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Can tax regimes shape the incentives of governments to engage in armed conflict? India’s Maoist belt contains a large share of the country’s most valuable mineral deposits. Indian mining royalties benefit the States, but they are set by the central government. States are largely responsible for counter-insurgency operations within their territory. Therefore, the royalty regime could shape the incentive of states to support counter-insurgency efforts. This paper exploits the introduction of a 10% ad valorem tax on iron ore that was responsible for a 10-fold increase in royalty collections by the affected State governments. In a panel of district-level violence outcomes between 2007 and 2013, we find that the royalty hike was followed by a significant intensification of violence in districts with iron ore deposits compared to other areas. We also show that the higher royalty rates are followed by an increase in illegal mining activity, suggesting that the control of mineral resources underpins the observed intensification in violence.

Introduction There has been limited research conducted on the identifications/methodological approaches of using plant species as indicators of the presence of economically, important mineral resources. Objectives This study set out to answer the following questions (1) Do specific plant species and species assemblages indicate the presence of mineral deposits? and (2) if yes, then what sort of ecological, experimental, and statistical procedures could be employed to identify such indicators? Methods Keeping in mind these questions, the vegetation of subtropical mineral mines sites in northern Pakistan were evaluated using Indicator Species Analysis (ISA), Canonical Correspondence Analysis (CCA) and Structural Equation Modeling (SEM). Results A total of 105 plant species belonging to 95 genera and 43 families were recorded from the three mining regions. CA and TWCA classified all the stations and plants into three major mining zones, corresponding to the presence of marble, coal, and chromite, based on Jaccard distance and Ward’s linkage methods. This comprehended the following indicator species: Ficus carica, Isodon rugosus and Ajuga parviflora (marble indicators); Olea ferruginea, Gymnosporia royleana and Dicliptera bupleuroides (coal indicators); and Acacia nilotica, Rhazya stricta and Aristida adscensionis (chromite indicators) based on calculated Indicator Values (IV). These indicators were reconfirmed by CCA and SEM analysis. Conclusion It was concluded that ISA is one of the best techniques for the identification/selection of plant indicator species, followed by reconfirmation via CCA and SEM analysis. In addition to establishing a robust approach to identifying plant indicator species, our results could have application in mineral prospecting and detection.

The Dawenkou Basin is a Cenozoic terrestrial fault basin in Shandong Province, East China, containing abundant mineral resources, especially gypsum. Recently a borehole was drilled in this basin unearthing the upper and middle members of the Dawenkou Formation. From the upper member, well-preserved ostracodes were discovered, which are entirely non-marine taxa including species of Eucypris, Caspiolla, Candona and Candoniella. Based on the new material, a new species Candona dawenkouensis n. sp. was erected. The ostracode assemblage biostratigraphically indicates an age of middle Eocene to Oligocene of the upper member of the Dawenkou Formation and the strata bearing mineral resources (mainly gypsum) of the middle member of the Dawenkou Formation is likely early Eocene.

Mineral resources exploration in the Kingdom of Saudi Arabia became an important target for the Saudi government. Nowadays, the economic vision of the country is to move away from oil-based country...

Energy is an integral part of the economic security of any state, and it is more complex, the lower the degree of provision with its mineral resources and the higher the number of the population living in the country. Being the undisputed world leaders in terms of population (1.4 billion people and 1.3 billion people), China and India are concerned about ensuring the energy security of their national economies. According to the latest forecasts formed by the International Energy Agency, by 2040, these two countries will become world leaders in terms of imports of mineral products (in this case: crude oil and natural gas). China is the world leader in exporting goods; India is implementing an economic and industrial policy to turn the country into a world manufacturing hub. In this regard, providing countries with energy resources is one of the most critical tasks. At the same time, a significant problem is a dependence on regular supplies of raw materials and world prices for energy carriers. Respectively, countries should pursue a policy of diversification of suppliers of mineral products. The subject of this study is the Republic of India and its position in the world energy markets; issues of energy security and energy policy are also highlighted.

The application of deep learning algorithms in mineral prospectivity mapping (MPM) is a hot topic in mineral exploration. However, few studies have focused on recurrent neural networks (RNNs) in terms of integrating different evidential layers to map mineral potential. In this study, a gated recurrent unit (GRU) model was employed for MPM using a case study on the Baguio District of Philippines. To generate sufficient training samples for GRU, data augmentation with geological constraints was employed. To explore the influence of different orders of evidence layers, as inputs of RNN, a total permutation of the evidence layers was built. Meanwhile, a nonlinear controlling function was used to capture the spatial relationships between known mineral deposits and geological controlling factors and assign the value for each pixel of evidence layers. The obtained results demonstrated the excellent performance of GRU in MPM. The delineated high-anomaly areas show close spatial relationships with known mineral deposits and therefore can provide significant clues for the next round of mineral exploration in the study area.

Mine waters at the Reefton orogenic gold mine (active from 2007 to 2016) in southern New Zealand contained dissolved arsenic (As) and antimony (Sb) up to 5 mg/L during production of a sulfide concentrate that included arsenopyrite (FeAsS) and stibnite (Sb2S3). Ferric oxyhydroxide adsorption extracted As down to As.

Historical mine and mineral deposit datasets are routinely used to inform quantitative mineral assessment models, but they also can contain a wealth of supplementary qualitative information that is generally underutilized. We present a workflow that uses correspondence analysis, an exploratory tool commonly applied to multivariate abundance data, to better utilize qualitative data in these historical datasets. The workflow involves extraction of qualitative information on ore mineralogy from a mineral deposit database, attaches those data to a target geological feature, and analyzes the underlying data structure with correspondence analysis and hierarchical clustering. The output of correspondence analysis is inversely weighted to the relative frequency of ore minerals, and therefore rare mineral species (i.e., those with unusually low frequencies) can disproportionately contribute to the total variance of the dataset. We present a novel technique for aggregating frequencies of rare mineral species that minimizes this effect. We apply this workflow to evaluate how ore mineral assemblages in former and active mines vary in spatial relation to silicic calderas in the southwestern United States. The most common ore mineral associations observed spatially and genetically associated to calderas include those related to polymetallic, base metal-rich systems and epithermal Au–Ag systems. Three other groups of mineralized calderas were identified, including: (1) Hg–Sb mineralized calderas in the northern Great Basin and western Nevada volcanic field; (2) calderas associated with elevated abundances of Mn oxides/hydroxides, fluorite, and Be-minerals, mostly in eastern Utah and New Mexico; and (3) calderas with numerous U ± F deposits, which are located in central Colorado, the eastern Great Basin and in northern Nevada. The latter three groups are associated with economically significant critical mineral resources, including the Li resources of the McDermitt complex and Be associated with the Spor Mountain on the margin of the Thomas caldera complex. We conclude that correspondence analysis is a promising technique that can enhance data exploration of the qualitative information held within mineral deposit datasets. Consequently, it could have numerous applications for mineral potential mapping, resource assessment projects, and characterization of mineral systems.

