Fumaroles Research Articles

Healing properties of natural mineral water of Tajikistan

Aim. To study the composition and medicinal properties of water from natural mineral springs in the Republic of Tajikistan.Materials and Methods. This study analyzed the climatic and geographical regions, as well as the water quality and chemical composition of four mineral springs: Khoja-Obi-Garm, Obi-Garm, Garm-Chashma, and Shoambary. The research also investigated the influence and effectiveness of these mineral waters in treating skin diseases.Results and Discussion. The Republic of Tajikistan has numerous mineral springs that are used for treating skin conditions and other health issues. Mineral waters in Tajikistan are classified into five types based on their chemical composition: bicarbonate, chloride, sulfate, nitrate, and mixed composition waters. In addition, there are waters with active ions and gaseous elements such as hydrogen sulfide, radon, nitrogen, and methane. Based on temperature, these waters are categorized as cold, warm, or hot/thermal waters. The springs at Khoja-Obi-Garm, Obi-Garm, Garm-Chashma, and Shoambary are hot thermal baths of the bicarbonate-chloride-sulfate-sodium type. In addition to the primary salts and gases, these waters contain biologically active trace elements, including aluminum, titanium, manganese, copper, silicon, molybdenum, strontium, barium, boron, fluorine, and others.Conclusion. Tajikistan holds a leading position in Central Asia regarding the abundance of mineral springs, and the mineral waters from these springs meet the requirements for therapeutic use. These waters contain a variety of chemical elements that exert significant biological effects, and, when used appropriately, can effectively treat many diseases.

Complete genome sequence of Bacillus megaterium strain DY294, a strain of Bacillus isolated from Arshan Resort in Hulunbuir.

The Arshan Resort is a unique mineral spring whose water is used in traditional Mongolian medicine to treat many kinds of diseases. Here, we report the genome sequence of Bacillus megaterium Strain DY294, a strain isolated from the Arshan water collected from Hulunbuir (117°40' E, 48°54' N), China.

Recent advances in adaptation genomics in fumarole fields, an overlooked extreme environment.

Extreme environments and plants thriving in them, known as extremophytes, offer promising platforms for studying the diverse adaptive mechanisms that have evolved in plants. However, research on adaptation to extreme environments is still limited to those environments where model species or their relative can survive. Fumarole fields, an extreme environment often overlooked, are characterized by multi-hazardous abiotic stressors, including atmospheric contamination (high concentration of H2S, SO2, and CO2), high soil temperature (~60℃), and strong soil acidification (pH=2-3). These conditions make fumarole fields a rich source for studying stress tolerance mechanisms in plants. In this review, we highlight the recent ecological, physiological, and genomic advances involved in fumarole field adaptation, and discuss the forward avenues. The studies outlined in this paper demonstrate that the extreme levels of abiotic stressors found in fumarole fields make them unparalleled field laboratories for studying the unknown stress tolerance mechanisms, warranting further genomic assessments. Some studies succeeded in identifying genes associated with fumarole field adaptation and shedding light on evolutionary implications; however, they have also encountered challenges such as limited genome resources and high genetic differentiation from related species and/or neighboring populations. To overcome such difficulties, we propose integrating ecophysiological and genomic approaches, drawing from the recent studies in other extreme environments. We expect that further studies in the fumarole fields will contribute to broadening our general knowledge of the limits of life.

Application of otolith morphometrics in delineating population structure of Aphaniops stoliczkanus (Teleostei: Aphaniidae) in southern Iranian waters

AbstractWidely distributed Species in different geological and ecological environments often exhibit great intraspecific diversity. Aphaniops stoliczkanus (Day, 1872) is an endemic species of Middle East occurring over a vast geographic range in different basins. This species has been observed in freshwater, brackish water and hot sulphur springs; therefore, its populations are known to exhibit considerable morphological variation. In the present study, we have investigated the poorly studied populations of A. stoliczkanus of the Hormuz and Makran basins of Iran in terms of otolith morphology and morphometrics. According to the results, these populations can be divided into two distinct groups including east and west of the Strait of Hormuz. Our results also provide evidence that there is a relationship between otolith morphology and the environment, serving as environmental factors that may influence the formation of specific regions in the otolith shape. Despite the remarkable morphological similarities among otoliths in geographically close populations of Charak and Chiruyeh, our data purposed that geographically these populations have different dorsal tip shapes in their otolith. In comparison to the data from other studies, the otoliths of Qeshm Island appear to resemble the overall shape of otolith found in Oman very closely. However, it is believed that Qeshm Island population was separated from the Hormuz basin populations during the Holocene Sea level rise. Also, the outcomes of this study provide insights into the potential role of environmental factors in shaping intraspecific diversity and the migration patterns of this species within the Persian Gulf.

