Neoproterozoic Deposits of the Bashkir Mega-Anticlinorium (Southern Urals): State of the Art in Regional Stratigraphy

2021 ◽  
Vol 62 (11) ◽  
pp. 1240-1255
Author(s):  
S.A. Dub
Keyword(s):  
State Of The Art ◽  
Southern Urals ◽  
Alternative Variant ◽  
Upper Riphean ◽  
Stratigraphic Subdivision ◽  
Lithostratigraphic Units ◽  
Stratigraphic Position ◽  
The Uk ◽  
Contradictory Data ◽  
High Uncertainty

Abstract —This paper presents an alternative variant of stratigraphic subdivision of the upper Riphean–Vendian deposits (approximately corresponding to the Neoproterozoic Erathem of the International Chronostratigraphic Chart (ICC)) of the Bashkir Mega-Anticlinorium (BMA), based on the modern concepts of changes in the biosphere, atmosphere, and hydrosphere (and, accordingly, in the climate and the course of sedimentary processes) in the period ~1000–540 Ma, with regard to the results of recent studies and the proposals for improving the Russian General Stratigraphic Scale (GSS) of the Precambrian. The strict necessity of subdividing chronostratigraphic and lithostratigraphic units is shown. The presented data give grounds to regard the Zil’merdak Formation as a Group and assign three of its lower formations to the Middle Riphean (Yurmatinian). It is shown that the period of accumulation of the Karatau Group (comprising the Katav, Inzer, Min’yar, and Uk formations) was significantly shorter than the duration of the Late Riphean (Karatavian). Special attention is focused on the age of the Uk Formation (analysis of the existing data made it possible to refine its stratigraphic position): It formed, most likely, in the period 780–740 Ma. A high uncertainty of the stratigraphic position of the overlying geologic bodies is demonstrated. The Bakeevo, Tolparovo, Suirovo, and Kurgashla formations must be regarded as part of the Terminal Riphean (Arshinian). The Arsha Group, comprising the Bainas, Makhmutovo, Igonino, and Shum formations in the Tirlyan trough and represented by the Krivaya Luka Formation in the Krivaya Luka syncline, should not be totally assigned to the Terminal Riphean. It is proposed to exclude the Bakeevo Formation and the Tolparovo–Suirovo sequence from the Asha Group, because these deposits are, most likely, a modification of the Arsha Group located on the western flank of the BMA. The Uryuk Formation is probably of pre-Vendian age. The current contradictory data on the stratigraphy of the supra-Uryuk unit of the Asha Group are interpreted. The ages of the geologic bodies composing the Group and its stratigraphic interval still call for a thorough study.

scholarly journals Trace element behaviour in acidic leachates (acetic, nitric and hydrochloric) from siliciclastic-carbonate rocks of the Upper Riphean Uk formation in the Southern Urals

LITOSFERA ◽  
2020 ◽  
Vol 19 (6) ◽  
pp. 919-944
Author(s):  
S. A. Dub ◽  
N. V. Cherednichenko ◽  
D. V. Kiseleva ◽  
N. P. Gorbunova ◽  
T. Ya. Gulyaeva ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Rare Earth ◽  
Main Tool ◽  
Southern Urals ◽  
The Southern Urals ◽  
X Ray ◽  
Upper Riphean ◽  
Siliciclastic Rock ◽  
The Uk ◽  
Ree Pattern

