Search Results (372)

Thermodynamic simulations of fluid–rock interactions provide valuable insights into mineral deposit formation mechanisms. This study investigates the Pulang porphyry Cu-Au deposit in the Sanjiang Tethys Orogen, employing both Gibbs energy minimization (GEM) and the Law of mass action (LMA) method to understand alteration overprinting and metal precipitation. The modeling results suggest that the ore-forming fluid related to potassic alteration was initially oxidized (ΔFMQ = +3.54~+3.26) with a near-neutral pH (pH = 5.0~7.0). Continued fluid–rock interactions, combined with the input of reduced groundwater, resulted in a decrease in both pH (4.8~6.1) and redox potential (ΔFMQ~+1), leading to the precipitation of propylitic alteration minerals and pyrrhotite. As temperature further decreased, fluids associated with phyllic alteration showed a slight increase in pH (5.8~6.0) and redox potential (ΔFMQ = +2). The intense superposition of propylitic and phyllic alteration on the potassic alteration zone is attributed to the rapid temperature decline in the magmatic–hydrothermal system, triggering fluid collapse and reflux. Mo, mainly transported as HMoO₄⁻ and MoO₄⁻², precipitated in the high-temperature range; Cu, carried primarily by CuCl complexes (CuCl₄⁻³, CuCl₂⁻, CuCl), precipitated over intermediate to high temperatures; and Au, transported as Au-S complexes (Au(HS)₂⁻, AuHS), precipitated from intermediate to low temperatures. This study demonstrates that fluid–rock interactions alone can account for the observed sequence of alteration and mineralization in porphyry systems. Full article

Alkaline carbonatite complexes are formed by magmatic, hydrothermal, and weathering geological events, which modify the minerals present in the rocks, resulting in ores with varied metallurgical behavior. To better spatially distinguish ores with distinct plant responses, creating a 3D geometallurgical block model was necessary. To establish the clusters, four different algorithms were tested: K-Means, Hierarchical Agglomerative Clustering, dual-space clustering (DSC), and clustering by autocorrelation statistics. The chosen method was DSC, which can consider the multivariate and spatial aspects of data simultaneously. To better understand each cluster’s mineralogy, an XRD analysis was conducted, shedding light on why each cluster performs differently in the plant: cluster 0 contains high magnetite content, explaining its strong magnetic yield; cluster 3 has low pyrochlore, resulting in reduced flotation yield; cluster 2 shows high pyrochlore and low gangue minerals, leading to the best overall performance; cluster 1 contains significant quartz and monazite, indicating relevance for rare earth elements. A hierarchical indicator kriging workflow incorporating a stochastic partial differential equation (SPDE) trend model was applied to spatially map these domains. This improved the deposit’s circular geometry reproduction and better represented the lithological distribution. The elaborated model allowed the identification of four geometallurgical zones with distinct mineralogical profiles and processing behaviors, leading to a more robust model for operational decision-making. Full article

The Sidi Aissa Pb-Zn-(Ag) District, located within the Nappe Zone of northern Tunisia, has been reinterpreted as a typical intermediate-sulfidation (IS) epithermal mineralization system based on field observations and lithogeochemical analyses. Previously described as vein-style Pb-Zn deposits, the local geological framework is dominated by extensional normal faults forming half-grabens. These faults facilitated the exhumation of deep Triassic autochthonous rocks and the extrusion of 8-Ma rhyodacites and Messinian basalts. These structures, functioning as pathways for magmatic-hydrothermal fluids, facilitated the upward migration of acidic fluids, which interacted with the surrounding wall rocks, forming a subsurface alteration zone. The mineralization, shaped by Miocene extensional tectonics and magmatic activity, occurred in three stages: early quartz-dominated veins, an intermediate barite-rich phase, and late-stage supergene oxidation. Hydrothermal alteration, characterized by silicification, argillic, and propylitic zones, is closely associated with the deposition of base metals (Pb, Zn) and silver. The mineral assemblage, including barite, galena, sphalerite, and quartz, reflects dynamic processes such as fluid boiling, mixing, and pressure changes. Full article

