolcarp.73.4.1","url":null,"abstract":"The geochemistry of major Low Tatra granitic types, namely Prašivá porphyritic Bt (biotite)-granodiorite and Ďumbier Bt-tonalite, indicate their derivation from initial hybrid magmas and represent a mixture among several magma pulses formed via melting of the heterogeneous lower crust. The high K calc-alkaline peraluminous character, along with high Ba, Sr + LREE contents correspond to the partial melting of K-rich mafic and the intermediate hydrated lower crustal source in equilibrium with amphibole or possibly garnet with variable involvement of metasedimentary and/or felsic metaigneous sources. The zircon isotopic age of 360.4 ± 2.7 Ma recorded from diatexite reflects the timing of hightemperature metamorphism of subducted continental crust, and thus corresponds in an initial anatectic process within the present Tatric Unit. The magmatic ages are in the largely overlapping sequence of 353 ± 2 Ma for the Ďumbier tonalite and 352 ± 3 Ma and 351.9 ± 2.9 Ma for Prašivá Aln (allanite bearing)-subtype and Mnz (monazite bearing)-subtypes, which indicate successive multiple emplacement of magma batches and natural evolution towards their more crustal character. Magmatism in the Low Tatra Mts. represents a post-collisional plutonic system related to the slab break-off mechanism described in the close Malá Fatra crystalline basement as well. Heat from mantle upwelling and volatiles from previous subduction forced the melting of the lower crust towards K-rich mafic or intermediate lithologies, as well as during the emplacement of long-lasting melting of felsic metasedimentary crustal sources. The crystalline core of the Low Tatra Mts. is another example of composite granite pluton in the Western Carpathians, which represents a product of the multiphase Late-Variscan post-collisional setting.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42210648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-07DOI: 10.31577/geolcarp.73.4.6
S. Georgiev, D. Dimitrova, Marianna Yossifova, Milena Vetseva, R. Ivanova
: This contribution presents the age of the detrital zircons from the coal bearing Miocene succession of the Maritsa East lignite basin. We report a new finding of thin kaolinized pyroclastic beds (tonstein) in the coal bearing succession. The analysis of the detrital age component shows sedimentary input from the basement of the proximal area. The most abundant age cluster 290–315 Ma shows that the predominant sources are the Early Permian–Late Carboni ferous intrusions in the area. The newlyrecognized tonstein beds represent the products of large, distal pyroclastic erup tions and are an important element of the sedimentary succession. They are dated at 14.31±0.30 Ma, which corresponds to the absolute age of the organic matter deposition of the productive middle lignite seam. Their source could most likely be related to the Miocene acid paroxysm ignimbrite eruptions in the Pannonian basin.
{"title":"Tephrochronology of a distal tonstein layer within the Maritsa East lignite basin, Bulgaria: Potential sources of the Miocene large explosive eruption","authors":"S. Georgiev, D. Dimitrova, Marianna Yossifova, Milena Vetseva, R. Ivanova","doi":"10.31577/geolcarp.73.4.6","DOIUrl":"https://doi.org/10.31577/geolcarp.73.4.6","url":null,"abstract":": This contribution presents the age of the detrital zircons from the coal bearing Miocene succession of the Maritsa East lignite basin. We report a new finding of thin kaolinized pyroclastic beds (tonstein) in the coal bearing succession. The analysis of the detrital age component shows sedimentary input from the basement of the proximal area. The most abundant age cluster 290–315 Ma shows that the predominant sources are the Early Permian–Late Carboni ferous intrusions in the area. The newlyrecognized tonstein beds represent the products of large, distal pyroclastic erup tions and are an important element of the sedimentary succession. They are dated at 14.31±0.30 Ma, which corresponds to the absolute age of the organic matter deposition of the productive middle lignite seam. Their source could most likely be related to the Miocene acid paroxysm ignimbrite eruptions in the Pannonian basin.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41557069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-07DOI: 10.31577/geolcarp.73.4.2
Marína Molčan Matejová, P. Gedl
: The Pieniny Klippen Belt of the Western Carpathians is built up by Jurassic to Eocene Oravic units, with the Šariš, Subpieniny, and Pieniny Unit on the top. Major emphasis was placed on the dark fine-grained clastic deposits exposed in the vicinity of the villages of Beňova Lehota and Revišné (Orava sector of the Pieniny Klippen Belt). Through investigation of palynological material, the age of dark flysch strata was determined as predominantly uppermost Toarcian to Middle Aalenian and affiliated with the Szlachtowa and/or Skrzypny formations, belonging to the Šariš Unit. The results from the dinoflagellate cysts were supplemented by a structural investigation of the Šariš Unit. The complicated tectonic evolution of the Pieniny Klippen Belt is documented by intermixing of the soft shale deposits of Jurassic and Cretaceous age and by the presence of folds and cleavages. Based on the acquired data, the D 1 event records a compression with a NE–SW direction and is represented by folds with axial-plane cleavage. The younger D 2 phase is marked by the presence of south-vergent backthrusts, resulting from the ongoing compression and subsequent tilting of the originally north-vergent nappe stack of the Oravic units.
