Cenozoic high-K alkaline magmatism and associated Cu-Mo-Au mineralization in the Jinping-Fan Si Pan region, southeastern Ailao Shan-Red River shear zone, southwestern China-northwestern Vietnam

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• 作者：My Dung Tran ; Junlai Liu ; Quang Luat Nguyen ; Yue Chen ; Yuan Tang ; Zhijie Song ; Zhaochong Zhang ; Zhidan Zhao
• 关键词：Jinping&ndash ; Fan Si Pan ; Cenozoic high potassic alkaline magmatism ; Ailao Shan&ndash ; Red River shear zone ; Porphyry deposit ; Epithermal deposit
• 刊名：Journal of Asian Earth Sciences
• 出版年：5 January, 2014
• 年：2014
• 卷：79
• 期：Complete
• 页码：858-872
• 全文大小：4768 K

文摘

The Jinping-Fan Si Pan (JFP) Cenozoic magmatic and Cu-Mo-Au metallogenic belt in the southeastern part of the Ailao Shan shear zone host the Tongchang, Chang鈥瞐n, Habo, and Chinh Sang Cu-Mo-Au deposits. These deposits form an integrated epithermal-porphyry regional mineralization system associated with 40-32 Ma high-K alkaline magmatism. The magmatic rocks in the belt have relatively low TiO₂ (<0.73 wt%), P₂O₅ (<0.29 wt%), and FeO^* (<4.99 wt%), and high Na₂O (2.86-4.75 wt%) and K₂O (4.01-7.98 wt%). They also have high contents of incompatible trace elements, and are enriched in LILE (Rb, Ba, K, Sr) and LREE. They have marked Nb, Ta, Ti and P depletion in primitive mantle-normalized spidergrams, and plot close to the EMII mantle field in the Sr-Nd isotopic diagram. These characteristics are similar to those of the Eocene high-K alkaline rocks along the northern Ailao Shan belt, eastern Tibet plateau. The sulfur and lead isotope analyses of sulfide minerals from both the ores and related magmatic rocks confirm the involvement of a magmatic ore fluid. The Cenozoic alkaline intrusions and Cu-Mo-Au mineralization in the JFP were formed prior to the initiation of left-lateral shearing along the Ailao Shan shear zone. The magmas appear to have been derived from enriched mantle, possibly with mixing of materials from the buried Tethyan oceanic lithosphere, and/or crust.