Local Geology Research Articles

ANALYZING CLIMATE SHIFTS: PATTERNS OF TEMPERATURE AND PRECIPITATION IN PAKISTAN

As of today, mankind faces an existential threat in the form of climate change. The geological location and other anthropogenic occurrences make Pakistan rank among the top-10[Formula: see text]countries worldwide most affected by climate change and natural tragedies. This review provides an in-depth examination of the shifting patterns of temperature and precipitation in Pakistan, highlighting the significant impacts of climate change on the region. Significant differences in temperature have been reported in Pakistan, indicating that the maximum and minimum annual temperatures varied at the rates of 0.12–0.29°C/decade and 0.10–0.37°C/decade, respectively. Annual precipitation shows notable fluctuations over the decades, highlighting periods of both surplus and deficit; especially, precipitation in the year 2023 was 16% above the long-period average of 1961–2010 with 344.1[Formula: see text]mm. When the air temperatures continue to rise, it is imperative for Pakistan to enhance its resilience to climate change through improved infrastructure, sustainable agricultural practices, and effective water management. This study also reviews the disastrous effects of climate change on Pakistan, especially the recent occurrences of flooding and heatwaves.

Comparisons and characteristics of site amplifications using noise and earthquake data: Examples from the Malta Seismic Network

In the past decade, numerous studies on the amplification effects due to the local geology have been conducted in the Maltese islands (Central Mediterranean). Due to the lack of permanent seismic stations on geological areas of concern, ambient noise techniques were utilised. The areas of interest are characterised by clay, that can reach a thickness of 75 m, buried beneath limestone which introduces a velocity inversion in the stratigraphy. With the expansion of the Malta Seismic Network (MSN) to three stations in such zones, the possibility of confirming and further investigating the results using empirical data arises. Here we present results, using 3 years of data including time domain and frequency-domain analysis in terms of Standard Spectral Ratio (SSR) and earthquake H/V. In particular, we note that the amplifications obtained using the SSR technique are significantly higher than those obtained using both noise and earthquake H/V techniques. Additional peaks below 1 Hz of significant amplitude are also obtained on the SSR curves. By separating the earthquake data set on the basis of distance from the islands, we show that this amplification is source-dependent, and that the high amplification values originate from larger, more distant earthquakes in the Hellenic arc.

Modelling noise H/V spectral ratio in a laterally inhomogeneous layered medium

SUMMARY Central to the task of seismic hazard assessment is the evaluation of potential amplifications due to site effects. The horizontal-to-vertical spectral ratio (HVSR) of ambient seismic noise (ASN) is a widespread measurement to assess the predominant soil frequency of a given site and estimate the wave velocities of the subsoil stratigraphy using inversion schemes. In practice, the inversions are currently made, assuming flat layers. In fact, HVSR measurements may show significant lateral and azimuthal changes due to the spatial variations of local geology, which can introduce uncertainties into the characterization of a site. This suggests the importance of considering detailed measurements of lateral and angular variations in layered settings. Inversion of soil properties at depth for horizontally layered media has become feasible assuming that ASN constitutes a diffuse field, that is, produced by equi-partitioned uniform illumination and/or by random sources and the ensuing multiple scattering by heterogeneities. Under the diffuse field assumption (DFA), the HVSR have been modelled by calculating the imaginary parts of the Green's function (IMGs) when source and observer coincide at the same point. In this work we use the 3-D indirect boundary element method (IBEM) to model the HVSR for each independent horizontal direction referred to here as directional-HVSR for layered media with lateral inhomogeneity. The IMGs at the source required to get HVSR have locality properties that depend on frequency and may imply significant economies in the calculation. For simple models we modelled the IMGs approximately using an adaptive meshing scheme that accounts both for the locality of the problem and the diffraction properties of waves at low and high frequencies. The obtained directional-HVSR displays variations in both frequency and azimuth. The results also show that layer interface variations can lead to ‘spots’ of higher wave excitation associated to local resonant modes. This shows the importance of HVSR in forecasting earthquake response and suggests the need for denser field measurements to study lateral and azimuthal variability. In order to show the reality of directional-HVSR, field data from Chalco, a soft soil site at the southern part of the Valley of Mexico, have been preliminarily analysed.

