Porphyry Copper Research Articles

Formation of giant copper deposits driven by rapid uplift and sudden depressurization

Abstract Porphyry Cu deposits (PCDs) in collisional orogens are new targets for modern mineral exploration. A series of post-collisional (Miocene; 22-12Ma) porphyry copper deposit (PCDs) with Cu reserve over 45 Mt have been discovered in the Gangdese magmatic belt, southern Tibet. These magmas derived from partial melting of sulfide-bearing Tibetan juvenile lower crust are fertile for porphyry Cu in many aspects, such as high oxidation state, and rich volatiles such as water, S, and Cl, but some of individual plutons ended up with economic concentrations. The fundamental question remains what accounts for the significant Cu endowments. We measured the igneous zircon water contents of ore-related and barren high Sr/Y magmas in the Gangdese belt, southern Tibet and found that magmas that produce giant PCDs have lower zircon water contents than barren and small-deposit related magmas. Combined with previous fluid inclusions, magmatic breccias, apatite geochemistry, and thermal histories, which demonstrated higher initial water content in causative porphyries such as giant deposits of Qulong and Jiama, we believe that the lower zircon water content may be attributed to these magmas experiencing of faster cooling and sudden depressurization of a large, primed, volatile-saturated or supersaturated mid-upper crustal magma chamber, which could lead to rapid and voluminous volatile exsolution and fluid discharge. These processes caused intense hydrothermal alteration and large ore deposition. In contrast, magmas that experienced slow cooling and deep emplacement would undergo steady state degassing and weak alteration. The variable intrusive and thermal histories across Gangdese reflects interplay between surface and lithospheric dynamics within the Himalaya—Tibet orogen. Our findings suggest the difference of zircon water content reflects the emplacement rate and depth of granitic body, and therefore may serve as an indicator for tectonics and potential for mineralization.

Porphyry copper formation driven by water-fluxed crustal melting during flat-slab subduction

AbstractThe prevailing view of the formation of porphyry copper deposits along convergent plate boundaries involves deep crustal differentiation of metal-bearing juvenile magmas derived from the mantle wedge above a subduction zone. However, many major porphyry districts formed during periods of flat-slab subduction when the mantle wedge would have been reduced or absent, leaving the source of the ore-forming magmas unclear. Here we use geochronology and thermobarometry to investigate deep crustal processes during the genesis of the Late Cretaceous–Palaeocene Laramide Porphyry Province in Arizona, which formed during flat-slab subduction of the Farallon Plate beneath North America. We show that the isotopic signatures of Laramide granitic rocks are consistent with a Proterozoic crustal source that was potentially pre-enriched in copper. This source underwent water-fluxed melting between 73 and 60 Ma, coincident with the peak of granitic magmatism (78–50 Ma), porphyry genesis (73–56 Ma) and flat-slab subduction (70–40 Ma). To explain the formation of the Laramide Porphyry Province, we propose that volatiles derived from the leading edge of the Farallon flat slab promoted melting of both mafic and felsic pre-enriched lower crust, without requiring extensive magmatic or metallogenic input from the mantle wedge. Other convergent plate boundaries with flat-slab regimes may undergo a similar mechanism of volatile-mediated lower-crustal melting.

Integrated remote sensing and geochemical studies for enhanced prospectivity mapping of porphyry copper deposits: a case study from the Pariz district, Urmia-Dokhtar metallogenic belt, southern Iran

