The relationship between Cu-Mo-Au mineralization in Machangqing ore deposit is significant to understanding the process of ore-forming and geological exploration. 40Ar/39Ar isotopic dating method is performed on two hydrothermal muscovite samples collected from skarn-type Cu-Mo-Au ore in Luandongshan segment and altered-rock-type Au ore in Rentouqing segment. Muscovite from the skarn-type (B119) ore yields the plateau age of 35. 25 ±0. 36 Ma,the normal isochron age of 35. 0 ± 1. 8 Ma and the inverse isochron age of 34. 8 ± 1. 9 Ma; Muscovite from altered-rock-type ore (B118) yields the plateau age of 35. 35 ±0. 32 Ma,the normal isochron age of 34. 44 ±0. 99 Ma and the inverse isochron age of 34. 4 ± 1. 2 Ma. These ages are consistent with the syenite age (35. 6 ± 0. 3 Ma) , granitic porphyry age (35. 0 ± 0. 2 Ma) and the age of Cu-Mo mineralization (35. 8 ± 1. 6 Ma) , which indicates that the Machangqing Cu-Mo-Au deposit has link with the magmatic combination of syenite porphyry + monozonite porphyry + granitic porphyry + porphyritic granite and that Cu-Mo-Au mineralization is the product of the identical structural-magmatic- metallogenic system.%马厂箐矿集区铜、钼、金矿化之间的关系对于认识该矿床的成矿作用过程及地质勘查具有重要意义.利用40 Ar-39 Ar同位素定年方法对乱硐山矿段夕卡岩型铜钼金矿化和人头箐矿段蚀变岩型金矿石中热液白云母进行同位素定年,得到夕卡岩化矿石中白云母样品( B119)40 Ar-39 Ar坪年龄为35.25±0.36 Ma,等时线年龄为35.0±1.8 Ma,反等时线年龄为34.8±1.9 Ma.蚀变岩型金矿化矿石中白云母样品(B118)40 Ar-39 Ar坪年龄为35.35±0.32 Ma,等时线年龄为34.44±0.99Ma,反等时线年龄为34.4±1.2 Ma.这与正长斑岩(35.6±0.3 Ma)、花岗斑岩(35.0 ±0.2 Ma)、斑岩型铜钼矿化成矿年龄(35.8 ±1.6 Ma)和(33.9土1.1 Ma)较为一致,显示马厂箐铜钼金矿床与正长(斑)岩+二长(斑)岩+花岗斑岩+斑状花岗岩岩性组合有关,铜钼金成矿属于同一个构造—岩浆—成矿系统的产物.
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