Journal of Geochemical Exploration最新文献

{"title":"Provenance analysis signposts for sedimentary uranium exploration in aeolian sandstone systems: Insights from the Luohe Formation, Western Ordos Basin","authors":"Rui Tao ,&nbsp;Yang Song ,&nbsp;Liang Duan ,&nbsp;Mingtao Li","doi":"10.1016/j.gexplo.2025.107672","DOIUrl":"10.1016/j.gexplo.2025.107672","url":null,"abstract":"<div><div>The Lower Cretaceous Luohe Formation in the western Ordos Basin, North China, represents a rare aeolian sedimentary system with distinctive “uranium-bearing” characteristics. Sedimentary source of the uranium-bearing sandstones in this formation, which is crucial for advancing uranium exploration efforts, remains ambiguous. This study undertakes a comprehensive investigation encompassing petrology, geochemistry, and detrital zircon systematics (including zircon U–Pb ages, trace elements, and Hf isotopes) on the aeolian sandstones of the Luohe Formation within the western Ordos Basin. The objective is to provide crucial insights into conventional exploration for sedimentary uranium resources within aeolian sedimentary systems in intracontinental basins. Detrital zircon ages are categorized into a predominant age grouping within the Phanerozoic era (210–450 Ma), with notable peaks observed at 260 Ma and 420 Ma. Additionally, two minor age clusters are identified in the Early Paleoproterozoic (2240–2600 Ma), notably peaking at 2460 Ma, and the Late Paleoproterozoic (1600–2150 Ma), with a peak observed at 1850 Ma. Integrating the geochemical discrimination diagrams, it is suggested that the Alxa Block to the west of the Ordos Basin serves as the main provenance supplier of the hard detrital zircons. The uranium-bearing debris from the Alxa Block underwent sedimentary recycling and, therefore, were transported to the paleouplifts that formed on the western Ordos Basin during the Late Jurassic to Early Cretaceous. The paleoclimatic conditions characterized by prolonged arid periods interspersed with brief humid and warm episodes are crucial for the unique “uranium-bearing” nature of the sandstones. The sedimentary environment, dominated by aeolian deposition with localized fluvial deposition at basin-mountain interfaces, is identified as an ideal setting for uranium storage within aeolian sedimentary systems. We finally propose a generalized approach for exploring uranium reservoirs in aeolian sandstone systems at the basin level.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"271 ","pages":"Article 107672"},"PeriodicalIF":3.4,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics, water quality, health risks and sources of heavy metals of Qu River Basin","authors":"Dong Fu ,&nbsp;Yanchuan Gong ,&nbsp;Hua Liu ,&nbsp;Lvshan Zhou ,&nbsp;Wenjun Xiang ,&nbsp;Chenzheng Du","doi":"10.1016/j.gexplo.2025.107676","DOIUrl":"10.1016/j.gexplo.2025.107676","url":null,"abstract":"<div><div>With the continuous accumulation of heavy metals (HMs), the threat of HMs to the ecological environment has attracted high attention worldwide. The Qu River basin is located in the upper reaches of the Yangtze River, the largest river in China, but its water quality spatio-temporal distribution characteristics, pollution sources and health risks of HMs are still kept unclear. In this work, based on 2160 samples containing 8 HMs including Hg, Pb, Se, As, Cu, Cd, Zn and Cr from 36 sampling sites, the health risks, water quality variation characteristics and pollution sources in the Qu River Basin were studied. The mean HMs concentration varied in different seasons, with higher content of Zn, Cd, Cu, Pb and Cr in dry season, higher As value in wet season. The water quality distribution pattern of Qu River Basin shows that the upstream is superior to that in the middle and downstream. Health risks of Cd and Cr were most pronounced during the study period. Moreover, Cd poses a greater potential health risk in dry season while Cr in the rainy season, respectively. Positive matrix factorization (PMF) receptor model indicated that industrial pollution (26.2 %), soil erosion (24.3 %), natural source (22.4 %), atmospheric deposition (21.0 %) and agricultural activities (6.1 %) are identified as the potentially sources of HMs of the surface waters in Qu River Basin. Therefore, from the perspective of health risks, the treatment and discharge monitoring of industrial wastewater and the restoration of soil contaminated by HMs should be further strengthened in the Qu River basin. This work will provide basic data for water quality improvement and resource utilization of Qu River Basin.