Timing of the major Baiyun gold deposit (~ 70 t Au) in the northeastern North China Craton is controversial. A textural and geochronological study of high-grade gold ores identifies three generations of xenotime (Xtm-1, Xtm-2 and Xtm-3), even in single grains. The oldest Xtm-1, in grain cores, is of metamorphic origin, with very high U and U/Th ratios, and hump-shaped, HREE-enriched patterns with maximum normalized values at Yb and large negative Eu anomalies. It is dated at 1856 ± 6 Ma, consistent with its crystallization during regional metamorphism related to cratonization. In contrast, 244 ± 2 Ma Xtm-2 overgrowths are of hydrothermal origin, having low U and U/Th ratios and hump-shaped, MREE-enriched patterns with maximum normalized values at Ho and negligible Eu anomalies. Xtm-2 records a previously unrecognized Middle Triassic hydrothermal episode. Xtm-3, in equilibrium with native gold-hosting pyrite and rutile, is also hydrothermal. The Xtm-3 domains have similar U, U/Th ratios, and MREE-enriched patterns to Xtm-2, but a younger crystallization age of 231 ± 1 Ma. Associated rutile grains that show close textural associations with auriferous pyrite and native gold have an in situ SIMS U–Pb an intercept age of 229 ± 4 Ma, consistent with that of Xtm-3. Collectively, these reliable ages indicate that gold mineralization at Baiyun occurred at ca. 230 Ma, predating the emplacement of granite intrusions by more than 3 million years. Both the Middle Triassic hydrothermal event (~244 Ma) and the Late Triassic gold mineralization event (~230 Ma) lie within the temporal window of collisional tectonics in the host orogen. In combination, the new geochronology and fluid-inclusion and geological data support Bayun’s classification as an orogenic gold deposit.

Due to high metal values and raised difficulties in finding superficial deposits, the exploration for mineral resources needs to reach greater depths. To achieve this objective, integrating ASTER and 3D inversion of aeromagnetic can be a useful tool in imaging deep magnetic mineralization hosting-structures. In this study, we present such integrated approach for deep mineral exploration in some promising zones of Gabal (G) Semna region, Eastern Desert (ED) of Egypt. Aeromagnetic data was used to delineate the structures and their relation to ore deposits and ASTER data was utilized for mapping lithological units and the hydrothermal zones. The 3D inversion was employed to imagine the depth and geometry of the magnetized ore bodies in the zones that identified by processing ASTER data. The 3D magnetic inversion revealed that mafic rocks and metavolcanics exhibit high-amplitude magnetic anomalies. High amplitude (positive) magnetic anomalies are joined with the large susceptibilities metavolcanics. Alteration zones in the mafic to basic bedrock and alongside major fault systems are high potential zones that revealed by ASTER image analysis. Aster and aeromagnetic data were used to map and alteration zones surface geology that can host mineralization and the 3D inversion was applied to outline the subsurface extent of these promising areas. This approach can be broadly used for deep mineral exploration in the Egyptian ED and identical areas around the world.

The Kurdistan Region in Iraq is located in the extreme northeastern part of the Arabian Plate which is in a collision since the Late Cretaceous with the Iranian Plate. Therefore, large ophiolite bodies have been thrust along the northeastern margins of Kurdistan Region; accordingly, different metallic mineral can be associated with igneous and metamorphic rocks at Penjween, Qalat Diza and Rawandouz vicinities, besides, radioactive minerals like uranium and thorium. Moreover, large and long thrust fault has developed along the northern and northeastern parts of the Kurdistan Region. Along the plane of this huge thrust fault, hydrothermal liquids have deposited different metallic minerals as showings, especially between Zakho and Amadiyah towns. We have presented and discussed the discipline of mineral investment in Kurdistan Region, the announced minerals’ blocks for investment by the Ministry of Natural Resources in the Kurdistan Regional Government, the encouraging factors and obstacles of investments. To fulfill the scope of this work, we have used the best available and updated data as acquired from different sources. The main obstacles which contributed to the backwardness and non-development of the mining industry in the Kurdistan Region can be summarized in the nonexistence of a valid and promising mineral investment law which can attract the big international mining companies to invest in the region, adding to the nonexistence of comprehensive, detailed and mineral exploration studies which can give confident figures of the mineral and ore reserves in the region. The non-availability of a specialized mining education institution which prepares mining expertise and mining engineers who can lead the progress in this regard could count as another hurdle.

The Fourth generation industrial age and 5G + intelligent communication in the "Fourth Paradigm of Science" in the 21st century provide a new opportunity for research on the relationship between mining development and environmental protection. This paper is based on the theory of metallogenic geodynamics background, metallogenic process and quantitative evaluation and chooses the Luanchuan district as a case study, using deep-level artificial intelligence mining and three/four-dimensional (3D/4D) multi-disciplinary, multi-parameter and multi-scale modeling technology platform of geoscience big data (including multi-dimensional and multi-scale geological, geophysical, geochemical, hyperspectral and highresolution remote sensing (multi-temporal) and real-time mining data), carrying out the construction of 3D geological model, metallogenic process model and quantitative exploration model from district to deposit scales and the quantitative prediction and evaluation of the regional Mo polymetallic mineral resources, the aim is to realize the dynamic evaluation of highprecision 3D geological (rock, structure, hydrology, soil, etc.) environment protection and comprehensive development and utilization of mineral resources in digital and wisdom mines, it provides scientific information for the sustainable development of mineral resources and mine environment in the study area. The research results are summarized as follows: (1) The geoscience big data related to mineral resource prediction and evaluation of district include mining data such as 3D geological modeling, geophysics interpretation, geochemistry, and remote sensing modeling, which are combined with GeoCube3.0 software. The optimization of deep targets and comprehensive evaluation of mineral resources in Luanchuan district (500 km2, 2.5 km deep) have been realized, including 6.5 million tons of Mo, 1.5 million tons of W, and 5 million tons of Pb-Zn-Ag. (2) The 3D geological modeling of geology, mineral deposit, and exploration targeting is related to the mine environment. The data of exploration and mining in the pits of Nannihu – Sandaozhuang – Shangfang deposits and the deep channels of Luotuoshan and Xigou deposits show a poor spatial correlation between the NW-trending porphyryskarn deposits and the ore bodies. The NE-trending faults are usually tensional or tensional-torsional structures formed in the post-metallogenic period, which is the migration pathway of hydrothermal fluid of the related Pb-Zn deposit. There is a risk of groundwater pollution in the high-altitude Pb-Zn mining zones, such as the Lengshui and Bailugou deposits controlled by NE-trending faults are developed outside of porphyry-skarn types of Mo (W) deposits in the Luanchuan area. (3) Construction of mineral resources and environmental assessment and decision-making in intelligent digital mines: 3D geological model is established in large mines and associated with ancient mining caves, pit, and deep roadway engineering in the mining areas to realize reasonable orientation and sustainable development of mining industry. The hyperspectral database is used to construct three-dimensional useful and harmful element models to realize the association of exploration, mining, and mineral processing mineralogy for the recovery of harmful elements (As, Sb, Hg, etc.). 0.5 m resolution Worldview2 images are used to identify the distribution of Fe in the wastewater and slag slurry of important tailings reservoirs, so as to protect surface runoff and soil pollution.

