Open AccessEditorial Recent Advances in Geochemistry: Risk Assessment of Soils and Provenance of Geological Materials by Qingjie Gong Qingjie Gong SciProfiles Scilit Preprints.org Google Scholar * and Ningqiang Liu Ningqiang Liu SciProfiles Scilit Preprints.org Google Scholar School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China * Author to whom correspondence should be addressed. Appl. Sci. 2026, 16(12), 5739; https://doi.org/10.3390/app16125739 (registering DOI) Submission received: 31 May 2026 / Accepted: 4 June 2026 / Published: 7 June 2026 This Special Issue, ‘Recent Advances in Geochemistry: Risk Assessment of Soils and Provenance of Geological Materials’, was organized to present papers from the 10th National Conference on Applied Geochemistry in China held in Kunming, Yunnan Province, in November 2024, which aimed to facilitate the academic exchange and presentation of new ideas in the field of applied geochemistry. This Special Issue is edited by the Committee of Applied Geochemistry of the Chinese Society for Mineralogy, Petrology, and Geochemistry (CSMPG). This Special Issue contains nine scientific papers that present various recent advances, challenges, and illustrations in applied geochemistry. These contributions cover broad fields, including environmental geochemistry on pollution risk assessment of soils, provenance of geological materials, exploration and analysis, etc. 2. Pollution Risk Assessment of Soils Heavy metal pollution in soils is an environmental challenge that has attracted global concern [ 1, 2]. Three papers in this Special Issue discuss the pollution risk of metals in soils, crops, and coals. Chen et al. (contribution 1) discuss the risk assessment methods of heavy metals in soils, Li et al. (contribution 2) assess the risk of Selenium in soils and crops, and Junussov and Mustapayeva (contribution 3) discuss the harmful risk of potentially toxic elements in coal ash samples. Methods for assessing heavy metal pollution are generally categorized into three types: pollution indices, released standards, and the integration of these two methods (contribution 1) on single or individual indices. In addition, integrated indices that combine these single indices are also commonly used. 2.1. Methods on Pollution Indices Pollution indices are usually used on heavy metals without released standards. They include the contamination factor (Cf) [ 3, 4], ecological risk factor (Er) [ 3, 5], enrichment factor (EF) [ 6, 7, 8, 9], and index of geo-accumulation (I geo) [ 10, 11]. Here, the index of geo-accumulation is calculated as I geo = log 2[ Ci/(1.5 Cri)] (1) where Ci is the concentration of the element i in a sample and Cri is the background concentration or reference value of the element i such as the values in reference [ 12]. Seven classes of pollution risk are commonly used [ 13, 14, 15] and were primarily suggested by Muller [ 10] on I geo values as I g e o ≤ 0 , c l a s s 0 , u n p o l l u t e d 0 5 , c l a s s 6 , e x t r e m e l y p o l l u t e d (2) 2.2. Methods on Released Standards Based on Equation (3), metals can be evaluated for their released standard values. However, metals cannot be assessed using Equation (3) if they are not specified in these standards. 2.3. Integration Methods on Pollution Indices and Released Standards In order to consistently assess the pollution indices and released standards, Chen et al. (contribution 1) and Huang et al. [ 1] studied the assessment results of both pollution indices and released standards for heavy metals specified in GB15618-2018. They suggest using the integration method to assess heavy metals: P I = 0 C 3.7 , t h e i n t e r v e n t i o n l e v e l (4) where C, CRS, and CRI are those described in Equation (3), and I geo is calculated by Equation (1). Notably, the dividing values of I geo are 1 and 4 in Chen et al. (contribution 1) while the values are 1.4 and 3.7 in Huang et al. [ 1] as listed in Equation (4). This difference resulted from the different values of Cri in Equation (1); therefore, consistent values of Cri in Equation (1) should be derived in China to keep assessment results that are consistent with those of released standard GB15618-2018. 