scholarly journals Geodynamic Evolution and Metallogeny of Archaean Structural and Compositional Complexes in the Northwestern Russian Arctic

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 573 ◽  
Author(s):  
Nikolay E. Kozlov ◽  
Nikolay O. Sorokhtin ◽  
Eugeny V. Martynov
Keyword(s):  
General Scheme ◽  
Linear Process ◽  
Northwestern Part ◽  
Russian Arctic ◽  
Geodynamic Evolution ◽  
Early Precambrian ◽  
Precambrian Geology ◽  
Kola Region ◽  
Location Patterns ◽  
Geodynamic Reconstructions

This paper highlights the geodynamic evolution of the early Precambrian rock associations in the northwestern part of the Russian Arctic where the rocks are exposed in the Kola region (northeastern Baltic Shield). The evolution is shown to predetermine the metallogenic potential of the area. It is emphasized that the Earth’s evolution is a non-linear process. Thus, we cannot draw direct analogies with Phanerozoic time or purely apply the principle of actualism, which is still widely used by experts in Precambrian geology to study the premetamorphic history of ancient deposits. In both cases, the principles should be adjusted. This article provides a novel technique for reconstructing geodynamic regimes of protolith formation in the early Precambrian. The technique identifies changing trends in geodynamic regimes during the formation of the Archean structural and compositional complexes in the Kola region. These trends fit into the earlier suggested general scheme of their formation, thus enhancing its reliability. The metallogeny of the ore areas is specified. The results of the geodynamic reconstructions explain most of the location patterns of minerals within the Kola region. Thus, the authors consider the metallogenic forecast based on geodynamic reconstructions to be a promising trend for further research.

Suture zones and importance of strike-slip faulting for Variscan geodynamic reconstructions of the External Crystalline Massifs of the western Alps

2009 ◽  
Vol 180 (6) ◽  
pp. 483-500 ◽  
Author(s):  
Stéphane Guillot ◽  
Silvia di Paola ◽  
René-Pierre Ménot ◽  
Patrick Ledru ◽  
Maria Iole Spalla ◽  
...  
Keyword(s):  
Shear Zone ◽  
Bohemian Massif ◽  
Western Alps ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
Geodynamic Evolution ◽  
Central European ◽  
Back Arc ◽  
Eastern Domain ◽  
Geodynamic Reconstructions

Abstract This paper reviews the geodynamic evolution of the Belledonne, Grandes Rousses and Oisans massifs in the western Alps from Early Ordovician to Permian times. Three domains are distinguished. The eastern domain, which includes the NE Belledonne massif and the inner Oisans massif, records the subduction of the Central-European ocean along a NW dipping subduction zone. The western domain is marked by Cambro-Ordovician back-arc rifting (Chamrousse ophiolite) initiating the opening of the Rheic ocean. It was followed by Mid-Devonian obduction of the back-arc Chamrousse ophiolite, towards the NW in relation with the SE dipping subduction of the Saxo-Thuringian ocean. The central domain, including the SW part of the Belledonne massif, the Grandes Rousses massif and the outer Oisans massif, records the Devonian to Carboniferous orogenic activity that produced calc-alkaline magmatism, Mg-K granite intrusions and syn-collisional sedimentation related to Visean nappe stacking that we relate to the closure of the Saxo-Thuringian ocean. Based on tectonostratigraphic correlations we propose that these domains initially correspond to the northeastward extension of the Bohemian massif. During the late Carboniferous, the External Crystalline Massifs including Sardinia and Corsica were stretched towards the SW along the > 600 km long dextral External Crystalline Massifs shear zone. Offset of the Saxo-Thuringian and eo-Variscan suture zones from the Bohemian massif to the ECM suggests a possible dextral displacement of about 300 km along the ECM shear zone.

scholarly journals Geology, petrography and mineralogy of explosive breccias of Sallanlatva, Kola Region

Vestnik MGTU ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 57-68
Author(s):  
M. Yu. Sidorov ◽  
E. N. Kozlov ◽  
E. N. Fomina
Keyword(s):  
Mineral Composition ◽  
Great Depth ◽  
Northwestern Part ◽  
Wide Spread ◽  
Fracture Zones ◽  
Magma Chambers ◽  
Ree Mineralization ◽  
Kola Region ◽  
Hydrothermal Processes ◽  
Host Rocks

