Pub Date : 2021-03-02DOI: 10.31577/GEOLCARP.72.1.4
H. Gebhardt
The Waschberg–Ždánice Unit links the Alpine and Carpathian orogens. Its complex structural and sedimentary structures lack a modern interpretation, particularly in the Austrian part. In recent years, the southern end of the Waschberg–Ždánice Unit has been geologically mapped in detail. Nine large occurrences (km-size) of the Waschberg Limestone, particularly at Waschberg, Michelberg, Praunsberg, and at some unnamed places continue into and strike in line with the widespread olistostromes. They are consequently interpreted as giant-olistoliths and represent products of submarine mass transport processes contemporaneous with the adjacent olistostromes. Signs for large-scale imbricate structures (repetitive sequences) or interpretation as tectonic klippen were not found. Based on the detailed geological mapping, some previously unknown structural elements are introduced, such as Haselbach Wedge and ”crunch-zone”. The Waschberg Limestone itself is an allochthonous mixed sediment (high density debrites and turbidites) that contains shallow water benthic (e.g., Nummulites) and deep-water planktic foraminifera of different age. Formation and final deposition of the Waschberg Limestone included sedimentation of Ypresian larger foraminifera and other biogenic grains in an Ypresian/basal Lutetian basin, detachment and transport towards the north-west, mixture with crystalline basement fragments and Flysch components in an Egerian or basal Eggenburgian foredeep, exposure on unstable slopes of the thrust front, and finally mobilization and basinward transport of olistostromes and Waschberg Limestone giant olistoliths during the Eggenburgian. The formation of olistostromes and giant-olistoliths may be indicative for the increased velocity or higher intensity of the thrusting processes during the early Miocene.
{"title":"Lower Miocene olistostromes and giant-olistoliths: A new interpretation of the Eocene Waschberg Limestone occurrences and consequences for the structural composition of the southern Waschberg–Ždánice Unit in Lower Austria","authors":"H. Gebhardt","doi":"10.31577/GEOLCARP.72.1.4","DOIUrl":"https://doi.org/10.31577/GEOLCARP.72.1.4","url":null,"abstract":"The Waschberg–Ždánice Unit links the Alpine and Carpathian orogens. Its complex structural and sedimentary structures lack a modern interpretation, particularly in the Austrian part. In recent years, the southern end of the Waschberg–Ždánice Unit has been geologically mapped in detail. Nine large occurrences (km-size) of the Waschberg Limestone, particularly at Waschberg, Michelberg, Praunsberg, and at some unnamed places continue into and strike in line with the widespread olistostromes. They are consequently interpreted as giant-olistoliths and represent products of submarine mass transport processes contemporaneous with the adjacent olistostromes. Signs for large-scale imbricate structures (repetitive sequences) or interpretation as tectonic klippen were not found. Based on the detailed geological mapping, some previously unknown structural elements are introduced, such as Haselbach Wedge and ”crunch-zone”. The Waschberg Limestone itself is an allochthonous mixed sediment (high density debrites and turbidites) that contains shallow water benthic (e.g., Nummulites) and deep-water planktic foraminifera of different age. Formation and final deposition of the Waschberg Limestone included sedimentation of Ypresian larger foraminifera and other biogenic grains in an Ypresian/basal Lutetian basin, detachment and transport towards the north-west, mixture with crystalline basement fragments and Flysch components in an Egerian or basal Eggenburgian foredeep, exposure on unstable slopes of the thrust front, and finally mobilization and basinward transport of olistostromes and Waschberg Limestone giant olistoliths during the Eggenburgian. The formation of olistostromes and giant-olistoliths may be indicative for the increased velocity or higher intensity of the thrusting processes during the early Miocene.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47664525","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 : 2021-03-02DOI: 10.31577/GEOLCARP.72.1.2
Bojan Kostić, Danica Srećković-Batoćanin, P. Filipov, P. Tančić, K. Sokol
This paper presents LA-ICP-MS data for garnets from the Rudnik skarn deposit (Serbia), which range from Grs45–58Adr40–52Alm2–3 in the core and Adr70–97Grs2–29Sps1 in the rim displaying anisotropy and zoning. In spite of wide compositional variations the garnets near the end-member of andradite (Adr > 90) are generally isotropic. Fe-rich rims exhibit LREE depletion and flat HREE pattern with weak negative Eu anomaly, including higher As and W contents. On the other side, the Fe-poorer core shows flat REE pattern without any significant enrichment or depletion of REE, except higher amounts of trace elements, such as U, Th and Zr. Presence of sulphide minerals indicates reduction conditions and Eu divalent state. Different REE behaviour is conditioned by Eu2+ in reduction conditions. The observed variations in optical features and garnet chemistry are the results of their two-stage evolution. The first stage and period of garnet growth is probably buffered by mineral dissolution and reactions in the country rock. The second stage is related to hydrothermal activity when W and Fe were brought into the system probably by a boiling process in the volcanic event in the late Oligocene 23.9 Ma.
