The Darbut tectono‐magmatic zone in the West Junggar terrane (NW China) is an important component of the famous Circum‐Balkhash‐West Junggar metallogenic province. In this region, the discovery of some small but high‐quality Cu–Au deposits/prospects indicate substantial exploration potential for large porphyry Cu–Au deposits, for example, those in the neighbouring Kazakhstan. In this contribution, we concluded that the Dulunhe granite and small ore‐bearing granitoids in Baogutu are adakitic petrogenesis, and the Buerkesitai and Tasikuola granites (formed by magma mixing) are well comparable with the Xiaerpu granite. In summary, granitoids with similar petrogenesis and mineralization are distributed on both sides of the Darbut fault zone and show good correlations with the sinistral movement of the latter. We propose that the porphyry Cu–Mo–Au mineralization potential of the small calc‐alkaline I‐type granitic stocks in southern West Junggar region is significantly higher than that of alkaline A‐type large granitic batholiths. Besides, the magma mixing‐derived and adakitic granites have great prospecting potentialities. We argue that the Cu–Mo–Au mineralization in the Darbut tectono‐magmatic zone was originally E‐W trending, and then displaced by the Darbut sinistral strike‐slip faulting, instead of being controlled by NE‐NNE trending faults. The main regional mineralization pattern comprises a northern magmatic‐hydrothermal Au belt (~318 Ma), a middle porphyry Mo belt (~296 Ma), and a southern adakite and magma mixing granite‐related Cu–Au belt (~313 Ma). We infer that the Bieluagaxi Au belt may continue eastward to east of Sartohay.

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The study area in the West Junggar Basin is known to be rich in hydrothermal gold deposits and occurrences, even though there has been minimum exploration in the area. It is here hypothesised that this area could host more gold deposits if mineral exploration methods were to be reinforced. This research is aimed at identifying geochemical anomalies of Au, and determining possible factors and conditions which facilitate the formation of anomalies by referring to As and Hg as gold pathfinders. Geostatistical analyst techniques have been applied to 9,852 stream sediments and bedrock data collected on a total surface of 1,280 km2 of West Junggar, Xinjiang (northwest China). The kriging interpolation and quantile-quantile plot methods, combined with statistical methods, successfully identified both Au and its pathfinders’ anomalies. In the present study, median was considered as background values (10.2 ppm for As, 9.13 ppb for Hg and 2.5 ppb for Au), whereas the 95th percentile were threshold values (28.03 ppm for As, 16.71 ppb for Hg and 8.2 ppb for Au) and values greater than thresholds are geochemical anomalies. Moreover, the high concentrations of these three discovered elements are caused primarily by hydrothermal ore mineralisation and are found to be controlled mainly by the Hatu and Sartohay faults of a northeast-southwesterly direction as well as their related secondary faults of variable orientation, which facilitate the easy flow of hydrothermal fluids towards the surface resulting in the formation of geochemical anomalies. Most of anomalies concentration of Au are found near the mining sites, which indicates that the formation of new Au anomalies is influenced by current or previous mining sites through geological or weathering processes. In addition, the low concentration of gold and its pathfinders found far from active gold mine or faults indicates that those anomalies are formed due to primary dispersion of hosting rock.

This article examines the impact of artisanal and small-scale mining (ASM) on livelihood in mining communities in Rwanda (Rutsiro) where wolframite and coltan are mined. The paper discusses the development of ASM and other entrepreneur activities, in particular agriculture. With ASM activities, there is environmental degradation on the one hand but also an improvement in the well-being of the local population on the other. The 3T (tin, tungsten, tantalum) minerals extracted by ASM are used in the electronics industry for products such as smartphones, tablets, and laptops, which are mainly consumed in the developed world. Based on questionnaires and structured research with miners, it was determined how ASM affects their lives, or whether there is a deterioration or improvement in their well-being. The research builds on previous field research in Rwanda. Because of mining, communities in the mining areas have access to health care, they can pay tuition fees, insurance, etc. On the other hand, the lives of miners are endangered by respiratory diseases, accidents in mines, landslides in mining areas, and other negative environmental impacts. The extraction of these minerals, however, may lead to a worse quality of life for the miners responsible for the extraction in developing countries. This different view is also illustrated by the fact that miners themselves often do not know what 3T minerals are used for. ASM benefits miners from an economic perspective but may worsen their quality of life due to unsuitable working conditions. This study covers a broader understanding of socioeconomic impacts of ASM and tries to point out the lack of awareness about the mining of minerals important for the daily use of modern technologies. This article would like to contribute to the larger debate about the lack of awareness of the origin of 3T minerals.

The Chinese Altai as a key part of the Central Asian Orogenic Belt is characterized by wide outcrops of Palaeozoic granitoids and minor mafic plutons. It is widely accepted that Devonian ridge subduction played an important role in the tectonic evolution of the Chinese Altai. However, Carboniferous magmatism related to ridge subduction has received little attention. Here, we report zircon U–Pb age and whole‐rock geochemistry of the Kezijiaer gabbros in the southern Chinese Altai, aiming to elucidate their emplacement age and petrogenesis and tectonic setting. Laser ablation inductively coupled plasma mass spectrometry zircon U–Pb dating shows that the Kezijiaer gabbros were emplaced in the Early Carboniferous with a crystallization age of 348 ± 3 Ma (mean square of weighted deviates = 0.46). Geochemically, the Kezijiaer gabbros exhibit low SiO2, high MgO, Fe2O3, Ni, and Cr concentrations, as well as enrichments of light rare earth elements and large‐ ion lithophile elements (e.g., Rb, Ba, Th, and U) relative to high‐field‐strength elements and heavy rare earth elements. Meanwhile, they have high TiO2, Nb/Ta, Zr/Hf, and Ti/V and low La/Yb values. These features show that the gabbros share geochemical signatures of both island arc basalt and mid‐ocean ridge basalt. Together with low La/Sm, Sm/Yb, and Dy/Yb ratios, it is suggested that the Kezijiaer gabbros mainly originated from partial melting of a spinel lherzolite mantle wedge metasomatized by subduction‐related fluids and sediment melts with input of asthenospheric components, subsequently followed by fractional crystallization of olivine and clinopyroxene. Taking into account regional geology and published data, we argue that an Early Carboniferous ridge subduction regime responsible for the Kezijiaer gabbros might have also exerted a pivotal role in the tectonic evolution processes of the Chinese Altai in the Palaeozoic.