scholarly journals Palynological profile and depositional environment of the Ishim formation (upper Miocene) in Tobol-Ishim interfluve, Western Siberia

2019 ◽  
Vol 27 (6) ◽  
pp. 103-123
Author(s):  
O. B. Kuzmina ◽  
I. V. Khazina ◽  
P. V. Smirnov ◽  
A. O. Konstantinov ◽  
A. R. Agatova
Keyword(s):  
Late Pleistocene ◽  
Organic Substance ◽  
Late Miocene ◽  
Depositional Environment ◽  
Western Siberia ◽  
Ice Age ◽  
Quaternary Sediments ◽  
Upper Miocene ◽  
Neogene Sediments ◽  
First Time

For the first time some outcrops of the Upper Miocene Ishim Formation on the south of Tyumen Area near Pyatkovo, Masali and Bigila villages are studied by palynological method in detail. A series of mineralogical analyzes of these sediments and radiocarbon analysis of the Quaternary sediments overlying the Ishim Formation are done. Four palynocomplexes (PC) are established in the Ishim Formation: PC1 with Botryococcus; PC2 with Botryococcus, Sigmopollis; PC3 with Alnus, Polypodiaceae, Botryococcus, Sigmopollis; PC4 with Betula, Alnus, Corylus. The layers with PC1, PC2 и PC3 are traced in two outcrops near Masali and Bigila Villages. PC4 is revealed from the sands and aleuropelits of the outcrop near Pyatkovo Village, it is characterized by a significant content of diverse pollen of temperate termophylic broad-leafed taxa and by the presence of rare typical Miocene elements (Таxodiaceae, Nyssa, Tsuga). The PC3 and PC4 are compared with the complexes well known from the Neogene sediments of Western Siberia. PC5 with Betula, Herbae, Fungi is revealed from the bedded silts overlying the Ishim Formation in Masali outcrop. Previously, these sediments were attributed to the Late Miocene Pavlodar Formation. The composition and the structure of PC5 allowed making an assumption about Quaternary age of the enclosing sediments. Radiocarbon analysis of the organic substance from the silts showed, that these sediments were accumulated in the Late Pleistocene (Sartan Ice Age). For the first time the information about microphytoplankton (Botryococcus, Pediastrum, Zygnemataceae, Sigmopollis) and other nonpollen palynomorphs, contained in Ishim Formation (Upper Miocene) and in Pleistocene sediments, is given. On palynological data, some stages of development of the Late Miocene Ishim Basin and the type of vegetation surrounding this basin are considered. The depositional environment of Pleistocene sediments (Masali outcrop) is reconstructed.

scholarly journals The mesolithic Baigara human: mineralogical-geochemical studies, paleoecological reconstructions and history of early human migrations to Western Siberia

2021 ◽  
Vol 5 ◽  
pp. 5-26
Author(s):  
V. I. Silaev ◽  
◽  
P. A. Kosintsev ◽  
V. N. Filippov ◽  
D. V. Kiseleva ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Western Siberia ◽  
Modern Human ◽  
Human Bone ◽  
History Of ◽  
Geochemical Studies ◽  
First Time ◽  
Paleoecological Reconstructions ◽  
Early Human

A modern human bone of the Mesolithic age, found for the first time in Western Siberia, was studied by the number of mineralogical-geochemical methods. Based on the results obtained, the conclusions about paleoecology, food types, and history of human migrations in the Late Pleistocene — Holocene in Siberia presented

scholarly journals Lithological and geomorphological indicators of glacial genesis of the upper Quaternary strata in the lower courses of the Nadym River

2019 ◽  
Author(s):  
Oleg Sizov ◽  
Anna Volvakh ◽  
Andrey Vishnevskiy ◽  
Andrey Soromotin ◽  
Evgeny Abakumov
Keyword(s):  
Environmental History ◽  
Western Siberia ◽  
Quaternary Sediments ◽  
Glacial Origin ◽  
Digital Terrain ◽  
Terrain Models ◽  
Glacial Processes ◽  
First Time ◽  
Petrographic Study ◽  
Quartz Grains

Abstract. Analysing the genesis of Quaternary sediments is important for understanding the glaciation history and development of marine sediments in the northern part of the Western Siberia. The key features of sedimentation and landform formation have been characterized for the first time in an example of a lithological column from the lower sources of the Nadym River. A comprehensive analysis was performed on the lithological, petrographic, and geomorphological data from the upper stratum of Quaternary sediments of the column. Based on the shape and morphology of quartz grains, some features of glacial processes for some layers of the studied sections were identified and analysed with special attention to the environmental history. A petrographic study of the boulder samples was carried out, which showed that the majority of samples are boulders of glacial origin according to their shape and texture. For the first time, digital terrain models were applied to study of the key plot where the lithological column is situated, which made it possible to identify the specific terrain areas that were most likely formed by glaciation. It is suggested that extensive lacustrine-alluvial plains existed in the Nadym River Basin, which was represented by postglacial sites. Such a concept provides a lithological basis for understanding the reasons for the formation of the present and recently formed environments and landforms. Therefore, it could be possible that local glaciation in the region of the Nadym River's lower course had an effect on the formation of the stratification of the layers of Quaternary origin.

