贵州泥堡大型金矿床金的三维富集规律及成矿模式探讨

Study on three-dimensional gold enrichment regularity and metallogenic model of Nibao large-scale gold deposit,southwestern Guizhou

泥堡金矿床是黔西南近些年发现的大型金矿床之一,前人对金的富集规律及成矿过程开展了大量的研究,但从金的三维富集规律方面探讨金的成矿模式尚未研究。本文利用3Dmine软件对泥堡金矿床的地层、断层和矿体进行三维可视化地质建模。结果显示,矿体呈顺层状和沿断层产状产出,Au主要富集层位为上二叠统龙潭组二段和一段(P3l2、P3l1),赋存位置为构造蚀变体(Sbt)、F1断层内、F1断层两侧、背斜轴面附近、背斜轴面与断层F1之间,背斜轴面倾向一侧的背斜翼部,且Au含量具有斑块状分布和带状连续分布特点,表现出Au在局部斑块处含量高,并向四周持续递减。据此,本文结合Au的物质来源、流体来源、以及矿床中的地层岩性、断层和背斜组合等特征,获取了矿床形成的流体流向路径,提出了"S型"和"断层+背斜轴面"的成矿模式,这对于泥堡金矿床及类似的矿床开展下一步找矿和成矿预测具有一定的参考意义。

Objectives:The Nibao gold deposit is one of the large gold deposits discovered in recent years in southwestern Guizhou.Previous studies mainly focus on the gold enrichment regularity and metallogenic process.However,the gold metallogenic model from the perspective of the three-dimensional gold enrichment regularity has not been studied.Methods:In this paper,a 3Dmine software was utilized to model the strata,faults and ore bodies of the Nibao gold deposit in three-dimensional visualization.Results:Results show that the ore body is stratified or occurs along the fault occurrence.Au mineralization mainly occurs in the strata of the 2nd and 1st Member of the Upper Permian Longtan Formation (P3l1and P3l2),and is controlled by the tectonic alteration body (Sbt),fault F1,and the Erlongqiubao anticline.In addition,Au mineralization exhibits characteristics of patchy distribution and continuous band-shaped distribution,showing that Au content is high in local patches and decreases to the surrounding areas.Conclusions:Based on the ore-forming material source,ore fluid source,and characteristics of stratum lithology,faults and anticline,the fluid flow path formed by the deposit is obtained.The"S-type"and"fault+anticline axis"metallogenic models are proposed,which has reference significance for further metallogenic prediction of the Nibao gold deposit and similar deposits.