{"title":"Anisotropic grossular–andradite garnets: Evidence of two stage skarn evolution from Rudnik, Central Serbia","authors":"Bojan Kostić, Danica Srećković-Batoćanin, P. Filipov, P. Tančić, K. Sokol","doi":"10.31577/GEOLCARP.72.1.2","DOIUrl":"https://doi.org/10.31577/GEOLCARP.72.1.2","url":null,"abstract":"This paper presents LA-ICP-MS data for garnets from the Rudnik skarn deposit (Serbia), which range from Grs45–58Adr40–52Alm2–3 in the core and Adr70–97Grs2–29Sps1 in the rim displaying anisotropy and zoning. In spite of wide compositional variations the garnets near the end-member of andradite (Adr > 90) are generally isotropic. Fe-rich rims exhibit LREE depletion and flat HREE pattern with weak negative Eu anomaly, including higher As and W contents. On the other side, the Fe-poorer core shows flat REE pattern without any significant enrichment or depletion of REE, except higher amounts of trace elements, such as U, Th and Zr. Presence of sulphide minerals indicates reduction conditions and Eu divalent state. Different REE behaviour is conditioned by Eu2+ in reduction conditions. The observed variations in optical features and garnet chemistry are the results of their two-stage evolution. The first stage and period of garnet growth is probably buffered by mineral dissolution and reactions in the country rock. The second stage is related to hydrothermal activity when W and Fe were brought into the system probably by a boiling process in the volcanic event in the late Oligocene 23.9 Ma.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44246370","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 : 2021-01-15DOI: 10.31577/GEOLCARP.71.6.5
S. Neuhuber, Lukas Plan, S. Gier, E. Hintersberger, J. Lachner, D. Scholz, C. Lüthgens, S. Braumann, Fabian Bodenlenz, K. Voit, M. Fiebig
The paleoenvironmental and tectonic history at the southwestern end of the Malé Karpaty Mountains was reconstructed using sediment analysis, mineralogy, and dating. Numerical ages using 26Al/10Be burial age dating, 230Th/U ages and luminescence age dating are combined to infer the Pliocene and Pleistocene development of the Hainburg Hills region. This study investigates sediments from two caves separated by a height difference of 92 m as well as aeolian cover sands from a fissure. The cave deposits are very unlike as one is a carbonate precipitate and the other sediment infill, but both preserve information on the uplift/incision at the Alpine-Carpathian border. Emplacement of coarsegrained fluvial deposits from the upper cave was dated to 4.1–4.6 Ma using terrestrial cosmogenic 26Al and 10Be in selected quartz cobbles. Calcite precipitates from the lower cave were 230Th/U dated on three morphologically slightly different cave rafts. Ages calculated from pristine calcite are least prone to alteration and give a time of formation at ~0.31–0.34 Ma. Vertical offset rates calculated from ages and positions above the recent streambed of the Danube vary between 36–42 m/Ma for the higher position and 162 m/Ma at maximum for the lower cave and point to increased uplift/incision that has been described from other areas in the Eastern Alps and the Pannonian Basin System. Deposition of aeolian sand cover was constrained to 13.6 –15.6 ka (pIRIR225 signal) and the presence of sand as opposed to its transport/erosion suggests a change in wind velocities at the Hainburg Gate. This can possibly be correlated to the termination of a cold phase with decreasing continentality accompanied by decreasing atmospheric pressure gradients. Minerals such as hematite and smectite as well as traces of poorly crystallized iron oxides found in the matrix of the upper (older) cave, were formed during warm and humid climate conditions facilitating lateritic soil formation. This is a remnant from the late Miocene or Early Pliocene soil that formed in a subtropical climate.