scholarly journals The presence of marin Pliocene sendiments in the Mesohellenic Trough (Pramoritsa banks, Grevena, Greece)

2018 ◽  
Vol 34 (2) ◽  
pp. 603
Author(s):  
Ι. ΦΟΥΝΤΟΥΛΗΣ ◽  
Α. ΜΑΡΚΟΠΟΥΛΟΥ-ΔΙΑΚΑΝΤΩΝΗ ◽  
Α. ΜΠΑΚΟΠΟΥΛΟΥ ◽  
Ε. ΜΩΡΑΪΤΗ ◽  
Μ. Ρ. ΜΙΡΚΟΥ ◽  
...  
Keyword(s):  
Late Miocene ◽  
Depositional Environment ◽  
Systematic Sampling ◽  
Early Pliocene ◽  
Upper Miocene ◽  
Marine Facies ◽  
River Banks

Detailed lithostratigraphic study of the postalpine deposits that build Pramoritsa river banks - tributary of Aliakmonas river- north of Grevena (Greece), showed that the marine molassic deposition did not cease in the Upper Miocene but continued in the Lower Pliocene, too. Systematic sampling revealed abundant pelagic and benthic fossils, the presence of which {Bulimina exilis, Bulimina costata, Neogloboquadrina acostaensis, Globigerinella pseudobesa, Globoquadrina venezuelana, Neoeponides schreibersii, Pulleniatina obliquiloculata, Dorothia gibbosa) proves that marine facies went on, at least, until the Lower Pliocene and that the depositional environment was characterized as coastal with warm waters. According to the Nannoplankton flora correlated with standard nannoplankton -zones-subzones NNllb Amaurolithus delicatus, Discoaster quinqueramus) and NN13 (Ceratolithus rugosus) of MARTINI, 1971 and OKADA & BUKRY, 1980 during the Late Miocene -Early Pliocene. Besides, some characteristics of the Pliocene sediments are described, based on macro- and microscopic observations.

scholarly journals Dinoflagellate cysts from the Pannonian (late Miocene) "white marls" in Pécs-Danitzpuszta, southern Hungary

2021 ◽  
Vol 151 (3) ◽  
pp. 267-274
Author(s):  
Krešimir Krizmanić ◽  
Krisztina Sebe ◽  
Imre Magyar
Keyword(s):  
Late Miocene ◽  
Depositional Environment ◽  
Middle Miocene ◽  
Dinoflagellate Cysts ◽  
Middle Segment ◽  
Lake Pannon ◽  
Dinoflagellate Cyst ◽  
Upper Miocene ◽  
Reference Section

Dinoflagellate-cyst based biostratigraphy is an important tool in the stratigraphical subdivision and correlation of the Neogene Lake Pannon deposits. A total of 66 palynological samples were investigated from the Pannonian (upper Miocene) marl succession exposed in the Pécs-Danitzpuszta sand pit in order to evaluate the biostratigraphical assignment and constrain the age of the strata. Earlier attempts to recover dinoflagellate cysts from this important reference section had failed. In our material, six samples contained well-preserved palynomorphs. One sample from the lower part of the succession (D25) contained a probably reworked middle Miocene assemblage. Samples from the middle segment of the succession (D3, D2, D1) indicate the Pontiadinium pecsvaradensis Zone (ca. 10.8 to 10.6 Ma). Samples from the top of the marl (D219, D221) did not give additional stratigraphic information (P. pecsvaradensis Zone or younger). The palynofacies of samples D3 to D221 indicates a relatively distal, calm, occasionally oxygen-deficient, probably deep depositional environment.

Palynological Profile and Depositional Environment of the Ishim Formation (Upper Miocene) in Tobol–Ishim Interfluve, Western Siberia

2019 ◽  
Vol 27 (6) ◽  
pp. 707-727
Author(s):  
O. B. Kuzmina ◽  
I. V. Khazina ◽  
P. V. Smirnov ◽  
A. O. Konstantinov ◽  
A. R. Agatova
Keyword(s):  
Depositional Environment ◽  
Western Siberia ◽  
Upper Miocene

Palaeolithic Cave Art at Creswell Crags in European Context

2007 ◽  
Keyword(s):  
Late Pleistocene ◽  
Rock Art ◽  
Ice Age ◽  
Upper Palaeolithic ◽  
Southern France ◽  
European Context ◽  
The World ◽  
Cave Art ◽  
Illustrated Book

Cave art is a subject of perennial interest among archaeologists. Until recently it was assumed that it was largely restricted to southern France and northern Iberia, although in recent years new discoveries have demonstrated that it originally had a much wider distribution. The discovery in 2003 of the UK's first examples of cave art, in two caves at Creswell Crags on the Derbyshire/Nottinghamshire border, was the most surprising illustration of this. The discoverers (the editors of the book) brought together in 2004 a number of Palaeolithic archaeologists and rock art specialists from across the world to study the Creswell art and debate its significance, and its similarities and contrasts with contemporary Late Pleistocene ("Ice Age") art on the Continent. This comprehensively illustrated book presents the Creswell art itself, the archaeology of the caves and the region, and the wider context of the Upper Palaeolithic era in Britain, as well as a number of up-to-date studies of Palaeolithic cave art in Spain, Portugal, France, and Italy which serve to contextualize the British examples.

