Accretion Disk Luminosity for Black Holes Surrounded by Dark Matter with Anisotropic Pressure

We investigate the luminosity of the accretion disk of a static black hole surrounded by dark matter with anisotropic pressure. We calculate all basic orbital parameters of test particles in the accretion disk, such as angular velocity, angular momentum, energy, and radius of the innermost circular stable orbit as functions of the dark matter density, radial pressure, and anisotropic parameter, which establishes the relationship between the radial and tangential pressures. We show that the presence of dark matter with anisotropic pressure makes a noticeable difference in the geometry around a Schwarzschild black hole, affecting the radiative flux, differential luminosity, and spectral luminosity of the accretion disk

Palaeoenvironment of the Middle and Upper Neopleistocene at the Gornovo Upper Palaeolithic site (Southern Ural foreland, Russia)

© 2015 Elsevier Ltd and INQUAComplex biostratigraphical methods and radiocarbon dates were used to reconstruct the Middle (late Middle Pleistocene) and Late Neopleistocene (Late Pleistocene) palaeoenvironments covering the Palaeolithic period in the western foreland of the Urals. The Gornovo Palaeolithic settlement is located on the lowest terrace of the Belaya River. From the base to the top, this terrace consists of fluvial and lacustrine deposits of the Belaya horizon (Middle Neopleistocene; 427–364 ka), alluvial and lacustrine deposits of the Larevka horizon (Middle Neopleistocene; 364–334 ka), fluvial and lacustrine deposits of the Tabulda horizon (Late Neopleistocene; 57–24 ka), water-slope deposits of the Kudashevo horizon (Late Neopleistocene; 24–11 ka) and chernozem soil of the Holocene. The small and large mammals, insects, molluscs, and ostracods discovered in the deposits complete the palaeoecological characteristics of these periods. A diverse herbaceous steppe vegetation dominated during the Belaya Interglacial (a mixed coniferous forests with broad-leaved trees occurred in wet areas). The ostracoda species clearly indicate a cooling at the end of this time span. Molluscs inhabited the rivers and shores of freshwater ponds. The large mammals belong to the Middle Pleistocene fauna complex. During Larevka time span vegetation and fauna indicate cold climate conditions. The cold steppe communities typical of the beginning of this period changed gradually into communities that show an increasing role of the taiga. The ostracoda species confirm these cold conditions. Forest-steppe landscapes dominated during the second part of the Tabulda time span. Numerous ostracods as well as molluscs populated the lakes and floodplain basins. Entomological data show that the palaeoenvironment conditions were somewhat cooler than modern environment existing in the Southern Ural foreland. The large mammals of the Gornovo site belong to the Late Palaeolithic complex with the specific presence of Camelus sp. The Gornovo forest-steppe small mammalian fauna developed in cool continental climate conditions when coniferous forests grew in the river valleys and when forest-steppe landscapes dominated in the water interfluves. The artefacts are characteristic of the beginning of the Late Palaeolithic (32–24 ka). The Kudashevo time is correlated with the late Valdai (late Late Pleistocene; 24–11 ka). The herbage-Artemisia-Chenopodiaceae grassland-steppe association covered most of the territory and a Picea forest with Betula and a small quantity of broad-leaved trees grew in wet depressions. The climate at the end of this period became colder. Freshwater and terrestrial molluscs were represented by rare widespread species while the ostracoda species indicate cold conditions

Biostratigraphy of the early Middle Pleistocene of the Southern Fore-Urals

© 2015 Elsevier Ltd and INQUA. A summary of published and unpublished data on the stratigraphy of the early Middle Pleistocene of the Southern Urals region is presented in this paper. It follows previous reviews about the characteristics of the Pleistocene deposits of the easternmost part of Europe. Deposits of different origin, which constitute the regional stratigraphic units, are characterized. Mammalian data form the base for the (bio)stratigraphical subdivision. Fossil mollusca, ostracoda, mammals and pollen are used for the reconstruction of the palaeoenvironmental conditions and the stratigraphical position of the main localities is discussed.The beginning of the early Middle Pleistocene (Minzitarovo time) coincides with a stabilization of the hydrographic network. Palaeontological remains from that period are rare. Pinus-Picea forests with small admixture of broad-leaved species were spread at the beginning of this interval. Later, the role of forests decreased and the role of herbs and Chenopodiaceae increased. Palynological data indicate that the climate was cool during that time. The landscapes of the Baza time were dominated by herbaceous-Artemisia associations and small birch forests with an admixture of broadleaved and coniferous trees and the terminal time was characterized by the wide development of taiga. Ostracods and molluscs are known from those deposits. Ecological composition of the small mammalian faunas indicates forest-steppe conditions for the southern part of this natural zone. Small mammals of that time belong to the Tiraspol faunal assemblage. The climate was warm and dry. The initial Tanyp time was characterized by the development of herbaceous-Artemisia-Chenopodiaceae steppes and broadleaved birch forests, which were subsequently replaced by a dominance of taiga associations, which tolerate cold climatic conditions. Molluscs are represented by rare terrestrial and freshwater species. The assemblage of freshwater ostracods includes cold-resistant species. In the Atasevo time, broadleaved birch forests and meadow-steppes characterized the landscape. The presence of stenothermic-thermophilic ostracods species indicates warm climatic conditions. Molluscs are represented by terrestrial and numerous freshwater species. The small mammalian fauna is characterized by the smaller percentage of Mimomys voles; it post-dates the Baza fauna. The Atasevo fauna is unique because of the occurrence of Arvicola mosbachensis Schmidtgen among the typical early Middle Pleistocene species.At the end of this period during the Chusovskoi timespan, the herbaceous-Artemisia-Chenopodiaceae steppes, which covered spacious open areas, were subsequently replaced by coniferous-birch forests with an admixture of broadleaved trees. Fossil remains are rare. Ostracods represent cold-resistant species indicating that the climate was cold

