scholarly journals Fenite halos of linear carbonatite massifs: identification criteria and determination of geological structure

2015 ◽  
pp. 26-31
Author(s):  
S. Shnyukov ◽  
◽  
I. Lazareva ◽  
Yu. Nykanorova ◽  
◽  
...  
Keyword(s):  
Geological Structure

Oil production facilities management improving using the analogy method

2020 ◽  
pp. 42-50
Author(s):  
V.V. Mukhametshin ◽  
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Geological Structure ◽  
Oil Fields ◽  
Facilities Management ◽  
Analogy Method ◽  
Oil Reserves ◽  
High Degree ◽  
Production Facilities

For the conditions of an oil fields group characterized by an insufficiently high degree of oil reserves recovery, an algorithm for objects identifying using parameters characterizing the objects’ geological structure and having a predominant effect on the oil recovery factor is proposed. The proposed algorithm allows us to substantiate and use the analogy method to improve the oil production facilities management efficiency by targeted selection of the information about the objects and processes occurring in them, removing uncertainties in low density conditions, the emergence of real-time decision-making capabilities, determination of optimal ways of current problems solving, reducing the probability of erroneous decisions making, justifying the trend towards the goals achieving.

A Discussion on natural strain and geological structure - The control of ductility on the deformation of pebbles and conglomerates

1976 ◽  
Vol 283 (1312) ◽  
pp. 109-128 ◽  
Keyword(s):  
Confining Pressure ◽  
Geological Structure ◽  
Metamorphic Rocks ◽  
Tectonic Deformation ◽  
Low Grade ◽  
Rock Types ◽  
Gravitational Loading ◽  
The Matrix ◽  
Host Rocks

Pebbles are commonly used parameters for the determination of finite strain in deformed rocks. In high grade metamorphic environments, rocks probably behave as viscous fluids and a theory exists which relates the deformation experienced by a pebble to that of the host rocks. However, some deformed conglomerates are found in low grade metamorphic rocks where the assumption of viscous behaviour is unrealistic The deformation of artificial conglomerates made of geological materials, at room temperature and varying confining pressure is described. In these experiments, pebbles deform by cataclasis at surprisingly low applied loads and large finite strains are achieved. The amount of deformation experienced by pebbles of different rock types depends mainly on their yield strengths and ductility contrasts with respect to the matrix. A theoretical analysis assuming that pebble and matrix behave as workhardening Bingham materials during deformation relates the strain experienced by a pebble to that of the host rock. The results suggest that significant pebble deformation can occur during gravitational loading of sediments. An attempt is made to verify this idea by analysing the shape of pebbles in conglomerates of the Upper Witwatersrand System. At some sites the pebbles appear to have deformed during gravitational compaction while at others a tectonic deformation has been superimposed upon the pre-tectomic strain.

V.—On the Fossil Flora of the Staffordshire Coal Fields

1892 ◽  
Vol 36 (1) ◽  
pp. 63-98 ◽  
Author(s):  
E. Kidston
Keyword(s):  
Geological Structure ◽  
Fossil Flora ◽  
Fossil Plants ◽  
Coal Field ◽  
Geological Features ◽  
Relationship Of ◽  
Coal Measures ◽  
The Relationship ◽  
Coal Fields

The present paper is the second of the series dealing with the Fossil Flora of the Staffordshire Coal Fields. As in previous memoirs, I give a short sketch of the Geology of the coal field, merely for the purpose of indicating the relationship of the beds to each other, from which the fossils have been derived.Various memoirs dealing with the geological structure and resources of the Potteries Coal Field have already appeared, but in these the names applied to the different groups of strata which compose the Potteries Coal Field have generally special application to the local geological features, and do not treat of the Coal Field in its wider relationship, when considered as only forming a part of the Coal Measures as developed in Britain. A similar course has usually been taken in the published memoirs of other British Coal Fields, which makes a comparison of their relative ages, from the data given, very difficult.Although the Mollusea have usually been collected and examined, from their great vertical distribution—in some cases extending throughout the whole range of carboniferous rocks—they as a whole afford little data for the determination of the divisions of the Coal Measures, and unfortunately the fossil plants appear to have received little attention when the memoirs of the various coal fields were being prepared.

scholarly journals Ukraine in the history of the movement for the conservation of geological heritage in Europe

2020 ◽  
Vol 29 (1) ◽  
pp. 111-134
Author(s):  
Volodymyr V. Manyuk ◽  
Olesia V. Bondar ◽  
Oleh V. Yaholnyk
Keyword(s):  
Political System ◽  
Nature Reserve ◽  
Geological Structure ◽  
Geological Heritage ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
First Nature