Trends and Future Directions in Analysing Attractiveness of Geoparks Using an Automated Merging Method of Multiple Databases—R-Based Bibliometric Analysis

Since their creation, geoparks have been among the fastest growing natural environments. Their attractiveness is one of the most important factors for the success of this natural destination. Despite their importance, a bibliometric analysis on geopark attractiveness is missing from the studied databases. The aim of this paper is to synthesise a heterogeneous body of knowledge of geoparks in terms of attractiveness, highlighting the evolution and breadth of the research field. To achieve this, the following objectives were set: (a) to adopt a method based on functions provided by the bibliometrix package to automatically combine databases, namely WoS, Scopus, PubMed and Dimensions, detailing the method used and (b) to analyse the bibliometric indicators in order to identify the trends in the literature and the possible directions for future research. The applied methodology was based on bibliometric analysis using R for non-coders. From the 707 documents retrieved, the validation process resulted in 349 eligible documents published between 2002 and 2024, on which the analysis was carried out. The current study elaborated a method and examined the key information on the topic trends, which were given by production performance, productivity trends, spatial analysis and abstract approach analysis. Additionally, strategic mapping of the conceptual context was performed. Thus, the result provides a description of the automatic method with practical applications. As discerned from the three-dimensional analysis (spatial, temporal and size), the emerging research directions within scientific creativity encompassed (1) forms of tourism practiced in geoparks, especially focused on ecotourism and volcanic tourism; (2) geomorphological features, mineral springs and mud volcanoes; (3) aesthetic aspects, scenic sites and mining heritage; and (4) methodology, data analysis and modelling methods across different regions and countries.

Seismic structure beneath Ebeko Volcano and surrounding areas of Paramushir Island (Kuril Arc) inferred from local earthquake tomography

Paramushir is a large northernmost island of the Kuril Arc in the Russian Far East. Here, we study the northern part of Paramushir, which is dominated by the Vernadsky Ridge with an altitude of around 1000 m above sea level. This ridge is composed of a series of Pleistocene and Holocene volcanoes and includes the presently active Ebeko Volcano, which exhibits frequent phreatomagmatic eruptions and ongoing fumarolic activity. Studying the internal structure beneath Northern Paramushir is important to understand the interrelationship of magmatic, hydrothermal, hydrological and geological processes below Ebeko Volcano. We use seismic data of a portable network consisting of 20 broadband stations installed for one year from the summer 2021 to 2022 and one permanent station in the city of Severo-Kurilsk. We performed the local earthquake tomography inversion, which provided the distributions of Vp, Vs, Vp/Vs and local seismicity in an area of northern Paramushir with lateral extent of ∼20 km and depth of a ∼ 15 km. The results of several tests gave the information about the resolution limitations of the computed model, which were taken into account during its interpretation. In the resulting model, the coexistence of low Vp, high Vs, low Vp/Vs and a seismicity cluster down to ∼10 km below Ebeko indicates the presence of a large gas-saturated area that was formed due to the contacts of liquid fluids with hot magmatic intrusions. The western border of this area coincides with the location of Verkhne-Yurievsky hot water sources and possibly highlights the path of fluids traveling around the hot body below Ebeko. Below the upper part of the eastern slope, we observe a shallow anomaly of low Vs and high Vp/Vs indicating the presence of a near-surface aquifer, confirming the previous results of ambient noise tomography. Below the lower part of the eastern slope, a nearly vertical anomaly of low Vs and high Vp/Vs may represent a fault zone, which is also marked on the surface by a series of lineaments.

Study of radon exposure, chemical and radiological characterization of spring mineral waters from Águas de Lindóia and Poços de Caldas, Brazil

Study of radon exposure, chemical and radiological characterization of spring mineral waters from Águas de Lindóia and Poços de Caldas, Brazil

Natural rhenium sulfide clusters formed under conditions of laser desorption-ionization.