{"title":"The Orava segment of the Pieniny Klippen Belt: Lithology, structure and stratigraphy based on the organic-walled dinoflagellate cysts (Šariš Unit)","authors":"Marína Molčan Matejová, P. Gedl","doi":"10.31577/geolcarp.73.4.2","DOIUrl":"https://doi.org/10.31577/geolcarp.73.4.2","url":null,"abstract":": The Pieniny Klippen Belt of the Western Carpathians is built up by Jurassic to Eocene Oravic units, with the Šariš, Subpieniny, and Pieniny Unit on the top. Major emphasis was placed on the dark fine-grained clastic deposits exposed in the vicinity of the villages of Beňova Lehota and Revišné (Orava sector of the Pieniny Klippen Belt). Through investigation of palynological material, the age of dark flysch strata was determined as predominantly uppermost Toarcian to Middle Aalenian and affiliated with the Szlachtowa and/or Skrzypny formations, belonging to the Šariš Unit. The results from the dinoflagellate cysts were supplemented by a structural investigation of the Šariš Unit. The complicated tectonic evolution of the Pieniny Klippen Belt is documented by intermixing of the soft shale deposits of Jurassic and Cretaceous age and by the presence of folds and cleavages. Based on the acquired data, the D 1 event records a compression with a NE–SW direction and is represented by folds with axial-plane cleavage. The younger D 2 phase is marked by the presence of south-vergent backthrusts, resulting from the ongoing compression and subsequent tilting of the originally north-vergent nappe stack of the Oravic units.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46651690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-07DOI: 10.31577/geolcarp.73.4.3
Viktória Subová, S. Rybár, Katarína Šarinová, N. Hudáčková, Michal Jamrich, Ľ. Sliva, B. Šály, I. Hlavatý
: The Transcarpathian Basin, consisting of the Prešov and Trebišov sub-basins, is situated at the border of the Western and Eastern Carpathians. Hydrocarbon exploration in this basin has been ongoing for more than 60 years and reserves of economic importance are located in the E to NE part of the basin. The Trebišov sub-basin was analysed to characterize and predict lower Badenian (Langhian) reservoir rocks. To achieve this aim, new sedimentary facies, seismic facies, petrographic and paleontological analyses were performed, combined with original total porosity and permeability measurements. Based on the planktic foraminifera and calcareous nannoplankton zonation, the lower Badenian sequence in the Trebišov sub-basin was divided into a lower and an upper interval. The presence of very well sorted sandstone layers, glauconite grains, albitization, selective alteration of tuffs into zeolites as well as the fossil assemblages reinforce the volcanic influenced marine environments. Documented sedimentary structures indicate subaqueous density flows preceded by the newly observed fluvial and deltaic facies. The total sandstone porosity measurements indicate a gradual porosity decrease with depth marked by a value of 13.21 % at the surface decreasing down to 6.41 % at ~3 km below the surface. These numbers correspond to reservoirs with low to reduced porosity. Diagenetic products such as illite, chlorite and feldspar cement together with compaction effects, and variations in the crystallinity in siliceous cement led to the modification of initial porosity. The potential lower Badenian reservoir sandstones are frequently deformed by strike-slip faults responsible for the large pull-apart basin complex (seen as horsetail structures on reflection seismic sections) forming various fault-bounded structural traps. The lower Badenian sandstones present at the top of two anti clinal structures in the central part of the basin, display very strong reflection amplitudes on newly merged 3D reflection seismic data underlining the additional exploration potential in the basin.
