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A geochemical study was conducted on the Touro deposit, which is situated within the Iberian Variscan Massif on the allochthonous terrain of the Galicia–Tras-os-Montes Zone. This study encompassed both mineralogical and geochemical analyses of the host rocks, with a particular focus on the high-grade Fornás metamorphic unit of the Órdenes Complex. The deposit is composed of massive and semi-massive sulfides, the host rocks are amphibolites and paragneisses, and the ore is hosted in garnet amphibolites and mineralized paragneisses. A microscopic study of thin sections and over 300 electron probe microanalyses on various minerals were conducted with the objective of geochemical characterization. Furthermore, a study of approximately 6000 samples processed by mining companies for multielement analyses of over 1350 drill cores was conducted to geochemically characterize the host and mineralized rocks for use as exploration guides. Additionally, five samples underwent Sm-Nd isotope analysis. The data from the Touro Cu (Zn-Co) deposit are consistent with its classification as a mafic–siliciclastic (Besshi-type) VMS deposit constructed in a back-arc environment during the Ordovician period. Following burial and high-grade metamorphism during the Middle Devonian period, these rocks were subsequently exposed during the later Variscan deformation phases, resulting in the formation of the Arinteiro antiform. [ABSTRACT FROM AUTHOR]

The Iberian Pyrite Belt (IPB) represents one of the largest districts of volcanogenic massive sulfide (VMS) deposits in the world, and is a critical source of base metals (Cu, Pb, and Zn) for Europe. Confirmed resources exceed 1700 Mt of massive sulfides with grades of around 1.2% Cu, 1% Pb, and 3% Zn as well as more than 300 Mt of stockwork-type copper mineralization. Significant resources of Sn, precious metals (Au and Ag), and critical metals (Co, Bi, Sb, In, and Se) have also been evaluated. The genesis of these deposits is related to a complex geological evolution during the late Devonian and Mississippian periods. The geological record of such evolution is represented by three main lithological units: Phyllite–Quartzite Group, the volcano–sedimentary Complex (VSC), and the so-called Culm Group. The sulfide deposits are located in the VSC, associated with felsic volcanic rocks or sedimentary rocks such as black shales. The massive sulfide deposits occur as tabular bodies and replacement masses associated with both volcanic and sedimentary rocks. Their mineralogical composition is relatively simple, dominated by pyrite, chalcopyrite, sphalerite, and galena. Their origin is related to three evolutionary stages at increasing temperatures, and a subsequent stage associated with the Variscan deformation. The present paper summarizes the latest developments in the IPB and revises research areas requiring further investigation. [ABSTRACT FROM AUTHOR]

Assimilation and prolonged suspension of crust-derived sulfide liquid in komatiites are essential to form Ni-rich mineralisation. Evaluating the spatial relationship between komatiite-hosted Ni mineralisation and crustal S sources may thus provide insights into mechanisms of transport, metal enrichment and deposition of assimilated sulfide liquid. This study applied facies analysis and S isotopes to sulfides in Ni-mineralised komatiites and stratigraphically underlying bimodal volcanic-volcaniclastic and sedimentary rocks, which formed during rifting in the Agnew-Wiluna Greenstone Belt, Western Australia. The results revealed a lateral variation from rift-distal sedimentary sulfides, through sulfidic BIF, to rift-proximal VMS-style sulfides, the latter of which was predominantly assimilated by komatiites. Both crustal and komatiite-hosted sulfides were overprinted by granite-related skarn alteration during later basin inversion. Spatial S isotopes correlation revealed that Ni mineralisation in komatiites predominantly formed < 5 km from their crustal S sources, excluding long lateral transport as the main metal enrichment mechanism. Rather, metal enrichment likely happened through multiple cycles of sulfide entrapment and entrainment in lava flow vortices that formed in the wake of topographic steps represented by syn-rift faults. These faults were the main loci for pre-existing crustal weaknesses, hydrothermal fluid circulation, and VMS-style sulfide deposition, which were subsequently utilised by komatiites for enhanced thermo-mechanical erosion and crustal sulfide assimilation. This study shows that proximity to the syn-rift faults was the dominant control on the formation of komatiite-hosted Ni–sulfide mineralisation, regardless of substrate lithology. The S isotope signatures of crustal sulfides may be used as a proxy to identify syn-rift faults in highly deformed terranes. [ABSTRACT FROM AUTHOR]

The mechanism of chip formation during machining depends on the type of (i) work material, (ii) tool material, (iii) machining parameters, (iv) tool geometry, etc. It is difficult to understand the mechanism of chip formation without performing experimentation. The present effort has been made to know the mechanism of chip formation during the machining of chromium–manganese austenitic stainless (AST) steel. The chip formation mechanism study for the present steel has been conducted by performing (i) mechanical testing for the work material, (ii) chip type study, (iii) optical microstructural study of the chip surface, and (iv) SEM observation for the chip surfaces. The present chromium–manganese stainless steel (austenitic) was dry-turned in a lathe. Three different experiments were conducted. The input process parameters were v (speed), f (feed), and DOC (depth of cut). The chip reduction coefficient (CRC) and the von Mises stress (VMS) were the output response parameters. The chip thicknesses were measured. The steel specimen was tested on the universal tensile testing machine. The chip reduction coefficients (CRCs) and the von Mises stress were experimentally determined. The undersides of the chips were examined under a light microscope. The chip's top and bottom surfaces were viewed by scanning electron microscopy (SEM). The strain-induced martensite (SIM) formed at the chip surface (under) during the machining at the lower experimental parameters. The surface (underside) of the chip was influenced by the dynamic recrystallization (DRX) and the dynamic precipitation (DP) during the machining at the higher experimental parameters. [ABSTRACT FROM AUTHOR]