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"271 ","pages":"Article 107676"},"PeriodicalIF":3.4,"publicationDate":"2025-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A geospatial analysis of coal mine overburden reclamation: Land use, carbon stock, biomass, and soil genesis in chronosequence plantations","authors":"Tarun Kumar Thakur ,&nbsp;Digvesh Kumar Patel ,&nbsp;Sandhya Saini ,&nbsp;Anita Thakur ,&nbsp;Singam Laxmana Swamy ,&nbsp;Sanjeev Bakshi ,&nbsp;Amit Kumar ,&nbsp;Fohad Mabood Husain ,&nbsp;Rupesh Kumar","doi":"10.1016/j.gexplo.2025.107674","DOIUrl":"10.1016/j.gexplo.2025.107674","url":null,"abstract":"<div><div>Coal remains a pivotal energy source, meeting 27 % of global energy demand and 70 % of India's energy requirements. However, coal mining significantly disrupts land use, necessitating effective reclamation strategies. This study examines the repercussions of coal mining on land use disruption and assesses the benefits of revegetation on structural attributes, biomass, carbon sequestration, and soil restoration in central India. Utilizing Landsat 9 satellite imagery, we characterized land use and vegetation dynamics, employing the Normalized Difference Vegetation Index (NDVI) to classify five distinct age sequence classes with median ages of 5, 10, 20, 30, and 40 years. Results indicated a decrease in tree density from 1408 to 588 trees per hectare as plantations aged from 5 to 40 years, while the basal area increased from 5.88 to 28.25 m² per hectare. Notably, values in 40-year-old stands approached those of natural forests. Key novelties include the identification of a strong correlation between spectral vegetation indices (SVIs) and soil quality indicators, providing a remote-sensing-based framework for monitoring ecological restoration. Both total standing biomass and carbon stock exhibited significant (<em>p</em> ≤ 0.05) increases with plantation age, ranging from 10.25 to 66.41 Mg ha⁻¹ and 5.16 to 32.74 Mg ha⁻¹, respectively. Soil carbon content decreased with depth, with values ranging from 7.68 to 18.98 Mg ha⁻¹ at 0–20 cm depth, and soil nitrogen values spanning 82.66 to 216.08 kg ha⁻¹. These findings underscore the necessity of site-specific management strategies that integrate technological, ecological, and economic considerations to advance ecological restoration and align with the Sustainable Development Goals by 2030.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"271 ","pages":"Article 107674"},"PeriodicalIF":3.4,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution dynamics and health risks of polyaromatic hydrocarbons and heavy metals in the anthropogenically impacted Omi-Asoro Stream, Nigeria","authors":"Adebanjo Jacob Anifowose ,&nbsp;Gideon Temitope Arowosaye ,&nbsp;Oluwaseyi Esther Adaramodu ,&nbsp;Esther Oluwaponmile Akintola ,&nbsp;Jesufunmilayo Abosede Otunniya ,&nbsp;Adedoyin Demilade Makinde ,&nbsp;Tesleem Olalekan Kolawole ,&nbsp;Shola Hezekiah Awojide","doi":"10.1016/j.gexplo.2025.107675","DOIUrl":"10.1016/j.gexplo.2025.107675","url":null,"abstract":"<div><div>The study carried out concerted analytical measurements of twenty polyaromatic hydrocarbons (PAHs) and eighteen heavy metals in the Omi-Asoro Stream, Ilesa, Nigeria to unravel their sources and the impacts of anthropogenic activities around it. Samples from the stream water were collected in March 2023. The resident PAHs were subjected to solid-phase extraction (SPE) and analyzed on a gas chromatograph-mass spectrometer. The acid-extracted heavy metals were also analyzed with an inductively coupled plasma-optical emission spectrometer (ICP-OES). Results showed that naphthalene (6.00 ± 7.79 μg/L) and fluoranthene (2.99 ± 4.24 μg/L) were the two dominant PAHs in the stream water. Similarly, Fe and Zn, with concentrations (μg/L) of 1291 ± 2361 and 53.1 ± 89.3, respectively, were the dominant heavy metals. Fe concentration constituted 84.4% of the total heavy metals in the water. Using principal component analysis (PCA), the PAH sources were traced to internal combustion engines, biomass burning, and pesticides/wood preservatives. The heavy metal sources were resolved to internal combustion of engines, metallic wear/rust, electronic devices, geogenic releases and agrochemicals. The risk assessment showed that among the detected PAHs, benzo(<em>a</em>)pyrene constituted a carcinogenic effect on humans. The heavy metals which posed carcinogenic effects included As, Ni, Cd and Cr. Thus, the industrial and agricultural activities, as well as emissions from the internal combustion of engines in the area released the environmental pollutants which adversely impacted the stream.