The Mazenod Lake region of the southern Great Bear Magmatic Zone (GBMZ) of the Northwest Territories, Canada, comprises the north-central portion of the Faber volcano-plutonic belt. Widespread and abundant surface exposure of several coalescing hydrothermal systems enables this paper to document, without ambiguity, the relationships between geology, structure, alteration, and mineralization in this well exposed iron-oxide–copper–gold (IOCG) mineral system. Mazenod geology comprises rhyodacite to basaltic-andesite ignimbrite sheets with interlayered volcaniclastic sedimentary rocks dominated by fine-grained laminated tuff sequences. Much of the intermediate to mafic nature of volcanic rocks is masked by low-intensity but pervasive metasomatism. The region is affected by a series of coalescing magmatic–hydrothermal systems that host the Sue–Dianne magnetite–hematite IOCG deposit and several related showings including magnetite, skarn, and iron oxide apatite (IOA) styles of alteration ± mineralization. The mid to upper levels of these systems are exposed at surface, with underlying batholith, pluton and stocks exposed along the periphery, as well as locally within volcanic rocks associated with more intense alteration and mineralization. Widespread alteration includes potassic and sodic metasomatism, and silicification with structurally controlled giant quartz complexes. Localized tourmaline, skarn, magnetite–actinolite, and iron-oxide alteration occur within structural breccias, and where most intense formed the Sue–Dianne Cu-Ag-Au diatreme-like breccia deposit. Magmatism, volcanism, hydrothermal alteration, and mineralization formed during a negative tectonic inversion within the Wopmay Orogen. This generated a series of oblique offset rifted basins with continental style arc magmatism and extensional structures unique to GBMZ rifting. All significant hydrothermal centers in the Mazenod region occur along and at the intersections of crustal faults either unique to or put under tension during the GBMZ inversion. Full article

The Shabaosi gold field is located in the western Mohe Basin, part of the northern Great Xing’an Range, NE China, and contains multiple gold deposits. However, the sources of the ore-forming materials, the fluid evolution, and the genesis of these gold deposits have been disputed, especially regarding the classification of these deposits as either epithermal or orogenic gold systems. Based on detailed field geological investigations and previous research, we conducted systematic research on the Shabaosi, Sanshierzhan, Laogou, and Balifang gold deposits using fluid inclusion and H-O-S-Pb isotope data, with the aim of constraining the fluid properties, sources, and mineralization processes. Fluid inclusion analyses reveal diverse types, including vapor-rich, vapor–liquid, CO₂-bearing, CO₂-rich, and pure CO₂. Additionally, only a very limited number of daughter mineral-bearing fluid inclusions have been observed exclusively in the Laogou gold deposit. During the early stages, the peak temperature primarily ranged from 240 °C to 280 °C, with salinity concentrations between 6 and 8 wt% NaCl equiv., representing a medium–low temperature, low salinity, and a heterogeneous CO₂-CH₄-H₂O-NaCl system. With the influx of meteoric water, the fluids evolved gradually into a simple NaCl-H₂O system with low temperatures (160–200 °C) and salinities (4–6 wt%). The main mineralization stage exhibited peak temperatures of 220–260 °C and salinities of 5–8 wt% NaCl equiv., corresponding to an estimated formation depth of 1.4–3.3 km. The δD_V-SMOW values (−138.3‰ to −97.0‰) and δ¹⁸O_V-SMOW values (−7.1‰ to 16.2‰) indicate that the magmatic–hydrothermal fluids were progressively diluted by meteoric water during mineralization. The sulfur isotopic compositions (δ³⁴S = −0.9‰ to 1.8‰) and lead isotopic ratios (²⁰⁸Pb/²⁰⁴Pb = 38.398–38.579, ²⁰⁷Pb/²⁰⁴Pb = 15.571–15.636, and ²⁰⁶Pb/²⁰⁴Pb = 18.386–18.477) demonstrate that the gold predominantly originated from deep magmatic systems, with potential crustal contamination. Comparative analyses indicate that the Shabaosi gold field should be classified as a epizonal orogenic gold system, which shows distinct differences from epithermal gold deposits and corresponds to the extensional tectonic setting during the late-stage evolution of the Mongol–Okhotsk orogenic belt. Full article

