continental deposits
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2021 ◽  
pp. 1-11
Author(s):  
Martín D. Ezcurra ◽  
Saswati Bandyopadhyay ◽  
Kasturi Sen

Abstract The fossil record of Early Triassic diapsids is very important to understand how the end-Permian mass extinction affected ecosystems and the patterns and processes involved in the subsequent biotic recovery. Vertebrate fossil assemblages of continental deposits in current-day South Africa, China, and Russia are the best source of information of this clade during the aftermath of the extinction event. Although considerably less sampled, the Induan continental rocks of the Panchet Formation of the Damodar Basin (eastern India) have also yielded a relatively diverse vertebrate assemblage composed of fishes, temnospondyls, synapsids, and a single proterosuchid taxon. Here, we report on a small isolated diapsid partial ilium (ISIR 1132) from the upper Panchet Formation. This specimen has a distinct morphology compared to other tetrapods that we know, including a shallow emargination on the dorsal margin of the anterior portion of the iliac blade, and ratio between height of iliac blade versus maximum height of iliac acetabulum at level of the dorsalmost extension of supraacetabular crest ≤0.45. Comparisons and a quantitative phylogenetic analysis found ISIR 1132 as a non-archosauromorph neodiapsid. This new specimen expands the reptile diversity in the Panchet Formation as well as for the rest of Gondwana, where Early Triassic non-archosauromorph neodiapsid species are extremely scarce.


LITOSFERA ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 625-643
Author(s):  
O. P. Tel’nova ◽  
I. Kh. Shumilov

Research subject. Terrigenous rocks of the Sargaevo stage of sedimentation in various structural-facies settings within the Tsilma area (Middle Timan). Material and methods. The composition, structural features of rocks, and the species diversity of spores of higher plants were studied in the most complete natural outcrops proposed as a stratotype of the Paladinskaya Formation – a new straton of the Sargaevo age in the Middle Timan. Over a large area of the region, the deposits contain very few remains of fossil fauna, often indifferent. As a result, palynostratigraphy was selected as the main biostratigraphic method. Results. In the Middle Timan, a new straton, the Paladinskaya Formation, is described, which characterizes the Sargaevo stage of sedimentation in various structural-facies settings within the Tsil’ma area. The new straton has clear lithological and detailed palynological characteristics; a description of the limitotypes was performed.At present, the Paladinskaya Formation is the most complete sequence of Early Frasnian sedimentation in the European North-East of Russia, where it was possible to record regional responses to the global Frasnes event and to determine the position of the controversial level of the boundary between the Middle and Upper Devonian. Conclusions. The name “Ust’e Yarega” Formation in the Middle Timan cannot be considered valid, since it is a homonym of the sediments of the same age in the South Timan. The section is represented mainly by continental, rather than marine, deposits. A new name for the identifed formation is proposed – “Paladinskaya” with a description of the stratum section and limitotype.The Paladinskaya Formation is characterized by subcomplexes of spores (А and Б) of the regional miospore zone Cristatisporites pseudodeliquescens, which made it possible to correlate the marine and continental deposits of the Early Frasnian on the territory of the entire Timan-Pechora region and establish its exact position in the stratigraphic scheme of the Devonian.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12360
Author(s):  
Caizhi Shen ◽  
Rodrigo V. Pêgas ◽  
Chunling Gao ◽  
Martin Kundrát ◽  
Lijun Zhang ◽  
...  

The Tapejarinae are edentulous pterosaurs that are relatively common in Cretaceous continental deposits in South America, North Africa, Europe, and China (mostly Early Cretaceous). The Chinese Jiufotang Formation is particularly rich in tapejarine specimens, having yielded over 10 described specimens and dozens of undescribed ones. For the Jiufotang Formation, a total of seven nominal tapejarid species and two genera have been proposed. Some debate exists over how many of those are valid or, alternatively, sexual or ontogenetic morphs of fewer (or even a single) species. Despite the abundance of specimens and the relevant taxonomic problems involved, detailed revisions of the matter are still lacking. This is partly due to the relatively scarce knowledge on the comparative osteology of the Sinopterus complex, which is hampered by the fact that most specimens have been only preliminarily described. In this contribution, we present a new postcranial specimen, D3072, which we attribute to the type-species of the genus, Sinopterus dongi. This new specimen helps shed some new light in the osteology of Sinopterus dongi, hopefully serving as a basis for future comparative studies involving further specimens and other proposed species and, subsequently, taxonomic revisions.


