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The Permian Qipan Formation (P1-2q) is the aim horizon for hydrocarbon source rocks in the piedmont area of southwestern Tarim Basin. In the present study, the depositional environment and geochemical characteristics of muddy hydrocarbon source rocks of P1-2q were systematically evaluated using total organic carbon (TOC), Rock-Eval pyrolysis, vitrinite reflectance (Ro), reflected light microscopy, main and trace element, and biomarker parameters of 167 outcrop samples and 176 core samples. The TOC of P1-2q is primarily concentrated within the range of 0.36% to 2.77%, with an average of 1.58%. This suggests that the overall evaluation of the hydrocarbon source rock is fair to good. The source rocks of P1-2q predominately contain Type III and Type II2 kerogen. The overall Tmax values of P1-2q hydrocarbon source rocks are notably elevated, with the majority exceeding 490 °C or falling between 455 °C and 490 °C. The Ro value is between 0.90% and 2.00%, indicating that the maturity has reached a high, over-mature evolutionary stage. The trace element and biomarker parameters indicate that hydrocarbon source rocks of P1-2q are predominantly slightly oxygen-rich, with a minor anoxic component. The asymmetric 'V' arrangement of the C27-C29 regular steranes indicates that the hydrocarbon parent material is predominantly derived from algae or aquatic organisms, with varying degrees of mixing with organic matter of terrestrial origin. The study of source rock geochemistry of the P1-2q makes the exploration target of the southwest depression of the Tarim Basin more accurate in the complex tectonic geological environment. [ABSTRACT FROM AUTHOR]

This chapter (Principles and Practice of X‐Ray Fluorescence Spectrometry – 1: Fundamentals of XRF and Matrix Corrections) is a contribution to the Geostandards and Geoanalytical Research Handbook of Rock and Mineral Analysis – an online textbook that is a fully revised and updated edition of the Handbook of Silicate Rock Analysis (P. J. Potts, 1987, Blackie, Glasgow). Chapter 6, Part 1 (from Section 2 of the handbook dealing with techniques for the determination of major and trace elements) considers the fundamentals of XRF spectrometry and matrix corrections in detail. Part 2 deals with wavelength dispersive and energy dispersive instrumentation. Following an introduction dealing with the analytical characteristics of XRF spectrometry, Part 1 continues with a detailed consideration of the origin and excitation of X‐ray spectra. Sub‐chapters that tackle the interaction of X‐rays with matter and the matrix effect in geological materials follow this. Part 1 is concluded with a mathematical treatment of the correction of absorption‐enhancement effects. [ABSTRACT FROM AUTHOR]

A support vector machine regression (SVMR) model that integrates data preprocessing was devised for the determination of Mo in molybdenum ores. To eliminate the negative effects of spectral fluctuations and improve the computational efficiency, the model processes original measurements through the following steps: denoising via wavelet transform smoothing (WTS), debaselining via adaptive iteratively reweighted penalized least squares (airPLS), main characteristic peak extraction, elimination of abnormal spectral data via the box plot method, and normalization via min-max scaling. In this study, 255 characteristic peaks were selected from 17,916 spectral datasets, and the total number of datasets after removing the outliers was 491. The calibration curve approach was used to establish a univariate model. The limit of detection of Mo was 0.0080 wt%. The R2 value of the calibration curve was 0.6675. Linear regression (LR) and SVMR were used to establish a multivariate analysis model. Compared to that of the calibration curve approach, the determination coefficients (RP2) of LR and SVMR increased from 0.8034 to 0.9859 and 0.9941, respectively. The range of relative errors (REP) decreased from 0.21%–67.66% to 0.48%–18.46% and 2.65%–7.44%, respectively; the mean absolute error (MAEP) was decreased from 0.0173 wt% to 0.0048 and 0.0039 wt%, respectively; and the root mean square error (RMSEP) decreased from 0.0243 wt% to 0.0065 and 0.0042 wt%, respectively. These results indicate that the integration of SVMR with data preprocessing is suitable for the determination of Mo in molybdenum ores. [ABSTRACT FROM AUTHOR]

Both the mineralogy and geochemistry of coal mine waste presents environmental and social challenges while simultaneously offering the potential source for recovery of metals, including critical raw materials (CRMs). Assessing these challenges and opportunities requires effective waste management strategies and comprehensive material characterization. This study deals with the integration of analytical data obtained from various portable sensor technologies. Infrared reflection spectroscopy (covering a wide wavelength range of 0.4 to 15 µm), and geochemical x-ray fluorescence (XRF) were utilized to differentiate between samples belonging to various geological lithologies and quantify elements of interest. Therefore, we developed a methodological framework that encompasses data integration and machine learning techniques. The model developed using the infrared data predicts the Sr concentration with a model accuracy of R2 = 0.77 for the testing dataset; however, the model performances decreased for predicting other elements such as Pb, Zn, Y, and Th. Despite these limitations, the approach demonstrates better performance in discriminating materials based on both mineralogical and geochemical compositions. Overall, the developed methodology, enables rapid and in-situ determination of coal mine waste composition, providing insights into waste composition that are directly linked to potential environmental impact, and the possible recovery of economically valuable metals. [ABSTRACT FROM AUTHOR]

Both the mineralogy and geochemistry of coal mine waste presents environmental and social challenges while simultaneously offering the potential source for recovery of metals, including critical raw materials (CRMs). Assessing these challenges and opportunities requires effective waste management strategies and comprehensive material characterization. This study deals with the integration of analytical data obtained from various portable sensor technologies. Infrared reflection spectroscopy (covering a wide wavelength range of 0.4 to 15 µm), and geochemical x-ray fluorescence (XRF) were utilized to differentiate between samples belonging to various geological lithologies and quantify elements of interest. Therefore, we developed a methodological framework that encompasses data integration and machine learning techniques. The model developed using the infrared data predicts the Sr concentration with a model accuracy of R2 = 0.77 for the testing dataset; however, the model performances decreased for predicting other elements such as Pb, Zn, Y, and Th. Despite these limitations, the approach demonstrates better performance in discriminating materials based on both mineralogical and geochemical compositions. Overall, the developed methodology, enables rapid and in-situ determination of coal mine waste composition, providing insights into waste composition that are directly linked to potential environmental impact, and the possible recovery of economically valuable metals.

To clarify the genetic mechanism for phase change of the hydrocarbon in the ultra-deep reservoirs, a case study from the Ordovician hydrocarbon in the Halahatang–Shunbei area (HSA), Tarim Basin, NW China, was conducted. The results show that the Ordovician reservoirs in the HSA are characterized as multi-phase reservoirs with a lateral co-existence of condensates, volatile-oil reservoirs, normal oil reservoirs, and heavy oil reservoirs. From north to south, there are regular variations in the geochemical characteristics of the Ordovician hydrocarbon in different blocks of the HSA, showing an increasing trend in GOR, dryness coefficients, methane contents, methane carbon isotope values, and ethane carbon isotope values, while a decreasing trend in oil densities and wax contents. Because the same Cambrian–Lower Ordovician source for the Ordovician hydrocarbon is observed and the kerogen-cracking gas is dominated in the HSA, the regular variations of the hydrocarbon phases and geochemical characteristics can be interpreted as records of biodegradation and multistage oil–gas filling rather than controlled by the source rock organofacies, oil cracking, and gas invasion. The formation mechanism of the Ordovician multi-phase reservoirs in the HSA suggests that the deep strata of the Tarim Basin hold potential for the exploration of natural gas resources.

