scholarly journals Extreme values of fold-related shortening in the hinterland structure of the Shilbilisaj section in the Talas Ridge (Tien Shan)

2020 ◽  
Author(s):  
Fedor Yakovlev ◽  
Krzysztof Gaidzik ◽  
Viacheslav Voytenko ◽  
Natalia Frolova
Keyword(s):  
Cross Sections ◽  
Extreme Values ◽  
Sedimentary Cover ◽  
Selection Procedure ◽  
Morphological Type ◽  
Tien Shan ◽  
Special Method ◽  
Reconstruction Method ◽  
Current Profile ◽  
Strain Ellipsoid

<p>Talas Ridge forms the western part of the Tien Shan Caledonian structure. The sedimentary cover shows a thickness of about 10 km and consists of carbonate flysch and para-platform deposits metamorphosed under greenschist and lesser grade. This structure relates to the "hinterland" tectonic type, characterized by the abundance of many small and moderate-sized folds of the "similar" morphological type. Conventional cross-section balancing techniques developed for "foreland" structures, with large "parallel" folds cannot be applied correctly to such complicated structures. Thus, a special method based on the "geometry of folded domains" was developed for balancing of "hinterland" structures. To test the proposed method, we choose the westernmost Shilbilisaj profile of the Talas Ridge that consists of a large number of folds.</p><p>The proposed approach is based on the hierarchical system of hinterland fold structures, and on the accordance of the “folded domain” deformation to the strain ellipsoid, as described in detail in F. Yakovlev [2017]. On the first step the detailed structural profile is divided into a number of domains, 0.5-1 km wide; each domain consists of several folds of almost the same morphology. Consequently, a number of morphological parameters are measured, together with the axial surface dip angle and the interlimb angle that allow the construction of a strain ellipsoid for each domain. The core of the reconstruction method consists of three consecutive kinematic operations: 1) rotation, 2) horizontal simple shearing, and 3) horizontal stretching. As a result, a pre-folded form of a domain is produced, characterized by length and tilting of a domain segment that differ from the current profile parameter values. Sequential aggregation of all pre-folded domains leads to a complete pre-folded profile that allows the calculation of its shortening value. In the next step a few "structural cells" with a length approximately equal to the sedimentary cover thickness, are selected that combine several pre-folded domains. Taking into account the pre-folded and current lengths of such cells, their shortening values are determined. In the system of hierarchy of folded structures, folded domains and structural cells (and its strain parameters) belong to the third and fourth levels, respectively.</p><p>The first three project participants restored the structure of the section independently, starting with the domain selection procedure. The preliminary estimates of the shortening of the entire profile obtained by participants were close to each other and very high (K=L0/L1, where K – shortening value, L0, and L1 – pre-folded and current length in km, respectively): 4.49=118.5/26.4; 4.29=114.0/26.6; 4.67=119.1/25.5. The first participant allocated 63 domains and 12 structural cells, based on the thickness of the sedimentary cover. The shortening values for these cells varied along the profile from high in the southern cells to relatively small in the center and again to high in the northern parts (K=5.20, 4.47, 4.27, 3.79, 3.86, 3.93, 4.24, 4.91, 4.74, 5.53, 4.84, 4.9).</p><p>Yakovlev F.L. 2017. Reconstruction of folded and faulted structures in zones of the linear folding using structural cross-sections. Moscow, Published in IPE RAS, 60 p.</p>

scholarly journals Mass-balance variability as a base for interpreting ice-core data

1995 ◽  
Vol 21 ◽  
pp. 201-205
Author(s):  
V. N. Mikhalenko
Keyword(s):  
Mass Balance ◽  
Extreme Values ◽  
Ice Core ◽  
Ice Cores ◽  
Tien Shan ◽  
Glacier Mass Balance ◽  
Similarity Type ◽  
Glacier System ◽  
Point Analysis ◽  
Drilling Site

The spatial extrapolation of data from ice cores depends on the complexity of the glacier system where the drilling site is located. The correlation between net mass balance, bn, of a specific point and of the whole glacier is different for each point. Analysis of net mass balance of Tuyuksu glacier in the Tien Shan, central Asia, confirms that the distribution of mass balance with height is more-or-less constant from year to year except in years with extreme values bn. Two types of “similarity” are described, additive and multiplicative. The “similarity” changes gradually from additive at the peripheral parts of the Tien Shan to multiplicative in the most continental central and eastern parts. Glacier mass-balance fluctuations of the frontal ridges are connected to the oscillations of accumulation and consequently to precipitation. Where the climate is more continental the mass-balance variability depends much more on the melting conditions than on accumulation. For the spatial interpretation of ice-core drilling results, a special analysis of “similarity type” is necessary. It allows the fixing of the spatial borders of the glacier system for which the dhilling site is representative.

