M. Lindner, W. Dörr, C. Hauzenberger, Daniel Reither, F. Finger
Abstract For a long time, the 1.38 Ga old Dobra Gneiss (Type A) from the Lower Austrian Drosendorf Unit (Moldanubian Zone, Bohemian Massif) was considered the oldest rock of Austria. We now have dated zircons from a local mafic inlayer in the Dobra Gneiss Type A, termed Hauergraben Gneiss. This small-scale amphibole-bearing orthogneiss has a magmatic formation age of 1.40 Ga, and is, thus, to the present state of knowledge, the oldest rock of Austria. Based on geochemical investigations, the protolith of the Hauergraben Gneiss was a quartz-monzonite. It probably originated in a volcanic arc setting like the Dobra Gneiss, but shows distinctively higher transitional metal contents (especially Cr and Co), higher Ba and Sr, and higher light rare earth element contents, which hint at a lithospheric mantle input. This 1.40 Ga old mafic arc material was then incorporated into the 1.38 Ga old intrusive protolith of the Dobra Gneiss, probably in the form of enclaves. Considering the model that the Drosendorf Unit was part of Amazonia until the late Neoproterozoic, we propose that both, Dobra Gneiss Type A and Hauergraben Gneiss, originated at the western margin of the Columbia super-continent, where several long-lived Mesoproterozoic volcanic arcs existed and accreted over time. During the Variscan orogeny, the Hauergraben Gneiss experienced peak metamorphic temperatures of ~620 °C at pressures of ~6 kbar, as can be deduced from amphibole thermobarometry. This is in line with published peak-PT estimates from other parts of the Drosendorf Unit. Formation of secondary low-Al magnesiohornblende at the expense of the earlier edenitic/pargasitic peak amphibole indicates a subsequent retrograde overprint.
{"title":"In search of the oldest rock of Austria: The Hauergraben Gneiss, a 1.40 Ga old mafic quartz-monzonitic inlayer in the Dobra Gneiss (Drosendorf Unit, Bohemian Massif) as a new candidate","authors":"M. Lindner, W. Dörr, C. Hauzenberger, Daniel Reither, F. Finger","doi":"10.17738/ajes.2021.0002","DOIUrl":"https://doi.org/10.17738/ajes.2021.0002","url":null,"abstract":"Abstract For a long time, the 1.38 Ga old Dobra Gneiss (Type A) from the Lower Austrian Drosendorf Unit (Moldanubian Zone, Bohemian Massif) was considered the oldest rock of Austria. We now have dated zircons from a local mafic inlayer in the Dobra Gneiss Type A, termed Hauergraben Gneiss. This small-scale amphibole-bearing orthogneiss has a magmatic formation age of 1.40 Ga, and is, thus, to the present state of knowledge, the oldest rock of Austria. Based on geochemical investigations, the protolith of the Hauergraben Gneiss was a quartz-monzonite. It probably originated in a volcanic arc setting like the Dobra Gneiss, but shows distinctively higher transitional metal contents (especially Cr and Co), higher Ba and Sr, and higher light rare earth element contents, which hint at a lithospheric mantle input. This 1.40 Ga old mafic arc material was then incorporated into the 1.38 Ga old intrusive protolith of the Dobra Gneiss, probably in the form of enclaves. Considering the model that the Drosendorf Unit was part of Amazonia until the late Neoproterozoic, we propose that both, Dobra Gneiss Type A and Hauergraben Gneiss, originated at the western margin of the Columbia super-continent, where several long-lived Mesoproterozoic volcanic arcs existed and accreted over time. During the Variscan orogeny, the Hauergraben Gneiss experienced peak metamorphic temperatures of ~620 °C at pressures of ~6 kbar, as can be deduced from amphibole thermobarometry. This is in line with published peak-PT estimates from other parts of the Drosendorf Unit. Formation of secondary low-Al magnesiohornblende at the expense of the earlier edenitic/pargasitic peak amphibole indicates a subsequent retrograde overprint.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46643192","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}
Abstract Deep-neritic sediments of the Eferding Formation (Egerian, Upper Oligocene) of Upper Austria from the Kamig kaolinite quarry revealed minute teeth of the putatively planktivorous shark genus Nanocetorhinus. This is the oldest unambiguous record of this rarely documented genus, which was known so far only from Miocene deposits of Europe, North America and Japan. Based on previous studies, which showed a positive correlation between sediments of nutrient rich waters and plankton blooms with a majority of ichthyoliths of Keasius and Nanocetorhinus, we argue for a filter-feeding and migratory lifestyle of the latter. Thus, it is supposed that Nanocetorhinus migrated seasonally for foraging, in a similar way to the extant basking shark Cetorhinus maximus. This mode of life and the wide paleogeographic distribution of the open marine genus Nanocetorhinus requires a deep and fully marine connection between the Paratethys and the Proto-Mediterranean Sea during late Oligocene times, which might have been established via the Slovenian Corridor.