Mapping hydrothermal alteration zones associated with porphyry copper deposits (PCDs) is crucial for identifying new exploration targets on a regional scale. Hydrothermal alteration indicator layers play a fundamental role in recognizing potential areas for PCDs, highlighting the need for precise delineation of these zones and their integration with geochemical and geological data to reduce uncertainty in mapping porphyry copper prospectivity. This study focuses on the Pariz district within the Urmia-Dokhtar Metallogenic Belt (UDMB) in southern Iran, a region known for its significant porphyry copper mineralization. First, logical operator algorithms (LOA) were applied to ASTER remote sensing data to map and distinguish argillic and phyllic alteration zones associated with PCDs. Subsequently, propylitic alteration zones associated with chlorite-epidote and propylitic alteration associated with calcite were also delineated, as were silica-rich hydrothermal alteration zones. Five evidence layers corresponding to these geologic features were generated and weighted with logistic functions, independent of expert judgment and without consideration of the spatial distribution of known mineral occurrences (KMOs). In addition, two layers of information were developed, including multivariate geochemical signatures and proximity to intrusive rocks. The geochemical analysis identified two significant factors associated with porphyry copper mineralization: Factor-I (Zn, Pb, Cu, Sn, B) and Factor-II (Mo, Cu). These factors contributed to a multivariate geochemical signature in addition to the alteration layers derived from remote sensing. Evaluation using prediction- area (P-A) plots and Normalized density index (ND) confirmed the effectiveness of all seven layers for mineral prospectivity mapping (MPM). Geometric average (GA), data-driven index overlay (IO), and deep autoencoder neural network (DEA) integrated these layers, with IO showing superior performance in identifying high potential zones, as indicated by higher prediction rates compared to other methods. Therefore, IO proves to be the most efficient approach for mapping the regional porphyry copper minerals in the Pariz district of the UDMB.

Recycled mantle source for porphyry mineralization: U[sbnd]Pb and Re[sbnd]Os geochronology, and S–Pb–Cu isotopic constraints from the Urumieh-Dokhtar magmatic arc, central Iran

The Urumieh−Dokhtar magmatic arc (UDMA) hosts some of the world-class porphyry copper deposits in Iran. Here, we present high-resolution geochronological and stable isotope data to gain insights into the timing and source of the metallogeny of Kahang porphyry Cu deposit. Zircon UPb data show crystallization age of ca. 15 Ma age for the host porphyry intrusion and ReOs geochronology yields 14.5 Ma from the molybdenite associated with the ores. Sulfur isotope values on the sulphide minerals range from −1.6 ‰ to + 2.1 ‰, indicating a magmatic source for sulfur. Lead isotopic compositions of the S-bearing minerals are akin to those of the intrusive rocks, suggesting that the metal was likely sourced from mantle reservoirs. We propose a model for the UDMA involving slab break-off during the maturity of arc magmatism from the syn- to post-collisional stages of orogenesis. The δ65Cu data trace a systematic change from the barren to the fertile magmas. We suggest that partial melting of the sub-continental lithospheric mantle that has previously been refertilized of Cu through time as the potential source for the formation of ore-bearing magmas.

Magmatic initial and saturated water thresholds determine copper endowments: Insights from apatite F-Cl-OH compositions

Magmatic volatiles (H2O, F, Cl), especially water, are critical in the formation of porphyry copper deposit, for its significance as a carrier for metals. However, accurately quantifying the water contents of deep ore-forming magma remain a challenge. Here, we used apatite and forward modelling methods to reconstruct magmatic water evolution histories, with special concern on the control of initial magmatic H2O contents and water saturation threshold to porphyry mineralization. Samples investigated include granitoid rocks and apatite from highly copper-mineralized and barren localities. Generally, our research suggested that both ore-related and ore-barren magma systems are hydrous, the modeled magmatic water contents vary significantly among systems whether mineralized or not, and the major difference lies in the threshold of water saturation (6.0 wt% for barren, and up to 10.0 wt% for highly mineralized). Combined with whole rock geochemistry data (high K2O and Sr/Y contents) and modeling result (high modeled water thresholds), we think the ore-related magmas are stored at deeper depth with higher water solubility. In conclusion, we propose that the level of magmatic water saturation plays a crucial role in the formation of porphyry copper systems. Fertile magma has higher water solubility to which deeper storage depth is a critical contributing factor, and can get significantly water enriched upon saturation.

