阿尔金北缘索尔库里北山铜银矿床控矿构造分析

索尔库里北山铜银矿床位于阿尔金北缘的索尔库里走廊北侧,属于受推覆构造上盘次级断裂控制的热液型矿床。矿区出露蓟县系金雁山组厚层灰岩段、中层灰岩段和青白口系小泉达坂组薄层片岩段3个岩性段。薄层片岩段所构成的推覆构造原地系统中的紧闭褶皱及面理置换、厚层灰岩段和中层灰岩段构成的推覆构造外来系统中的中等-开阔型褶皱、推覆构造以及晚期陡倾角走滑断裂构成矿区基本构造格架。推覆构造自南向北推覆并被后期阿尔金走滑断裂穿切,推覆构造面转折处上盘发育的次级断裂是主要的赋矿构造;矿化带和矿体的形态、产状、分布和规模均严格受赋矿构造的控制。 

ANALYSIS OF ORE-CONTROLLING STRUCTURE OF THE XORKOL BEISHAN Cu-Ag DEPOSIT IN THE NORTHERN ALTUN MARGINAL AREA,NORTHWESTERN CHINA

The Xorkol Beishan Cu-Ag deposit,located at the norther n side of the Xorkol Corridor at the northern margin of the Altun(Altyn Tagh)Mou ntains,is a hydrothermal deposit controlled by second-order faults in the thrus t block of nappe structure.There outcrop the thich-bedded lime stone member and medium-bedded limestone member of the Jinyanshan Formation of the Jixianian System and the thin-bedded schist member of the Xiaoquandaban For mation of the Qingbaikouan System in the ore district.The closed folds and folia tion substitution in the autochthonous block of nappe structure formed by the th in-bedded schist member,the intermediate,open folds in the allochthonous block formed by the thick-bedded limestone member and medium-bedded limestone member ,nappe structure and late-stage steep-angle strike-slip fault make up the bas ic structural framework of the ore district.The nappe is overthrust from south t o north and cut by the late-stage Altum strike-slip fault.The secondary faults developed in the thrust block at the inflection point of the nappe structural p lane are the principal ore-hosting structure.The shape,attitude,distribution a nd size of the mineralization zone and orebodies are strictly controlled by ore-hosting structure.