{"title":"A new species of the enigmatic shark genus Nanocetorhinus (Chondrichthyes) from the Oligocene of Austria with palaeoceanographic implications","authors":"I. Feichtinger, J. Pollerspöck, M. Harzhauser","doi":"10.17738/ajes.2020.0014","DOIUrl":"https://doi.org/10.17738/ajes.2020.0014","url":null,"abstract":"Abstract Deep-neritic sediments of the Eferding Formation (Egerian, Upper Oligocene) of Upper Austria from the Kamig kaolinite quarry revealed minute teeth of the putatively planktivorous shark genus Nanocetorhinus. This is the oldest unambiguous record of this rarely documented genus, which was known so far only from Miocene deposits of Europe, North America and Japan. Based on previous studies, which showed a positive correlation between sediments of nutrient rich waters and plankton blooms with a majority of ichthyoliths of Keasius and Nanocetorhinus, we argue for a filter-feeding and migratory lifestyle of the latter. Thus, it is supposed that Nanocetorhinus migrated seasonally for foraging, in a similar way to the extant basking shark Cetorhinus maximus. This mode of life and the wide paleogeographic distribution of the open marine genus Nanocetorhinus requires a deep and fully marine connection between the Paratethys and the Proto-Mediterranean Sea during late Oligocene times, which might have been established via the Slovenian Corridor.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49523390","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}
Gerit E. U. Griesmeier, C. Iglseder, R. Schuster, K. Petrakakis
Abstract This work describes the Freyenstein Fault System, which extends over 45 km in the southeastern part of the Bohemian Massif (Lower Austria). It represents a ductile shear zone overprinted by a brittle fault located at the eastern edge of the South Bohemian Batholith towards the Moldanubian nappes. It affects Weinsberg- and a more “fine-grained” granite, interlayered aplitic granite and pegmatite dikes as well as paragneiss of the Ostrong Nappe System. The ductile shear zone is represented by approximately 500 m thick greenschist-facies mylonite dipping about 60° to the southeast. Shear-sense criteria like clast geometries, SCC`-type shear band fabrics as well as abundant microstructures show top to the south/ southsouthwest normal shearing with a dextral strike-slip component. Mineral assemblages in mylonitized granitoid consist of pre- to syntectonic muscovite- and biotite-porphyroclasts as well as dynamically recrystallized potassium feldspar, plagioclase and quartz. Dynamic recrystallization of potassium feldspar and the stability of biotite indicate upper green-schist-facies metamorphic conditions during the early phase of deformation. Fluid infiltration at lower greenschist-facies conditions led to local sericitization of feldspar and synmylonitic chloritisation of biotite during a later stage of ductile deformation. Finally, a brittle overprint by a north-south trending, subvertical, sinistral strike-slip fault that shows a normal component is observed. Ductile normal shearing along the Freyenstein Shear Zone is interpreted to have occurred between 320 Ma and c. 300 Ma. This time interval is indicated by literature data on the emplacement of the hostrock and cooling below c. 300°C inferred from two Rb-Sr biotite ages measured on undeformed granites close to the shear zone yielding 309.6 ± 3 Ma and 290.9 ± 2.9 Ma, respectively. Brittle sinistral strike-slip faulting at less than 300°C presumably took place not earlier than 300 Ma. Early ductile shearing along the Freyenstein Fault System may be genetically, but not kinematically linked to the Strudengau Shear Zone, as both acted in an extensional regime during late Variscan orogenic collapse. A relation to other major northeast-southwest trending faults of this part of the Bohemian Massif (e.g. the Vitis-Pribyslav Fault System) is indicated for the phase of brittle sinistral movement.