Author(s):  
Neha Aggarwal

AbstractPalynofacies is based on the different types of the dispersed/sedimentary organic matter (DOM/SOM) and has been used as a proficient proxy for the palaeoclimatic reconstructions in sedimentary deposits of various time spans. It has also been acknowledged as an effective tool in the different domains like sequence biostratigraphy, palyno-biostratigraphy, palaeodepositional history, identification for depositional processes, oxic–anoxic environment, and variations in the water depth. It has been emerged as an analytical tool in palaeoclimatic reconstruction, which could complement geophysical and geochemical datasets. Since long palynofacies analysis has been exclusively applied in the marine sediments, it has recently dragged the attention of many researchers as a significant parameter for palaeoclimatic interpretation in continental deposits. In the last few decades, more consideration was focused on palynofacies that have become an essential proxy in the biostratigraphic and other non-biostratigraphic fields due to its requirement in the petroleum industries. The present study provides a basic idea of dispersed organic matter characterization, methodology, interpretations, and its application with special emphasis on the Gondwana deposits. The study also includes the summary of the worldwide distribution of the Gondwana sediments, especially for palaeodepositional settings through palynofacies along with other parameters.


2021 ◽  
Author(s):  
Semen Mikhailovich Igitov ◽  
Ivan Nikolaevich Esipenok ◽  
Azat Mavlutovich Ishkinov ◽  
Anastasiia Sergeevna Vanina ◽  
Konstantin Gennadievich Olkhovsky ◽  
...  

Abstract The aim of the article is creation a conceptual model based on the data of chromatic technology data interpretation to improve the quality of forecasting potentially productive areas of occurrence of Jurassic formations of the Tyumen formation, as well as ranking the deposit by priority zones based on multifactor analysis. The article uses methods of complex reinterpretation of seismic and geological-geophysical materials in order to search for and localize highly productive zones of the Tyumen formation formations. The result of the work is a detailed strategy formed: the exploration and production drilling of the J2 formation. A significant increase in the expected ability of potentially productive objects in the inter-well space in the conditions of complex reservoirs due to modern processing technologies and interpretation was noted. The prospects of translating the methodology for optimizing the development of Jurassic objects of the Tyumen Fm at the fields of Slavneft-Megionneftegaz and other assets of Russian oil producing companies are revealed.


2021 ◽  
Vol 29 (4) ◽  
pp. 434-449
Author(s):  
N. V. Nosova ◽  
E. I. Kostina ◽  
E. V. Bugdaeva

Abstract The leaves of the genus Pseudotorellia from the Upper Jurassic–Lower Cretaceous of the Bureya Basin (Russian Far East) have been revised. The similarity of Pseudotorellia angustifolia Doludenko and P. longifolia Doludenko in the morphology and epidermal characters suggests that P. longifolia is a synonym of P. angustifolia. Leaves of this genus from the Bureya Basin previously assigned to P. ensiformis (Heer) Doludenko according to both morphological and epidermal characters are described as a new species P. doludenkoae sp. nov., since the type specimens of P.ensiformis from the Irkutsk Basin do not have preserved cuticles and their leaf epidermal characters are unknown. The epidermal characters of leaves described previously as Pseudotorellia pulchella and P. crassifolia have been studied for the first time. Since these species have similar morphological and epidermal characters, they are described as P. crassifolia, and its emended diagnosis is provided. The well-defined epidermal characters of Pseudotorellia allow us to reliably assign even cuticle fragments and dispersed cuticles to a particular species. This indicates a large stratigraphic potential of the Pseudotorellia species for the intrabasin and interregional stratigraphy of continental deposits, especially when studying the core material and coals, where the preservation of plant remains usually does not allow describing their morphology. The revision of all known occurrences of Pseudotorellia angustifolia makes it possible to discuss the place and time of the first appearance of this species and its subsequent distribution in space and time. Apparently, this species appeared in the Early Jurassic of Eastern Siberia (Kansk Basin). In the Middle Jurassic, its range expanded both to the northwest (Tomsk oblast and Yamal-Nenets Autonomous Okrug), where this species was preserved until the Late Jurassic, and to the east (Irkutsk oblast, Khabarovsk krai (Bureya Basin)), where it survived until the Early Cretaceous.


Geosciences ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 245
Author(s):  
Vania Mancinelli ◽  
Gian Paolo Cavinato ◽  
Francesco Ciavattella ◽  
Alessandro Cecili ◽  
Maurizio D’Orefice ◽  
...  

