西藏昌都地区错纳Pb-Zn-Ag矿床地质特征及成矿条件分析

Geological features and metallogenic conditions of Cuona Pb-Zn-Ag deposit at Changdu area in Tibet

错纳Pb-Zn-Ag矿床是三江成矿带中段昌都地区典型的赋存于沉积岩的中型铅锌矿床。在野外调查错纳矿床成矿地质背景、矿床地质特征的基础之上,对含矿地层、控矿构造、矿体特征、矿石组构、成矿期次进行了系统研究,对其成矿条件进行了深入分析。研究结果表明,澜沧江逆冲推覆系统是该区主要的控矿构造,矿体主要赋存在逆冲推覆构造产生的次级逆断层的张性裂隙及构造破碎带中。上三叠统阿堵拉组第一岩性段石英砂岩、粉砂岩是最有利的含矿岩性。该矿床为受岩性和断裂共同控制的热液矿床。

Cuona Pb-Zn-Ag deposit is located in the middle of the Sanjiang polymetallic metallogenic belt,which is a representative sediment-hosted Pb-Zn deposit at Changdu area.Based on field survey of geological settings and deposit geology,systematically researches on ore bearing strata,ore forming-structure,orebody features,ore textures and mineralization stages were carried out.Furthermore,metallogenic conditions of the Cuona deposit were analyzed.The result shows that the Lancangjiang thrusting tectonic system is the major ore-controlling structure for the formation of this deposit.The ore bodies occur in tensile fractures or structure fracture zones of secondary thrust fault.The first lithologic section of the Upper Triassic Adula formation is the favorable ore-bearing lithology.Cuona deposit is a hydrothermal ore deposit controlled by lithology and fault.