甘肃北山奇石岭钨矿床地质特征及找矿标志

甘肃北山奇石岭钨矿床大地构造部位处于敦煌地块之敦煌基底杂岩隆起和柳园裂谷结合部位,钨矿体产出于华里西晚期石英闪长岩与长城系铅炉子沟群内接触带中,成因类型为与中酸性岩浆岩有关的中高温热液矿床,接触带构造为直接的控矿构造。结合区域地质背景和矿床地质特征,初步认为该地区与中酸性岩浆岩有关的钨矿床的找矿标志为:规模较小的华力西晚期中酸性岩浆岩、钨地球化学异常、钨重砂异常、岩体内接触带、岩石蚀变标志(硅化、磁铁矿化、赤铁矿化、褐铁矿化及阳起石化、绿帘石化、绿泥石化、绢云母化)。对该矿床成矿地质特征和找矿标志的研究对于推动甘肃北山地区钨的找矿工作具有积极意义。

Geological characteristics and prospecting sign of Qishiling tungsten deposit in Beishan, Gansu Province

Tungsten deposits have been discovered in late Variscan quartz diorite located in the junction of Dunhuang basement complex uplift and Liuyuan rift. Tungsten ore bodies occur in the contact zone between late Variscan quartz diorite and the Qianluzigou group. The genetic type of tungsten ore bodies is a medium-high temperature hydrothermal deposit related to intermediate-acid magmatic rocks in late Variscan. The contact zone structure is a direct ore-controlling structure. Combined with the regional geological background and geological characteristics of the deposit, it is preliminarily considered that the prospecting criteria of tungsten deposits related to intermediate-acid magmatic rocks in the area are small-scale intermediate-acid magmatic rocks in late Variscan, tungsten geochemical anomalies, tungsten heavy sand anomalies, contact zones within the rock mass, rock alteration markers(silicification, magnetite, hematite-limonite mineralization and actinolite, epidote-chloritization, sericitization) and direct prospecting clues. The study of metallogenic geological characteristics and prospecting indicators of the deposit has positive significance for promoting the prospecting of tungsten deposits in Beishan area of Gansu Province.