2.4. Integrated Indices That Combine Single Indices Based on the aforementioned single indices such as I geo, PI, Cf, Er, and EF, an integrated index can by formed using their sum, average, weighted average when the single indices are in a normal distribution, or on their product, root of product, and weighted power product when the single indices are in a log-normal distribution [ 23 3. Provenance of Geological Materials 3.1. Provenance on Lithology of Soil–Sediment–Sedimentary Rock LG01 and LG03 lithogenes can be viewed as a tool to classify geological materials compositionally because of their stability during weathering and alteration processes [ 36, 40]. The sample with the acidic-like composition has the same gene code on LG01 and LG03 as 12020202020, while the sample with the basic-like composition has the gene code 10202020202 [ 35]. Acidic similarity (or RAcidic) can be used to classify or trace parent materials to three types: acidic-like composition with RAcidic ≥ 80%, intermediate-like composition with 20% < RAcidic < 80%, and basic-like composition with RAcidic ≤ 20% [ 36, 41]. This classification or provenance is applicable to soil–sediment–sedimentary-rock systems. 3.2. Provenance on Source of Mgamatic Rocks If the rock is sourced from the continental crust, its gene codes, CRG01 and CRG02, are the same as 12020202020. However, if the rock is derived from the lower ocean crust, its CRG01 gene code is 10202020211 and its CRG02 gene code is 10202020202. In geochemical gene research, gene similarity between a sample and continental crust with the code of 12020202020 is called continental crust similarity ( RCrust). RCrust can be viewed as a tool to distinguish the sources of magmatic rocks as three types: CC-like (continental-crust-like) rock with RCrust ≥ 80%, LOC-like (lower-ocean-crust-like) rock with RCrust ≤ 30% on CRG01 or RCrust ≤ 20% on CRG02, and TC-like (transitional-crust-like) rock with 30% < RAcidic < 80% on CRG01 or 20% < RAcidic < 80% on CRG02 [ 37]. This classification or provenance is applicable to magmatic rocks. 4. Exploration and Analysis Zhang et al. (contribution 6) introduce a non-traditional geochemical exploration approach called geo-electrochemical-integrated technology [ 48] in a case study on a uranium deposit in the Guangzitian area of northern Guangxi, China. This geo-electrochemical-integrated technology includes three exploration approaches: geo-electrochemical extraction measurement [ 49], soil ionic conductivity measurement [ 50], and thermally released soil mercury measurement [ 51]. Zhang et al. (contribution 7) report a clean extraction processes to investigate Li concentrations in a clay-type Li deposit; they found that Li is concentrated in fine-grained fractions (<45 μm) in this case deposit, which can be utilized on other clay-type Li deposits [ 52 5. Perspective Although only nine papers in this Special Issue are published, recent advances in geochemistry are clearly illustrated in the fields of environmental geochemistry, geochemical exploration, and geochemical principles on provenance. The innovative studies presented here have great potential, and more advances in geochemistry, especially in applied geochemistry, will emerge in the near future. We thank the authors and reviewers for their contributions to this Special Issue, and anticipate that more in-depth research in applied geochemistry will be showcased at the 11th National Conference on Applied Geochemistry in China. Author Contributions