scholarly journals BIOSTRATIGRAPHY AND CORRELATION OF DEVONIAN DEPOSITS IN THE SOUTH-WEST SEGMENT OF THE EAST-EUROPEAN PLATFORM BY BRACHIOPODS

2021 ◽  
pp. 74-84
Author(s):  
O.Yu. Kotlyar

The main aim of the paper is to study the detailed distribution of the brachiopod fauna throughout the entire Devonian section from the Silurian-Devonian boundary at the Podilla region to the Devonian-Carboniferous boundary at the SW slope of the Dnipro-Donets Depression (DDD). The Devonian brachiopods (mainly Productids, Spiriferids and Rhynchonellids) of the south-west segment of the East-European Platform (EEP) are reviewed from the DDD, Volhyn-Podilla monocline (VPM) including the L’viv Paleozoic Trough, and Fore-Dobrogea Paleozoic Depression (FDPD). The faunas of these regions are mutually related and compared to the Devonian faunas of the EEP (Russia) and Pripyat’ Depression (Belarus). In recent years several paleontological investigations have broadened and deepened our knowledge of the Devonian biostratigraphy of Ukraine. Based on systematic studies of brachiopods from the SW segment of the EEP we recognize four successive faunas corresponding to four great marine transgressions — Early Devonian (Tiwer Series, the Monograptus uniformis Zone), Middle Devonian (Givetian Stage, the conodont varcus Zone), Late Frasnian (the conodont Upper rhenana — linguiformis Zone), and Early Famennian (the conodont triangularis-crepida Zone). The Early Devonian association includes Howellella angustiplicata, Plectodonta maria, and Daiya navicula and others which are similar to late Silurian brachiopods by their generic features (represented the genus common with the Upper Silurian). The Middle Devonian assemblages contain: Emanuella volhynica, Atrypa (Desquamatia) ventricosa, Chonetes sarcinulata, and Poloniproductus productoides at VPM sections (Givetian Stage, the varcus Zone), as well as Variatrypa sokolovae (Eifelian Stage), but in the DDD sections the impoverished association with Stringocephalus cf. burtini (Eifelian Stage) and Atrypa uralica (Givetian Stage) occur. The Late Frasnian association is represented by dominance of Theodossia tanaica, T. evlanensis, T. livnensis at all regions — VPM, DDD and FDPD (the Upper rhenana — linguiformis zones). The Early Famennian association is represented by ex Cyrtospirifer archiaci = Cyrtospirifer asiaticus and Cyrtospirifer ljachovichensis, Cyrtiopsis sp., Ptychomaletoechia zadonica, Iloerhynchus tichomirovi, Ardiviscus ex gr.herminae, Steinhagella annae etc. at DDD and by the same association plus Dmitria angustirostris at VPM (the triangularis-crepida zones). Brachiopods near the D-C boundary have been recorded so far from the black shales fossiliferous deeper water facies only in DDD: Spinocarinifera nigra, S. fallax, Sphenospira julii, Parallelora sp. (the Siphonodella praesulcata Zone). The result of our systematic study of productids, spiriferids, rhynchonellids, atrypids, and athyrids from Ukrainian sections are in perfect agreement with, and supplement to the previous investigations of Middle and Upper Devonian deposits at VPM and DDD, suggesting their important role for precising boundaries between the Devonian stages and horizons in SW segment of EEP. The essential role of brachiopods for the Devonian biostratigraphy and correlations with the East-European biozonation is confirmed.

Author(s):  
Wolfgang Dörr ◽  
Eckhardt Stein ◽  
Ferdinand Kirchner ◽  
Henri Paul Meinaß ◽  
Felicitás Velledits

