青海柳弯区铅锌铜多金属矿床地质特征及控矿条件

Geological Characteristics and Ore-controlling Conditions of the Liuwanqu Pb-Zn-Cu Polymetallic Deposit in Qinghai Province

柳弯区铅锌铜多金属矿床是北祁连地区较为重要的VMS型矿床之一。由于本区地质背景复杂,矿体受后期构造改造严重,矿体分布规律难以掌握,一直未能取得找矿突破。笔者结合最新勘查成果,对矿区地质、矿床地质特征进了分析,总结了矿区矿化带特征、矿体特征、矿石组构特征、矿物成分及伴生关系、围岩蚀变特征等;对本区矿床控矿条件进行了讨论,并和国内外典型矿床进行了对比分析。本区成矿明显受地层、构造及变质作用等因素的影响。在柳弯区35线以西,矿体主要控制高程为3 000～3 500m;而柳弯区35线以东,矿体主要控制高程为2 700～3 000m。矿体向深部仍未圈闭,深部找矿潜力较大。

The Liuwanqu deposit is one of the most important VMS-type deposits in North Qilian area.However,due to the complexity of the geological background in this region,the ore body has been reformed seriously by the later structure,the distribution rule of the ore body is difficult to grasp,and the prospecting breakthrough has not been achieved.In this paper,combined with the latest exploration results,the geology of mining area and deposit have been analyzed,and the characteristics of mineralization zone,orebody,ore fabric,mineral composition and associated relationship,the alteration of surrounding rock and so on have been sμmmarized.The ore-controlling conditions of the ore deposits in this area have been discussed,which have been compared with typical ore deposits at home and abroad.The ore-forming in this area is obviously influenced by stratigraphic,structural and metamorphic factors.The distribution of ore bodies has a certain regularity.In the west of the 35 line of the Liuwanqu deposit,the mainly control heights of the ore body are 3000~3500 m,while the ones in the east are 2700~3 00 m.The ore body is not yet trapped to the deep part,which has large potential of deep prospecting.