青海省都兰县丘吉东沟银铅矿地质特征及找矿标志

Geological Characteristics and Prospecting Indicators of Silver lead Deposit in Qiujidonggou in Dulan County in Qinghai Province

青海省都兰县丘吉东沟银铅矿位于昆中断裂带内,区内断裂构造十分发育,主要为NW向断裂,与区域构造方向基本一致。区内含矿蚀变带与NW向深大断裂关系密切,NW向断裂为区内的主要的导矿、控矿构造,次级构造或构造膨胀部位及构造拐弯处,均为找矿的有利地段,可作为容矿场所。区内华力西期岩浆活动强烈,该期活动为区内岩浆活动的最高潮,是主要成矿期。研究区圈定2个矿带9条银铅矿体,呈脉状或透镜状赋存于蚀变硅质白云岩之NW向构造破碎带F_(8),F_(9)内,是以银为主的多金属矿体。其中I-5矿体为主矿体,平均厚度2.38m,银平均品位216.87×10^(-6),铅平均品位1.98%,主要矿化蚀变为方铅矿化、黄铁矿化、黄钾铁钒化等。本文分析了丘吉东沟银铅矿地质背景、矿床地质特征等,总结了找矿标志,预测了找矿方向,以期为类似地区的银铅找矿工作提供借鉴经验。

Qiujidonggou silverlead mining area in Dulan county in Qinghai province is located in Kunzhong fault zone.The fault structures in the area are very developed with the main trend of NW.They are basically consistent with regional structural direction.The ore alteration zone in the area is closely related to the mineralization of deep faults with the trend of NW.The faults with the trend of NW are main ore guiding and controlling structures in the area.Its secondary structures or structural expansion position and structural turning point are favorable areas for ore prospecting,which can be used as ore hosting sites.The Variscan magmatic activity is strong in this area,which is the climax of magmatic activity and the main metallogenic period in this area.Two ore belts and nine silver lead ore bodies are delineated in the study area.They are vein or lens like and occur in structural fracture zone F_(8) and F_(9) of altered siliceous dolomite with the trend of NW.They are polymetallic ore bodies dominated by silver.Ⅰ-5 ore body is the main ore body in the area,with an average thickness of 2.38m,average silver grade of 216.87×10^(-6),and average grade of lead 1.98%.Main mineralization alteration is galena mineralization,pyritization and vanadization of yellow potassium iron.In this paper,geological background,ore body geological characteristics,ore quality,ore type and wall rock alteration of qiujidonggou silver lead deposit have been analyzed,prospecting indicators have been summarized,and prospecting direction has been predicated.It will provide some references for the silverlead prospecting work in similar areas,and has guiding significances for the further exploration in deep and surrounding areas of Qiujidonggou silverlead deposit.