{"title":"Evolution of the lower Badenian depositional system in the East Slovakian Basin: Implications for reservoir rock potential","authors":"Viktória Subová, S. Rybár, Katarína Šarinová, N. Hudáčková, Michal Jamrich, Ľ. Sliva, B. Šály, I. Hlavatý","doi":"10.31577/geolcarp.73.4.3","DOIUrl":"https://doi.org/10.31577/geolcarp.73.4.3","url":null,"abstract":": The Transcarpathian Basin, consisting of the Prešov and Trebišov sub-basins, is situated at the border of the Western and Eastern Carpathians. Hydrocarbon exploration in this basin has been ongoing for more than 60 years and reserves of economic importance are located in the E to NE part of the basin. The Trebišov sub-basin was analysed to characterize and predict lower Badenian (Langhian) reservoir rocks. To achieve this aim, new sedimentary facies, seismic facies, petrographic and paleontological analyses were performed, combined with original total porosity and permeability measurements. Based on the planktic foraminifera and calcareous nannoplankton zonation, the lower Badenian sequence in the Trebišov sub-basin was divided into a lower and an upper interval. The presence of very well sorted sandstone layers, glauconite grains, albitization, selective alteration of tuffs into zeolites as well as the fossil assemblages reinforce the volcanic influenced marine environments. Documented sedimentary structures indicate subaqueous density flows preceded by the newly observed fluvial and deltaic facies. The total sandstone porosity measurements indicate a gradual porosity decrease with depth marked by a value of 13.21 % at the surface decreasing down to 6.41 % at ~3 km below the surface. These numbers correspond to reservoirs with low to reduced porosity. Diagenetic products such as illite, chlorite and feldspar cement together with compaction effects, and variations in the crystallinity in siliceous cement led to the modification of initial porosity. The potential lower Badenian reservoir sandstones are frequently deformed by strike-slip faults responsible for the large pull-apart basin complex (seen as horsetail structures on reflection seismic sections) forming various fault-bounded structural traps. The lower Badenian sandstones present at the top of two anti clinal structures in the central part of the basin, display very strong reflection amplitudes on newly merged 3D reflection seismic data underlining the additional exploration potential in the basin.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48896471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-07DOI: 10.31577/geolcarp.73.4.5
Sylvina Georgieva, R. Vassileva, Georgi Milenkov, Elitsa Stefanova
: The geochemical behaviour of major, rare, and trace elements in members of epidote-group minerals formed at different stages of magmatic and hydrothermal activity in pegmatites from the Madan ore district was studied. Accessory allanite-(Ce) and two generations of hydrothermal clinozoisite–epidote occur in hydrothermally-altered pegmatite bodies at the 820 mine level in the Petrovitsa Pb–Zn deposit. Abundant large concordant and crosscutting pegmatites (age 49.63 ± 0.94 Ma) with a thickness of more than 2 m are embedded in a high-grade metamorphic complex composed of various gneisses, amphibolites, and marbles in the area of the Petrovitsa deposit. The pegmatites consist mainly of feldspars and quartz, with plagioclases (albite–oligoclase, oligoclase–andesine, anorthite) predominating over K-feldspars. The main accessory minerals are allanite-(Ce), zircon, apatite, and an abundance of titanite. The overprinted hydrothermal mineral association is characterised by the formation of clinozoisite–epidote, adularia, chlorite, Ca-garnet, titanite, leucoxene, carbonates, hematite, and quartz. Based on petrographic observations, mineral relationships, and chemical properties, two generations of epidotes ( sensu lato ) were recognised: early epidote (Ep1) and late epidote (Ep2). Chemically, allanite-(Ce) contains high amounts of La and Th. The mineral suffered alteration due to several multiphase hydrothermal events and is partly or entirely transformed into REE-rich clinozoisite, causing depletion in REE and Th as well as enrichment of Si, Al, and Ca. The epidote 1 generation is defined chemically as clinozoisite to clinozoisite– epidote, whereas the late epidote 2 generation is clinozoisite–epidote, reaching epidote members. The REE contents in the studied epidotes from both generations are equally low with minor exceptions. The influx of later fluids percolated through and probably extracted REE from allanite and thereafter concentrated them in late-generation epidotes. This is also evidenced by some high REE contents in epidotes from both generations, formed in close proximity to allanite or titanite and/or overgrowing them, which is a sign of restricted REE transport.