Combining Two Distinct Methods to Resolve Spatial Variation in Attenuation and Earthquake Source Parameters

ABSTRACT Stress drop is a fundamental parameter in ground-motion modeling and seismic hazard assessment, but spectral estimates are subject to considerable uncertainties. A variety of factors cause different methods to yield different results, including the complexity of the seismic source, the assumptions inherent in the models used, the limited range of frequencies available, and the inherent difficulty in removing the propagation effects along the wave path. A primary challenge is determining whether the observed variations in spectral stress-drop estimates represent characteristics of the seismic source or the propagation path. We compare the performance of two methods applied to the 2019 Ridgecrest, California, earthquake sequence, each of which addresses the trade-offs between propagation and source in different ways. The first method, referred to as the spectral-fitting approach, operates on the hypothesis that the path effects remain constant across the spatial and temporal range of the sources under investigation. This approach assumes a level of uniformity in the propagation effects that simplifies the analysis. The second method, referred to as the spectral ratio approach, is based on the hypothesis that a small, collocated event will experience identical propagation effects to the earthquake of interest, potentially accounting for smaller scale variation in propagation effects. Our comparison reveals that the choice of method is not only influenced by the specifics of the data and the seismic events but also significantly constrained by the geological heterogeneity and consequent spatial variability of site and propagation effects in the study area. If an approach involves assuming a homogeneous attenuation structure, any spatial variation in attenuation structure will lead to this variation being incorrectly mapped into apparent source stress-drop variations. Understanding the local geology and structural heterogeneity, combined with using methods with contrasting underlying assumptions are good approaches to improving the reliability of estimated spectral stress drops.

Southern California basin and non-basin classification algorithm for ground-motion site amplification model applications

In ground-motion modeling, the estimated level of ground shaking at any given location for an expected earthquake scenario depends on the contributions from the source component (type of fault mechanism and size of the fault slip), the path component (distance between the source and site of interest, and the geologic characteristics of that region), and the site component (the local geology at the site of interest). Each component captures some level of variability and uncertainty in the overall ground-motion estimate. In particular, the site component represents the potential amplification (or de-amplification) of the seismic waves that may lead to magnified and prolonged ground shaking at any given location. This feature is referred to as site effects and in current ground-motion models (GMMs) is dependent on the time-averaged shear wave velocity in the upper 30 m of the earth’s crust ( Vs30) and the depth to a particular shear wave velocity iso-surface (“basin depth,” zx). The latter is responsible for determining the contributions of basin effects, which is additional ground-motion amplification due to three-dimensional effects such as trapped seismic waves that lead to surface wave generation. However, an evaluation of the relationship between zx and basin locations reveals cases of misclassification that is a result of geologic variability (i.e. zx is not sufficient in differentiating basins from non-basins). The study performed in this article proposes a resolution in the form of a statistical classification model that determines the probability of a location residing within or outside a basin based on simple geologic features such as ground surface texture.

Proposed Method For Studying Radon Exhalation

Objective: The main objective was to test the closed radon exhalation methodology, with AlphaGuard radon detector, for different grain sizes of a granite rock sampled from central area of Belo Horizonte and propose experimental methods for its determination. Theoretical Framework: Natural radioactivity accounts for about 80% of the average annual radiation dose humans receive, primarily due to primordial radionuclides in the Earth’s crust. The World Health Organization (WHO) recommends national radon (Rn) exposure mapping programs based on geological studies due to the significant contribution of Rn gas to annual radiation doses. Studies indicate that granitic and metamorphic rocks, black shales, phosphate rocks, and some carbonate rocks are common radon sources. Rn is generated in soil and migrates through soil pores, entering buildings through cracks and openings. Rn transport is influenced by factors like local geology, humidity, and temperature. Method: The study tested radon exhalation from granite samples in center of Belo Horizonte using a proposed method with AlphaGuard in an exhalation circuit. Results and Discussion The studied method proved to be effective with particle sizes up to 16#. For very fine particle sizes, the air flow is hampered and therefore reduces the effectiveness of transporting the radon-filled gas. Research Implications: The implications of this research are discussed, providing insights into radon exhalation method in a closed circuit and its challenges. This study contributes to literature by studing exhalation rate is vital for estimating radiation risk from many kinds of materials and the indoor radon.

