TY - JOUR

T1 - Mineralogy and genesis of the FE-P-F-REE carbonatites of the central asian province

T2 - 20th International Multidisciplinary Scientific Geoconference: Science and Technologies in Geology, Exploration and Mining, SGEM 2020

AU - Prokopyev, Ilya

AU - Redina, Anna

AU - Potapov, Vladislav

AU - Doroshkevich, Anna

N1 - Funding Information: The mineralogical and fluid inclusion investigations were financially supported by a grant from the President of the Russian Federation МК-1113.2019.5. The work was done on state assignment of IGM SB RAS (0330-2016-0002). Publisher Copyright: © 2020 International Multidisciplinary Scientific Geoconference. All rights reserved. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2020

Y1 - 2020

N2 - Carbonatites are a unique group of magmatic rocks that contain extremely high concentrations and the world's largest reserves of rare earth elements, niobium, and a number of other industrial metals. The Late Mesozoic Central Asian carbonatite province includes three main regions: Western Transbaikalia, Central Tuva in Russia, and the South Khangai region in Mongolia. The carbonatites form deposits and occurrences of the complex Fe-P-F-(Ba)-(Sr)-REE ores. We studied and correlated the present data about mineral and physicochemical composition evolution in rocks, and provide the characteristics of the processes and fluid regime of the formation of the ore-bearing mineral assembleges of the carbonatites. The main magmatic ore phases are represented by magnetite and siderite (Fe), fluorapatite (P-REE), fluorite (F), and bastnaesite-(Ce) (REE), which were crystallized during fractional crystallization processes from carbonatitic melts at 790-890 °C. The ore-bearing hydrothermal mineral assembleges of carbonates and phosphates of REEs were monazite-(Ce), ancylite-(Ce), bastnaesite-(Ce), parisite-(Ce), synchysite-(Ce), hydroxyl-bastnaesite-(Ce), and the sulphates and carbonates of Ba and Sr-barite, celestite, and strontianite-were formed from the active brine melts of a carbonate-(fluoride)-phosphate-chloride-sulphate-CO2 composition at 680-520 °C. The latter hydrothermal mineralization of carbonates, fluorite, quartz, hematite, gypsum, and phosposiderite was produced from the hydro-carbonate-sulphate-chloride-CO2-H2-N2 fluids at 490-360, 310-275, and 250-100 °C.

AB - Carbonatites are a unique group of magmatic rocks that contain extremely high concentrations and the world's largest reserves of rare earth elements, niobium, and a number of other industrial metals. The Late Mesozoic Central Asian carbonatite province includes three main regions: Western Transbaikalia, Central Tuva in Russia, and the South Khangai region in Mongolia. The carbonatites form deposits and occurrences of the complex Fe-P-F-(Ba)-(Sr)-REE ores. We studied and correlated the present data about mineral and physicochemical composition evolution in rocks, and provide the characteristics of the processes and fluid regime of the formation of the ore-bearing mineral assembleges of the carbonatites. The main magmatic ore phases are represented by magnetite and siderite (Fe), fluorapatite (P-REE), fluorite (F), and bastnaesite-(Ce) (REE), which were crystallized during fractional crystallization processes from carbonatitic melts at 790-890 °C. The ore-bearing hydrothermal mineral assembleges of carbonates and phosphates of REEs were monazite-(Ce), ancylite-(Ce), bastnaesite-(Ce), parisite-(Ce), synchysite-(Ce), hydroxyl-bastnaesite-(Ce), and the sulphates and carbonates of Ba and Sr-barite, celestite, and strontianite-were formed from the active brine melts of a carbonate-(fluoride)-phosphate-chloride-sulphate-CO2 composition at 680-520 °C. The latter hydrothermal mineralization of carbonates, fluorite, quartz, hematite, gypsum, and phosposiderite was produced from the hydro-carbonate-sulphate-chloride-CO2-H2-N2 fluids at 490-360, 310-275, and 250-100 °C.

KW - Carbonatite

KW - Fluid inclusion

KW - Genesis

KW - REE

UR - http://www.scopus.com/inward/record.url?scp=85099769709&partnerID=8YFLogxK

U2 - 10.5593/sgem2020/1.1/s01.022

DO - 10.5593/sgem2020/1.1/s01.022

M3 - Conference article

AN - SCOPUS:85099769709

VL - 2020-August

SP - 171

EP - 178

JO - International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM

JF - International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM

SN - 1314-2704

IS - 1.1

Y2 - 18 August 2020 through 24 August 2020

ER -