The evaluation and monitoring of sites contaminated with heavy metals are essential for pollution remediation and prevention. In this study, we conducted geophysical and geochemical investigations at a site exhibiting heavy metal contamination downstream from an abandoned mine, with the aim of analyzing the extent of contamination and its temporal variation. We employed geophysical survey methods including electrical resistivity and induced polarization surveys of areas contaminated with heavy metals. Repeated surveys were conducted over time using the electrical resistivity method. Numerical simulations were employed to mitigate and eliminate electrical noise stemming from topography on the site. Additionally, time-lapse inversion was conducted on the resistivity data sets to analyze the changes in resistivity caused by variations in heavy metal contaminants. In the geochemical survey, soil samples were collected from the same locations as the geophysical survey, and chemical properties including pH, water content, electrical conductivity, and cation exchange capacity were analyzed. Our results showed that with the reduction of major sources of As and Zn contamination by 50%, the time-lapse electrical resistivity inversion results indicated that the resistivity of the subsurface materials increased by a factor of two. This paper demonstrated the natural reduction of the heavy metal contaminants at the site due to rainfall, aiming to comprehensively analyze the resultant alteration of both geochemical and geophysical properties. [ABSTRACT FROM AUTHOR]

Located on the Congolese (DRC) side of the Lemba depression, our study area is the part that was returned by "ex-Zaïrep", just east of the concession currently operated by Perenco rep. Open to oil and mining exploration, we brought back phosphate rock samples from the field, which were analyzed by the Commissariat Général à l'Energie Atomique (CGEA) using the ED-XRF Xepos III spectrometer. These analyses were used to characterize the geochemistry of the Kanzi and Mvuangu phosphates. The results of the Chemical Analyses (Oxides) and Chemical Elements are as follows: (1) Major oxides (%:) Al2O3 (21,21 - 17,24); SiO2 (14,85 - 30,40); P2O5 (19,48 -13,34 %) finally Fe2O3 (8,544 - 10,74 %), and other oxides with concentrations in mg/kg (MnO, ZnO, Rb2O, SrO, ZrO2, Nb2O5, Sb2O5, Ta2O5); (2) Major Chemical Elements (%): Aluminum (11.22-9.124); Silicon (6.939-14.21); Phosphate (8.5-5.823 %) and several trace metallic elements that will be exposed in another soil and sediment matrix to assess the state of the environment prior to mining and petroleum activities. The origin of these metallic elements, including heavy metals, rare earths and radionuclides, is phosphate. Phosphate rocks, such as apatite, may contain heavy metals, rare earths and radionuclides in their mineral structure. The gravity anomaly map of the Lemba sub-basin, where the phosphate sites are located, clearly shows that the phosphates of Kanzi in the south and Mvuangu in the north are not located in the central deposits, but in the upper parts of the sub-basin. These areas are potentially anticlines, which are geological structures capable of containing hydrocarbons. This study is a contribution to our knowledge of the phosphate resource in Kanzi and Mvuangu, and contribute to understanding the geological structures capable of containing hydrocarbons. It is also an important contribution in the field of geochemistry and gravimetry. [ABSTRACT FROM AUTHOR]

We address the challenges of limescale deposition and its management in urban construction sites, specifically within the Sumayil North project in Tel Aviv. Jet grouting, a method increasingly favored over conventional dewatering techniques for its minimal environmental impact and efficiency, is scrutinized for its unintended consequences on groundwater chemistry, particularly in relation to limescale formation. Our investigation centers on a dual approach: dissecting the geochemical dynamics leading to limescale deposition following jet grouting operations, and evaluating a remedial acid injection strategy implemented to counteract this phenomenon. We identify the critical factors influencing aquifer water chemistry through a detailed hydro-chemical analysis encompassing the Pleistocene Coastal Aquifer's dynamics. The study reveals that the interaction between grout components and aquifer water significantly alters groundwater pH, driving the precipitation of calcium carbonate. The subsequent implementation of a sulfuric acid injection regimen successfully mitigated limescale accumulation, restoring pumping efficiency and neutralizing pH levels. We propose a workflow to manage and prevent limescale, emphasizing preemptive measures like custom grout compositions and controlled dewatering, with strict post-intervention groundwater monitoring. This approach balances operational efficiency, infrastructure integrity, and environmental stewardship in urban construction projects interfacing with sensitive aquifer systems. [ABSTRACT FROM AUTHOR]

This paper presents an integrated geophysical and geochemical data exploration for assessing the potential presence of gold in Lokoja Sheet 247, Ajaokuta L.G.A of Kogi State, Nigeria by using interpretation of varying derivatives to delineate structural features, with a specific focus on the NE - SW direction, aligning with the regional trend. Additionally, x-ray fluorescence analysis was employed to examine samples from the study area. The interpreted aeromagnetic data unveiled a high anomalous area, prompting further geochemical investigation. X-ray fluorescence analysis indicated gold concentrations ranging up to five parts per million in certain samples, signifying potential high-grade gold mineralization in the study area. Based on the integrated geophysical and geochemical findings, it is recommended that more detailed exploration efforts be concentrated in the eastern half and northwestern portion of the study area. Notably, this research utilized x-ray fluorescence analysis, which proved effective at this stage; however, for more robust information, future exploration endeavors should incorporate advanced geochemical analyses. Moreover, follow-up ground geophysical surveys, including Induced Polarization, ground magnetic, and electromagnetic methods, are deemed necessary. [ABSTRACT FROM AUTHOR]

Measure while drilling (MWD) refers to the acquisition of real-time data associated with the drilling process, including information related to the geological characteristics encountered in hard-rock mining. The availability of large quantities of low-cost MWD data from blast holes compared to expensive and sparsely collected orebody knowledge (OBK) data from exploration drill holes make the former more desirable for characterizing pre-excavation subsurface conditions. Machine learning (ML) plays a critical role in the real-time or near-real-time analysis of MWD data to enable timely enhancement of OBK for operational purposes. Applications can be categorized into three areas, focused on the mechanical properties of the rock mass, the lithology of the rock, as well as, related to that, the estimation of the geochemical species in the rock mass. From a review of the open literature, the following can be concluded: (i) The most important MWD metrics are the rate of penetration (rop), torque (tor), weight on bit (wob), bit air pressure (bap), and drill rotation speed (rpm). (ii) Multilayer perceptron analysis has mostly been used, followed by Gaussian processes and other methods, mainly to identify rock types. (iii) Recent advances in deep learning methods designed to deal with unstructured data, such as borehole images and vibrational signals, have not yet been fully exploited, although this is an emerging trend. (iv) Significant recent developments in explainable artificial intelligence could also be used to better advantage in understanding the association between MWD metrics and the mechanical and geochemical structure and properties of drilled rock. [ABSTRACT FROM AUTHOR]

We address the challenges of limescale deposition and its management in urban construction sites, specifically within the Sumayil North project in Tel Aviv. Jet grouting, a method increasingly favored over conventional dewatering techniques for its minimal environmental impact and efficiency, is scrutinized for its unintended consequences on groundwater chemistry, particularly in relation to limescale formation. Our investigation centers on a dual approach: dissecting the geochemical dynamics leading to limescale deposition following jet grouting operations, and evaluating a remedial acid injection strategy implemented to counteract this phenomenon. We identify the critical factors influencing aquifer water chemistry through a detailed hydro-chemical analysis encompassing the Pleistocene Coastal Aquifer’s dynamics. The study reveals that the interaction between grout components and aquifer water significantly alters groundwater pH, driving the precipitation of calcium carbonate. The subsequent implementation of a sulfuric acid injection regimen successfully mitigated limescale accumulation, restoring pumping efficiency and neutralizing pH levels. We propose a workflow to manage and prevent limescale, emphasizing preemptive measures like custom grout compositions and controlled dewatering, with strict post-intervention groundwater monitoring. This approach balances operational efficiency, infrastructure integrity, and environmental stewardship in urban construction projects interfacing with sensitive aquifer systems.