The Hongtoushan Cu-Zn volcanogenic massive sulfide (VMS) deposit, located in the Hunbei granite–greenstone terrane of the North China Craton, has undergone a complex, multi-stage metallogenic evolution. The deposit comprises three main types of massive ores: Type-1 ores, characterized by a sulfide matrix enclosing granular quartz and dark mineral aggregates; Type-2 ores, distinguished by large pyrite and pyrrhotite porphyroblasts and a small amount of gangue minerals; and Type-3 ores, mainly distributed in the contact zone between the ore body and gneiss, featuring remobilized chalcopyrite and sphalerite filling the cracks of pyrite. The metallogenic process of the Hongtoushan deposit is divided into three main stages: (1) an early mineralization stage forming Type-1 massive ores; (2) a metamorphic recrystallization stage resulting in Type-2 massive ores with distinct textural features; and (3) a late-stage mineralization event producing Type-3 massive ores enriched in Cu, Zn, and other metals. This study integrates sulfur isotope, trace elements, and fluid inclusion data to constrain the sources of ore-forming materials, fluid evolution and metallogenic processes of the deposit. Sulfur isotope analyses of sulfide samples yield δ 34 S values ranging from −0.7 to 4.2 (mean: 1.8 ± 1.5, 1 σ), suggesting a predominant magmatic sulfur source with possible contributions from Archean seawater. Trace element analyses of pyrite grains from different ore types reveal a depletion of rare earth elements, Cu, and Zn in Type-2 massive ores due to metamorphic recrystallization, and a subsequent re-enrichment of these elements in Type-3 massive ores. Fluid inclusion studies allowed for identifying three types of ore-forming fluids: Type-1 (avg. T h : 222.9; salinity: 6.74 wt.% NaCl eqv.), Type-2 (avg. T h : 185.72; salinity: 16.56 wt.% NaCl eqv.), and Type-3 (avg. T h : 184.81; salinity: 16.22 wt.% NaCl eqv.), representing a complex evolution involving cooling, water–rock interaction and fluid mixing. This multi-disciplinary study reveals the interplay of magmatic, hydrothermal and metamorphic processes in the formation of the Hongtoushan VMS deposit, providing new insights into the fluid evolution and metallogenic mechanisms of similar deposits in ancient granite–greenstone terranes. [ABSTRACT FROM AUTHOR]

Volcanogenic massive sulfide (VMS) deposits are globally significant sources of metals. The Hongtoushan VMS deposit is the only large Archean Cu-Zn VMS deposit in the North China Craton, carrying substantial economic value. Significant deformation and metamorphism have made the tectonic setting of the Hongtoushan VMS deposit the subject of extensive debate. This study investigates the petrogenesis and chronology of the ore-bearing host rocks from the Hongtoushan Cu-Zn VMS deposit in the North China Craton. By utilizing whole-rock geochemical analyses and zircon dating, this research sheds light on the origin and evolution of the ore-bearing rocks within the deposit. The whole-rock geochemical analysis data indicate that the Hongtoushan ore-bearing rock series is mainly composed of amphibole plagioclase gneiss (basalt protolith) and biotite plagioclase gneiss (andesite and rhyolite protolith), suggesting a complete volcanic cycle from basic to medium-acidic volcanic rocks. The amphibole plagioclase gneiss has slight LREE enrichment patterns with unremarkable depletions of Nb, Ta, and Ti and belongs to contaminated ocean plateau basalt (OPB) in terms of composition, which is generally interpreted as being generated from the mantle plume head. Meanwhile, the biotite plagioclase gneiss has relatively steep LREE enrichment distribution patterns with remarkable negative Ta, Nb, and Ti anomalies and a wide range of Zr/Y ratios, indicating their classification as FI- and FII-type felsic rocks; they were likely formed through the fractional crystallization of basic magma combined with crustal assimilation. When combined with the zircon dating results, the ore-bearing host rocks of the Hongtoushan VMS deposit were generated via a continuous magmatic evolution process. The zircon dating of the host rocks indicates a formation age of between 2609 and 2503 Ma, with metamorphic events between 2540 and 2466 Ma, which is consistent with the 2.5 Ga-related global mantle plume event. Further research shows that the ore-bearing host rocks are more likely to have been formed in a mantle plume-related stretching environment, possibly a margin rift. [ABSTRACT FROM AUTHOR]

Cloud computing platform offers numerous applications and resources such as data storage, databases, and network building. However, efficient task scheduling is crucial for maximizing the overall execution time. In this study, workflows are used as datasets to compare scheduling algorithms, including Shortest Job First, First Come, First Served, (DVFS) and Energy Management Algorithms (EMA). To facilitate comparison, the number of virtual machines in the Visual Studio.Net framework environment is used for the implementation. The experimental findings indicate that increasing the number of virtual machines reduces Makespan. Moreover, the Energy Management Algorithm (EMA) outperforms Shortest Job First by 2.79% for the CyberShake process and surpasses the First Come, First Serve algorithm by 12.28%. Additionally, EMA produces 21.88% better results than both algorithms combined. For the Montage process, EMA performs 4.50% better than Shortest Job First and 25.75% superior to the First Come, First Serve policy. Finally, we ran simulations to determine the performance of the suggested mechanism and contrasted it with the widely used energy-efficient techniques. The simulation results demonstrate that the suggested structural design may successfully reduce the amount of data and give suitable scheduling to the cloud.

Predicting fishing effort distribution is crucial for guiding fisheries management in developing effective strategies and protecting marine ecosystems. This task requires a deep understanding of how various hydrological factors, such as water temperature, surface height, salinity, and currents influence fishing activities. However, there are significant challenges in designing the prediction model. Firstly, how hydrological factors affect fishing effort distributions remains unquantified. Secondly, the prediction model must effectively integrate the spatial and temporal dynamics of fishing behaviors, a task that shows analytical difficulties. In this study, we first quantify the correlation between hydrological factor fields and fishing effort distributions through spatiotemporal analysis. Building on the insights from this analysis, we develop a deep-learning model designed to forecast the daily distribution of fishing effort for the upcoming week. The proposed model incorporates residual networks to extract features from both the fishing effort distribution and the hydrological factor fields, thus addressing the spatial limits of fishing activity. It also employs Long Short-Term Memory (LSTM) networks to manage the temporal dynamics of fishing activity. Furthermore, an attention mechanism is included to capture the importance of various hydrological factors. We apply the approach to the VMS dataset from 1,899 trawling fishing vessels in the East China Sea from September 2015 to May 2017. The dataset from September 2015 to May 2016 is used for correlation analysis and training the prediction model, while the dataset from September 2016 to May 2017 is employed to evaluate the prediction accuracy. The prediction error ratio for each day of the upcoming week range is only 5.6% across all weeks from September 2016 to May 2017. HyFish, notable for its low prediction error ratio, will serve as a versatile tool in fisheries management for developing sustainable practices and in fisheries research for providing quantitative insights into fishing resource dynamics and assessing ecological risks related to fishing activities. [ABSTRACT FROM AUTHOR]