Research subject. 14 samples of limestone and one sample of carbonate-siliciclastic rock from siliciclastic-carbonate deposits of the Upper Riphean Uk Formation (the Southern Urals) were studied.Methods. Mineral and chemical composition of the samples were determined; the main tool for detecting the concentrations of trace elements was the ICPMS method. X-ray diffraction analysis was carried out using a Shimadzu XRD-7000 diffractometer, the content of major (rock-forming) oxides in bulk samples was established by X-ray fluorescence spectrometry on the SRM-35 and Shimadzu XRF 1800 spectrometers. Microelement composition of bulk samples and acidic leachates obtained with using acetic (10%), nitric (36%) and hydrochloric (17%) acids was determined on a Perkin Elmer ELAN 9000 spectrometer.Results. The distribution of lithophile, rare-earth and a number of other elements (Sr, Ni, U) both in bulk samples and in acidic leachates was analyzed. The main carrier phases of these elements were revealed.Conclusions. 1. The use of any listed acids leads to the non-carbonate component entering the solution, including contamination of the “carbonate” leachates by lithophile elements. In particular, a transition Rb, Zr, Li, Th, Ti, Sc to leachates was noted. This process is most active in nitric and hydrochloric acids, less intensive in acetic acid. 2. Among the carriers of rare earth elements (REE) in the studied rocks are clays (1), accessory minerals (2), including phosphate-bearing grains, secondary carbonate phases represented by dolomite and, possibly (3), finely disseminated iron and manganese (oxy)hydroxides (4). It is assumed that the REE pattern in limestones is determined by the content of the epigenetic dolomite. The contribution of lanthanides bound in the sedimentary calcite crystal lattice in the total REE pattern is rather large only in relatively “pure” limestones. However, the use of acids with such concentrations did not allow to obtain a leachate, which the REE pattern with high probability corresponds to the distribution of REE in the Uk time seawater. But acetic acid is more effective for achieving this goal than the others. 3. In addition to Sr, sedimentary calcite also contains Ni and U.

scholarly journals Sedimentology and geochemistry of the Uk Formation, Upper Riphean, the Southern Urals

LITOSFERA ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 659-686 ◽  
Author(s):  
A. V. Maslov ◽  
D. V. Grazhdankin ◽  
S. A. Dub ◽  
D. S. Melnik ◽  
T. M. Parfenova ◽  
...  
Keyword(s):  
Organic Matter ◽  
Acetic Acid ◽  
Southern Urals ◽  
Depositional Environments ◽  
Gas Liquid Chromatography ◽  
The Southern Urals ◽  
Thin Sections ◽  
Fine Grained ◽  
Upper Riphean ◽  
The Uk

Research subject. This article presents new data on carbonate facies of the upperUk subformation, Upper Riphean of theSouth Urals. A particular attention is paid to the distribution of rare-earth elements (REE) and yttrium (Y) in stromatolitic and intraclastic limestones and calcareous shales (bulk samples and their acetic acid leachates).Materials and methods. We have studied lithological features of limestones in the geological section and in thin sections. The contents of trace elements in rocks were determined by the ICP-MS method at the IGG UB RAS (Yekaterinburg), the composition of organic matter was determined at the IPGG SB RAS (Novosibirsk) by gas-liquid chromatography and chromatography-mass spectrometry.Results. The most representative section of the Upper Uk Subformation located along the eastern edge of the town Ust-Katav can be subdivided into several members of different lithology and thickness: (1) biohermdominated member comprising large microbialitic build-ups and inter-bioherm sediments (intraclastic limestones, calcareous biolaminites); (2) transitional member characterised by small bioherms alternating with other carbonates; (3) interbedded coarseand fine-grained limestones. The presence of molar-tooth structures in the carbonate rocks of Uk Formation made it possible to constrain the age of thisUpper Riphean formation to pre-CryogenianConclusions. There are similarities in REE and Y distribution in both clean (devoid of siliciclastic component) bulk limestone samples and in their acetic acid leachates. PAAS-normalised REE + Y patterns demonstrate positive La, Gd, Y anomalies and negative Eu, Ce anomalies. The latter suggest marine depositional environments for theUpper Uk stromatolitic limestones. The results of the pioneering research into the composition of bitumens and biomarkers from the Upper Uk Subformation have shown that carbonates and shales are depleted in the organic matter. The source material for the organic matter was provided by two types of communities comprising both eukaryotes and prokaryotes and inhabiting well aerated environment, perhaps with lowered salinity of marine water. 

scholarly journals Limestones of the Uk Formation (Upper Riphean, the Southern Urals): Effect of contamination and diagenetic fluids on the distribution of rare-earth elements and yttrium

LITOSFERA ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 23-31
Author(s):  
A. V. Maslov
Keyword(s):  
Trace Elements ◽  
Carbonate Rocks ◽  
Southern Urals ◽  
Strong Positive Correlation ◽  
The Southern Urals ◽  
Positive Correlation ◽  
Fine Grained ◽  
Upper Riphean ◽  
Diagenetic Fluids ◽  
The Uk