Processes controlling magma fertility at buenavista del cobre porphyry copper deposit (cananea, méxico): A new petrogenetic model based on zircon u-pb dating and apatite geochemistry

The Buenavista del Cobre is a world-class porphyry Cu-Mo deposit located in the Cananea Mining District, northern Sonora, México. Using zircon U-Pb dating, we show that the Proterozoic Cananea Granite, unconformably overlain regionally by Paleozoic limestones hosting skarn deposits underlies the present-day pit. We also present new crystallization ages for host rocks of copper mineralization in the District, dating for the first time a volcanic rock of the Henrietta Formation at 186.8 ± 1.1/3.0 Ma and the El Torre Syenite at 176.3 ± 1.1/2.9 Ma. Zircon U-Pb dating of the different porphyritic bodies reveals that the magmatic activity at Buenavista del Cobre lasted at least 4 Myr, from 59.7 ± 0.5/1.1 Ma to 56.1 ± 0.2/0.9 Ma. The deposit is composed by several porphyry intrusions referred to as “ore-rich” and “ore-poor” based on their individual metal contributions, which provides the opportunity to study the origin and processes enhancing magma fertility in an individual deposit. Combining our new geochronological dataset with geochemistry of apatite from the different porphyries allows us to propose a new petrogenetic model for the Buenavista del Cobre deposit. As the apatite Eu and Ce anomalies overlap with no clear difference between the ore-rich and ore-poor intrusions, we propose that the magmatic oxidation states of the magmas were similar. However, differences in apatite REE signatures, as well as variations in apatite Sr compositions between the two groups suggest that fractional crystallization processes in the parental magma influence the fertility of the porphyries. Additionally, apatite Cl contents of ore-rich porphyry intrusions are higher (>0.4 wt%) than the ore-poor intrusions (<0.2 wt%), suggesting an important role of the initial Cl content of the magmas in the mineralization process. These observations give new insights on the petrogenetic processes at origin of porphyry magma fertility. We propose that the evolution of the parental melt by fractional crystallization of hydrous minerals (hornblende) at upper crustal levels induced low H2O content of the residual magma, resulting in the formation of ore-poor porphyries. In contrast, we suggest that fractionation of anhydrous minerals (plagioclase) increased the H2O content in the residual melt, leading to the formation of ore-rich porphyries. Our new data allow us to propose an original genetic model for the Buenavista del Cobre deposit, which involves two cycles of supply, cooling and partial crystallization. This contribution shows that petrogenetic processes controlling porphyry copper magmas fertility are recorded in the composition of apatite at the deposit scale and highlights the importance of considering apatite geochemistry as an exploration tool.

Substantial in situ Ti isotope variations in rutile record source and fluid evolution of porphyry copper mineralization systems

Titanium (Ti) and its stable isotopes have been widely used as tracers for magmatic processes. However, our understanding of Ti isotope behavior in magmatic-hydrothermal systems remains limited. Hence, the in situ Ti isotope composition (δ49Ti) of magmatic titanite and hydrothermal rutile associated with magnetite and chalcopyrite mineralization was determined for the first time in four well-characterized porphyry copper deposits in southern Tibet. The rutile formed through the alteration of primary Ti-rich minerals during fluid-rock interaction in the early high-temperature magnetite and later moderate-temperature chalcopyrite stages of mineralization. Hydrothermal rutile, altered from magmatic titanite, exhibits δ49Ti values similar to those of residual magmatic titanite. This suggests that hydrothermal rutile inherited the Ti isotope composition of magmatic titanite. The average δ49Ti values of rutile are negatively correlated with whole-rock εNd(t) and zircon εHf(t) data, and positively correlated with whole-rock (87Sr/86Sr)i values, which suggests that the initial Ti isotope compositions of hydrothermal rutile in porphyry copper deposits primarily reflect their source. Rutile from the Qulong deposit sometimes exhibits fractionation of δ49Ti at levels exceeding 0.5‰, displaying a negative correlation with Zr and FeO, which may be attributed to the formation of magnetite and rutile at an early potassic alteration stage. Isotopically light Ti is preferentially incorporated into magnetite and rutile. Thus, the rutile associated with sulfide mineralization that formed from the remaining fluids during a later stage of phyllic alteration is enriched in heavy δ49Ti. These findings contribute to the understanding of how rutile fractionates Ti isotopes in hydrothermal systems related to porphyry copper deposits. In local contexts, the substantial crystallization of magnetite, along with the preferential incorporation of isotopically light Ti during the early stages, leads to a decrease in oxygen fugacity within the ore-bearing fluid. This, in turn, facilitates the formation of sulfides during later stages. The results of this study demonstrate the efficacy of in situ Ti isotope analysis as a powerful tool for tracking fluid and metal sources, and can be used to help interpret ore precipitation throughout different stages of magmatic-to-hydrothermal ore-forming processes.