{"title":"Numerical age dating of cave sediments to quantify vertical movement at the Alpine-Carpathian transition in the Plio- and Pleistocene","authors":"S. Neuhuber, Lukas Plan, S. Gier, E. Hintersberger, J. Lachner, D. Scholz, C. Lüthgens, S. Braumann, Fabian Bodenlenz, K. Voit, M. Fiebig","doi":"10.31577/GEOLCARP.71.6.5","DOIUrl":"https://doi.org/10.31577/GEOLCARP.71.6.5","url":null,"abstract":"The paleoenvironmental and tectonic history at the southwestern end of the Malé Karpaty Mountains was reconstructed using sediment analysis, mineralogy, and dating. Numerical ages using 26Al/10Be burial age dating, 230Th/U ages and luminescence age dating are combined to infer the Pliocene and Pleistocene development of the Hainburg Hills region. This study investigates sediments from two caves separated by a height difference of 92 m as well as aeolian cover sands from a fissure. The cave deposits are very unlike as one is a carbonate precipitate and the other sediment infill, but both preserve information on the uplift/incision at the Alpine-Carpathian border. Emplacement of coarsegrained fluvial deposits from the upper cave was dated to 4.1–4.6 Ma using terrestrial cosmogenic 26Al and 10Be in selected quartz cobbles. Calcite precipitates from the lower cave were 230Th/U dated on three morphologically slightly different cave rafts. Ages calculated from pristine calcite are least prone to alteration and give a time of formation at ~0.31–0.34 Ma. Vertical offset rates calculated from ages and positions above the recent streambed of the Danube vary between 36–42 m/Ma for the higher position and 162 m/Ma at maximum for the lower cave and point to increased uplift/incision that has been described from other areas in the Eastern Alps and the Pannonian Basin System. Deposition of aeolian sand cover was constrained to 13.6 –15.6 ka (pIRIR225 signal) and the presence of sand as opposed to its transport/erosion suggests a change in wind velocities at the Hainburg Gate. This can possibly be correlated to the termination of a cold phase with decreasing continentality accompanied by decreasing atmospheric pressure gradients. Minerals such as hematite and smectite as well as traces of poorly crystallized iron oxides found in the matrix of the upper (older) cave, were formed during warm and humid climate conditions facilitating lateritic soil formation. This is a remnant from the late Miocene or Early Pliocene soil that formed in a subtropical climate.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45576338","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 : 2021-01-15DOI: 10.31577/GEOLCARP.71.6.2
A. Šmuc, B. Rožič, T. Verbovšek
We investigate calciturbidite cyclicity using statistical method based on time-series analysis (Fourier analysis) of bed thickness patterns. This method was applied to four members of the Jurassic calciturbidite-dominated Travnik Formation of the Bovec Trough outcropping in three adjacent and correlated sections. Our study has shown that the Fourier analysis of calciturbidite bed thicknesses is not successful for reconstruction of cyclicity in erosional upper slope depositional environments (Member 3). On the contrary, the method shows meaningful results for lower slope and distal basin floor depositional setting (Members 1, 2, 4). Here we detected variability of cyclicity in the same time frame of deposition and also subtle lateral variation of the stacking pattern between different sections. Each section contains regional lowfrequency cycles common to all sections, and superimposed specific “local” high-frequency cycles. Tectonic factors have an influence on the low frequency, and other factors, such as the local topography, climate, different position on a depositional lobe or magnitude of the turbidite event, can force the high-frequency cycles. We calculated nine cycles for Bajocian and Bathonian (Members 1 and 2), and also nine cycles from Early Callovian to Middle/Late Oxfordian (Member 4). Due to the erosional nature of the Member 3 (Bathonian to Early Callovian) sedimentary environment, reliable comparison to Jurassic sea-level variations was not possible.
