甘肃合作早子沟金矿床品位变化规律及特征探讨

早子沟金矿床是近年来在西秦岭地区发现的又一特大型金矿床。文章通过对该矿区矿体的矿化强度指数、品位变化规律的统计计算,建立了矿体金品位变异函数模型,分析研究了矿体金品位分形分布特征及矿体金金属量-平均品位特征。金品位变化规律及特征的研究表明,金矿体在深部向北东侧伏,金矿体品位呈波状变化,矿体金品位的对数转换分布基本服从正态分布,变异函数模型显示具有各向异性,北东55°方向为矿化最连续方向;金品位分形结构特征研究表明,对矿区资源储量贡献最大的矿石类型是石英细脉-网脉脉岩型矿石,脉岩与地层的内、外接触带及部分含矿小岩脉应是今后勘查的重点,沿倾向金品位具有明显的等间距变化特征,向北东方向每隔140~260 m将会出现富矿段。基于以上认识,结合矿体产出的空间位置、控矿构造条件,探讨了矿床深部找矿方向,总结了今后的勘查重点部位及重要的岩性组合。

Grade variation regularity and characteristics of Zaozigou gold deposit in Hezuo Town, Gansu Province

The Zaozigou gold deposit is another superlarge gold deposit discovered recently in West Qinling region, and lots of researchers have conducted fairly detailed study. Based on statistics of mineralization intensity indices and grade variation regularities, the authors established the gold grade variation function model of the orebody, analyzed gold grade fractal distribution characteristics of the orebody and gold metallic quantity-average grade features of the orebody. The study of the variation regularity and features of gold grade shows that the gold orebody pitches northeastward in the depth, the grade of gold orebody exhibits wavy variation, the gold grade logarithmic transformation of the orebody basically obeys normal distribution, the variation function model exhibits anisotropy, and the most continuous mineralization is in the NE 55° direction. The study of fractal structural characteristics of gold grade shows that the quartz veinlet-stockwork dike type ores make the largest contribution to the resource reserves in the ore district, the dike rocks, the inner- and exo-contact zone between dike rocks and strata and some ore-bearing small veins deserve particular attention in future exploration, the gold grade exhibits obvious equi-distant variation in dipping direction, and rich ore blocks are likely to appear every 140~260 m. On such a basis and in combination with spatial position of the orebody and ore-controlling structural conditions, this paper deals with the deep ore-prospecting targets, sums up the key positions and important lithologic assemblages for the further exploration work in the ore district.