The Sallanlatva massif belongs to the group of Paleozoic alkaline-ultrabasic complexes wide spread in the Kola Region (the northwestern part of the Fennoscandian Shield). In the central part of this massif, the host ijolite and urtites contain calcite, ankerite, ankerite-dolomite and siderite carbonatites. The explosive processes that led to the formation of carbonatite breccias in the calcite and ankerite-dolomite carbonatites occurred in Sallanlatva massife in the last stages of the carbonatite magmatism. There are two types of explosive carbonatite breccias in the Sallanlatva massif: (1) glimmerite-calciocarbonatite breccias, and (2) siderite-dolomite breccias. Analysis of the mineral composition of fragments and matrix and the shape of fragments in breccias has shown that the first material to intrude into the host calcite and ankerite-dolomite carbonatites was calcite melt. After that, dolomite melt penetrated through the fracture zones, which resulted in the formation of siderite-dolomite breccias. The differences in the mineral composition of the breccia matrix suggest that the residual carbonatite melts originate from separate magma chambers. The chamber with calcite melt was located at great depth, and some captured glimmerite fragments were abraded during the melt upwelling. Silicate-dolomite melts lifted from a shallower depth; the captured fragments of siderite carbonatites retained their angular shape. Late hydrothermal processes yielded veins and caverns with Ba-Sr-P-S-Ti-REE mineralization in the breccias and host rocks.

scholarly journals Geodynamic Evolution of the Western Part of the Russian Arctic and Its Diamond Potential

Oceanology ◽  
2021 ◽  
Author(s):  
N. O. Sorokhtin ◽  
N. E. Kozlov
Keyword(s):  
Subduction Zones ◽  
Spatial Arrangement ◽  
Surface Boundary ◽  
Russian Arctic ◽  
Geodynamic Evolution ◽  
Near Surface ◽  
The Baltic ◽  
Diamond Potential ◽  
Diamondiferous Kimberlite ◽  
Calcite Carbonatites

Abstract The study of the geodynamic evolution of the Baltic Shield showed that the melts of diamondiferous kimberlites and related rocks were formed due to the pulling of “heavy” ferruginous sediments of the Early Proterozoic into subduction zones beneath the Archean cratons. Later, during the Neoproterozoic and Paleozoic stages of rifting, melts conserved in the lower crust and subcrustal lithosphere were able to penetrate into the near-surface zones of the crust and form magmatic complexes of alkaline–ultramafic and kimberlite magmatism. The authors showed that diamondiferous kimberlite and lamproite explosion pipes, as well as related carbonatite and alkaline–ultramafic intrusions, are mainly located above the subduction zones of the Svecofennian (Karelian) plates, which functioned about 2.0–1.8 Ga ago. At the same time, alkaline ultramafic intrusions and (sodium) carbonatites are located closest to the front of the subduction zone of Proterozoic plates (from 100 to 200–300 km). Then (at a distance of 200 to 400 km), there is a zone of location of calcite carbonatites and melilitites, and sometimes nondiamondiferous kimberlites. Diamondiferous kimberlite and lamproite diatremes are located farther than other similar formations approximately 300 to 600–650 km from its front. Such a regular spatial arrangement of magmatic complexes of a single series unambiguously indicates a change in depth of their origin. The farther from the surface boundary of the paleosubduction zone the magmatic bodies are located, the deeper the facies representing them.

scholarly journals Using Petrogeochemical Modeling to Understand the Relationship between Paleozoic Magmatism in the Kola Region and Its Precambrian History

Geosciences ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Nikolay E. Kozlov ◽  
Nikolay O. Sorokhtin ◽  
Eugeny V. Martynov
Keyword(s):  
Chemical Composition ◽  
Linear Trend ◽  
Alkaline Rock ◽  
Early Precambrian ◽  
Kola Region ◽  
Granulite Belt ◽  
Valuable Metals ◽  
Close Relationship ◽  
Lapland Granulite Belt ◽  
Unique Composition