{"title":"Polyphase deformation along the South Bohemian Batholith-Moldanubian nappes boundary – The Freyenstein Fault System (Bohemian Massif/Austria)","authors":"Gerit E. U. Griesmeier, C. Iglseder, R. Schuster, K. Petrakakis","doi":"10.17738/ajes.2020.0009","DOIUrl":"https://doi.org/10.17738/ajes.2020.0009","url":null,"abstract":"Abstract This work describes the Freyenstein Fault System, which extends over 45 km in the southeastern part of the Bohemian Massif (Lower Austria). It represents a ductile shear zone overprinted by a brittle fault located at the eastern edge of the South Bohemian Batholith towards the Moldanubian nappes. It affects Weinsberg- and a more “fine-grained” granite, interlayered aplitic granite and pegmatite dikes as well as paragneiss of the Ostrong Nappe System. The ductile shear zone is represented by approximately 500 m thick greenschist-facies mylonite dipping about 60° to the southeast. Shear-sense criteria like clast geometries, SCC`-type shear band fabrics as well as abundant microstructures show top to the south/ southsouthwest normal shearing with a dextral strike-slip component. Mineral assemblages in mylonitized granitoid consist of pre- to syntectonic muscovite- and biotite-porphyroclasts as well as dynamically recrystallized potassium feldspar, plagioclase and quartz. Dynamic recrystallization of potassium feldspar and the stability of biotite indicate upper green-schist-facies metamorphic conditions during the early phase of deformation. Fluid infiltration at lower greenschist-facies conditions led to local sericitization of feldspar and synmylonitic chloritisation of biotite during a later stage of ductile deformation. Finally, a brittle overprint by a north-south trending, subvertical, sinistral strike-slip fault that shows a normal component is observed. Ductile normal shearing along the Freyenstein Shear Zone is interpreted to have occurred between 320 Ma and c. 300 Ma. This time interval is indicated by literature data on the emplacement of the hostrock and cooling below c. 300°C inferred from two Rb-Sr biotite ages measured on undeformed granites close to the shear zone yielding 309.6 ± 3 Ma and 290.9 ± 2.9 Ma, respectively. Brittle sinistral strike-slip faulting at less than 300°C presumably took place not earlier than 300 Ma. Early ductile shearing along the Freyenstein Fault System may be genetically, but not kinematically linked to the Strudengau Shear Zone, as both acted in an extensional regime during late Variscan orogenic collapse. A relation to other major northeast-southwest trending faults of this part of the Bohemian Massif (e.g. the Vitis-Pribyslav Fault System) is indicated for the phase of brittle sinistral movement.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41793190","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}
Abstract The Kellerjoch forms a small isolated massif at the northernmost rim of the central Eastern Alps of Tyrol and shows a number of geomorphological features of glacial and periglacial origin. Mapping yields evidence of two local glaciations postdating the Last Glacial Maximum. Using a simple glaciological approach the palaeoglaciers related to these events were reconstructed. The older glaciation yields an equilibrium line altitude (ELA) ranging from 1660 m for the maximum extent to 1800 m a.s.l. for the innermost moraine. For the younger glaciation, ELAs were reconstructed at 1905 m and 1980 m (depending on the reconstruction) for the Kellerjoch palaeoglacier 2, as well as 1870 m and 2060 m a.s.l. for the Proxen palaeoglacier and the Gart palaeoglacier, respectively. A comparison with published data from the Eastern Alps shows that the older glaciation in the Kellerjoch region likely corresponds to the Gschnitz stadial. Low basal shear stresses of the glacier tongues point towards a cold and dry climate, similar to the reconstruction for the Gschnitz type locality at Trins. The younger glaciation cannot unambiguously be assigned to a specific Late Glacial ice advance, but a Younger Dryas age is a distinct possibility.