Geometallurgical modeling of the production benches is an attempt to estimate the geometallurgical variables of the different ore domains, which leads to a better understanding of the ore and its properties. Having geometallurgical variables results in a more accurate prediction of ore characteristics, an improved drilling and blasting operation, and better efficiency of the processing plant. In this research, the geometallurgical variables required for the geometallurgical modeling of the extraction benches are discussed. Then, the relations between Bond work index (BWi), as one of the most important geometallurgical variables and the primary grindability index, and rock geomechanical properties are investigated based on the previously published studies. The BWi is the main parameter for measuring the resistance to the grinding of ore minerals. It represents the energy required for processing (e.g., crushing, grinding) ore rocks in the beneficiation plant. As a real case study, BWi of a production bench in Sungun Copper Mine, located in East Azarbaijan province, Iran, was estimated. The rock’s geomechanical properties were measured using laboratory tests, including uniaxial compressive strength, Brazilian tensile strength, point load strength, and hardness. Then, BWi was estimated using the proposed formulas in the literature and the results of the rock’s geomechanical properties. The selected bench consists of three ore zones and two dyke domains. The laboratory tests revealed that the first ore zone has a slightly higher compressive strength than the other two zones, while the compressive strength of the waste rocks is larger than the ore domains. Using the proposed equations in the literature, the predicted values of the BWi for the samples in ore zones are in the range of 6.36 – 14.44 (kWh/t), and therefore this wide range must be considered when the short-term production schedule is planned. In addition, variations are observed in the samples within a specific zone and between the ore zones, demonstrating heterogeneity in the selected bench. Finally, wide-open results obtained by different equations show a necessity to perform a geometallurgical program specifically for the Sungun mine.

Pressure relief borehole is one of the most effective methods to treat coal burst in deep-buried coal seams. However, due to the large amount of randomly distributed fractures in the coal body and the varying stress environments in underground coal mines, there is no practical method to assess relief boreholes by far, which brings problems for borehole design and construction. This study focuses on the assessment of relief boreholes in a single driving entry wherein the impact of mining panels on relief boreholes is eliminated. A practical method, focusing on field monitoring of borehole deformation with a new device, is developed to evaluate the single driving entry’s relief boreholes. This method is applied to a Chinese coal mine. The application results showed that the convergence process of the boreholes showed a three-phase characteristic. Phase one involves the fastest deformation, reaching up to 8% in the first 3 to 4 days. Phase two lasts longer and converges more, reaching up to 30% in 4 months. Phase three stays balanced until the excavating face moves. The three-phase characteristic indicates that a large diameter of the borehole ensures relief efficiency because the borehole provides adequate space for deformation throughout its life span. In addition, it is verified that long boreholes and slow footage improve relief efficiency by providing adequate time for the boreholes to work. The application proposes that boreholes in the test coal mine need to be drilled larger and longer for optimization.

The Sonakhan greenstone belt in Central India is under-explored with respect to gold in spite of its similarity to auriferous greenstone belts in general, which prompted a prospectivity analysis. The workflow involved adoption of a conceptual mineral systems model, recognizing indicative spatial proxies, processing exploration datasets, generating evidence maps and integrating into GIS-based mineral prospectivity mapping. Available geological information such as key lithologic units and their contacts was combined with geochemical anomalies of selected pathfinder elements, geophysical data (aeromagnetic anomaly and K/Th ratio map) and satellite digital image data (ASTER and Landsat 7 ETM +), leading to generation of 17 evidential layers. The lack of a significant number of known mineral occurrences in the study area precludes the use of data-driven prospectivity modeling techniques. Therefore, knowledge-driven approaches such as binary and multiclass index overlay, fuzzy logic and fuzzy AHP (analytic hierarchy process) were adopted to integrate the evidential layers resulting in four prospectivity maps. The variation of cumulative prospectivity with respect to cumulative area in each model was used to determine threshold to produce binary prospectivity maps separating high and low prospectivity zones. An approach based on the unique conditions of the binary prospectivity maps was used to illustrate the combined results of different models. In order to quantify the intuitive uncertainty in exploration targeting that arose due to different model outputs, a modulated predictive model was generated taking the mean prospectivity values at each pixel. The pixels having mean values above 95th percentile were grouped and the area delineated as potential exploration targets for gold that comprises merely 5% of the study area. The estimated uncertainty and confidence values for each pixel were used in the risk analysis that returned 1.95% and 3.05% of the study area as low- and high-risk exploration targets, respectively.

This paper presents a methodology to integrate mineral resource uncertainty from scarce orebody sampling and material mixing uncertainty due to ore flow into the life-of-mine production scheduling ...

This work addresses the problem of geostatistical simulation of cross-correlated variables by factorization approaches in the case when the sampling pattern is unequal. A solution is presented, based on a Co-Gibbs sampler algorithm, by which the missing values can be imputed. In this algorithm, a heterotopic simple cokriging approach is introduced to take into account the cross-dependency of the undersampled variable with the secondary variable that is more available over the entire region. A real gold deposit is employed to test the algorithm. The imputation results are compared with other Gibbs sampler techniques for which simple cokriging and simple kriging are used. The results show that heterotopic simple cokriging outperforms the other two techniques. The imputed values are then employed for the purpose of resource estimation by using principal component analysis (PCA) as a factorization technique, and the output compared with traditional factorization approaches where the heterotopic part of the data is removed. Comparison of the results of these two techniques shows that the latter leads to substantial losses of important information in the case of an unequal sampling pattern, while the former is capable of reproducing better recovery functions.

