西藏班公湖—怒江成矿带中段砂金成色特征  

Fineness features of placer gold in the middle part of the Bangonghu lake to Nujiang River mineralization belt,Tibet

作　　者：卫万顺[1] 路彦明[1] 刘桂阁[1] 范俊杰[1] 陈勇敢[1] 

机构地区：[1]武警黄金地质研究所,河北廊坊065000

出　　处：《黄金地质》2001年第4期9-14,共6页Gold Geology

摘　　要：该区砂金成色具有明显的不均一性、继承性和后期改造性。成色变化范围大 (5 31 4 8～10 0 0 ) ,具有粒度越大成色越高的趋势。区内西部砂金矿床的溶蚀系数小于 1 0 3,为近原生源砂金 ;东部的 1 0 3～ 1 10 ,为中近原生源砂金 ;崩纳藏布大于 1 10 ,为远原生源砂金。自然金化学成分研究表明其原生金矿为中低温热液型金矿床。The fineness of placer gold in this district is apparently featured by inhomogeneity,inheritance and afterdeformation.The range of fineness is wide(531 48～1 000).The bigger the grain size is,the higher the fineness will be.The placer gold deposits in the western district with coefficient of solution<1 03 belong to proxial primary placer gold,those in the eastern district with coefficient of solution 1 03～1 10 belong to midium proximal primary placer gold,and the Bengnazangbu belong to distant primary placer gold because its coefficicent of solution is>1 10. Study of the chemical composition of native gold indicates that the primary gold deposits belong to mesothermal epithermal gold deposits,its possiable to find primary gold deposits in granite of later Yanshan orogenic period in the Nalanggou area.

关 键 词：原生金 成色 西藏 砂金矿床 溶蚀系数 粒度形态 

分 类 号：P618.51[天文地球—矿床学]