摘要Kellerjoch在蒂罗尔阿尔卑斯山脉中东部的最北端形成了一个孤立的小山丘，并显示出许多冰川和冰缘地貌特征。地图绘制提供了两次局部冰川作用的证据，这两次冰川作用的年代是上一次冰川盛期之后。使用简单的冰川学方法重建了与这些事件有关的古冰川。较老的冰川作用产生了平衡线海拔（ELA），最大范围为1660米，最内侧冰碛的海拔为1800米。对于较年轻的冰川作用，Kellerjoch古冰川2在1905 m和1980 m（取决于重建情况）重建了ELA，Proxen古冰川和Gart古冰川分别在1870 m和2060 m a.s.l.重建。与东阿尔卑斯山公布的数据进行比较表明，Kellerjoch地区较古老的冰川作用可能与Gschnitz体育场相对应。冰川舌的低基底剪切应力指向寒冷干燥的气候，类似于Trins Gschnitz型地区的重建。较年轻的冰川作用不能明确地归属于特定的晚冰川作用，但较年轻的Dryas年龄是一种明显的可能性。
{"title":"Late Glacial ice advance in the Kellerjoch region near Schwaz (Tyrol, Eastern Alps)","authors":"Philipp Gschwentner, H. Kerschner, C. Spötl","doi":"10.17738/ajes.2020.0013","DOIUrl":"https://doi.org/10.17738/ajes.2020.0013","url":null,"abstract":"Abstract The Kellerjoch forms a small isolated massif at the northernmost rim of the central Eastern Alps of Tyrol and shows a number of geomorphological features of glacial and periglacial origin. Mapping yields evidence of two local glaciations postdating the Last Glacial Maximum. Using a simple glaciological approach the palaeoglaciers related to these events were reconstructed. The older glaciation yields an equilibrium line altitude (ELA) ranging from 1660 m for the maximum extent to 1800 m a.s.l. for the innermost moraine. For the younger glaciation, ELAs were reconstructed at 1905 m and 1980 m (depending on the reconstruction) for the Kellerjoch palaeoglacier 2, as well as 1870 m and 2060 m a.s.l. for the Proxen palaeoglacier and the Gart palaeoglacier, respectively. A comparison with published data from the Eastern Alps shows that the older glaciation in the Kellerjoch region likely corresponds to the Gschnitz stadial. Low basal shear stresses of the glacier tongues point towards a cold and dry climate, similar to the reconstruction for the Gschnitz type locality at Trins. The younger glaciation cannot unambiguously be assigned to a specific Late Glacial ice advance, but a Younger Dryas age is a distinct possibility.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43945766","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}
Abstract Historical fossil assemblages from the Lower Jurassic to Lower Cretaceous of the Sankt Veit Klippen Unit (SVK) on the western outskirts of Vienna were re-evaluated. Collections of the material from the St. Veit Klippen Unit comprise 3497 specimens. An appropriate nomenclature was used, and the taxonomy was partly revised. Historical collections from Franz Toula (1845–1920) and Friedrich Trauth (1883–1967) were investigated in the collections of the Natural History Museum Vienna, the Geological Survey Vienna, the Department of Geology and the Department of Palaeontology (both University Vienna). Additional collections were studied in the district museums Hietzing (13th district Vienna) and Liesing (23rd district Vienna), in the district municipal office of Hietzing and in the Wienerwald Museum (Eichgraben, Lower Austria). The study area is situated in the easternmost part of the St. Veit Klippen Unit in the Wienerwald (Vienna Woods), part of the 13th Viennese district Hietzing. New data allowed a revision of the biostratigraphy of several lithological units of the SVK. Two main fossil complexes could be distinguished: 1) the Hohenauer Wiese assemblage from the wildlife park Lainz (= “Lainzer Tiergarten”) and 2) the Glasauer quarry assemblage from St. Veit.
{"title":"The St. Veit Klippen Unit in Vienna (Austria) – Jurassic to Cretaceous biostratigraphy and facies based on historical fossil collections","authors":"A. Lukeneder, P. Lukeneder, M. Harzhauser","doi":"10.17738/ajes.2020.0016","DOIUrl":"https://doi.org/10.17738/ajes.2020.0016","url":null,"abstract":"Abstract Historical fossil assemblages from the Lower Jurassic to Lower Cretaceous of the Sankt Veit Klippen Unit (SVK) on the western outskirts of Vienna were re-evaluated. Collections of the material from the St. Veit Klippen Unit comprise 3497 specimens. An appropriate nomenclature was used, and the taxonomy was partly revised. Historical collections from Franz Toula (1845–1920) and Friedrich Trauth (1883–1967) were investigated in the collections of the Natural History Museum Vienna, the Geological Survey Vienna, the Department of Geology and the Department of Palaeontology (both University Vienna). Additional collections were studied in the district museums Hietzing (13th district Vienna) and Liesing (23rd district Vienna), in the district municipal office of Hietzing and in the Wienerwald Museum (Eichgraben, Lower Austria). The study area is situated in the easternmost part of the St. Veit Klippen Unit in the Wienerwald (Vienna Woods), part of the 13th Viennese district Hietzing. New data allowed a revision of the biostratigraphy of several lithological units of the SVK. Two main fossil complexes could be distinguished: 1) the Hohenauer Wiese assemblage from the wildlife park Lainz (= “Lainzer Tiergarten”) and 2) the Glasauer quarry assemblage from St. Veit.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47027999","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}