{"title":"Cyclicity of Middle Jurassic calciturbidites of the Travnik Formation, Bovec Basin, NW Slovenia","authors":"A. Šmuc, B. Rožič, T. Verbovšek","doi":"10.31577/GEOLCARP.71.6.2","DOIUrl":"https://doi.org/10.31577/GEOLCARP.71.6.2","url":null,"abstract":"We investigate calciturbidite cyclicity using statistical method based on time-series analysis (Fourier analysis) of bed thickness patterns. This method was applied to four members of the Jurassic calciturbidite-dominated Travnik Formation of the Bovec Trough outcropping in three adjacent and correlated sections. Our study has shown that the Fourier analysis of calciturbidite bed thicknesses is not successful for reconstruction of cyclicity in erosional upper slope depositional environments (Member 3). On the contrary, the method shows meaningful results for lower slope and distal basin floor depositional setting (Members 1, 2, 4). Here we detected variability of cyclicity in the same time frame of deposition and also subtle lateral variation of the stacking pattern between different sections. Each section contains regional lowfrequency cycles common to all sections, and superimposed specific “local” high-frequency cycles. Tectonic factors have an influence on the low frequency, and other factors, such as the local topography, climate, different position on a depositional lobe or magnitude of the turbidite event, can force the high-frequency cycles. We calculated nine cycles for Bajocian and Bathonian (Members 1 and 2), and also nine cycles from Early Callovian to Middle/Late Oxfordian (Member 4). Due to the erosional nature of the Member 3 (Bathonian to Early Callovian) sedimentary environment, reliable comparison to Jurassic sea-level variations was not possible.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42094291","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 : 2021-01-15DOI: 10.31577/GEOLCARP.71.6.3
William A.P. Wimpledon, V. Bakhmutov, E. Halásová, A. Svobodová, D. Reháková, C. Frau, L. Bulot
Please note, that this paper will undergo editing and resulting proof yet. So the changes and errors may be discovered which could affect the content before it is published in its final form.
请注意，这篇论文将经过编辑和最终的校对。因此，在最终出版之前，可能会发现影响内容的更改和错误。
{"title":"Comments on the geology of the Crimean Peninsula and a reply to a recent publication on the Theodosia area by Arkadiev et al. (2019): “The calcareous nannofossils and magnetostratigraphic results from the Upper Tithonian–Berriasian of Feodosiya region (Eastern Crimea)”","authors":"William A.P. Wimpledon, V. Bakhmutov, E. Halásová, A. Svobodová, D. Reháková, C. Frau, L. Bulot","doi":"10.31577/GEOLCARP.71.6.3","DOIUrl":"https://doi.org/10.31577/GEOLCARP.71.6.3","url":null,"abstract":"Please note, that this paper will undergo editing and resulting proof yet. So the changes and errors may be discovered which could affect the content before it is published in its final form.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43338958","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}
{"title":"Geodynamic interpretation of the Late Cretaceous syn-depositional magmatism in central Serbia: Inferences from biostratigraphic and petrographical investigations","authors":"M. Toljić, B. Glavaš-Trbić, U. Stojadinovic, Nemanja Krstekanić, Danica Srećković-Batoćanin","doi":"10.31577/GEOLCARP.71.6.4","DOIUrl":"https://doi.org/10.31577/GEOLCARP.71.6.4","url":null,"abstract":"1University of Belgrade, Faculty of Mining and Geology, Djušina 7, 11000 Belgrade, Serbia; marinko.toljic@rgf.bg.ac.rs, uros.stojadinovic@rgf.bg.ac.rs, nemanja.krstekanic@rgf.bg.ac.rs, danica.sreckovic@rgf.bg.ac.rs 2Geological Survey of Serbia, Rovinjska 12, Belgrade, Serbia; bojan.glavas@gzs.gov.rs 3Utrecht University, Faculty of Geosciences, Princetonlaan 4, 3584CD Utrecht, The Netherlands; n.krstekanic@uu.nl","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45134665","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 : 2021-01-15DOI: 10.31577/GEOLCARP.71.6.1