The paper focuses on the history of the movement for preservation of geological heritage of Ukraine, closely related to the history of geoconservation in Europe; determines the relationship of the extent of geodiversity and geological structure of a certain country, political system, historical traditions and attitude towards wildlife and inanimate nature. Despite the fact that geodiversity and biodiversity have always been in parallel, traditionally all nations in all the continents have focused more on the preservation of so-called wildlife. The article describes that preservation of the so-called inanimate nature; provides a rather sufficient analysis of literature sources which report on the problem of preserving bio- and geodiversity not only in Ukraine, but also in other countries of Europe. In particular, the combination of biotic and abiotic constituents of nature proved to be an essential aspect in determining the place of the world`s first nature reserve and location of an important centre of Buddhism in Mihintale, Sri Lanka. The start of the movement for preservation of so-called inanimate nature in Europe could, with a certain extent of possibility, be considered the first historical written mention of the subject, which was declared in the 10th Chapter of Third Statute of Lithuania in 1588. That is protection of rivers against artificial change of their banks, change in currents and preservation of large erratic boulders. As an important stage of the beginning of the movement for preservation of the so-called inanimate, can be considered the year 1668, when in Germany the Baumannshöhle cave was preserved. It was first mentioned in the literature in 1565, and in 1646 the cave became an object of tourism. During the analysis of the historical stage related to the movement ProGEO, we emphasizes international events in which the representatives of the Ukrainian ProGEO group took part. Active work of the Ukrainian ProGEO group created conditions for transition to a new level of geoconservation, i.e. determination of the possibility of creating a new category of objects of the Nature-Reserve fund of Ukraine – geological parks (geoparks) as important locations for the development of geotourism and territories of complex conservation of the natural environment.

The digital zenith camera as an additional technique for quasi-geoid model determination of Latvia

2020 ◽  
Author(s):  
Katerina Morozova ◽  
Gunars Silabriedis ◽  
Ansis Zarins ◽  
Janis Balodis ◽  
Reiner Jaeger
Keyword(s):  
Geological Structure ◽  
Geopotential Model ◽  
Parametric Modelling ◽  
Vertical Deflection ◽  
Geoid Model ◽  
Star Catalog ◽  
Geopotential Models ◽  
Model Determination ◽  
The University

<p>The digital zenith camera VESTA (VErtical by STArs) was designed by the Institute of Geodesy and Geoinformatics (GGI) of the University of Latvia and completed in 2016. By 2020 more than 400 terrestrial vertical deflection measurements were observed in the territory of Latvia. These observations were post-processed by the GGI developed software and the accuracy was evaluated at 0.1 arc seconds. In 2019 two new cameras have been developed, which will be used in future projects, e.g., in determination of properties of local geological structure or Earth crust movement monitoring. Measurement control software corrections and complements, data processing improvements and automation and transition to GAIA data release 2 star catalog were done. The accuracy of the measurements of improved camera was evaluated at 0.05 arc seconds.</p><p>Terrestrial vertical deflection observations were compared with global geopotential models, e.g. GGM+ and EGM2008. The results show a better correspondence with GGM+ model by evaluating the standard deviation: 0.314 and 0.307 arc seconds for ξ and η components respectively in comparison to 0.346 and 0.358 arc seconds for ξ and η components for EGM2008 model. The comparisons of average and minimum/maximum differences are introduced in this study for better evaluation of the results. Moreover, vertical deflections have been used as additional terrestrial data in DFHRS (Digital Finite-element Height Reference Surface) software v. 4.3 in combination with GNSS/levelling data (B, L, hH) and global geopotential model EGM2008 for gravity field and quasi-geoid improvement (www.dfhbf.de). This approach is based on parametric modelling and computation of height reference surfaces (HRS) from geometric and physical observation components in a hybrid adjustment approach. The results of the computed quasi-geoid models using different types of data are introduced in this research, representing several solutions, as well as these solutions are compared with the national quasi-geoid model LV’14.</p>

ANALYSIS AND PROCESSING OF RECEIVED SIGNALS IN BOREHOLES

2001 ◽  
Vol 09 (02) ◽  
pp. 447-459 ◽  
Author(s):  
JENS M. HOVEM ◽  
HEFENG DONG ◽  
ODDVAR LOTSBERG
Keyword(s):  
Geological Structure ◽  
P Wave ◽  
Resonance Structure ◽  
Time Of Arrival ◽  
Reflected Waves ◽  
Sensor Signals ◽  
The Individual ◽  
Spatial And Temporal Characteristics ◽  
Plane P Wave