Conceptualization, Q.G. and N.L.; writing—original draft preparation, Q.G. and N.L.; writing—review and editing, Q.G. and N.L. All authors have read and agreed to the published version of the manuscript. Acknowledgments We are grateful to all of the contributors who made this Special Issue a success. Our thanks and congratulations are extended to all the authors for submitting their work. Our sincere gratefulness is also given to the reviewers and editors for the time and effort they spent helping the authors to improve their papers. Conflicts of Interest The authors declare no conflicts of interest. List of Contributions Chen, X.; Zhao, P.; Huang, J.; Liu, J.; Cao, X.; Che, J.; Liao, H.; Zhu, X.; Gong, Q. Risk Assessment of Soil Heavy Metals in the Jiahe River Basin of Yantai City, China. Appl. Sci. 2025, 15, 70. Li, J.; Xie, S.; Yang, W.; Zhou, W.; Carranza, E.J.M.; Wen, W.; Shi, H. Prediction of Selenium-Enriched Crop Zones in Xiaoyan Town Using Fuzzy Logic and Machine Learning Ap-proaches. Appl. Sci. 2025, 15, 4943. Junussov, M.; Mustapayeva, S. Preliminary XRF Analysis of Coal Ash from Jurassic and Car-boniferous Coals at Five Kazakh Mines: Industrial and Environmental Comparisons. Appl. Sci. 2024, 14, 10586. Cui, Z.; Hou, Y. Impacts of Holocene Sea Level Rise and the Opening of the Qiongzhou Strait on the Provenance of Sediments in the Beibu Gulf, South China Sea. Appl. Sci. 2025, 15, 4224. Liu, J.; Liu, C.; Liu, Q.; Luo, Z.; Liu, Y.; Zhou, C.; Guo, X.; Yu, X.; Wang, M. Paleo-Asian Ocean Ridge Subduction: Evidence from Volcanic Rocks in the Fuyun–Qinghe Area, Southern Margin of the Chinese Altay. Appl. Sci. 2025, 15, 3736. Zhang, X.; Wen, M.; Luo, Q.; Ma, Y.; Jiang, Y.; Jiang, Y.; Ye, W.; Zhang, J. Research on the Prediction of Concealed Uranium Deposits Using Geo-Electrochemical Integrated Technology in the Guangzitian Area, Northern Guangxi, China. Appl. Sci. 2025, 15, 7426. Zhang, H.; Li, P.; Zhang, W.; Li, J.; Chen, Z.; Yin, J.; Fang, Y.; Liu, S.; Kang, J.; Zhu, D. Occurrence State and Extraction of Lithium from Jinyinshan Clay-Type Lithium Deposit, Southern Hubei: Novel Blank Roasting–Acid Leaching Processes. Appl. Sci. 2025, 15, 9100. Zhu, L.; Han, R.; Zhang, Y.; Fu, H.; Luo, J.; Luo, Y. Enhancing Prospecting Target Prediction Precision: A Multi-Source Data Mining Approach in Gansu’s Beishan Area. Appl. Sci. 2025, 15, 5430. Feng, B.; Zhang, Z.; Xu, M.; Mao, S. A Thermodynamic Model for the Solubility of SO2 in Multi-Ion Electrolyte Solutions and Its Applications. Appl. Sci. 2025, 15, 3927. References Table 1. Elemental sequences and their reference values for geochemical genes. Table 1. Elemental sequences and their reference values for geochemical genes. Gene Sequence No. 1 2 3 4 5 6 7 8 9 10 11 References Notes: Reference values of major oxides as %; others as μg/g. Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. © 2026 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. Gong, Q.; Liu, N. Recent Advances in Geochemistry: Risk Assessment of Soils and Provenance of Geological Materials. Appl. Sci. 2026, 16, 5739. https://doi.org/10.3390/app16125739 Gong Q, Liu N. Recent Advances in Geochemistry: Risk Assessment of Soils and Provenance of Geological Materials. Applied Sciences. 2026; 16(12):5739. https://doi.org/10.3390/app16125739 Gong, Qingjie, and Ningqiang Liu. 2026. "Recent Advances in Geochemistry: Risk Assessment of Soils and Provenance of Geological Materials" Applied Sciences 16, no. 12: 5739. https://doi.org/10.3390/app16125739 Gong, Q., & Liu, N. (2026). Recent Advances in Geochemistry: Risk Assessment of Soils and Provenance of Geological Materials. Applied Sciences, 16(12), 5739. https://doi.org/10.3390/app16125739 Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.
Recent Advances in Geochemistry: Risk Assessment of Soils and Provenance of Geological Materials