Research subject. A study was conducted into the geochemical features of various lithotypes of carbonate rocks (granular and clastic limestones, limestones with planar, planar-columnar and columnar stromatolites) from the upper subformation of the Uk Formation. This formation crowns the Upper Riphean Karatau Group on the Western slope of the Southern Urals (Bashkir meganticlinorium). Material and methods. The research material was two collections of carbonate rocks (11 and 32 samples), the general geochemical features of which were previously considered in publications in 2019. The main research method was the analysis of the correlation relationships of the main rock-forming components, trace elements and their indicator relationships. Research results. It was established that all lithotypes are characterized by a significant content of both the main rock-forming components and the trace elements that make up the insoluble residue/fine-grained terrigenous admixture. This suggests that the area of accumulation of carbonate sediments was located near the continent, which served as a source of a significant amount of fine-grained/clay suspension. Conclusions. A strong positive correlation was observed between K2O and REE in the carbonate rocks of the Upper Uk Subformation, and a strong negative correlation was observed between REE and CaO. This suggests that the REE content in carbonate rocks is controlled mainly by terrigenous/clay admixture. A positive correlation is also observed between REE and Th, Zr, and Al2O3. All this shows that REE in carbonate rocks are mainly present in clay admixtures. The correlation coefficient between Ce/Ce* and (Dy/Sm)N is 0.20, while this coefficient for Eu/Eu* and (Pr/Sm)N equals 0.12. Thus, a definite conclusion about the effect of diagenetic fluids on the distribution of REE cannot be made. The data obtained show that the distribution of REE and Y in our collection of carbonate rocks of the Upper subformation of the Uk Formation of the Southern Urals is controlled mainly by clay admixtures.

Mössbauer characteristics, mineralogy and isotopic age (Rb-Sr, K-Ar) of Upper Riphean glauconites from the UK Formation, the southern Urals

2008 ◽  
Vol 16 (3) ◽  
pp. 227-247 ◽  
Author(s):  
T. S. Zaitseva ◽  
I. M. Gorokhov ◽  
T. A. Ivanovskaya ◽  
M. A. Semikhatov ◽  
A. B. Kuznetsov ◽  
...  
Keyword(s):  
Southern Urals ◽  
Isotopic Age ◽  
The Southern Urals ◽  
Upper Riphean ◽  
The Uk

scholarly journals Provenance reconstructions. Article 1. Mineralogical and petrographic approaches and methods

LITOSFERA ◽  
2020 ◽  
Vol 19 (6) ◽  
pp. 834-860 ◽  
Author(s):  
A. V. Maslov ◽  
O. Yu. Melnichuk ◽  
G. A. Mizens ◽  
Yu. V. Titov
Keyword(s):  
Lower Cretaceous ◽  
Southern Urals ◽  
Upper Devonian ◽  
Middle Urals ◽  
Research Subject ◽  
Upper Vendian ◽  
Upper Riphean ◽  
Lithostratigraphic Units ◽  
Sandstone Composition

Research subject. This is the first in the series of four articles, which aims to review existing provenance reconstruction tools.Methods and materials. The data obtained during evaluation of different sandstone allothigenous components was used as a basis for analysis. The data was collected from the Upper Riphean Zilmerdak Formation Bir’yan Member and the Upper Vendian Bassa Formation (Southern Urals); the Upper Devonian Kodinka and Ust’kodinka formations (Middle Urals); the Lower Cretaceous Sortym Formation (Western Siberian sedimentary megabasin, Bolshekhetskaya depression).Results. The sandstone composition patterns of the lithostratigraphic units under study allowed the most common provenance features to be established by means of comparing data obtained by various diagrams.Conclusions. It is established that only the Kodinka, Ust’kodinka and Sortym sandstone compositions can be used as a source for rock reconstruction analysis, while the Bir’yan and Basa sandstone compositions have undergone massive transformations. 

