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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 submitted2022-03-03
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Date accepted2022-04-27
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Date published2022-07-26
Peculiarities of rare-metal mineralization and genetic relationship of mineral associations in the eastern rim of Murzinsko-Aduysky anticlinorium (the Ural Emerald Belt)
- Authors:
- Mikhail P. Popov
The paper presents features of the location and composition, as well as a generalization of data on the age of rare-metal mineralization developed at the deposits and occurrences of rare metals and gemstones in the eastern rim of Murzinsko-Aduysky anticlinorium, within the Ural Emerald Belt, which is a classic ore and mineralogical object and has been studied for almost two hundred years. With a significant number and variety of prospecting, research and scientific works devoted mainly to emerald-bearing mica complexes and beryl mineralization, as well as rare-metal pegmatites, scientific literature has so far lacked generalizations on the formation of numerous mineral associations and ore formations that represents a uniform genetic process in this ore district. The aim of the work is a comprehensive geological-mineralogical analysis of mineral associations of the eastern rim of Murzinsko-Aduysky anticlinorium and studying their age, formation conditions and characteristic features to determine the possibility of expanding and using the mineral resource base of the Urals through developing new prognostic and prospecting criteria for rare-metal and gemstone ore formations and creating the new devices for promising objects prospecting
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Date submitted2020-08-20
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Date accepted2021-11-30
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Date published2021-12-27
Indicator role of rare and rare-earth elements of the Northwest manganese ore occurrence (South Africa) in the genetic model of supergene manganese deposits
- Authors:
- Aleksandr N. Evdokimov
- Benedict L. Pharoe
The authors analyzed the content of a number of rare and rare-earth elements in the rocks of the Northwest manganese ore occurrence, confined to the Neoarchean dolomites of the Malmani series of the Transvaal Basin. 30 samples of manganese ores and host rocks were analyzed by ICP-MS and XRF methods. Average values of Post-Archean Australian Shale (PAAS) were used as the geochemical standard for data calculation and normalization. The concentrations of elements normalized on PAAS reveal the LREE anomaly in manganese ores. Positive Ce and negative Y–anomalies indicate the hydro-genetical type of sedimentation of ore minerals from manganese-bearing aqueous solutions. This is consistent with the ratios of the elements: Ce and Y SN /Ho SN , Ce and Nd, Fe – Mn – (Co + Ni + Cu) × 10. A clear correlation between the contents of rare-earth elements in manganese nodules and the underlying Malmani dolomites indicates their close genetic relationship. Negative Ce and positive Y–anomalies in manganese wad minerals indicate differences in the conditions of their formation. The manganese wad formed earlier than the rest of the ore with the active participation of microorganisms.