Yanshanian Mineralization of Zhaojinggou Nb-Ta Deposit, Inner Mongolia:Evidences from the Monazite and Zircon LA-MC-ICP-MS U-Pb and Biotite 40Ar-39Ar Geochronology
Li Zhidan
Li Xiaoguang
Cui Yurong
Li Guozhan
Zhang Jia
Guo Hu
Liu Wengang
Zhang Chao
Yu Reng'an
Xie Yu
Wang Jiaying
Abstract：The Zhaojinggou Nb-Ta deposit is a newly explored large-scale deposit in Wuchuan County, Inner Mongolia.The NbTa orebody is mainly hosted in the amazonite-bearing albite granite, and partly hosted in the granite aplite, greisen and amazonite granite pegmatite.In this paper, we use monazite and zircon LA-MC-ICP-MS U-Pb and biotite 40 Ar-39 Ar dating methods to constrain the mineralization age.Monazite LA-MC-ICP-MS U-Pb geochronological dating of four samples from granites yields ages of 124±2Ma (MSWD=2.9, n=27) , 124±3Ma (MSWD=2.0, n=46) , 121±1Ma (MSWD=3.3, n=43) and124±2Ma (MSWD=3.2, n=12) .One zircon sample from albite granite yields age of 125±1 Ma (MSWD=1.6, n=18) .Meanwhile, biotite 40 Ar-39 Ar dating obtains the plateau age of 133.84±0.79 Ma (MSWD=3.31) , isochron age of 134.55±0.79Ma (MSWD=1.93) and reverse isochron age of 134.58±0.80 Ma (MSWD=1.99) .Therefore, all these ages constrain that the ore-forming period of Zhaojinggou Nb-Ta deposit is Early Cretaceous.In conclusion, the Zhaojinggou deposit resulted from the tectonic-magmatic activities of extensional setting, and the Yanshanian Period is the main Nb-Ta metallogenic age in Inner Mongolia.
Keywords：Nb-Ta depositmineralization agemonazite and zircon U-Pb datingbiotite 40Ar-39Ar datingZhaojinggouInner Mongoliaisotope
Publication Date：2019-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 234-247 )