Element Migration of Mineralization-Alteration Zones and Its Geological Implication in the Beiya Porphyry–Skarn Deposit, Northwestern Yunnan, China

Porphyry and the associated skarn-type deposit is one of the most important types of ore deposits worldwide, which usually exhibit significant zoning of mineralization-alteration, but the research on element migration in these mineralization-alteration zones is relatively weak. The Beiya porphyry–skarn gold-polymetallic deposit is a super-large Cenozoic deposit located in the Sanjiang metallogenic belt, northwestern Yunnan, China. In this paper, through a detailed analysis of mineralization and alteration zoning and its element migration regularity, the findings are as follows: (1) Three types of hydrothermal alteration—porphyry alteration, contact alteration, and wall-rock alteration—are developed, and porphyry alteration includes potassic, phyllic, propylitic, and argillic alteration; (2) five types of mineralization—porphyry-type Cu–Au–(Mo), skarn-type Au–Fe–(Cu), hydrothermal vein-type Au–Fe, distal hydrothermal-type Pb-polymetallic, and oxidizing-leaching enriched-type Au—occur in a diversity of forms, which are dominantly controlled by structures and lithologies; (3) concentric-banded mineralization-alteration zones are exhibited centrally from the alkaline porphyry outward or upward, namely [porphyry alteration] potassic → phyllic → propylitic → argillic → [contact alteration] skarnitization–marbleization → [wall-rock alteration] marbleization–silicification–calcitization; (4) porphyry-type mineralization predominantly forms within potassic and phyllic zones, while skarn-type mineralization occurs in contact alteration zones, and proximal and distal hydrothermal (vein)-type mineralization are commonly distributed in marbleization–silicification–calcitization alteration zones; and (5) element migration analysis demonstrates a significantly lateral and vertical zoning in the metallogenic element association of Cu–Mo → Cu–Au → Au–Fe–Cu → Au–Fe → Pb–Zn–Au–Ag–Fe from alkaline porphyry outward to the wall-rock. The mineralization-alteration zoning model indicates the Beiya deposit has similar mineralization and alteration zone characteristics to the typical porphyry copper system; and element migration within mineralization-alteration zones provides new scientific information for understanding the metallogenic regularity and prospecting at Beiya, as well as the similar types of deposits in the Sanjiang metallogenic belt and elsewhere in the world.

Hydrothermal rutile chemistry and U-Pb age fingerprinting of the formation of the giant Nurkazgan porphyry Cu-Au deposit, Central Kazakhstan