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"271 ","pages":"Article 107675"},"PeriodicalIF":3.4,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unsupervised detection of multivariate geochemical anomalies using a high-performance deep autoencoder Gaussian mixture model","authors":"Xuemei Wang,&nbsp;Yongliang Chen","doi":"10.1016/j.gexplo.2025.107671","DOIUrl":"10.1016/j.gexplo.2025.107671","url":null,"abstract":"<div><div>It is of great significance to construct an efficient geochemical anomaly detection model for the successful accomplishment of a mineral exploration process in a complex geological environment. However, the complex geological environment of the prospecting area often results in the high-dimensional unknown complex population distribution of geochemical exploration data. This complex distribution is difficult to fit with a theoretical probability distribution model. As a result, it becomes a challenge to carry out an effective detection of geochemical anomalies. Therefore, to develop an anomaly detection model that can effectively fit the complex population distribution of geochemical exploration data is the key for accurately detecting geochemical anomalies. For this reason, the deep autoencoder Gaussian mixture model (DAGMM) was adopted to model the geochemical exploration data obtained in the 1:200,000 geological survey conducted in the Baishan area (Jilin, China) to check its superiority in identifying multivariate geochemical anomalies. As an innovative deep learning framework for unsupervised anomaly detection, DAGMM ingeniously combines the data dimensionality reduction and compression capabilities of a deep autoencoder (DAE) with the probability density estimation advantage of the Gaussian mixture model (GMM). The DAGMM model can deeply explore the deep-level features of geochemical exploration data and effectively model the complex unknown data distribution through the synergistically work and joint optimization strategy in training the DAE and GMM model, so it can accurately identify geochemical anomalies. To show the superiority of the DAGMM model in detecting polymetallic geochemical anomalies, the DAGMM model was compared with the GMM and DAE models. The receiver operating characteristic (ROC) curves of the three models were plotted, and the areas under the ROC curves (AUCs) and lift indices were calculated. The ROC curve of the DAGMM model dominates that of the DAE model and GMM model. The DAGMM model has an AUC of 0.904 and a lift index of 10.44, respectively, which are much larger than those of the GMM model (AUC = 0.858, lift index = 3.63) and DAE model (AUC = 0.83, lift index = 5.31). Therefore, the DAGMM model significantly outperforms the other two models in detecting multivariate geochemical anomalies and the polymetallic geochemical anomalies detected by the DAGMM model contain all the known polymetallic deposits. Compared with DAE and GMM, DAGMM is more efficient and more powerful in detecting multivariate geochemical anomalies in complex geological environments.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"271 ","pages":"Article 107671"},"PeriodicalIF":3.4,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling mineralization potential of catchment basins: Insight from geochemical fingerprint","authors":"Haicheng Wang ,&nbsp;Ruiwen Shen ,&nbsp;Liuan Duan ,&nbsp;Qiuming Cheng ,&nbsp;Zhaoxian Yuan ,&nbsp;Shengyuan Zhang","doi":"10.1016/j.gexplo.2025.107669","DOIUrl":"10.1016/j.gexplo.2025.107669","url":null,"abstract":"<div><div>Stream sediments are common sampling media in cost-effective regional exploration programs. Catchment basins are the basic sampling units of steam sediments, which have distinct geochemical characteristics. In this study, the mineralization