Biostratigraphy of the early Middle Pleistocene of the Southern Fore-Urals

© 2015 Elsevier Ltd and INQUAA summary of published and unpublished data on the stratigraphy of the early Middle Pleistocene of the Southern Urals region is presented in this paper. It follows previous reviews about the characteristics of the Pleistocene deposits of the easternmost part of Europe. Deposits of different origin, which constitute the regional stratigraphic units, are characterized. Mammalian data form the base for the (bio)stratigraphical subdivision. Fossil mollusca, ostracoda, mammals and pollen are used for the reconstruction of the palaeoenvironmental conditions and the stratigraphical position of the main localities is discussed. The beginning of the early Middle Pleistocene (Minzitarovo time) coincides with a stabilization of the hydrographic network. Palaeontological remains from that period are rare. Pinus–Picea forests with small admixture of broad-leaved species were spread at the beginning of this interval. Later, the role of forests decreased and the role of herbs and Chenopodiaceae increased. Palynological data indicate that the climate was cool during that time. The landscapes of the Baza time were dominated by herbaceous-Artemisia associations and small birch forests with an admixture of broadleaved and coniferous trees and the terminal time was characterized by the wide development of taiga. Ostracods and molluscs are known from those deposits. Ecological composition of the small mammalian faunas indicates forest-steppe conditions for the southern part of this natural zone. Small mammals of that time belong to the Tiraspol faunal assemblage. The climate was warm and dry. The initial Tanyp time was characterized by the development of herbaceous–Artemisia–Chenopodiaceae steppes and broadleaved birch forests, which were subsequently replaced by a dominance of taiga associations, which tolerate cold climatic conditions. Molluscs are represented by rare terrestrial and freshwater species. The assemblage of freshwater ostracods includes cold-resistant species. In the Atasevo time, broadleaved birch forests and meadow-steppes characterized the landscape. The presence of stenothermic–thermophilic ostracods species indicates warm climatic conditions. Molluscs are represented by terrestrial and numerous freshwater species. The small mammalian fauna is characterized by the smaller percentage of Mimomys voles; it post-dates the Baza fauna. The Atasevo fauna is unique because of the occurrence of Arvicola mosbachensis Schmidtgen among the typical early Middle Pleistocene species. At the end of this period during the Chusovskoi timespan, the herbaceous–Artemisia–Chenopodiaceae steppes, which covered spacious open areas, were subsequently replaced by coniferous-birch forests with an admixture of broadleaved trees. Fossil remains are rare. Ostracods represent cold-resistant species indicating that the climate was cold

Quaternary deposits and biostratigraphy in caves and grottoes located in the Southern Urals (Russia)

Bioarchaeolog

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Biostratigraphy of the late Early Pleistocene (Eopleistocene)of the Southern Fore-Urals region (Russia)

