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沙溪斑岩铜(金)矿床位于大别隆起北部金寨—舒城火山岩带的东南缘,庐江—枞阳中生代火山岩盆地的西北缘,处于郯庐断裂带内部,是中国东部与闪长岩类有关斑岩铜(金)矿床的典型实例。其成矿岩体——石英闪长斑岩的Rb-Sr同位素等时线年龄为127.9±1.6Ma,富碱、富钠、富轻稀土和大离子亲石元素,并具较低的锶同位素初始比值(I_(Sr)=0.70580,为壳幔混源岩浆演化分异的产物。矿床的蚀变和矿化分带模式与闪长岩模式相似。成矿流体具较高的含盐度,CO_2、Ca~(2+)、Na和Cl-组分高。主成矿期包裹体均一温度变化于280～420℃,成矿流体的δ~(18)O值变化于3.51‰～5.52‰,δD值介于82.4‰～-59.8‰,硫化物的δ~(34)S值变化于-0.3‰～2.49‰,包裹体中CO_2的δ~(13)C值介于-2.66‰～-6.53‰,同位素资料显示沙溪斑岩铜(金)矿床成矿热液及成矿物质主要来自岩浆体系。
The Shaxi porphyry Cu (Au) deposit is located in the southeastern margin of the Jinzhai-Shucheng volcanic belt in the northern part of the Dabie Uplift. The northwestern margin of the Lujiang-Zongyang Mesozoic volcanic basin lies in the interior of the Tanlu fault zone, Typical examples of porphyry copper (gold) deposits. The Rb-Sr isotopic isochron age of the quartzite diorite porphyry is 127.9 ± 1.6Ma, which is rich in alkali, rich in sodium, rich in light rare earth and large ion lithophile, and has lower strontium isotope The initial ratio (I_ (Sr) = 0.70580, which is the product of differentiation of crust-mafic magmatism. The alteration and mineralization zoning pattern of the ore deposit are similar to the diorite model.The ore-forming fluid has high salinity, The contents of CO_2, Ca_2 +, Na and Cl_ are high.The homogenization temperature of the main mineralization changes from 280 ℃ to 420 ℃, and the δ 18 O values of the ore-forming fluids change from 3.51 ‰ to 5.52 ‰ , δD values ranged from 82.4 ‰ to -59.8 ‰, and the δ ~ (34) S values of sulfides varied from -0.3 ‰ to 2.49 ‰. The δ ~ (13) C values of CO_2 in the inclusions ranged from -2.66 ‰ ~ 6.53 ‰, isotope data show that the Shahe porphyry copper (gold) ore mineralization and ore-forming materials mainly from the magma system.