I. Petrik, M. Janák, T. Vaculovič, P. Konečný, Š. Méres
In view of a polyphase development of the northern Veporic pre-Alpine basement of the Western Carpathians it is important to determine the age of high pressure (HP) metamorphism known from eclogites occurring in this area. To do this, several monazite-bearing paragneisses were studied petrologically and monazite was dated by chemical (U–Th–Pb) method. Identified were remnants from high-pressure stage, i.e. phengite (Si apfu = 3.2–3.3), kyanite, rutile and Ca-rich garnet rims. Part of the present mineral assemblage may have been preserved from prograde stage (plagioclase) and part reflects re-equilibration during retrogression (biotite, major elements in garnet cores). However, Y and HREE in garnet cores were not homogenised and their profiles indicate origin during temperature rise. Peak metamorphic conditions (P = 21 kbar; T = 650 °C), and retrogression stage (P = 9 kbar; T = 520 °C) were calculated using Zr-in-rutile, and Y-in-garnet and monazite thermometry, phengite composition and pseudosection modelling. Monazite yielded dominant Early Carboniferous age (354 Ma) with subordinate amounts of Ordovician (485 Ma) and Cambrian (505 Ma) ones, and no Alpine record. The monazite position in garnet cores predating the growth of Ca rims suggest that the Carboniferous age of 354 Ma probably predates the peak conditions and refers to the prograde stage of the Variscan metamorphic evolution.
{"title":"Variscan high-pressure metamorphism of kyanite-bearing paragneisses hosting eclogites in the Veporic unit, Western Carpathians: Evidence from Th–U–Pb dating of monazite","authors":"I. Petrik, M. Janák, T. Vaculovič, P. Konečný, Š. Méres","doi":"10.31577/GEOLCARP.71.6.1","DOIUrl":"https://doi.org/10.31577/GEOLCARP.71.6.1","url":null,"abstract":"In view of a polyphase development of the northern Veporic pre-Alpine basement of the Western Carpathians it is important to determine the age of high pressure (HP) metamorphism known from eclogites occurring in this area. To do this, several monazite-bearing paragneisses were studied petrologically and monazite was dated by chemical (U–Th–Pb) method. Identified were remnants from high-pressure stage, i.e. phengite (Si apfu = 3.2–3.3), kyanite, rutile and Ca-rich garnet rims. Part of the present mineral assemblage may have been preserved from prograde stage (plagioclase) and part reflects re-equilibration during retrogression (biotite, major elements in garnet cores). However, Y and HREE in garnet cores were not homogenised and their profiles indicate origin during temperature rise. Peak metamorphic conditions (P = 21 kbar; T = 650 °C), and retrogression stage (P = 9 kbar; T = 520 °C) were calculated using Zr-in-rutile, and Y-in-garnet and monazite thermometry, phengite composition and pseudosection modelling. Monazite yielded dominant Early Carboniferous age (354 Ma) with subordinate amounts of Ordovician (485 Ma) and Cambrian (505 Ma) ones, and no Alpine record. The monazite position in garnet cores predating the growth of Ca rims suggest that the Carboniferous age of 354 Ma probably predates the peak conditions and refers to the prograde stage of the Variscan metamorphic evolution.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48447460","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 : 2021-01-01DOI: 10.31577/geolcarp.72.3.3
Serdar Akgündüz, H. Koral
