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Date submitted2021-04-15
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Date accepted2022-09-06
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Date published2023-10-27
Gold-rare metal and associated mineralization in the western part of Bolshevik Island, Severnaya Zemlya archipelago
The presented studies are aimed to determine the formation patterns of the gold-rare metal mineralization within one of the most inaccessible Arctic islands of the Russian Federation, Bolshevik Island of the Severnaya Zemlya archipela-go. The relevance of the work is determined by the high probability of discovering a significant in terms of metal reserves deposit, which is proved by many researchers on the example of known large deposits to be a typical feature of sites with gold-rare metal formation. Obviously, only the possibility of discovering and subsequent development of a deposit of a highly liquid type of mineral, gold, can ensure the profitability of mining production on Severnaya Zemlya. It is established that the main geological, mineralogical, and geochemical features of the gold-rare metal mineralization in the Kropotkinsko-Nikitinskaya metallogenic zone of Bolshevik Island correspond to that of similar ore sites in Russia and the world. The occurrences of other formation types revealed in this metallogenic zone suggest a certain zoning in their distribution: mineralization is located in the apical parts of granitoids and in the nearest halo of hornfelses. At a distance, with an exit from the hornfelsed zone, there are occurrences of a cassiterite-sulphide formation with elevated gold and silver content at the top of the ore column, together with an increased amount of polymetallic ores. Occurrences of gold-quartz and gold-sulphide-quartz formations are localized in fault zones, as a rule, farther from granitoids. The total vertical range of gold mineralization exceeds 300 m. The assignment of all types of mineralization in the Kropotkinsko-Nikitinskaya metallogenic zone of Bolshevik Island to a single hydrothermal process is emphasized by the similar isotope composition of lead galena from heterogeneous occurrences, which determines the age of all mineralization at 200-300 Ma.
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Date submitted2020-05-17
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Date accepted2020-10-05
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Date published2020-11-24
Geological structure of the northern part of the Kara Shelf near the Severnaya Zemlya archipelago according to recent studies
Until recently, the North of the Kara Shelf was completely unexplored by seismic methods. Seismic and seismo-acoustic data that have appeared in recent years have made it possible to decipher features of the regional geological structure. This study solves the urgent problem of determining the prospects for the oil and gas potential of the North Kara sedimentary basin. The relevance of the research is associated with determining the prospects of the oil and gas potential of the North Kara sedimentary basin. The aim of the study is to clarify the age of the reflecting horizons using data on the geology of the island, as well as to determine the tectonic position of the sedimentary cover and basement structures in the north of the Kara shelf. The sedimentary cover is divided into three structural levels: Cambrian-Devonian, Middle Carboniferous-Cretaceous, Miocene-Quarter. The Cambrian-Devonian complex fills the deep troughs of the North Kara shelf. The most noticeable discontinuity is the base of Carboniferous-Permian rocks, lying on the eroded surface of folded Silurian-Devonian seismic complexes. The blanket-like plate part of the cover is composed of thin Carbon-Quarter complexes. The authors came to the conclusion that the fold structures of the Taimyr-Severozemelskiy fold belt gradually degenerate towards the Kara sedimentary basin and towards the continental slope of the Eurasian basin of the Arctic Ocean. A chain of narrow uplifts within the seabed relief, which correspond to narrow anticlines is traced to the West of the Severnaya Zemlya islands. Paleozoic rocks have subhorizontal bedding further to the West, within the Kara shelf. Mesozoic folding in the North of the Kara Sea is expressed exclusively in a weak activation of movements along faults. At the neotectonic stage, the shelf near Severnaya Zemlya was raised and the Mesozoic complexes were eroded. The modern seismic activity of the North Zemlya shelf is associated with the ongoing formation of the continental margin.
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Date submitted2008-10-21
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Date accepted2008-12-25
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Date published2009-12-11
Comparative analysis of spiriferida complexes of the frasnian stage in the south of Novaya Zemlya and one-aged complexes of East-European platform and other districts
- Authors:
- D. V. Bezgodova
The Article contains a brief characteristic of spiriferida (brachiopod) complexes spread in the Frasnian sediments in the South of Novaya Zemlya, and their comparison with one-aged complexes of several regions of East-European platform, such as Main Devonian field, Central districts, the Volga-Urals region, South Timan, south-western districts and also outlying districts of the Kuznetsk coal basin and North-West of Russia.
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Date submitted2008-10-11
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Date accepted2008-12-21
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Date published2009-12-11
Cyclicity of the devonian and carboniferous deposits of Novaya Zemlya
- Authors:
- R. A. Schekoldin
Two structural-formational zones are recognized in the Devonian and Carboniferous deposits of Novaya Zemlya: the Barents zone and the Kara zone. The first one is characterized by thick, predominantly carbonate deposits, containing a rich complex of benthic fossils, and corresponds to the shelf paleoenvironments. The second one is characterized by thin hemipelagic argillaceous, lime and siliceous deposits, containing scarce pelagic fossils. This zone is suggested to represent bathyal paleoenvironments (slope and basin floor). The main control on sedimentation in both zones provided relative sea-level rises and falls, which repeated with mean periodicity equal to an age (third-order cycles). Sea-level highstands correspord to periods of low sedimentation rates and stagnation in deep-water zone. Sea-level lowstands were favourable to intensification of sediment gravity flows and better aeration of bottom waters.