The porphyry Cu-related intrusions commonly comprise multiple phases such as the large Nurkazgan porphyry Cu-Au deposit in Central Kazakhstan, hosted in the Karagandinsky dioritic to granitic intrusive complex. Here, SHRIMP and LA-ICP-MS zircon U-Pb dating on the multiple ore-bearing intrusions from this complex confirms a punctuated magmatic history distributed over 35 m.y., and marked by three episodic porphyry events rather than a single event, with the oldest event being the early granodiorite and quartz diorite porphyries at ca. 437–440 Ma, the second being the quartz diorite porphyry at 429.7 ± 2.1 Ma, and the last being the late granodiorite and quartz diorite porphyries at 402.8 ± 3.7 Ma and 402.0 ± 3.9 Ma, respectively. The mineralization is related to the two younger episodic intrusions of quartz diorite porphyry at ∼ 430 Ma and ∼ 402 Ma, respectively. SIMS U-Pb dating of hydrothermal, Cu-rich (up to 20.9 ppm) rutile from the breccia-type ores directly constrains the timing of porphyry mineralization at 428.9 ± 6.9 Ma, which is coincident with the emplacement age of the ∼ 430 Ma quartz diorite porphyry, and thus demonstrates this porphyry as a causative intrusion generating main-stage mineralization. This close genetic link is also supported by the chondrite-normalized REE patterns of rutile, which show remarkably similar light REE-enrichments and moderate negative Eu anomalies to those of the ∼ 430 Ma quartz diorite porphyry. A molybdenite sample obtained from the main-ore stage vein, however, has a Re-Os age of 418.6 ± 1.8 Ma, which is slightly younger than the U-Pb age determinations of rutile. This indicates that the Re-Os isotope system was disturbed by the second (post-ore) thermal event related to ∼ 402 Ma quartz diorite porphyry. In line with published data, this study suggests that the rutile U-Pb age in combination with its REE patterns can be a powerful tool to trace the causative porphyry. Moreover, the typical LREE-enriched REE patterns coupled with the high Cu anomalies, inherited from the causative porphyry and related exsolving fluids, can be as diagnostic proxies for distinguishing the porphyry Cu-related hydrothermal rutile from those formed in orogenic gold deposits. Based on these two geochemical discriminators and U-Pb ages, rutile can serve as unique fingerprints to help improve porphyry copper exploration in green field or covered terranes to complement detrital zircon fertility indicators.

Crustal magma oxidation state and endowments in porphyry copper deposits

Crustal magma oxidation state and endowments in porphyry copper deposits

A zircon case for super-wet arc magmas

Arc magmas have higher water contents (2-6 wt.% H2O) than magmas generated in other tectonic environments, with a growing body of evidence suggesting that some deep arc magmas may be ‘super-wet’ (>6 wt.% H2O). Here, we use thermodynamic modelling to show that the behaviour of zirconium during magmatic differentiation is strongly sensitive to melt water contents. We demonstrate that super-wet magmas crystallise zircon with low, homogeneous titanium concentrations (75th percentile <10 ppm) due to a decrease in zircon saturation temperatures with increasing melt H2O. We find that zircon titanium concentrations record a transition to super-wet magmatism in Central Chile immediately before the formation of the world’s largest porphyry copper deposit cluster at Río Blanco-Los Bronces. Broader analysis shows that low, homogeneous zircon titanium concentrations are present in many magmatic systems. Our study suggests that super-wet magmas are more common than previously envisaged and are fundamental to porphyry copper deposit mineralisation.

Paleotectonic setting of basaltoid volcano-plutonic belts with porphyry copper deposits

The article considers geotectonic position and geological features of basaltoid volcano-plutonic belts (VPBs) associated with porphyry copper and gold-copper deposits. Three types of the belts, the oceanic, perioceanic, and riftogenic ones, are distinguished among these VPBs. The oceanic and peri-oceanic belts were incorporated into the composition of ensimatic island arcs and formed at a late stage of their development, after inversion of the basaltoid troughs. The riftogenic belts appeared in island-arc oceanic settings at a late stage of filling the spreading zones. VPBs of the first two types with porphyry gold-copper deposits are located over the convergent boundaries of tectonic plates in an above-subduction position, while belts of the third type form extended linear zones within individual rift structures and contain smallscale porphyry copper objects with poor gold and molybdenum contents. As examples of the structures, the Sunda, Philippine archipelago, New British, Solomon, Alaska, and Antilles ensimatic island arcs and the Irendyk and Novoalekseevsky belts of rift zones of the Southern Urals are described. Volcanic-plutonic associations participating in the structure of these VPBs (including those productive for porphyry copper mineralization), as well as structural-lithological complexes of their basement, are characterized. It is noted that repeated magmatism manifestations during the long-term development of the ensimatic island arcs lead to appearance of several basaltoid VPBs with porphyry gold-copper deposits, while basaltoid belts with porphyry copper objects in the rift settings are formed only once.