The Qieliekeqi siderite deposit, located in the Tashkurgan block of western Kunlun, is a carbonate-hosted iron deposit with hydrothermal sedimentary features. This study integrates whole-rock geochemistry, stable isotopes, and zircon U–Pb–Hf data to investigate its metallogenic evolution. Coarse-grained siderite samples, formed in deeper water, exhibit average Al₂O₃/TiO₂ ratios of 29.14, δEu of 2.69, and δCe of 0.83, indicating hydrothermal fluid dominance with limited seawater mixing. Banded samples from shallower settings show an average Al₂O₃/TiO₂ of 17.07, δEu of 3.18, and δCe of 0.94, suggesting stronger seawater interaction under oxidizing conditions. Both types are enriched in Mn, Co, and Ba, with low Ti and Al contents. Stable isotope results (δ¹³C_PDB = −6.0‰ to −4.6‰; δ¹⁸O_SMOW = 16.0‰ to 16.9‰) point to seawater-dominated fluids with minor magmatic and meteoric contributions, formed under open-system conditions at avg. temperatures of 53 to 58 °C. Zircon U–Pb dating yields an age of 211.01 ± 0.82 Ma, with an average εHf(t) of −3.94, indicating derivation from the partially melted ancient crust. These results support a two-stage model involving Late Cambrian hydrothermal sedimentation and Late Triassic magmatic overprinting. Full article

The Jiapigou mining district (>180 t Au) is an important gold district in China. For a long time, the ore genesis of the gold deposits in the Jiapigou district has been a subject of controversy and differing opinions, which has severely hindered metallogenic theories and mineral exploration. Here we present a comprehensive investigation including geology, fluid inclusions (FIs), and H–O–S isotopic data for the Naizhigou deposit in the Jiapigou district to elucidate the sources of orefluids and metals, as well as the metallogenic mechanism. The results show the following: (1) The Naizhigou deposit is characterized by quartz vein-type ores and is hosted in the Middle Jurassic granitic pluton. Native gold and sulfides were mainly deposited in the second stage (quartz–polymetallic sulfides) compared with the first (quartz–pyrite–molybdenite) and third (quartz–calcite) stages. (2) The FI studies indicated that the orefluids evolved from the early–main-stage CO₂–H₂O–NaCl system to the late-stage H₂O–NaCl system and have homogenization temperatures of 289–363, 210–282, and 124–276 °C and salinities of 4.1–20.9, 5.8–16.4, and 6.1–12.7 wt% NaCl equivalent, respectively. Fluid boiling and fluid mixing collectively controlled the precipitation of gold and ore-forming elements. (3) The δD values of the FIs hosted in quartz from the three stags range from −81 to −75 ‰, from −99 to −86 ‰, and from −110 to −101 ‰, while δ¹⁸O_water values of these FIs range from 5.3 to 5.9 ‰, from 1.1 to 5.2 ‰, and from −2.1 to −0.7 ‰, respectively. Pyrite samples from the three stages in the Naizhigou deposit have δ³⁴S values of 2.1 to 2.5 ‰, 3.1 to 4.3 ‰, and 3.8 to 3.9 ‰, respectively. The stable isotopes indicate that the orefluids and metals mainly originated from magma. A comparative study of regional observations reveals that the Naizhigou deposit is a magmatic-related mesothermal gold deposit, rather than a metamorphism-related orogenic gold deposit. The estimated ore-forming depths are 4.0–20.7 km, with exhumation depths of 4.1–5.5 km, which indicated that the deposit has been well preserved. Regionally, the new exploration strategies should place greater emphasis on work concerning ore-related plutons, ore-controlling faults, and hydrothermal alteration. Full article