The aim of motorway networks is to ensure smooth, high volume road traffic. The problem of anomalies in the system has been a longstanding concern for researchers, and with the widespread use of motorway networks a series of studies have been published on the subject. Speed limitation is one of the most important tools of mitigating disturbances. This study is looking for a solution to the problem known as the "shock wave effect". The research is based on a simulation method in a PTV VISSIM environment. The software can be used to examine certain traffic conditions, and then apply dynamic speed limitation based on these conditions. The Built Environment Information Platform (BENIP) is based on the idea that the built environment, the traffic, and the flow of information between them are closely related. The relevance of the study lies in the fact that a point-based notification of speed limits can be used for vehicles - a technology that is available in most cases at the infrastructure level on motorways - thus, improving road capacity and traffic safety. [ABSTRACT FROM AUTHOR]

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The mechanism of chip formation during machining depends on the type of (i) work material, (ii) tool material, (iii) machining parameters, (iv) tool geometry, etc. It is difficult to understand the mechanism of chip formation without performing experimentation. The present effort has been made to know the mechanism of chip formation during the machining of chromium–manganese austenitic stainless (AST) steel. The chip formation mechanism study for the present steel has been conducted by performing (i) mechanical testing for the work material, (ii) chip type study, (iii) optical microstructural study of the chip surface, and (iv) SEM observation for the chip surfaces. The present chromium–manganese stainless steel (austenitic) was dry-turned in a lathe. Three different experiments were conducted. The input process parameters were v (speed), f (feed), and DOC (depth of cut). The chip reduction coefficient (CRC) and the von Mises stress (VMS) were the output response parameters. The chip thicknesses were measured. The steel specimen was tested on the universal tensile testing machine. The chip reduction coefficients (CRCs) and the von Mises stress were experimentally determined. The undersides of the chips were examined under a light microscope. The chip’s top and bottom surfaces were viewed by scanning electron microscopy (SEM). The strain-induced martensite (SIM) formed at the chip surface (under) during the machining at the lower experimental parameters. The surface (underside) of the chip was influenced by the dynamic recrystallization (DRX) and the dynamic precipitation (DP) during the machining at the higher experimental parameters.

Results of modern studies of the earth's crust based on the gravitational data of the GOCE satellite have been used for the first time in a comparative metallogenic analysis of the geodynamic settings of the formation of polymetallic deposits in the folded frame of the Siberian and East European platforms. It is shown that deposits of the sedimentary exhalative deposits (SEDEX) type are more often located in the earth's crust with the dominating development of the lower "basaltic" layer. Pyrite copper and lead–zinc volcanogenic massive sulfide (VMS) deposits, as well as some manifestations of the SEDEX type, occur in supra-subduction island-arc and accretionary settings in the crust with the dominating development of the middle "granitic" layer. Pb-Zn ores of the Mississippi Valley type (MVT) are localized in deep pericratonic sedimentary oil and gas basins on the shelf and continental slope, with no spatial relationship to the stratification of the earth's crust. The Ag polymetallic mineralization of Taimyr and the Western Verkhoyansk region are confined to deep pericratonic rift troughs on the passive continental margin. They have a similar ore-bearing environment and can be combined into a single silver polymetallic Taimyr–Western Verkhoyansk belt. The results confirm the prospects of Pb-Zn deposits in Central and Eastern Taimyr and also in the Saurey ore region (Polar Urals), indicating the need for their further research. [ABSTRACT FROM AUTHOR]

Increasing amounts of data are being generated every year. Sustainable computing systems have become capable of extracting and learning information from the underlying data. Edge and AI (artificial intelligence) are expanding into industrial systems requiring new computing and networking infrastructure. Due to this, SLA computing is becoming increasingly challenging to handle in these emerging cloud environments. The cloud is a service that provides virtual resources to users. Qualitative and quantitative findings in market-oriented approaches are one of the most common methods for managing virtual and physical machines in a network. When allocating services, price is an important factor to consider. In this study, we aim to determine the initial price of VMs while considering the dynamic pricing model in a competitive, sustainable computing system. Besides negotiation-based trading, a multifactor architecture is used for trading in the marketplace. Based on the simulation results, it was found that the performance could be improved by categorizing the VMs based on regression. According to the simulation results, the cloud market system provides a better service-level agreement (SLA) and response time when assigning virtual machines to the market. Based on the results, we found that using the regression method for categorizing the VMs to manage the market improved the SLA. [ABSTRACT FROM AUTHOR]

The petrography, mineralization, and geochemistry and isotope studies of sulfide ores were used to determine the genesis of the Naweoba and Bagh Volcanogenic Massive Sulfide (VMS) deposits. These deposits consist of minor stockwork, massive sulfide, and gossan zones. They are hosted by basaltic rocks in the Naweoba Block and Bagh Complex of Zhob Valley Ophiolites, respectively. The host rocks are strongly altered to chlorite and sericite. By using whole rock and pyrite in situ analyses, it is found that the Cu concentration is higher compared to Zn and Pb. Similarly, the primary mantle normalized data of Pb, Cu, Ag, Au, and Zn as well as the high Co/Ni ratios (> 1) in pyrite for both deposits indicate that these deposits have a mafic origin dominated by hydrothermal processes. The trace element signature in pyrite and chalcopyrite in these deposits suggests that mineralization formed at high to moderate temperatures. The δ34S values of pyrite (2.4–4.6‰) and chalcopyrite (2.7–5.7‰) indicate that hydrothermal fluids have derived sulfur largely from basaltic igneous rocks. The above signatures are all consistent with a Cyprus-type VMS ore deposits associated with ophiolites. Moreover, it was found that several trace elements (Ni, Co, Se, Zn, Pb, Sb, and As) show systematic variations in pyrite from Naweoba that are correlated to the stratigraphic depth and can be used as a proxy to separate deeper from shallower sulfide ores. [ABSTRACT FROM AUTHOR]