The Kola region hosts numerous Paleozoic massifs of ultrabasic alkaline rocks and carbonatites with deposits of commercially valuable metals, such as iron, tantalum, niobium, and rare earth elements. These magmatic complexes are characterized by high contents of alkaline elements at generally low contents of SiO2 and/or Al2O3. In this study, we examined the precursors to the formation of the unique Paleozoic alkaline province through studying the early Precambrian stages in the evolution of the Kola collision area, from where these unique features probably originated. We mathematically modeled the changes in the chemical composition of these rocks. The obtained data can be used for metallogenic forecasting, which indicated a number of Precambrian objects in the region, namely, the Lapland Granulite Belt of the Kola region and granulite belts in Eurasia. The mathematical modeling performed during this research depicted a linear trend that defined the style of the changes in the chemical composition at the transition from the metaultrabasic-basic rocks of the Lapland granulite belt to the group of belts in Eurasia. These differences are statistically significant with respect to the obtained trend (chemical composition projected on the trend), mainly manifested as increased SiO2 and Al2O3 contents with a decreasing total alkalis content, which is opposite to the indicated trends of the changing chemical composition in the Paleozoic alkaline rock units of the Kola region. We concluded that one of the reasons for the unique composition of the Paleozoic magmatism products could be a specific feature of the earlier Neoarchean stages of the tectonic-magmatic activity in the northeastern Baltic Shield, which implies a close relationship between later geological events and the early Precambrian history, at least in the study area.

scholarly journals Geodynamic evolution and morphostructural analysis of the Western sector of the Russian Arctic shelf

Vestnik MGTU ◽  
2016 ◽  
Vol 19 (1/1) ◽  
pp. 123-137 ◽  
Author(s):  
N. O. Sorokhtin ◽  
◽  
S. L. Nikiforov ◽  
S. M. Koshel ◽  
N. E. Kozlov ◽  
...  
Keyword(s):  
Arctic Shelf ◽  
Russian Arctic ◽  
Geodynamic Evolution ◽  
Western Sector

scholarly journals Early Precambrian geology of the Godthåb area

1969 ◽  
Vol 19 ◽  
pp. 28-30
Author(s):  
V.R McGregor
Keyword(s):  
Geological Mapping ◽  
Early Precambrian ◽  
West Greenland ◽  
Precambrian Geology ◽  
The Town ◽  
Inner Parts

Work on the chronology of plutonic events in the Godthåb area, West Greenland, was continued in 1968. Geological mapping on a scale of 1:20 000 was extended to the islands south of the town of Godthåb and to the peninsula west and south of Kobbefjorden. In addition, short excursions were made to the islands between Godthåb and Færingehavn, to the southern part of the Nordland peninsula and to the inner parts of Godthåbsfjord.

Development of a State Tax Risk Management System

2020 ◽  
Vol 17 (6) ◽  
pp. 62-75
Author(s):  
A. V. Tikhonova
Keyword(s):  
Risk Management ◽  
General Scheme ◽  
Value Added ◽  
Comparison Method ◽  
The State ◽  
Scientific Methods ◽  
Traceability System ◽  
Road Map ◽  
State Tax ◽  
Presentation Methods

The article is devoted to the development of the concept of the state to manage its tax risks, based on a systematic approach. The author's concept presupposes the presence of the following elements logically arranged according to the principle "from the general to the particular": 1) mechanisms for managing tax risks, 2) disclosing methodological recommendations, 3) specific proposals for changing legislation. To achieve this goal, the author used general scientific methods (deduction and induction, analysis and synthesis, observation, description, generalization) and private scientific methods of cognition (comparison method, graphical and tabular data presentation methods). We have presented a brief overview of the main tax risks of the Russian Federation in the current economic environment, which are classified in four areas: 1) risks in the field of value added taxation; 2) risks in the field of taxation of profits and income; 3) risks, the source of which is Russia's membership in the Eurasian Economic Union; 4) customs risks. The author presents a general scheme of tax risk management by the state, which includes the context, goals and management strategy. The priority mechanisms for managing the tax risks of the state are formulated on the basis of the presented classification of tax risks. These areas include: introduction of an end-to-end product traceability system; substantiation of taxation methods; joint elimination of tax risks (Federal Tax Service, Federal Customs Service, Ministry of Labor, Federal Service for Financial Monitoring); optimization of tax administration costs on the part of both tax authorities and taxpayers; harmonization of indirect taxation, including duty-free trade; harmonization of international tax rules at the international level; selection of the most effective tools for eliminating multiple taxation. A draft "road map" has been developed to improve the management of state tax risks.

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