Cluster forms of rhenium sulfides have important practical applications as catalysts in oil refining and thus present high interest. However, only a limited number of rhenium sulfide clusters have been described previously. It is known that cluster formation actively occurs under conditions of laser desorption-ionization; nevertheless, detailed studies of rhenium sulfides under such conditions were apparently not conducted previously. A sample of natural rhenium sulfide, collected from the fumarolic field of Kudriavy volcano (Iturup island, Russia) in 2002, was investigated using the laser desorption-ionization mass spectrometry method. The formed rhenium sulfide clusters were registered by a time-of-flight detector and identified programmatically using the software developed in IPCE RAS. The identification involved a comparison of the distribution of isotopic peak intensities, observed in the resulting mass spectra, with the theoretical probabilities of occurrence of various isotopologues for hypothetical rhenium sulfide species. Over 60 rhenium sulfide clusters of RexSy + and RexSyOz - types containing up to 10 rhenium atoms were formed when a sample of natural rhenium sulfide was exposed to laser desorption-ionization conditions. Several isolated heterometallic ReXMoSY + and ReXMoSYOZ - clusters containing up to eight rhenium atoms were additionally observed in the resulting mass spectra. The species with compositions, for which the electrically neutral analogs are known, apparently were the most stable rhenium sulfide clusters among the detected ones. The obtained data allowed summarizing the patterns of formation of rhenium sulfide clusters under conditions of laser desorption-ionization. The ability of rhenium and sulfur to form cluster species containing from 7 to 10 atoms of rhenium was likely discovered for the first time. The majority of the rhenium sulfide clusters described in this study, notably RexSy + ions containing over seven atoms of rhenium, were apparently not observed previously.

Anatomy of a fumarole field: drone remote-sensing and petrological approaches reveal the degassing and alteration structure at La Fossa cone, Vulcano, Italy

Abstract. Hydrothermal alteration and mineralization processes can affect the physical and chemical properties of volcanic rocks. Aggressive acidic degassing and fluid flow often also lead to changes in the appearance of a rock, such as changes in surface coloration or intense bleaching. Although hydrothermal alteration can have far-reaching consequences for rock stability and permeability, limited knowledge exists on the detailed structures, extent, and dynamic changes that take place near the surface of hydrothermal venting systems. By integrating drone-based photogrammetry with mineralogical and chemical analyses of rock samples and surface gas flux, we investigate the structure of the evolving volcanic degassing and alteration system at the La Fossa cone on the island of Vulcano, Italy. Our image analysis combines principal component analysis (PCA) with image classification and thermal analysis through which we identify an area of approximately 70 000 m2 that outlines the maximum extent of hydrothermal alteration effects at the surface, represented by a shift in rock color from reddish to gray. Within this area, we identify distinct gradients of surface coloration and temperature that indicate a local variability in the degassing and alteration intensity and define several structural units within the fumarole field. At least seven such larger units of increased activity could be constrained. Through mineralogical and geochemical analysis of samples from the different alteration units, we define a relationship between surface appearance in drone imagery and the mineralogical and chemical composition. Gradients in surface color from reddish to gray correlate with a reduction in Fe2O3 from up to 3.2 % in the unaltered regime to 0.3 % in the altered regime, and the latter coincides with the area of increased diffuse acid gas flux. As the pixel brightness increases towards higher alteration gradients, we note a loss of the initial (igneous) mineral fraction and a change in the bulk chemical composition with a concomitant increase in sulfur content from close to 0 % in the unaltered samples to up to 60 % in samples from the altered domains. Using this approach of combined remote-sensing and in situ analyses, we define and spatially constrain several alteration units and compare them to the present-day thermally active surface and degassing pattern over the main crater area. The combined results permit us to present a detailed anatomy of the La Fossa fumarole field, including high-temperature fumaroles and seven larger units of increased alteration intensity, surface temperature, and variably intense surface degassing. Importantly, we also identify apparently sealed surface domains that prevent degassing, likely as a consequence of mineral precipitation from degassing and alteration processes. By assessing the thermal energy release of the identified spatial units quantitatively, we show that thermal radiation of high-temperature fumaroles accounts for < 50 % of the total thermal energy release only and that the larger part is emitted by diffuse degassing units. The integrated use of methods presented here has proven to be a useful combination for a detailed characterization of alteration and activity patterns of volcanic degassing sites and has the potential for application in alteration research and for the monitoring of volcanic degassing systems.