Site characterization of Sikkim Himalaya using HVSR

The northeastern state of Sikkim lying in central segment of the Himalayan orogen is a seismically active region which was plagued by the recent 2011 Mw6.9 earthquake. Analysis of local earthquakes recorded at the recently deployed seismic network of 27 broadband seismic stations revealed seismogenic zone extending down to lower crustal depths with a predominant strike-slip faulting mechanism. Persistent seismicity in a region with complex tectonic setting makes it imperative to study the site characteristics crucial for determining the local site conditions. Here, we harness the noise and local earthquakes records from the Sikkim network to compute horizontal-to-vertical spectral ratio (HVSR) for site characterization. Local geology and topography are observed to incite distinctly intricate trends in the HVSR curves. The thick sedimentary deposit of the Himalayan foreland basin causes high amplification (∼7) at low resonant frequencies (<1 Hz). The HVSR curves in the western section of Main Central Thrust Zone exhibits distinct double amplification peaks (∼2.5 at 1 Hz and 5 Hz) under the influence of the parallely dipping sheets of the duplex structure. Whereas, the eastern section of Main Central Thrust zone exhibit a rather irregular trend owing to its proximity to the transitioning lithological unit. The central section prone to landslides has characteristic peaks at 2 Hz and 8 Hz, indicative of the geometry of the sliding surface. Effects of towering topography and high wind speeds at corresponding elevations are observed to result in anomalously high amplification (∼25) at low frequencies (< 1 Hz). Directional amplification along discrete azimuth signifies the pronounced effect of topography and geometry of lithotectonic units in site response. Locally varying site response with prevalent seismicity amplifies the seismic hazard risk potential of Sikkim Himalaya.

A 30 Arcsec Resolution VS30 Map for Mainland China Using Refined Topographic Slope-Based Cokriging (SCK) Model

ABSTRACT In 2022, we proposed a VS30 proxy model based on the Cokriging method, integrating local VS30 measurements with topographic slope data (SCK model, Zhou et al., 2022). Utilizing this model, a VS30 map for mainland China was developed based on 7797 local boreholes. However, the initial VS30 map was produced with a coarse grid resolution of 360 arcsec and did not comprehensively cover mainland China due to sparse distribution of boreholes in certain areas. In this study, we refined the SCK model by explicitly accounting for the influence of surrounding topographic slopes, incorporating more distant VS30 measurements, and improving the spatial distribution of VS30 measurements used in the model calculation. Tests based on virtual cases were conducted to evaluate the characteristics of the refined SCK model. In addition, 142 VS30 measurements from strong-motion stations in western China were added to enhance spatial coverage and model accuracy in these regions. Employing the refined SCK model and the expanded VS30 data set, a new VS30 map for mainland China was generated. This updated map features a higher grid resolution of 30 arcsec and covers the entirety of mainland China, showing reduced estimation errors and improved continuity. Comparisons with the U.S. Geological Survey Global VS30 Mosaic indicate that the results from the refined SCK model are more reasonable, as evidenced by local topography, VS profiles, lithologic profiles, and geology map, which better capture the impact of local geomorphological differences and climatic conditions on VS30 values.

Soutpansberg Mountain: a spider hotspot in the Limpopo Province of South Africa (Arachnida, Araneae)

The Soutpansberg Mountain (SM) range in the northern part of the Limpopo Province within the Vhembe Biosphere Reserve, is a refuge for high diversity of organisms due to its geological history and location. As part of the South African National Survey of Arachnida (SANSA), the spider diversity of the Soutpansberg Mountain was determined over 27 years: 58 families, 293 genera, and 585 species were recorded. The Salticidae with 85 species, followed by Thomisidae (81 species), Araneidae, and Gnaphosidae, with 45 species each, are the most species-rich, while 11 families are represented by single species. Global distributions, endemicity, and conservation assessment are provided for each species using IUCN criteria. Most species (516, 88.1%) are widely distributed with no known threats and are of Least Concern, whereas eight species (1.4%) are of special concern. Of these, five species are Rare and one each is Critically Rare, Vulnerable, and Near Threatened. Twenty-five new species have been described from the SM since 1997, but 17 species (2.9%) are still Data Deficient, and 44 species were not evaluated due to unresolved taxonomy. The SM represents a spider biodiversity hotspot in the Limpopo Province, representing 25.4% of the total spider fauna of South Africa and 64.3% of the known spider fauna of the Limpopo Province.