Copper is typically acknowledged as a critical mineral and one of the vital components of various of today’s fast-growing green technologies. Porphyry copper systems, which are an important source of copper and molybdenum, typically consist of large volumes of hydrothermally altered rocks, mainly around porphyry copper intrusions. Mapping hydrothermal alteration zones associated with porphyry copper systems is one of the most important indicators for copper exploration, especially using advanced satellite remote sensing technology. This paper presents a sophisticated remote sensing-based method that uses ASTER satellite imagery (SWIR bands 4 to 9) to identify hydrothermal alteration zones by combining the discrete wavelet transform (DWT) and the median absolute deviation (MAD) algorithms. All six SWIR bands (bands 4–9) were analyzed independently, and band 9, which showed the most consistent spatial patterns and highest validation accuracy, was selected for final visualization and interpretation. The MAD algorithm is effective in identifying spectral anomalies, and the DWT enables the extraction of features at different scales. The Urmia–Dokhtar magmatic arc in central Iran, which hosts the Zafarghand porphyry copper deposit, was selected as a case study. It is a hydrothermal porphyry copper system with complex alteration patterns that make it a challenging target for copper exploration. After applying atmospheric corrections and normalizing the data, a hybrid algorithm was implemented to classify the alteration zones. The developed classification framework achieved an accuracy of 94.96% for phyllic alteration and 89.65% for propylitic alteration. The combination of MAD and DWT reduced the number of false positives while maintaining high sensitivity. This study demonstrates the high potential of the proposed method as an accurate and generalizable tool for copper exploration, especially in complex and inaccessible geological areas. The proposed framework is also transferable to other porphyry systems worldwide. Full article

Using pitchblende uranium ore GBW04420 as the standard material and through the secondary ion mass spectrometry (SIMS) technical method, the in situ U-Pb isotopic chronology characteristics of the main granite-type uranium deposits in the Xiazhuang ore field in the Nanling area of southern China were studied. Firstly, the suitability of GBW04420 as the in situ U-Pb isotopic dating standard material for uranium minerals was verified. On this basis, the in situ U-Pb isotopic ages of the three main granite-type uranium deposits in the Xiazhuang ore field, namely the Xianshi, Zhaixia, and Xiwang deposits, were obtained by SIMS dating. The results show that the overall mineralization period of the Xiazhuang ore field is mainly in Late Cretaceous and the Eocene-Oligocene. The mineralization ages indicate that the uranium deposits are of post-magmatic, medium-low temperature hydrothermal origin rather than the magmatic uranium deposit type. The hydrothermal fluids originate from the combined effect of the crust-mantle hydrothermal fluid and atmospheric precipitation; the uranium source originates from the extraction of the Indosinian-Early Yanshanian diagenetic granite by atmospheric water and partly from the mantle source of the basic dike. Full article