potential of catchment basin using stream sediments is evaluated from the perspective of geochemical fingerprints. Firstly, the spatial distribution of catchment basins was acquired based on digital elevation model data. The local singularity analysis was employed to reduce the impact of the overburden, revealing the weak geochemical anomalies. The catchment basins with known mineral occurrences as the prior dataset were used to train the random forest model, which improved the model accuracy and interpretability. The geochemical fingerprints of different types of mineralization were constructed based on the importance of geochemical variables in the random forest modeling, which revealed the importance of geochemical elements for different types of mineralization occurrences. All catchment basins lacking mineral occurrences were categorized based on the trained random forest model, achieving the potential types of mineralization for each catchment basin. Most of catchment basins with the same types of mineralization occurrences exhibited the spatial cluster, suggesting the migration characteristics of metal element in stream sediments through river system. Geochemical fingerprinting is a valuable tool for classifying the different types of mineralization occurrences at the scale of catchment basins. The delineated potential mineral occurrence types for catchment basins provided an indicator for future mineral exploration endeavors.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"271 ","pages":"Article 107669"},"PeriodicalIF":3.4,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uptake and toxicity of heavy metals: The protective frontiers of metal binding proteins","authors":"Ravneet Kaur,&nbsp;Harleen Kaur,&nbsp;Ashish Sharma","doi":"10.1016/j.gexplo.2025.107673","DOIUrl":"10.1016/j.gexplo.2025.107673","url":null,"abstract":"<div><div>In environment, several contaminants and pollutants are released, the content of which is increasing alarmingly. Out of several contaminants released into environment, one such contaminant is heavy metals. Such contaminants being released into the environment then enter into plant system via soil. Plants uptake heavy metals from soil via apoplast symplast continuum. Plant require several nutrients in minute concentrations however presence of such nutrients in excess cause toxic effects on plants. Such heavy metals caused varied toxicities such as chlorosis, impaired photosynthesis, lipid peroxidation etc. in plants resulting in overall decline in plant biomass. Excess concentration of heavy metals such as copper, chromium, nickel are known to induce morphological, physiological deformities in several plant species. In response to ROS generated due to heavy metal toxicity, plants activate several defense mechanisms. In addition to this, several metal binding proteins such as metallothioneins, phytochelatins, glutathione etc. are activated. These metal binding protein act to reduce the toxic effects of heavy metals by binfing to them and sequestering then into vacuoles. The current review will highlight the uptake mechanism of heavy metals by plants, toxicity caused by some commonly occurring heavy metals in plants and role of metal binding proteins in sequestering such heavy metals.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"271 ","pages":"Article 107673"},"PeriodicalIF":3.4,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using principal component analysis to distinguish sources of radioactivity and nitrates contamination in Southern Tunisian groundwater samples","authors":"Tiziano Boschetti ,&nbsp;Younes Hamed ,&nbsp;Rihab Hadji ,&nbsp;Maurizio Barbieri ,&nbsp;Matteo Gentilucci ,&nbsp;Mattia Rossi ,&nbsp;Rayan Khalil ,&nbsp;Shuhab D. Khan ,&nbsp;Bassem Asghar ,&nbsp;Abdulrasoul Al-Omran ,&nbsp;Elimame Elaloui","doi":"10.1016/j.gexplo.2025.107670","DOIUrl":"10.1016/j.gexplo.2025.107670","url":null,"abstract":"<div><div>The manuscript discusses using Principal Component Analysis (PCA) to distinguish the sources of radioactive and nitrate contamination in 33 groundwater samples from southern Tunisia. The study focuses on the Gafsa basin, an area known for its phosphate mining activities and significant agricultural use, both of which contribute to the contamination of groundwater resources. The radioactivity in the water is primarily attributed to phosphate mining and deep groundwater sources from the North Western Sahara Aquifer System (NWSAS). Additionally, the nitrate contamination is largely due to agricultural runoff, though secondary sources related to phosphate mining are also considered.