This study is a part of a project to develop a borehole sonar for acoustic imaging of the geological structure of the rock formation near to a deviated or horizontal borehole performed while drilling. The purpose of the sonar is to provide a direct measure of the distance and the direction to bed boundaries parallel to the borehole. This paper gives a theoretical analysis of the effect of the borehole and the drillstring on the received response on sensors positioned on the drillstring and proposes a method for processing the received signal to enable the determination of the direction of an incoming plane wave and time of arrival. In the first part of this paper, the response at any position in a fluid filled borehole is determined for an incoming plane P-wave. It is shown that the response is quite complicated and consists of several vibrating modes with resonance structure. Secondly, the paper presents how the received signals can be decomposed and the individual modes can be resolved by utilizing the orthogonal properties of the mode functions. The individual mode functions are resolved by performing a spatial Fourier transform of the sensor signals. A requirement is that the sensors are uniformly distributed around the circumference of the drillstring and that the number of sensors is at least two times the number of significant modes. It is demonstrated that the spatial and temporal characteristics of the resolved modes can then be exploited to determine the time of arrival and the angle of direction of the incoming reflected waves.

scholarly journals Morphostructure relations on the territory of the Republic of Serbia

2018 ◽  
Vol 98 (2) ◽  
pp. 1-28
Author(s):  
Ljubomir Menkovic ◽  
Milan Koscal ◽  
Milovan Milivojevic ◽  
Mrdjan Djokic
Keyword(s):  
Geological Structure ◽  
The Difference ◽  
The Republic ◽  
The Way

The paper presents author's views on morphostructural relations on the territory of the Republic of Serbia, which are presented graphically in the form of overview (reduced) morphostructural map in the scale of 1:2,000,000 to 1:2,500,000. The methodology of making morphostructural map, its content and the way of data pre-sentation was considered. Special attention has been paid to morphostructures, the determination of the origin and the difference between structural, morphostructural and morphosculpture relief forms. A brief overview of the geological structure, as well as the geomorphological characteristics of geotectonic, i.e. morphostructural units, is given. Finally, the geomorphological history, morphogenesis and the evolution of the relief of Serbia, from the beginning of the Miocene to the present is presented.

Determining seismic hazard in slowly deforming region: Can we gather enough information from karst caves?

2021 ◽  
Author(s):  
Ana Mladenović ◽  
Jelena Ćalić
Keyword(s):  
Seismic Hazard ◽  
Active Faults ◽  
Active Regions ◽  
Research Area ◽  
Geological Structure ◽  
Probabilistic Methods ◽  
Radiometric Dating ◽  
Southeastern Part ◽  
Karst Caves

<p>Methods to determine seismic hazard in any region vary depending on the regional seismicity, but can be roughly grouped into two main groups: one based on probabilistic methods that use data about known seismicity in the region, and another, which is based on data related to the faulting processes and determination of seismically active faults. Both groups of methods are relatively good for seismically active regions. However, in regions of low seismic activity and slow deformations, there is neither enough data for proper probabilistic determination of seismic hazard, nor enough data about deformation that can indicate possibly active faults. Because of that, all sets of data have to be combined in order to gather necessary information needed to determine seismic hazard for a given area.</p><p>One of such regions of low seismicity and very slow deformation is the region of Carpatho-Balkan orogen, situated in Eastern Serbia. This orogen represents the western part of the Carpatho-Balkan orogenic chain, extending in the north to the Romanian Southern Carpathians and in its southeastern part to the Balkan massif in Bulgaria. In its central part, in Eastern Serbia, Carpatho-Balkanides are made up of a system of east-vergent nappes, that have been formed in Early Cretaceous and were multiply activated during their geological history. This activity led to the formation of faults that are favorably oriented in respect to the main thrust system. It is suspected that some of these fault systems are also active in recent times.</p><p>Relatively complex geological structure and existence of a large number of rock discontinuities, as well as relatively long time during which these geological units have been exposed on the surface, led to intensive karst process and formation of both surface and underground karst forms. Therefore, investigations of faults and deformations on the field surface are very difficult, but investigations of neotectonically active faults inside the karst caves can give a lot more information.</p><p>In this abstract, we present evidence about the youngest and recently active faults in the region of interest, based on data from karst caves. Age of activity of faults mapped inside the caves was determined based on indicators of faults cutting speleothems, forming fault breccias that incorporate cave sediments (broken speleothems), and based on speleogenetic considerations. Samples for radiometric dating have been collected, that will help to quantify fault activity rate.</p><p>Preliminary results show that the research area is characterized by strike-slip tectonics, most likely resulting from far-field stress generated by the collision of the Adriatic microplate, the Moesian indenter and the tectonic units in-between. Such stress field is shown to be highly heterogeneous even in this relatively small research area, so local areas of transtension and transpression have also been very important in controlling the recent fault kinematics in this part of the Carpatho-Balkanides. These preliminary conclusions are also of high importance for seismic hazard characterization.</p>