Albacore tuna (Thunnus alalunga) is one of the target species of tuna longline fishing, and waters near the Cook Islands are a vital albacore tuna fishing ground. Marine environmental data are usually presented with different spatial resolutions, which leads to different results in tuna fishery prediction. Study on the impact of different spatial resolutions on the prediction accuracy of albacore tuna fishery to select the best spatial resolution can contribute to better management of albacore tuna resources. The nominal catch per unit effort (CPUE) of albacore tuna is calculated according to vessel monitor system (VMS) data collected from Chinese distant-water fishery enterprises from January 1, 2017 to May 31, 2021. A total of 26 spatiotemporal and environmental factors, including temperature, salinity, dissolved oxygen of 0–300 m water layer, chlorophyll-a concentration in the sea surface, sea surface height, month, longitude, and latitude, were selected as variables. The temporal resolution of the variables was daily and the spatial resolutions were set to be 0.5° × 0.5°, 1° × 1°, 2° × 2°, and 5° × 5°. The relationship between the nominal CPUE and each individual factor was analyzed to remove the factors irrelavant to the nominal CPUE, together with a multicollinearity diagnosis on the factors to remove factors highly related to the other factors within the four spatial resolutions. The relationship models between CPUE and spatiotemporal and environmental factors by four spatial resolutions were established based on the long short-term memory (LSTM) neural network model. The mean absolute error (MAE) and root mean square error (RMSE) were used to analyze the fitness and accuracy of the models, and to determine the effects of different spatial resolutions on the prediction accuracy of the albacore tuna fishing ground. The results show the resolution of 1 ° × 1° can lead to the best prediction accuracy, with the MAE and RMSE being 0.0268 and 0.0452 respectively, followed by 0.5° × 0.5°, 2° × 2° and 5° × 5° with declining prediction accuracy. The results suggested that 1) albacore tuna fishing ground can be predicted by LSTM; 2) the VMS records the data in detail and can be used scientifically to calculate the CPUE; 3) correlation analysis, and multicollinearity diagnosis are necessary to improve the prediction accuracy of the model; 4) the spatial resolution should be 1 ° × 1 ° in the forecast of albacore tuna fishing ground in waters near the Cook Islands. [ABSTRACT FROM AUTHOR]

The Hongtoushan Cu-Zn volcanogenic massive sulfide (VMS) deposit, located in the Hunbei granite–greenstone terrane of the North China Craton, has undergone a complex, multi-stage metallogenic evolution. The deposit comprises three main types of massive ores: Type-1 ores, characterized by a sulfide matrix enclosing granular quartz and dark mineral aggregates; Type-2 ores, distinguished by large pyrite and pyrrhotite porphyroblasts and a small amount of gangue minerals; and Type-3 ores, mainly distributed in the contact zone between the ore body and gneiss, featuring remobilized chalcopyrite and sphalerite filling the cracks of pyrite. The metallogenic process of the Hongtoushan deposit is divided into three main stages: (1) an early mineralization stage forming Type-1 massive ores; (2) a metamorphic recrystallization stage resulting in Type-2 massive ores with distinct textural features; and (3) a late-stage mineralization event producing Type-3 massive ores enriched in Cu, Zn, and other metals. This study integrates sulfur isotope, trace elements, and fluid inclusion data to constrain the sources of ore-forming materials, fluid evolution and metallogenic processes of the deposit. Sulfur isotope analyses of sulfide samples yield δ34S values ranging from −0.7 to 4.2 (mean: 1.8 ± 1.5, 1σ), suggesting a predominant magmatic sulfur source with possible contributions from Archean seawater. Trace element analyses of pyrite grains from different ore types reveal a depletion of rare earth elements, Cu, and Zn in Type-2 massive ores due to metamorphic recrystallization, and a subsequent re-enrichment of these elements in Type-3 massive ores. Fluid inclusion studies allowed for identifying three types of ore-forming fluids: Type-1 (avg. Th: 222.9; salinity: 6.74 wt.% NaCl eqv.), Type-2 (avg. Th: 185.72; salinity: 16.56 wt.% NaCl eqv.), and Type-3 (avg. Th: 184.81; salinity: 16.22 wt.% NaCl eqv.), representing a complex evolution involving cooling, water–rock interaction and fluid mixing. This multi-disciplinary study reveals the interplay of magmatic, hydrothermal and metamorphic processes in the formation of the Hongtoushan VMS deposit, providing new insights into the fluid evolution and metallogenic mechanisms of similar deposits in ancient granite–greenstone terranes.

Containers have emerged recently as a cloud technology for improving and managing cloud resources. They improve resource sharing by allowing instances to run on top of the host’s operating system. Container-based virtualization runs and manages hosted instances via the host kernel. Resource sharing can cause resource contention. In addition, dependent jobs, which may be deployed across multiple hosts, require frequent communication, resulting in a high volume of network traffic and network contention. The majority of existing research focuses on load balancing, with no consideration for the fact that network contention also plays a significant role in container performance. In this research, we propose a Dependency-aware Scheduling algorithm (DAScheduler) that deploys jobs into containers while accounting for both load balancing and job dependencies. The experimental results show that DAScheduler reduces network traffic by more than half and balances the loads. In comparison to one of the existing state-of-the-art techniques, DAScheduler improves overall cloud performance. [ABSTRACT FROM AUTHOR]

Zhang, S.; Tang, F.; Fan, W.; Yang, S.; Zhu, W.; Zhang, H., and Cui, X., 2023. Analysis of hauling net hours for Gazami crab (Portunus trituberculatus) gillnets based on the Beidou vessel monitoring system (BDVMS). Journal of Coastal Research, 39(4), 663–674. Charlotte (North Carolina), ISSN 0749-0208. Gillnets are among the most widely used fishing gear in the world, and there are nearly 97 thousand gillnetters in China's offshore. With the decline of resource fisheries, the fishing quota has remained a topic of concern for the world's fishing nations. At the beginning of 2017, the Ministry of Agriculture and Rural Affairs of the People's Republic of China implemented the total management of marine fishery resources and began to launch the quota fishing experiment. The vessel monitoring system (VMS) provides a new data source for fisheries research. It is a new attempt to estimate fishing yield from VMS. Refined fishing intensity can be obtained through calculation of hauling time or net length. In China, the shipboard Beidou satellite navigation system terminal was installed on well-equipped fishing vessels. It sends vessel identification and location information at three minute intervals and with 10 m spatial resolution. In this paper, the speed threshold was used to consider the hauling duration of the net. The hauling nets' hours were calculated to estimate the catch rate with the hours. The speed thresholds of the 56 vessels were from 1.7 to 2.4 m/s. The hauling duration in hour of the vessels were distributed throughout eight fishing grounds in 2017. Hauling duration was divided into 0.01° × 0.01° grids based on coordinate locations. The average hauling duration of the nets was 1.7 h, and the maximum value was 41.5 h. There were approximately 514 thousand net hauling points, and the catch weight of the swimming crab (Portunus trituberculatus) was calculated to be approximately 4.7 million kg in 2017 based on the hauling duration data. [ABSTRACT FROM AUTHOR]

The Tushkanikhinskoye deposit is confined to the Devonian basalt-bearing rhyolite calcareous-siliceous-terrigenous formation, which is represented by sedimentary, volcano-sedimentary, sedimentary-volcanogenic, pyroclastic, volcanic rocks of felsic and basic composition, as well as their subvolcanic equivalents. Felsic volcanogenic rocks show signs of ignimbrites. Primary pyrite-polymetallic ores with an uneven distribution of the main sulfides: sphalerite, pyrite, galena, and chalcopyrite have been identified. The presence of collomorphic, framboidal and granoblastic pyrite in the ores, as well as the presence of sedimentary breccia ores with sulfides in clasts and matrix advocates for the hydrothermal-sedimentary origin of the ores. The ore bodies represent destroyed hydrothermal structures, so-called "ore hills".

