甘肃加甘滩超大型金矿床矿化富集规律及控矿因素

甘肃加甘滩金矿床位于西秦岭造山带西北缘,是夏河—合作金矿带南缘新发现的具有超大型找矿潜力的金矿床。通过详细的野外地质调查及室内综合研究,分析了矿床矿化富集规律并剖析了控矿因素。研究表明:(1)由矿床厚度变化规律可知,矿区西部见矿厚度明显大于东部,表明矿体具有往西部深部延伸的趋势;(2)由品位变化规律可知,品位高值集中区主要位于矿区5#~0#线中部区域,表明该区为成矿物质沉淀集中区,矿区西部至东部品位总体体现出由高至低的演化特征,表明成矿流体可能从西部被运移至东部;(3)由总体矿化富集规律可知,矿区西部矿化强度明显大于东部,中部虽然存在着一低洼地带,但可能是存在构造破矿的原因。通过对矿床控矿因素的解析,认为地层、构造及蚀变作用等因素与矿床的形成密不可分,其中,构造为主要控矿因素。结合矿床矿化富集规律、控矿因素及矿区最新钻探施工成果,进一步分析认为矿区西部深部及其外围具有较大的找矿潜力,下一步探矿工作应围绕矿区西部深部或北西部外围进行。

Mineralization Enrichment Regularity and Controlling Factors of Jiagantan Super-large Gold Deposit in Gansu Province

The Jiagantan gold deposit in Gansu Province is located in the western part of the Qinling orogenic belt,which is a newly discovered gold deposit with super-large prospecting potential in the southern part of Xiahe-Hezuo gold mineralized belt.Taking the Jiagantan super-large gold deposit as the study example,based on the detailed field geological investigation and comprehensive study results,the mineralization enrichment regularity and ore-controlling factors of the deposit are analyzed.The study results show that:①the thickness variation regularity of the deposit show that the ore-bodies thickness of the western part is obviously larger than that of the eastern part of the mining area;②the elements distribution contours indicated that the concentration regions of high grade value are mainly distributed in the area of 3# ～ 0# exploration line,which is the precipitation concentration area of the metallogenic materials in the mining area;from the west to the east of mining area,the overall grade reflects the evolution characteristics from high to low,which indicated that the metallogenic materials is migrated from the west to the east of mining area;③the overall mineralization enrichement regularity show that the mineralization intensity of the west is greater than the one of the east of the mining area,the existing of low-lying in the central mining area,it is resulted by the ore-bodies are destructed by the existence of faults.Through the analysis of the ore-controlling factors,the results show that the factors of formation,structure and alteration are closely related to the formation of the gold deposit in the mining area,among them,structure is the most important one of the ore-controlling factors.Combing with the analysis of mineralization regularity and ore-controlling factors of the deposit and the newly drilling results of the mining area,the further discussion results show that prospecting potential of the depth of the western part and its periphery of the mining area are huge,and the further prospecting work should be focused on these areas.