© 2019 Elsevier Ltd and INQUA A summary of published and unpublished data on the stratigraphy of the late Early Pleistocene (Eopleistocene)of the Southern Urals region is presented in this paper. The summary follows previous reviews about the characteristics of the Pleistocene deposits of the easternmost part of Europe. The improvement and unification of the regional Quaternary stratigraphic scheme is the main aim of these investigations. In this paper we describe deposits of different origin, which constitute the regional stratigraphic units (Tyulyan, Raevka, Udryak, Khlebodarovka, Dombarovka, Blagovar and Oktyabrsky Horizons), are characterized. During the late Early Pleistocene (Eopleistocene), the Southern Fore-Urals region was characterized by continental climate conditions and by four phases of incisions of the hydrographic network that were related to regional uplift, as well as to the lowering of the base level and the subsequent regression of the Late Akchagylian Sea. Fossil molluscs, ostracods, mammals and pollen are used for the reconstruction of the palaeoenvironmental conditions and the biostratigraphical positions of the main localities. During Raevka, Khlebodarovka and Blagovar times, the climate was cool, and forest-steppe landscapes with prevalent open spaces existed. The climate during the Tyulyan, Udryak, and Dombarovka and Oktyabrsky times was warm, and during these periods, the areas of deciduous and coniferous forests expanded in the forest-steppes. The molluscan fauna of the Early Eopleistocene was a transitional fauna from the Pliocene to the Quaternary because the wet and warm climate, which was favourable to the Pliocene mollusc species, continued in the Southern Fore-Urals during the Early Eopleistocene. The mammalian assemblages are the basis for the biostratigraphical subdivision. The deposits are biostratigraphically correlated to the Lower Eopleistocene on the basis of the appearance of the first unrooted voles Allophaiomys and Prolagurus together with late species of the Mimomys genus. At the end of the Eopleistocene, the unrooted voles Terricola and Lagurina were numerous, the first Microtus appeared, late species of Mimomys were not numerous, and Archidiskodon trogontherii appeared in the mammal faunas of the region. The small mammals of the Tyulyan and Udryak times represent the Odessa faunal assemblage. The mammal fauna of the Oktyabrsky time corresponds to the Tiraspol faunal assemblage. The units are correlated with the Upper Villafranchian – Galerian stages interval in the Western European stratigraphical timescale

Biostratigraphy of the late Early Pleistocene (Eopleistocene)of the Southern Fore-Urals region (Russia)

© 2019 Elsevier Ltd and INQUA A summary of published and unpublished data on the stratigraphy of the late Early Pleistocene (Eopleistocene)of the Southern Urals region is presented in this paper. The summary follows previous reviews about the characteristics of the Pleistocene deposits of the easternmost part of Europe. The improvement and unification of the regional Quaternary stratigraphic scheme is the main aim of these investigations. In this paper we describe deposits of different origin, which constitute the regional stratigraphic units (Tyulyan, Raevka, Udryak, Khlebodarovka, Dombarovka, Blagovar and Oktyabrsky Horizons), are characterized. During the late Early Pleistocene (Eopleistocene), the Southern Fore-Urals region was characterized by continental climate conditions and by four phases of incisions of the hydrographic network that were related to regional uplift, as well as to the lowering of the base level and the subsequent regression of the Late Akchagylian Sea. Fossil molluscs, ostracods, mammals and pollen are used for the reconstruction of the palaeoenvironmental conditions and the biostratigraphical positions of the main localities. During Raevka, Khlebodarovka and Blagovar times, the climate was cool, and forest-steppe landscapes with prevalent open spaces existed. The climate during the Tyulyan, Udryak, and Dombarovka and Oktyabrsky times was warm, and during these periods, the areas of deciduous and coniferous forests expanded in the forest-steppes. The molluscan fauna of the Early Eopleistocene was a transitional fauna from the Pliocene to the Quaternary because the wet and warm climate, which was favourable to the Pliocene mollusc species, continued in the Southern Fore-Urals during the Early Eopleistocene. The mammalian assemblages are the basis for the biostratigraphical subdivision. The deposits are biostratigraphically correlated to the Lower Eopleistocene on the basis of the appearance of the first unrooted voles Allophaiomys and Prolagurus together with late species of the Mimomys genus. At the end of the Eopleistocene, the unrooted voles Terricola and Lagurina were numerous, the first Microtus appeared, late species of Mimomys were not numerous, and Archidiskodon trogontherii appeared in the mammal faunas of the region. The small mammals of the Tyulyan and Udryak times represent the Odessa faunal assemblage. The mammal fauna of the Oktyabrsky time corresponds to the Tiraspol faunal assemblage. The units are correlated with the Upper Villafranchian – Galerian stages interval in the Western European stratigraphical timescale

Palaeoenvironment of the Middle and Upper Neopleistocene at the Gornovo Upper Palaeolithic site (Southern Ural foreland, Russia)

