TY - JOUR

T1 - Mineralogy of phoscorites of the arbarastakh complex (Republic of Sakha, Yakutia, Russia)

AU - Kruk, Mikhail Nikolaevich

AU - Doroshkevich, Anna Gennadievna

AU - Prokopyev, Ilya Romanovich

AU - Izbrodin, Ivan Aleksandrovich

N1 - Funding Information: Funding: The investigations were supported by the Russian Science Foundation (RSF), project #19-17-00019. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/6

Y1 - 2021/6

N2 - The Arbarastakh ultramafic carbonatite complex is located in the southwestern part of the Siberian Craton and contains ore-bearing carbonatites and phoscorites with Zr-Nb-REE mineralization. Based on the modal composition, textural features, and chemical compositions of minerals, the phoscorites from Arbarastakh can be subdivided into two groups: FOS 1 and FOS 2. FOS 1 contains the primary minerals olivine, magnetite with isomorphic Ti impurities, phlogopite replaced by tetraferriphlogopite along the rims, and apatite poorly enriched in REE. Baddeleyite predominates among the accessory minerals in FOS 1. Zirconolite enriched with REE and Nb and pyrochlore are found in smaller quantities. FOS 2 has a similar mineral composition but contains much less olivine, magnetite is enriched in Mg, and the phlogopite is enriched in Ba and Al. Of the accessory minerals, pyrochlore predominates and is enriched in Ta, Th, and U; baddeleyite is subordinate and enriched in Nb. Chemical and textural differences suggest that the phoscorites were formed by the sequential introduction of different portions of the melt. The melt that formed the FOS 1 was enriched in Zr and REE relative to the FOS 2 melt; the melt that formed the FOS 2 was enriched in Al, Ba, Nb, Ta, Th, U, and, to a lesser extent, Sr.

AB - The Arbarastakh ultramafic carbonatite complex is located in the southwestern part of the Siberian Craton and contains ore-bearing carbonatites and phoscorites with Zr-Nb-REE mineralization. Based on the modal composition, textural features, and chemical compositions of minerals, the phoscorites from Arbarastakh can be subdivided into two groups: FOS 1 and FOS 2. FOS 1 contains the primary minerals olivine, magnetite with isomorphic Ti impurities, phlogopite replaced by tetraferriphlogopite along the rims, and apatite poorly enriched in REE. Baddeleyite predominates among the accessory minerals in FOS 1. Zirconolite enriched with REE and Nb and pyrochlore are found in smaller quantities. FOS 2 has a similar mineral composition but contains much less olivine, magnetite is enriched in Mg, and the phlogopite is enriched in Ba and Al. Of the accessory minerals, pyrochlore predominates and is enriched in Ta, Th, and U; baddeleyite is subordinate and enriched in Nb. Chemical and textural differences suggest that the phoscorites were formed by the sequential introduction of different portions of the melt. The melt that formed the FOS 1 was enriched in Zr and REE relative to the FOS 2 melt; the melt that formed the FOS 2 was enriched in Al, Ba, Nb, Ta, Th, U, and, to a lesser extent, Sr.

KW - Aldan shield

KW - Arbarastakh alkaline-ultrabasic carbonatite complex complex

KW - Chemical evolution

KW - Mineralogy

KW - Phoscorites

UR - http://www.scopus.com/inward/record.url?scp=85106268398&partnerID=8YFLogxK

U2 - 10.3390/min11060556

DO - 10.3390/min11060556

M3 - Article

AN - SCOPUS:85106268398

VL - 11

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 6

M1 - 556

ER -