Coroboration of magnetotelluric investigations with other geophysical anomalies for a case study located in North-West to central part of Romania

2020 ◽  
Author(s):  
Natalia-Silvia Asimopolos ◽  
Laurentiu Asimopolos
Keyword(s):  
Transition Zone ◽  
Sedimentary Cover ◽  
Careful Analysis ◽  
Geological Structure ◽  
North West ◽  
The North ◽  
The Many ◽  
Geophysical Anomalies

<p>The results of the magnetoteluric investigations carried out along the profiles are presented in the form of sections in which the variations of the different parameters, the 2-D modeling, as well as the inversions.</p><p>The results of the geophysical researches (magnetotellurics, gravity, geomagnetics) obtained were aimed at obtaining a unitary image on the deep geological structure in the investigated area. A number of information was obtained regarding such as:</p><ul><li>Determination of the thickness of the package of formations belonging to the post-tectogenetic sedimentary cover of the Transylvanian Depression; sedimentary sedimentary cover, conductive, with a maximum thickness of approximately 4000 m in the Pannonian Depression;</li> <li>Contouring of the Tethysian Major Suture (near the town of Alba Iulia in the Transylvanian Basin), represented by the Transylvanian nappes system (ofiolitic complex and sedimentary formations), with resistivities of about 500 Ohm*m, which separates two blocks with continental crust of different thicknesses (22- 27 km for Internal Dacids and 32-36 km for Median Dacids);</li> <li>Highlighting the change of nappes systems belonging to the Transylvanians, with a wide development both to the north (Căpâlnas-Techereu nappes and the nappes of Groşi and Criş), as well as to the east (the ophiolite complex and sedimentary cover), over the Biharia nappes system, respectively Central-Eastern Carpathian nappes; extension of the Codru and Biharia - Arieşeni nappes, the last with higher resistivities (200 Ohm*m);</li> <li>Highlighting the transcrustal fault that marks the contact between the Inner Dacides and the Median ones;</li> <li>Individualization at the level of the lower crust of a transition zone; significant decrease of resistivity, as a consequence of the presence of the fluids in the transition zone, from the pressure in the pores from lithostatic type to the hydrostatic type (occurs at depths of 22 - 30 km and at temperatures of 350º - 400º C).</li> </ul><p>The electromagnetic data reflect the anomalies of electrical conductivity in a sensitive way, but due to the many causes that can generate them, a careful analysis of the particularities existing for each case, especially the superficial ones, was necessary.</p><p>The correlation of the all the information provided in sections (resistivity, phases, density, magnetic susceptibility), inversions, modeling, lead to the validation of the model.</p>

scholarly journals The Tamunier gold deposit in the Northern Ural: Physicochemical formative conditions, ore and fluid sources, genesis

LITOSFERA ◽  
2019 ◽  
pp. 139-147
Author(s):  
D. A. Zamiatina ◽  
V. V. Murzin
Keyword(s):  
Genetic Model ◽  
Isotope Geochemistry ◽  
Geological Structure ◽  
Sulphide Ores ◽  
Formation Mode ◽  
Proposed Model ◽  
Volcano Plutonic Belt ◽  
Plutonic Belt ◽  
Fluid Formation

Research subject.This research study was aimed at investigating metasomatic minerals and ores in the Tamunier Deposit, which is located in the Northern Urals, at the Eastern side of the Tagil megazone within the Auerbach volcano-plutonic belt.Materials and methods.Well core samples were investigated using a complex of research methods, including optical and electron microscopy, X-ray spectral microanalysis, mineral geothermometry, thermobarogeochemistry (microthermometry, gas chromatography, determination of the salt composition of fluid inclusions in minerals) and isotope geochemistry (isotopes C, O, S, Sr, Pb).Results.A genetic model describing the formation of the Tamunier deposit was developed using the data obtained on its geological structure, mineral composition of metasomatites and ores, fluid formation mode, sources of ore matter and ore-bearing fluid. In the proposed model, the magmatogenic sodium chloride fluid carrying ore components and S is separated from the Auerbach complex at the depth of intrusion. Penetrating to the surface, this fluid interacts with the rocks of volcanic-sedimentary strata, thereby extracting a number of components, including CO2, S and Sr.Conclusion.Despite the presence of sulphide mineralization of hydrothermal-sedimentary genesis in the volcanogenic-sedimentary rock mass, the data obtained has allowed us to refer the gold-sulphide ores under study to magmatogenic-hydrothermal formations. The estimated P-T conditions (t= 100–370ºС andP= 0.4–0.6 kbar) and the shallow depth of the Tamunier field have shown its correspondence to the sub-epithermal level in the model of the porphyry-epithermal ore-magmatic system.

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