半边山含金斑岩体的发现及其地质意义

半边山含金斑岩体产于桃江花岗闪长岩体外接触带之中元古界冷家溪群中，呈北北东向带状分布。金矿化主要富集于斑岩体内的石英脉、接触破碎带及蚀变带中。在富集地段金矿化断续长约150-250m，含Au1.5×10^-6-6.67×10^-6，厚度0.47-1.65m。据人工重砂资料，金为细粒自然金。该金矿的发现不仅为湖南增加了金矿新类型的可能性，而且还提供了湘西雪峰隆起区钨锑金矿带与岩浆岩之关系的新证据。

DISCOVERY OF GOLD-BEARING PORPHYRY BODIES IN BANBIANSHAN DISTRICT AND ITS GEOLOGICAL SIGNTFICANCE

Banbianshan gold-bearing porphyry bodies are discovered in the middle proterozoic Lengji-axi group in the exocontract of granodiorite, and comprise nine bodies trending NNB. Gold mineralization is concentrated mainly in quartz veins, contact fracture zone and alteration zones in the porphyry bodies. The gold mineralization of enrichment is intermittently ex-tending about 150-250m long and 0. 47-1. 56m whick with a Au content of 1. 5×10-6-1. 67×10-6 Artificial heavy concentrate shows that the gold is represented by fine grain of native gold. This discovery gives not only the possibility to increasea new type of gold deposit in Hunan, but also new evidence of the relation between W-Sb-Au belt magmatic rocks in Xuefensr uplift of western Hunan.