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Aleksandra Vierek - One of the best experts on this subject based on the ideXlab platform.
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The palaeogeographical background of Late Devonian storm events in the western part of the Holy Cross Mountains (Poland)
Geologos, 2013Co-Authors: Aleksandra VierekAbstract:Abstract Late Devonian coarse-grained carbonate deposits in the Holy Cross Mountains were studied for possible storm depositional systems and catastrophic tsunami events, as it must be assumed that the investigated area was strongly affected by tropical hurricanes generated in the open ocean North of Gondwana. This assumption appears consistent with diagnostic features of carbonate Tempestites at several places in the Holy Cross Mountains. Sedimentary structures and textures that indicate so are, among other evidence, erosional bases with sole marks, graded units, intra- and bioclasts, different laminations and burrowing at the tops of Tempestite layers. It has been suggested before that a tsunami occurred during the Late Devonian, but the Laurussian shelf had an extensional regime at the time, which excludes intensive seismic activity. The shelf environment also excluded the generation of tsunami waves because the depth was too shallow. Additionally, the Holy Cross Mountains region was surrounded in the Devonian by shallow-marine and stable elevated areas: the Nida Platform, the Opatkowice Platform and the Cracow Platform to the South, and the elevated Lublin-Lviv area to the NE. Thus, tsunami energy should have been absorbed by these regions if tsunamites would have occurred.
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Depositional versus ecological control on the conodont distribution in the Lower Frasnian fore-reef facies, Holy Cross Mountains, Poland
Palaeogeography Palaeoclimatology Palaeoecology, 2011Co-Authors: Aleksandra Vierek, Grzegorz RackiAbstract:Abstract Lithofacies and conodont biofacies of reef-slope deposits of the Wietrznia Beds (Lower Frasnian Palmatolepis transitans Zone) were studied in three measured sections at the Wietrznia quarry (Holy Cross Mts. Poland). The diverse reef-derived grained deposits interrupted the background sedimentation that included lime mudstones, deposited largely at 50 to 90 m depths in oxygen-depleted middle slope to toe of slope settings. The mainly storm-controlled proximal gradient is laterally marked by gradual changes from coarse-grained Tempestites, represented by flat-pebble conglomerate fabric, to diluted muddy Tempestites. The mostly sparse polygnathid and mesotaxid–polygnathid biofacies characterize the hemipelagic facies, whilst polygnathid–ancyrodellid biofacies dominates in the event layers. Three-step taphofacies scheme is proposed, distinguishing settled (parautochthonous), residual (winnowed) and displaced (settled from waning currents and/or transported in sediment-gravity flows) conodont element accumulations. The primary ecological signals are still partly preserved in most of the Tempestite-derived assemblages, indicating scarcity of truly residual, lag-like taphofacies. The hydraulic sorting was most effective in the middle-slope setting affected by unidirectional and/or oscillatory flows. Syndepositional mixing was strengthened upslope by an importation of off-reef mesotaxid faunas due to storm surge onto the reef. This reworking pattern as a key factor in biofacies interpretation may be applicable only on a local scale. However, similarly biased conodont signature is probably common in other hurricane-affected carbonate complexes, even if without a disrupting impact on major biofacies belts.
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Transitional reef-to-basin facies of Lower Frasnian limestones determined by microfacies analysis (Wietrznia, Holy Cross Mts, Poland)
Facies, 2007Co-Authors: Aleksandra VierekAbstract:Wietrznia section is situated between the shallow-water carbonate platform in the Kielce region and the Łysogóry basin. The transitional facies of the Wietrznia Frasnian includes two overlapping types of deposits: (1) thin-bedded dark-coloured limestone-marl alternations similar to the basin facies and (2) coarse-grained detrital limestones. Three lithotypes of limestones were identified: laminated or graded micritic, nodular, and detrital. The petrographic study makes it possible for the recognition of six major microfacies (MF 1 to MF 6). These lithotypes were formed by redeposition in a low- to high-energy environment. Their source material was the stromatoporoid-coral Dyminy reef in the central part of the Kielce region. Storms are considered to be the main agent, which causes in erosion and transport; micritic limestones and distal Tempestites occur together, whereas detrital limestones are associated with proximal Tempestites. Most probably, part of the detrital beds was formed as a result of grain-flow initiated under storm conditions.
