沃溪钨锑金多金属矿床成矿特征及深部构造与垂向矿化变化研究

Metallogenic characteristics and structure in deep part of W-Sb-Au polymetallic deposit and vertical variation of mineralization,Woxi in western Hunan

沃溪矿床产于红岩溪-唐浒坪反"S"型构造的西半部,赋存于沃溪拆离断层(F1)下盘、新元古界青白口系板溪群马底驿组层间剪切构造带内。矿化类型主要为层状(或层脉),其次为脉状-网脉状。层脉矿化主要赋存于层间断裂中,由多个含钨锑金石英脉的扁豆体组成;脉状-网脉状矿化依附于层脉,多出现在层脉的下盘,并与蚀变围岩一起,主要构成脉带含金或含钨金矿体。成矿具有独特的沿倾向发育很深、侧伏成矿和柱状富集特点。随着近年来开采深度的加大,发现深部构造和矿化有明显变化。本文在该矿床成矿特征研究的基础上,探讨了沃溪矿床深部构造与矿化富集规律以及垂向变化趋向,指出了找矿意义。

Woxi deposit occurs in the west part of the reversed S-shaped Hongyanxi-Tanghuping structure,which is located at the footwall of Woxi detachment fault(F1)and inside the interstratified shear structural belt of Madiyi Formation of Banxi Group of Neoproterozoic Qingbaikou system.The mineralization occurs mainly as stratified(or as bedded vein)with lesser veined or network mineralization.Bedded vein mineralization mainly occurs inside the interstratified fractures and is composed of a number of lenticle bodies of W-SbAu-bearing quartz vein.Veined or network mineralization is attached to and mostly occurs in the lower part of the bedded vein mineralization along with the altered wall rocks,and it forms the Au-W-bearing orebodies inside the vein belt.The mineralization develops deeply along the direction of dip and has unique characteristics such as lateral trending mineralization and columnar enrichment.With the increase of mining depth in recent years,obvious variation is discovered in the structure and mineralization in the deep part.Based on the research of the metallogenic characteristics of the deposit,the paper elaborated on the deep structure,enrichment regularity and vertical variation,and the author pointed out the significance of prospection.