The success of exploration geochemistry requires identification of multi-element geochemical signatures. It has been revealed that Zhongdian island arc zone is an important area with supersized or large Cu–polymetallic deposits. In this regard, we proposed a hybrid method to identify multi-element geochemical anomaly for Cu–polymetallic deposits based on staged factor analysis, improved fractal density and expected value function. In this study, two factors including Cu–Zn and Mo–Pb associations were recognized after four stages of factor analysis of stream sediment geochemical data from Zhongdian area, Yunnan, China. Then, an improved fractal density model was developed to reveal the geochemical distribution patterns of these factors by introducing the parameter Pc (a form of singularity index) based on "general fractal topography". The results demonstrate that the proposed model enhanced the anomaly-background structure of Cu geochemical distribution pattern, and effectively characterized the anisotropic scale-invariance of local singularities. Furthermore, the assessment of Cu anomaly uncertainty showed there were about 33% of the Cu occurrences in the low probability areas, indicating these areas based on the Cu anomaly remain uncertain for Cu–polymetallic deposits. Thus, to generate a stronger anomalous signature for Cu–polymetallic potential mapping, the expected value function was utilized for the integration of the two different geochemical signatures, and the fuzzy algebraic sum operator was used also for comparison purpose. The contrasting results demonstrated that the proposed method can increase the intensity of favorable anomalies, reduce the uncertainty and optimize the prospecting areas.

Mineral resources are fundamental to drive the economic growth in a modern society. Although these resources have extensively been crossed referenced as “finite,” their metal production has increased steadily over the decades. The concept of “peak oil” has been under extensive debate, whereas that of “peak minerals” of individual metals lacks in-depth studies. This study aimed to provide a brief account of the ultimate recoverable resources for copper (Cu), gold (Au), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn). We utilized grade tonnage curves to illustrate future resource availability against a decline in the metal ore grade. Furthermore, an environmental indicator was calculated based on the total material requirement (TMR) to evaluate the present and future trends. Consequently, a visible decline in the metal grade for Cu, Ni, Au, Pb, and Zn was observed, whereas the future ore grade for Fe was projected to decline gradually. Furthermore, we estimated that as ultimate recoverable reserves peak approaches, metals will be recoverable at lower grades. The TMR increased for all metals, thus, indicating potential vulnerability to the environment. The findings indicate that awareness on the declining metal grades, environmental impacts of metals, and future mineral supplies will increase; however, other factors that govern the dynamics of recoverability and availability of these metals will offset the peak of these resources.

The Paleogene upper Xiaganchaigou Formation (E32) is the most important source rock and reservoir in the Qaidam Basin. However, there are few studies on the processes of hydrocarbon accumulation in this formation; therefore, its hydrocarbon resource potential has not been estimated reasonably. This paper evaluates the hydrocarbon generation properties in light of an improved hydrocarbon generation and expulsion potential model. According to the geochemical characteristics of source rocks and the petrological features of reservoirs, the potentials of different resource types, including conventional oil, tight oil and shale oil, are quantified by combining the buoyancy-driven hydrocarbon accumulation depth (BHAD) and the lower limit for movable resource abundance. The results show that the source rocks are characterized by a large thickness (more than 1000 m), moderate organic matter content, high marginal maturity and a high conversion rate (50% hydrocarbons have been discharged before Ro = 1%), which provide sufficient oil sources for reservoir formation. Moreover, the reservoirs in the Qaidam Basin consist mainly of low-porosity and low-permeability tight carbonates (porosity of 4.7% and permeability less than 1 mD). The maximum hydrocarbon generation, expulsion, retention and movable retention intensities at present are 350 × 104 t/km2, 250 × 104 t/km2, 130 × 104 t/km2 and 125 × 104 t/km2, respectively. The thresholds of hydrocarbon generation, expulsion and BHAD were 0.46% Ro, 0.67% Ro and 0.7% Ro, respectively. Moreover, the dynamic evolution process of hydrocarbon accumulation was divided into three evolution stages, namely, (a) initial hydrocarbon accumulation, (b) conventional hydrocarbon reservoir and shale oil accumulation and (c) unconventional tight oil accumulation. The conventional oil, tight oil and movable shale oil resource potentials were 10.44 × 108 t, 51.9 × 108 t and 390 × 108 t, respectively. This study demonstrates the good resource prospects of E32 in the Qaidam Basin. A comprehensive workflow for unconventional petroleum resource potential evaluation is provided, and it has certain reference significance for other petroliferous basins, especially those in the early unconventional hydrocarbon exploration stage.

Made available in DSpace on 2022-04-28T19:45:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 During its 13 years of non-continuous operation, the Osamu Utsumi Mine has generated serious environmental impacts. This mining complex is now attempting to decommission this uranium mine to reduce its environmental liabilities. As part of a hydrogeological analysis of the old Osamu Utsumi Mine pit area, a geophysical investigation was carried out along each front of the mine pit using electrical resistivity tomography and a dipole–dipole array. The lithology described in each front, the physical access, and data from monitoring wells also contributed to the geophysical interpretation and, hence, the hydrogeological analysis. The field results and geochemical data from monitoring wells enabled us to distinguish areas where water was flowing through fractures in the massif and areas with more acidic water, with electrical resistivity values less than 15 Ω m. Geosciences and Exact Sciences Institute (IGCE) São Paulo State University (UNESP, 24-A Ave, 1515, Bela Vista Federal University of Paraná (UFPR), XV de Novembro Str, 1299, Downtown Geosciences and Exact Sciences Institute (IGCE) São Paulo State University (UNESP, 24-A Ave, 1515, Bela Vista

The article discusses a software and technological environment designed for storing, processing and providing results of regional geological-geophysical and geological surveying works on regional study of subsoil and reproduction of the mineral resource base of hydrocarbon raw materials. The article describes the user workplaces organized for collecting, processing and evaluation of materials on approved GEW projects and final material transmitting for further storing at the Federal State Budgetary Institution «Rosgeolfond». It describes the main functionality and user interface, communication with Unified Bank of Geological and Geophysical Information of VNIGNI (UDB VNIGNI). It also describes directions of further development.

El incremento de recursos minerales es fundamental en toda operación minera, para el caso de estudio se buscó identificar nuevos recursos minerales en niveles antiguos, donde se tiene información antigua de sondajes diamantinos que en muchos casos no cuenta con análisis por todos los elementos. Se clasifico la información por dominios, donde se buscó una correlación entre los elementos Cu, Au y Ag, realizando los análisis de regresión se obtuvo las ecuaciones para cada dominio y cada elemento. Luego de obtener los valores ausentes por regresión, se procedió a realizar las estimaciones de estos recursos minerales en los niveles antiguos y se realizó una validación por medio de la conciliación con planta. El resultado que se obtuvo fue de un factor de conciliación de 89% el cual se encuentra dentro de los valores aceptables, generando una disminución de costos respecto a la ejecución de nuevos sondajes diamantinos y una mejor utilización a la información histórica que se tiene del yacimiento.