The Thrace Basin consists of Paleogene–Neogene deposits that lie in the lowland south of the Strandja highlands in NW Turkey, where metagranitic and metasedimentary rocks occur. The Akalan Formation consisting of colluvial fan/debris flow deposits represents the base of the sequence in the northern Thrace basin where it is bounded by a right lateral strike-slip oblique fault called “The Western Strandja Fault Zone”. This formation exhibits a coarse-grained, angular and grain-supported character close to the fault zone which has releasing-bends. Fine-grained, rounded, and matrix-supported sediments occur away from the contact. During this study, the Akalan Formation is described for the first time as having larger benthic foraminifera (LBF) of Coskinolina sp of Ypresian–Lutetian, Nummulites obesus of early Lutetian, Dictyoconus egyptiensis of Lutetian, Orbitolites sp. of Ypresian–Bartonian, Miliola sp of early–middle Eocene, Idalina grelaudae of early Lutetian–Priabonian, Ammobaculites agglutinans, Amphimorphina crassa, Dentalina sp., Nodosaria sp., Operculina sp., Lenticulina sp., Quinqueloculina sp. and Amphistegina sp. of Eocene. This unit passes upward with a conformity into reefal limestones of the middle/late Eocene–early Oligocene Soğucak Formation. At times, the limestone overlies the conformity, there is an indication of a prograding sedimentary sequence. The new stratigraphic, paleontological, sedimentological and structural findings related to the NW Thrace Basin suggest a strong transtensional/extensional tectonic control for the initial Paleogene sedimentary deposition during the Ypresian–Lutetian period as shown by fossil content of the Akalan Formation. Right lateral-slip extensional tectonics appears to have had activity during the middle–late Eocene transgressive deposition of the Soğucak Formation when the basin became deepened and enlarged.
{"title":"Paleogene extension in the Northern Aegean: Colluvial/debris flow deposits of the Early-Middle Eocene in NW Thrace Basin, Turkey","authors":"Serdar Akgündüz, H. Koral","doi":"10.31577/geolcarp.72.3.3","DOIUrl":"https://doi.org/10.31577/geolcarp.72.3.3","url":null,"abstract":"The Thrace Basin consists of Paleogene–Neogene deposits that lie in the lowland south of the Strandja highlands in NW Turkey, where metagranitic and metasedimentary rocks occur. The Akalan Formation consisting of colluvial fan/debris flow deposits represents the base of the sequence in the northern Thrace basin where it is bounded by a right lateral strike-slip oblique fault called “The Western Strandja Fault Zone”. This formation exhibits a coarse-grained, angular and grain-supported character close to the fault zone which has releasing-bends. Fine-grained, rounded, and matrix-supported sediments occur away from the contact. During this study, the Akalan Formation is described for the first time as having larger benthic foraminifera (LBF) of Coskinolina sp of Ypresian–Lutetian, Nummulites obesus of early Lutetian, Dictyoconus egyptiensis of Lutetian, Orbitolites sp. of Ypresian–Bartonian, Miliola sp of early–middle Eocene, Idalina grelaudae of early Lutetian–Priabonian, Ammobaculites agglutinans, Amphimorphina crassa, Dentalina sp., Nodosaria sp., Operculina sp., Lenticulina sp., Quinqueloculina sp. and Amphistegina sp. of Eocene. This unit passes upward with a conformity into reefal limestones of the middle/late Eocene–early Oligocene Soğucak Formation. At times, the limestone overlies the conformity, there is an indication of a prograding sedimentary sequence. The new stratigraphic, paleontological, sedimentological and structural findings related to the NW Thrace Basin suggest a strong transtensional/extensional tectonic control for the initial Paleogene sedimentary deposition during the Ypresian–Lutetian period as shown by fossil content of the Akalan Formation. Right lateral-slip extensional tectonics appears to have had activity during the middle–late Eocene transgressive deposition of the Soğucak Formation when the basin became deepened and enlarged.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70013351","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 : 2021-01-01DOI: 10.31577/geolcarp.72.2.2
Milan Kohút, Alexander N. Larionov