Olivine Time-Capsules Constrain the Pre-Eruptive History of Holocene Basalts, Mount Meager Volcanic Complex, British Columbia, Canada

Abstract The Canadian segment of the Cascade Volcanic Arc (i.e. the Garibaldi Volcanic Belt) comprises more than 100 eruptive centres, spanning the entire Quaternary period (Pleistocene to Holocene in age), and with deposits ranging in composition from alkaline basalt to rhyolite. At least one of the volcanoes is currently active; Mount Meager / Q̓welq̓welústen erupted explosively 2360 years BP and has ongoing fumarolic activity. Long-term forecasting of eruption frequency and style depends on reconstruction of the history and timescales of magmatic processes preceding previous volcanic eruptions. Utilising diffusion chronometry, we investigate the Mount Meager Volcanic Complex focusing on Holocene olivine-phyric basalts (Lillooet Glacier basalts) exposed by the retreat of the Lillooet Glacier. We identify two distinct olivine populations in samples of quenched, glassy basalt lavas that record different magmatic processes and histories. Glomerocrysts of Fo83 olivine phenocrysts, entrained and transported by a hot mafic input, form Population 1. These exhibit resorption and normally zoned outermost rim compositions of Fo76–78; a third of them also show interior reverse compositional zoning. A second population of skeletal microphenocrysts have the same composition as the phenocryst rims (i.e. Fo76–78) and are in equilibrium with the adjacent matrix glass. We estimate the pre-eruptive temperature-fO2 conditions in a shallow reservoir (100 MPa; ~3 km) for a melt with H2O content of 0.5 to 1 wt % as ~1097°C to 1106°C (± 30°C), and NNO + 0.5 (±1.1), respectively. Using these input parameters, we report Fe-Mg diffusion chronometry results for 234 normally zoned profiles from 81 olivine phenocrysts. Diffusion modelling of compositional profiles in oriented crystals indicates pre-eruptive magmatic residence times of 1 to 3 months. These remarkably short residence times in shallow reservoirs prior to eruption suggest very short periods of unrest may precede future eruptions.

Ibn Wāfid Andalusi, a medieval physician, pharmacist, and botanist, with a look at his most important work Al-Adwiyah Al-Mufradah.

The mastery of medical sciences, pharmacy, and botany can be seen in the records of Andalusian scientists. This descriptive-analytical research introduces one of the scientists of the 10th and 11th centuries AD. Medical knowledge and its affiliates are taken from the medical heritage of ancient civilizations. Andalusian scientists changed Andalusia's agricultural and economic situation by adopting new agricultural methods, especially irrigation and planting of medicinal plants. The name of Ibn Wāfid shines among Andalusian scholars. He was one of the theorists in the field of pharmacology in the Middle Ages. His practical method of treating patients is remarkable. His therapies tend to use nutritional methods more than prescribing drugs. He preferred single medications to compound ones. He insisted on curing diseases through hydrotherapy in mineral springs. While working in botany, Ibn Wāfid also specialized in medicine and pharmacy. He also benefits from the experiences of his master Zahrāwi while using the works of Galen, Aristotle, and Dioscorides. One of his honours was the establishment of several botanical gardens for the kings of the time. Ibn Wāfid's attempt at the flourishing of pharmacology, botany, and medicine can be considered a significant contribution to the visibility of these sciences in Medieval Andalusia.

Hidden magma reservoirs: Insights from helium and carbon isotopic compositions in shallow groundwater beneath the Wudalianchi volcanic field, Northeastern China

The lack of strong geothermal manifestations and limited fumarolic activity has sparked widespread debate about the presence of active magma reservoirs beneath the Wudalianchi volcanic field (WVF). Helium (He) in hydrological systems is sensitive and responsive to the mixture of mantle-derived He, making it an excellent tool for deciphering mantle-derived magmatic processes. Through investigating dissolved He and inorganic carbon (DIC) in shallow groundwater of the WVF, we found that He captures mantle characteristics with R/Ra ratios (R equals to 3He/4He ratios, Ra is atmospheric 3He/4He ratio of 1.39 × 10−6) ranging from 0.07 to 2.27 and the highest proportion of mantle-derived He is 30.38 %. In contrast, DIC shows minimal mantle influence, with low concentrations (1.91–7.39 mmol/L) and depleted δ13C-DIC values ranging from −17.9 ‰ to −13.6 ‰. The calculated mantle 4He fluxes in groundwater are 2–3 orders of magnitude higher than that in stable continents and show the signature of volcanic degassing. The high mantle He fluxes and high upward flow rates suggest the efficient release and transfer of mantle-derived He into shallow groundwater through magma degassing. Magma-aging model effectively constraints the period of magmatic activity to within the last 47 ka. These findings, consistent with seismic noise imaging results, support the presence of magma reservoirs in the upper–middle crust. The absence of magmatic carbon signature in groundwater suggests the decoupling of magmatic He and magmatic CO2. Magmatic CO2 may be removed during ascent, possibly being trapped through dissolution or precipitation processes within the low-resistivity bodies identified at ∼2.5 km depth by magnetotelluric imaging. These findings not only contribute to resolving the controversy surrounding the existence of magma reservoirs beneath the WVF but also have broader implications in guiding the exploration and validation of hidden magmatic systems.

