Abstract
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 μm in size, enclosed by albite, K-feldspar, and quartz. Type-II zircons occur as subhedral to euhedral 20–150 μm 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 μm 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.
Highlights
A-type peralkaline granitic rocks are characterized by high FeO/MgO, K2 O/Na2 O ratio, low CaO, Al2 O3 and H2 O, high concentration of high field strength elements (HFSE) and rare earth elements (REE) [1]
High concentrations of HFSE and REE in peralkaline granitic rocks have been reported from many igneous complexes such as Strange Lake, Canada [2], Bokan Mountain, USA [3], Midian Mountains, Saudi Arabia [4], and Khaldzan Burgedei, Mongolia [5] etc
Ramanspectra spectrashow show three type zircons have a damaging of radiation
Summary
A-type peralkaline granitic rocks are characterized by high FeO/MgO, K2 O/Na2 O ratio, low CaO, Al2 O3 and H2 O, high concentration of high field strength elements (HFSE) and rare earth elements (REE) [1]. High concentrations of HFSE and REE in peralkaline granitic rocks have been reported from many igneous complexes such as Strange Lake, Canada [2], Bokan Mountain, USA [3], Midian Mountains, Saudi Arabia [4], and Khaldzan Burgedei, Mongolia [5] etc. In these igneous complexes, HFSE and REE mineralization have been considered to be formed by magmatic fractionation [2,5,6,7], metasomatic alteration, low temperature external hydrothermal fluids involvement [8], and/or a mixture of these processes [2,9,10,11].
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