Methods to identify and distinguish the effects of weathering and landslides on sediment granulometry

Urbanization has resulted in the widespread development of built-up areas, often without considering the local geology and geomorphology. To improve risk assessments related to landslides, it is essential to determine the physical and chemical properties of sediments. The aim of this study is to exemplify an already mobilized and reworked layer based on granulometric properties of the sediments and characterize the chemical and physical properties which have changed during or after the mass movement. Ten red clay layers were sampled near Kulcs (Hungary) from a sliding surface and its environment. We measured grain size distribution, major element and modal composition, furthermore, conduct particle shape analysis, respectively. Grain size distribution suggest that samples from the sliding surface are weathered, with the exhibiting reworking characteristics. We calculate the weathering index from the major elements, which, in combination with the particle shape analyses of the silt fractions, indicate that the morphological parameters of the samples are in relation with weathering index. According to our results, while a fresh sliding event leaves marks on the granulometric properties, the main process which affects the grain morphology is the chemical abrasion (post the mass movement) and not the landslide event.

Indirect hazard evaluation by the prediction of backbreak distance in the open pit mine using support vector regression and chicken swarm optimization

Backbreak is one of the undesirable phenomena in open-pit mines and causes several adverse hazards, such as lanslide, rock falling off and bench instability. Backbreak is influenced by many factors, such as rock properties, blasting design and local geology, so it is very difficult to assess and evaluate backbreak accurately. Therefore, controlling and accurate prediction of backbreak distance are crucial tasks to reduce hazards in open-pit mines. For this, soft computing-based techniques are considered to be an effective means, as they can integrate various sophisticated factors into a function to predict and evaluate backbreak distance. So, in this study, support vector regression (SVR) based techniques and three different types of bio-inspired meta-heuristic (BIMH) algorithms, such as chicken swarm optimization (CSO), whale optimization algorithm (WOA) and seagull optimization algorithm (SOA) are used to develop backbreak distance prediction models. The support vector regression is used as a regression tool and BIMH algorithms are used to optimize the hyper-parameters in the support vector regression. Four different types of evaluation metrics are utilized to assess the model performance, namely coefficient of determination (R2), mean square error (MSE), mean absolute error (MAE) and variance account for (VAF). An integrated evaluation system is adopted to provide overall performance for each backbreak prediction scenario. It can be indicated that CSO-SVR based backbreak prediction models can procure the best comprehensive performance and also show the best calculation efficiency. Detailed results include R2, VAF, MSE and MAE equal to 0.99475, 0.034, 99.477 and 0.1553 for a testing set and 0.97450, 0.1633, 97.466, and 0.1914 for a training set which can be said to be an excellent prediction result. By doing this, the hazard risk induced by backbreak can be indirectly assessed. In addition, it is also found that some superior performance can be obtained in some evaluation metrics compared with previous studies which utilized the same backbreak dataset for prediction.

Unraveling the regional environmental ecology dominated baijiu fermentation microbial community succession and associated unique flavor.

Chinese baijiu as one of the famous distilled liquor in which fermented in open environments, with various microorganisms (i.e., bacteria, fungi, and yeast) involved in their brewing process, and created corresponding unique flavor. However, the sources of environmentally enriched microbial communities associated with liquor fermentation are still being characterized yet. Given the dependence of microbial growth and reproduction on environmental ecology, it is important to understand the correlation between baijiu fermentation microbial community and surrounding environmental ecology (i.e., temperature, humidity, wind, and precipitation). This study systematically overviewed the sources of microorganisms in the Jiang-flavor-Baijiu fermentation system. The results showed that microorganisms in baijiu brewing (i.e., mold, lactic acid bacteria, and yeast) mainly originated from surrounding environmental matrices, including the air (i.e., Yeast, Streptomyces and Bacillus), soil (i.e., Xanthomonas, Methanococcus and Comamonas) and water (i.e., Flavobacterium, Acinetobacter, and Pseudomonas) via atmospheric transport, raw material transfer and surface runoff. In addition, the unique baijiu fermentation microbial community diversity depends on local geology and meteorological conditions, highlighting that the structural stability and diversity of the microorganisms in the Baijiu brewing process dominated by local environmental ecology. We also explored the regional environmental conditions on the microbial community and found that the unique Jiang-flavor-Baijiu fermentation microbial community diversity depends on local geology and meteorological conditions. The Jiang-flavor-Baijiu workshop is located in the basin of the middle-and low latitude mountainous areas, with sufficient solar irradiation and rainfall, high air humidity, and low wind speed that favor the growth and propagation of Baijiu fermentation microorganisms. Therefore, the obtained conclusions provide new insights unraveling the key factor controlling the unique flavor of Chinese Baijiu, where protecting the ecology of baijiu brewing-regions is fundamental for maintaining the long-term quality of baijiu.

