里伍铜锌矿床地质特征与成因浅析  

GEOLOGICAL CHARACTERISTICS AND GENESIS OF THE LIWU Cu-Zn DEPOSIT

作　　者：陈健[1] 张增民 冯孝良[1,3] 

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]陕西省地矿局第一地质队,陕西安康725000 [3]成都地质矿产研究所,四川成都610082

出　　处：《矿物岩石》2012年第3期34-39,共6页Mineralogy and Petrology

基　　金：国家危机矿山项目(200851022)

摘　　要：里伍铜锌矿床位于四川省甘孜州九龙县,处于康滇地轴西侧,松潘-甘孜造山带东南缘,北东向木里-锦屏弧形推覆构造带北西侧后缘;为一中型富铜锌多金属矿床,矿体出露于前震旦系里伍岩群(Pt2l)变质杂岩穹隆体中。里伍、黑牛洞-大水沟、柏香林、挖金沟、中咀及笋叶林等矿段矿体呈似层状、透镜状产出,矿体边界受里伍岩群滑脱构造和S3面里控制。分析结果显示,含矿石英中包裹体的氢、氧同位素δ18 O值为-8.79‰～13.93‰,平均为0.58‰,变化范围为22.72‰;δD的值为-64.10‰～-98.30‰,平均为-59.64‰,变化范围为34.20‰。具有稳定的岩浆水、变质水特征;而包裹体成分中富Na+、Ca2++Mg2+、贫K+,富Cl-、贫F-与SO42-,富CO2气体的特征,表明成矿热液具有来源于深部热卤水及海水等的多源特征;测得成矿期蚀变黑云母40 Ar/39 Ar同位素年龄值为135.52Ma±0.82Ma,与江浪穹隆似斑状黑云母花岗岩侵入体的K-Ar同位素年龄(131Ma±5Ma)及锦屏推覆体剪切带云母K-Ar同位素年龄(129 Ma～120 Ma)接近,表明主成矿作用与区域构造-岩浆热事件同期。综合分析认为里伍铜锌矿床为海相沉积-变质硫化矿床,矿床成矿物质具多源性,成矿过程具多期次,矿床受地层构造控制明显,矿源层叠加多次岩浆-构造作用而成矿,燕山中晚期为区域重要的成矿阶段。The Liwu Cu-Zn deposit is a typical medium-sized polymetallic deposit in Sichuan Province Ganzi Jiulong County , which located in the west of Kangdian Earthls axis, the south edge of Songpan-Granze orogen and the northwest of Muli-Jinping arc thrust tectonic zone. Ore deposit exposed to preSinian Liwu group metamorphic rock dome tectonic. Ore-bodies are lenti-form or stratiform occurring in the ore block of Liwu, Heiniudong-Dashuigou, Boxiangping, Wa-jingou,Zhongju and Shunyelin. Orebody boundary is controled by Liwu rock group decollement structures and S3 surface. Analysis showed that the value of hydrogen, oxygen isotope δ^18 O in bearing quartz is -8.79‰-13.93‰ and mean is 0. 58‰. Changes in the range of 22.72‰. the value of δD is -64.10‰-98.30‰ and mean is -59.64‰, Changes in the range of 34.20‰. These data suggest that bearing quartz contains stable magmatic water and metamorphic water. The composition of the inclusions is rich of Na^＋ ,Ca^2＋ ＋ Mg^2＋ ,depleted of K^＋ ,rich of C1^- ,deple-ted of F^- and SO4^2-, rich of CO2, these data suggest that multi-source characteristics of hydro-thermal fluids derived from deep hot brine and seawater; Biotite ^40Ar/39 Ar age of mineralization period alteration measured value of 135.52 Ma±0.82 Ma. The isotopic ages close to Jianglang dome porphyritic biotite granite intrusions K-Ar isotopic age （131 Ma±5 Ma） and the Jinping nappe shear taeniolite K-Ar isotopic age （129 Ma-120 Ma） ,these data suggest that main miner-alization and regional tectonic-magmatic events occurred in the same period. The paper analyses the geological characteristics of Liwu Cu-Zn deposit and researchs the genesis and the metalloge-netic rules. The paper indicates that Liwu Cu-Zn deposit is a marine sedimentary-metamorphose sulfuration deposit,the material source is polyphyletic and the mineralization is polyphase. Liwu Cu-Zn deposit is controlled by the stratum and the tectonic obviously,ore-hosting have repetitious superposition of magma-tectonic mineralizat

关 键 词：成矿规律 矿床成因 里伍铜锌矿床 

分 类 号：P618.41[天文地球—矿床学] P618.43[天文地球—地质学]