{"title":"Major and trace element signature of epidote-group minerals in altered pegmatites from the Petrovitsa Pb–Zn deposit of the Madan ore region, Central Rhodopes, Bulgaria: Evidence of allanite/epidote transformation","authors":"Sylvina Georgieva, R. Vassileva, Georgi Milenkov, Elitsa Stefanova","doi":"10.31577/geolcarp.73.4.5","DOIUrl":"https://doi.org/10.31577/geolcarp.73.4.5","url":null,"abstract":": The geochemical behaviour of major, rare, and trace elements in members of epidote-group minerals formed at different stages of magmatic and hydrothermal activity in pegmatites from the Madan ore district was studied. Accessory allanite-(Ce) and two generations of hydrothermal clinozoisite–epidote occur in hydrothermally-altered pegmatite bodies at the 820 mine level in the Petrovitsa Pb–Zn deposit. Abundant large concordant and crosscutting pegmatites (age 49.63 ± 0.94 Ma) with a thickness of more than 2 m are embedded in a high-grade metamorphic complex composed of various gneisses, amphibolites, and marbles in the area of the Petrovitsa deposit. The pegmatites consist mainly of feldspars and quartz, with plagioclases (albite–oligoclase, oligoclase–andesine, anorthite) predominating over K-feldspars. The main accessory minerals are allanite-(Ce), zircon, apatite, and an abundance of titanite. The overprinted hydrothermal mineral association is characterised by the formation of clinozoisite–epidote, adularia, chlorite, Ca-garnet, titanite, leucoxene, carbonates, hematite, and quartz. Based on petrographic observations, mineral relationships, and chemical properties, two generations of epidotes ( sensu lato ) were recognised: early epidote (Ep1) and late epidote (Ep2). Chemically, allanite-(Ce) contains high amounts of La and Th. The mineral suffered alteration due to several multiphase hydrothermal events and is partly or entirely transformed into REE-rich clinozoisite, causing depletion in REE and Th as well as enrichment of Si, Al, and Ca. The epidote 1 generation is defined chemically as clinozoisite to clinozoisite– epidote, whereas the late epidote 2 generation is clinozoisite–epidote, reaching epidote members. The REE contents in the studied epidotes from both generations are equally low with minor exceptions. The influx of later fluids percolated through and probably extracted REE from allanite and thereafter concentrated them in late-generation epidotes. This is also evidenced by some high REE contents in epidotes from both generations, formed in close proximity to allanite or titanite and/or overgrowing them, which is a sign of restricted REE transport.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46373925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-26DOI: 10.31577/geolcarp.73.3.5
Tamás Csibri, Andrej Ruman, Natália Hlavatá Hudáčková, Michal Jamrich, Ľ. Sliva, Katarína Šarinová, M. Kováč
Adam Tomašových) Abstract: The cross-border correlations of the Miocene lithostratigraphic units (Slovakia, Austria) remain poorly constrained, owing to the various sources of clastic material transported into the basin and the low stratigraphic resolution of conglomerates. Therefore, this study is focused on the Lower and Middle Miocene conglomerates in the deltaic systems of the northern Vienna Basin and assesses their implications for cross-border correlations, as well as for the evolution of the Eastern Alpine – Western Carpathians junction area. Revision of lithostratigraphy is based on analyses of the Zohor-1 and Lozorno-1 wells, including the reassessment of published data to account for any refined geochronology and paleogeography. The Lower Miocene Jablonica deltaic system is formed by deposits originating in the alluvial, deltaic, and littoral environments in the basin’s northernmost tip. The conglomerates of exclusively Western Carpathian provenance pass into the deep-water marine mudstones of the Ottnangian Lužice and Karpatian Lakšáry fms. The Karpa tian conglomerates at the base of the Zohor-1 well can be correlated both with the conglomerates of the Jablonica deltaic system in the north, as well as with the conglomerates of the Gänserndorf Mb. in the south. The overlying heterolithic flood plain of the deltaic sediments from the Závod Fm. most likely form the facies continuation of the alluvial to flood plain deposits of the Schönkirchen Mb. (upper part of the Aderklaa Fm.). The Middle Miocene deposition starts with terrestrial sediments along the slopes of the Malé Karpaty Mts. dated to 15.2 Ma. Later, along with the Devínska Nová Ves fan-delta, the presence of Orbulina suturalis developed in the marginal parts of the Vienna Basin during the Early Badenian . Despite having the same structural position, it is younger than the Rothneusiedl Formation in the southern part of the Vienna Basin. The provenance of clastics reflects the source in the Central Western Carpathian units and documents the Miocene uplift of the horst structure of the Malé