AbstractU–Pb age spectra of detrital zircons related to the East European Platform could be traced in paragneiss through the whole Mid-German-Crystalline Zone (Variscides, Central Europe) from the Odenwald via the Spessart to the Ruhla crystalline forming an exotic unit between Armorica and Laurussia. The depositional ages of the paragneiss are defined by the youngest age of the detrital zircons and the oldest intrusion ages as Ordovician to Silurian. The Ediacaran dominated age spectrum of detrital zircons from the paragneiss of the East Odenwald suggests the latter to be derived from the shelf of the East European Platform (Baltica), which was influenced by the 1.5 Ga old detritus delivered from a giant intrusion (Mazury granitoid, Poland). The detrital zircon age spectrum of the lower Palaeozoic paragneiss of the East Odenwald and sandstone of the northern Holy Cross Mountains are identical. The pure Sveconorwegian spectrum of the lower Palaeozoic quartzite from the Spessart, (Kirchner and Albert Int J Earth Sci 2020) and the Ruhla (Zeh and Gerdes Gondwana Res 17:254–263, 2010) could be sourced from Bornholm and southern Sweden. A U–Pb age spectrum with 88% Palaeozoic detrital zircons from a volcano-sedimentary rock of the East Odenwald is interpreted to be derived from a Silurian magmatic arc (46%), which was probably generated during the drift of the Mid-German-Crystalline Zone micro-continent to the south. A tentative plate tectonic model of Mid-German-Crystalline Zone is presented taking into account (a) the East European Platform related age spectra of the detrital zircons (b) the Ordovician to Silurian depositional age of the metasediments (c) the Silurian and Early Devonian intrusion age of the plutonic and volcanic rocks and (d) the U–Pb ages of the Middle Devonian high-grade metamorphism. The East European Platform-related part of the Mid-German-Crystalline Zone is interpreted as a micro-continent, which drifted through the Rheic Ocean to the south and collided with the Saxothuringian (Armorican Terrane Assemblage) during the Early Devonian. Such large-scale tectonic transport from the northern continent to the southern continent is also known from the SW Iberia, where Laurussia-related metasediments of the Rheic suture zone are explained by a large scale tectonic escape (Braid et al. J Geol Soc Lond 168:383–392, 2011).


2020 ◽  
pp. 72-81
Author(s):  
G.G. Kamkin ◽  

The article is devoted to the analysis of urban “highways-barriers” (on the example of the South-West of Moscow) – the largest highways and railways, which are characterized by a combination of a high level of contact and barrier functions. Three of their key functions are identified: limiting, stabilizing, function of unevenness and no equilibrium growth. The main transport hubs have been identified on the basis of which highway barriers are divided according to the degree of contact (barrier) into three categories. It is shown that, as a rule, the larger the spatial size of the highway-barrier, the larger its volume of traffic flow, however, there are many exceptions. In the South-West of Moscow, with a relatively even settlement, the placement of metro stations plays a key role in overcoming the barrier. On less significant highways, the role of metro stations in overcoming the barrier is especially great. In some areas, highways-barriers form barrier topological tiers. A key feature of the South-West of Moscow is the presence of two barrier tiers. Inside the first barrier tier there are objects that mark it as a special urban area. A characteristic part of the first tier is the approach to the periphery in the area where Leninsky Prospekt and Vernadsky Prospekt meet. The second barrier tier is quite small and in- cludes the area between the Cheremushkinskiy market and Profsoyuznaya street. The existing system of highways-barriers was formed by the time of registration in 1968–1970. South-West of Moscow as a whole and manifests itself at the present time.


2019 ◽  
Vol 27 (4) ◽  
pp. 442-474 ◽  
Author(s):  
A. S. Zastrozhnov ◽  
S. V. Popov ◽  
V. N. Beniamovsky ◽  
V. A. Musatov ◽  
M. A. Akhmetiev ◽  
...  

1966 ◽  
Vol 4 (3) ◽  
pp. 375-380
Author(s):  
Sol Picciotto

The judgment of the International Court of Justice of 18 July 1966 in the South-West Africa case throws revealing light on the role of that Court in the international community. A proper analysis of this case may also help to dispel some of the mystification about international law and the attitude of the new nations to it.


1991 ◽  
Vol 31 (6) ◽  
pp. 803 ◽  
Author(s):  
PJ Dolling ◽  
WM Porter ◽  
AD Robson

The effect of soil acidity on barley growth in Western Australia and the role of aluminium toxicity and nutrient deficiencies were examined at 9 sites using 5 application rates of lime and 3 levels of supply of nutrients. Nutrient plant analysis was also used to assess the mechanisms involved in any response to lime.Lime application increased barley yields at 3 sites, by 9-30%, by alleviating aluminium toxicity. Nutrient treatments did not interact with the lime response. The largest reduction in grain yield (>15%) that was due to aluminium toxicity occurred at the site which had the lowest pH (4.3 in 0.01 mol CaCl2/L) and the highest concentration of CaCl2-extractable aluminium (5 �g/g).