This article discusses the general classification approaches and key features of different families of polymetallic deposits, with particular attention to the largest in Eurasia Ozernoe polymetallic deposit located in Western Transbaikalia and thoroughly explored 50 years ago. The main groups (or families) of polymetallic deposits in the English-language literature are identified by brief names: volcanogenic massive sulphide (VMS), sedimentary exhalative (SEDEX), and Mississippi Valley type (MVT). Within these three families of deposits, there are many additional types/subtypes, a large number of which are mostly due to the incompleteness and inconsistency of accumulated knowledge on the genesis of polymetallic deposits. Overall, all Pb–Zn(Ag,Cu) deposits—both those that are considered syngenetic, forming on and near the seafloor (VMS and SEDEX), and epigenetic low-temperature ones (MVT)—demonstrate a wide range of features that distinguish and bring together these families. This also applies to the types and subtypes of mineral deposits identified within them. One of the most complex objects for geological–genetic classification is the Ozernoe deposit studied by the authors, which, in terms of the nature of the host rocks, is intermediate between the end members of all three families: SEDEX, VMS and MVT. The deposit is localized in volcanic–carbonate–terrigenous rocks of the Cambrian Oldynda formation, but the age and stratigraphic affiliation of the ore-bearing series remain a matter of debate. The Ozernoe deposit is a combination of massive sulfide and siderite ore beds, ore breccia horizons, low-carbonate aleuropelite members, limestones, fine detrital tuffites, lavas, and tuffs. The sulfide bodies are confined to several stratigraphic levels, and the main productive unit thickness reaches 230 m. The thickness is comprised of 12 mineral lodes, a series of stratified ore bodies separated by gangue layers of sedimentary and volcaniclastic rocks. The primary ore minerals are pyrite, sphalerite, and galena, while the minor minerals include magnetite, chalcopyrite, marcasite, tetrahedrite, and arsenopyrite. There are two main theories regarding the origin of the ore: volcanogenic–sedimentary and hydrothermal–metasomatic. The hydrothermal–sedimentary theory remains the prevailing hypothesis, but there are many indications that epigenetic hydrothermal–metasomatic and dynamic metamorphic processes have contributed to the formation of the deposit. These include the appearance of sulfide–quartz and quartz–carbonate–sulfide veins and vein zones in fine-grained "layered" ores, with large crystalline sphalerite and galena; multiple signs of ore recrystallization, including the formation of pyrite porphyroblasts and arsenopyrite metacrystals; and the formation of solid pyrrhotite and pyrrhotite–magnetite ores with a lenticular-striped, gneissic structure. These observations suggest that different processes, both hydrothermal–sedimentary and metamorphogenetic–metasomatic, were involved in the formation of the Ozernoe deposit. In other words, primary hydrothermal–sedimentary ores were redeposited by late hydrothermal solutions. Nevertheless, many issues concerning the genesis of the Ozernoe deposit remain unresolved. [ABSTRACT FROM AUTHOR]

When fisheries managers cannot see who is fishing or where fishing occurs, their scope for management interventions is limited. This lack of transparency in spatial fishing activity is considered a key enabler of illegal fishing and overfishing and hinders managers and consumers who aim to achieve sustainable fisheries. Increasing transparency in vessel location tracking is gaining momentum as a promising way to improve management of global fisheries. However, the mechanisms through which transparency in vessel activity can improve management have not been carefully studied. This paper provides a conceptual overview of the potential for greater transparency, both in quantity of vessels tracked and availability of data, from vessel tracking to help achieve sustainable fisheries goals. We identify four pathways through which these data can improve fisheries management and the conditions that enable transparency to be an effective governance tool. We qualitatively examine the costs and benefits of alternative models of transparency, including a hypothetical, fully transparent system. We highlight how potential costs and benefits of greater transparency depend on both governance context and management goals, and identify opportunities for future research to address key information gaps. [ABSTRACT FROM AUTHOR]

Deep‐sea hydrothermal systems provide ideal conditions for prebiotic reactions and ancient metabolic pathways and, therefore, might have played a pivotal role in the emergence of life. To understand this role better, it is paramount to examine fundamental interactions between hydrothermal processes, non‐living matter, and microbial life in deep time. However, the distribution and diversity of microbial communities in ancient deep‐sea hydrothermal systems are still poorly constrained, so evolutionary, and ecological relationships remain unclear. One important reason is an insufficient understanding of the formation of diagnostic microbial biosignatures in such settings and their preservation through geological time. This contribution centers around microbial biosignatures in Precambrian deep‐sea hydrothermal sulfide deposits. Intending to provide a valuable resource for scientists from across the natural sciences whose research is concerned with the origins of life, we first introduce different types of biosignatures that can be preserved over geological timescales (rock fabrics and textures, microfossils, mineral precipitates, carbonaceous matter, trace metal, and isotope geochemical signatures). We then review selected reports of biosignatures from Precambrian deep‐sea hydrothermal sulfide deposits and discuss their geobiological significance. Our survey highlights that Precambrian hydrothermal sulfide deposits potentially encode valuable information on environmental conditions, the presence and nature of microbial life, and the complex interactions between fluids, micro‐organisms, and minerals. It further emphasizes that the geobiological interpretation of these records is challenging and requires the concerted application of analytical and experimental methods from various fields, including geology, mineralogy, geochemistry, and microbiology. Well‐orchestrated multidisciplinary studies allow us to understand the formation and preservation of microbial biosignatures in deep‐sea hydrothermal sulfide systems and thus help unravel the fundamental geobiology of ancient settings. This, in turn, is critical for reconstructing life's emergence and early evolution on Earth and the search for life elsewhere in the universe. [ABSTRACT FROM AUTHOR]