The object of research is the technological processes of the development of deposits and the extraction of solid minerals by underground and open-pit methods. The improvement of technological processes is achieved through the use of existing original technical solutions, which are currently advisable to use in practice. The work is aimed at increasing the efficiency of explosive energy use, improving the technological processes of mining operations in coal mines and open pits of mining enterprises. In the course of the study, an analysis of technical literature on mining topics was used, a search for copyright certificates for inventions and patents on the same topic was carried out. There was a search for innovative solutions that are expedient to apply at the present time. In the course of the analysis, the work shows ideas, methods of coal mining, systems for the development of coal seams, methods of destruction of rocks, microbiological reclamation and other new technologies and devices. The most promising technologies have been proposed for in-depth study, implementation and use in appropriate mining and geological conditions. The proposed technologies, for various reasons, have not yet found wide practical application at mining enterprises. Due to the application of the proposed technical solutions and technologies in practice in the conditions of existing coal mines and open pits, significant economic, environmental and financial effects can be obtained. This study was carried out in order to bring to a wide circle of specialists technical solutions that can contribute to a significant improvement in the technology of mining solid minerals, both in underground and open-pit mining all over the world.

Understanding the geochemistry of waters produced during petroleum extraction is essential to informing the best treatment and reuse options, which can potentially be optimized for a given geologic basin. Here, we used the US Geological Survey’s National Produced Waters Geochemical Database (PWGD) to determine if major ion chemistry could be used to classify accurately a produced water sample to a given geologic basin based on similarities to a given training dataset. Two datasets were derived from the PWGD: one with seven features but more samples (PWGD7), and another with nine features but fewer samples (PWGD9). The seven-feature dataset, prior to randomly generating a training and testing (i.e., validation) dataset, had 58,541 samples, 20 basins, and was classified based on total dissolved solids (TDS), bicarbonate (HCO3), Ca, Na, Cl, Mg, and sulfate (SO4). The nine-feature dataset, prior to randomly splitting into a training and testing (i.e., validation) dataset, contained 33,271 samples, 19 basins, and was classified based on TDS, HCO3, Ca, Na, Cl, Mg, SO4, pH, and specific gravity. Three supervised machine learning algorithms—Random Forest, k-Nearest Neighbors, and Naïve Bayes—were used to develop multi-class classification models to predict a basin of origin for produced waters using major ion chemistry. After training, the models were tested on three different datasets: Validation7, Validation9, and one based on data absent from the PWGD. Prediction accuracies across the models ranged from 23.5 to 73.5% when tested on the two PWGD-based datasets. A model using the Random Forest algorithm predicted most accurately compared to all other models tested. The models generally predicted basin of origin more accurately on the PWGD7-based dataset than on the PWGD9-based dataset. An additional dataset, which contained data not in the PWGD, was used to test the most accurate model; results suggest that some basins may lack geochemical diversity or may not be well described, while others may be geochemically diverse or are well described. A compelling result of this work is that a produced water basin of origin can be determined using major ions alone and, therefore, deep basinal fluid compositions may not be as variable within a given basin as previously thought. Applications include predicting the geochemistry of produced fluid prior to drilling at different intervals and assigning historical produced water data to a producing basin.

The Xiadian orogenic deposit with ~ 100 t of gold resources, located in the Jiaodong Peninsula, Eastern China, shows an economically attractive gold mineralization that is spatially associated with the Zhaoping detachment fault. This study presents a combination of field investigation, 3D modeling, spatial analysis of models, and prospectivity modeling using a multi-layer perceptron deep neural network to understand the association between gold mineralization and structural deformation and to identify targets for deep exploration. The principal gold mineralization at Xiadian occurs as disseminated ore associated with strongly fractured rocks. Spatial analysis determined that gold mineralization is located primarily in convex segments (0–50 m) of the fault footwall within 150 m of the fault buffer where the dip is gentle (~ 35° to 55°). Sulfide vein ore with high Au grades is, by contrast, typically sited within steeply dipping fracture-fill distal to the Zhaoping detachment (150–250 m), consistently in areas with NE-strike and associated with steep segments of the detachment fault. The distribution of the orebodies is attributed to brittle–ductile deformation proximal to the detachment and distal brittle extension. Given the characteristics of syn-deformation mineralization and the stress regime (NW σ3, NE σ2, and vertical σ1), the NE-plunging ore shoots were interpreted as the result of auriferous fluid flow into oblique dilation zones formed by the coupled normal and dextral strike-slip movement of the Zhaoping fault. Six potential gold targets were identified sub-horizontal to, and NE-trending from, known orebodies. This study highlights the utility of 3D prospectivity modeling as a robust tool for understanding orogenic gold spatial distribution and related structural controls.

The relevance of the study is in the need to expand the mineral resource base of Russia. Eastern Transbaikalia is one of the oldest mining regions of the country. Barun- Shiveinskoe field is mercury-antimony-tungsten ore formations. For the region, there is an urgent need to search for and discover new ore deposits. For successful completion of such a task, the data are needed from a detailed study of already known ore deposits, which can be used to develop scientifically reasonable criteria for searching for ore deposits and forecasting mineralisation. Such data includes determination of sources of ore-bearing melts and conditions of formation of mercury-antimony-tungsten ore formation deposits. The aim of the study is to prove participation in ore formation of several ore-bearing sources with different characteristics based on the data of isotopic composition of oxygen of ore-bearing quartz and sulphur sulfides, as well as comparative analysis of elemental composition of quartz-wolframite ores of Barun-Shiveinskoe deposit with quartz-wolframite ores of tungsten deposits in Eastern Transbaikalia. Object of the study is Barun-Shiveinskoe tungsten deposit located in Eastern Transbaikalia. Methods. To determine the elemental composition of rocks, the X-ray fluorescence method and standard chemical analysis were used at the Geological Institute of the Siberian Branch of the Russian Academy of Sciences (GIN SB RAS, Ulan-Ude). Oxygen isotopic composition was determined at the analytical centre (GIN SO RAS, Ulan-Ude) using a MIR 10-30 laser heating system with a 100 Watt CO2 laser and a 10,6 μm wavelength in the infrared region, in the presence of the BrF5 reagent using the Z.D. Sharp method (1990). Mineral composition study was carried out in GIN SO RAS on the LEO-1430VP scanning electron microscope with the INCA Energy 350 energy dispersion spectrometer (Oxford Instruments) at an accelerating voltage of 20 kV, probe current is less than 0,5 nA, probe size is 0,1 µm. In the analysis mode, the spectral set time was 50 s. Isotope composition of sulphur sulfides study was carried out at the collective use centre for multi-element and isotope studies of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk). Results. The isotopic composition of oxygen in the fluid was determined in equilibrium with quartz of the productive stage at 210–150 °C, varying from 4,25 to 14,22 ‰, which corresponds to aqueous fluid of magmatic nature. The isotopic composition of sulfur cinnabar, the final ore stage of the deposit formation, corresponding to mantle values, has been established. A narrow interval of δ34S, ‰ CDT values for cinnabar sulphur from –3,5 to to –4,5 indicates a single source. For the first time, a rare cinnabaric minerals (metacinobarite, corderoite) formed in the oxidation zones of mercury deposits under low-temperature conditions were identified at the deposit. Their elemental composition was determined. In quartz-wolframite ores from tungsten deposits in Eastern Transbaikalia, including Barun-Shiveinskoe, a close correlation relation (r – 0,53–0,96) with a number of elements (As, Ta, Nb, Hf) was identified, indicating common sources of their formation. Ore formation at Barun-Shiveinskoe deposit was carried out from different levels of ore-bearing sources. Wolframites were formed from a crust source and mercury from a mantle one.

