Wall-rock Alteration and Element Fluxes in the Disuga Porphyry Cu Deposit, Northwest Yunnan Province, China, and Implications for Mineral Exploration
Lei MO , Chengbiao LENG , Xilian CHEN , Xingchun ZHANG , Kaixuan LI , Wenjie DUAN , Qianxin WANG , Sheng HUANG
Acta Geologica Sinica (English Edition) ›› 2025, Vol. 99 ›› Issue (5) : 1386 -1403.
The Disuga Cu deposit, located in the eastern porphyry belt of the Zhongdian arc, southwest China, provides a window into magmatic–hydrothermal processes controlling porphyry Cu mineralization. Based on zircon U-Pb geochronology, hydrothermal mineral chemistry, short-wave infrared spectroscopy, and mass balance modeling, this study investigated the alteration zonation and element mobility in the Disuga Cu deposit. Zircon U-Pb ages of the ore-hosting quartz dioritic porphyries (222.4 ± 3.1 and 219.3 ± 2.4 Ma) are similar to those of Late Triassic subduction-related magmatism. High zircon-crystallization temperatures (727 ± 26°C) and elevated oxygen fugacity (ΔFMQ + 2.0) confirm these porphyries were favorable for mineralization. Hydrothermal sericite (Si = 6.49 atoms per formula unit [apfu]; AlVI = 3.39 apfu) and chlorite (Fe/(Fe + Mg) = 0.59–0.63) compositions indicate an acidic reduced fluid. Three distinct hydrothermal stages were identified: (1) phyllic alteration (370°C); (2) propylitic alteration (315°C); and (3) low-temperature hydrothermal alteration (242°C). Mass balance calculations show that the Cu migration rate (155.6%/114.4%) in the propylitic/phyllic alteration zones was higher than that of Mo (14.3%; limited to the propylitic alteration zone). The alteration mineralization assemblages indicate the occurrence of deep potassic alteration zones and porphyry Cu-(Mo) mineralization in the Disuga area.
hydrothermal alteration / elemental mobility / zircon geochronology / porphyry deposit / Zhongdian arc / Southwest China
2025 Geological Society of China
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