云南潞西上芒岗红色粘土型金矿地质特征

GEOLOGICAL CHARACTERISTICS OF THE SHANGMANGGANG RED\|CLAY\|TYPE GOLD DEPOSIT IN LUXI, YUNNAN

潞西上芒岗红色粘土型金矿赋存于下二叠统岩溶面之上的第三、第四系红色粘土层中 ,矿体形态受地形控制明显 ,呈似层状。品位较高 ,规模中等 ,适合于露天开采。矿体的红土化作用不彻底 ,去硅富铁铝能力低 ,常见高岭石与伊利石共生。矿石中石英、褐铁矿、粘土矿物为主要载金矿物。成矿物质来自燕山中晚期形成的中侏罗勐嘎组中段与二叠系的沙子坡组的断层接触破碎带内的卡林型金矿。在湿热条件下 ,金发生活化、迁移、富集 ,在潜水面附近成矿。

The Shangmanggang red\|clay\|type gold deposit occurs in the Tertiary\|Quaternary red\|clay layers on the karst denudation of Lower Permian series. Its orebody is obviously controlled by topography. The gold grade is quite high. Lateritization of the orebody is not complete and its ability of leaching Si and concentrating Fe, Al is very low. Commonly kaolinite intergrows with illite in red\|clay layers. Au is chiefly contained in quartz, limonite and clay minerals. Mineralizing materials came from the Carlin\|type gold deposits that formed in the fault\|contact fragmental zone between the Lower Permian Shazipo Formation and the Middle Jurassic Mengga Formation during Late Yanshanian. Owing to a humid and hot climate, Au was remobilized, migrated to the vicinity of the water table and enriched in the middle to lower parts of the profile by reprecipitation.\;