An increase of components production for the equipment intended for oil and gas production is a key factor for analyzing existing technological processes and searching for new technological solutions to improve the efficiency of the production process and the quality of components. The article presents a simulation model designed to determine the rational technological processing parameters for the production of the “Centralizer shell” part. The basis for optimizing the working cycle of a production line is synchronization based on the principle of proportionality, which involves equalizing the duration of all technological operations with the rhythm of the production line. Synchronization of technological operations on the production line is carried out by choosing rational cutting parameters for each technological transition (cutting speed, feedrate, number of working passes). The “Centralizer shell” part is made of titanium alloy VT16, which has high strength, corrosion resistance and ductility. For the part under consideration, the permissible values ​​of the cutting parameters were determined based on the calculation of the total processing error, as well as the frequency of replacement of the worn cutting tool. The simulation model described in the article made it possible to increase the efficiency of the production process due to the synchronization of technological operations and the search for rational technological parameters, as well as to improve the manufacturing quality of the “Centralizer shell” part by analyzing the processing error at various parameters of the technological process.

The Ledong area is a typical high temperature and high pressure area in the South China Sea's Yinggehai Basin. The geological structure of this basin is complex, with high formation temperature gradient and multiple formation pressure steps. Therefore, accurate evaluation of formation pressure is facing great difficulties. Based on geological and logging data, the genetic mechanism of abnormal high pressure in the Ledong area is as follows. Abnormal high pressure in the Yinggehai Formation and upper strata is caused primarily by under compaction, whereas abnormal high pressure in the Huangliu Formation and lower strata is caused primarily by hydrothermal pressurization and hydrocarbon generation. At the same time, according to the rock strength, mineral composition and rock physical parameters of the unloading mechanism layers in the Ledong area, the influence of effective stress, porosity and shale content on acoustic velocity was obtained by collecting field cores from the Ledong area and conducting rock acoustic testing experiments in laboratory. The acoustic velocity decreased exponentially with decreasing effective stress, and it had a linear relationship with porosity and the square root of shale content, according to the experimental results. Based on the principle of linear superposition, an improved Bowers unloading model for formation pressure evaluation was established. The original model was modified to overcome the shortcomings of the traditional Bowers unloading model, and the effects of effective stress, porosity and shale content on acoustic velocity were considered comprehensively. The improved Bowers unloading model was applied to evaluate the formation pressure of high temperature and high pressure wells in the Ledong area. The results showed that the improved Bowers unloading model had good applicability in the Ledong area, with average error less than 3% in formation pressure. This model will serve as a technical reference for determining formation pressure in the Yinggehai Basin's high temperature and high pressure region.

The article presents the results of geological exploration for diamonds, precious metals, and base metals, conducted in the Russian Federation in consistence with licenses granted based on the declarative principle, beginning from the moment this mechanism was introduced. Key aspects of changes in the legislative regulation of this mechanism are represented. The information on the planned and factual financing of these works, on the number of the issued licenses, and on the respective increase in the resources and reserves of precious metals is provided. Specific (unit) indicators of the mineral reserve increase and of the respective costs were proposed, based on which the effectiveness of geological exploration was determined for projects performed in administrative subjects of the Russian Federation in consistence with the licenses granted by the declarative principle. Problems in implementation of the mechanism were identified. Recommendations for elimination of these problems are proposed.

A classification of built-in (internal) separators of mass-exchange columns for use in separation of drops of liquid from gas flow (steam flow and gas-steam flow) is proposed. A critical survey of the most typical designs of separators is carried out.

The static and dynamic characteristics of a marine sandstone bottom-water heavy oil reservoir include low structural amplitude, small thickness, strong bottom water energy, high watercut rise speed, significant differences in the watercut change law of wells, etc. Due to the complexities of accurate description of the sweep range and ridge shape of high watercut production wells, the evaluation and prediction of the remaining oil distribution is problematic, as well as the feasibility of the adjustment wells. In this paper, we have studied the dynamic characteristics of the water ridge of horizontal production wells in marine sandstone bottom-water heavy oil reservoirs. First, based on the physical simulation experiments, we discuss the overall morphological characteristics of the water ridge after the bottom water rise and the changes caused by the influence of an interlayer, considering the effect of the horizontal production wells and natural water driving. Second, a new method is proposed for calculating the characteristic shape of the water ridge in the heavy oil reservoir in the presence of the bottom water. The new method can be used for quick and accurate calculations of a 3D water ridge shape under horizontal production wells in reservoirs, with or without interlayers. It can also facilitate the quantitative evaluation of the water ridge sweep range of production wells in the high watercut periods. The new method can be applied to predict the remaining oil distribution range and reserves and provide important technical background for development adjustment measures and potential tapping for this type of heavy oil reservoir.

Appreciable amount of copper mineralisation dominated by chalcopyrite along with incidence of uranium within the Mayurbhanj granite batholith in Kesharpur-Madansahi-Dudhiasol sector has been established through preliminary exploration (UNFC-G3). Chalcopyrite-pyrite-pyrrhotite assemblages along with minor pentlandite seems to be preferably controlled through secondary structural shear fabric and vein selvages along the contact zones of granite and country rocks viz. hornblende biotite schist and metabasics. Hydrothermal alteration is notably marked by potassic, propyllitic and phyllic zones besides wide chloritisation and silicification in close proximity and within mineralised zone. Three potential prospects of significant copper mineralisation in terms of thickness and grade have been brought out at Kesharpur, Madansahi and Dudhiasol. These prospects show a linear lensoidal synformal disposition of the ore body trending NE-SW in eastern part to E-W in central part and NW-SE in the western part with moderate to steep northerly dipping. Out of these three prospects, Madansahi is quite promising where thickness of copper lodes varying from 2.00 m to 18.35 m and grade varies from 0.20% Cu to 1.76% with maximum nickel concentration of up to 0.13% Occurrence of copper mineralisation along with nickel concentration and anomalous uranium values up to 0.045% U3O8 is a significant achievement in establishing polymetallic mineralisation and augmenting the mineral resources in eastern India.