Granitic rocks from the core mountains of the Tatric Superunit (Western Carpathians, Slovakia) were dated by means of the sensitive high-resolution ion microprobe (SHRIMP) zircon U–Th–Pb method. The dated granitic rocks yielded a broad interval of the Concordia ages from 365 ± 5 Ma to 332 ± 3 Ma and largely invalidated the former hypothesis of a duality/antagonism in emplacement ages of the Variscan Sand I-type granites (Mississippian vs. Pennsylvanian) in the Central Western Carpathians (CWC). Generally, the obtained magmatic ages cluster in two separate intervals reflecting different stages of orogeny. The older, Famennian–Tournaisian event (365–350 Ma) was related to subduction of the Rheic Ocean, whereas the younger, mostly Visean event (348–332 Ma) was associated with collisional melting. The Th/U ratios of analysed zircons are compatible mainly with their magmatic origin (Th/U > 0.2), while the lower ones (Th/U < 0.1) in some zircons can indicate competition for Th with monazite and allanite, commonly present in the analysed granitic rocks. The new dating confirmed common zircon inheritance in Western Carpathian granites with inherited zircon cores showing the Neo-Archean to Paleo-Proterozoic (2800–1690 Ma) and Ediacaran to Late Ordovician (623–448 Ma) ages. The lack of any significant differences in magmatic/emplacement ages and the common “dirty” or hybrid character of both Iand S-type granites in the CWC indicate that the melted, often mixed sources and/or subsequent modification by hybridization and assimilation processes were mostly responsible for their general “alphabetic” designation (I-/S-type).
{"title":"From subduction to collision: Genesis of the Variscan granitic rocks from the Tatric Superunit (Western Carpathians, Slovakia)","authors":"Milan Kohút, Alexander N. Larionov","doi":"10.31577/geolcarp.72.2.2","DOIUrl":"https://doi.org/10.31577/geolcarp.72.2.2","url":null,"abstract":"Granitic rocks from the core mountains of the Tatric Superunit (Western Carpathians, Slovakia) were dated by means of the sensitive high-resolution ion microprobe (SHRIMP) zircon U–Th–Pb method. The dated granitic rocks yielded a broad interval of the Concordia ages from 365 ± 5 Ma to 332 ± 3 Ma and largely invalidated the former hypothesis of a duality/antagonism in emplacement ages of the Variscan Sand I-type granites (Mississippian vs. Pennsylvanian) in the Central Western Carpathians (CWC). Generally, the obtained magmatic ages cluster in two separate intervals reflecting different stages of orogeny. The older, Famennian–Tournaisian event (365–350 Ma) was related to subduction of the Rheic Ocean, whereas the younger, mostly Visean event (348–332 Ma) was associated with collisional melting. The Th/U ratios of analysed zircons are compatible mainly with their magmatic origin (Th/U > 0.2), while the lower ones (Th/U < 0.1) in some zircons can indicate competition for Th with monazite and allanite, commonly present in the analysed granitic rocks. The new dating confirmed common zircon inheritance in Western Carpathian granites with inherited zircon cores showing the Neo-Archean to Paleo-Proterozoic (2800–1690 Ma) and Ediacaran to Late Ordovician (623–448 Ma) ages. The lack of any significant differences in magmatic/emplacement ages and the common “dirty” or hybrid character of both Iand S-type granites in the CWC indicate that the melted, often mixed sources and/or subsequent modification by hybridization and assimilation processes were mostly responsible for their general “alphabetic” designation (I-/S-type).","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70013204","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 : 2021-01-01DOI: 10.31577/geolcarp.72.2.3
O. Němec, A. Vozárová, Katarína Šarinová, R. Anczkiewicz