This research delves into the geochemical aspects, non-isothermal thermogravimetric analysis, and model-free kinetics of oil shale samples from the Ãeltek region in Amasya, Türkiye. Shifting the focus to the core of the research, thermal and mass spectrometric analysis (TGâDTGâMS) experiments were conducted in an air atmosphere, employing three distinct heating rates of 10, 20, and 30 °C/min. The outcomes revealed two successive reaction stages: the breakdown of organic matter and mineral decomposition. In the breakdown stage, activation energy values exhibited a range of 160â163 kJ/mol, while in the mineral decomposition stage, the values varied between 208â214 kJ/mol, using model-free kinetic models.

The idea of this work is to compare the results of geochemical and statistical analyzes in the study of organic matter in extracts of oil and gas source rock. The object of the study were the samples of oil and gas source rocks of the Tutleim and Tyumen Formations, as well as oil samples of the Vikulov Formation and Jurassic and pre-Jurassic deposits in the western part of the West Siberian basin.Among the methods of statistical analysis, the principal component method and the random forest method were used. A heat map of correlations was used as visualization tools.The principal component method helped us to reveal a clear difference between the organic matter of the Tutleim and Tyumen source rocks. The random forest method and the heat map made it possible not only to identify the distinctive geochemical properties for this strata, but also reveals the geological factors of their distinction. Thus, the organic matter of Tyumen source rock turned out to be more mature and it has relatively larger contribution of terrestrial organic matter compared to the Tutleim one. The same set of methods is applied to oil-source rock correlation. The oils of the Vikulov Formation obviously originate from the Tutleim source rock. Oils of Jurassic and pre-Jurassic reservoirs have a predominant contribution of the Tutleim source rock and some similarity (up to 30 %) with the Tyumen one. Oils from the Vikulov Formations are less mature than oils from the Jurassic and pre-Jurassic rocks. This may indicate the continued migration of hydrocarbons to Jurassic and pre-Jurassic deposits and the cessation of migration in the past to the overlying Aptian–Albian Vikulov Formation. Geochemical analysis also revealed the geochemical properties responsible for the maturity of source rocks and the type of organic matter. It confirmed the conclusions made on the basis of the application of methods of statistical analysis.

This research delves into the geochemical aspects, non-isothermal thermogravimetric analysis, and model-free kinetics of oil shale samples from the Çeltek region in Amasya, Türkiye. Shifting the focus to the core of the research, thermal and mass spectrometric analysis (TG-DTG-MS) experiments were conducted in an air atmosphere, employing three distinct heating rates of 10, 20, and 30 °C/min. The outcomes revealed two successive reaction stages: the breakdown of organic matter and mineral decomposition. In the breakdown stage, activation energy values exhibited a range of 160-163 kJ/mol, while in the mineral decomposition stage, the values varied between 208-214 kJ/mol, using model-free kinetic models. [ABSTRACT FROM AUTHOR]

In the framework of the Helmholtz ARCHES project, a multitude of robots, including rovers and drones, were prepared for the autonomous exploration of a test site at the foothills of Mt. Etna, Sicily—a terrain resembling extraterrestrial locations such as the Moon. To expand the suite of tools and sensors available for the exploration and investigation of the test site, we developed a laser-induced breakdown spectroscopy (LIBS) instrument for the geochemical analysis of local geological samples. In alignment with the mission scenario, this instrument is housed in a modular payload box that can be attached to the robotic arm of the Lightweight Rover Unit 2 (LRU2), allowing the rover to use the instrument autonomously in the field. A compact Nd:YAG laser is utilized for material ablation, generating a micro-plasma that is subsequently analyzed with a small fiber-coupled spectrometer. A single-board computer controls the LIBS hardware components for data acquisition. In this study, we provide details of the ARCHES LIBS instrument implementation, report on preceding laboratory tests where the LRU2 operated the LIBS module for the first time, and showcase the results obtained during the successful ARCHES space analogue demonstration mission campaign in summer 2022 in Sicily. [ABSTRACT FROM AUTHOR]

While land transportation is crucial for social development, it also introduces various pollutants, including heavy metals, which pose risks to both the environment and human health. This issue is particularly acute in mining areas, yet research focusing on heavy metal accumulation in soils and plants along transportation routes in these areas has been limited. Addressing this gap, this study investigates soil contamination levels and heavy metal concentrations in dominant plants along a highway and railway in the vicinity of the Dexing Copper Mine, the largest open-pit copper mine in China, located in Jiangxi Province. These transportation routes are heavily utilized for ore transportation, making them critical areas for environmental monitoring. Results reveal that the primary heavy metal contaminants in the soil were Cu (84.9 to 2554.3 mg/kg), Pb (38.3 to 2013.4 mg/kg), Cd (0.1 to 46.6 mg/kg), Zn (81.3 to 875.8 mg/kg), and As (11.8 to 2985.2 mg/kg), with significantly higher concentrations found in soils adjacent to the railway compared to the highway. Specifically, for plants along the highway, Cyperus rotundus showed a significant enrichment in Cd and demonstrated a notable capacity to translocate heavy metals from its roots to aerial parts. This is evidenced by the elevated concentration of Cd in the plant's aboveground tissues (0.87 mg/kg). Notably, both the bioconcentration factor (BCF) and translocation factor (TF) values exceeded 1, ranging from 1.07 to 3.62. Contrastingly, despite the elevated heavy metal concentrations in soils adjacent to the railway, plants in these areas did not exhibit hyperaccumulation characteristics. The unique behavior of Cyperus rotundus in accumulating and translocating Cd underscores its potential role in phytoremediation, particularly in the context of environmental management for areas impacted by mining activities, such as those surrounding China's largest copper mine. [ABSTRACT FROM AUTHOR]

The distribution characteristics and main controlling factors of hydrocarbon phases in deep strata from petroliferous basins are important for the evaluation of oil–gas resources and decision-making regarding exploration. The distribution characteristics and controlling factors of the Ordovician hydrocarbon phases are systematically analyzed in the Tazhong I block, Tarim Basin, NW China. The results show that the Ordovician reservoirs in the Tazhong I block are characterized as multi-phase reservoirs with a lateral co-existence of condensates, normal oil reservoirs, and heavy oil reservoirs. From east to west, gas-rich in the fault belt and oil-rich in the platform area are presented. Meanwhile, there are regular variations in the geochemical characteristics of the Ordovician hydrocarbon, showing decreasing trends in the gas/oil ratio (GOR), wax contents, dryness coefficients, methane contents, and methane carbonate isotope values (δ13C1) and an increasing trend in oil densities. Because the same Cambrian–Lower Ordovician source for the Ordovician hydrocarbon is observed in the Tazhong I block, the regular variations in the hydrocarbon phases and geochemical characteristics can be interpreted as records of gas invasion, biodegradation, multi-stage filling, thermal cracking, and thermochemical sulfate reduction (TSR) rather than controlled by the source rock organofacies. This indicated that different kinds of secondary processes for a diversity of the hydrocarbon phase can appear in one region. Our re-construction of the Ordovician hydrocarbon accumulation model in the Tazhong I block encourages future exploration to target gas reservoirs in the fault belt and oil reservoirs in the platform area. [ABSTRACT FROM AUTHOR]

The study assessed petroleum systems in the southern Bida Basin, Nigeria, focusing on the Cretaceous sediments. Reservoirs comprise Lokoja and Patti Formation sandstones, while shales, claystone, and siltstone serve as source rocks and stratigraphic traps/seals. Detailed studies delineating the key elements of the petroleum systems in the basin have not been conducted due to a lack of subsurface data. The goal of the current study was to use field observations, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and geochemical and geomechanical data to evaluate key components of petroleum systems in the southern Bida Basin. The results presented in this investigation are intended to attain specific objectives, especially those lacking in the basin's study sections. Petrophysical analysis revealed that the Lokoja Sandstone has porosity of 37%–39.5% and moderate permeability of 23.22–42.29 mD. The Patti Formation sandstone reservoirs exhibited high porosity (38%–42%) and moderate to good permeability (31.54–66.48 mD), suggesting good potential reservoirs. SEM results revealed intragranular pores and micro-fractures in the Patti Shale, whereas the sandstone reservoirs in the Lokoja and Patti formations displayed fractures, facilitating hydrocarbon migration. Quartz was the dominant mineral in the sandstone units of both formations. XRD analysis revealed that brittle and clay minerals influenced the microstructure of Patti Shale. Geochemical analysis indicated promising petroleum potential in the Patti Shale, with a total organic carbon (TOC) content of 1.87 wt%, free hydrocarbon from kerogen (S1) of 0.41 mg/g, hydrogen index (HI) of 0.75 mg HC/g TOC, and production index (PI) of 0.17. The Patti and Lokoja formations' shale, claystone, and siltstone exhibited sealing potential, with a plasticity index of 24–35 and coefficient permeability of 2.8 × 10−4- 3.6 × 10−4 cm/s. Field studies, XRD, geochemical data, and geomechanical index values have confirmed the key components of the petroleum system, which in turn facilitate hydrocarbon generation, migration, accumulation, and entrapment in the basin.