A new inventory on onshore petroleum seeps and stains in Greenland has been released by the Geological Survey of Denmark and Greenland as a web-based GIS model on the Greenland Mineral Resources Portal: Petroleum Seeps and Stains in Greenland. Knowledge on oil and gas seeps, oil stains and solid bitumen occurrences provides key information on mineral and petroleum systems, especially in frontier basins. As the understanding of recent and previous migrations of fluids and gases is important for both mineral and petroleum explorations in Greenland, this new inventory has been developed to facilitate exploration and new activities. The classification includes the following types of occurrences: (1) oil seeps, (2) gas seeps, (3) mud diapirs, pingos and gas-rich springs, (4) oil stains in volcanics, carbonates and sandstones, (5) solid macroscopic bitumen and (6) fluid inclusions and other evidence of micro-seepage. The inventory comprises detailed information on localities, coordinates and sample numbers. It also includes descriptions of features and geology, references to data, reports and publications. All information is summarised in either a mineral or petroleum systems context. Petroleum seeps and stains have been reported from most Palaeozoic, Mesozoic and Cenozoic basins in Greenland where they add important information on petroleum systems, especially distribution and facies variation of source rocks, petroleum generation and later migration, accumulation, remigration, uplift and degradation. The inventory is designed to be updated with additional localities and descriptions and new organic geochemical data. This paper provides a general overview of classification, nomenclature, organisation and content of the inventory. We introduce the regional distribution of petroleum seeps and stains in Greenland and general interpretations in the context of mineral and petroleum systems.

The article considers the peculiarities in the geotectonic development and ore potential of geological structures in Southern Altai, Eastern Kazakhstan. The territory encompasses the southeastern flanks of the tectonic zones of Rudny Altai and Kalba of Greater Altai, which are part of the overall system of the Central Asian mobile belt. The spatial adjacency of geological and ore-bearing structures of different ages and composition is emphasized, which were subjected to intense metamorphic and hydrothermal–metasomatic alterations under the influence of the Dzungarian massif and Siberian Plate and subsequent thrust–strike-slip deformations. The iron ore, copper, polymetallic, gold, and rare metal deposits formed in various geodynamic settings are characterized. The ore-controlling factors and criteria for forecasting and prospecting for ore objects are noted.

An investigation was undertaken to predict the post-closure water chemistry of the Cortez Hills Underground Deep South Extension where the mine workings will be backfilled with cemented waste rock. The objective was to determine the potential effects of the tunnel water on adjacent groundwater once the groundwater table recovers, hydraulic conditions stabilize, and ambient groundwater flow is reestablished. The average background groundwater chemistry from three wells representing discharge to the tunnel area during closure, and the worst-case groundwater dissolution chemistry of tunnel floor/unconsolidated backfill, shotcrete (sprayed concrete), cemented backfill and country wallrock/cemented backfill reactions were used to calculate their contribution to the total mass loading during tunnel flooding. The volume of groundwater flow through the tunnel area was coupled with these releases to calculate a total tunnel water quality. All analytes met NV Division of Environmental Protection Profile I standards, except for As, Sb, and Pb, due to their naturally-elevated background groundwater levels (0.08, 0.014, and 0.03 mg/L, respectively). The PHREEQC geochemical code was used to determine the post-closure dissolved phase solutes that could migrate to adjacent groundwater. The dissolved tunnel water chemistry was predicted to be pH = 8.2, with an alkalinity of 124 mg/L CaCO3 and with all solutes meeting Profile I except for As (0.07 mg/L) and Sb (0.01 mg/L). The predicted water chemistry was dominated by the influent groundwater, which comprised ≈97% of the mass loading and was similar to two existing underground seeps.

Two geophysical tools were used to delineate the configuration of the Nubian sandstone aquifer in the study area. Three hundred magnetic points were measured and analyzed to evaluate the subsurface structural setting and to trace the basement relief, which control the aquifer’s geometry. The magnetic interpretations refer to dominant faults that strike in various directions, namely N–S, NE–SW, and NW–SE. The top of the basement complex was recorded at depths of 384–1286 m, and the aquifer thickness ranged from 299 to 1169 m. Thirty vertical electrical sounding points of AB/2 with depths ranging from 1.5 to 700 m were used to estimate the parameters of the Nubian sandstone aquifer. The geoelectrical data indicate that the area consists of 5 units; the first unit is composed of sand and gravel, the second unit of ferruginous sandstone, the third unit of clay, the fourth unit of dry sandstone, and the last unit of sandstone saturated with groundwater. The groundwater in the study area is freshwater of high quality usable for all purposes.

The traditional convolutional neural networks applied in mineral prospectivity mapping usually extract features from only one scale at each iteration, resulting in plain features. To combat this limitation, this study utilized a convolutional neural network based on GoogLeNet to predict prospectivity for gold deposits in the Fengxian study area, China. The GoogLeNet adopted four groups of convolution kernels to extract and integrate features from multiple scales, obtaining abundant and comprehensive features related to mineralization. According to a multi-source geoinformation analysis, we selected 11 exploration criteria, including three geological factors (NW-trending brittle-ductile faults, NE-trending brittle faults, and anticline axes) and eight geochemical exploration data layers (Au, Ag, As, Hg, Pb, Zn, Cu, and Sb). Then, we created predictor samples to train the models to mine evidential features. Following to a comprehensive analysis, we formed a fusion model of GoogLeNet for mineral prospectivity modeling. The results demonstrated that the fusion model achieved an optimized predictive accuracy of 93.1% and an area under curve of 0.968. This fusion model outperformed the other models with superior success rate and prediction area rate performances, capturing 72% of the known gold deposits in just 27.3% of the research area. The results indicate the effectiveness of GoogLeNet in mineral prospectivity mapping. Finally, we classified the Fengxian district into three areas according to their different mineral prospectivity. The high-prospectivity areas provide significant implications for further exploration of gold deposits in the study area.

This thematic issue is in memory of Thomas Kurtis Kyser who died tragically in 2017. Kurt’s contribution to our understanding of the geochemistry of uranium deposits and the application of stable and radiogenic isotope studies to uranium ore systems is incalculable. His research on uranium deposits included the world-class unconformity-related uranium deposits from Canada, Australia, and Russia, and several other major types of uranium deposits worldwide such as Na-metasomatic deposit of Kurupung (Guyana) and Valhalla (Australia), volcanic-hosted deposits of Peru (Macusani), and vein-type uranium deposits from Beaverlodge district (Canada). He was the first to develop methods to use secondary dispersion of pathfinder elements to vector towards deeply buried uranium ore systems. These new geochemical and isotopic approaches are still successfully applied today. Kurt has been a pioneer in applying stable isotopic systems to characterize the paleofluid events associated with ore systems and to distinguish between barren and mineralized fluid pathways. Kurt was a prolific author with over 400 publications and over a hundred articles on uranium deposits. Kurt wrote three short courses for the Mineralogical Association of Canada dedicated to uranium deposits: Fluids and Basin Evolution (2000), Recent and not-so-Recent Developments in Uranium Deposits and Implications for Exploration (2008, in partnership with SGA), and Geology and Geochemistry of Uranium and Thorium Deposits (2015). However, his true legacy is the large number of undergraduate and graduate students, post-docs, and researchers that he taught, supervised, and mentored; most of whom are now working in industry, academia, and government institutions across the globe. He will be missed.