scholarly journals GEOLOGICAL AND GEOPHYSICAL CHARACTERISTICS OF THE ANABAR‐KHATANGA OIL AND GAS PROVINCE; NUMERICAL MODELING OF THE PROCESSES OF FORMATION OF SALT DOMES (SIBERIAN SECTOR OF THE RUSSIAN ARCTICS)

2019 ◽  
Vol 10 (2) ◽  
pp. 459-470
Author(s):  
V. A. Kontorovich ◽  
В. V. Lunev ◽  
V. V. Lapkovsky
Keyword(s):  
Cross Sections ◽  
Oil And Gas ◽  
Numerical Models ◽  
Sedimentary Cover ◽  
Ground Surface ◽  
Geological Structure ◽  
Salt Domes ◽  
Software Packages ◽  
Geological Features ◽  
Gas Bearing

The article discusses the geological structure, oil‐and‐gas‐bearing capacities and salt tectogenesis of the Anabar‐Khatanga saddle located on the Laptev Sea shore. In the study area, the platform sediments are represented by the 14‐45 km thick Neoproterozoic‐Mesozoic sedimentary complexes. The regional cross‐sections show the early and middle Devonian salt‐bearing strata and associated salt domes in the sedimentary cover, which may be indicative of potential hydrocarbon‐containing structures. Diapirs reaching the ground surface can be associated with structures capable of trapping hydrocarbons, and typical anticline structures can occur above the domes buried beneath the sediments. In our study, we used the algorithms and software packages developed by A.A. Trofimuk Institute of Petroleum Geology and Geophysics (IPGG SB RAS). Taking into account the structural geological features of the study area, we conducted numerical simulation of the formation of salt dome structures. According to the numerical models, contrasting domes that reached the ground surface began to form in the early Permian and developed most intensely in the Mesozoic, and the buried diapirs developed mainly in the late Cretaceous and Cenozoic.

Selection of Best Smartphone Using Revised ELECTRE-III Method

2018 ◽  
Vol 17 (06) ◽  
pp. 1915-1936 ◽  
Author(s):  
I-Fei Chen ◽  
Ruey-Chyn Tsaur ◽  
Po-Ying Chen
Keyword(s):  
Extreme Values ◽  
Selection Procedure ◽  
Communication Tool ◽  
Quality Model ◽  
Respective Group ◽  
Electre Iii ◽  
The World ◽  
Feature Fatigue ◽  
Suitable Product ◽  
Selection Of

Since smartphones have become the most prevalent communication tool in the world, a wide variety of low-end to high-end smartphone products are currently available on the market. Choosing a suitable product becomes a challenge due to the problem of feature fatigue. This study developed a smartphone selection procedure for prospective users by incorporating ELECTRE-III method with Kano two-dimensional quality model. An empirical example of 15 smartphones from three different categories, namely, flagship, screen size and price, demonstrated that the credibility matrix of the revised ELECTRE-III had fewer extreme values (0 and 1) than its original counterpart. It was able to clearly distinguish the relative satisfaction of each option in the respective group, particularly for the tied products which could not be discerned by the original ELECTRE-III.

Denudation history of the French Massif Central: new insights from thermochronology, basement-basin cross-sections and semi-automated planation surfaces mapping

2020 ◽  
Author(s):  
Thomas François ◽  
Guillaume Baby ◽  
Paul Bessin ◽  
Julien Baptiste ◽  
Jocelyn Barbarand ◽  
...  
Keyword(s):  
Cross Sections ◽  
Sedimentary Cover ◽  
Fuzzy Classification ◽  
French Massif Central ◽  
Surface Mapping ◽  
Massif Central ◽  
Planation Surface ◽  
Surface Uplift ◽  
Source To Sink ◽  
Planation Surfaces