</div><div>Through the application of PCA, the study was able to classify the groundwater samples into different groups based on their contamination sources: phosphate mining, combined agricultural and mining activities, fossil geothermal waters, and low-agricultural areas. The PCA revealed that samples most affected by anthropogenic activities exhibited high levels of radium and nitrate, with contamination patterns correlating with specific environmental and chemical factors.</div><div>This analysis underscores the complexity of groundwater contamination in the region and highlights the need for targeted mitigation strategies to address radioactive and nitrate pollution in southern Tunisia. The study provides critical insights for managing water quality in areas with similar environmental challenges.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"271 ","pages":"Article 107670"},"PeriodicalIF":3.4,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Assessment of potentially toxic elements in some wild edible plants of district Doda, Jammu and Kashmir, India” [J. Geochem. Explor. 267, p. 107604. (Dec 2024)]","authors":"Sania Hamid ,&nbsp;Devendra Kumar Pandey ,&nbsp;Deepika Singh","doi":"10.1016/j.gexplo.2024.107668","DOIUrl":"10.1016/j.gexplo.2024.107668","url":null,"abstract":"","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"270 ","pages":"Article 107668"},"PeriodicalIF":3.4,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vectoring towards buried high-purity quartz metapegmatites using low-elevation radiometric and soil geochemical surveying: Method validation in Tysfjord, Norway","authors":"Mario Hopfner ,&nbsp;Marco Brönner ,&nbsp;Lawrence Carter ,&nbsp;Teimoor Nazari-Dehkordi ,&nbsp;Julian Menuge ,&nbsp;Axel Müller ,&nbsp;Ben Williamson","doi":"10.1016/j.gexplo.2024.107667","DOIUrl":"10.1016/j.gexplo.2024.107667","url":null,"abstract":"<div><div>Group 2/NYF pegmatites may be economically enriched in rare minerals. In this study we report testing of two exploration methods, gamma ray surveying and soil geochemical mapping, undertaken within the GREENPEG project. Palaeoproterozoic metapegmatites in the Tysfjord area, Nordland, Norway, include some which have been mined for pure quartz. Geologically, the ore zones are the quartz cores of metapegmatites whose other zones and metasomatic halos are enriched in U, Th, REE, Nb and other rare elements. The Jennyhaugen metapegmatite was the main test site because its subcrop beneath 0.1–1.0 m soil can be traced from an open pit mine, and aerial surveying is unobstructed by trees. Helicopter-borne radiometry at 60 m altitude and drone-borne radiometry at 25–35 m altitude detect the metapegmatite, while walking (1.0 or 1.6 m height) and 15 m altitude drone-borne radiometry resolve the metapegmatite and metasomatic halo subcrop in detail. Total gamma ray count measurements provide as good an exploration tool as Th or U radiation; K radiation does not show useful anomalies. Both A- and C-horizon soil geochemical mapping also reveal U, Th, Nb and other geochemical anomalies above metapegmatite and halo subcrop. A-horizon soil samples appear to more accurately locate these targets, perhaps because they effectively sample larger surface areas of subcropping rock, whose grain size is very coarse (typically metre scale) within the metapegmatite. C-horizon samples collected from the soil-rock interface are less likely to be representative of the metapegmatite. Gamma ray surveying is recommended rather than soil chemical mapping for exploration, by helicopter at district scale and by drone or walking at prospect scale. It is quicker, requires less field workers, has higher resolution and is less expensive than soil geochemical mapping. Soil chemistry may be preferred for prospect-scale exploration, however, where the commodity sought does not spatially correlate with U and/or Th concentrations.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"270 ","pages":"Article 107667"},"PeriodicalIF":3.4,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}