Geophysical and geochemical investigations of underwater sulphurous seeps from Western Black Sea (Mangalia area, Romania), in support of habitat conservation

Mangalia area harbors in the western Black Sea a distinctive marine environment thriving under specific hydrochemical conditions, largely influenced by a significant number of sulphurous springs occurring in shallow marine waters. These springs led to the designation of the area as part of the Natura 2000 Marine Protected Area (MPA) network at European level (Underwater Sulphurous Springs from Mangalia - ROSAC0094), as unique hydro-geomorphological features in the region. In 2021 and 2023, two research cruises led by GeoEcoMar investigated underwater sulphurous springs primarily located offshore of Mangalia (Constanţa County, Romania). The study area, located between 17-29 meters water depth and 1.8-3 km offshore, encompasses two marine protected areas: the Underwater Sulphurous Springs from Mangalia (ROSAC0094) and Cape Aurora (ROSCI0281). The research combined geophysical and geochemical techniques and sediment sampling. Considering the susceptibility of these natural systems to human activities such as fishing and dredging, as well as the impact of ecological and climate changes, this paper offers significant insights contributing to the development of effective conservation and management strategies for these environments. The surveys were conducted for benthic habitats mapping, with the objective of improving our understanding of these ecosystems’ distribution, composition and dynamics. As these sulphurous waters are rich in methane, a powerful greenhouse gas, our results also contribute to the inventory of greenhouse gas sources. The results presented in this paper provide valuable new insights into this specific environment, contributing to the understanding of its complex functioning and evolution.

Radioactivity as a driver of bacterial community composition in naturally radioactive mineral springs in the French Massif Central.

Some natural environments on Earth are characterised by high levels of radiation, including naturally radioelement enriched mineral springs in the French Massif Central. Therefore, naturally radioactive mineral springs are interesting ecosystems for understanding how bacterial populations in these springs have adapted to high levels of natural and chronic radioactivity over the very long term. The aim of this study was to analyse the bacterial communities of sediments from five naturally radioactive mineral springs in the French Massif Central, sampled in autumn 2019 and spring 2020, and to observe whether radionuclides, compared to other physicochemical parameters, are drivers of the bacterial community structuring in these extreme environments. Physicochemical measurements showed that two springs, Dourioux and Montagne had high radioelement concentrations/activities (uranium, thorium and radon). Analysis of the structure of the bacterial communities, by next generation sequencing based on 16S rRNA gene sequencing, showed that the presence of radionuclides in Dourioux and Montagne, did not lead to a reduction in bacterial diversity and richness compared to the other springs. However, Dourioux and Montagne were characterised by specific bacterial populations, whose presence correlates with the radioelement concentrations/activities measured in these springs. This suggests that radioelements could partly explain the structuring of bacterial communities in these springs. In addition, several of these operational taxonomic units (OTUs) specific to Dourioux and Montagne, mainly affiliated to Proteobacteria, Firmicutes, Acidobacteria, Actinobacteria, and Bacteroidetes, could be involved in the biogeochemistry of radionuclides through different mechanisms (biosorption, biomineralisation, bioaccumulation, and bioreduction), which would allow the development of other bacterial species sensitive to these metals/radioelements. In particular, the co-occurrence of sulphate and/or iron-reducing bacteria, capable of bioreducing uranium, with fermentative bacteria, releasing sources of organic carbons, reflects associations of bacteria with complementary functions that allow them to grow in this peculiar environment and maintain a high diversity in these extreme environments. This study has provided a better understanding of the structuring of bacterial communities exposed to ionising radiation for thousands of years in naturally radioactive environments.