Mineralization processes in the Bainaimiao Cu-Au deposit in Inner Mongolia, China: Constraints from geology, geochronology, and mineralogy

The Central Asian Orogenic Belt underwent complex tectonic processes and is one of the most intensely accretionary areas globally. Porphyry copper deposits within the belt were likely subjected to deformation during tectonic processes. The Bainaimiao Cu-Au deposit is a typical example of a deformed porphyry deposit whose formation processes include a porphyry emplacement (Event I), a greenschist facies metamorphism (Event II), and a brittle deformation (Event III). Geochronology and trace element geochemistry of zircon, volatiles of magmatic apatite, along with the assemblages, textures, abundances, and compositions of phyllosilicates from these three events were investigated to unveil the physicochemical conditions under which the key geological events relevant to the deposit formation took place. LA-ICP-MS zircon U-Pb dating shows that the granodiorite porphyry in the northern and southern zones formed at 447.4 ± 1.6 to 445.8 ± 3.6 Ma and 436.1 ± 3.8 to 434.1 ± 3.3 Ma, respectively. The granodiorite porphyry in the northern zone has higher oxygen fugacity and Clmelt content but similar Smelt and Fmelt contents compared to the granodiorite porphyry in the southern zone. Microscopic and mineralogic observations point to Event I to be of high plagioclase (22–67 vol%) and quartz (6–40 vol%) content with a range of hydrothermal minerals related to potassic, phyllic, and propylitic alterations. Event II features high amphibole (38–83 vol%) or epidote-chlorite (up to 77 vol%) content with minerals precipitating along the schistosity planes. Event III is characterized by wide veins (3–80 cm) and the highest quartz (61–65 vol%) and calcite (12–19 vol%) content. Geothermometry results show the temperature of potassic and phyllic alterations of Event I to be ∼622 °C and ∼288 °C, respectively. Based on geothermometry and P-T pseudosections, the temperatures of metamorphism and metallic precipitation of Event II were ∼271–634 °C and 297–328 °C, respectively. Both mechanical and chemical mobilization of metallic elements results in Cu mineralization during Event II. The metallic precipitation temperatures of Event III spanned from 297 to 328 °C according to chlorite geothermometry. The ratios of Fe3+/Fetotal and Mg/(Mg + Fetotal) of biotite, chlorite Fe/(Fe + Mg), and white K-mica composition show the mineralizing fluid of Event III to be the most oxidized while that of Event II is the most reduced, F-rich and features the lowest water/rock ratio. This study suggests that deformation processes can increase the Cu mineralization grade of the deformed porphyry deposits through mobilization and re-precipitation of metallic elements.

Deep Forest Modeling: An Interpretable Deep Learning Method for Mineral Prospectivity Mapping

AbstractAccurate mineral prediction is crucial for reducing costs and uncertainties in mineral discovery and extraction. The use of artificial intelligence and big data has advanced mineral prediction into intelligent forecasting. Machine learning methods have shown significant promise in enhancing outcomes. Currently, neural network‐based approaches dominate deep learning (DL), but they lack interpretability and have high modeling complexity, making them less effective for complex problems and time‐consuming. Deep Forest, an innovative DL paradigm, addresses these issues by dynamically adjusting complexity and providing importance assessments for predictive factors. This study focuses on the North American Cordillera, known for its rich geological data and potential for porphyry copper deposits (PCDs). Predictions are made using Deep Forest with factors like Euclidean distance between faults and magmatic rock, fault line density, gravity anomalies, and stream‐sediment geochemical data. Deep neural networks, random forest, convolutional neural networks, transformer model and graph convolutional networks are also used for comparison. Deep Forest shows high performance and can avoid the black box problem of DL without relying on other tools in DL, providing a new perspective for the development and application of other non‐neural network DL models for mineral prediction. Feature importance analysis shows that geological structure and magmatism significantly influence PCD prediction. Elevated levels of elements like Al, Co, and Cr in stream sediments help identify mineralization‐related alterations. These findings underscore Deep Forest's capability to accurately and efficiently guide mineral exploration, highlighting its potential as a promising approach for mineral prospecting.

