Petrogenesis and Physicochemical Conditions of Fertile Porphyry in Non-arc Porphyry Mineralization:A Case from Habo Porphyry Cu-Mo Deposits,SW China  

作　　者：ZHANG Aiping ZHENG Yuanchuan SHEN Yang Qi Qunjia WANG Zixuan WU Changda WANG Lu 

机构地区：[1]School of Earth Sciences,Yunnan University,Kunming 650500,China [2]Yunnan Key Laboratory of Sanjiang Metallogeny and Resources Exploration and Utilization,Kunming 650500,China [3]School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China [4]State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China

出　　处：《Acta Geologica Sinica(English Edition)》2023年第2期469-485,共17页地质学报（英文版）

基　　金：supported by grants from the National Key Research and Development Program of China(Grant Nos.2016YFC0600310 and 2019YFA0708602);the National Natural Science Foundation of China(Grant Nos.41702091,41872083 and 42022014);the Yunnan Applied Basic Research Project(Grant No.202101AT070073);the China Fundamental Research Funds for the Central Universities(Grant No.2652018133);the Scientific Research Fund of the Yunnan Provincial Education Department(Grant No.2022Y016)。

摘　　要：The Habo deposit is a typical porphyry Cu-Mo deposit in the Ailaoshan–Red River metallogenic belt.Ore minerals in the Habo deposit typically occur as veins in the monzonite porphyry.Zircon U-Pb dating suggests that the monzonite porphyry formed at 35.07±0.38 Ma.The monzonite porphyry is characterized by high SiO_(2),Al_(2)O_(3),K_(2)O and Na_(2)O contents,with A/CNK ratios ranging from 0.97 to 1.02.All samples exhibit fractionated REE patterns,characterized by high(La/Yb)N ratios(9.4–13.6,average of 11.2).They show adakite-like geochemical features,high Sr concentrations(627–751 ppm,average of 700 ppm),low Y concentrations(15.13–16.86 ppm,average of 15.81 ppm)and high Sr/Y values(39.5–47.4,average of 44.3).These samples have high initial^(87)Sr/^(86)Sr ratios(0.7074–0.7076)and negativeεNd(t)values(-5.1 to-3.7),whereas the zirconεHf(t)values range from-2.2 to+0.4,suggesting that the monzonite porphyry was derived from the partial melting of a thickened juvenile lower crust.The oxygen fugacity,calculated on the basis of the chemical composition of the amphiboles,shows?NNO values ranging from+1.65 to+2.16(average of 1.94)and lg(fO_(2))ranging from-12.72 to-11.99(average of-12.25),indicating that the monzonite porphyry has high oxygen fugacity.Zircons have high Ce^(4+)/Ce^(3+)ratios(29.29–164.24,average of 84.92),with high?FMQ values ranging from+0.50 to+1.51(average of 0.87)and high lg(fO_(2))values ranging from-14.72 to-12.85(average of-14.07),which also indicates that the oxygen fugacity of the magma was high.The dissolved water content of the Habo monzonite porphyry is 9.5–11.5 wt%,according to the geochemical characteristics,zircon-saturation thermometry(692–794°C)and the mineral phases(amphibole,no plagioclase)in the deep magma chamber.Combined with previous studies,we propose that the high oxygen fugacity and high water content of magma played key roles in controlling the formation of the Habo and other Cu-Mo-Au deposits in the Ailaoshan–Red River metallogenic belt.

关 键 词：magmatic oxidation state water content monzonite porphyry Habo porphyry Cu-Mo deposit Ailaoshan-Red River metallogenic belt 

分 类 号：P618.41[天文地球—矿床学] P618.65[天文地球—地质学]