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Xiaoqiao Wan - One of the best experts on this subject based on the ideXlab platform.
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Ostracods from the non marine lower cretaceous interval at liying section of luanping basin north china a stratigraphic correlation
Cretaceous Research, 2021Co-Authors: Zuohuan Qin, Benjamin Sames, Xuejiao Wang, Muhammad Kamran, Xiaoqiao WanAbstract:Abstract Non-marine strata of Lower Cretaceous age in western Liaoning and northern Hebei, North China, are famous for its Jehol Biota, including abundant Ostracods. However, there are still some controversies about the stratigraphic correlation in these regions, for instance, it is still debated whether the interval from the Liying section of Luanping Basin belongs to the Dadianzi Formation or the member 1 of the Xiguayuan Formation. Ostracods act as an important tool for the correlation of the stratigraphy within or between basins. Here we report and illustrate the Ostracods from the Liying section in detail for the first time, and aim to determine the section's stratigraphic correlation. Results show that, the Liying section has a thickness of 157.65 m and can be divided into 33 layers. Ostracods from this section are mainly distributed in the lower and middle part, and 7 genera and 13 species have been preliminarily recognized. These Ostracod species can be summarized as the Cypridea-Limnocypridea-Lycopterocypris Assemblage Zone temporarily. Based on the identified Ostracods, occurrence of other abundant representative fossils of the Jehol Biota, and isotope dating results, the major interval of the Liying section should be assigned to member 1 of the Xiguayuan Formation, and can be correlated with the Yixian Formation from western Liaoning.
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Ostracods of the non marine lower cretaceous dabeigou formation at yushuxia luanping basin north china implications for the early jehol biota age
Cretaceous Research, 2018Co-Authors: Zuohuan Qin, Benjamin Sames, Dermeval Aparecido Do Carmo, Xuri Wang, Feng Wei, Amanda Moreira Leite, Xiaoqiao WanAbstract:Abstract The Dabeigou Formation in the Luanping basin in northern China is well known for its continuous non-marine Lower Cretaceous deposits and the preservation of the early Jehol Biota, including abundant Ostracods. However, the age of the Dabeigou Formation is still disputed. Here, we present a detailed lithostratigraphic analysis and Ostracod biostratigraphy of the newly exposed Yushuxia section of the Luanping basin. At this locality, the Dabeigou Formation can be subdivided into 46 layers, which is mainly composed of grey to dark grey fine clastics of semi-deep lake face. Ostracod analysis on samples from the Dabeigou Formation revealed 14 species of nine genera. Biostratigraphically, the Ostracods of the Dabeigou Formation belong to the Luanpingella-Torinina-Eoparacypris Zone. Most of the species range from the latest Jurassic to the earliest Cretaceous. However, some species show a closer relation with Ostracods from the upper Lower Cretaceous Dadianzi Formation (upper Hauterivian to Barremian), the Yixian Formation (lower Aptian) of North China, and the Purbeck–Wealden Group (uppermost Tithonian to lowermost Aptian) of Britain. Combined with the biostratigraphy of other fossils and the U-Pb age, it is suggested that the Ostracod fauna of the Dabeigou Formation and the origin of early Jehol Biota might be of Early Cretaceous age entirely.
Zuohuan Qin - One of the best experts on this subject based on the ideXlab platform.
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Ostracods from the non marine lower cretaceous interval at liying section of luanping basin north china a stratigraphic correlation
Cretaceous Research, 2021Co-Authors: Zuohuan Qin, Benjamin Sames, Xuejiao Wang, Muhammad Kamran, Xiaoqiao WanAbstract:Abstract Non-marine strata of Lower Cretaceous age in western Liaoning and northern Hebei, North China, are famous for its Jehol Biota, including abundant Ostracods. However, there are still some controversies about the stratigraphic correlation in these regions, for instance, it is still debated whether the interval from the Liying section of Luanping Basin belongs to the Dadianzi Formation or the member 1 of the Xiguayuan Formation. Ostracods act as an important tool for the correlation of the stratigraphy within or between basins. Here we report and illustrate the Ostracods from the Liying section in detail for the first time, and aim to determine the section's stratigraphic correlation. Results show that, the Liying section has a thickness of 157.65 m and can be divided into 33 layers. Ostracods from this section are mainly distributed in the lower and middle part, and 7 genera and 13 species have been preliminarily recognized. These Ostracod species can be summarized as the Cypridea-Limnocypridea-Lycopterocypris Assemblage Zone temporarily. Based on the identified Ostracods, occurrence of other abundant representative fossils of the Jehol Biota, and isotope dating results, the major interval of the Liying section should be assigned to member 1 of the Xiguayuan Formation, and can be correlated with the Yixian Formation from western Liaoning.