This paper presents an integrated geophysical and geochemical data exploration for assessing the potential presence of gold in Lokoja Sheet 247, Ajaokuta L.G.A of Kogi State, Nigeria by using interpretation of varying derivatives to delineate structural features, with a specific focus on the NE – SW direction, aligning with the regional trend. Additionally, x-ray fluorescence analysis was employed to examine samples from the study area. The interpreted aeromagnetic data unveiled a high anomalous area, prompting further geochemical investigation. X-ray fluorescence analysis indicated gold concentrations ranging up to five parts per million in certain samples, signifying potential high-grade gold mineralization in the study area. Based on the integrated geophysical and geochemical findings, it is recommended that more detailed exploration efforts be concentrated in the eastern half and northwestern portion of the study area. Notably, this research utilized x-ray fluorescence analysis, which proved effective at this stage; however, for more robust information, future exploration endeavors should incorporate advanced geochemical analyses. Moreover, follow-up ground geophysical surveys, including Induced Polarization, ground magnetic, and electromagnetic methods, are deemed necessary.

The geochemical parameters discussed in this paper are based on the analysis of twelve outcrop carbonaceous samples, mainly black shales, using X-Ray Fluorescence (XRF) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) techniques. These samples are representative of the Charu, Sagor, and Permian formations. The aim of this study is to define and discuss their characteristics, the distribution abundance of major and minor elements, investigate the dominant mineralogical composition, and reconstruct the depositional environment for these sediments. The bulk chemical results showed that the average values of the major elements are 65.83%, 64.82%, and 71.4% SiO?; 18.27%, 22.2%, and 15.66% Al?O?; 1.53%, 0.99%, and 2.49% Fe?O?; and 4.06%, 6.25%, and 3.66% K?O for the Charu, Sagor, and Permian formations, respectively. The minor elements recorded values of 524.4 ppm, 758.8 ppm, and 446.3 ppm Ba; 366 ppm, 399.3 ppm, and 257.3 ppm Rb; 88 ppm, 67.3 ppm, and 47.3 ppm Sr; and 308 ppm, 288.8 ppm, and 327 ppm Zr for the Charu, Sagor, and Permian formations, respectively. The major oxides reflect the dominant mineralogical composition of quartz and other silicate minerals (e.g., illite, kaolinite, smectite) and a deficiency in carbonates. The high Rb/K ratio suggests a brackish marine environment or rapid deposition that prevented equilibrium between Rb and K in these shales. The high Rb/Sr ratios of 4.16, 5.89, and 5.44 for the Charu, Sagor, and Permian formations, respectively, are possibly attributed to the low Sr content due to reducing conditions prevailing during the deposition of these sediments.

The Permian Qipan Formation (P1-2q) is the aim horizon for hydrocarbon source rocks in the piedmont area of southwestern Tarim Basin. In the present study, the depositional environment and geochemical characteristics of muddy hydrocarbon source rocks of P1-2q were systematically evaluated using total organic carbon (TOC), Rock-Eval pyrolysis, vitrinite reflectance (Ro), reflected light microscopy, main and trace element, and biomarker parameters of 167 outcrop samples and 176 core samples. The TOC of P1-2q is primarily concentrated within the range of 0.36% to 2.77%, with an average of 1.58%. This suggests that the overall evaluation of the hydrocarbon source rock is fair to good. The source rocks of P1-2q predominately contain Type III and Type II2 kerogen. The overall Tmax values of P1-2q hydrocarbon source rocks are notably elevated, with the majority exceeding 490 °C or falling between 455 °C and 490 °C. The Ro value is between 0.90% and 2.00%, indicating that the maturity has reached a high, over-mature evolutionary stage. The trace element and biomarker parameters indicate that hydrocarbon source rocks of P1-2q are predominantly slightly oxygen-rich, with a minor anoxic component. The asymmetric ‘V’ arrangement of the C27-C29 regular steranes indicates that the hydrocarbon parent material is predominantly derived from algae or aquatic organisms, with varying degrees of mixing with organic matter of terrestrial origin. The study of source rock geochemistry of the P1-2q makes the exploration target of the southwest depression of the Tarim Basin more accurate in the complex tectonic geological environment.

Peatlands, as an important carbon sink, store a large amount of atmospheric carbon that is vulnerable to becoming a carbon emission source due to the disturbance of the peat layer by natural and anthropogenic processes. The Kuan Kreng peat swamp forest is the second largest peatland in Thailand and is in coastal wetland serving for carbon stock in the subsurface. To assess carbon stock in peatland, the thickness and distribution of the peat layer are necessary. This study determines physical and chemical characteristics of the peatlands in the coastal wetland, southern Thailand by conventional core study and geophysical surveys, including ground penetrating radar (GPR) and electrical resistivity imaging (ERI). There is a significant relationship between chemical and physical properties from the peat layer, which is useful to approximately predict the physical properties and peat layers in the geophysical profiles. The resistivity profiles exhibit high resistivity response, peat between 21.9 and 145.0 ohm-m, interpreted as the peat layers in the shallow subsurface. The high resolution GPR profiles provide an average GPR velocity in peat of 0.040 m/ns and a relative dielectric constant of 54.9 for the peat layers. The peat layer is characterized by a high amplitude of reflection in the GPR profiles. The thickness of the peat layers was estimated from the geophysical surveys and the drilling cores having an average thickness of 18 cm. Average values of bulk density (0.19 g/cm3) and TOC (31.18 wt. %) from the drilling core samples are used to calculate the carbon density in the peat layers giving a result of 59.24 Kg C/m3. Hence, the carbon stock at the Kuan Kreng peat swamp forest is estimated at least 7.53 megaton carbon, which is much higher than aboveground biomass carbon in this area. The innumerably high amount of carbon stock could raise awareness of peatland disturbances. [ABSTRACT FROM AUTHOR]

The Cretaceous limestone facies from Yandev section in the central Benue Trough, Nigeria constitutes parts of the potential reservoirs and sources rocks for petroleum prospects in the basin. The central Benue Trough is the least studied basin among its contemporaries due to lack of subsurface data. Detailed mineralogical, facies analysis and diagenesis of these carbonate rocks in the basin have not received significant study. The aim of this study was to employed multifaceted methodology such as sedimentological, facies analysis petrographic and geochemical approaches which was lacking in previous research in the trough. The sedimentological analysis was done to evaluate fabrics grain sizes, and lithology types. For petrographic analysis, thin sections were prepared and examined under a petrographic microscope and categorized according to Dunham's classification. Geochemical analysis involved X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscope - energy dispersive X-ray spectroscopy (SEM-EDX) techniques to unveil mineralogical, oxide, and elemental compositions. The sedimentological results revealed light to dark grey medium to fine-grained limestone facies with intercalation of dark grey shales and siltstones. The XRD mineralogy data, revealed calcite (60.00 - 64.10%), quartz (14.30 - 51.00%), albite (12.30 - 19.00%), and chlorite (6.30 - 8.10%). Microfacies results revealed distinct sandy bioclastic wackstone and sparitic intraclastic packstone, as well as micritic intraclastic wackestone and sparitic bioclastic packstone. SEM images highlighted the intricate composition, including elongated structures, whites and dark spots suggesting varying conditions of deposition. Elemental analysis through EDX emphasized significant proportions of carbon, oxygen, sodium, potassium, calcium, silicon, aluminum, iron, and magnesium. Based on sedimentological, biofacies, lithofacies and geochemical evidence we infer that the carbonate sediments were mainly deposited in a shallow marine depositional environment (inner to outer neritic). [ABSTRACT FROM AUTHOR]

