甘肃公婆泉斑岩型铜矿床地球化学特征及找矿模式

Geochemical features and prospecting model of Geongpoquan porphyry-type copper deposit in Gansu

公婆泉斑岩铜矿产于次英安斑岩和花岗斑岩体中。通过对火山岩岩系、岩浆岩、断裂构造、矿体和蚀变围岩等方面的地球化学特征的研究 ,发现围岩蚀变与斑岩型铜矿床具有相似的蚀变特征 ,它们在地球化学特征上表现为“一盖一帽一空心”的特征 ,即“盖”是指斑岩体上方覆盖的火山岩系中形成的V ,Ti,Cr,Ni元素异常 ;“一帽”是指斑岩体上方及内外接触带的B ,As等异常 ;“一空心”是指Cu ,Au ,Ag ,Pb ,Zn ,Mo ,Ba在斑岩体上方或浅部异常中心形成负异常。该特征可判别矿床的剥蚀程度。

Gongpoquan porphyry-type copper deposit is existed in secondary dacite-porphyry and granite-porphyry bodies. After researching geochemical characteristics of volcanic rock series, magmatic rocks,faulted structure,ore bodies, wall-rock alteration,the authors point out that wall-rock alteration of the ore bodies has the same alteration features as those of porphyry-type copper deposit.That is to say,there“one cover,one cap,one hollow heart ”peculiarity of geochemical characteristics.The features can be applied to estimating the denudation degree of the ore deposit.