Late Wisconsinan glacial stratigraphy and history of southeastern Manitoba

1980 ◽  
Vol 17 (1) ◽  
pp. 19-35 ◽  
Author(s):  
James T. Teller ◽  
Mark M. Fenton
Keyword(s):  
Carbonate Rocks ◽  
Lacustrine Sediment ◽  
Precambrian Rock ◽  
Lake Agassiz ◽  
Rock Fragments ◽  
Lithostratigraphic Units ◽  
Stratigraphic Position ◽  
History Of ◽  
International Boundary ◽  
Late Wisconsinan

The history of Late Wisconsinan glaciation in southwestern Manitoba has been established by identifying and correlating ice-laid lithostratigraphic units in the subsurface. Five Late Wisconsinan tills are defined on the basis of their texture, mineralogic composition, and stratigraphic position. These new formations are, from youngest to oldest, Marchand, Whitemouth Lake, Roseau, Senkiw, and Whiteshell Formations.Late Wisconsinan ice first invaded southeastern Manitoba 22 000 to 24 000 years ago. This Laurentide glacier advanced from the northeast across the Precambrian Shield and deposited the sandy Whiteshell and Senkiw tills, which contain abundant Precambrian rock fragments and minerals and few Paleozoic carbonate grains. Shortly after this, Keewatin ice advanced from the northwest over Paleozoic carbonate rocks, depositing the loamy carbonate-rich Roseau Formation throughout most of the area. This ice remained over southeastern Manitoba until after 13 500 years ago, when it rapidly retreated northward with Lake Agassiz on its heels. Two brief glacial readvances occurred. The first overrode Lake Agassiz lacustrine sediment as far south as central North Dakota shortly after about 13 000 years ago. The clayey Whitemouth Lake till was deposited in southern Manitoba at this time. After a rapid retreat, the ice briefly pushed southward over southeastern Manitoba about 12 000 years ago to just south of the International Boundary. The sandy carbonate-rich Marchand Formation was deposited at this time as the ice overrode its own sandy outwash. By 11 000 years ago, ice had disappeared from southeastern Manitoba.

The State of the Art in Management Education Applicable to Aerospace Activities

1967 ◽  
Vol 71 (677) ◽  
pp. 344-348
Author(s):  
J. V. Connolly
Keyword(s):  
Management Education ◽  
State Of The Art ◽  
Aerospace Industry ◽  
List Type ◽  
Industrial Training ◽  
The Past ◽  
The Subject ◽  
Economic Necessity ◽  
The Uk ◽  
The Impact

During the past two years, there has been a sharp acceleration to the interest which industry has displayed in the subject of management education. This can be attributed to these factors: —(a) A more widespread realisation of the gap developing between the UK and a number of foreign economies, as manifested by diverging rates of the major economic indicators.(b) The attainment of top-management responsibilities by a younger generation of managers, many of whom had been given some earlier training and who were more conscious of its value than the incumbents of the job from earlier generations.(c) The publication of the Franks, Robbins and (in the aerospace industry) the Plowden reports.(d) The impact of the Industrial Training Boards making it manifest, in terms of serious levies, that training was an economic necessity and therefore must be investigated thoroughly.Notwithstanding the widespread awakening of interest, it is very belated and sets numerous problems. The problems are in two areas—scale and quality.

Developments in Bulb Flats and Other Hot Rolled Special Steel Profiles for Advancing Commercial and Naval Shipbuilding in the U.S.

2000 ◽  
Vol 16 (04) ◽  
pp. 193-206
Author(s):  
Iain Braidwood ◽  
Geoff Lofthouse
Keyword(s):  
Composite Structures ◽  
State Of The Art ◽  
Construction Materials ◽  
Structural Performance ◽  
Life Cycle Costs ◽  
Naval Vessel ◽  
Special Steel ◽  
Steel Shapes ◽  
The Uk ◽  
Hot Rolled

Special steel profiles are increasingly being used for commercial and warship construction to reduce production and life cycle costs. In particular, bulb flats (Holland profiles), manufactured by special profiles businesses, are increasingly being used for plate stiffening in warships and naval auxiliaries. Examples are the UK's Type 23 Frigates, the LPH HMS Ocean, Watson Class Sealift ships and the Dutch LPD HrMs Rotterdam, as well as, looking to the future, the UK Type 45 Destroyer. Some comparison will be made of naval vessel construction on both sides of the Atlantic, particularly looking at the advantages that bulb flats can bring to naval vessel construction. This paper will discuss the challenge of introducing new shapes, examine the state of the art in the production of special steel shapes and describe metallurgical developments that enable the delivery of shapes with required structural performance and suitability for production. Shipbuilding developments such as laser welding are being addressed with a view to the manufacture of special profiles, particularly where tolerance and chemical composition issues need to be addressed. Future lightweight vessel construction may involve a mix of aluminium, steel and composite structures. Special profiles can be developed to assist in the joining of these different construction materials.

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