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Ostracods of the non marine lower cretaceous dabeigou formation at yushuxia luanping basin north china implications for the early jehol biota age
Cretaceous Research, 2018Co-Authors: Zuohuan Qin, Benjamin Sames, Dermeval Aparecido Do Carmo, Xuri Wang, Feng Wei, Amanda Moreira Leite, Xiaoqiao WanAbstract:Abstract The Dabeigou Formation in the Luanping basin in northern China is well known for its continuous non-marine Lower Cretaceous deposits and the preservation of the early Jehol Biota, including abundant Ostracods. However, the age of the Dabeigou Formation is still disputed. Here, we present a detailed lithostratigraphic analysis and Ostracod biostratigraphy of the newly exposed Yushuxia section of the Luanping basin. At this locality, the Dabeigou Formation can be subdivided into 46 layers, which is mainly composed of grey to dark grey fine clastics of semi-deep lake face. Ostracod analysis on samples from the Dabeigou Formation revealed 14 species of nine genera. Biostratigraphically, the Ostracods of the Dabeigou Formation belong to the Luanpingella-Torinina-Eoparacypris Zone. Most of the species range from the latest Jurassic to the earliest Cretaceous. However, some species show a closer relation with Ostracods from the upper Lower Cretaceous Dadianzi Formation (upper Hauterivian to Barremian), the Yixian Formation (lower Aptian) of North China, and the Purbeck–Wealden Group (uppermost Tithonian to lowermost Aptian) of Britain. Combined with the biostratigraphy of other fossils and the U-Pb age, it is suggested that the Ostracod fauna of the Dabeigou Formation and the origin of early Jehol Biota might be of Early Cretaceous age entirely.
Peter Frenzel - One of the best experts on this subject based on the ideXlab platform.
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spatial distribution and ecology of the recent Ostracoda from tangra yumco and adjacent waters on the southern tibetan plateau a key to palaeoenvironmental reconstruction
Limnologica, 2016Co-Authors: Lailah Gifty Akita, Peter Frenzel, Junbo Wang, Nicole Borner, Ping PengAbstract:We elucidate the ecology of Recent Ostracoda from a deep brackish lake, Tangra Yumco (30°45′—31°22′N and 86°23′—86°49′E, 4595 m a.s.l.) and adjacent waters on the southern Tibetan Plateau. Ostracod associations (living and empty valves) in sixty-six sediment samples collected from diverse aquatic habitats (lakes, estuary-like water and lagoon-like water waters, rivers, ponds and springs) were quantitatively assessed. Eleven Recent Ostracoda were found (nine living and two as empty valves only). Cluster analysis established two significant (p < 0.05) habitat specific associations; (i) Leucocytherella sinensis, Limnocythere inopinata, Leucocythere? dorsotuberosa, Fabaeformiscandona gyirongensis and Candona xizangensis are lacustrine fauna. (ii) Tonnacypris gyirongensis, Candona candida, Ilyocypris sp., Heterocypris incongruens and Heterocypris salina are temporary water species. Ostracod distribution and abundance are significantly (p < 0.05) correlated to physico-chemical variables. The first two axes of a canonical correspondence analysis (CCA) explain 30.9% of the variation in the species abundance data. Conductivity and habitat types are the most influential ecological factors explaining the presence and abundance of Ostracods. Spearman correlation analysis reveals that: (i) Two species, L.? dorsotuberosa (r = 0.25) and L. inopinata (r = 0.36) have a significant positive correlation with conductivity while one species, T. gyirongensis (r = −0.68) displays a significant negative correlation with conductivity. Limnocythere inopinata correlates significantly positive (r = 0.37) with alkalinity. Fabaeformiscandona gyirongensis correlates significantly positive (r = 0.28) with water depth. Key indicator living assemblages are: (i) L. sinensis dominates Ca-depleted brackish waters although ubiquitously distributed; (ii) L.? dorsotuberosa dwells in fresh to brackish waters; (iii) L. inopinata predominates in mesohaline to polyhaline waters; (iv) F. gyirongensis inhabits exclusively brackish-lacustrine deeper waters; (v) C. candida populates freshwaters; (vi) T. gyirongensis and Ilyocypris sp. are restricted to shallow temporary waters; (vii) H. incongruens occurs in ponds. Water depth indicators are F. gyirongensis and L.? dorsotuberosa, useful in Ostracod assemblages for palaeo-water depth reconstruction. Our results expand the knowledge of the ecological significance of Recent Tibetan Ostracoda ecology. This is a new insight on habitat chacteristics of both living assemblages and sub-Recent associations of Ostracods in mountain aquatic ecosystems. The new modern Ostracod dataset can be used for the quantitative reconstruction of past environmental variables (e.g., conductivity) and types of water environment. The key indicator Ostracods are relevant in palaeolimnological and climate research on the Tibetan Plateau.
