论文部分内容阅读
滇西羊拉铜矿是近年来发现的大型铜矿床。作者系统地研究了该矿床的S、Pb、C、O、Si同位素组成,研究表明该矿床不同矿石的硫同位素组成变化范围一致,其平均值靠近零值且具有塔式分布特征,表明硫来源于上地幔或岩浆作用;该矿床矿石中方解石的C、O同位素组成与矿区大理岩的C、O同位素组成明显不同,其δ13C(PDB)为-3.27‰~-4.89‰,与上地幔射气及岩浆作用形成的CO-2的碳同位素组成一致,因此矿石中方解石中碳亦来源于上地幔射气或岩浆作用;铅同位素特征表明早期热水沉积形成的块状硫化物矿石铅主要来源于上地壳,而中晚期形成的夕卡岩型矿石及蚀变破碎带型矿石的铅具有上地幔铅的特征。
The Yunnan Yangla copper deposit is a large copper deposit discovered in recent years. The authors systematically studied the S, Pb, C, O and Si isotopic compositions of this deposit. The results show that the sulfur isotope compositions of different ores in this deposit vary in a wide range. Their average values are close to zero and have tower distribution characteristics, indicating that sulfur sources In the upper mantle or magmatism, the C and O isotopic composition of calcite in this ore deposit is obviously different from that of the marble in the ore area. The δ13C (PDB) of the calcite is -3.27 ‰ -4.89 ‰, which is close to that of the upper mantle gas And the carbon isotope composition of CO-2 formed by magmatism. Therefore, the carbon in calcite from the ore is also derived from the upper mantle radioactivity or magmatic activity. The characteristics of Pb isotopes indicate that the massive sulphide ore lead formed by early hydrothermal deposition is mainly derived from Upper crust, while the formation of mid-late skarn-type ore and alteration crushed ore lead has the upper mantle lead characteristics.