湖南水口山矿田金矿控矿因素、成矿演化及成矿预测

Ore-controlling factors,mineralization evolution and prediction of Shuikoushan Au deposit,Hunan Province

水口山矿田是一大型金多金属矿田,其金资源储量达90 t。通过系统总结各金矿床地质特征,初步厘定金矿化期次,进而分析控矿因素,对成矿演化进行探讨,建立成矿模型,进行成矿预测。研究表明,区内金矿化与地层、倒转褶皱、断裂、花岗岩体关系密切。其中地层控矿主要表现为成矿层位赋存于当冲组、栖霞组层间破碎带或与岩体接触带中;构造控矿主要表现为背斜虚脱空间、层间破碎带、断裂带等是矿化富集的有利部位;岩浆岩控矿表现除岩体接触带控矿外,还有不同成因类型金矿围绕岩体呈分带现象,围绕岩体由地表到深部表现为氧化淋滤型独立型金矿—接触破碎独立型金矿—浅成低温热液独立型金矿—远距离热液充填交代伴生型金矿—接触交代伴生型金矿。金矿石沉淀与来自岩浆热液的成矿流体及大气降水引发的水岩反应、混合作用、沸腾作用有关,是成矿的主要3种机制。

The shuikoushan deposit is a large gold-polymetallic ore field with gold reserves of 90 tons.By systematically summarizing the geological characteristics of each gold deposit,the gold mineralization period is preliminarily determined.Based on analyzing ore-controlling factors,discussing the metallogenic evolution and establishing the metallogenic model,the metallogenic prediction was carried out.Studies have shown that gold mineralization in the area is closely related to strata,inverted folds,faults,and granite bodies.The ore-controlling strata are mainly characterized by the occurrence of ore-forming strata in the interlayer fracture zone of Dangchong Formation and Qixia Formation or in the contact zone with the rock mass.Structural ore control is mainly manifested as anticline detachment space,interlayer fracture zone,fault zone and so on,which are favorable sites for mineralization enrichment.In addition to the ore-controlling performance of the contact zone of the rock mass,there are different genetic types of gold deposits around the rock mass.From the surface to the deep part of the rock mass,there are independent gold deposits of oxidation leaching type-independent gold deposits of contact crushing-epithermal low-independent gold deposits of temperature hydrothermal-associated gold deposits of long distance hydrothermal filling metasomatic-associated gold deposits of contact metasomatic.The precipitation of gold ore is related to the water-rock reaction,mixing and boiling caused by magmatic hydrothermal ore-forming fluid and atmospheric precipitation,which are the three main mechanisms of mineralization.