Purpose: Although the formation mechanism of the megadunes in the Badain Jaran Sand Sea has received considerable research attention, their provenance and sand accumulation processes are still poorly understood. Therefore, this study aims to identify the provenance of the megadunes and clarify the spatial and temporal characteristics of their source supply processes. Materials and methods: We collected megadune sands in the Badain Jaran Sand Sea and sediments from their potential source regions (i.e., the Heihe-Altay alluvial fan, Heihe River, Beida-Yabrai alluvial fans, and Gulunai-Guaizi dry lakes). We analyzed the geochemical compositions of these sediments using X-ray fluorescence spectrometer. Source identification was conducted using robust K/Ba and K/Rb ratios and the multidimensional scaling (MDS) method. Based on fluvial-aeolian system distribution and comparison with drilling cores, the spatial and temporal source supply processes of the megadunes were determined. Results and discussion: The K/Ba vs. K/Rb biplot showed that the Heihe-Altay alluvial sediment, Heihe River fluvial sand, and the Beida-Yabrai alluvial sediment samples were similar to the sand in the megadunes. Similarly, MDS result showed that these sources had similarities to the megadune sand, indicating that they were the sources of the megadune sand. Based on the distribution of fluvial-aeolian systems, we conclude that the sediments from the Qilian Mountains and Altay Mountains were first mixed in the Heihe River, after which they were sorted and transported by the northwest wind to the megadune field. The Beida-Yabrai Mountains delivered source sediments to the sand sea via short-lived runoff episodes and southeast winds, which were not as significant as those previously described. These sands finally built megadunes in two directions, namely from the northwest to the southeast and its opposite direction due to the prevailing northwest wind and local air circulation from the slipface. By comparing drilling cores from within and near the sand sea, we found that fluvial sediments were prevailing in the lower reaches of the Heihe River during Marine Isotopic Stage (MIS) 4 and MIS 2, when the megadunes rapidly migrated. However, the Heihe-Altay alluvial fan formed since the Late Pleistocene when the sand sea began to form, indicating a more extended source supply history. Conclusions: Our results indicated that the Heihe-Altay alluvial sediments, the Heihe River fluvial sand, and the Beida-Yabrai alluvial sediments were the sources of the megadune sand. The sediments transported to the dune field by fluvial-aeolian systems at the sand sea scale and accumulated on the megadunes from both windward and leeward directions at the individual dune scale. Temporally, the Heihe-Altay alluvial fan may be a continuous source of sediments for the development of the megadunes, and the Heihe River may have contributed to their rapid migration during MIS 4 and MIS 2. [ABSTRACT FROM AUTHOR]

Coral reefs are highly diverse and productive ecosystem in the ocean that provides various goods services to human and environment. Located within the renowned 'Coral Triangle' region, Malaysia is one the thriving countries in Southeast Asia that possess rich marine resources and coral reefs. Like other coral reef around the world, coral reefs in Malaysia are exposed to multiple threat that jeopardize their well-being. Those relying on these ecosystems may face severe consequences if they are lost. In recent decades, research on characterizing modern coral reefs has increased in Malaysia, including identifying key species and their distribution, understanding the factors that control coral growth and assessing the impacts of environmental stressors on reef health. This study is aimed to provide an overview of the current state of knowledge of modern coral characterization studies conducted in Malaysia. It presents the distribution maps of these coral reef studies conducted throughout Malaysia and discusses the techniques employed to characterize them. Most of the studies was conducted in South China Sea, particularly in East Coast of Peninsular Malaysia with Tioman Island, Pahang being identified as having the greatest number of studies. And, visual assessment have the higher frequency of use in characterizing Malaysia coral reef. Going forward, future studies in Malaysia should continue to explore others Malaysia reef, and techniques for characterizing coral reefs, while also conduct more studies in locations with limited research. These studies could have served as foundation resource for future conservation efforts in the face of ongoing threat and challenges. [ABSTRACT FROM AUTHOR]

Pensacola Dam, operated by the Grand River Dam Authority (GRDA), is a multiple-arch buttress dam constructed in 1940. The dam has little or no existing geophysical reports on the integrity of the dam foundation rock and even less knowledge at depth. Visual inspection indicated evidence of seepage at some arches of the dam. As a pilot study, we conducted a suite of geophysical surveys inside two arches (Arch-16 and Arch-17) and a part of the downstream berm to characterize the dam foundation rock, delineate seepage zones, and identify the most appropriate geophysical methods for temporal monitoring of the dam's conditions. The geophysical methods included electrical resistivity tomography (ERT), self-potential (SP), multichannel analysis of surface waves (MASW), compressional (P)-wave refraction, and shear (S)-wave reflection. Water samples were collected for geochemical analysis to investigate the source of the seepage flow inside Arch-16. The geophysical results characterized the dam foundation rock into an unsaturated limestone and chert overlying a water-saturated limestone and chert. The ERT profiles indicated that groundwater is rising inside the arches and significantly dropping under the downstream berm, which can be due to the uplift pressure beneath the dam base. Zones of high seepage potential were detected near the buttress walls of the two surveyed arches, which may be related to previous blasting, excavation of the dam foundation, concrete placement, or improper grouting. The geochemical analysis of water samples taken from the artesian wells inside Arch-16 and the Grand Lake revealed different chemical compositions, suggesting that the source of water could be a mixture of groundwater and lake water or lake water interacting with rock and reaching the surface through fractures; however, more sampling and further analysis are required to ascertain the source of the seeps. This study showed that the ERT, SP, and S-wave reflection methods have effectively characterized the dam foundation rock and seepage zones beneath the arches. The study provided a better understanding of the conditions of the dam foundation rock, evaluated the utilized geophysical methods, and determined the optimum geophysical methods that can be used for the characterization and monitoring of the subsurface conditions along the entire length of the dam. In this study, we have demonstrated that the integration of effective geophysical surveys and geochemical analysis yielded optimum results in solving a complex dam safety problem. This strategy promotes the best practice for dam safety investigation. [ABSTRACT FROM AUTHOR]

Peatlands, as an important carbon sink, store a large amount of atmospheric carbon that is vulnerable to becoming a carbon emission source due to the disturbance of the peat layer by natural and anthropogenic processes. The Kuan Kreng peat swamp forest is the second largest peatland in Thailand and is in coastal wetland serving for carbon stock in the subsurface. To assess carbon stock in peatland, the thickness and distribution of the peat layer are necessary. This study determines physical and chemical characteristics of the peatlands in the coastal wetland, southern Thailand by conventional core study and geophysical surveys, including ground penetrating radar (GPR) and electrical resistivity imaging (ERI). There is a significant relationship between chemical and physical properties from the peat layer, which is useful to approximately predict the physical properties and peat layers in the geophysical profiles. The resistivity profiles exhibit high resistivity response, peat between 21.9 and 145.0 ohm-m, interpreted as the peat layers in the shallow subsurface. The high resolution GPR profiles provide an average GPR velocity in peat of 0.040 m/ns and a relative dielectric constant of 54.9 for the peat layers. The peat layer is characterized by a high amplitude of reflection in the GPR profiles. The thickness of the peat layers was estimated from the geophysical surveys and the drilling cores having an average thickness of 18 cm. Average values of bulk density (0.19 g/cm3) and TOC (31.18 wt. %) from the drilling core samples are used to calculate the carbon density in the peat layers giving a result of 59.24 Kg C/m3. Hence, the carbon stock at the Kuan Kreng peat swamp forest is estimated at least 7.53 megaton carbon, which is much higher than aboveground biomass carbon in this area. The innumerably high amount of carbon stock could raise awareness of peatland disturbances.