Different fisheries, even the same fishery, use different ways of quantifying fishing efforts such as the number of vessels, days, voyages, and hooks. In squid-jigging fisheries, fishing hours, fishing days, and the number of vessels are valid units for calculating the catch per unit effort (CPUE). A vessel monitoring system (VMS) provides vessel position data with high spatial and temporal resolution and offers the possibility to quantify the CPUE at a finer scale. Using the squid fishery in the equatorial waters of the eastern Pacific as a case study, the CPUE was evaluated and standardized based on VMS data. The drifting operating points of the squid fishing vessels were filtered by the speed threshold, solar radiation, and operating time setting methods, leading to the number of fishing hours per day, and the nominal CPUE was calculated by combining the catch data obtained from logbooks. Then, the generalized linear model (GLM) and generalized additive model (GAM) were applied to conduct CPUE standardization considering spatiotemporal factors and environmental variables including sea surface temperature (SST), sea surface salinity (SSS), sea surface height (SSH), and chlorophyll-a (Chl_a). The results showed that month, latitude, SST, SSH, and Chl-a all have a high significant effect on CPUE as demonstrated through the significance test conducted by GLM. The GAM including the significant factors was judged to be the best model according to the AIC guidelines. The latitude range for high CPUE in the fishery was 3°S~0°S, SST range 24~25 °C, SSH range 4~8 m, and Chl_a range 0.15~0.20 mg/m3. In addition, the nominal and standardized CPUEs were compared based on fishing hours and fishing days. The results indicated that the two types of CPUEs were highly related hence there was no significant difference. [ABSTRACT FROM AUTHOR]

The massive sulfide deposits (VMS) from Mănăilă are associated with the metamorphic formations of the Tulgheș Lithogroup from the Bucovinian Nappes of the Crystalline-Mesozoic Zone in the Eastern Carpathians, Romania. The following types of ore were identified: pyrite-polymetallic, pyrite copper, compact and precompact copper, and quartz-precompact copper. The polymetallic mineralization consists of pyrite, chalcopyrite, sphalerite, galena, and subordinately arsenopyrite and tennantite. The copper, especially the quartz-copper mineralizations, have a distinct mineralogical composition compared to the other metamorphosed mineralizations of the Tulgheș Lithogroup. These types of deposits from Mănăilă contain large amounts of bornite and chalcocite along with chalcopyrite. Tennantite is abundant and has up to a 3.57 wt.% of bismuth. Wittichenite was identified for the first time in the metamorphic mineralizations and mawsonite was identified as the first occurrence in Romania. An unnamed mineral with the formula: C u , F e 11 P b , A g S 7 was also identified, belonging to the sulfides group. The compact and precompact pyrite-rich ores, located in sericite ± quartzite schists and covered by rhyolitic metatuffs, are of hydrothermal-sedimentary type metamorphosed in the greenschist facies. The source of the quartz-copper mineralization would be the retromorphic or metasomatic hydrothermal solutions that circulated through major fractures. [ABSTRACT FROM AUTHOR]

Gahnite occurs in diverse rock types and metamorphosed mineral deposits. The gahnite geochemistry is being used as an exploration tool for zinc sulfide deposits. In the present study, the geochemistry of gahnite and associated minerals viz. sphalerite, garnet, sillimanite, staurolite, anthophyllite, biotite, ilmenite, and chlorite, and their petrography have been used in studying the genesis, metamorphic evolution, deposit characterization, and exploration significance of seven Palaeoproterozoic volcanogenic massive sulfides (VMS) deposits in the Betul belt in the Central Indian Tectonic Zone, India. Different textural types of gahnites are recognized in the Betul belt. Field investigations of textural and geochemical characteristics suggest that the gahnites were formed by multiple geological processes: desulfidation of sphalerite, breakdown of almandine garnet, and zincian staurolite, and chloritization of zincian biotite corresponding with regional metamorphism. The temperature conditions of gahnite formation are estimated to be ~600–650°C using empirical Ti in biotite thermometry. The elemental concentrations in gahnites vary from Zn/Fe ratio 2–4; Co 1–30 ppm; Ga 14–573 ppm and Mn 126–3422 ppm, indicating that bimodal volcanics and volcano‐sedimentary rocks as protolith. High Mn content in gahnite suggests an influx of magmatic‐hydrothermal fluid in the protolith. Variations of trace elements (Mg vs. Al/V, Ti vs. Co/Mn, Co vs. V/Ga, Mn vs. Zn/Fe) and high‐temperature of gahnite formation attest to sensu stricto VMS type mineralization in Betul belt, which is entirely different from SEDEX, Broken Hill‐type, and non‐sulfide deposits. Principal component analysis of trace elements shows the geochemical variations at a few deposits and reveals that gahnites were formed as a result of the competing effect of fS2‐fO2 and governed by bulk rock composition. [ABSTRACT FROM AUTHOR]

Introduction Monotherapy with progesterone for treatment of vasomotor symptoms (VMS) was more effective than placebo treatment of postmenopausal healthy women in a Canadian trial. The PROGEST-trial was initiated to fulfill FDA-approval criteria for the indication of treatment of postmenopausal VMS. Methods This prospective randomized, double-blind placebo-controlled clinical trial studied three doses of oral micronized progesterone (200 mg, 300 mg, 400 mg) and placebo for 12 weeks. Postmenopausal women with moderate to severe VMS (> 50 per week) were screened for one week for VMS frequency, then randomized to 200, 300 or 400 mg progesterone daily or placebo for a double-blinded trial of 12 weeks duration. Results 74 women were recruited in 12 study centers. 44 terminated the study as per protocol (PP). Moderate to severe hot flushes decreased by 7.4/d in the placebo arm, 7.7 VMS/d with 200 mg/d progesterone (P4), 8.3 VMS/d on 300 mg/d and 9.0 VMS/d on 400 mg/d P4, respectively by week 12. 32 treatment emergent adverse events were documented in 18 participants, mostly minor AEs. The only SAE was a syncope requiring hospitalization on the day after treatment initiation, leading to discontinuation of the drug. Discussion Baseline VMS frequency was much higher in the German than in the Canadian study and the course of the placebo group had a markedly stronger decrease in VMS-frequency during the PROGEST study (-7.4/d) than in the Canadian trial (-1.4/d). Trial populations differed by age, BMI, the number of women with natural menopause, and comorbidities, mainly hypertension. Conclusion Premature discontinuation of the trial due to insufficient subject accrual rate led to only 55 randomized participants for analysis, therefore the study results lack statistical power. Still, a slight dose-dependent improvement in VMS was seen for all doses, while AE frequency did not increase with progesterone dose., Competing Interests: Conflict of Interest/Interessenkonflikt VSK was Principal Investigator (LKP) of the PROGEST trial and mentor in the Besins program “Campus Gynäkologische Endokrinologie”., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)

