REE-Nb MINERALIZATION IN TRACHYTES AND RHYOLITES OF THE KHULAM VOLCANO-PLUTONIC COMPLEX, NORTH CAUCASUS
The paper presents the first data on the composition of REE and Nb mineralization in the Middle Jurassic moderately alkaline felsic and moderately acid rocks of the Khulam volcano-plutonic complex at the territory of Kabardino-Balkaria, central part of Northern Caucasus. The igneous rocks of the Khu...
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South Urals Federal Research Center of Mineralogy and Geoecology UB RAS
2021-12-01
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Online Access: | https://journal.mineralogy.ru/wp-content/uploads/2021/12/2021_7_4_2.pdf |
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author | E.N. Kaigorodova O.A. Nabelkin P.M. Kartashov V.A. Lebedev |
author_facet | E.N. Kaigorodova O.A. Nabelkin P.M. Kartashov V.A. Lebedev |
author_sort | E.N. Kaigorodova |
collection | DOAJ |
description | The paper presents the first data on the composition of REE and Nb mineralization in the Middle Jurassic moderately alkaline felsic and moderately acid rocks of the Khulam volcano-plutonic complex at the territory of Kabardino-Balkaria, central part of Northern Caucasus. The igneous rocks of the Khulam Complex (intrusive and subvolcanic facies) belong to the contrasting differentiated bimodal association: (gabbro + basaltic trachyandesite) – (trachyte + rhyolite). Their main petrological and geochemical characteristics and ore mineralization are discussed. The trachytes and rhyolites of the Khulam Complex exhibit the high contents of Zr (up to 3100 ppm), Nb (up to 400 ppm), and ΣREE (>1000 ppm), which are caused by specific process of fractional crystallization of magmatic melts of elevated alkalinity during the formation of acid and moderately acid rocks. The Nb mineralization includes ilmenorutile and Nb-bearing brookite; REE minerals are monazite-(Ce), REE-bearing fluorapatite and REE fluorocarbonates of the bastnasite–vaterite homologous series. Monazite has magmatic origin and its formation is related to the enrichment of residual magmas in incompatible elements during fractional crystallization. The fluorocarbonates and ilmenorutile formed later as a result of autometamorphism and low-temperature hydrothermal alteration of felsic rocks. |
format | Article |
id | doaj-art-e03d55561a124393a5e120702bee6747 |
institution | Kabale University |
issn | 2313-545X 2782-2044 |
language | English |
publishDate | 2021-12-01 |
publisher | South Urals Federal Research Center of Mineralogy and Geoecology UB RAS |
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series | Минералогия |
spelling | doaj-art-e03d55561a124393a5e120702bee67472025-02-12T08:18:41ZengSouth Urals Federal Research Center of Mineralogy and Geoecology UB RASМинералогия2313-545X2782-20442021-12-0174334710.35597/2313-545X-2021-7-4-2REE-Nb MINERALIZATION IN TRACHYTES AND RHYOLITES OF THE KHULAM VOLCANO-PLUTONIC COMPLEX, NORTH CAUCASUS E.N. Kaigorodova0O.A. Nabelkin1P.M. Kartashov2V.A. Lebedev3Institute of Geology of Ore Deposits, Mineralogy, Petrography and Geochemistry RAS Institute of Mineralogy, Geochemistry and Crystal Chemistry of Rare ElementsInstitute of Geology of Ore Deposits, Mineralogy, Petrography and Geochemistry RASInstitute of Geology of Ore Deposits, Mineralogy, Petrography and Geochemistry RASThe paper presents the first data on the composition of REE and Nb mineralization in the Middle Jurassic moderately alkaline felsic and moderately acid rocks of the Khulam volcano-plutonic complex at the territory of Kabardino-Balkaria, central part of Northern Caucasus. The igneous rocks of the Khulam Complex (intrusive and subvolcanic facies) belong to the contrasting differentiated bimodal association: (gabbro + basaltic trachyandesite) – (trachyte + rhyolite). Their main petrological and geochemical characteristics and ore mineralization are discussed. The trachytes and rhyolites of the Khulam Complex exhibit the high contents of Zr (up to 3100 ppm), Nb (up to 400 ppm), and ΣREE (>1000 ppm), which are caused by specific process of fractional crystallization of magmatic melts of elevated alkalinity during the formation of acid and moderately acid rocks. The Nb mineralization includes ilmenorutile and Nb-bearing brookite; REE minerals are monazite-(Ce), REE-bearing fluorapatite and REE fluorocarbonates of the bastnasite–vaterite homologous series. Monazite has magmatic origin and its formation is related to the enrichment of residual magmas in incompatible elements during fractional crystallization. The fluorocarbonates and ilmenorutile formed later as a result of autometamorphism and low-temperature hydrothermal alteration of felsic rocks.https://journal.mineralogy.ru/wp-content/uploads/2021/12/2021_7_4_2.pdffluorocarbonatesrare earth elementsniobiumilmenorutilekhulam complexnorth caucasuskabardino-balkarian republic |
spellingShingle | E.N. Kaigorodova O.A. Nabelkin P.M. Kartashov V.A. Lebedev REE-Nb MINERALIZATION IN TRACHYTES AND RHYOLITES OF THE KHULAM VOLCANO-PLUTONIC COMPLEX, NORTH CAUCASUS Минералогия fluorocarbonates rare earth elements niobium ilmenorutile khulam complex north caucasus kabardino-balkarian republic |
title | REE-Nb MINERALIZATION IN TRACHYTES AND RHYOLITES OF THE KHULAM VOLCANO-PLUTONIC COMPLEX, NORTH CAUCASUS |
title_full | REE-Nb MINERALIZATION IN TRACHYTES AND RHYOLITES OF THE KHULAM VOLCANO-PLUTONIC COMPLEX, NORTH CAUCASUS |
title_fullStr | REE-Nb MINERALIZATION IN TRACHYTES AND RHYOLITES OF THE KHULAM VOLCANO-PLUTONIC COMPLEX, NORTH CAUCASUS |
title_full_unstemmed | REE-Nb MINERALIZATION IN TRACHYTES AND RHYOLITES OF THE KHULAM VOLCANO-PLUTONIC COMPLEX, NORTH CAUCASUS |
title_short | REE-Nb MINERALIZATION IN TRACHYTES AND RHYOLITES OF THE KHULAM VOLCANO-PLUTONIC COMPLEX, NORTH CAUCASUS |
title_sort | ree nb mineralization in trachytes and rhyolites of the khulam volcano plutonic complex north caucasus |
topic | fluorocarbonates rare earth elements niobium ilmenorutile khulam complex north caucasus kabardino-balkarian republic |
url | https://journal.mineralogy.ru/wp-content/uploads/2021/12/2021_7_4_2.pdf |
work_keys_str_mv | AT enkaigorodova reenbmineralizationintrachytesandrhyolitesofthekhulamvolcanoplutoniccomplexnorthcaucasus AT oanabelkin reenbmineralizationintrachytesandrhyolitesofthekhulamvolcanoplutoniccomplexnorthcaucasus AT pmkartashov reenbmineralizationintrachytesandrhyolitesofthekhulamvolcanoplutoniccomplexnorthcaucasus AT valebedev reenbmineralizationintrachytesandrhyolitesofthekhulamvolcanoplutoniccomplexnorthcaucasus |