Haigou deposit, located in Dunhua City, southeast Jilin Province, NE China, is a large-scale gold deposit. The gold ore body is categorized into two types: quartz-vein type and altered rock type, with the quartz-vein type being predominant. The vein gold ore body primarily occurs within the monzonite granite and monzonite rock mass in the Haigou area and is controlled by fault structures trending northeast, northwest, and near north-south. In order to constrain the age and tectonic setting of quartz vein-type gold mineralization, we conducted a detailed underground investigation and collected samples of monzonite granite and pyroxene diorite porphyrite veins related to quartz-vein-type gold mineralization for LA-ICP-MS zircon U-Pb dating and whole-rock main trace element data testing to confirm that monzonite granite is closely related to gold mineralization. Pyroxene diorite porphyry and gold mineralization were found in parallel veins. The zircon U-Pb weighted mean ages of monzonite and pyroxene diorite porphyrite veins are 317.1 ± 3.5 Ma and 308.8 ± 3.0 Ma, respectively, indicating that gold mineralization in monzonite, pyroxene diorite porphyrite veins, and quartz veins occurred in the Late Carboniferous. The monzonite granite and pyroxene diorite porphyrite veins associated with quartz vein-type gold mineralization have high SiO₂, high K, and high Al₂O₃ and are all metaluminous high-potassium calc-alkaline rock series. Both of them are relatively enriched in light rare earth elements (LREE) and macroionic lithophile elements (LILE: Rb, Ba, K, etc.), but deficient in heavy rare earth elements (HREE) and high field strength elements (HFSE: Nb, Ta, P, Ti, etc.), the monzonitic granite Eu is a weak positive anomaly (δEu = 1.15–1.46), the pyroxene diorite porphyre dyke Eu is a weak positive anomaly (δEu = 1.09–1.13), and the Nb and Ta are negative anomalies. The Th/Nb values are 0.28–0.73 and 1.48–2.05, and La/Nb are 2.61–4.74 and 4.59–5.43, respectively, suggesting that diagenetic mineralization is the product of subduction in an active continental margin environment. In recent years, scholarly research on Sr, Nd, and Pb isotopes in Haigou rock masses has indicated that the magmatic source region in the Haigou mining areas is complex. It is neither a singular crustal source nor a mantle source but rather a mixed crust-mantle source, primarily resulting from the partial melting of lower crustal materials, with additional contributions from mantle-derived materials. In summary, the metallogenic characteristics, chronology data, geochemical characteristics, and regional tectonic interpretation indicate that at least one phase of magmatic-hydrothermal gold mineralization was established in the Late Carboniferous as a result of the subduction of the Paleo-Asian ocean plate at the northern margin of the North China Craton. Full article

The Bundelkhand granite (BG) constitutes the bulk of the granitoid complex in the Bundelkhand Craton and preserves imprints of its evolution from the magmatic to a protracted hydrothermal stage as deduced from the petrography. In order to reconstruct such a path of evolution in this study, thermobarometric calculations were attempted on the mineral chemistry of the major (hornblende, plagioclase, biotite) and minor (epidote, apatite) magmatic phases. They yielded magmatic temperatures and pressures (in excess of 700 °C and ~5 kbar), although not consistently, and indicate mid-crustal conditions at the onset of crystallization. Temperatures in the hydrothermal regime within the BG are better constrained by the chemistry of the chlorite and epidote minerals (340 to 160 °C) that conform with the ranges of homogenization temperatures of aqueous–biphase inclusions in matrix quartz in the BG and subordinate quartz veins. These reconstructions indicate that fluid within the BG evolved down to lower temperatures and towards the deposition of quartz and, more importantly, bears a striking similarity to the temperature–salinity characteristics of fluid in the giant quartz reef system. Scanty mixed aqueous–carbonic inclusions in the BG are indicative of the CO₂-poor nature of the BG magma and the exsolution of CO₂ at lower pressure (~2.6 kbar). The dominant mechanism of fluid evolution in the BG appears to be the incursion of meteoric fluid, which caused fluid dilution. Laser Raman microspectrometry reveals many types of solid phases in aqueous–carbonic inclusions in the BG domain. The occurrence of unusual, effervescent-type inclusions, though infrequent, bears a striking similarity to that reported in the giant quartz reef domain. Thus, the highlight of the present work is the convincing fluid inclusion evidence that genetically links the BG with the giant quartz reef system, although many cited discrepancies arise from the radiometric dates. We visualize the episodic release of silica-transporting fluid to the major fracture system (now occupied by the giant reef) from the BG, thus making the fluid in the two domains virtually indistinguishable. Full article

