Platinum Group Element Character of the Getashankou Ni-Cu Deposit in East Tianshan and its Effect on Mineralization Process

The small scale Getashankou Ni-Cu deposit is located at the eastern section of the Huangshan-Jingerquan-Tulargen Ni-Cu ore belt, East Tianshan. This deposit is mainly composed by speckled ore and sparse disseminated ore. In these ores, Ni contents range from 0.16% to 1.39%, while the Cu contents vary from 0.02% to 1.21%, and the Ni/Cu ratios change from 1.15 to 7.01. The contents of ∑PGE are relative low, which range from 13.11×10^-9 to 828.09×10^-9, and the Pd/Ir ratios vary from 13.9 to 20.8, indicating that the PGE characters of ores are almost unaffected by hydrothermal activity. The PGE shows the original characteristics of the deposit. Distribution patterns of PGE in these ores are enriched in Pt and Pd. In the geochemical data of these ores, the relationship between Ni/Cu and Pd/Ir indicate that the primitive magma is picritic magma whose PGE are not depleted, which is similar with other typical Ni-Cu deposits in China. Small amount of sulfide was separated in the deep chamber, which result in the loss of PGE in these ores. The elements among PGE show positive correlations, indicating that the sulfides didn't experienced effectly crystallization.