Abstract In the course of foundation works in the Dürnstein Castle cervical and front leg bones of a large Bison priscus bull were discovered in fluvial sediments. The small city of Dürnstein with its medieval centre is part of the UNESCO Wachau Cultural Landscape and is built mainly on Palaeozoic basement rocks. The find location is completely overbuilt, but remnants of fluvial sediments on the bones together with the altitude of the site approximately 17 m above the Danube point to a Middle Pleistocene fluvial aggradation level not younger than ca. 240,000 years, and the maximum age is 400,000 years. The fossil bearing location is interpreted as a small sandy bay of the Pleistocene Danube, protected from later degradation and erosion. Morphometric comparisons and taphonomic analyses of the bones allow the reconstruction of a scenario in which the bison probably had drowned in a flood and its carcass was buried quickly before destruction by scavengers or erosion. The study includes a comparison with bison specimens of an unpublished small megafaunal assemblage from adjacent Krems-Kreuzbergstraße. Processing marks on parts of these bones point to an anthropogenic Middle Palaeolithic influence and translocation. In addition, a tentative chronological sketch of the regional Bison species succession (B. menneri, B. schoetensacki, B. priscus) from the Early to the Late Pleistocene is presented.
{"title":"A Middle Pleistocene steppe bison find within the Dürnstein Castle (Wachau, Lower Austria)","authors":"F. Fladerer, Reinhard Roetzel, K. Veitschegger","doi":"10.17738/ajes.2020.0015","DOIUrl":"https://doi.org/10.17738/ajes.2020.0015","url":null,"abstract":"Abstract In the course of foundation works in the Dürnstein Castle cervical and front leg bones of a large Bison priscus bull were discovered in fluvial sediments. The small city of Dürnstein with its medieval centre is part of the UNESCO Wachau Cultural Landscape and is built mainly on Palaeozoic basement rocks. The find location is completely overbuilt, but remnants of fluvial sediments on the bones together with the altitude of the site approximately 17 m above the Danube point to a Middle Pleistocene fluvial aggradation level not younger than ca. 240,000 years, and the maximum age is 400,000 years. The fossil bearing location is interpreted as a small sandy bay of the Pleistocene Danube, protected from later degradation and erosion. Morphometric comparisons and taphonomic analyses of the bones allow the reconstruction of a scenario in which the bison probably had drowned in a flood and its carcass was buried quickly before destruction by scavengers or erosion. The study includes a comparison with bison specimens of an unpublished small megafaunal assemblage from adjacent Krems-Kreuzbergstraße. Processing marks on parts of these bones point to an anthropogenic Middle Palaeolithic influence and translocation. In addition, a tentative chronological sketch of the regional Bison species succession (B. menneri, B. schoetensacki, B. priscus) from the Early to the Late Pleistocene is presented.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42011571","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}
Abstract Carnian metapelites from the southeastern segment of the Mürzalpen Nappe (Northern Calcareous Alps, Eastern Alps) were heated to 280-310 °C, estimated by Raman spectroscopy of carbonaceous material (RSCM). This temperature range is correlated to a Color Alteration Index of 5.0-6.5, determined on conodonts from adjacent Anisian to Norian carbonates. Average RSCM temperatures estimated on the conodonts are biased towards higher temperatures. The spectral characteristics of the conodont apatite suggest a composition altered during progressive recrystallization, influencing the band parameters of the included carbonaceous matter. Consequently, accurate conodont RSCM thermometry needs an assessment of apatite alteration.