scholarly journals An exceptionally preserved conulariid from Ordovician erratics of Northern European Lowlands

PalZ ◽  
2021 ◽  
Author(s):  
Consuelo Sendino ◽  
Martin M. Bochmann
Keyword(s):  
Internal Structure ◽  
Late Pleistocene ◽  
Point Of View ◽  
Three Dimensions ◽  
Northern European ◽  
Current Location ◽  
Transport Direction ◽  
First Time ◽  
Erratic Boulder

AbstractA conulariid preserved in three dimensions from Ordovician fluvioglacial erratics of the Northern European Lowlands (North German Plain) is described under open nomenclature. It is assigned to the genus Conularia with similarities to Baltoscandian conulariids. The lithology of the erratic boulder and fauna contained in it provide important information on the origin and transport direction of the sediment preserved in a kame from the Saalian glaciation. This paper deals with the site of origin of the boulder in Baltoscandia analysing the comprised palaeofauna, from a palaeostratigraphic and palaeogeographic point of view, from its deposition in Ordovician times until its arrival at its current location in the Late Pleistocene. It also reveals for the first time the internal structure of the conulariid aperture.

Emergence of critical climate states during the Pleistocene

2021 ◽  
Author(s):  
Nicholas Golledge
Keyword(s):  
Dynamical Systems ◽  
Late Pleistocene ◽  
Dominant Frequency ◽  
Climate System ◽  
Ice Age ◽  
Early Pleistocene ◽  
Glacial Cycles ◽  
Pleistocene Climate ◽  
System Nodes ◽  
Systems Framework

<p>During the Pleistocene (approximately 2.6 Ma to present) glacial to interglacial climate variability evolved from dominantly 40 kyr cyclicity (Early Pleistocene) to 100 kyr cyclicity (Late Pleistocene to present). Three aspects of this period remain poorly understood: Why did the dominant frequency of climate oscillation change, given that no major changes in orbital forcing occurred? Why are the longer glacial cycles of the Late Pleistocene characterised by a more asymmetric form with abrupt terminations? And how can the Late Pleistocene climate be controlled by 100 kyr cyclicity when astronomical forcings of this frequency are so much weaker than those operating on shorter periods? Here we show that the decreasing frequency and increasing asymmetry that characterise Late Pleistocene ice age cycles both emerge naturally in dynamical systems in response to increasing system complexity, with collapse events (terminations) occuring only once a critical state has been reached. Using insights from network theory we propose that evolution to a state of criticality involves progressive coupling between climate system 'nodes', which ultimately allows any component of the climate system to trigger a globally synchronous termination. We propose that the climate state is synchronised at the 100 kyr frequency, rather than at shorter periods, because eccentricity-driven insolation variability controls mean temperature change globally, whereas shorter-period astronomical forcings only affect the spatial pattern of thermal forcing and thus do not favour global synchronisation. This dynamical systems framework extends and complements existing theories by accomodating the differing mechanistic interpretations of previous studies without conflict.</p>

ISOTOPE-GEOCHEMICAL FEATURES OF AUTHENIC CARBONATES OF THE YU1 PRODUCING HORIZON OF THE VERKH-TARSKOYE OIL FIELD (SOUTH OF WESTERN SIBERIA)

2020 ◽  
pp. 20-28
Author(s):  
L. G. Vakulenko ◽  
◽  
O. D. Nikolenko ◽  
D. A. Novikov ◽  
P. A. Yan ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Carbonate Rocks ◽  
Western Siberia ◽  
Oil Field ◽  
Third Generation ◽  
The Third ◽  
First Time ◽  
Different Sources ◽  
Sources Of Co2 ◽  
Comprehensive Study

A comprehensive study of the composition of sand and silt deposits of the Yu1 horizon of the Vasyuganskaya Formation upper part of the Verkh-Tarskoye oil field has been carried out. Associations of authigenic minerals have been determined in their cement, among which the calcite is the most widespread. According to petrographic parameters, three generations of calcite have been identified for which detailed isotopicgeochemical and ultramicroscopic studies were carried out for the first time. Wide and multi directional changes in the isotopic composition of carbon and oxygen and in the chemical composition of carbonate minerals were recorded, they indicate significant variations in the conditions of diagenesis and catagenesis, primarily temperature, and different sources of CO2. Significant variations in the isotopic composition of formation waters and its relationship with the isotopic composition of carbonates have been established. Thus, a narrow interval of close δ13C values was revealed, amounting to –10.5 to –9.1 ‰ in the formation waters of group II, and from –10.7 to –9.1 ‰ in calcites of the third generation. The source of CO2 in this system should be considered a carbon dioxide, which is formed in the process of metamorphism of carbonate rocks of the Paleozoic age.

Sign in / Sign up

Export Citation Format

Share Document