普朗超大型斑岩型Cu-Au矿床PGE赋存状态、迁移与富集机制研究

Pulang porphyry Cu-Au deposit is located in Shangri-La County, Yunnan Province. It is a recently discovered super large porphyry deposit which was formed in a typical island-arc setting in China. As most porphyry Cu deposits in island-arc settings not only contain significant amount of Au, but also usually accompanied by the platinum group elements (PGE) mineralization enrichment. Therefore, in this proposal project, an improved Carius tube dissolution method, in combined with isotope dilution, and inductively coupled plasma mass spectrometry (ID-ICP-MS) will be used to determine the PGE contents and occurrences for various types of rocks, ores, and sulfides from Pulang district. The analyzed results will be used to reveal the possible source and differentiation mechanism of the PGE in this deposit. Moreover, in combination with the study of fluid inclusions in quartz from different mineralization stages, migration and enrichment mechanism of PGE in magmatic-hydrothermal system will be further discussed. This project is not only help to understand that how PGEs transfer from the upper mantle to the granitic rocks, and then precipitate with sulfides from the fluid, but also provides some constructive suggestion for the ore smelting process in the coming Pulang mine.

普朗斑岩型铜-金矿床位于云南省香格里拉县境内，是近年来我国新发现的一个产于岛弧环境的超大型斑岩矿床。而典型的岛弧型斑岩铜矿床除了富金之外，通常还伴有铂族元素（PGE）的矿化富集。为此，本项目拟借助改进的Carius管法溶样，结合同位素稀释法，利用电感耦合等离子质谱仪（ID-ICP-MS）系统研究普朗超大型斑岩铜矿床中不同类型岩石、矿石及硫化物中的PGE含量与赋存状态，并试图揭示该矿床中PGE的来源与分异机制。此外，将结合不同成矿期次流体包裹体的研究，进一步探讨PGE在岩浆-热液体系中迁移与富集机制。该项目不仅对于研究PGE如何从上地幔进入花岗质岩石、从熔体进入流体并在硫化物中富集的机理具有重要的理论价值，而且还将为普朗矿山下一步在矿石冶炼过程中如何提取PGE提供一定的理论指导。