<p>Documenting surface uplift of basement areas is challenging, usually due to large gaps in the sedimentary record. In order to address this issue for the French Massif Central, we here investigate its denudation history through an integrated study that involves planation surface mapping, Apatite Fission-Track (AFT) Analysis and basement to basin cross-sections.</p><p>First, Planation surfaces were identified using a semi-automated fuzzy classification of pixels based on relationships between DEM derivatives (slope, curvature, ruggedness and incision) and field-recognized training samples.  Then, their different generations and age ranges were discriminated from hypsometry, fault partitioning and relationships with dated sedimentary and/or volcanic remnants, providing constraints on basement exhumation. Afterwards, integrating the previous planation surface analysis, geological cross-sections were produced from the Massif Central basement to the surrounding basins (Aquitaine Basin and Paris Basin). These sections provide local thicknesses estimates of the missing sedimentary cover over basement domains. Theses local thicknesses and exhumation phases were finally used as constraints to produce a thermal history modelling and a denudation map of different areas of the French Massif Central estimated from AFT inversion.</p><p>Our results show different burial and exhumation patterns with i) a main burial of its western parts (Limousin, Rouergue) during Jurassic times followed by an important regional denudation (1 to 2 km of missing cover and crystallized basement) during the early Cretaceous and ii) an Upper Cretaceous burial of its northeastern parts (Morvan, Forez) followed by an uppermost Cretaceous to Paleogene exhumation (<1 km of missing cover and crystallized basement). This further illustrates the different behavior of each units of the Massif Central during the Mesozoic to Cenozoic times. These results will ultimately be discussed and placed back into the western European deformation framework.</p><p> </p><p>(This work is founded and carried out in the framework of the BRGM-TOTAL project Source-to-Sink)</p>

Structure, strain and AMS of the Uzunakhmat thrust sheet (Talas Range, Kyrgyz North Tian Shan)

2020 ◽  
Author(s):  
Anastasia Kushnareva ◽  
Artem Moskalenko ◽  
Alexander Pasenko
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Structural Evolution ◽  
Middle Part ◽  
Tien Shan ◽  
Initial Shape ◽  
Thrust Sheet ◽  
Structural Style ◽  
Thrust Sheets ◽  
Tian Shan

<p>The Talas Range forms the northwest part of the Caledonides of the Northern Tian Shan. Based on differences in the structural style, metamorphism and sedimentary successions, three thrust sheets have been identified – the Uzunakhmat, Talas, and Kumyshtag thrust sheets. The Talas and Kumyshtag thrust sheets consist of Neoproterozoic-Ordovician terrigenous and carbonate rock units, whereas the Uzunakhmat thrust sheet consists of Neoproterozoic terrigenous rocks metamorphosed up to greenschist facies. The Uzunakhmat thrust sheet is separated from the Talas and Kumyshtag thrust sheets by the southwest-dipping Central Talas thrust (CTT). The dextral strike-slip Talas-Fergana Fault bounds the Uzunakhmat thrust sheet in the southwest. The main deformation events occurred in the Middle-Late Ordovician.</p><p>Structural and strain studies were done along profiles normal to the strike of folds and faults and located in the northwest and southeast parts of the Uzunakhmat thrust sheet. We also incorporate in our study structural profile in the central part of the Uzunakhmat thrust sheet, documented by Khudoley (1993) and Voytenko & Khudoley (2012).</p><p>The main strain indicators were detrital quartz grains in sandstones. Rf/φ and Normalized Fry methods were used to identify the amount of strain. Oblate ellipsoids predominate with Rxz values varying mostly from 1,6 to 2,4. Long axes of strain ellipsoids are sub-horizontal with the southeast to east-southeast trend. Similar trends have long axes of the anisotropy magnetic susceptibility ellipsoid being parallel to fold axes, cleavage-bedding intersection and mineral lineation as well as the trend of the major thrusts, including CTT.</p><p>The modern shape of the Uzunakhmat thrust sheet is similar to an elongated triangle, pinching out northwest and expanding southeast. Cross-section balancing corrected for the amount of strain shows along-strike decreasing of shortening in the southeast direction. Total shortening varies from 35% to 55% between sections located about 15 km from each other. Such significant variation in shortening corresponds to variation in structural style with much more tight folds and more numerous thrusts for cross-sections with a higher amount of shortening. However, the restored length of all cross-sections is quite similar pointing to the approximately rectangular initial shape of the Uzunakhmat thrust sheet. Our interpretation is that during the Caledonian tectonic events, the Uzunakhmat thrust sheet was displaced in the northwest direction with accompanied thrusting and folding of rock units within the thrust sheet. These deformations formed the modern shape of the thrust sheet in accordance with the amount of shortening detected by cross-section balancing. This interpretation also implies that modern erosion did not significantly affect shape of the Uzunakhmat thrust sheet formed after the Caledonian deformation.</p><p>Khudoley, A.K., 1993. Structural and strain analyses of the middle part of the Talassian Alatau ridge (Middle Asia, Kirgiystan). J. Struct. Geol. 6, 693–706.</p><p>Voytenko N.V., Khudoley A.K. Structural evolution of metamorphic rocks in the Talas Alatau, Tien Shan, Central Asia: Implication for early stages of the Talas-Ferghana Fault. // C. R. Geoscience. 2012. V. 344. P. 138–148.</p>

