Geochemistry of the Kalatongke Ni–Cu–(PGE) sulfide deposit, NW China: implications for the formation of magmatic sulfide mineralization in a postcollisional environment

Xie-Yan Song,Xiang-Ren Li

doi:10.1007/s00126-008-0219-x

Abstract

The Kalatongke (also spelt as Karatungk) Ni–Cu–(platinum-group element, PGE) sulfide deposit, containing 33 Mt sulfide ore with a grade of 0.8 wt.% Ni and 1.3 wt.% Cu, is located in the Eastern Junggar terrane, Northern Xinjiang, NW China. The largest sulfide ore body, which occupies more than 50 vol.% of the intrusion Y1, is dominantly comprised of disseminated sulfide with a massive sulfide inner zone. Economic disseminated sulfides also occur at the base of the intrusions Y2 and Y3. The main host rock types are norite in the lower part and diorite in the upper part of each intrusion. Enrichment in large ion lithophile elements and depletion in heavy rare earth elements relative to mid-ocean ridge basalt indicate that the mafic intrusions were produced from magmas derived from a metasomatized garnet lherzolite mantle. The average grades of the disseminated ores are 0.6 wt.% Ni and 1.1 wt.% Cu, whereas those of the massive ores are 2 wt.% Ni and 8 wt.% Cu. The PGE contents of the disseminated ores (14–69 ppb Pt and 78–162 ppb Pd) are lower than those of the massive ores (120–505 ppb Pt and 30–827 ppb Pd). However, on the basis of 100% sulfide, PGE contents of the massive sulfides are lower than those of the disseminated sulfides. Very high Cu/Pd ratios (>4.5 × 104) indicate that the Kalatongke sulfides segregated from PGE-depleted magma produced by prior sulfide saturation and separation. A negative correlation between the Cu/Pd ratio and the Pd content in 100% sulfide indicates that the PGE content of the sulfide is controlled by both the PGE concentrations in the parental silicate magma and the ratio of the amount of silicate to sulfide magma. The negative correlations between Ir and Pd indicate that the massive sulfides experienced fractionation.

Highlights

The magmatic sulfide deposits in the Central Asian orogenic belt are hosted in a series of mafic–ultramafic intrusions in the Maksut zone (E Kazakhstan), the Kalatongke and the Huangshan zones in Xinjiang (NW China) and the Hongqiling zone in NE China
Since the South Maksut Ni–Cu sulfide deposits were discovered in the 1970s, many studies have been carried out [Khromykh et al, 2013]
This paper focuses on noble metal concentrations and mineralization of the South Maksut sulfide ores and crust of weathering, which is located on the eastern part of massif (Fig. 1)

Summary

Introduction

The magmatic sulfide deposits in the Central Asian orogenic belt are hosted in a series of mafic–ultramafic intrusions in the Maksut zone (E Kazakhstan), the Kalatongke and the Huangshan zones in Xinjiang (NW China) and the Hongqiling zone in NE China. In the Maksut zone there are several intrusions, the best studied from which is the South Maksut intrusion with Cu–Ni–PGE mineralization. The South Maksut Ni–Cu deposit contains 0.08 Mt nickel and 0.1 Mt copper with average grades of 0.4 wt. Since the South Maksut Ni–Cu sulfide deposits were discovered in the 1970s, many studies have been carried out [Khromykh et al, 2013]. This paper focuses on noble metal concentrations and mineralization of the South Maksut sulfide ores and crust of weathering, which is located on the eastern part of massif (Fig. 1)

Methods

Results

Conclusion