The well-known Late Neolithic tell-like settlement of Öcsöd-Kováshalom on the Great Hungarian Plain gained a completely new context when a triple enclosure consisting of segments (hence the name ‘pseudo-ditch’) was discovered in 2018. Followed by two small excavation campaigns, this paper gives account of the construction stages, various digging and filling actions, of the chronology and of the structured deposits that marked the closing event of these long-lasting communal activities. A comparison with European Neolithic enclosures supports the interpretation on the diversity of the numerous ditch systems, and do not allow any generalizing views – it rather speaks for the freedom of local communities in their choices within their respective cultural frameworks.

The Cenomanian Sarvak oil reservoirs are distributed over large areas of the Persian Gulf basin. The purpose of this study is analyzing the geochemical characteristics of the Sarvak oil reservoirs and their inter-relationships in the Persian Gulf, classification of the Sarvak oil samples and investigation of the possible causes of the genetic difference in oil families. In the previous studies, limited samples of Sarvak oil reservoir in scarce oilfields were studied individually and local interpretations are made accordingly. The current study employs a more complete set of geochemical from the Iranian part of Persian Gulf and regional interpretations are drawn. To achieve this goal, the geochemical data of 41 oil samples from 10 oilfields were collected and assessed based on gas chromatography (GC), gas chromatography–mass spectrometry (GC–MS), and stable carbon isotope analysis. It was demonstrated with the evaluations that the oils accumulated in the Upper Cretaceous Sarvak reservoirs in the Persian Gulf basin originate from different source rocks. The oil samples are genetically classified into four oil families based on the similarities and differences of parameters related to the depositional environment-dependent parameters using hierarchical cluster analysis (HCA), star diagram, and stable carbon isotope diagram. The source rocks were mainly deposited in anoxic marine carbonate environments. The thermal maturity of the oils was evaluated using steranes and trisnorhopanes. Oil families 2 and 4 (located at the center of the Persian Gulf) have the highest thermal maturity compared to the other samples; in contrast, oil family 1 (located at the west of the Persian Gulf) has the lowest thermal maturity. The possible source rocks of oil family 1 and family 3 (located at eastern Persian Gulf) using C28/C29 steranes are the upper Cretaceous successions; in contrast, the possible source rocks of oil families 2 and 4 are the upper Triassic and Lower Jurassic formations. Results of the study show a high similarity between the oils of families 2 and 4, which are located at the center of the Persian Gulf; these results also recognize the significant difference between these two oil families and oil families 1 and 3. The significant issue raised in this study is to find out the reason for this difference. The structural analysis of the central Persian Gulf shows that huge vertical faults created by salt domes intrusion provided the migration pathways for trapping oil in Sarvak reservoirs. The oils of the Surmeh, Fahliyan, and Dariyan reservoirs have migrated upwards through these faults to be trapped in the Sarvak Formation across the central Persian Gulf. [ABSTRACT FROM AUTHOR]

The aim of this study is to characterize the sediments of the coastal area of Bibione and the Baseleghe Lagoon (Province of Venice, Italy). The characterization includes the assessment of particle size distribution, carbonate content, composition of major oxides, and heavy metal concentrations. The results indicated that the sediments primarily consisted of carbonate but showed significant heterogeneity in both composition and grain size within the different environments of the Bibione coastal area. Carbonate content decreased from the beach to the seabed, which does not appear to be solely influenced by variations in sediment grain size. This finding has potential implications for the Bibione area's coastal erosion processes and sediment quality. Significant differences in grain size and composition were observed between the mouth and the inner region in the lagoon area. The textural characteristics of the sediments in the inner part of the lagoon make it particularly vulnerable to pollution, with potential environmental and economic consequences. Different pollution indices have indicated the presence of heavy metal contamination in both the coastal and, especially, the lagoon area. The source of these metals appears to be predominantly natural, although there may be some contribution from anthropogenic sources for certain metals. However, the comparison of the metal concentrations in the samples with the limits set by the Italian legislation showed that the sediments were still of good quality. [ABSTRACT FROM AUTHOR]

Current knowledge concerning the introduction of shipboard artillery in Europe is limited. A small, muzzle-loading cast copper-alloy gun recovered off Marstrand on the west coast of Sweden may, however, provide some important leads regarding this development. Radiocarbon analysis of a piece of cloth from the powder chamber, possibly the remains of a cartouche, suggests a date for the cannon in the fourteenth century, making it probably the earliest example of European shipboard artillery found so far. In this paper we give an account of our recent investigations of this important find, which also include a geochemical analysis of the metal used for the casting of the gun. [ABSTRACT FROM AUTHOR]

Numerous present-day hot springs in the Sulawesi region are divided into two, generally associated with non-volcanic and tectonics geothermal systems, only a small number are associated with active volcanoes, but most do not yet have data to support their utilization. Here we have conducted research at Makula Hot Springs South Sulawesi, the method used is combined geochemical analysis with an estimation of subsurface temperature by using the geothermometer at three sites at Makula Hot Springs. The percentage values of HCO³ˉ, Clˉ, and SO₄²ˉ ion content in hot water samples were analyzed, indicating that the hot springs area was included in the chloride water type. While the results of the estimation of subsurface temperature by using the geothermometer Na - K from the three sites each show the following temperatures: Site I is 124.69℃, Site II is 122.65℃, and Site III is 114.75℃. All sites result in estimations suggested including the low enthalpy which has a temperature limit of <125℃. Furthermore, using the geothermometer Na - K - Mg is known, and the hot springs in the area are included in the partial equilibrium. Geothermal energy in the study area is used for public swimming baths, the development of a tourist attraction, and potentially for a power plant. However, it is still necessary to investigate the geothermal characteristics to maximize the utilization of the hot springs in this area. [ABSTRACT FROM AUTHOR]

In the framework of the Helmholtz ARCHES project, a multitude of robots, including rovers and drones, were prepared for the autonomous exploration of a test site at the foothills of Mt. Etna, Sicily—a terrain resembling extraterrestrial locations such as the Moon. To expand the suite of tools and sensors available for the exploration and investigation of the test site, we developed a laser-induced breakdown spectroscopy (LIBS) instrument for the geochemical analysis of local geological samples. In alignment with the mission scenario, this instrument is housed in a modular payload box that can be attached to the robotic arm of the Lightweight Rover Unit 2 (LRU2), allowing the rover to use the instrument autonomously in the field. A compact Nd:YAG laser is utilized for material ablation, generating a micro-plasma that is subsequently analyzed with a small fiber-coupled spectrometer. A single-board computer controls the LIBS hardware components for data acquisition. In this study, we provide details of the ARCHES LIBS instrument implementation, report on preceding laboratory tests where the LRU2 operated the LIBS module for the first time, and showcase the results obtained during the successful ARCHES space analogue demonstration mission campaign in summer 2022 in Sicily.