Balanced model of the folded sedimentary cover of the Greater Caucasus as a source of information about geodynamic processes on the scale of the lithosphere - statistical approach

2020 ◽  
Author(s):  
Evgenii Gorbatov ◽  
Fedor Yakovlev
Keyword(s):  
Factor Analysis ◽  
Sedimentary Cover ◽  
Special Method ◽  
Greater Caucasus ◽  
Folded Structure ◽  
Crust Layer ◽  
Geodynamic Processes ◽  
The Difference ◽  
Balanced Model ◽  
Uplift And Erosion

<p>Geodynamic processes of formation of mobile belts operate during entire tectonic cycle since sedimentation up to recent uplift and erosion. In general, we can expect that some quantitative parameters of tectonic events will be associated with such processes, so they can be used to solve the inverse problem of recognizing quantity and nature of geodynamic processes.</p><p>The Greater Caucasus is a well-studied Alpine structure, within which the sedimentary cover (total thickness of 10-15 km) has a thin layering, deformed in small and moderate-sized folds. The folded structure was described in 24 detailed profiles with a total length about 500 km. Using a special method of sections balancing, models of the sedimentary cover were compiled, based on the balance of the sediments volume and the shortening values. By the method, profiles were divided into 505 "folded domains", for which their pre-folded states were restored. Then, the pre-folded domains were combined into 78 "structural cells", for which their shortening values were estimated.</p><p>For calculations, a three-stage’s conditional model of the development of the Greater Caucasus was adopted: 1) sedimentation (Jurassic-Eocene), 2) shortening and folding formation (Oligocene), 3) uplift and erosion (post-Oligocene). Six parameters were digitized in the structural cells: the depth of the basement top for development stages (1, 3, 4), the shortening value (2), the amplitude of uplift and erosion (5), the difference between the depths of the basement top in stages 3 and 1 (6). Obviously, these parameters are directly related to geodynamic processes of the Greater Caucasus formation. The calculation of the correlation matrix showed the presence of such strong correlations between a numbers of parameters, which may have a genetic sense. Factor analysis was used to clarify all these relationships. It showed the presence of two well-defined factors that explain the main dispersion of the six parameters. Factor (process) F1 (named ISOSTASY) has a weight of 46.6%, the loads on parameters 1-6 were 0.790, -0.195, 0.665, 0.982, 0.005 and 0.853. Process F1 showed the dependence of the actual depth of the basement top (4) on its first value (1), which is clearly associated with isostasy and necessarily indicates an increase of the density of the crust rocks up to mantle values. The F2 factor (named SHORTENING) has a weight of 40.2%, the loads amounted to 0.022, 0.938, -0.736, -0.158, 0.957, -0.219. Factor (process) F2 indicated the dependence of the uplift amplitude (5) on the shortening value (2), which can also be associated with isostasy and changes in the density of the crust and mantle rocks.</p><p>The calculation of the crust layer thicknesses for a part of the structure during the development, in which it has an isostatic equilibrium, showed its gradual degradation from 40 km (before a sedimentation) to 14 km after sedimentation and to present 19 km after folding and uplift (9.5 km without shortening influence).</p><p>Yakovlev F.L., Gorbatov E.S., 2018. On using the factor analysis to study the geodynamic processes of formation of the Greater Caucasus. Geodynamics & Tectonophysics 9 (3), 909–926.</p>

Calculation of the Discharge through Øresund at the Drogden Sill by Measurements at two Fixed Stations

1995 ◽  
Vol 26 (3) ◽  
pp. 237-258 ◽  
Author(s):  
Flemming Jakobsen ◽  
Stéphane Castejon
Keyword(s):  
Cross Sections ◽  
Water Discharge ◽  
Current Profile ◽  
Interface Friction ◽  
Basic Assumptions ◽  
Energy Gradient ◽  
Close Relationship ◽  
Adcp Measurements ◽  
Channel Analysis ◽  
Relationship Of

