scholarly journals The ammonite zones of the Bathonian in Bulgaria

2017 ◽  
Vol 46 (2) ◽  
pp. 57-63
Author(s):  
Lubomir Metodiev ◽  
Ivo Sapunov
Keyword(s):  
Limited Extent ◽  
Considerable Part ◽  
Zonal Scale ◽  
Nw Europe ◽  
Ammonite Zones

A scheme of nine ammonite zones for the Bathonian in Bulgaria is described herein. The stratigraphical distribution of the Bathonian ammonites has been revised through new collecting and re-examination of older collections and fields. It has become evident that the criteria for zonal discrimination applied in NW Europe are relevant for Bulgaria to a limited extent, and we cannot compare directly our successions with those from the NW European areas as done in earlier work. Also, many traits of typically Submediterranean dispersal have been found to take a considerable part of the ammonite associations. Therefore, a composite Submediterranean–NW European zonation seems to be applicable to the Bathonian ammonite successions in Bulgaria. The ammonite zonal scale used in previous Bulgarian accounts has been retained, but several changes have been made to attain a more balanced sequence. This scale can be subject to further confirmation and modification, as not enough biostratigraphically well-constrained specimens have yet become available to characterize the ranges and variability of the zones.

The ammonite fauna renewal at the boundary middle–late Toarcian: new data and consequences

2005 ◽  
Vol 176 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Marc Becaud ◽  
Louis Rulleau ◽  
Serge Elmi
Keyword(s):  
Long Range ◽  
New Taxa ◽  
Middle Jurassic ◽  
The West ◽  
Lower Upper ◽  
Western Tethys ◽  
Reference Sections ◽  
Limit Result ◽  
Nw Europe ◽  
Ammonite Zones

Abstract Several proposals have been made concerning the Toarcian informal substages. A three part division, here adopted, includes a Middle Toarcian encompassing the Bifrons and Variabilis ammonite zones, according to the definition well established by Monestier [1921]. Other authors, following Buckman [1888], admit a binary definition but with different meanings. The boundary is placed either below the Variabilis (Lower / Upper Toarcian limit), or below the Thouarsense zones (“Whitbian”–“Yeovilian” limit) [Howarth, 1992]. These differences are largely due to a strong sedimentary instability: condensations, gaps and faunal mixings were widespread during the Variabilis zone in NW Europe and eurocaucasian domain and its Tethyan equivalent, the Gradata zone. Contemporarily, a major renewal occurred in the ammonite faunas. This provoked a near general segregation that is the reason of the use of different zone standards. In NW Europe, the faunal renewal occurred during the Variabilis zone as it as been established in the stratotype localities of Poitou and Vendée (Poitou – Vendée) [Gabilly, 1973, 1976a]. This is also well known in the Causses [Guex, 1972, 1975]. These two areas give good reference sections for the ammonite succession at the top of the Middle Toarcian. These data have been supplemented by recent works concerning NW Europe as well as the Tethyan margins (Portugal, Betics, Morocco, Algeria, Apennines). New observations have also been realized in France (Poitou-Vendée, Causses, Lyon area). They allow to have a better knowledge of the development of the faunal renewal and of the appearance of new taxa (genus, sub and superfamilies). Special attention is given to the Phymatoceratids, Grammoceratids and Hammatoceratoids. In consequence, the main renewal did not happened at the end of the Middle Toarcian (end of the Variabilis zone) but sooner at the beginning of the Illustris subzone. New ammonite morphologies appeared that will dominate the assemblages at the beginning of the late Toarcian (Grammoceratinids) and that will be at the origin of the main Middle Jurassic assemblages (Hammatoceratids). Among the species from the Illustris subzone, some are good markers for the correlations between the faunal domains and provinces (“Pseudogrammoceras” aratum Buck., “Pseudogrammoceras” subregale Pinna, “Geczyceras” costatum (Gab.), Osperleioceras (Pseudopolyplectus) bicarinatum (Ziet.)). It appears that the difficulties to place the Middle–Upper Toarcian limit result closely of the sedimentary perturbations that happened in Europe from the west to the eurocaucasian domains and in the whole western Tethys. The substage problem is secondary as stated by Gabilly but it is convenient for long range comparisons. The main units to establish the correlations are the biostratigraphic zones (biozones). In such a matter, the Variabilis zone is of particular importance, according to the coeval sedimentary and palaeontologic events.

