The Kargah Cu-Pb polymetallic deposit is a newly discovered ore deposit from the Gilgit-Baltistan region, located in the Kohistan Island Arc, northern Pakistan. However, this area is poorly researched on the ore genesis, and its origin and the evolution of its magmatic-hydrothermal system remain unclear. Three stages of mineralization were identified, including quartz-pyrite, quartz-sulfide, and carbonate representing early, middle, and late stages, respectively. The major ore minerals are pyrite, chalcopyrite, galena, and zincian tetrahedrite with minor native silver, and native gold mainly distributed in pyrite. Here, we present a systematic study on ore geology, hydrothermal alterations, trace element composition of pyrite, fluid inclusions, and isotopes (S and Pb) characteristics to gain insights into the nature of the ore-forming fluids, types of unknown deposits, and hydrothermal fluid evolution. The high Co/Ni ratio (1.3–16.4) and Co content (average 1201 ppm), the low Mo/Ni ratio (0.43–0.94) and Mo contents (average 108 ppm) of both Py-I and Py-II suggest a mafic source for the mineralization. The Au-Ni plots, Co-As-Ni correlation, and the δ³⁴S values range from −2.8 to 6.4‰ (average of 3.4‰) indicating the affiliation of the mineralization with a mantle-derived magmatic-hydrothermal provenance. The Pb isotope data showing the narrow variations in ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb values suggest a single lead source from crustal-derived materials. The microthermometry data suggest that the dominant mechanisms are fluid boiling and mixing for mineral precipitation at temperatures ranging between 155 and 555 °C, and represent an intrusion-related magmatic-hydrothermal environment for the Kargah Cu-Pb polymetallic deposit.

The color-change sapphire occurs in sillimanite-biotite gneiss in Fuping County Hebei province, China, is one of most famous sapphire deposits in China. However, the color genesis, mechanisms of color changing and compositional characteristics of the sapphire remain enigmatic. In this contribution, the coloration in the Fuping sapphire, color changing mechanisms and, compositional characteristics were studied by conventional gemological instruments in conjunction with ultraviolet-visible spectroscopy and Laser ablation inductively coupled plasma mass spectrometer. The results show that the Fuping sapphire is characterized by purple-blue-to-purple-red changed effect and column-shaped, waist drum-shaped with higher degree of euhedral crystal. Reddish brown rutile inclusions with 120° crossed cleavage are commonly observed. The dominant coloring element of the Fuping sapphire is Fe³⁺, and subordinate elements are Fe²⁺, Cr³⁺ and V³⁺. The color-change effect is caused by trace elements Cr³⁺ and V³⁺. The chemical compositions of Fuping color-change sapphires are analogous to those of metamorphic blue sapphires. When geochemically compared with sapphires from Isalo/Ilakaka deposit in Madagascar, Ratnapura deposit in Sri Lanka and Mogok in Myanmar, the Fuping color-change sapphires have distinctly higher rare element contents of Fe, Cr and Ga.

In snow-covered mountainous terrain like the Himalayas, avalanches are responsible for the majority of fatalities and property damage. Statistics and information on its possibility are typically poor and unavailable in complex terrains. Recognizing avalanche-prone locations and making avalanche susceptibility maps available can assist decision-makers and planners in developing successful avalanche risk reduction strategies. The goal of this research is to use a multi-criteria decision analysis–analytical hierarchy process model in a GIS to create an avalanche susceptibility map for the Shigar valley region, North Pakistan. Slope, aspect, curvature, elevation, terrain roughness, and ground cover are the most important avalanche occurrence components in this model. The analyzed factors were created using STRM DEM and Landsat 8 satellite data. The correctness of the findings is determined by looking at the avalanche inventory map of recorded avalanche sites. The area under the ROC curve (ROC-AUC) method was used to calculate the prediction accuracy. Using ROC-AUC, the validation findings have a prediction accuracy of 91%. Decision-makers on a local and regional level can apply the present study approach in the future to improve avalanche preparedness and planning.

