新疆拜城县察尔其铜矿床的沉积环境及成矿作用分析

察尔其铜矿位于新疆拜城县,是区域滴水铜矿带的东段。铜矿体产于新生界中新统-上新统康村组第四段(N_(1-2)k~4)的第3亚段和第5亚段;铜矿化主要产于杂色砂岩及其与泥灰岩接触部位附近。矿区含矿层主要有B矿层和C矿层,B矿层划分出3条铜矿体,其中B1、B2号矿体为主矿体;C矿层矿体划分出5个矿体,其中C1号矿体为主矿体,也是察尔其铜矿区的主矿体。矿区新近系康村组含矿层沉积特征为扇三角洲前缘亚相的水下分流河道微相和分流间湾微相,滨浅湖亚相的浅湖砂坝微相和浅湖泥微相,局部出现深湖相。康村组沉积物来自再旋回造山带物源区,含矿砂岩的碎屑来自灰岩、泥灰岩、砂岩、泥岩、变质岩、深成岩、火山岩等,与北邻天山造山带的岩性相当。认为察尔其铜矿床属于与新近纪湖相沉积作用有关的砂岩型铜矿,并将铜矿形成过程分为2个成矿期3个成矿阶段,建立了矿床成矿模式。

Sedimentary metallogenic environment and mineralization of Qarqi copper deposit in Baicheng county, Xinjiang

Qarqi copper deposit occurs at the east part of the regional Dishuidong copper ore belt in Baicheng county, Xinjiang with ore bodies locating in the third and fifth sub-member of the (Miocene-Pliocene)fourth member of Kangcun formation of Cenozoic Erathem and mineralization at the contact of mottled sandstone and marl. There are two ore-bearing layers B and C. In the layer B are located three ore bodies of which B1 and B2 are the main ones; in the layer C, five ore bodies, C1 the main one of the layer and the whole Qarqi copper deposit. The Neogene Kangcun formation is characterized by sub-water flow channel micro-facies and the inter-flow channel bay micro-facies of the front sub-facies of sedimentary fan delta and bar micro-facies and shallow mud micro-facies of shore-shallow lake sub-facies and local deep lake facies. Sediments of Kangcun formation are derived from the recycled orogenic belt; detritus of the ore-bearing sandstone from lime stone, marl, mudstone, metamorphic rock, plutonic rock, volcanic rock etc. which are correspondent to those of neighboring Tianshan orogenic belt to the north. Qarqi copper deposit is a sandstone type Cu deposit related to Neogene lake facies sedimentation. And is formed in two metallogenic epochs and three stages based on which metallogenic model of the deposit is built.