The paper aims at relating the discharge through Øresund (the sound between Denmark and Sweden) to measured current and stratification at the two fixed stations Nordre Røse (St. 24) and Flinten SW (St. 21). The information on the discharge is gained from ship-based ADCP measurements carried out on board R/V Sensor. Close to the sill area, Saltholm island divides the flux into two parts: One part through the Drogden Channel (where St. 24 is located), and the other through the Flinten Channel (where St. 21 is located). The establishment of a relationship between discharge and current measurements at two fixed stations is based on three basic assumptions: 1) the stratification in the Drogden and Flinten channels is considered to be one- or two-layered; 2) the flow to be driven by a constant energy gradient across each channel; and 3) by simplifying the bathymetry of the cross-sections. The study of the water discharge through Øresund reveals a close relationship of hydrographic measurements (current profile, salinity profile and water level) at Nordre Røse (St. 24) and Flinten SW (St. 21). From the investigation an interface friction factor (fi/2) for the Drogden Channel is found to be 5.6 × 10−3. This value is applied for the Flinten channel analysis as well.

scholarly journals Selection of arbitrarily scaled cross-sections in bending stiffness design

2003 ◽  
Vol 217 (2) ◽  
pp. 113-125
Author(s):  
D Pasini ◽  
D J Smith ◽  
S C Burgess
Keyword(s):  
General Solution ◽  
Cross Sections ◽  
Performance Index ◽  
Selection Procedure ◽  
Performance Indices ◽  
Cross Sectional ◽  
Buckling Instability ◽  
Stiffness Design ◽  
Selection Of

Performance indices can be used to model the relative structural efficiency of different cross-sectional shapes. Performance indices have been previously defined mainly for structural cross-sections that are scaled proportionally in size. This paper extends the method of performance indices by allowing scaling of cross-sections in any direction. A novel feature of the method described in this paper is the inclusion of the space envelope as a design parameter. The first part of the paper gives a derivation of the general solution for the performance index. The second part presents a graphical selection procedure and discusses the efficiency limits of cross-sections due to buckling instability. It concludes with a case study to demonstrate the method.

Friction and Heat Transmission Coefficients

1937 ◽  
Vol 137 (1) ◽  
pp. 165-194 ◽  
Author(s):  
W. F. Cope
Keyword(s):  
Reynolds Number ◽  
Friction Coefficient ◽  
Cross Sections ◽  
Extreme Values ◽  
Internal Surface ◽  
Working Fluid ◽  
Heat Transmission ◽  
Isothermal Conditions ◽  
Transmission Coefficients ◽  
Metal Pipes

The work described in the paper was carried out to determine simultaneously the friction and heat transmission coefficients of metal pipes of various cross-sections. A technique has been worked out and apparatus constructed for the simultaneous determination of the friction and heat transmission coefficients of the central portion of a pipe through which a fluid is flowing. With this apparatus, and with water as the working fluid, tests have been carried out upon a series of drawn copper pipes whose cross-sections varied from circular through square, to rectangular with sides in the ratio of 8/1; in addition two drawn brass pipes, one of which had had its internal surface artificially roughened, have been tested. The extreme values of velocity and Reynolds number are in the ratio of about 300/1; the maximum values being about 340 cm. per sec. (11 ft. per sec.) and 30,000 respectively. The friction coefficient of the rough pipe under isothermal conditions has been determined for values of the Reynolds number up to 50,000, using air as the working fluid. The observations made have been reduced by the method of dimensional analysis and the following conclusions drawn:— (1) That the results of the heat transmission tests on the various pipes can be correlated on the basis of the hydraulic diameter. (2) That an increase in friction coefficient is not necessarily accompanied by an increase in heat transmission coefficient. (3) That the friction coefficient under heat transmission conditions is the same as that under isothermal conditions if the viscosity in the former case is that pertaining to the wall temperature of the pipe.

Stability to Localized Modes for a Class of Axisymmetric Magnetohydrodynamic Equilibria

1972 ◽  
Vol 27 (1) ◽  
pp. 23-26 ◽  
Author(s):  
G. Küppers ◽  
H. Tasso
Keyword(s):  
Aspect Ratio ◽  
Cross Sections ◽  
Current Density ◽  
Current Profile ◽  
Localized Modes ◽  
Elliptical Cross ◽  
Magnetic Surfaces ◽  
Mhd Equilibria ◽  
Order Of Magnitude ◽  
Flat Current

Abstract Mercier’s criterion is computed numerically for an exact class of axisymmetric MHD equilibria having possibly elliptical cross sections and a flat current profile. The main result is that the toroidal current density and the plasma beta can be increased by one order of magnitude if a) the eccentricity of the magnetic surfaces, b) the poloidal current, and c) the aspect ratio are adequately chosen, and if the ellipses are vertical.

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