Geochronology and Geochemistry of the Xianghualing Granitic Rocks: Insights into Multi-Stage Sn-Polymetallic Mineralization in South China

• Published in: Minerals (Basel) Vol. 12; no. 9; p. 1091
• Main Authors: Luo, Zhaoyang, Li, Huan, Wu, Jinghua, Sun, Wenbo, Zhou, Jianqi, Maulana, Adi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2022
• Subjects: Aluminum oxide; Cretaceous; Dating; Fault lines; Fluids; Geochemistry; Geochronology; Geochronometry; Geology; Granite; Hydrothermal fields; Jurassic; Lava; Lead; Magma; Metallogenesis; Mineralization; Paleozoic; Petrology; Plate tectonics; Radiometric dating; Rock; Rocks; Silica; Silicon dioxide; Tin; Titanium dioxide; Trace elements; Triassic; Tungsten; Zircon; China
• ISSN: 2075-163X; 2075-163X
• DOI: 10.3390/min12091091

Multi-stage magmatic events associated with large tungsten-tin polymetallic deposits in the Nanling Range have been the subject of extensive research spanning many years. In this paper we report the results of a systematic study of the petrology, whole-rock geochemistry, zircon U-Pb chronology, and trace element geochemistry of granite bodies exposed in the Xianghualing ore field. They show that the granites in the study area are characterized by high SiO2 (63.83%–75.29%), Al2O3 (13.12%–18.87%), Rb (565–3260 ppm), Nd (67.3–113.5 ppm) and Ta (23.2–129.0 ppm) and by low MgO (0.02%–0.22%), TiO2 (0%–0.02%), Sr (5.3–80.5 ppm) and Ba (7.9–66.4 ppm). The rocks are highly differentiated A-type peraluminous granite, which originated in an extensional within-plate tectonic setting. Based on U-Pb dating and trace element analysis, the following multi-stage magma-hydrothermal events were identified: (1) Paleozoic (~347 Ma) and Triassic (~206 Ma) magmatic stages (initial enrichment epochs of ore-forming elements), (2) Jurassic (~161 Ma) magmatic-hydrothermal stage (mineralization epoch), and (3) Cretaceous hydrothermal overprinting stage (with peaks in the Early Cretaceous ~120 Ma and Late Cretaceous ~80 Ma). From an economic point of view, the Late Cretaceous appears to have great potential for tungsten-tin mineralization. Zircon trace element geochemistry indicates that the ore-forming fluids related to tin mineralization in the Cretaceous originated from the crust and underwent highly differentiated evolutionary processes under relatively reducing conditions. This paper emphasizes the Cretaceous tungsten-tin metallogenic events in the Nanling Range and provides an essential basis and new ideas for further tin-tungsten exploration.