© 2015 Elsevier Ltd and INQUAComplex biostratigraphical methods and radiocarbon dates were used to reconstruct the Middle (late Middle Pleistocene) and Late Neopleistocene (Late Pleistocene) palaeoenvironments covering the Palaeolithic period in the western foreland of the Urals. The Gornovo Palaeolithic settlement is located on the lowest terrace of the Belaya River. From the base to the top, this terrace consists of fluvial and lacustrine deposits of the Belaya horizon (Middle Neopleistocene; 427–364 ka), alluvial and lacustrine deposits of the Larevka horizon (Middle Neopleistocene; 364–334 ka), fluvial and lacustrine deposits of the Tabulda horizon (Late Neopleistocene; 57–24 ka), water-slope deposits of the Kudashevo horizon (Late Neopleistocene; 24–11 ka) and chernozem soil of the Holocene. The small and large mammals, insects, molluscs, and ostracods discovered in the deposits complete the palaeoecological characteristics of these periods. A diverse herbaceous steppe vegetation dominated during the Belaya Interglacial (a mixed coniferous forests with broad-leaved trees occurred in wet areas). The ostracoda species clearly indicate a cooling at the end of this time span. Molluscs inhabited the rivers and shores of freshwater ponds. The large mammals belong to the Middle Pleistocene fauna complex. During Larevka time span vegetation and fauna indicate cold climate conditions. The cold steppe communities typical of the beginning of this period changed gradually into communities that show an increasing role of the taiga. The ostracoda species confirm these cold conditions. Forest-steppe landscapes dominated during the second part of the Tabulda time span. Numerous ostracods as well as molluscs populated the lakes and floodplain basins. Entomological data show that the palaeoenvironment conditions were somewhat cooler than modern environment existing in the Southern Ural foreland. The large mammals of the Gornovo site belong to the Late Palaeolithic complex with the specific presence of Camelus sp. The Gornovo forest-steppe small mammalian fauna developed in cool continental climate conditions when coniferous forests grew in the river valleys and when forest-steppe landscapes dominated in the water interfluves. The artefacts are characteristic of the beginning of the Late Palaeolithic (32–24 ka). The Kudashevo time is correlated with the late Valdai (late Late Pleistocene; 24–11 ka). The herbage-Artemisia-Chenopodiaceae grassland-steppe association covered most of the territory and a Picea forest with Betula and a small quantity of broad-leaved trees grew in wet depressions. The climate at the end of this period became colder. Freshwater and terrestrial molluscs were represented by rare widespread species while the ostracoda species indicate cold conditions

Palaeoenvironment of the Middle and Upper Neopleistocene at the Gornovo Upper Palaeolithic site (Southern Ural foreland, Russia)

© 2015 Elsevier Ltd and INQUA. Complex biostratigraphical methods and radiocarbon dates were used to reconstruct the Middle (late Middle Pleistocene) and Late Neopleistocene (Late Pleistocene) palaeoenvironments covering the Palaeolithic period in the western foreland of the Urals. The Gornovo Palaeolithic settlement is located on the lowest terrace of the Belaya River. From the base to the top, this terrace consists of fluvial and lacustrine deposits of the Belaya horizon (Middle Neopleistocene; 427-364ka), alluvial and lacustrine deposits of the Larevka horizon (Middle Neopleistocene; 364-334ka), fluvial and lacustrine deposits of the Tabulda horizon (Late Neopleistocene; 57-24ka), water-slope deposits of the Kudashevo horizon (Late Neopleistocene; 24-11ka) and chernozem soil of the Holocene. The small and large mammals, insects, molluscs, and ostracods discovered in the deposits complete the palaeoecological characteristics of these periods. A diverse herbaceous steppe vegetation dominated during the Belaya Interglacial (a mixed coniferous forests with broad-leaved trees occurred in wet areas). The ostracoda species clearly indicate a cooling at the end of this time span. Molluscs inhabited the rivers and shores of freshwater ponds. The large mammals belong to the Middle Pleistocene fauna complex. During Larevka time span vegetation and fauna indicate cold climate conditions. The cold steppe communities typical of the beginning of this period changed gradually into communities that show an increasing role of the taiga. The ostracoda species confirm these cold conditions. Forest-steppe landscapes dominated during the second part of the Tabulda time span. Numerous ostracods as well as molluscs populated the lakes and floodplain basins. Entomological data show that the palaeoenvironment conditions were somewhat cooler than modern environment existing in the Southern Ural foreland. The large mammals of the Gornovo site belong to the Late Palaeolithic complex with the specific presence of Camelus sp. The Gornovo forest-steppe small mammalian fauna developed in cool continental climate conditions when coniferous forests grew in the river valleys and when forest-steppe landscapes dominated in the water interfluves. The artefacts are characteristic of the beginning of the Late Palaeolithic (32-24ka). The Kudashevo time is correlated with the late Valdai (late Late Pleistocene; 24-11ka). The herbage-Artemisia-Chenopodiaceae grassland-steppe association covered most of the territory and a Picea forest with Betula and a small quantity of broad-leaved trees grew in wet depressions. The climate at the end of this period became colder. Freshwater and terrestrial molluscs were represented by rare widespread species while the ostracoda species indicate cold conditions