The Svärdsjö Zn-Pb-Cu deposit is situated in the heavily mineralised Bergslagen lithotectonic unit of the Fennoscandian shield, south-central Sweden. Intense hydrothermal alteration followed by a strong overprint by deformation and metamorphism during the Svecokarelian orogeny complicate interpretation of the local geology. Integration of whole-rock lithogeochemical and petrographic methods has allowed the mainly dacitic volcanic host succession and effects of ore-related hydrothermal alteration to be characterised. Mineralisation is hosted by 2–15 m thick, commonly skarn-altered dolomitic marble interbeds. Zones of strong–intense hydrothermal chlorite-sericite alteration envelop the marble units, recording mass gains of Fe and Mg, as well as Na depletion. Minerals such as cordierite, anthophyllite and sillimanite formed in these rocks during regional metamorphism. Mineralisation via sub-seafloor replacement is suggested for the deposit based on alteration zoning and the irregular, stratabound, marble-hosted style of sulphide lenses. It is inferred that mineralisation formed via neutralisation of hot, acidic metalliferous fluids. Geochemically and lithologically distinct units adjacent to the mineralised zones can serve as marker units to aid further exploration in the area. Mass change calculations reveal that Fe and Mg enrichment, as well as Na depletion exhibit detectable changes extending up to 100 m from the mineralised lenses, providing exploration vectors. [ABSTRACT FROM AUTHOR]

ObjectiveThe aim of this study was to investigate the efficacy of polidocanol against venous malformations (VMs).MethodsStudies reporting the treatment of VMs using polidocanol (published until February 15, 2020) were reviewed in the Embase and PubMed databases. After excluding the same literature, part of the studies were excluded by reading the title, abstract, full text. Eleven studies (with 287 participants) that fulfilled the inclusion criteria were included. Systematic meta-analysis was performed using Reviews Manager 5.2, and a fixed-effects model was used to calculate the pooled effective rate of polidocanol against VMs and the 95% confidence intervals (CI).ResultsLesion reduction of more than 50% was considered effective. A total of 287 patients were treated, and treatment in 271 was considered effective. The efficacy of polidocanol was 0.89 (95% CI = 0.83–0.93). Heterogeneity among the studies was small (I2 = 0%, P = 0.47). T The funnel plot was roughly symmetric.ConclusionOur study suggested that polidocanol is effective in the treatment of VMs. VMs at different sites can be treated without serious complications. Therefore, we have reason to believe that polidocanol is a safe and an effective drug for VMs.

[Display omitted] • Three mineralization stages are identified in the De'erni deposit; • Sulfur isotope data indicate a magmatic fluid mixed with seawater. • Co occurs as siegenite and is hosted in pyrite. The De'erni ultramafic-hosted volcanogenic massive sulfide deposit is a large Cu-Zn-Co deposit, located in the East Kunlun Orogenic Belt, and contains 0.57 Mt Cu, 0.16 Mt Zn, 0.03 Mt Co with a 0.09 % Co average ore grade. However, cobalt occurrence and the mechanism for its enrichment are unclear. This study investigated mineralogical characteristics using the TESCAN Integrated Mineral Analyzer (TIMA), Electron Probe Microanalysis (EPMA) analyses, Laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) analyses, and in situ sulfur isotopic analysis of minerals from different stages of ores in the De'erni deposit to understand Co mineralization. Three mineralization stages were recognized, and three types of pyrite were identified: Py1, Py2, and Py3 in the De'erni deposit. Cobalt occurs as siegenite, and a significant amount of Co is found in pyrite. The EPMA results show that the highest Co content is 0.40 wt% (0.02–0.40 wt%). The LA-ICP-MS trace element data show that Py1 is enriched in Co (208–5082 ppm), Ni (13.50–836 ppm, average 212 ppm), Py2 contains 11.07–322 ppm (average 94.45 ppm) Co, Py3 has Co contents of 0.68–31.90 ppm (average 5.79 ppm). The δ34S values of Py1, Py2, and Py3 range from 7.2 to 10.8 ‰, 4.6 to 6.7 ‰, 0.6 to 1.9 ‰, respectively, suggesting that the sulfur source originated from seawater-mixed magma fluids. Py1 occurs as euhedral-subhedral grains and displays oscillatory zoning, indicating a relatively unstable environment. Concentrations of Co, Ni, and As are highest in early-stage pyrite, whereas Se and Ag content gradually increased from Py1 to Py2 to Py3. The trace element data and mineral paragenesis indicate that the temperature and sulfur fugacity gradually decreased from stage 1 to 3. Furthermore, the first stage fluid is rich in Co and Ni, and the third stage fluid is rich in Ag and Se with Co and Ni depletion. These findings offer crucial insights into the De'erni deposit Co mineralization processes and evolution. [ABSTRACT FROM AUTHOR]

Indium (In) is a critical metal used in the photovoltaic and semiconductor industries, which have exhibited extraordinary growth in demand. Indium is produced as a by-product of mining from different ore deposits (e.g., epithermal, sediment-hosted, and skarn). Volcanogenic massive sulfide (VMS) deposits are an important source of In; however, the mechanism of In enrichment is not fully understood. Here, we combine mineralogy with in situ trace element and S-Pb isotope geochemistry to reveal the enrichment of indium in the Ashele VMS Cu-Zn deposit (1.08 Mt. Cu, 0.43 Mt. Zn) located in Altay, NW China. The Ashele deposit is hosted in the metamorphosed Devonian felsic-bimodal volcanic rocks. This deposit consists of seafloor hydrothermal, metamorphic hydrothermal, and supergene stages. The seafloor hydrothermal stage comprises macro-scale Cu-rich bands (chalcopyrite, pyrite, and minor sphalerite) and Zn-rich bands (sphalerite, pyrite, and minor chalcopyrite). Indium is mainly hosted by chalcopyrite (mean 178 ppm) and sphalerite (mean 214 ppm) and occurs in the lattice. Mineral assemblages and trace element geochemistry suggest that the Cu-rich bands were deposited under high temperatures (> 300–350 °C) and sulfur fugacity (−7.2 to −4.9), whereas the Zn-rich bands were formed under lower temperatures (180–220 °C) and sulfur fugacity (−15.7 to −11.5). The interlayered Cu-rich and Zn-rich bands may reflect the oscillating temperature and sulfur fugacity variations. In situ S isotopic compositions of sulfides cluster within two ranges: 1–3 ‰ and 3–6 ‰, suggesting two endmembers: volcanic origin and reduced seawater sulfate. Pb isotopic ratios are similar to those of the host volcanic rocks, indicating that the metals may be derived from the felsic volcanic system. During metamorphism, the indium may be retained, but Cu contents of sphalerite become more homogeneous. Most In-rich VMS deposits worldwide are hosted by the felsic-dominant system in island arc and back-arc settings. These tectonic settings are conducive to the production of felsic volcanic systems, which are more likely to contain In mineralization. This study highlights the enrichment mechanism of indium in VMS deposits and suggests that the South Altay could become an important source of In. • Ashele is an In-rich VMS deposit. • Metamorphic influence on the seafloor hydrothermal indium mineralization may be limited. • Felsic-dominant system in island arc and back-arc settings profits In-rich VMS deposits. [ABSTRACT FROM AUTHOR]