{"title":"Conodont thermometry by Raman spectroscopy on carbonaceous material: a case study from the Northern Calcareous Alps (Mürzalpen Nappe, Eastern Alps)","authors":"G. Rantitsch, Gerhard Bryda, H. Gawlick","doi":"10.17738/ajes.2020.0012","DOIUrl":"https://doi.org/10.17738/ajes.2020.0012","url":null,"abstract":"Abstract Carnian metapelites from the southeastern segment of the Mürzalpen Nappe (Northern Calcareous Alps, Eastern Alps) were heated to 280-310 °C, estimated by Raman spectroscopy of carbonaceous material (RSCM). This temperature range is correlated to a Color Alteration Index of 5.0-6.5, determined on conodonts from adjacent Anisian to Norian carbonates. Average RSCM temperatures estimated on the conodonts are biased towards higher temperatures. The spectral characteristics of the conodont apatite suggest a composition altered during progressive recrystallization, influencing the band parameters of the included carbonaceous matter. Consequently, accurate conodont RSCM thermometry needs an assessment of apatite alteration.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48488944","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}
M. Harzhauser, M. Kranner, O. Mandic, P. Strauss, W. Siedl, W. Piller
Abstract For the first time, a concise lithostratigraphic scheme for the lower and middle Miocene (Ottnangian – Badenian) of the northern and central Vienna Basin is proposed, which is based on the integration of core-material, well-log data and seismic information from OMV. For all formations and members type sections are proposed, geographic distribution and thickness are provided, typical depositional environments and fossils are described and age constraints are discussed. This time frame allows for a more reliable calculation of sedimentation rates. This in turn might be important for the reconstruction of the tectonic history of the Vienna Basin as we do not see fundamental differences between the piggy-back stage and the subsequent pull-apart regime. Following lithostratigraphic units are formalized herein and/or are newly introduced: Bockfließ Formation (Ottnangian), Aderklaa Formation, Gänserndorf Member and Schönkirchen Member (Karpatian), Baden Group, Rothneusiedl Formation and Mannsdorf Formation (lower Badenian), Auersthal Formation, Matzen Formation, Baden Formation, Leitha Formation (middle Badenian) and Rabensburg Formation (upper Badenian).
{"title":"Miocene lithostratigraphy of the northern and central Vienna Basin (Austria)","authors":"M. Harzhauser, M. Kranner, O. Mandic, P. Strauss, W. Siedl, W. Piller","doi":"10.17738/ajes.2020.0011","DOIUrl":"https://doi.org/10.17738/ajes.2020.0011","url":null,"abstract":"Abstract For the first time, a concise lithostratigraphic scheme for the lower and middle Miocene (Ottnangian – Badenian) of the northern and central Vienna Basin is proposed, which is based on the integration of core-material, well-log data and seismic information from OMV. For all formations and members type sections are proposed, geographic distribution and thickness are provided, typical depositional environments and fossils are described and age constraints are discussed. This time frame allows for a more reliable calculation of sedimentation rates. This in turn might be important for the reconstruction of the tectonic history of the Vienna Basin as we do not see fundamental differences between the piggy-back stage and the subsequent pull-apart regime. Following lithostratigraphic units are formalized herein and/or are newly introduced: Bockfließ Formation (Ottnangian), Aderklaa Formation, Gänserndorf Member and Schönkirchen Member (Karpatian), Baden Group, Rothneusiedl Formation and Mannsdorf Formation (lower Badenian), Auersthal Formation, Matzen Formation, Baden Formation, Leitha Formation (middle Badenian) and Rabensburg Formation (upper Badenian).","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49344047","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}
Abstract Foraminiferal assemblages from Upper Jurassic Klentnice beds in Lower Austria are described and analysed. The early late Tithonian assemblages comprise 75 foraminiferal taxa and simple diversities reach up to 31 taxa per sample, pointing to comparatively high diversity in general. The assemblages are dominated by lenticulinid forms (Genera Astacolus, Lenticulina, Saracenaria, Vaginulinopsis). Trocholina is the most common genus and present in all samples. Other frequent genera are Marssonella and Neobulimina. Co-occurrence of epifaunal (grazing) herbivores and epi- to deep infaunal active deposit feeders points to mixed assemblages from different sources and supports the concept of turbiditic systems as prevailing sedimentary regimes in the basinal setting.