The paper presents whole rock chemical composition and Sr–Nd isotope data from selected metabasic rocks from the Mississippian and Pennsylvanian sequences of the Northern Gemeric Unit. The analysed metabasic rocks belong to the subalkaline magmatic series with Nb/Y ratios ranging from 0.03 to 0.21. They fit into the low-Ti tholeiitic series, characterized by TiO2 contents of less than 2.5 wt. % and Ti/Y ratios below 500. Petrological and chemical signatures show the separation of the Group I (Pennsylvanian) from the Group II (Mississippian) metabasalts, which is supported by biostratigraphical data of the surrounding metasediments. The Group I metabasalts display higher contents of Zr, Th, Rb and U, Pb, Zn, Ni compared to the metabasalts of Group II and conversely lower contents of Nb, Ta and V. The chondrite normalized rare earth elements curves show a uniform pattern, with rare earth element enrichment and no or weak positive or negative Eu anomalies (0.88–1.23 vs. 0.89–1.17). The (Tb/Yb)N ratios from 1.36–1.62 in the Group I or 0.92–1.55 in Group II are symptomatic of spinel-bearing peridotite mantle source. Based on trace and rare earth element distribution patterns, the Group I metabasites correspond to the N-MORB/E-MORB field and the Group II metabasites shift significantly towards the BABB and CAB fields. The Sr/Nd isotope systematics confirmed depleted mantle isotopic signatures, with minor influences from crustal sources and affected by fluid-related subduction metasomatism. All the studied samples have positive εNd(0) ranging from 7.92 to 8.68 for Group I and from 4.59 to 10.52 for Group II metabasalts. The Sr/Sr(0) values vary between 0.7053–0.7081 and between 0.7052–0.7076, respectively, and 0.7109 for basaltic andesite.
{"title":"Carboniferous mafic metavolcanic rocks in the Northern Gemeric Unit: Petrogenesis, geochemistry, isotope composition and tectonic implication","authors":"O. Němec, A. Vozárová, Katarína Šarinová, R. Anczkiewicz","doi":"10.31577/geolcarp.72.2.3","DOIUrl":"https://doi.org/10.31577/geolcarp.72.2.3","url":null,"abstract":"The paper presents whole rock chemical composition and Sr–Nd isotope data from selected metabasic rocks from the Mississippian and Pennsylvanian sequences of the Northern Gemeric Unit. The analysed metabasic rocks belong to the subalkaline magmatic series with Nb/Y ratios ranging from 0.03 to 0.21. They fit into the low-Ti tholeiitic series, characterized by TiO2 contents of less than 2.5 wt. % and Ti/Y ratios below 500. Petrological and chemical signatures show the separation of the Group I (Pennsylvanian) from the Group II (Mississippian) metabasalts, which is supported by biostratigraphical data of the surrounding metasediments. The Group I metabasalts display higher contents of Zr, Th, Rb and U, Pb, Zn, Ni compared to the metabasalts of Group II and conversely lower contents of Nb, Ta and V. The chondrite normalized rare earth elements curves show a uniform pattern, with rare earth element enrichment and no or weak positive or negative Eu anomalies (0.88–1.23 vs. 0.89–1.17). The (Tb/Yb)N ratios from 1.36–1.62 in the Group I or 0.92–1.55 in Group II are symptomatic of spinel-bearing peridotite mantle source. Based on trace and rare earth element distribution patterns, the Group I metabasites correspond to the N-MORB/E-MORB field and the Group II metabasites shift significantly towards the BABB and CAB fields. The Sr/Nd isotope systematics confirmed depleted mantle isotopic signatures, with minor influences from crustal sources and affected by fluid-related subduction metasomatism. All the studied samples have positive εNd(0) ranging from 7.92 to 8.68 for Group I and from 4.59 to 10.52 for Group II metabasalts. The Sr/Sr(0) values vary between 0.7053–0.7081 and between 0.7052–0.7076, respectively, and 0.7109 for basaltic andesite.","PeriodicalId":12545,"journal":{"name":"Geologica Carpathica","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70012826","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：