The Evolution of Small Town Spa Resorts in the Global South: The Historical Pathway of Montagu, South Africa

An important resource for small town tourism is maximising the local advantage of natural mineral springs. Only a small international literature exists on the evolution of spa resorts with scant writings for the Global South. For small town South Africa the histories of spa tourism mostly are unrecorded. This article addresses this knowledge gap by investigating the historical development of one spa tourism resort, namely Montagu in the Western Cape. Archival and documentary sources are utilised to analyse the tourism development of this small town from its formal establishment in the early 1850s to the closing apartheid years during the late 1980s. It is shown that Montagu’s rise was part of the wider growth of South Africa as a health destination which was anchored upon its assets of climate and mineral springs. The thermal springs of Montagu put the town on the tourist map resulting in its declaration as a health resort and emergence as a popular holiday destination. By the time of the apartheid period Montagu was becoming a more leisure-tourism dominated and a less health focussed destination.

Detecting Geothermal Phenomena at Sikidang Crater Area Based on Ground Penetrating Radar Method

Abstract Sikidang Crater (2000 masl) is one of the leading tourist sites in the Dieng area. However, not many people realise that Sikidang Crater is located in the Dieng Volcanic Complex where most of the volcanoes belong to the type A category. Sikidang Crater is one of the main geothermal manifestations occupied by mud pools, solfatara, fumaroles, and altered rocks. These manifestations have potential geological hazards such as toxic gases, base surge, and mud explosions. On the other hand, it has a high level of human activity that increases the risk of disasters. As an effort to prevent and mitigate disasters, it is necessary to know the subsurface geological conditions of the crater. This study aims to determine the subsurface geological conditions of the crater. This research uses the methods of detailed geological mapping, manifestation observation, and Ground Penetrating Radar (GPR) geophysical survey. The tool used is Akula Geoscanner 9000C running at 64.75 Hz frequency, capable of penetrating 50 meters deep, and has a vertical resolution of > 0.85 meters. Sikidang Crater is located at the southeastern foot of Mount Pangonan and it forms semicircular like a horseshoe. According to Van Zuidam, the crater is classified as a solfatara and fumarole field geomorphology unit. The lithology of this area is dominated by the eruption products of Mount Pangonan. In general, radargrams resulting from GPR surveys show various amplitudes of reflected electromagnetic waves. This is consistent when correlated with the variation in rock density of the research area. At some points, there is a decrease in electromagnetic wave velocity due to contrast in dielectric constant values, which is interpreted as geothermal fluid flow towards the surface. The potential level of geothermal fluid flow is classified into high, medium, low, and none based on the density of potential points seen in the radargram.

Geoturystyczne aspekty miejscowości uzdrowiskowej UNESCO Mariańskie Łaźnie

The West Bohemian spa triangle is an area with a rich occurrence of mineral springs, which are found on a relatively small area. It includes Mariánské Lázně, Karlovy Vary and Františkovy Lázně. These spas are among the most important spa towns of global importance. This fact is also evidenced by the fact that this spa area was registered in 2021 on the UNESCO World Heritage List. The cities of this triangle are unique not only in terms of balneology, but also in terms of architecture. Even though Mariánské Lázně is the youngest of these cities, some important visitors have ranked it among the most beautiful of them. Many healing springs were responsible for the rapid development of this city. This article describes the interconnectedness of both geological and selected architectural attractions that can be the target of tourist activities in this city.

Update of the Interpretive Conceptual Model of Ladeira de Envendos Hyposaline Hydromineral System (Central Portugal): A Contribution to Its Sustainable Use