{"title":"Late Jurassic foraminifera from the southern Waschberg-Ždánice Unit (Klentnice beds, Lower Austria)","authors":"H. Gebhardt","doi":"10.17738/ajes.2020.0010","DOIUrl":"https://doi.org/10.17738/ajes.2020.0010","url":null,"abstract":"Abstract Foraminiferal assemblages from Upper Jurassic Klentnice beds in Lower Austria are described and analysed. The early late Tithonian assemblages comprise 75 foraminiferal taxa and simple diversities reach up to 31 taxa per sample, pointing to comparatively high diversity in general. The assemblages are dominated by lenticulinid forms (Genera Astacolus, Lenticulina, Saracenaria, Vaginulinopsis). Trocholina is the most common genus and present in all samples. Other frequent genera are Marssonella and Neobulimina. Co-occurrence of epifaunal (grazing) herbivores and epi- to deep infaunal active deposit feeders points to mixed assemblages from different sources and supports the concept of turbiditic systems as prevailing sedimentary regimes in the basinal setting.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45349774","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}
Abstract Aftershock identification plays an important role in the assessment and characterization of large earthquakes. Especially, the length of the aftershock sequence is an important aspect of declustering earthquake catalogues and therefore impacts the frequency of earthquakes in a certain region, which is important for future seismic hazard assessment. However, in intraplate regions with low deformation rates and low to moderate seismicity, it is still questionable if aftershocks after a major event may continue for much longer time. In this study, we use one of the earliest instrumentally recorded earthquakes, the 1906 Dobrá Voda earthquake (Ms/Imax=5.7/VIII-IX), to compare different approaches of aftershock determination and their suitability for understanding the recorded earthquake sequence. The Dobrá Voda segment of the Vienna Basin Transfer Fault System is one of the seismically most active zones in Slovakia with the 1906 earthquake as the strongest recorded earthquake. We first assess the epicentral intensity of the earthquake according to the Environmental Intensity Scale (ESI2007) using contemporary descriptions of earthquake effects. This additional information leads to constrain the maximal intensity to IESI2007=IX. This result agrees well with first the assessment of Imax in 1907 and indicates the reliability of this intensity data. In the second step, earthquake data are plotted for two spatial windows extending 13 km and 26 km from the epicenter of the mainshock, respectively. Despite uncertainties regarding the completeness of data due to war times and lack of nearby seismic stations, the overall temporal evolution of seismicity can apparently not be described as an Omori-type aftershock sequence following the event in 1906. Instead, earthquake occurrence within 13 km of the mainshock shows elevated earthquake activity right after the 1906 event that only decays to a lower level of activity within decades after the mainshock. The decline of seismicity therefore occurs over time scales which are much longer than those predicted by the Omori relation. We conclude that today’s seismic activity may still be affected by the 1906 earthquake.
{"title":"The 1906 Dobrá Voda Earthquake (M=5.7) at the Vienna Basin Transfer Fault: evaluation of the ESI2007 intensity and analysis of the aftershock sequence","authors":"Asma Nasir, E. Hintersberger, K. Decker","doi":"10.17738/ajes.2020.0003","DOIUrl":"https://doi.org/10.17738/ajes.2020.0003","url":null,"abstract":"Abstract Aftershock identification plays an important role in the assessment and characterization of large earthquakes. Especially, the length of the aftershock sequence is an important aspect of declustering earthquake catalogues and therefore impacts the frequency of earthquakes in a certain region, which is important for future seismic hazard assessment. However, in intraplate regions with low deformation rates and low to moderate seismicity, it is still questionable if aftershocks after a major event may continue for much longer time. In this study, we use one of the earliest instrumentally recorded earthquakes, the 1906 Dobrá Voda earthquake (Ms/Imax=5.7/VIII-IX), to compare different approaches of aftershock determination and their suitability for understanding the recorded earthquake sequence. The Dobrá Voda segment of the Vienna Basin Transfer Fault System is one of the seismically most active zones in Slovakia with the 1906 earthquake as the strongest recorded earthquake. We first assess the epicentral intensity of the earthquake according to the Environmental Intensity Scale (ESI2007) using contemporary descriptions of earthquake effects. This additional information leads to constrain the maximal intensity to IESI2007=IX. This result agrees well with first the assessment of Imax in 1907 and indicates the reliability of this intensity data. In the second step, earthquake data are plotted for two spatial windows extending 13 km and 26 km from the epicenter of the mainshock, respectively. Despite uncertainties regarding the completeness of data due to war times and lack of nearby seismic stations, the overall temporal evolution of seismicity can apparently not be described as an Omori-type aftershock sequence following the event in 1906. Instead, earthquake occurrence within 13 km of the mainshock shows elevated earthquake activity right after the 1906 event that only decays to a lower level of activity within decades after the mainshock. The decline of seismicity therefore occurs over time scales which are much longer than those predicted by the Omori relation. We conclude that today’s seismic activity may still be affected by the 1906 earthquake.","PeriodicalId":49319,"journal":{"name":"Austrian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42902287","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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