Adam Tomašových）摘要：中新世岩石地层单元（斯洛伐克、奥地利）的跨界对比仍然受到很差的限制，这是由于输送到盆地中的碎屑物质来源多种多样，砾岩的地层分辨率较低。因此，本研究的重点是维也纳盆地北部三角洲系统中新世下和中新世砾岩，并评估其对跨界相关性的影响，以及对东阿尔卑斯-西喀尔巴阡山脉交界区的演变的影响。岩石地层学的修订基于对Zohor-1和Lozorno-1井的分析，包括对已公布数据的重新评估，以说明任何精细的地质年代和古地理。下中新世Jablonica三角洲系统由源自盆地最北端冲积、三角洲和滨海环境的沉积物形成。完全来自喀尔巴阡山脉西部的砾岩进入Ottnagian Lužice和Karpatian Lakšáry组的深水海洋泥岩。Zohor-1井底部的Karpa阶砾岩可以与北部Jablonica三角洲系统的砾岩以及Gänsendorf Mb的砾岩相关联。在南部。Závod组三角洲沉积物的上覆异石器时代洪泛平原很可能形成Schönkirchen-Mb冲积至洪泛平原沉积物的相延续。（Aderklaa组的上部）。中新世中期的沉积始于15.2 Ma的MaléKarpaty Mts斜坡上的陆地沉积物。后来，随着Devínska NováVes扇三角洲的出现，早巴登尼亚时期，维也纳盆地边缘地区形成了Orbulina suturalis。尽管具有相同的构造位置，但它比维也纳盆地南部的Rothneusiedl组年轻。碎屑的来源反映了喀尔巴阡山脉中西部单元的来源，并记录了马累地垒结构的中新世隆起
{"title":"Deltaic systems of the northern Vienna Basin: The lower-middle Miocene conglomerate bodies","authors":"Tamás Csibri, Andrej Ruman, Natália Hlavatá Hudáčková, Michal Jamrich, Ľ. Sliva, Katarína Šarinová, M. Kováč","doi":"10.31577/geolcarp.73.3.5","DOIUrl":"https://doi.org/10.31577/geolcarp.73.3.5","url":null,"abstract":"Adam Tomašových) Abstract: The cross-border correlations of the Miocene lithostratigraphic units (Slovakia, Austria) remain poorly constrained, owing to the various sources of clastic material transported into the basin and the low stratigraphic resolution of conglomerates. Therefore, this study is focused on the Lower and Middle Miocene conglomerates in the deltaic systems of the northern Vienna Basin and assesses their implications for cross-border correlations, as well as for the evolution of the Eastern Alpine – Western Carpathians junction area. Revision of lithostratigraphy is based on analyses of the Zohor-1 and Lozorno-1 wells, including the reassessment of published data to account for any refined geochronology and paleogeography. The Lower Miocene Jablonica deltaic system is formed by deposits originating in the alluvial, deltaic, and littoral environments in the basin’s northernmost tip. The conglomerates of exclusively Western Carpathian provenance pass into the deep-water marine mudstones of the Ottnangian Lužice and Karpatian Lakšáry fms. The Karpa tian conglomerates at the base of the Zohor-1 well can be correlated both with the conglomerates of the Jablonica deltaic system in the north, as well as with the conglomerates of the Gänserndorf Mb. in the south. The overlying heterolithic flood plain of the deltaic sediments from the Závod Fm. most likely form the facies continuation of the alluvial to flood plain deposits of the Schönkirchen Mb. (upper part of the Aderklaa Fm.). The Middle Miocene deposition starts with terrestrial sediments along the slopes of the Malé Karpaty Mts. dated to 15.2 Ma. Later, along with the Devínska Nová Ves fan-delta, the presence of Orbulina suturalis developed in the marginal parts of the Vienna Basin during the Early Badenian . Despite having the same structural position, it is younger than the Rothneusiedl Formation in the southern part of the Vienna Basin. The provenance of clastics reflects the source in the Central Western Carpathian units and documents the Miocene uplift of the horst structure of the Malé","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42982767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-26DOI: 10.31577/geolcarp.73.3.3
M. Belak, Damir Slovenec, T. Kolar-Jurkovšek, V. Garašić, Z. Pécskay, D. Tibljaš, Ivan Mišur
Igor Broska) Abstract: The low-grade metasedimentary rocks of Medvednica Mt. (Northwest Croatia) are associated with ortho-greenschists (metabasalts). The Lower to Upper Triassic age of the protolith of the low-grade metamorphic rocks belonging to the Stari Potok, Adolfovac, Tusti Breg, Bliznec, Mrzljak, and Sljeme lithostratigraphic units is determined on the basis of conodonts and field relationships. The metamorphic age of the Triassic metasedimentary rocks from the Risnjak lithostratigraphic units is assumed to be Jurassic. Petrographic and geochemical analyses of ortho-greenschists point to a tholeiite basic magmatic protolith rock having T-MORB (transitional midocean-ridge basalt) characteristics. The ortho-greenschists of the Sljeme lithostratigraphic unit underwent retrograde metamorphism and show metamorphic zoning from the epidote–amphibolite facies to the lower parts of the greenschist