四川会理地区红铜山铜矿地质特征及成因分析

Geological Characteristics and Genesis Analysis of Hongtongshan Copper Deposit in Huili Area, Sichuan Province

红铜山矿区地处南北向延伸的川滇被动大陆边缘裂谷系(康滇地轴)的中段,从元古代至今,区内经历了晋宁、华力西、印支、燕山、喜山等构造运动。在会理~东川坳拉槽区域地壳收缩、挤压条件的构造背景控制下,区内层系形成了一系列的复背斜、复向斜和逆冲断裂,它们以东西向为主,南北向次之,两者叠加干涉形成本区双层结构的构造格局。下层构成下褶皱基底,发育东西向褶皱,上层构成上褶皱基底,发育南北向褶皱。许多断层是区域上的重要深大断裂。区内岩浆活动频繁、规模小、基性~超基性岩发育为特征,海西期的基性火成岩类中产生有铜矿和铁矿;出露地层主要为前震旦系会理群地层,次为中生代上三叠系地层。会理群落雪组一段为本区最重要的含铜矿层位。

Hongtongshan mining area is located in the middle of the South-North extension of the Sichuan-Yunnan passive continental margin rift system(Kangdian axis).From Proterozoic to present,the area has undergone tectonic movements such as Jinning,Hualisi,Indosinian,Yanshan and Himalayan.Controlled by the tectonic background of crustal contraction and compression conditions in Huili^Dongchuan depression,a series of complex anticlines,synclines and thrusting faults are formed in the stratigraphic system.They are mainly in the East-West direction,followed by the North-South direction.The upper layer constitutes the basement of the upper fold,and the North-South fold develops.Many faults are important deep faults in the region.The area is characterized by frequent magmatic activity,small scale and development of BASIC-ULTRABASIC rocks.Copper deposits and iron ores occur in Hercynian basic igneous rocks,and the exposed strata are mainly pre-Sinian Huili Group strata,followed by Mesozoic Upper Triassic strata.The first member of Xue Formation in Huili Community is the most important copper-bearing horizon in this area.