Uranium is an environmentally hazardous element, and is commonly present at trace levels (2.4 μg/g for world coals) in coal deposits. However, selected coal deposits could be highly enriched in uranium. In this study, 15 coal samples were collected from Eastern Yunnan coal deposits, China, aiming to characterize the distribution and the occurrence of uranium in those coals. In studied samples, uranium content varied from 0.36 to 8.28 μg/g, with an average value of 3.76 μg/g. Generally, uranium content in coals from northern coal mines (3.02 ± 2.44 μg/g, n = 5) were lower than it in southern coal mines (4.13 ± 2.30 μg/g, n = 10). Uranium in coal samples showed no obvious correlation with total sulfur, whereas was positively correlated with ash yield. The results of sequential chemical extraction procedure confirm that organic-bound is the dominant occurrence of uranium. The slight enrichment of uranium in studied coals was probably attributed to sedimentation processes, hydrological conditions and tectonic structure of the coal deposits.

Incised valleys form excellent stratigraphic pinch-out traps. Traditional seismic data analysis techniques fail to predict quantitatively the porous and low-velocity sand-fills for incised valleys. The 3D quantitative seismic inverted porosity–velocity (3DQSIPV) analysis was applied in the Indus Basin, SW Pakistan. The reflection strength attribute better portrayed the reservoir sandstone and faults compared to seismic amplitude attribute. The sweetness-based continuous wavelet transform authenticated the development of the stratigraphic play. The 17 Hz amplitude delineated the non-porous seal and porous reservoirs of sand-filled incised valley and strand plain, and faults. The integrated model of seismic attributes categorizes the reservoir and seal constituents. The petrophysical modeling corroborated the gas-bearing “sweet-spots” within the stratigraphic-based dynamical system. The facies modeling predicted the for coarse-grained sandstone and fine-grained shales, depositional environments, fluctuations of sea level and their impacts on the overall development of stratigraphic plays. The predicted density and P-wave velocity for the sandstone-filled incised valley of the lowstand system tract were ~ 1.4–1.75 g/cc and ~ 3217–3802 m/s, respectively. The predicted density and P-wave velocity for the sealing shales facies of strand plain of transgressive system tract were ~ 1.9–2.1 g/cc and 2.55–2.7 g/cc and 3900–4700 m/s, respectively. The 3DQSIPV predicted > 25% porosity and ~ 3300 m/s velocity of reservoirs in the west. The eastern zones shows 0.90 for inverted velocity. This workflow may serve as an analogue for the remaining oil and gas fields of the Indus Basins of Pakistan and similar geological settings of divergent plate margins.

The genesis of the giant Ag-Cu-Pb-Zn polymetallic mineralization in the northern Lanping basin, Southwest China, remains controversial. To address the sources of metals, a systematic study on Hg isotope compositions was conducted for the Cu-dominated deposit at Baiyangping and the Pb-Zn-dominated deposits at Fulongchang and Liziping. The Cu deposit shows positive Δ199Hg signatures (0.14 ± 0.13‰), in contrast to the Δ199Hg of the Pb-Zn deposits (− 0.09 ± 0.06‰). As positive Δ199Hg values are commonly observed in marine sediments and the Lanping Triassic marine sedimentary rocks show exclusively positive Δ199Hg signals (0.03 ± 0.07‰), the Hg in Cu ores was mainly sourced from the Triassic strata. The negative Δ199Hg signals observed in the Pb-Zn deposits, typical of terrestrial Hg, agree roughly with those of the Jurassic to Paleocene terrestrial sedimentary rocks (− 0.05 ± 0.08 ‰), indicating that the terrestrial strata provided the Hg in Pb-Zn ores. Compared to the source rocks, the Cu deposit shows isotopically lighter Hg enrichments (δ202Hg = − 2.30 ± 0.35‰), possibly resulting from fractionations induced by Hg2+ sorption, organic complexation, and precipitation of Hg-bearing sulfides. The Pb-Zn deposits show comparable or slightly heavier δ202Hg (− 0.56 ± 0.48‰); moreover, δ202Hg values of late-stage sulfides are higher than early-stage δ202Hg values, suggesting that the δ202Hg variation was primarily caused by sulfide precipitation. Thus, Hg isotope data indicate that separate hydrothermal events resulted in Cu and Pb-Zn mineralization. More importantly, this study reveals the great potential of Hg isotopes to discriminate sedimentary sources of metals for low-temperature hydrothermal deposits.

The world-class McArthur River Zn-Pb-Ag deposit is the type example of stratiform sediment-hosted deposits found in the Proterozoic basins of northern Australia. However, the McArthur River deposit is enigmatic in that, aside from a few sub-economic deposits within the same camp, other deposits of this type have not been discovered regionally. Understanding the key components of McArthur River-type mineral systems and the regional distribution of these components is crucial to further discovery. The recent discovery of the similar but pyrite-dominated system at Rosie ~ 90 km north of the McArthur River Mine sheds new light on the formation of this deposit class and provides a counterpoint to compare and contrast with the high base metal endowment at McArthur River. Stratiform pyrite mineralization at Rosie is finely laminated and is affected by erosional sedimentary processes superficially indicating it formed during sedimentation to early diagenesis and at or near the sediment–water interface. The conventional ore horizon in the McArthur River camp is the HYC Pyritic Shale Member in the lower Barney Creek Formation (~ 1640 Ma) within sub-basin architecture. Rosie is contained within a similar sub-basin architecture, but it occurs in the upper Barney Creek Formation. The absence of mineralization in the lower Barney Creek Formation at Rosie is attributed in part to prohibitive tectono-sedimentary conditions during early sub-basin development. The HYC Pyritic Shale Member equivalent is relatively thin beneath the Rosie mineralization and is only weakly enriched in hydrothermal elements. Its deposition was abruptly superseded by infill of the sub-basin by a thick barren sequence of fine turbidites. The fine turbidites were a rapid phase of accommodation space fill that diluted brines entering the sediment pile and effectively precluded hydrothermal sulfide mineralization as well as low temperature alkali metasomatism. Permissible tectono-sedimentary conditions did not return until late in sub-basin development, and by this time, sub-basin geometry had broadened and shallowed, and the hydrothermal fluid had evolved. Rosie mineralization is subsequently poorly focused and base metal deficient. The observation that sedimentation rate may play a role in mineralization is a significant addition to the field of basin-hosted mineral systems.