Qiongheba is a polymetallic ore concentration area located in the east margin of the Junggar Basin in Xinjiang, Northwest China. Because all three main types of metal deposits (porphyry-type copper, skarn-type iron-copper, and structural altered rock-type gold deposits) in this area are controlled strictly by fault structures and intrusions buried under the Quaternary sediments, the detection of concealed faults and intrusions is of great significance for mineral prospecting. We aim to make clear the faults and intrusions based on the high-precision gravity and magnetic data set. First, multiscale edge detection of gravity and magnetic data is used to distinguish and divide the faults system. Second, 3D recognition of concealed intrusions combining with 3D inversion and multiscale edge detection of gravity and magnetic is carried out to construct the 3D formation of concealed intrusions. Last, seven prospecting targets are proposed based on our research and existed regional geologic and geochemical information, and two of them have been confirmed to be rich in polymetal (Cu-Fe-Mo-Au in the Layikeleke deposit and Cu in the Baxi deposit) by drilling. Our research results not only proved the effectiveness of the combination method of 3D inversion and multiscale edge detection of gravity and magnetic data in the prospecting of concealed faults and intrusions, but they also provide abundant information for mineral exploration prediction in the Qiongheba area.

The Ashele ore concentration area is an important area for polymetallic ore concentration in Xinjiang, China. Scholars have made progress in understanding the ore-controlling structures, ore-bearing horizons, and metallogenic age of this area. However, there are still uncertainties about the 3D distributions of plutons, fault structures, and ore-bearing strata, which restrict the development of deep and peripheral ore prospecting and the discovery of new ore bodies in the area. This study proposes a geological–geophysical modeling method based on irregular sections and uses this method to establish a 3D geological–geophysical model based on physical property data, boreholes, surface geological maps, and geophysical data. The model shows that the study area has many hidden rock masses with various depths and shapes and fracture structures with complex shapes. The fault structure in the area is complex, and the ore bodies are controlled by the faults. The ore-bearing geological units (Ashele Formation) exhibit an obvious east–west-trending W-shaped fold structure. The deep part of the northern Ashele Formation extends northward slightly, and the southern Ashele Formation has thick strata, with depths generally greater than 2 km. Based on the information on deep structures provided by the model, three metallogenic prospective areas are predicted, which points out the direction for further prospecting work in the ore concentration area and shows that the adopted modeling method and process have good applicability for constructing 3D models of ore concentration areas with sparse data, large area, and complex geological structures. The proposed modeling method provides technical support for ore prospecting, particularly in the overburden area or ore concentration area with sparse data.

The No. VI ore block of the Galinge skarn system in the Qimantagh metallogenic belt, East Kunlun, contains proximal Fe-oxide mineralization and distal Pb–Zn sulfide mineralization that are spatially zoned and locally overprinted along faults and interlayer fracture zones. To constrain the controls on Fe–Pb–Zn zonation and overprinting within this ore block, we integrated LA–ICP–MS zircon U–Pb dating, zircon Lu–Hf isotopes, whole-rock major and trace elements, and in situ trace elements of magnetite, pyrite, chalcopyrite, pyrrhotite, and arsenopyrite. Zircon U–Pb ages indicate two Indosinian intrusive pulses: an early granodiorite at 235.1 ± 0.51 Ma and a younger granodiorite–quartz diorite at 229.52 ± 0.46 Ma. Excluding the hydrothermally altered sample ZK26804-805, the intrusive rocks are metaluminous, medium- to high-K calc-alkaline I-type granitoids mainly derived from remelting of ancient crustal material, with a greater juvenile crustal or mantle contribution in the younger phase. Magnetite is generally Zn-rich and Pb-poor, whereas late pyrite and chalcopyrite are enriched in Pb, Ag, Cd, and Bi; local Sb–As anomalies in magnetite and arsenopyrite indicate late hydrothermal overprinting. The Fe and Pb–Zn mineralization is best interpreted as staged products of one multipulse magmatic–hydrothermal system controlled not only by intrusive pulses but also by inherited structural pathways, host-rock reactivity, and evolving redox-sulfidation conditions. The interpretation of Sb–As enrichment in magnetite is therefore used cautiously because these elements may occur as lattice substitutions and/or micro- to nano-inclusions introduced or modified during retrograde alteration.

The Galinge deposit in East Kunlun, China is a large Fe-polymetallic skarn system with a significant by-product, Co, but the respective roles of magmatism, skarn evolution, and wall rock interaction in Co enrichment remain incompletely understood. We integrate zircon and garnet U–Pb geochronology, zircon Lu–Hf isotopes and trace elements, whole-rock geochemistry, and SEM-EDS and EPMA mineral chemistry. Granodiorite and diorite porphyry yield zircon U–Pb ages of 230.09 ± 0.91 Ma and 229.4 ± 1.3 Ma, respectively, whereas skarn garnet yields 224.4 ± 9.3 Ma, placing intrusion and skarn formation within a Late Triassic magmatic–hydrothermal system. Both suites are metaluminous, LREE-enriched, and Nb–Ta–Ti-depleted; zircon ε_Hf(t) values of −9.4 to −1.8 indicate the predominant reworking of older crustal material with variable input from a more radiogenic component. Strictly screened Ti-in-zircon temperatures and lattice strain Ce anomalies yield median apparent ΔFMQ values of +3.36 for granodiorite and +3.04 for diorite porphyry, indicating comparably oxidized magmatic conditions. The analyzed intrusions contain 2.12–13.4 ppm Co, whereas cobaltite and Co-bearing arsenopyrite contain 32.83–34.14 wt% and 0.38–4.53 wt% Co, respectively. Spatial and paragenetic relations place Co enrichment after magnetite deposition, during an early sulfide-stage hydrothermal sulfarsenide event within the skarn system. We infer that Late Triassic intrusions supplied heat, fluids, and ligands, whereas structural focusing and cooling, coupled with carbonate wall rock reactions and a reduction in carbonaceous or Fe²⁺-bearing domains, promoted As–S-rich Co precipitation; the leaching of intermediate–mafic wall rocks may have supplemented the Co inventory.

钴作为战略性关键金属,在新能源和高科技产业中具有不可替代的作用。东昆仑造山带作为中国重要的多金属成矿带,其晚三叠世岩浆-热液活动与铁多金属成矿关系密切。尕林格矿床作为该带的典型矽卡岩型铁多金属矿床,以铁为主,伴生铜、钴等元素,但其钴的赋存状态及富集机制尚不明确。本研究以Ⅱ矿段富钴矿石为研究对象,厘定钴的赋存状态及其沉淀机制,阐明控制矽卡岩成矿系统中钴富集的关键因素。研究发现,钴的赋存状态主要为辉砷钴矿和含钴毒砂,早期高温、高氧逸度、富Cl流体活化迁移钴元素,含矿热液与强烈还原的流体(奥陶纪祁漫塔格群变质沉积物和含碳泥质板岩)之间的相互作用引起的氧化还原变化是Co沉淀的关键控制因素。本文认为中基性火山岩可能提供了部分成矿物质,尕林格地区伴生钴矿的下一步找矿方向应重点关注岩浆-构造活跃带及还原性围岩环境,尤其是中基性火山岩较发育的矽卡岩成矿部位。