2020 ◽  
Vol 21 (2) ◽  
pp. 129-139 ◽  
Author(s):  
Ailsa Cameron ◽  
Eleanor K. Johnson ◽  
Paul B. Willis ◽  
Liz Lloyd ◽  
Randall Smith

Purpose This paper aims to report the findings of a study that explores the contribution volunteers make to social care for older adults, identifying lessons for the social care sector and policymakers. Design/methodology/approach An exploratory multiple case study design was used to capture the perspectives and experiences of managers of services, volunteer co-ordinators, volunteers, paid care staff and older people. Seven diverse social care organisations took part in the study drawn from three locations in the South West of England. Findings This study identified three distinct models of volunteer contribution to social care services for older people. Although the contributions made by volunteers to services are valued, the study drew attention to some of the challenges related to their involvement. Research limitations/implications The organisations taking part in this small-scale study were all based in the South West of England, and the findings are therefore not generalisable but contribute to the growing evidence base related to this important field. Practical implications This study demonstrates the importance of the volunteer co-ordinator role and suggests that it is properly funded and resourced. It also confirms the importance of volunteers receiving appropriate training and support. Originality/value Given the increasing involvement of volunteers in the provision of social care, this paper provides lessons to ensure the role of volunteers in social care enhances rather than diminishes the quality of care provided.


2003 ◽  
Vol 50 ◽  
pp. 75-94
Author(s):  
Svend Stouge ◽  
Arne Thorshøj Nielsen

The Komstad Limestone is composed of dark grey to black micritic limestone deposited in an outer shelf environment on the margin of the East European Platform. It represents an interval of low sea level during the late Volkhov to early Kunda that led to the spread of limestones into the shale-dominated western lithofacies belt. The Baltoniodus norrlandicus, Lenodus antivariabilis, Lenodus variabilis, Yangtzeplacognathus crassus and Lenodus pseudoplanus conodont zones were identified in the upper Volkhov to lower Kunda interval. Based on the most recent taxonomic and biostratigraphical framework, the Megistaspis limbata (with two subzones), Asaphus expansus and Asaphus raniceps trilobite zones were identified. A shale intercalation in the lower part of the Komstad Limestone contains the graptolites Phyllograptus cor in association with Glyptograptus sp. and is referred to Darriwilian 1 (Upper Arenig). In the Baltoscandian zonation this matches the upper part of the Didymograptus hirundo graptolite Zone. The upper level of the Komstad Limestone and the basal part of the overlying Almelund Shale do not contain graptolites, whereas the succeeding black shales of the Almelund Shale belong to the Holmograptus lentus Zone (Llanvirn). The Arenig-Llanvirn boundary is situated at or very near the top of the Komstad Limestone. The conodont assemblage in the lower part of the Komstad Limestone at Fågelsång is associated with forms of Gondwanan affinity, which probably reflects the cool water environment of the outer shelf setting. The higher part of the limestone contains the Whiterockian conodont species Dzikodus sp. and Histiodella tableheadensis. These important Laurentian forms occur together with abundant Gothodus sp. 1 and Cyclopyge umbonata in the base of the Asaphus expansus Zone. The arrival of the Laurentian taxa – as well as Cyclopyge with an ‘Gondwana’ affinity – is related to a transient sea level rise at the base of the A. expansus trilobite Zone.


LITOSFERA ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 560-573
Author(s):  
A. G. Mizens ◽  
L. I. Mizens

Research subject. Brachiopods from the core of the Kurgan-Uspenskaya-1 parametric borehole. The borehole was drilled in the south of Western Siberia 80 km southeast of the Kurgan town. Brachiopods were collected at a depth of 1,525.4 m in the IV tectonic block (core interval 1,450–1,794 m) in the greenish-gray marls of the Famennian stage of the Upper Devonian.Materials and methods. The paleontological material is presented in the form of complete undamaged shells and individual valves of small- and medium-sized brachiopods. The safety of brachiopods makes it possible to determine their species and genera, sometimes in open nomenclature. The article provides a brief description of the available material.Results. 11 species of brachiopods of the subtype Rhynchonelliformea belonging to six orders and nine genera were identified. The following ten species were described: Orbinaria fallax (Pand.), Semiproductus amplus Bubl., Schuchertella sp., Dalejina? sp., Camarotoechia panderi (Sem.et Moell.), C. volucera Nal., Athyris tobolica Nal., Cleiothyridina tenuilineata (Row.), Cl. ex gr. pectinata (Sem. et Moell.), Retzia? sp. The presented information allows conclusions about the age of the sediments enclosing the brachiopods under study and expands the existing knowledge of both the composition of the Upper Famennian brachiopods of the basement of the south of Western Siberia and their geographical and stratigraphic distribution.Conclusion. An analysis of the stratigraphic distribution of the described brachiopods taking into account data on foraminifera allowed us to determine the age of the host rocks as the very top of the Famennian stage. The composition of the brachiopods allows these rocks to be correlated with coeval deposits of the East European Platform, Timan, the Urals, Kuzbass, the Gorny Altai, Kazakhstan and North America.


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