A new expression for fluid factor using AVO intercept and gradient: Theory and application on gas sand reservoirs from offshore Australia

Numerous amplitude variation with offset (AVO) fluid indicators have proven to be sensitive to the presence of hydrocarbons. Mathematically, these fluid indicators measure the deviation of seismic responses of hydrocarbon reservoirs from their background in a specific domain. We develop a new expression for the fluid factor commonly used in AVO analysis and interpretation. The expression is a function of the common AVO intercept and gradient, along with a weighting coefficient that suppresses the contribution of lithology and other factors unrelated to fluid content. The coefficient also assists in calibrating the fluid factor to the local geology. We compare the performance of our fluid factor with existing fluid factors. All the fluid factors are tested on a worldwide collection of P- and S-wave velocity and density measurements. The testing is followed by application on synthetic data before applying the attribute on real data from the Northwest Shelf of Australia. In the latter application on the real data, we use two wells for calibration purposes, and the third as a blind well. Our fluid factor demonstrated high capability in detecting the targeted gas zones at the three well locations and identifying new prospective zones.

Environmental risks associated with quarry activities and its anthropogenic changes in Weija Hills, Ga South Municipal, Ghana

Quarrying has become an important socio-economic activity in many societies as it provides several services for human well-being. Weija Hills at the Ga South Municipality in Ghana has been witnessing quarrying activities at various sections of the hills causing a series of environmental problems. The study examined the changes that have occurred in the geological structure of the Weija Hills and its environmental hazards. The study employed the mixed method approach following the exploratory sequential research design. The primary data were collected directly from field observation during which much data was gathered including photographs. The Digital Elevation Model (DEM) was used for elevation changes between 2007 and 2014. The Limit Equilibrium Method (LEM) was used for slope stability analysis. The study found that the Weija Hills's local geology is still stable. However, serious environmental problems such as erosion taking place and large quantities of weathered and eroded sediments being carried downslope any time it rains blocking the Mallam-Kasoa Highway making it risky for road users. We recommended that the Minerals Commission and other stakeholders should collaborate and reclaim the land.

Assessment of drinking water quality and identifying pollution sources in a chromite mining region

Water sources near mining regions are often susceptible to contamination from toxic elements. This study employs machine learning (ML) techniques to evaluate drinking water quality and identify pollution sources near a chromite mine in Iran. Human health risks were assessed using both deterministic and probabilistic approaches. Findings revealed that concentrations of calcium (Ca), chromium (Cr), lithium (Li), magnesium (Mg), and sodium (Na) in the water samples exceeded international safety standards. The Unweighted Root Mean Square water quality index (RMS-WQI) and Weighted Quadratic Mean (WQM-WQI) categorized all water samples as 'Fair', with average scores of 67.95 and 67.19, respectively. Of the ML models tested, the Extra Trees (ET) algorithm emerged as the top predictor of WQI, with Mg and strontium (Sr) as key variables influencing the scores. Principal component analysis (PCA) identified three distinct clusters of water quality parameters, highlighting influences from both local geology and anthropogenic activities. The highest average hazard quotient (HQ) for Cr was 1.71 for children, 1.27 for adolescents, and 1.05 for adults. Monte Carlo simulation for health risk assessment indicated median hazard index (HI) of 4.48 for children, 3.58 for teenagers, and 2.98 for adults, all exceeding the acceptable threshold of 1. Total carcinogenic risk (TCR) exceeded the EPA's acceptable level for 99.38 % of children, 98.24 % of teenagers, and 100 % of adults, with arsenic (As) and Cr identified as the main contributors. The study highlights the need for urgent mitigation measures, recommending a 99 % reduction in concentrations of key contaminants to lower both carcinogenic and non-carcinogenic risks to acceptable levels.

