湖南产于前寒武系中金矿床毒砂的标型特征  

Typomorphic characteristics of arsenopyrite in Precambrian gold deposit, Hunan

作　　者：鲍振襄[1] 万容江[1] 鲍珏敏[1] 

机构地区：[1]湘西地勘5队,湖南乾州416007

出　　处：《黄金地质》2000年第4期39-45,共7页Gold Geology

摘　　要：湖南产于前寒武系中的金矿床尤其是砷金矿床 ,毒砂分布甚广 ,毒砂中 Au含量一般 12 0×10 -6～ 2 50× 10 -6,金的分布率达 64.3%～ 93.1% ,是金的主要载体矿物。毒砂的形成有早、晚两期 ,化学成分为 S富 As亏型 ,并以富含微量元素 Sb、 ( Se)、 Ni、 Co而贫 Mn以及晶胞参数 a0 值增大等为标型特征。绝大部分含 Au毒砂的光片没有显微金存在 ,即使利用电子探针也难以发现金。由此产生了毒砂中的金以超微细颗粒存在或以晶格金形式存在的分歧。经有关金矿床多项实验研究结果 ,初步认为毒砂中的“不可见金”大多数是以纳米级微细粒状存在。In Precambrian gold deposits, especially in the As Au deposits of Hunan,ar senopyrite is widely distributed, gold contents is generally 120×10 -6 ～250×10 -6 and the rate of gold distribution is 64 3% ～ 93 1%. The arsenopyrite is the main carrier mineral of gold. The formation of arsenopyrite have early and late stages and the chemical composition is rich in S and poor in As. The arsenopyrite is typomorphically charactered by the rich trace elements, such as Sb, (Se), Ni and Co, poor Mn and the raise of unit cell parameter a 0. There isn't microgold in the most of polished sections with Au bearing arsenopyrite, even by the electron microprobe, there isn't gold yet. Therefore, it has divergence that gold occurres in arsenopyrite by ultramicro grain or lattice gold. Based on many experimental research in the relative gold deposits, it is considered that invisible gold mostly occurred in arsenopyrite by nanometer fine grain.

关 键 词：前寒武系 金矿床 毒砂 湖南 晶胞参数 存在形式 电子探针 

分 类 号：P618.51[天文地球—矿床学]