The distribution characteristics and main controlling factors of hydrocarbon phases in deep strata from petroliferous basins are important for the evaluation of oil–gas resources and decision-making regarding exploration. The distribution characteristics and controlling factors of the Ordovician hydrocarbon phases are systematically analyzed in the Tazhong I block, Tarim Basin, NW China. The results show that the Ordovician reservoirs in the Tazhong I block are characterized as multi-phase reservoirs with a lateral co-existence of condensates, normal oil reservoirs, and heavy oil reservoirs. From east to west, gas-rich in the fault belt and oil-rich in the platform area are presented. Meanwhile, there are regular variations in the geochemical characteristics of the Ordovician hydrocarbon, showing decreasing trends in the gas/oil ratio (GOR), wax contents, dryness coefficients, methane contents, and methane carbonate isotope values (δ13C1) and an increasing trend in oil densities. Because the same Cambrian–Lower Ordovician source for the Ordovician hydrocarbon is observed in the Tazhong I block, the regular variations in the hydrocarbon phases and geochemical characteristics can be interpreted as records of gas invasion, biodegradation, multi-stage filling, thermal cracking, and thermochemical sulfate reduction (TSR) rather than controlled by the source rock organofacies. This indicated that different kinds of secondary processes for a diversity of the hydrocarbon phase can appear in one region. Our re-construction of the Ordovician hydrocarbon accumulation model in the Tazhong I block encourages future exploration to target gas reservoirs in the fault belt and oil reservoirs in the platform area.

The Karibumba region, in the Mesoproterozoic Kibaran chain, is one of the least geochemically and metallogenically known regions of Kivu. Moreover, the Kibaran chain is geochemically characterized by valuable content of tin (Sn), tantalum (Ta), niobium (Nb), tungsten (W), lithium (Li), gold (Au), and rare earth elements (REE). With the belonging of Karibumba in this chain, it is likely that valuable occurrences of these elements can be found in this entity. In addition, these metals and rare earth elements are largely used nowadays by modern industries and green technologies. This increases even more and in an exponential way the demand for these metals. It is to constrain the geochemical and metallogenic aspects that this study was carried out in the Karibumba area in the territory of BENI, eastern Democratic Republic of Congo (DRC). To achieve this, geological studies and fieldwork allowed to collect samples which were geochemically analysed for trace element. These samples were selected based on petrographic facies variation. Trace elements were determined by a combination of X-ray fluorescence spectrometry (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). Results revealed that, the only mineralization identified with certainty in the Karibumba area is gold. The other elements analyzed showed grades lower than or comparable to the Clarkes and constitute the geochemical background of the area. The anomalous tin content in sample JM01 and the significant negative correlation between gold and silver raise the need for further study in the area. This would identify the nature of the stanniferous anomaly found and cross-check the surprising negative correlation between gold and silver. [ABSTRACT FROM AUTHOR]

Large-scale layered intrusions of a peridotite–pyroxenite–gabbronorite complex, to which Cr, Ni, Cu, and PGE deposits and ore occurrences are confined, were emplaced into the Baltic paleocontinent 2.50–2.45 Ga. Layered intrusions in the Monchegorsk Ore District, including the Monchepluton and Imandra–Umbarechka Complex, as well as the gabbro-anorthosite complex of the Main Ridge, were analyzed earlier geochemically and isotopically. In the present paper, the authors analyze layered intrusions in the Kola region (Mount Generalskaya) and Karelia (Kivakka, Kovdozero, and the Burakovsky Pluton). The primary composition of mantle magmas for the layered intrusions is assumed to be identical to that of the komatiitic basalts making up the volcanogenic units of the Vetreny Belt and the Imandra–Varzuga zone. A general model for the formation of layered intrusions includes superplume uplift in the early Paleoproterozoic, the generation of mantle magmas and their injection into the lower portion of the earth crust, the formation of deep-seated and intermediate magma chambers, and the intense contamination of the granulite–metamorphic complex followed by the generation of magma chambers provoked by single or multiple injections. [ABSTRACT FROM AUTHOR]

The increase in groundwater salinity of the two major dumpsites in Sierra Leone has been a major concern for stakeholders. Therefore, this study employed geochemical and stable water isotope analyses to investigate the factors controlling groundwater salinity. The proportional sources of the groundwaters were also evaluated using the Bayesian isotope mixing model. The geochemical analysis showed that the groundwater chemistry in the Granvillebrook dumpsite is controlled by water–rock interaction and evaporation while that of the Kingtom is dominated by water–rock interaction and precipitation. The biplot of deuterium (δ2H) versus oxygen (δ18O) composition relative to the global meteoric water line confirms that the groundwaters of the study areas are of meteoric origin. The linear plot of electrical conductivity versus δ18O depicts that mineralization is the major factor impacting the groundwater salinity in the study areas. The stable isotope mixing model in R (SIMMR) suggests that 96.5% of the groundwaters in the study areas are recharged by precipitation while only 3.5% originated from surface water. The SIMMR model also depicts that groundwaters in the Granvillebrook dumpsite have been bridged by leachate (33.0%) and domestic wastewater (15.2%) while for the Kingtom dumpsite, 13% and 21.5% are contaminated by leachate and domestic wastewaters. Contrary to other previous studies, this research confirms the feasibility of using the Bayesian isotope mixing model to quantify the factors influencing groundwater salinity. [ABSTRACT FROM AUTHOR]

Heavy metal accumulation in aquatic environments is a global problem as it affects the quality of sediments and aquatic life. Therefore, this study examines the geochemical composition of heavy metals and their relationships, as well as their sources by applying multivariate statistical techniques to the geochemical content of the soil in the Gumusler Dam in central Turkey. The area is dominated by Paleozoic to Quaternary-aged igneous and metamorphic rocks. Average concentrations of all the major elements in terms of their abundance in descending order are as follows: SiO2, CaO, Al2O3, Fe2O3, MgO, K2O, TiO2, MnO, and Na2O. This suggests that SiO2 is the dominant major element in the soils. The contents of heavy metals have been found to vary in the following order: Strong positive correlations have been found among the following major elements: SiO2, CaO, MgO, TiO2, Ni, Rb, Pb, Zn, and As. According to the result of the principal component analysis using the extraction criterion, six factors were found to have an eigenvalue > 1, and they were found to explain 81.854% of the total variance of the dataset. All these factors reveal that the lithogenic effect and base metal mineralization are the two main sources of heavy metals in the sediments. Also, the results of the factor analysis were confirmed by hierarchical cluster analysis, which also yielded four clusters with similar element clusters. Regression analysis also confirmed that the host rocks and base metal mineralization in the area directly affect the sediment geochemistry in the dam. [ABSTRACT FROM AUTHOR]

In this study the results of geochemical and typological analysis of late Neolithic settlement Aknashen (1st half of the 4th millennium BC) are presented. The excavations in Aknashen have started in 2004 by Armenian-French expedition under the direction of R. Badalyan. Totally 50000 obsidian objects were found during the excavation. The subject of this study are the whole lithics (2035 objects) excavated in 2015 from 1st, 2nd and 3rd horizones of 9 to 12 trenches. The material was first subjected to typological and technical- morphological analysis. Then from the undisturbed Neolithic context 118 obsidian objected were selected which were subjected for Portable X-Ray flourecense analysis to determine their geochemical features and to attribute them to their sources. [ABSTRACT FROM AUTHOR]

The article presents materials enabling to reconstruct the paleogeographic background of the development of the population of the Volga region steppe in the Neolithic and Eneolithic periods. The relevance of the study comes from the need to develop issues of natural and climatic factors influence on the development of cultures. The novelty is determined by the fact that the research presents materials of the 2014–2019 surveys for the settlement of Oroshaemoe I. The purpose of the article is to reconstruct the paleogeographic background at the time of interest. The tasks of the study also include identification of the chronological framework, reconstruction of natural and climatic conditions, and determination of the faunal component. In order to achieve these goals, archaeological, palynological and geochemical, radiocarbon and faunistic methods were used. The settlement of Oroshaemoe I is characterized by multi-layers and stratification. The site shows successively located layers of the Orlov, Caspian and Khvalynsk cultures, separated by sterile ones. In addition to ceramic and stone implements, faunal remains were found in the cultural layers which makes it possible to identify the species of animals at different stages of the Neolithic-Eneolithic of this region. Clear chronological frameworks are defined for all complexes. For the first time in recent years, the results of spore-pollen analyses were obtained for all cultural layers. An additional source was the results of geochemical analysis for this site. Certain periods of improvement and deterioration of the climatic situation are traced which influenced the vegetation cover of this area. The results of the analysis allow us to conclude that throughout the entire period the vegetation in the surrounding area was similar to modern dry steppes (semi-deserts). An increase in aridity is recorded at a later stage in the development of the Orlov culture. The driest climatic conditions existed during the formation of the Caspian layer; and during the formation of the Khvalyn layer the amount of precipitation began to increase. This resulted in changes in life activity in the Late Stone Age and the Early Metal Age.