Urban geoheritage and degradation risk assessment of the Sokograd fortress (Sokobanja, Eastern Serbia)

Abstract Sokobanja is a well-known spa centre in East Serbia, whose popularity is mostly based on its natural heritage (thermo-mineral springs, waterfalls, canyons, caves, and pits). However, built heritage also offers significant potential for developing geotourism. This article aims to assess the geoheritage values of the geocultural site Sokograd fortress to support geotourism development in this area. For the assessment of geotourism potentials, the urban geoheritage assessment model (UGAM) was applied. To support the criteria of UGAM (e.g. variety of geodiversity and educational potentials), a macroscopic mineralogical–petrographical observation of the building stone was performed. The results revealed significant educational potentials, especially concerning petrodiversity, with sedimentary rocks (limestone, sandstone, tufa, and conglomerates). By comparing the obtained results with the local geology, it is recognized that the building stone was mainly of local provenance. The UGAM parameters, such as geocultural and ecological values, as well as a variety of geodiversity, confirmed that Sokograd has great potential for urban geotourism development. After all, the assessment of degradation risk was performed and revealed that tourism development cannot cause serious threats to the site, but tourism has to be adequately regulated and managed in a sustainable way. The results of this study can provide information to policymakers, local governments, and other interested stakeholders on whether and how to develop urban geotourism at the Sokograd fortress in the upcoming period.

Design Thinking of Smart School Emergency Tents Modular Based as Post-Disaster Recovery

Abstract Indonesia’s geological location has a significant impact on disasters in Indonesia. This disaster caused economic losses, casualties, and psychosocial disorders, namely post-traumatic stress disorder, especially at vulnerable ages, one of which was students. This research aims to develop innovations related to post-disaster recovery efforts for learning activities that were hampered by damage to school buildings by paying more attention to healing Post Traumatic Stress Disorder (PTSD) in students. The method used is the Design Thinking Framework which consists of Emphatize, Define, Ideate, Prototype, and Testing. Data collection techniques use literature study, indirect observation, and Forum Group Discussion. Data analysis uses descriptive qualitative by describing the results of observations, literature studies, and focus group discussions. The results is Modular-Based Smart School Emergency Tents prototype. The originality or value of this research lies in the idea of an emergency school tent that has a personal energy source, portable tables, and is modular based. The module that accompanies this tent guides teachers in carrying out trauma healing for students who are indicated to be experiencing post-traumatic stress disorder.

The Permian Watershed tungsten deposit (northeast Queensland, Australia): fluid inclusion and stable isotope constraints

