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Vol. 18 (2015 year), No. 2

Miroshnikova Ya. A., Pakhomovsky Ya. A.
Vein bodies in the "Moroshkovoe Lake" target (Monchegorsk area) and related mineralization

The paper presents the results of petrographic and mineragenous studies of main rock and ores varieties of the "Moroshkovoe Lake" target (south-eastern part of the Monchepluton). It has been found that the area composed the massive norites and metanorites crossed by veins of two types: 1) with noritic composition; 2) with amphibole-plagioclase composition. The studies have found an association of different types of veins with different ore mineralization. Sulfide, oxide and PGE mineralization is associated with the vein bodies of the first type. The veins of the second type do not contain PGE mineralization: ore minerals are mostly chalcopyrite and to a lesser extent are represented by Pb and Zn sulfides

(in Russian, стр.7, fig. 3, tables. 2, ref 5, Adobe PDF, Adobe PDF 0 Kb)

Vol. 25 (2022 year), No. 1, DOI: 10.21443/1560-9278-2022-25-1

Miroshnikova Ya. A.
Vein formation of the Monchepluton and the Monchetundra intrusion contact zone

The Monchegorsk region (Kola Peninsula) is distinguished by its platinum metal specialization and is a promising target for prospecting and exploration of valuable, strategically important platinum group metals. In the course of the study, the petrographic, petrochemical, and geochemical features of the vein bodies in the junction zone of large Early Proterozoic layered intrusions (the Monchegorsk pluton and the Monchetundra intrusion) have been characterized. Vein bodies are observed within the South Sopchinsky massif and the Moroshkovoe Lake massif. The veins are located near the contact of fine-medium-grained metapyroxenites (metanorites) and coarse-grained gabbronorites. Two main types of veins are identified: 1) veins of plagioclase-pyroxene and plagioclase-amphibole composition and 2) veins of quartz-feldspar and amphibole-plagioclase composition. Analysis of the content of chalcophilic elements in this area rocks has shown that the increased content of platinum group elements is associated with the first type of vein formations. Vein rocks of plagioclase-pyroxene and plagioclase-amphibole composition (type 1) contain on average Cu – 0.22 %, Ni – 0.11 %, ?PGE – 1 g/t, Au – 0.042 ppm. Vein rocks of quartz-feldspar and amphibole-plagioclase composition (type 2) contain on average Cu – 0.04 %, Ni – 0.01 %, ?PGE – 0.05 ppm, Au – 0.012 ppm. The distribution spectra of rare-earth and rare elements in the vein rocks of the South Sopchinsky massif and the Moroshkovoe Lake massif show both the commonality of all types of veins and the regular nature of differences in the composition of the veins.

(in Russian, стр.11, fig. 6, tables. 0, ref 18, AdobePDF, AdobePDF 0 Kb)

Vol. 25 (2022 year), No. 1, DOI: 10.21443/1560-9278-2022-25-1

Neradovsky Yu. N., Miroshnikova Ya. A., Companchenko A. A., Chernyavsky A. V.
About terraces on the shore of the Teriberskaya Bay of the Barents Sea (the Kola Peninsula)

The paper considers the results of the study of modern terraces on the coast of the Lodeyny Peninsula in the Barents Sea. According to field observations, decoding of space and geodetic maps and volumetric modeling, signs of three terraces have been identified. Two terraces having a rear seam, a cliff, a brow and horizontal platforms have been studied in more detail. The rear seams are located at 7 and 30 m, and the edges at 10 and 40 m above the sea level. The third terrace is confined to the level of 40–60 m, and has not been studied in detail. According to estimates, the first two terraces were formed about 3,300 and 6,000 years ago respectively. The 1st terrace characterizes the period of slow land rise by 10 m, at the speed up to 3 mm/year, which began about 3,300 years ago and continues to the present. It is characterized by a uniform sea retreat of about 15 mm/year. The erosion products of this terrace are common in the lateral zone and represent modern marine sediments, including beaches forming a new terrace. The 2nd terrace characterizes to the dynamics of rapid land rise by 30 m at a speed of about 11 mm/year, which occurred in the period from 6,000 to 3,300 years ago. The erosion products of this terrace are most common on the coast and are found at a distance of 100 m to 2–3 km from the shore. It is assumed that the speed of movement of the coastline during the retreat of the sea was different and reached up to 900 mm/year. According to the authors, preliminary data indicate the instability of the territory and the manifestation of block movements, which may have a negative impact on the development of infrastructure.

(in Russian, стр.12, fig. 14, tables. 0, ref 17, AdobePDF, AdobePDF 0 Kb)