The greisens discussed in the present study are associated with the Homrit Akarem post-collisional granites, which are exposed near the western edge of the Egyptian Nubian Shield in the Southeastern Desert of Egypt. The Homrit Akarem granites intruded into Neoproterozoic country rocks, with sharp intrusive contacts. The marginal parts of the Homrit Akarem intrusion underwent extensive post-magmatic metasomatism, resulting in the formation of albitized granite and greisens. The Homrit Akarem greisens occur as veins and stockworks, which can be classified into four types: muscovite-rich, cassiterite-rich, topaz-rich, and beryl-rich greisens. Based on petrographic inspection, we identified ore minerals (cassiterite, beryl, topaz, muscovite, Nb-Ta oxides, tourmaline, fluorite, and corundum) in the greisens using electron probe microanalysis. The Homrit Akarem mineralized greisens were formed in a magmatic cupola above A-type magma, where fluid–rock interactions played a significant role in their formation. The accumulation of residual volatile-rich melt and exsolved fluids in the apical part of the magma chamber produced albitized granite, greisens, and quartz veins that intruded into the peripheries of the granitic intrusion and its surrounding country rocks. The variation in the mineralogy of the studied greisens indicates the diverse chemical composition of both the hydrothermal/magmatic fluids and the host granites. The simultaneous decrease in temperature and pressure is considered a crucial factor that controlled mineralization in the apical parts of the magma chamber. The occurrence of cassiterite, beryl, topaz, tourmaline, muscovite, and Nb-Ta oxides in the studied greisens suggests a potential polymetallic deposit of industrial minerals. Full article

This study investigates pegmatites with exceptionally rare mineralogical and chemical signatures, hosted by the 1.8 Ga peralkaline albite-enriched granite, which corresponds to the renowned Madeira Sn-Nb-Ta-F (REE, Th, U) deposit in Pitinga, Brazil. Four distinct pegmatite types are identified: border pegmatites, pegmatitic albite-enriched granite, miarolitic pegmatite, and pegmatite veins. The host rock itself has served as the source for the fluids that gave rise to all these pegmatites. Their mineral assemblages mirror the rare-metal-rich paragenesis of the host rock, including pyrochlore, cassiterite, riebeckite, polylithionite, zircon, thorite, xenotime, gagarinite-(Y), genthelvite, and cryolite. These pegmatites formed at the same crustal level as the host granite and record a progressive magmatic–hydrothermal evolution driven by various physicochemical processes, including tectonic decompressing, extreme fractionation, melt–melt immiscibility, and internal fluid exsolution. Border pegmatites crystallized early from a F-poor, K-Ca-Sr-Zr-Y-HREE-rich fluid exsolved during solidification of the pluton’s border and were emplaced in contraction fractures between the pluton and country rocks. Continued crystallization toward the pluton’s core produced a highly fractionated melt enriched in Sn, Nb, Ta, Rb, HREE, U, Th, and other HFSE, forming pegmatitic albite-enriched granite within centimetric fractures. A subsequent pressure quench—likely induced by reverse faulting—triggered the separation of a supercritical melt, further enriched in rare metals, which migrated into fractures and cavities to form amphibole-rich pegmatite veins and miarolitic pegmatites. A key process in this evolution was melt–melt immiscibility, which led to the partitioning of alkalis between two phases: a K-F-rich aluminosilicate melt (low in H₂O), enriched in Y, Li, Be, and Zn; and a Na-F-rich aqueous melt (low in SiO₂). These immiscible melts crystallized polylithionite-rich and cryolite-rich pegmatite veins, respectively. The magmatic–hydrothermal transition occurred independently in each pegmatite body upon H₂O saturation, with the hydrothermal fluid composition controlled by the local degree of melt fractionation. These highly F-rich exsolved fluids caused intense autometasomatic alteration and secondary mineralization. The exceptional F content (up to 35 wt.% F in pegmatite veins), played a central role in concentrating strategic and critical metals such as Nb, Ta, REEs (notably HREE), Li, and Be. These findings establish the Madeira system as a reference for rare-metal magmatic–hydrothermal evolution in peralkaline granites. Full article