Dimethylsilanediol (DMSD) is the common degradation product of ubiquitous polydimethylsiloxane (PDMS) and volatile methylsiloxanes (VMS) in water and soil. Given the high solubility of DMSD in water, the further degradation of DMSD in this compartment is of particular importance. While DMSD appears relatively resistant to degradation in standard hydrolysis or biodegradation studies, it may degrade by indirect photolysis in surface waters through oxidation by hydroxyl radicals. The formation of hydroxyl radicals is governed by nitrate ions or other promoters in the presence of sunlight. In this study, we investigated the impact of nitrate ions on the oxidative decomposition of DMSD in water under simulated solar light. When exposed to solar light, DMSD can degrade all the way to the natural, mineralized substances, namely carbon dioxide (in the form of carbonic acid) and silicic acid, via the intermediate methylsilanetriol (MST). [Display omitted] • In situ formation of hydroxyl radicals in the presence of nitrate ion under simulated solar light. • Effects of nitrate ion concentration and initial DMSD concentration on indirect photolysis of DMSD in water. • Degradation mechanisms based on intermediate species and mineralized products. [ABSTRACT FROM AUTHOR]

The Paleoproterozoic Metsämonttu Zn–Pb–Cu–Ag–Au deposit (1.5 Mt at 3.5 wt% Zn, 0.8 wt% Pb, 0.3 wt% Cu, 13.2 wt% S, 25 g/t Ag, and 1.4 g/t Au, production 1952–1974) is the largest past-producing mine in the Aijala–Orijärvi area (Orijärvi formation, Aijala member) within the Uusimaa belt, southern Finland. The Aijala member is characterized by 1.9–1.88 Ga felsic-dominated volcanic-sedimentary supracrustal rocks with intercalated sedimentary carbonates and iron formations. The area is underexplored, and little deposit-scale research has been carried out, despite the lateral continuum to the world-class ore district of Bergslagen in south-central Sweden. To better understand the Metsämonttu VMS-related alteration system, we reassessed the previously described metamorphic mineral assemblages and their protolith rock compositions by using mobile and immobile element geochemistry. This resulted in the definition of four metamorphosed alteration mineral assemblages and eight chemostratigraphic rock units. The chemostratigraphic results suggest that the lithological and/or structural setting of the Metsämonttu succession is more complex than previously considered. The stratigraphic footwall is mainly characterized by an extensive cordierite + anthophyllite ± biotite ± phlogopite + pyrite ± pyrrhotite (Mg–Fe–S) assemblage dominated by mafic rocks, designated Mafic B1 and Mafic B2, and Andesite A1. The main sulfide mineralization is hosted by tremolite + diopside ± biotite ± phlogopite ± chlorite skarn (Ca–Mg–K). A sericite-bearing muscovite + quartz ± biotite ± phlogopite + pyrite (K–Si–S) assemblage is composed of felsic to mafic protoliths (Mafic B1–B2, Andesite A1, Dacite A1, Dacite B1, Dacite C1) and extends several tens of meters into the stratigraphic hanging-wall. A quartz + pyrite ± muscovite (Si–S) assemblage represents the immediate ore-proximal alteration and is derived from rocks with a rhyolitic composition (Rhyolite A1). Limited drill core samples near Metsämonttu mineralization, along with restricted surface alteration, pose challenges in studying geochemical variations from distal to ore proximal areas and limits the ability to model the shape and size of the alteration zone. Large mass changes suggest that the alteration was hydrothermal, and due to several protolith compositions, the alteration is interpreted to be predominantly discordant to stratigraphy. A 60-m-wide alteration halo surrounds the Metsämonttu deposit. Major and trace elements, namely MgO, Na 2 O, K 2 O, SiO 2 , Fe 2 O 3 , Cu, Zn, Pb, S, Ag, Tl, Hg, Se, Te, Sn, Sb, Rb, and Sr, and the indices modified alteration index (MAI), Ishikawa alteration index (AI), chlorite‑carbonate-pyrite index (CCPI), S/Na 2 O can be used for chemical vectoring, which can assist regional or near-mine exploration. Elements MnO, Ba, Cd, Bi, As, Ni, Co, W, Ga, Mo, and indices Hashigushi index and advance argillic alteration index (AAAI) were less useful as geochemical exploration indicators. [Display omitted] • Study on Paleoproterozoic Metsämonttu Zn–Pb–Cu–Au–Ag deposit in southern Finland. • Volcanic units and alteration types were recognized by geochemistry and petrography. • Alteration assemblages are hosted by previously unrecognized chemical rock units. • Large mass changes in altered rocks support hydrothermal origin of alteration. • Major and trace elements and derived indices provide ore proximity indicators. [ABSTRACT FROM AUTHOR]

Copper and associated gold mineralization in the Mundiyawas-Khera area of western India is hosted by the Proterozoic felsic volcanic rocks of rhyo-dacite composition. Signatures of hydrothermal alteration represented by sericite, epidote, scapolite and carbonates are well observed around the ore mineralization zone. The felsic volcanic rocks with gently to flat sloping REE pattern, variable negative Eu anomaly, intermediate abundances of HFSE and moderate to low Zr/Y anomalies are suggested to be FII, FIIIa and FIV type rhyolite. The felsic volcanic host rock for copper mineralization has a depleted and flat HREE pattern and indicates the crustal source, which is garnet free. Negative Eu anomaly in the rock is probably because of the intracrustal partial melting formed in a rift related environment. The high temperature magmatic activities are probably evolved due to the partial melting of crust at shallow to moderate depths, suggesting an evolved continental crust. The δ13C values of the mineralized carbonate veins range between −10.4‰ and −0.9 ‰ (min = −10.6‰, n = 27), whereas the δ18O values show a range of 16.35‰ to 25.23‰ (min = 21.49‰, n = 27), ideally suggesting a mixed source for the ore bearing fluid. Geological, geochemical and stable isotope data of the Mundiyawas-Khera copper deposit suggest it to be a VMS/VHMS setup and these insights will lead to finding new deposits in the nearby areas, having same stratigraphic horizons and similar lithogeochemical assemblages. [ABSTRACT FROM AUTHOR]