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Chemical Characteristics of Zircon from Khaldzan Burgedei Peralkaline Complex, Western Mongolia Sarangua, Nergui Watanabe, Yasushi Echigo, Takuya Hoshino, Mihoko open access © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). zircon metasomatism Zr-Nb-REE mineralization A-type granite Khaldzan Burgedei The Khaldzan Burgedei peralkaline complex is one of the potential rare metal (Zr-Nb-REE) deposits in Mongolia. The complex consists mainly of quartz syenite and granite, and zircon is the most common accessory mineral in the rocks. Based on texture and mineral paragenesis, zircon is classified into three types. Type-I zircons in the quartz syenite and granite are generally isolated and euhedral to subhedral, 25-100 p.m in size, enclosed by albite, K-feldspar, and quartz. Type-II zircons occur as subhedral to euhedral 20-150 mu m grains, with quartz, and fluorite in the metasomatized zone in the quartz syenite as well as an upper part of the granite near the contact with the quartz syenite. These zircons contain porous core parts (Type-I) or remnants of corroded xenotime-(Y) and synchysite-(Ce). Type-III zircons are observed in the hydrothermally altered zone in quartz syenite and pegmatite. These zircons are anhedral, fine-grained, 10-30 mu m in size, and occur in amphibole pseudomorphs which were replaced by quartz, fluorite, chlorite, and hematite. Laser Raman spectra show that Type-I and Type-II zircons contain high amounts of water. Among these, three types of zircons, Type-II zircons are most enriched in REE, Nb, and Th. The texture and composition of the three types of zircons indicate that Type-I, Type-II, and Type-III zircons are magmatic, metasomatic and late hydrothermal in origin, respectively, and they experienced remobilization and recrystallization during the transition from a magmatic to a hydrothermal system. MDPI 2019 eng journal article VoR http://hdl.handle.net/10295/00006233 https://air.repo.nii.ac.jp/records/5921 https://doi.org/10.3390/min9010010 MINERALS 9 1 https://air.repo.nii.ac.jp/record/5921/files/kokuA_2022_8.pdf application/pdf 6.1 MB 2023-02-23