Distribution of Co, Te, Se in the porphyry copper systems: A case study of the Tonglvshan deposit, Eastern China

Porphyry copper systems contain porphyry Cu, skarn, carbonate-replacement and epithermal deposits, and presently supply nearly all the Te and Se, and have the potential to produce Co as by-product in the future. However, few studies have investigated the distribution of Co, Te, and Se in the specific porphyry-skarn deposit. Detailed mineralogical and geochemical analyses were conducted to investigate the distribution of Co, Te, and Se across porphyry, skarn, and carbonate-replacement ore types in the Tonglvshan porphyry-skarn Cu-Fe-Au deposit, Eastern China. The early sulfide stage in three ore types is characterized by Co-bearing pyrite (Py1a, Co up to 1.3 wt%) + droplet-like tetradymite ± hessite ± cattierite. The texture transition from coarse-grained, pore-free to porous Py1a in porphyry and skarn type ores suggests a shift from stable physico-chemical conditions to gentle fluid boiling, resulting in the precipitation of Co-and Te-bearing minerals. In contrast, fine-grained euhedral Py1a in carbonate-replacement type ores implies rapid cooling from high-temperature fluid interaction with marble.The late sulfide stage, which only occurs in skarn and carbonate-replacement type ores, is characterized by Co-rich pyrite (Py2) + carrollite + hessite + Bi-sulfosalts. In skarn type ores, tetradymite-kawazulite solid solution (TKSS) + hessite + native Te + naumannite reflects intense boiling, leading to an increase in fO2 and pH that precipitates Py2b (Co up to 19.2 wt%) and carrollite, while Te and Se may precipitate through vapor phase condensation. Conversely, the presence of fine-grained carrollite, zoned Py2a, sphalerite, and galena in carbonate-replacement type ore suggests that rapid cooling and increasing pH, resulting from fluid mixing, played a significant role in the precipitation Co and Te. Furthermore, the porous texture resulting from coupled dissolution-reprecipitation (CDR) during the late sulfide stage also provided favorable conditions for the formation of micro-nano sized critical metal particles.

A hybrid framework for Detection of Multivariate porphyry Cu Signatures and Anomaly Enhancement: Incorporation of SFA, GMPI, and Grey Wolf Optimization

Geochemical data from stream sediment are commonly employed for regional scale mineral exploration, as they can be utilized to detect geochemical anomalies associated with mineralization processes. However, recognizing efficient multielement geochemical signatures related to target mineralization using stream sediment geochemical data can be challenging due to the intricate nature of mineralization events. To achieve this goal, this article proposes a combination of statistics, logistic functions and machine learning techniques. Initially, the staged factor analysis (SFA) approach was applied to the data to determine the geochemical footprints associated with porphyry copper mineralization in the Varzaghan area. Subsequently, the geochemical mineralization probability index (GMPI) was utilized to facilitate appropriate separation, more precise identification, and the transfer of data into a fuzzy space. By using a combination of SFA and GMPI, it was feasible to enhance the detection of geochemical halos and concealed anomalies. Ultimately, the output of these two approaches was subjected to an improved clustering technique known as GWO-K-means to detect geochemical anomalies. The findings indicated that there is a strong relationship between known mineral occurrences (KMOs) and the identified anomalous areas. The success rate curve demonstrated that the optimized model outperformed the K-means model, proposing that optimization can boost the accuracy in identifying geochemical targets. Overall, the outcomes of this study can be beneficial for proper planning of future exploration activities.

