中文摘要:通过离子探针、K-Ar法和Re-Os法测得冈底斯斑岩铜矿带的成矿年龄。冈底斯斑岩铜矿带中驱龙石英二长花岗斑岩的SHRIMP年龄为(17.58±0.74) Ma，冲江二长花岗斑岩的SHRIMP年龄为(15.60±0.52) Ma，冲江闪长玢岩的SHRIMP年龄为(14.54±0.65) Ma。驱龙和冲江含矿斑岩钾长石的K_Ar年龄分别为(16.43±0.31) Ma和(15.77±0.45) Ma，矿石中辉钼矿的Re-Os年龄分别为（15.99±0.32) Ma和(14.85±0.69) Ma。因此驱龙和冲江斑岩铜矿的成矿年龄约束于(17.58±0.74) Ma～(14.85±0.69) Ma之间。驱龙石英二长花岗斑岩为强矿化岩石，冲江二长花岗岩斑岩为中等矿化岩石，冲江闪长玢岩为未矿化岩石，三者的年龄依次变小，放射性元素206Pb、U和Th含量则依次增高。这表明随着壳源物质混合的增强，铜矿化渐弱。立足于大西洋底栖有孔虫氧同位素变化和印度洋北部海底沉积扇的沉积速率变化来看青藏高原隆升，认为玉龙矿带和冈底斯矿带斑岩铜矿是在青藏高原两次最明显的地壳运动中形成的。
Abstract:Zircon samples from the Qulong quartz monzogranite porphyry in the Gangdese porphyry copper belt, from the Chongjiang monzogranite porphyry and from the Chongjiang diorite porphyrite give SHRIMP U-Pb ages of (17.58±0.74) Ma, (15.60±0.52) Ma and (14.54±0.65 Ma), respectively. K-Ar ages for K_feldspathic alteration of the mineralized porphyry in the Qulong porphyry copper deposit and in the Chongjiang porphyry deposit are (16.43±0.31) Ma and (15.77±0.45) Ma, respectively, while Re-Os ages for molybdenite from ores of these two deposits are (15.99±0.32) Ma and (14.85±0.69) Ma, respectively. Thus the metallogenic ages for the Qulong and the Chongjiang porphyry copper deposits are constrained between (17.58±0.74) Ma and (14.85±0.69) Ma. From strongly mineralized Qulong quartz monzogranite porphyry through intermediately mineralized Chongjiang monzogranite porphyry to barren Chongjiang diorite porphyrite, the SHRIMP U-Pb ages of zircon become younger and younger, and the radiating 206Pb, U and Th contents grow higher and higher. This suggests that the intensity of mineralization decreases wtih the mixture of curst material. Variations in δ18O values of foraminifera at the bottom of the Atlantic Ocean and in sedimentation rate on submarine sedimentary fans in the north Indian Ocean indicate that mineralizations in the Yulong and the Gangdese porphyry copper belts were related respectively to the Gangdisê and the Hemalayan movements. The SHRIMP U-Pb ages of zircon from host rocks in the Yulong prophyry copper belt vary from (40.9±0.1) Ma to (35.0±0.52) Ma, while the SHRIMP U_Pb ages of zircon from host rocks in the Gangdese porphyry copper belts range between (17.58±0.74) Ma and (15.60±0.52) Ma.
文章编号：
中图分类号：
文献标志码：
基金项目:国土资源部大地调项目(1999 10200246)和国家重点基础研究发展规划(2002CB4126010)
引用文本：
芮宗瑶，侯增谦，曲晓明，张立生，王龙生，刘玉琳.2003.冈底斯斑岩铜矿成矿时代及青藏高原隆升[J].矿床地质,22(3):217~225.2003.Metallogenetic Epoch of Gangdese Porphyry Copper Belt and Uplift of Qinghai-Tibet Plateau[J].Mineral Deposits22(3):217~225
图/表
