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Your search keyword '"Kotov, A.B."' showing total 35 results
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35 results on '"Kotov, A.B."'

32. Age of the Katugin Ta-Nb deposit, Aldan shield: evidence for a global rare-metal metallogenic epoch.

Author

Larin A.M., Knox-Robinson C.M., Kotov A.B., Kovach V.P., Longley-Sinitsyna D.A., Salnikova E.B., Larin A.M., Knox-Robinson C.M., Kotov A.B., Kovach V.P., Longley-Sinitsyna D.A., and Salnikova E.B.

Abstract

U-Pb dating of the Katugin peralkaline granite in Russia, to which it is suggested that rare-metal mineralisation was related, indicates a new rare-metal metallogenic epoch from about 2.2 to 2.05 Ga, linked to a global period of extension prior to early Proterozoic spreading and ocean formation., U-Pb dating of the Katugin peralkaline granite in Russia, to which it is suggested that rare-metal mineralisation was related, indicates a new rare-metal metallogenic epoch from about 2.2 to 2.05 Ga, linked to a global period of extension prior to early Proterozoic spreading and ocean formation.

33. Ore-bearing magmatism at the Ermakov beryllium deposit in the western Transbaikal region: age, magma sources and relations with ore mineralisation.

Author

Lykhin D.A., Kostitsyn Y.A., Kotov A.B., Kovach V.P., Kovalenko V.I., Ripp G.S., Salnikova E.B., Yarmolyuk V.V., Lykhin D.A., Kostitsyn Y.A., Kotov A.B., Kovach V.P., Kovalenko V.I., Ripp G.S., Salnikova E.B., and Yarmolyuk V.V.

Abstract

The deposit's geology is outlined, the radiometric dating of the various intrusive rocks discussed and the geochemistry at different sample points in the orebody tabulated. Early pre-ore granite dykes, intruding the host gabbro-diorites, are cut by second-stage basites and third-stage syenite-granite dykes of the same age as the ore mineralisation. The major- and rare-element compositions of the basites, syenites and granites are compared with those of the leucogranitic massif and the magmatic and ore-forming process discussed., The deposit's geology is outlined, the radiometric dating of the various intrusive rocks discussed and the geochemistry at different sample points in the orebody tabulated. Early pre-ore granite dykes, intruding the host gabbro-diorites, are cut by second-stage basites and third-stage syenite-granite dykes of the same age as the ore mineralisation. The major- and rare-element compositions of the basites, syenites and granites are compared with those of the leucogranitic massif and the magmatic and ore-forming process discussed.

34. Granitoids of the Yugodzur ore district (south-eastern Mongolia) and associated W-Mo mineralisation.

Author

Kovalenko V.I., Budnikov S.V., Kotov A.B., Kovach V.P., Salnikova E.B., Tsareva G.M., Yakovleva S.Z., Yarmolyuk V.V., Kovalenko V.I., Budnikov S.V., Kotov A.B., Kovach V.P., Salnikova E.B., Tsareva G.M., Yakovleva S.Z., and Yarmolyuk V.V.

Abstract

The Palaeozoic and Mesozoic granitoid intrusions are associated with the Yugodzyr Mo-W deposit and the Khaylias ore district plus a number of other tungsten or tin-tungsten occurrences. The Yugodzyr deposit consists of quartz-wolframite-molybdenite veins in Ordovician sediments surrounding a greisenised biotite-granite, while the Khaylias occurrences are associated with porphyritic granites of the Subshirotniy massif. The geochemistry of the Yugodzyr massif, Subshirotniy massif and adjacent Yuzhniy massif is compared and the results of Rb-Sr, U-Pb, Sm-Nd and Sr-Sr isotope studies are discussed., The Palaeozoic and Mesozoic granitoid intrusions are associated with the Yugodzyr Mo-W deposit and the Khaylias ore district plus a number of other tungsten or tin-tungsten occurrences. The Yugodzyr deposit consists of quartz-wolframite-molybdenite veins in Ordovician sediments surrounding a greisenised biotite-granite, while the Khaylias occurrences are associated with porphyritic granites of the Subshirotniy massif. The geochemistry of the Yugodzyr massif, Subshirotniy massif and adjacent Yuzhniy massif is compared and the results of Rb-Sr, U-Pb, Sm-Nd and Sr-Sr isotope studies are discussed.

35. Age, composition and sources of ore-bearing magmatism of the Orot beryllium deposit in western Transbaikalia, Russia.

Author

Lykhin D.A., Kotov A.B., Kovach V.P., Kovalenko V.I., Salnikova E.B., Yarmolyuk V.V., Lykhin D.A., Kotov A.B., Kovach V.P., Kovalenko V.I., Salnikova E.B., and Yarmolyuk V.V.

Abstract

The deposit lies in a graben that resulted from rifting during the early Mesozoic and contains a volcanic-intrusive suite of basalts and trachyrhyolites with granitoids. The deposit is hosted by effusive-breccia trachydacites and rhyolites that form part of the granotoid complex. Sampling found Be grades ranging from 3 087 to 8 616 g/t in the orebody, compared with 8.8-17.5 g/t Be in the adjacent granitoids 1-2 km away. The orebody was also enriched in SiO2, Fe2O3, Li, Th, U, Nb, Ta, Zr and V but depleted in alkaline elements, Ba, Cu, Ni and Cr. The geochemistry of the deposit and surrounding rocks is discussed in detail and compared with chondrite-normalised va;ues, while the results of isotope analysis are considered in relation to mid-ocea-ridge basalts, EM II enriched mantle and high U-Pb mantle., The deposit lies in a graben that resulted from rifting during the early Mesozoic and contains a volcanic-intrusive suite of basalts and trachyrhyolites with granitoids. The deposit is hosted by effusive-breccia trachydacites and rhyolites that form part of the granotoid complex. Sampling found Be grades ranging from 3 087 to 8 616 g/t in the orebody, compared with 8.8-17.5 g/t Be in the adjacent granitoids 1-2 km away. The orebody was also enriched in SiO2, Fe2O3, Li, Th, U, Nb, Ta, Zr and V but depleted in alkaline elements, Ba, Cu, Ni and Cr. The geochemistry of the deposit and surrounding rocks is discussed in detail and compared with chondrite-normalised va;ues, while the results of isotope analysis are considered in relation to mid-ocea-ridge basalts, EM II enriched mantle and high U-Pb mantle.

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