Cenomanian and lower Turonian relative chronology and palaeoenvironmental framework of the Nouader site (Aures Basin, Northeastern Algeria)

2019 ◽  
Vol 156 (11) ◽  
pp. 1877-1891 ◽  
Author(s):  
Aida Bensekhria ◽  
Ramdane Marmi ◽  
Abdelouahab Yahiaoui
Keyword(s):  
Planktonic Foraminifera ◽  
Lower Upper ◽  
Central Tunisia ◽  
Relative Chronology ◽  
Taxonomic Groups ◽  
Depositional Setting ◽  
First Time ◽  
Nw Europe ◽  
Northeastern Algeria ◽  
Ammonite Zones

AbstractThe lower–upper Cenomanian boundaries interval of the Nouader site in the Aures Basin (NE Algeria) has been studied for the first time using the association of two particularly effective taxonomic groups, one macrofossil (ammonites), and the other microfossil (foraminifera). The study section is divided into two formations (Fahdene and Bahloul) and one member (Annaba). Biostratigraphicaly, six ammonite biozones and five foraminiferan biozones were identified and calibrated. The ammonite fauna allows recognition of the lower CenomanianMantelliceras mantelliZone, the upper lower CenomanianMantelliceras dixoniZone, the succeeding lower middle CenomanianCunningtoniceras inermeZone, theAcanthoceras rhotomagenseZone and its subzones ofTurrilites costatusandTurrilites acutus, followed by the upper middle CenomanianAcanthoceras amphibolumZone, the lower upper CenomanianEucalycoceras pentagonumZone and finally the lower TuronianPseudaspidoceras flexuosumZone. The foraminiferan biozones are respectively:Thalmanninella brotzeniZone,Thalmanninella reicheliZone,Rotalipora cushmaniZone,Whiteinella archaeocretaceaZone andHelvetoglobotruncana helveticaZone. Among 14 ammonite zones in the Tethyan domain versus 11 in the Boreal domain, seven are common to both domains. For the planktonic foraminifera the Tethyan domain has five zones, the Boreal domain also has five, with five in common. The succession of index species occurs in the same order in both Tethyan (NE Algeria and Central Tunisia) and Boreal realms (East and NW Europe). Furthermore, the supposed depositional setting is interpreted as a calm and relatively deep environment which can be located around the middle to the external platform.

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

The Necessity and Ways of Legitimation of Large-scale Private Property in Russia: Raising a Problem

2007 ◽  
pp. 4-26
Author(s):  
G. Yavlinsky
Keyword(s):  
Large Scale ◽  
Private Property ◽  
Negative Consequences ◽  
Specific Nature ◽  
Considerable Part ◽  
Russian People ◽  
National Importance ◽  
Historical Tradition ◽  
Special Rules ◽  
Economic Assets

Results of privatization campaign in 1990’s continue to meet strong opposition from a very considerable part of Russian people and authorities actually refuse to consider the rights of private owners legitimate and not subject to violation. One of the reasons for this, besides historical tradition, is a specific nature of Russian privatization of 1990’s. The article brings to discussion a set of measures aimed at overcoming its negative consequences. While insisting on the need to honor all previous government obligations and commitments, the paper proposes a one-time special tax (windfall tax) to be levied on those who benefited most from privatization deals that were not just and fair, and special rules to be set for the use and sale of economic assets of national importance. The author also considers possible ways to legitimize private property, as well as chances to achieve а broad public consensus on this issue in Russia.

CHROMATOGRAPHIC STUDIES ON 131I-COMPOUNDS IN FAECES AND BILE

1964 ◽  
Vol 47 (2) ◽  
pp. 343-352
Author(s):  
B. Blomstedt ◽  
H. Y. Neujahr
Keyword(s):  
Intravenous Administration ◽  
Glucuronic Acid ◽  
Free Triiodothyronine ◽  
Considerable Part ◽  
Human Faeces ◽  
Total Excretion

ABSTRACT The occurrence of 131I-compounds in human faeces was studied after intravenous administration of 131I-thyroxine. The excretion of the radioactivity during 12 days ranged from 7.8 to 32.1 per cent of the dose administered with a mean of 16.0 (± 1.76). The radioactivity in the faeces was derived from free 131I-thyroxine. The total amount of faeces did not seem to influence the total excretion of the dose administered. After administration of 131I-triiodothyronine to rats and humans, triiodothyronine occurred in the bile mainly conjugated with glucuronic acid, but a considerable part of the radioactivity was found in diiodotyrosine. The radioacivity of human faeces after the administration of 131I-triiodothyronine was derived from free triiodothyronine. After injection of 131I-diiodotyrosine only labelled iodide was detected in the bile of rats. In the bile of humans most of the radioactivity was derived from iodide, and a small part of it was found in diiodotyrosine.