facies. However, the greenschists of the Tusti Breg and Bliznec units are characterized by prograde metamorphism ranging from lower to higher greenschist facies. This metamorphism is associated with Jurassic subduction (165–150 Ma) and closure of the Western Tethys. Retrograde metamorphism took place during the collision of the Adriatic and Eurasian plates in the Lower Cretaceous This study represents the new geochemical and petrological data on the Triassic protolith of the low-grade metamorphic rocks of Mt. Medvednica (NW Croatia). The aim of the paper is to determine the chronostratigraphic age of the protoliths of the studied metamorphic rocks, including the time and grade of metamorphism, as well as define the mineralogical, petrological, and geochemical characteristics of ortho-greenschists of Mt. Medvednica and elucidate the geotectonic setting of their formation. On the basis of the results, the protolithic age of the metamorphic rocks was reinterpreted, and thus metamorphism was associated with Alpine orogeny during the closure of the Western Tethys. Additionally, in order to examine the hypothesis of the single Tethyan ocean area during the Mesozoic the analysed ortho-greenschists and their protoliths from the metamorphic complex of Mt. Medvednica were compared with analogous rocks in ophiolite mélanges from the neighbouring magmatic–sedi-mentary complexes (ophiolite mélanges) of the Zagorje–Mid-Transdanubian Zone (ZMTDZ). The analysis of geochemical affinities and geological characteristics of analogous rocks from the will contribute better knowledge the during the
{"title":"Low-grade metamorphic rocks of the Tethys subduction–collision zone in the Medvednica Mt. (NW Croatia)","authors":"M. Belak, Damir Slovenec, T. Kolar-Jurkovšek, V. Garašić, Z. Pécskay, D. Tibljaš, Ivan Mišur","doi":"10.31577/geolcarp.73.3.3","DOIUrl":"https://doi.org/10.31577/geolcarp.73.3.3","url":null,"abstract":"Igor Broska) Abstract: The low-grade metasedimentary rocks of Medvednica Mt. (Northwest Croatia) are associated with ortho-greenschists (metabasalts). The Lower to Upper Triassic age of the protolith of the low-grade metamorphic rocks belonging to the Stari Potok, Adolfovac, Tusti Breg, Bliznec, Mrzljak, and Sljeme lithostratigraphic units is determined on the basis of conodonts and field relationships. The metamorphic age of the Triassic metasedimentary rocks from the Risnjak lithostratigraphic units is assumed to be Jurassic. Petrographic and geochemical analyses of ortho-greenschists point to a tholeiite basic magmatic protolith rock having T-MORB (transitional midocean-ridge basalt) characteristics. The ortho-greenschists of the Sljeme lithostratigraphic unit underwent retrograde metamorphism and show metamorphic zoning from the epidote–amphibolite facies to the lower parts of the greenschist facies. However, the greenschists of the Tusti Breg and Bliznec units are characterized by prograde metamorphism ranging from lower to higher greenschist facies. This metamorphism is associated with Jurassic subduction (165–150 Ma) and closure of the Western Tethys. Retrograde metamorphism took place during the collision of the Adriatic and Eurasian plates in the Lower Cretaceous This study represents the new geochemical and petrological data on the Triassic protolith of the low-grade metamorphic rocks of Mt. Medvednica (NW Croatia). The aim of the paper is to determine the chronostratigraphic age of the protoliths of the studied metamorphic rocks, including the time and grade of metamorphism, as well as define the mineralogical, petrological, and geochemical characteristics of ortho-greenschists of Mt. Medvednica and elucidate the geotectonic setting of their formation. On the basis of the results, the protolithic age of the metamorphic rocks was reinterpreted, and thus metamorphism was associated with Alpine orogeny during the closure of the Western Tethys. Additionally, in order to examine the hypothesis of the single Tethyan ocean area during the Mesozoic the analysed ortho-greenschists and their protoliths from the metamorphic complex of Mt. Medvednica were compared with analogous rocks in ophiolite mélanges from the neighbouring magmatic–sedi-mentary complexes (ophiolite mélanges) of the Zagorje–Mid-Transdanubian Zone (ZMTDZ). The analysis of geochemical affinities and geological characteristics of analogous rocks from the will contribute better knowledge the during the","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45118868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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