The protection zones or capture zones of springs in desert environments can be hard to identify, but they are critical to spring protection. Most springs fed by regional aquifers are susceptible to contamination and groundwater development. The U.S. Environmental Protection Agency has established hydrogeologic mapping methods to delineate protection zones for springs. However, it is often difficult to determine a regional aquifer system's flow pattern with this technique alone, and the use of these methods is not conducive to efficient groundwater management. Particle tracking analysis using a well-conceptualized and calibrated numerical model for the three-dimensional groundwater flow domain feeding a given group of springs can help facilitate the identification of spring capture zone boundaries. Building upon this basis, a multifaceted approach was developed to define clear boundaries of the capture zones for the springs in the Furnace Creek, Ash Meadows, and the Muddy River areas in the southern Great Basin, USA. Capture zones were first delineated from inverse particle tracking and Hydrologic Unit 12 watersheds. Afterwards, they were adjusted based on water budgets, geology, and hydrologically significant faults. Finally, a geochemical analysis of the groundwater chemistry and isotopic data was conducted to verify the extent of each spring capture zone. This multifaceted approach adds confidence to the new delineations.

As Lower Cretaceous "Vigla" shales have been suggested as one of the main source rocks for the Ionian Basin in Greece, a geochemical analysis was performed for "Vigla" shales in Kastos Island and the Araxos peninsula, far from the already studied areas. Results, based on Rock-Eval VI analysis, sample fractionation, and biomarkers analysis, showed that the studied rocks could be of low production capacity, are type II/III of kerogen, and can produce liquid and gas hydrocarbons for Kastos Island. Organic matter (total organic carbon-TOC 0.02–3.45%) of the studied samples is thermally immature, in the early stages of diagenesis, and was accumulated in an anoxic environment. Additionally, the geochemical analyses confirmed the combination of marine and terrestrial origin of the organic matter. On the other hand, TOC (0.01–0.72%) from the Araxos peninsula shows fair oil potential and type IV kerogen. The results based on the Odd–Even Predominance, OEP (27–31), OEP (2), and OEP (1), valued for samples AG1, AG2, AG5, and AG6, indicated an anoxic deposition environment. As the Ionian Basin was sub-divided into three sub-basins (internal, middle, and external) during its syn-rift evolution, different depositional conditions were developed from one sub-basin to the other, with different sedimentary thicknesses within the same sub-basin or among different sub-basins and with different amounts of TOC. The fact that there is a great difference in geochemical indices between the two studied areas during the same period suggests that probable different depositional conditions could exist. It seems that the richness in Kastos Island could be related to the neighboring Apulian Platform, whereas the poorness in the Araxos peninsula could be related to the Gavrovo platform, or the differences could be related to restrictions produced regions. The comparison with previous studies indicates that different quality and quantity of organic matter could be accumulated either within the same sub-basin or from one sub-basin to the other. [ABSTRACT FROM AUTHOR]

Pensacola Dam, operated by the Grand River Dam Authority (GRDA), is a multiple-arch buttress dam constructed in 1940. The dam has little or no existing geophysical reports on the integrity of the dam foundation rock and even less knowledge at depth. Visual inspection indicated evidence of seepage at some arches of the dam. As a pilot study, we conducted a suite of geophysical surveys inside two arches (Arch-16 and Arch-17) and a part of the downstream berm to characterize the dam foundation rock, delineate seepage zones, and identify the most appropriate geophysical methods for temporal monitoring of the dam’s conditions. The geophysical methods included electrical resistivity tomography (ERT), self-potential (SP), multichannel analysis of surface waves (MASW), compressional (P)-wave refraction, and shear (S)-wave reflection. Water samples were collected for geochemical analysis to investigate the source of the seepage flow inside Arch-16. The geophysical results characterized the dam foundation rock into an unsaturated limestone and chert overlying a water-saturated limestone and chert. The ERT profiles indicated that groundwater is rising inside the arches and significantly dropping under the downstream berm, which can be due to the uplift pressure beneath the dam base. Zones of high seepage potential were detected near the buttress walls of the two surveyed arches, which may be related to previous blasting, excavation of the dam foundation, concrete placement, or improper grouting. The geochemical analysis of water samples taken from the artesian wells inside Arch-16 and the Grand Lake revealed different chemical compositions, suggesting that the source of water could be a mixture of groundwater and lake water or lake water interacting with rock and reaching the surface through fractures; however, more sampling and further analysis are required to ascertain the source of the seeps. This study showed that the ERT, SP, and S-wave reflection methods have effectively characterized the dam foundation rock and seepage zones beneath the arches. The study provided a better understanding of the conditions of the dam foundation rock, evaluated the utilized geophysical methods, and determined the optimum geophysical methods that can be used for the characterization and monitoring of the subsurface conditions along the entire length of the dam. In this study, we have demonstrated that the integration of effective geophysical surveys and geochemical analysis yielded optimum results in solving a complex dam safety problem. This strategy promotes the best practice for dam safety investigation.

A comprehensive study of a 340 m thick lenticular-sheet body of ultramafic composition penetrated by structural well M-1 at a depth of about 2.2 km was accomplished. Its main volume is composed of plagioharzburgite; fine-grained rocks of norite and orthopyroxenite chilling zones are preserved on endocontacts. The rocks of the body are similar in composition to the rocks near the underlying ore-bearing layered intrusion – the Monchepluton. The age of intrusion of the ultramafic body is 2510 ± 9 Ma (U-Pb, ID-TIMS, zircon) and, taking into account analytical errors, is comparable with the formation period of the Monchepluton (2507-2498 Ma). According to the study of the Sm-Nd system in rocks and minerals, a positive value of the eNd (+1.1) parameter was established, similar to that in dunites and chromitites of the Monchepluton. Based on these results, the ultramafic body penetrated at depth was assigned to the magma feeding paleochannel through which the ultramafic, weakly contaminated magma entered the overlying magma chamber. This body is a unique example of a magma-feeding system for the ore-bearing layered intrusion of Precambrian age.

The physical requirements of stone tools tend to prescribe the choice of rocks for their production. Hardness, roughness and impact toughness dictate the ease of knapping as well as the durability of flaked tools, and these rock properties can be measured by mechanical tests described here. Geochemical and petrographic analyses of archaeological and geological samples can also characterise rocks and, under certain circumstances, they enable rock sources to be traced. Examples of how this can be achieved are provided from sites around the world. At Sibudu, KwaZulu-Natal, locally available dolerite and hornfels are the most common rock types employed to make flaked tools. Unfortunately, neither rock lends itself to being sourced, but mechanical tests demonstrate that these rocks have both desirable and undesirable properties for stone-tool manufacture and use. Coarse-grained (rough) dolerite is difficult to knap, but it ensures durable tool edges, whereas fine-grained hornfels is relatively easy to knap, but the sharp edges on its products are sometimes fragile, require resharpening, and have a tendency to break. Dolerite was thus more suited to tool manufacture than we initially realised. [ABSTRACT FROM AUTHOR]