Role of chromium (III) in the nutrition of pigs and cattle

2016 ◽  
Vol 3 (2) ◽  
pp. 56-62
Author(s):  
R. Iskra ◽  
V. Vlizlo ◽  
R. Fedoruk
Keyword(s):  
Growth And Development ◽  
Reproductive Function ◽  
Metabolic Effect ◽  
Considerable Part ◽  
Cultural Medium ◽  
Milk Performance ◽  
Chromium Compounds ◽  
The Impact ◽  
Different Sources

The results of our studies and the data of modern literature regarding the biological role of Cr(III) compounds in conditions of their application in the nutrition for pigs and cattle are discussed. The metabolic impact of Cr(III), coming from different sources – mineral and organic compounds, obtained by chemical synthesis or a nanotechnological method (chromium citrate), as well as in the form of biocomplexes from the cultural medium of Saccharomyces cerevisiae yeasts was analyzed. The metabolic connection between the impact of Cr(III) and the biosynthesis of some hormones – insulin, cortisol – as well as the sensitivity of some tissues and organs to the effect of chromium compounds was studied. A considerable part of the review material was dedicated to the metabolic effect of Cr(III) compounds on the reproductive function of pigs and cattle and their impact on the viability of the offspring and gametes of animals. The data about the stimulating effect of Cr(III) on the growth and development of the organism of piglets and calves, meat and milk performance of these species of animals are discussed. The relevance of dosing Cr(III) in the nutrition of pigs and cattle is highlighted.

Notes on the correlation of Russian and Midcontinent Carboniferous and Permian ammonite zones

1937 ◽  
Vol s5-33 (198) ◽  
pp. 462-472
Author(s):  
F. B. Plummer ◽  
C. O. Dunbar ◽  
M. K. Miller
Keyword(s):  
Ammonite Zones

RESEARCH COLLABORATION AMONG LIBRARY AND INFORMATION SCIENCE SCHOOLS IN SOUTH AFRICA (1991–2012): AN INFORMETRICS STUDY

Mousaion ◽  
2017 ◽  
Vol 34 (3) ◽  
pp. 36-59 ◽  
Author(s):  
Jan R. Maluleka ◽  
Omwoyo B. Onyancha
Keyword(s):  
South Africa ◽  
Information Science ◽  
Research Collaboration ◽  
Science And Technology ◽  
Library And Information Science ◽  
Limited Extent ◽  
Microsoft Excel ◽  
The Past ◽  
Software Packages ◽  
Collaborative Activities

This study sought to assess the extent of research collaboration in Library and Information Science (LIS) schools in South Africa between 1991 and 2012. Informetric research techniques were used to obtain relevant data for the study. The data was extracted from two EBSCO-hosted databases, namely, Library and Information Science Source (LISS) and Library, Information Science and Technology Abstracts (LISTA). The search was limited to scholarly peer reviewed articles published between 1991 and 2012. The data was analysed using Microsoft Excel ©2010 and UCINET for Windows ©2002 software packages. The findings revealed that research collaboration in LIS schools in South Africa has increased over the past two decades and mainly occurred between colleagues from the same department and institution; there were also collaborative activities at other levels, such as inter-institutional and inter-country, although to a limited extent; differences were noticeable when ranking authors according to different computations of their collaborative contributions; and educator-practitioner collaboration was rare. Several conclusions and recommendations based on the findings are offered in the article.

Reform oder Papstwahl: das Konzil in der Zerreißprobe. Eine innerkonziliare Auseinandersetzung zwischen ‘Mehrheit’ und ‘Minderheit’ auf dem Konstanzer Konzil

2020 ◽  
Vol 49 (2) ◽  
pp. 281-308
Author(s):  
Ansgar Frenken
Keyword(s):  
Limited Extent ◽  
Long Time ◽  
Key Events ◽  
The Church ◽  
Broad Consensus ◽  
National Borders

Abstract Reform or Papal Election – the Council and its Ordeal: An Inner-Conciliar Dispute between ‘Majority’ and ‘Minority’ at the Council of Constance. The broad consensus that prevailed among the Fathers at the beginning of the Council of Constance gave way to a climate of tension, at the latest after the resurgence of the English-French conflict in mid-1415, which made the inner tensions among the participants of the Council more and more apparent. The front that arose between ‘majority’ and ‘minority’ only followed ‘national’ borders to a limited extent, and for a long time it had not been firmly established, hence shifts and overlaps were still possible. The arrival of the Spaniards – first the Aragonese, later the Castilians – and the outbreak of the conflict of nations can be interpreted as key events in this development, which led to the formation of the two blocs. The national tensions between the English and the French were overlaid by the question of how the Council should proceed further: to proceed to the election of a new Pope first or to prioritize the reform of the church. For a long time both sides were in balance, but after the Castilians’ accession to the Council in the summer of 1417, the situation changed rapidly. The predominance of a coalition of Cardinals, Italica, Gallicana and the Castilians grew, while the group assembled around Sigmund, Germanica, Anglicana and the Aragonese increasingly eroded and became a ‘minority’. A finally negotiated compromise, in which both sides were able to save face, rendered a successful conclusion of the council possible.

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