In this article, we consider the roles of transcrustal magma- and fluid-conducting faults (TCMFCFs) in the formation of mineral deposits, showing the importance of deep sources of heat and hydrothermal solutions in the genesis and history of deposit formation. As a result of the impact on the lithosphere of mantle plumes rising along TCMFCFs, intense block deformations and tectonic movements are generated; rift systems, and volcanic–plutonic belts spatially combined with them, are formed; and intrusive bodies are introduced. These processes cause epithermal ore formation as a consequence of the impact of mantle plumes rising along TCMFCF to the lithosphere. At hydrocarbon fields, they play extremely important roles in conductive and convective heat, as well as in mass transfer to the area of hydrocarbon generation, determining the relationship between the processes of lithogenesis and tectogenesis, and activating the generation of hydrocarbons from oil and gas source rock. Detection of TCMFCFs was carried out using MMSS (the method of microseismic sounding) and MTSM (the magnetotelluric sounding method), in combination with other geological and geophysical data. Practical examples are provided for mineral deposits where subvertical transcrustal columns of increased permeability, traced to considerable depths, have been found; the nature of these unique structures is related to faults of pre-Paleozoic emplacement, which determined the fragmentation of the sub-crystalline structure of the Earth and later, while developing, inherited the conditions of volumetric fluid dynamics, where the residual forms of functioning of fluid-conducting thermohydrocolumns are granitoid batholiths and other magmatic bodies. Experimental modeling of deep processes allowed us to identify the quantum character of crystal structure interactions of minerals with “inert” gases under elevated thermobaric conditions. The roles of helium, nitrogen, and hydrogen in changing the physical properties of rocks, in accordance with their intrastructural diffusion, has been clarified; as a result of low-energy impact, stress fields are formed in the solid rock skeleton, the structures and textures of rocks are rearranged, and general porosity develops. As the pressure increases, energetic interactions intensify, leading to deformations, phase transitions, and the formation of chemical bonds under the conditions of an unstable geological environment, instability which grows with increasing gas saturation, pressure, and temperature. The processes of heat and mass transfer through TCMFCFs to the Earth’s surface occur in stages, accompanied by a release of energy that can manifest as explosions on the surface, in coal and ore mines, and during earthquakes and volcanic eruptions. Full article

The Aït Abdellah copper deposit in the Bou Azzer-El Graara inlier of the Moroccan Anti-Atlas provides key insights into structurally and lithologically controlled mineralization in Precambrian terranes. The deposit is hosted in feldspathic sandstones of the Tiddiline Group, which unconformably overlie the Bou Azzer ophiolite, and is spatially associated with a NE–SW-trending shear zone. This zone is characterized by mylonitic fabrics, calcite veining, and an extensive network of fractures, reflecting a two-stage deformation history involving early ductile shearing followed by brittle faulting and brecciation. These structural features enhanced rock permeability, enabling fluid flow and metal precipitation. Copper mineralization includes primary sulfides such as chalcopyrite, bornite, pyrite, chalcocite, digenite, and covellite, as well as supergene minerals like malachite, azurite, and chrysocolla. Sulfur isotope values (δ³⁴S = +5.9% to +22.8%) indicate a mixed sulfur source, likely derived from both ophiolitic rocks and volcano-sedimentary sequences. Carbon and oxygen isotope data suggest fluid interaction with marine carbonates and meteoric waters, potentially linked to post-Snowball Earth deglaciation processes. Fluid inclusion studies reveal homogenization temperatures ranging from 195 °C to 310 °C and salinities between 5.7 and 23.2 wt.% NaCl equivalent, supporting a model of fluid mixing between magmatic-hydrothermal and volcano-sedimentary sources. The paragenetic evolution of the deposit comprises three stages: (1) early hydrothermal precipitation of quartz, dolomite, sericite, pyrite, and early chalcopyrite and bornite; (2) a main mineralizing stage characterized by fracturing and deposition of bornite, chalcopyrite, and Ag-bearing sulfosalts; and (3) a late supergene phase with oxidation and secondary enrichment. The Aït Abdellah deposit is best classified as a shear zone-hosted copper system with a complex, multistage mineralization history. The integrated analysis of structural features, mineral assemblages, isotopic signatures, and fluid inclusion data reveals a dynamic interplay between deformation processes, hydrothermal alteration, and evolving fluid sources. Full article