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Storm-dominated deposition on a Frasnian carbonate platform margin (Wietrznia, Holy Cross Mts., Poland)
Geological Quarterly, 2007Co-Authors: Aleksandra VierekAbstract:The Wietrznia quarry in Kielce is situated between the shallow-water Devonian carbonate platform in the Kielce region and the deeper Łysogory basin. This palaeogeographic setting affected carbonate sedimentation in Late Devonian times. The transitional facies of the Wietrznia Frasnian comprises two overlapping types of deposits: (1) micritic and marly limestone of shelf basin facies and (2) coarse-grained limestone of fore-reef facies. The first type includes laminated- and graded micritic limestone and nodular limestone. The second includes intraformational conglomerates and breccias, and crinoidal limestone. The limestones in the middle Wietrznia Beds formed within storm wave base in a shallow (possibly only a few tens of metres) sea that deepened eastwards. Storms are likely to have been the main cause of erosion and transport. In the western part of the quarry, proximal Tempestites show evidence of amalgamation and cannibalism as do some high-energy flat-pebble conglomerates. With abating storm winds, finer-grained graded and laminated limestones accumulated. Toward the eastern part of the quarry, the high-energy effects of near-shore storm waves are less evident; the deposits there are transitional or more distal Tempestites.
Lars Stemmerik - One of the best experts on this subject based on the ideXlab platform.
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Tempestite facies variability and storm depositional processes across a wide ramp towards a polygenetic model for hummocky cross stratification
Sedimentology, 2020Co-Authors: Mads E. Jelby, Sten-andreas Grundvåg, Snorre Olaussen, Lars Stemmerik, William HellandhansenAbstract:This is the peer reviewed version of the following article: Jelby, M.E., Grundvag, S.‐A., Helland‐Hansen, W., Olaussen, S. & Stemmerik, L. (2020). Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification. Sedimentology, 67, 742-781, which has been published in final form at https://doi.org/10.1111/sed.12671 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions .
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Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification
Sedimentology, 2019Co-Authors: Mads E. Jelby, Sten-andreas Grundvåg, William Helland-hansen, Snorre Olaussen, Lars StemmerikAbstract:This is the peer reviewed version of the following article: Jelby, M.E., Grundvag, S.‐A., Helland‐Hansen, W., Olaussen, S. & Stemmerik, L. (2020). Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification. Sedimentology, 67, 742-781, which has been published in final form at https://doi.org/10.1111/sed.12671 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions .
Alberto Pérez-lópez - One of the best experts on this subject based on the ideXlab platform.
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Tempestite facies models for the epicontinental Triassic carbonates of the Betic Cordillera (southern Spain)
Sedimentology, 2011Co-Authors: Alberto Pérez-lópez, Fernando Pérez-valeraAbstract:This study focuses on storm deposits in the Muschelkalk facies of the Betic Cordillera (southern Spain) and interprets their deposition mechanisms. Three types of storm deposit are distinguished: (i) pot/gutter casts; (ii) Tempestite beds; and (iii) storm-winnowed deposits. Each deposit provides information about the carbonate platform environment in which it was deposited. The Tempestite models proposed are: (i) the bypass-zone Tempestite model, occurring in a muddy ramp at the epicontinental basin margin. This model is characterized by potholes and gutters that form in a shoreline bypass-zone during storms; (ii) the gradient-current Tempestite model in which frequent Tempestite beds are related to storm gradient currents. Thickness and grain size decrease towards the deep distal ramp; and (iii) the winnowed deposit Tempestite model whereby storm deposits are winnowed and deposited in the same environment with only short lateral transport having occurred. This model evokes more restricted and shallower conditions, lagoons or inland seas. The distribution of all these deposits in the stratigraphic sections studied corroborate the eustatic third-order cycle identified, although the different features of the storm deposits and their positions in each section indicate a subsidence varying in time and space. In the transgressive stage, the margins of the epicontinental basin were a well-developed ramp with potholes and gutters. In contrast, during the high sea-level stage, storm deposits generated Tempestite beds or storm-winnowed deposits in the different areas. The epicontinental carbonate platform with ramp edges evolved into a complex depositional system of coastal and shallow-marine environments with lagoons and restricted inland seas. Thus, the epicontinental platform underwent substantial change from the Late Anisian to the Late Ladinian and this is reflected in its storm deposits.