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Ostracoda from inland waterbodies with saline influence in central germany implications for palaeoenvironmental reconstruction
Palaeogeography Palaeoclimatology Palaeoecology, 2015Co-Authors: Anna Pint, Peter Frenzel, Julia Franke, Thomas Daniel, Antonia Burghardt, Benjamin Funai, Kristina Lippold, Gerhardt Daut, Volker WennrichAbstract:Abstract As a necessary precursor to reconstructing the palaeoenvironmental conditions likely to be temporarily influenced by salt bearing ground waters, modern sites of Central Germany, known from the literature to be continental salt water localities, were investigated for their Ostracod faunas. Analysing their associations enables the test of several methods in palaeoenvironmental analysis based on Ostracods. In total, 54 Ostracod taxa are documented. One species, Microdarwinula zimmeri, is new for the area. Interesting is the historical occurrence of Cyprideis torosa and Cytheromorpha fuscata, typically regarded as indicators of brackish water. The draining of wetlands has led to the disappearance of many former inland salt sites so that only a few of the sampled water bodies still show slightly elevated salinity (oligohaline range). The most important factors for the distribution of Ostracod associations are groundwater influence, turbidity and ecological stability, whereas the type of dominating ions is of lesser importance because of time-averaging using taphocoenoses from surface sediments in our study. The relative proportion of ecological groups of Ostracods appears to be the best tool for reconstructing past habitat types. The newly established Ostracod Permanence Index and Ostracod Turbulence Index allow the recognition of the influx of ground and surface waters, perennial habitats and flowing waters. A test of the Mutual Ostracod Temperature Range (MOTR) method demonstrates its capability to reconstruct, with a precision of +/− 2 °C, the mean July and January air temperatures for the time interval 2002–2012. Additionally, the study contributes to the poorly known Recent distribution of Ostracods in Central Germany.
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Ostracoda crustacea as indicators of subaqueous mass movements an example from the large brackish lake tangra yumco on the southern tibetan plateau china
Palaeogeography Palaeoclimatology Palaeoecology, 2015Co-Authors: Lailah Gifty Akita, Peter Frenzel, Junbo Wang, Torsten Haberzettl, Thomas Kasper, Klaus ReicherterAbstract:Abstract A conceptual model of subaquaeous mass movements and Ostracod distribution in lacustrine sediment event layers was tested. Integrated methods (geophysical, sedimentological and microfossil analyses) were performed on a short sediment core retrieved from 220 m water depth in the large brackish lake Tangra Yumco on the southern Tibetan Plateau, central Asia. The event layers of the core and their underlying and overlying sediments were investigated. Four major event layers composed of sandy silt with graded bedding are interpreted as turbidites. The fifth layer consisting of fine sand and silt and without graded bedding is characterized as a debrite. The Ostracods, small bivalved aquatic crustaceans, identified are Leucocytherella sinensis Huang, 1982, Leucocythere ? dorsotuberosa Huang, 1982, Limnocythere inopinata (Baird, 1843) and Fabaeformiscandona gyirongensis (Huang, 1982). Ostracod evidence is a good proxy for the evaluation of massive sediment event layers formed by subaqueous mass movements. Four assumptions of a conceptual model were confirmed: (i) fine grained sediments of event layers (turbidite deposits) contain very low numbers of Ostracods compared to the underlying and overlying sediments; (ii) Ostracods are sorted according to size and display high abundance and high proportion of adult valves of Leucocytherella sinensis at the base of event layers; (iii) a relatively low number of carapaces is present within the event layers; and (iv) the recolonization of newly event-generated habitats by pioneer assemblages transforming into pre-event association gradually.
