First Data on the Concentrations and Distribution of Noble Metals in Ni-Cu Sulfide Ores of the South Maksut Deposit (East Kazakhstan)

Abstract

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. % Ni and 0.5 wt. % Cu, respectively (BAST, 2017). 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).Deposit geology and petrography. Early studies showed that the pluton is a small lopolith-like body [Ermolov et al., 1983;Khromykh et al., 2013]. The Maksut intrusion is mainly composed of olivine dolerite, olivine norite, and gabbronorite ( Fig. 1, a). Olivine dolerite displays ophitic and poikilophitic textures. It consists of olivine with f=20-24 (10-20 %); two generations (60-70 vol. %) of plagioclase: 85-55 % An and 40-25 % An; clinopyroxene as subcalcic augite with f=30-40 (10-25 %); biotite (3-4 vol. %);

Geological History of the Great Altai: Implications for Mineral Exploration

“…Synthesis and analysis of the geological and mineralization data from the Great Altai region open new perspectives on the evolution of major metallogenic structures as a basis for exploration criteria, especially in poorly investigated and buried areas. The mineralization processes, with formation of base, rare, and precious metals and other types of mineral deposits, developed in different tectonic settings in the course of its long history (Table 2) [27,30,[48][49][50]52,61,63,67,[72][73][74][75][76][77][78][79][80]. [72,80] Au in kaolinite-sericite weathering profiles Zhanan deposit [74] During the Early Paleozoic orogenic cycle, the Great Altai territory was occupied by the Zaysan oceanic basin, a part of the Paleo-Asian ocean ([1,3-5], etc.…”

“…The postcollisional stage was the time of voluminous Early Permian ultramafic-mafic and granitic magmatism [23] in a setting of general extension and strike-slip in the Great Altai territory. Ultramafic and mafic small intrusions in the Zharma-Saur belt host Cu-Ni mineralization, e.g., Maksut deposit [27,75,83]. The Akzhal and Ashaly gold deposits in the West Kalba belt occur within diorite and granodiorite small intrusions [76].…”