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Significance of pot and gutter casts in a Middle Triassic carbonate platform, Betic Cordillera, southern Spain
Sedimentology, 2001Co-Authors: Alberto Pérez-lópezAbstract:Pot casts and gutter casts are described for the first time in the lower part of the Majanillos Formation, a Middle Triassic carbonate unit located in the External Zones of the Betic Cordillera (southern Spain). Their identification, as well as their relation to Tempestites, enables the better interpretation of the depositional environments and the shoreline-to-offshore facies transition on the Anisian muddy carbonate ramp of the southern Iberian Massif. The Majanillos Formation contains three members, which become progressively more marly towards the top. Well-preserved pot and gutter casts and thin intercalations of calcarenite, which are interpreted as Tempestites, are abundant in the lowest member. Above the pot and gutter casts, thicker calcarenite beds, which locally contain hummocky cross-stratification, predominate. Bioturbated nodular limestones are prevalent at the top of the member. The remaining succession, which records a long-term Triassic transgressive cycle, consists mostly of fine-grained limestones deposited in very shallow-marine environments. Calcarenitic sediments only accumulated within potholes and gutters in the nearshore. They developed during storms when strong currents transported sediment to the outer shelf, where it was deposited as Tempestite beds. Pot and gutter casts characterize sedimentation in the bypass zone. It is concluded that storm deposits provide important constraints for the interpretation of palaeobathymetry; it is proposed that gutter casts display a trend of increasing width/thickness ratios towards the outer shelf. The identification of these structures in marine successions elsewhere should prove useful in the interpretation of depositional environments.
Mads E. Jelby - One of the best experts on this subject based on the ideXlab platform.
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Tempestite facies variability and storm depositional processes across a wide ramp towards a polygenetic model for hummocky cross stratification
Sedimentology, 2020Co-Authors: Mads E. Jelby, Sten-andreas Grundvåg, Snorre Olaussen, Lars Stemmerik, William HellandhansenAbstract:This is the peer reviewed version of the following article: Jelby, M.E., Grundvag, S.‐A., Helland‐Hansen, W., Olaussen, S. & Stemmerik, L. (2020). Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification. Sedimentology, 67, 742-781, which has been published in final form at https://doi.org/10.1111/sed.12671 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions .
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Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification
Sedimentology, 2019Co-Authors: Mads E. Jelby, Sten-andreas Grundvåg, William Helland-hansen, Snorre Olaussen, Lars StemmerikAbstract:This is the peer reviewed version of the following article: Jelby, M.E., Grundvag, S.‐A., Helland‐Hansen, W., Olaussen, S. & Stemmerik, L. (2020). Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification. Sedimentology, 67, 742-781, which has been published in final form at https://doi.org/10.1111/sed.12671 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions .
Grzegorz Racki - One of the best experts on this subject based on the ideXlab platform.
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Depositional versus ecological control on the conodont distribution in the Lower Frasnian fore-reef facies, Holy Cross Mountains, Poland
Palaeogeography Palaeoclimatology Palaeoecology, 2011Co-Authors: Aleksandra Vierek, Grzegorz RackiAbstract:Abstract Lithofacies and conodont biofacies of reef-slope deposits of the Wietrznia Beds (Lower Frasnian Palmatolepis transitans Zone) were studied in three measured sections at the Wietrznia quarry (Holy Cross Mts. Poland). The diverse reef-derived grained deposits interrupted the background sedimentation that included lime mudstones, deposited largely at 50 to 90 m depths in oxygen-depleted middle slope to toe of slope settings. The mainly storm-controlled proximal gradient is laterally marked by gradual changes from coarse-grained Tempestites, represented by flat-pebble conglomerate fabric, to diluted muddy Tempestites. The mostly sparse polygnathid and mesotaxid–polygnathid biofacies characterize the hemipelagic facies, whilst polygnathid–ancyrodellid biofacies dominates in the event layers. Three-step taphofacies scheme is proposed, distinguishing settled (parautochthonous), residual (winnowed) and displaced (settled from waning currents and/or transported in sediment-gravity flows) conodont element accumulations. The primary ecological signals are still partly preserved in most of the Tempestite-derived assemblages, indicating scarcity of truly residual, lag-like taphofacies. The hydraulic sorting was most effective in the middle-slope setting affected by unidirectional and/or oscillatory flows. Syndepositional mixing was strengthened upslope by an importation of off-reef mesotaxid faunas due to storm surge onto the reef. This reworking pattern as a key factor in biofacies interpretation may be applicable only on a local scale. However, similarly biased conodont signature is probably common in other hurricane-affected carbonate complexes, even if without a disrupting impact on major biofacies belts.