The southern region of the South China Block hosts a super-large metallogenic province. However, the Mesozoic differential metallogeny between the southern Cathaysia Block (W-Sn) and the southern Yangtze Block (Au-Sb) remains enigmatic. To characterize the crustal architecture beneath different metallogeny belts, we integrate 3239 published ε_Hf(t) values of synmagmatic zircons from Mesozoic igneous rocks and corresponding whole-rock ε_Nd(t) datasets to generate coupled Hf–Nd isotopic mappings. The results show that ε_Hf(t) values range from −19.3 to +11.6 (T_DM2: 464–2419 Ma) and ε_Nd(t) values are from −12.2 to +5.0 (T_DM2: 580–2008 Ma) in the southern part of South China Block. High ε_Hf(t) (−4~+11.6) and ε_Nd(t) (−4~+5.0) zones are concentrated along the Honghe Fault and Chenzhou–Linwu Fault systems, while low-value Hf–Nd isotopic (ε_Hf(t) = −10.6 to −4; ε_Nd (t) = −12.2 to −4) zones are mainly distributed in the interior of the southern Yangtze Block. The W-Sn deposits in the southern Cathaysia Block are genetically linked to the heterogeneous ε_Hf(t)-ε_Nd(t) isotopic domains. The ore-forming materials of these high-temperature W-Sn polymetallic deposits may primarily derive from crust hybrid magmas that have undergone multistage crustal reworking. In contrast, low-temperature Au-Sb deposits in the northern Youjiang basin are distributed in areas characterized by elevated ε_Hf(t)-ε_Nd(t) isotopic signatures, which are primarily derived from reworked crust with significant mantle contributions. Most magmatic rock-associated Au deposits tend to cluster at the boundaries of Hf-Nd isotopic anomalies, which indicates the contribution of crust-mantle interaction to Au mineralization. Our Hf-Nd isotopic mappings reveal that mantle-crust deep-seated process controls the Mesozoic differential metallogeny between the southern Cathaysia Block (W-Sn) and the southern Yangtze Block (Au-Sb).

This study presents first report on hydrothermal polymetallic ore deposit in the Sharote Valley some 29 km North-West from Gilgit city in the northern Kohistan Island Arc Gilgit Baltistan. The deposit is formed of extending sulphide veins. The minerals in associated rocks are identified as quartz, biotite, muscovite, epidote, plagioclase and hornblende amphibole with accessory minerals chlorite, sericite with opaques. The XRF analysis of investigated rocks shows that the major oxides are Na2O (6.10-6.70 wt. %), CaO (2.73-5.49 wt. %), SiO2 (66.6968.10 wt. %), Fe2O3 (1.0-3.92 wt. %) Al2O3 (4.55-8.59 wt. %), and K2O (2.1-2.28 wt. %), which indicate that the associated rock is quartz monzonite which is more Calc-alkaline and less tholeiitic based on AFM diagram. Based on the analysis of ore samples using Atomic Absorption Spectroscopy, the trace elements Cr, Zn, Co, Pb, Fe, Mn, Ni, Au, and Ag are investigated. The concentration (Wt.%) of Au, Ag, Cu, Cr, Pb, Ni, Co, Zn are 0.04-0.296, 4.242.55, 851.25-20025, 2.25-12.9, 2.1-1105, 0.1-28.25, 78.75-252.5 and 17.45-280.45. Cu shows positive trends with Co, Cr, Zn, Ag and Pb. These geochemical signatures, petrographic results and field observations show that sulphide veins dominated by chalcopyrite and bornite, accompanied by secondary azurite and malachite, and hosted within quartz monzogranite are best interpreted as products of a magmatic-hydrothermal system linked to the emplacement and crystallization of the granitic intrusion. As magma evolved, metals such as Cu, Au, Pb, and Fe, along with volatiles (H₂O, S, Cl, and CO₂), became progressively concentrated in the residual melt. Upon reaching fluid saturation, metal-bearing hydrothermal fluids were exsolved from the crystallizing quartz monzogranite. These fluids, enriched in Cu–Au complexes, constituted the primary source of the sulphide mineralization.

Late Early Jurassic continental arc magmatism in the northern Greater Khingan Range enables the investigation of complicated tectonic processes associated with the subduction and closure of the Mongol–Okhotsk Ocean. To further clarify the timing, genesis, and geodynamic mechanisms driving the magmatic activity during this period, the present study addresses these critical questions by integrating zircon U–Pb geochronological, geochemical, and isotopic analyses of a wide variety of igneous rocks, including gabbro, gabbro-diorite, granodiorite, porphyritic monzogranite, and biotite-bearing monzogranite from the Fushan region. Zircon U–Pb geochronology constrains the timing of magmatic activity to 184–179 Ma, coinciding with active subduction phases. Geochemical data reveal arc-like signatures characterized by enrichment in light rare-earth elements (LREEs) and large-ion lithophile elements (LILEs), together with pronounced depletion in high field strength elements (HFSEs). A comprehensive analysis of geochemical and Sr–Nd–Hf isotopic signatures suggests that the mafic rocks originated from an enriched lithospheric mantle modified by subduction-related fluids and sediment-derived melts. By contrast, the granodiorite and porphyritic monzonite exhibit adakitic characteristics, indicating partial melting of the thickened Mesoproterozoic lower crust with contributions from mantle-derived or newly formed crustal material. The biotite-bearing monzogranite, with its pronounced Eu anomaly and lower zircon saturation temperatures, reflects advanced magmatic differentiation from a shallower source. These findings indicate extensive crust–mantle interactions during the southward subduction of the Mongol–Okhotsk Ocean, driven by high-angle subduction and slab rollback.