The aim of this paper is to describe the surveys performed in order to update the interpretive conceptual circulation model of the Ladeira de Envendos hyposaline hydromineral system (Central Portugal). The geology of the Ladeira de Envendos region is strongly controlled by the Amêndoa-Carvoeiro synform, of Ordovician-Silurian age, presenting continuous and aligned quartzite ridges on the NE flank, that form the basic structure of a set of inselbergs. The physico-chemical analysis of the Ladeira de Envendos natural mineral spring and borehole waters was provided by the Super Bock Group Enterprise (Concessionaire of the Ladeira de Envendos). Furthermore, two sampling campaigns took place to increase knowledge on the isotopic composition of the studied natural mineral waters. The stable (δ2H, δ18O) isotopic data indicate that local meteoric waters infiltrate around 400 m altitude and evolve to the natural mineral waters (of Cl-Na facies) through a NW–SE underground flow path ascribed to the highly fractured and permeable quartzite rocks. From recharge to discharge, the infiltrated meteoric waters acquire silica (±9 mg/L) due to water–quartzite rock interaction. These natural mineral waters emerge at temperatures around 21 °C, being the up flow of these waters controlled by the rock fractures and local faults. The natural mineral waters mean residence time range between 25 and 40 years, as indicated by the 3H content of these waters, enhancing an active recharge of this hydromineral system. The results obtained indicate existence of three hydrogeological subsystems, ascribed to three inselbergs, with similar groundwater circulation paths. These multi and interdisciplinary studies should be seen as an important contribution to the sustainable management of this type of natural mineral water resources.

Reconstructing the Belbaşhanı Pumice Plinian eruption, Hasandağ Volcano, Turkey

Hasandağ volcano (Central Anatolia, Turkey) has recently underwent an increase in local seismicity and fumarolic activity since 2013. In the past, this volcano has produced multiple large explosive eruptions during the last million years. The Belbaşhanı Pumice is the product of a sub-Plinian to Plinian eruption dated at ~ 417 ± 20.5 ka (40Ar/39Ar). Here, we present a complete volcanological study including stratigraphy, glass chemistry, pumice morphology, geochronology, and eruption source parameters with the associated uncertainties, to characterize the Belbaşhanı Pumice eruption. The eruption involved a column of 18–29 km in height, with the main dispersal axis towards the northeast. A pumice layer up to ~ 17-m-thick accumulated in proximal deposits along the Belbaşhanı path, and up to 2-m-thick in medial-distal areas (~ 18 km northeast from the vent). The high and tubular vesicularity of the pumice clasts indicates that the Belbaşhanı eruption was predominantly magmatic. The bulk volume of the Belbaşhanı Pumice fallout deposit has been estimated as 0.5 and 8 km3 (with ~ 2 km3 being the mean value), which corresponds to Volcanic Explosivity Index (VEI) of at least 4 and up to 6. Both isopach and isopleth maps indicate that the volcanic vent may have been located at the intersection of the Tuz Gölü fault and Ulukışla caldera, within the Hasandağ volcanic complex. The glass composition of Belbaşhanı Pumice confirms that the eruption belongs to the Hasandağ magmatic system. The reconstruction of the Belbaşhanı Pumice eruption represents an essential baseline in providing volcanological constraints for further investigations of tephra fallout hazard assessment in Central Anatolia, especially considering that a new Plinian eruption cannot be ruled out at Hasandağ volcano in the future. The chemical and geochronological datasets presented here could aid in refining tephrochronological correlations, with the goal of synchronizing paleoenvironmental and paleoclimatic records alongside archaeological sites.

Regional Hydro-Chemistry of Hydrothermal Springs in Northeastern Algeria, Case of Guelma, Souk Ahras, Tebessa and Khenchela Regions

Hydrothermal units are characterized by the emergence of several large-flow thermo-mineral springs (griffons), each with varying temperature and physico-chemical characteristics depending on the point of emergence. It seems, however, that there is variability between the different systems, although it is not easy to characterize it because the variability within each system is high. The regional dimension of the chemical composition of thermal waters is, therefore, an aspect that has received very little attention in the literature due to the lack of access to the deep reservoir. In this study, we investigated the spatial variability, on a regional scale, in the characteristics of thermal waters in northeastern Algeria, and more specifically the hydrothermal systems of Guelma, Souk Ahras, Khenchela and Tébessa. Thirty-two hot water samples were taken between December 2018 and October 2019, including five samples of low-temperature mineral spring water. Standard physico-chemical parameters, major anions and cations and lithium were analyzed. The data were log-transformed data and processed via principal component analysis, discriminant analysis and unsupervised classification. The results show that thermal waters are the result of a mixture of hot waters, whose chemical profile has a certain local character, and contaminated by cold surface waters. These surface waters may also have several chemical profiles depending on the location. In addition to the internal variability in each resource, there are differences in water quality between these different hydrothermal systems. The Guelma region differs the most from the other thermal regions studied, with a specific calcic sulfate chemical profile. This question is essential for the rational development of these regional resources in any field whatsoever.