The Watershed scheelite deposit is located in an extinct fore-arc basin in the Mossman Orogen of North Queensland. This fore-arc region comprises multiply deformed, Ordovician–Silurian metasedimentary rocks of the Hodgkinson Formation, and it was intruded by Carboniferous–Permian granites of the Kennedy Igneous Association. At Watershed, the Hodgkinson Formation includes strongly deformed skarn-altered conglomerate, psammite and slate units, which record four deformation events that evolved from ductile (D1–3) to brittle–ductile (D4). Early, D1–2 scheelite mineralisation in Carboniferous monzonite and skarn-altered conglomerate formed during regional prograde metamorphism, which reached upper greenschist to lower amphibolite facies conditions. Permian, D4 scheelite mineralisation was deposited in transtensional, shear-related veins, vein haloes and skarn-altered conglomerate during retrograde, lower greenschist facies metamorphism. During D4, four stages of retrograde alteration (retrograde stages 1–4) affected the rocks. Fluid inclusion assemblages in retrograde stage 2, vein scheelite and quartz are characterised by a low-salinity H2O–NaCl ± CH4 fluid (XCH4 <0.01, 1.4–8.0 wt% NaCleq). The fluid inclusions show evidence for fluid mixing between a low (∼0 wt% NaCleq) and a medium (<8 wt% NaCleq) saline fluid. Scheelite mineralisation P–T conditions were determined at ∼300 °C and 1–1.8 kbar (i.e. a depth of 3.7–6.7 km), indicative of a high geothermal gradient (35–75 °C/km), which was likely caused by the heat from the Permian granites. The presence of pyrrhotite and arsenopyrite in D4 veins (retrograde stage 4), plus graphite and methane in the fluid inclusions in scheelite, indicates reduced mineralisation conditions. Oxygen isotope compositions (δ18OVSMOW) of retrograde stage 2 scheelite (+3.8 to +7.3‰), plagioclase (+7.0 to +11.8‰) and quartz (+12.6 to +15.5‰) indicate a fluid temperature of 306 ± 56 °C with δ18OVSMOW values between +4.7 and +8.3‰. Retrograde stage 3 muscovite δDVSMOW (−73.4 to −62.7‰) and δ18OVSMOW (+11.5 to +13.2‰) values were used to calculate the O–H isotopic compositions of the fluids in equilibrium with the minerals at various possible temperatures (250–300 °C). The results are consistent with a metamorphic origin for the mineralising fluid. Sulfur isotope compositions (δ34SCDT between −2.5 and +2.8‰) for vein-hosted, retrograde stage 4 sulfides indicate that sulfur could have come from seawater or seawater sulfate, which is consistent with the local geology, even though this range overlaps with magmatic sulfur isotope compositions. Metamorphic fluids probably originated from devolatilisation reactions in the Hodgkinson Formation during prograde metamorphism. Permian intrusions acted as heat source enhancing metamorphic fluid flow and metal transport.

Radiological and elemental composition of cryoconite and glacier mice from Vatnajökull, Iceland

Cryoconite has been demonstrated to be an efficient accumulator of some classes of contaminants on glaciers in both mountain and polar environments, however the accumulation of contaminants in cryoconite in Iceland has received very little attention to date. To understand the spatial variability of natural and anthropogenic fallout radionuclides and metals on glaciers in Iceland, we present the first study of this region including both cryoconite from three glaciers: Virkisjökull; Skaftafellsjökull; and Falljökull, together with moss balls (‘glacier mice’) from Falljökull. The cryoconite samples and glacier mice were analysed using XRF spectrometry to assess their elemental composition and gamma spectrometry to identify, and quantify, fallout radionuclides, primarily 7Be, 137Cs, 241Am, excess 210Pb, and 40K. The results revealed that the cryoconite samples had similar compositions, influenced by local geology and natural sources of volcanic ash and dust. Higher concentrations of radionuclides and heavy metals were found in both cryoconite and glacier mice compared to control samples comprising nearby proglacial sediments. In comparison to other glaciers in the Northern Hemisphere, however, cryoconite from Icelandic glaciers contains some of the lowest activity concentrations of key radionuclides. Consequently, cryoconite deposits that are released and diluted during the melt and retreat of Icelandic glaciers are unlikely to be of environmental concern following transport to proglacial areas.

Human exposure to uranium through drinking water and its detrimental impact on the human body organs.

Human exposure to high concentrations of uranium is a major concern due to the risk of developing numerous internal organ malignancies over time. In addition to the numerous attributes of uranium in the nuclear power industry, the radiological characteristics and chemical toxicity of uranium present a substantial risk to human health. This study aims to evaluate potential negative health impacts associated with the ingestion of uranium through drinking water in the Noida and Greater Noida region within the Gautam Buddha districts of Uttar Pradesh (India), due to extreme industrial revolution in this geological location. The mean concentration of uranium in drinking water of the examined area was estimated to range from 0.23 to 78.21µgl-1. The hair compartment biokinetic model is used to estimate the retention and radiological doses of uranium in distinct organs and tissues. Studies on time-dependent factors revealed variations in uranium retention, with lower levels observed in the Gastrointestinal Tract (GIT) region and higher levels on cortical bone surfaces causes the skeletal deformities. The kidney, liver, and other soft tissues (OST) exhibited a non-saturation pattern in the retention of uranium via exposure of drinking water. The age-wise non-carcinogenic and carcinogenic doses were estimated for the health hazards studies. The outcome of this study will be useful for water resource management authorities to supply safe potable water to the local residents.