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the use of Ostracods from marginal marine brackish waters as bioindicators of modern and quaternary environmental change
Palaeogeography Palaeoclimatology Palaeoecology, 2005Co-Authors: Peter Frenzel, Ian BoomerAbstract:Abstract Ostracoda (microscopic, aquatic Crustacea) from brackish waters have a great potential for ecological monitoring and palaeoenvironmental analyses in highly variable environments. This has been proven in many articles during recent decades but their potential has yet to be fully developed or utilised. The analysis of Ostracod assemblage composition, species distributions, eco-phenotypic variability and the analysis of stable isotopes and trace elements in Ostracod shells provide valuable information on present and past water salinity, temperature and chemistry, hydrodynamic conditions, substrate characteristics, climate, sea level variations, oxygen and nutrient availability. This article provides an overview on the application of Ostracods from brackish waters for palaeoenvironmental reconstruction in the Quaternary and for environmental studies in present day environments.
Alain Préat - One of the best experts on this subject based on the ideXlab platform.
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Ostracods and rock facies across the emsian eifelian boundary at couvin dinant synclinorium belgium
Palaeobiodiversity and Palaeoenvironments, 2017Co-Authors: Jean-georges Casier, Sébastien Maillet, Alain PréatAbstract:A moderately rich Ostracod fauna is reported from the upper part of the St. Joseph Formation (Fm), the Eau Noire Fm and the lower part of the Couvin Fm in the Eau Noire section located nearby Couvin. The section that crosses the Emsian/Eifelian boundary belongs entirely to the Couvinian historical stage. The Ostracod fauna observed appertains to the Eifelian Mega-Assemblage and is indicative, in the Eau Noire Fm and in the Couvin Fm, of continuous shallow open-marine environments close to the fair-weather wave-base. The sampling and the number of Ostracods extracted from the St. Joseph Fm are not sufficient to make environmental inferences and the study does not demonstrate an abnormal change in the Ostracod fauna neither in relation with the Eau Noire Fm/Couvin Fm boundary, nor in relation with the Emsian/Eifelian boundary. The Ostracods present near the Emsian/Eifelian boundary are mentioned for the first time in the southern border of the Dinant Synclinorium and they display close relations with the Eifel Mountains (Germany) and the Holy Cross Mountains (Poland).
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Ostracods and facies of the Early and Middle Frasnian at Devils Gate in Nevada: Relationship to the Alamo Event
2015Co-Authors: Ivan Berra, Ewa Olempska, Charles Sandberg, Alain PréatAbstract:In order to document the Alamo Event and to investigate its influence on shallow−marine environments, we undertook a study of Ostracods, conodonts, and analysis of the sedimentology of the lower member of the type Devils Gate Limestone. Six major carbonate microfacies (MF1–MF6) ranging from open−marine environments below storm wave base to pre−evaporitic supratidal lagoons were recognized. The sedimentological study detected no important sedimentological changes during the Alamo Event; only an influx of detrital material and lithoclasts indicate that an unusual event had oc− curred. Ostracods are generally rare or absent in the lower member of the Devils Gate Limestone, and only 2,000 cara− paces, valves and fragments were extracted; from these some 26 taxa were identified. Two new species, Voronina? eureka and Serenida dorsoplicata are proposed. The Ostracods belong to the Eifelian Mega−Assemblage and their distribution was influenced by strong salinity variations. Because of the rarity and low diversity of Ostracods and conodonts in sam− ples collected from the lower part of the lower member of the Devils Gate Limestone it is not adequate to demonstrate conclusively an extinction event close to the Alamo Event Bed. Nevertheless the greater abundance and diversity of Ostracods above this bed seems to indicate that the Alamo Event did not result in significant extinction of Ostracod taxa in this shallow water setting. The Ostracod fauna present in the lower member of the Devils Gate Limestone suggests fauna
Benjamin Sames - One of the best experts on this subject based on the ideXlab platform.
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Ostracods from the non marine lower cretaceous interval at liying section of luanping basin north china a stratigraphic correlation
Cretaceous Research, 2021Co-Authors: Zuohuan Qin, Benjamin Sames, Xuejiao Wang, Muhammad Kamran, Xiaoqiao WanAbstract:Abstract Non-marine strata of Lower Cretaceous age in western Liaoning and northern Hebei, North China, are famous for its Jehol Biota, including abundant Ostracods. However, there are still some controversies about the stratigraphic correlation in these regions, for instance, it is still debated whether the interval from the Liying section of Luanping Basin belongs to the Dadianzi Formation or the member 1 of the Xiguayuan Formation. Ostracods act as an important tool for the correlation of the stratigraphy within or between basins. Here we report and illustrate the Ostracods from the Liying section in detail for the first time, and aim to determine the section's stratigraphic correlation. Results show that, the Liying section has a thickness of 157.65 m and can be divided into 33 layers. Ostracods from this section are mainly distributed in the lower and middle part, and 7 genera and 13 species have been preliminarily recognized. These Ostracod species can be summarized as the Cypridea-Limnocypridea-Lycopterocypris Assemblage Zone temporarily. Based on the identified Ostracods, occurrence of other abundant representative fossils of the Jehol Biota, and isotope dating results, the major interval of the Liying section should be assigned to member 1 of the Xiguayuan Formation, and can be correlated with the Yixian Formation from western Liaoning.