Features of the continental volcanic-plutonic belts of the Junggar-Balkhash fold system

Purpose. The study aims to investigate the formation composition and structural-formation zoning of the Late Paleozoic continental volcanic and volcano-sedimentary formations of the Junggar-Balkhash fold system (JBFS). It also seeks to define the geological-geophysical characteristics and metallogenic specialization of the volcanic-plutonic belts (VPB) in the region. Methods. The research utilizes data from detailed mapping and analysis of Late Paleozoic magmatites in JBFS over the past 10-40 years. Structural-formation zoning of the region was performed from an actualistic perspective, along with the formation typification of stratified and intrusive ore formations. The study of metallogenic specialization was conducted considering modern geophysical research methods. Findings. Two main volcanic-plutonic belts have been identified: the Carboniferous marginal-continental Tasty-Kusak-Kotyryasan-Altunemel Belt and the Carboniferous-Permian intracontinental Balkhash-Ili Belt, which together cover about 80% of the JBFS territory. The geological-geophysical characteristics and metallogenic specialization of these belts have been defined. In particular, the findings highlight significant prospects for epithermal gold-silver and copper-porphyry mineralization. Originality. For the first time, a structural-formation zoning of JBFS has been conducted, and the typification of volcanic-Plutonic Belts has been substantiated. Additionally, their metallogenic specialization has been determined, revealing patterns of localization for epithermal gold-silver and copper-porphyry deposits. Practical implications. The study’s results are of great importance for exploration geology, contributing to the improved efficiency of searching for ore deposits in the region, particularly epithermal gold-silver and copper-porphyry targets.

Molybdenum–copper–porphyry mineralization in the Pavlovich ore field

Molybdenum–copper–porphyry mineralization in the Pavlovich ore field

ПЕРВЫЕ СВЕДЕНИЯ О МЕДНОЙ МИНЕРАЛИЗАЦИИ РУДОПРОЯВЛЕНИЯ ШАРОМСКОЕ, ЦЕНТРАЛЬНАЯ КАМЧАТКА

The report provides new data on the mineralogy of the ores of the Sharomskoye copper ore occurrence, the Kirganik-Sharom ore zone in Central Kamchatka. Copper ores are confined to the central part of the submeridional massif of subalkaline metasomatites. Mineralization is disseminated, less often vein-disseminated in nature.The studied ore samples, collected during field works in 2023, are represented by silicified metasomatites with developed sulfide mineralization. Among the vein and accessory minerals are quartz, chlorite, barite and apatite. Ore minerals are represented by magnetite, chalcopyrite and bornite. Hematite and malachite are the most common supergene minerals, while cuprite and hydroxides of Fe and Cu are less common. The established chalcopyrite-bornite mineral association of the Sharomskoye ore occurrence is considered typical of other copper mineral prospects in central Kamchatka and is characteristic of porphyry copper deposits.

Effects of mining activities and municipal wastewaters on element accumulation and integrated biomarker responses of the European chub (Squalius cephalus)

This study aimed to determine concentrations of 29 elements in the gills and liver as well as biomarker response in gills, liver, and blood of European chub from Pek River (exposed to long-term mining activities), and to compare these findings with individuals from Ibar River (influenced by emission of treated municipal wastewater) and Kruščica reservoir (source of drinking water) using inductively-coupled plasma optical emission spectrometry (ICP-OES). The metal pollution index (MPI) was also calculated. Supporting analyses for the detection of the municipal wastewater presence at investigated localities included analyses of microbiological indicators (total coliforms and Escherichia coli) of faecal pollution. We have assessed biomarker responses from molecular to organism level using the condition index, comet assay, micronucleus test, oxidative stress parameters, histopathological alterations, and fluorescence spectroscopy parameters. Multibiomarker analysis was summarized by Integrated Biomarker Response v2 (IBRv2). Among these locations, Kruščica exhibited the lowest, whereas the Pek River displayed the highest values for both categories of indicator bacteria. Due to the porphyry copper ores mining, individuals from Pek River had several times higher Cu concentrations in both gills and liver compared to the other localities which was confirmed by biomarker responses and IBRv2 value. On the contrary, fish from Kruščica reservoir were the least affected by elemental pollution which is also confirmed by low MPI and IBRv2 values. Responses of biomarkers correspond to the elemental accumulation in the liver and gills of the Ibar River are positioned between the Pek River and Kruščica reservoir. Of all the biomarkers analyzed in this study, the condition index was the least sensitive. The results of this study showed that fluorescence spectroscopy may be a method for fast screening of structural changes in gills caused by the pollution burden.