Quaternary continental deposits record spatio-temporal changes of the landscape and offer insights for drainage network analysis and paleoenvironmental reconstructions. This paper focuses on the Turano River, a left tributary of the Velino River, which flows in the southwestern Abruzzo area at the boundary with Lazio Region. Its basin preserves lithological and morphological field evidence particularly suitable for reconstructing the long-term geomorphological evolution of the Central Apennines and the drainage network development. In detail, the Turano River was investigated through a drainage basin-scale analysis incorporating morphometric analysis, field mapping, continental deposits analysis, and integrated drainage network analysis. This approach allowed us to define a drainage network reversal process, clearly highlighted by the spatial arrangement of continental deposits, spanning from Upper Pliocene to Holocene. The results also indicated tectonic activity as the main factor driving incision and river inversion processes. The work contributes to identifying and describing the main steps of the Quaternary landscape evolution of this mountainous catchment and its morphoneotectonic framework. Therefore, it could represent a methodological tool for multidisciplinary studies in similar mountainous catchments to support any territorial planning activity, from large infrastructure localization (i.e., artificial dams) to sustainable land management.


2021 ◽  
Author(s):  
Khaled Trabelsi ◽  
Benjamin Sames ◽  
Michael Wagreich ◽  
Miklós Kázmér ◽  
Andrea Mindszenty ◽  
...  

<p>The Eocene ‘‘blue hole” freshwater limestones from the bauxite cover-sequence at the Gánt karst system (Vértes Hills), Transdanubian Central Range, north-western Hungary, have yielded rich charophyte assemblages of higher taxonomic and biostratigraphic interest. The taxonomic study of this flora allows revision and emendation of the species Raskyella peckii and facilitates the definition of a new evolutionary anagenetic lineage based on three successive anagenetic varieties of this species which were formerly considered as separate species or subspecies: Raskyella peckii var. peckii (early Lutetian–early Bartonian), Raskyella peckii var. caliciformis (early Bartonian), and Raskyella peckii var. vadaszii (late Bartonian). Based on these, we propose a new local charophyte biozonation with the new Raskyella peckii Superzone (Lutetian–Bartonian), subdivided into three successive charophyte partial range zones: The ‘Raskyella peckii peckii Zone’ (Lutetian–lowermost Bartonian) is locally characterized by an assemblage of R. peckii peckii, Gyrogona caelata forma caelata, G. caelata forma monolifera and Nitellopsis (Tectochara) palaeohungarica. The ‘Raskyella peckii caliciformis Zone’ (lower Bartonian) includes the local assemblage of R. peckii var. caliciformis, G. caelata forma caelata, G. caelata forma monolifera, G. caelata forma baccata, Nitellopsis (Tectochara) palaeohungarica and Chara media. The ‘Raskyella peckii vadaszii Zone’ (upper Bartonian) is composed of the local assemblage of R. peckii var. vadaszii, G. caelata forma bicincta, G. caelata forma baccata, G. caelata forma fasciata, G. tuberosa, Psilochara polita, Psilochara sp., Chara media and Chara subcylindrica. Future research may show the new local biozonation as applicable to whole Europe and complementing the current European charophyte biozonation. Our results show that the sequences from Gánt previously regarded as upper mid-Eocene (upper Lutetian–lower Bartonian) appear to comprise a longer chronostratigraphic interval, i.e. lower Lutetian till upper Bartonian, with also has implications on the understanding of the regional stratigraphy of the Transdanubian Central Range during the Eocene.</p>


2021 ◽  
Vol 240 ◽  
pp. 04001
Author(s):  
Abdelouhed Farah ◽  
Ahmed Algouti ◽  
Abdellah Algouti ◽  
Fatiha Hadach ◽  
zahra Mourabit

The study area belongs to the southern edge of the central High Atlas. It is limited to the North by the Sub-atlasic accident and to the South by the extension of the Eastern Anti Atlas formations. To determine the depositional environments of the Senonian series, a sedimentological analysis of the facies was carried out based on field observations by the recognition of sedimentary structures and textures. An exoscopic analysis of the quartz grains was also carried out by a systematic prospecting of the grain relief and of all the characters that will appear on the surface of the grain after the formation of the mother rock at the origin place, during transport, immobilization phases and deposition. It seems very interesting to prospect for the clayey side in these Upper Cretaceous reddish formations because the evolution of the clayey and non-clayey assemblages in this central basin of the High Atlas will depend mainly on the combination of tectonic, eustatic, climatic and other influences. The Senonian of Foum El Kous which has a less important thickness corresponds to continental deposits that act the role of a natural barrier that separates on both sides the two sub-basins: Sidi Ali Oubork in the East and Ait youl in the West.


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