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Ostracods of the non marine lower cretaceous dabeigou formation at yushuxia luanping basin north china implications for the early jehol biota age
Cretaceous Research, 2018Co-Authors: Zuohuan Qin, Benjamin Sames, Dermeval Aparecido Do Carmo, Xuri Wang, Feng Wei, Amanda Moreira Leite, Xiaoqiao WanAbstract:Abstract The Dabeigou Formation in the Luanping basin in northern China is well known for its continuous non-marine Lower Cretaceous deposits and the preservation of the early Jehol Biota, including abundant Ostracods. However, the age of the Dabeigou Formation is still disputed. Here, we present a detailed lithostratigraphic analysis and Ostracod biostratigraphy of the newly exposed Yushuxia section of the Luanping basin. At this locality, the Dabeigou Formation can be subdivided into 46 layers, which is mainly composed of grey to dark grey fine clastics of semi-deep lake face. Ostracod analysis on samples from the Dabeigou Formation revealed 14 species of nine genera. Biostratigraphically, the Ostracods of the Dabeigou Formation belong to the Luanpingella-Torinina-Eoparacypris Zone. Most of the species range from the latest Jurassic to the earliest Cretaceous. However, some species show a closer relation with Ostracods from the upper Lower Cretaceous Dadianzi Formation (upper Hauterivian to Barremian), the Yixian Formation (lower Aptian) of North China, and the Purbeck–Wealden Group (uppermost Tithonian to lowermost Aptian) of Britain. Combined with the biostratigraphy of other fossils and the U-Pb age, it is suggested that the Ostracod fauna of the Dabeigou Formation and the origin of early Jehol Biota might be of Early Cretaceous age entirely.
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Ostracods from the marginal coastal lower cretaceous aptian of the central tunisian atlas north africa paleoenvironment biostratigraphy and paleobiogeography
Revue de Micropaléontologie, 2015Co-Authors: Khaled Trabelsi, Benjamin Sames, Amal Salmouna, Enelise Katia Piovesan, Soumaya Ben Rouina, Yassin Houla, Jamel Touir, Mohamed SoussiAbstract:Abstract This work provides the first detailed taxonomic study of Ostracod species from the Lower Cretaceous (Aptian) marginal coastal deposits of the Central Tunisian Atlas, the Kebar Formation, as well as biostratigraphic, paleoecological and paleobiogeographic implications. The Ostracod fauna provides new insights into the depositional environment and biostratigraphic framework of the Kebar Formation, and is represented mainly by freshwater and brackish-water species among them, Perissocytheridea tunisiatlasica nov. sp., is newly described. The environmental setting of this formation comprises marginal-littoral conditions in its lower part, thus not exclusively non-marine/continental as assumed previously. The Ostracod associations from the studied locality, Jebel Ksaira, indicate a minimum age of Early Aptian as recently attributed to the lower member of the Kebar Formation based on charophytes (presence of Late Barremian to Early Aptian Globator maillardii var. biutricularis Vicente and Martin-Closas, 2012), whereas an Early Albian age had been previously assigned to the Jebel Kebar site. The relative sea-level fall documented in the lower member of the Kebar formation at Jebel Ksaira might correspond to the 3rd order cycle major eustatic sea-level fall event starting at the base of the Aptian. Paleobiogeographically, the non-marine Ostracod fauna newly discovered in the Kebar Formation shows some affinities to contemporaneous faunas of southern and western Europe, e.g. that of the uppermost Weald Clay Group of southern England (Cypridea fasciata subzone of Horne, 1995), West Africa, and possibly to eastern South America (Brazil). Hence, the studied Ostracods further support the hypothesis of supraregional faunal exchange by passive Ostracod dispersal during the Early Cretaceous – between Europe and Northern Africa on the one hand, and eastern South America/western Africa and North Africa on the other hand. This leads to the hypothesis that the Peri-Tethyan islands could have worked as effective bridges for non-marine Ostracods to become widely dispersed passively by “island-hopping” of larger animals and thus, ultimately, facilitated intercontinental faunal exchanges between South America and Europe – potentially even Asia – via North Africa during the Early Cretaceous.
