Applied Geochemistry最新文献_第7页

Geochemical characterization and potential impact of coal mine drainage on river water quality at selected coal mines in the Livingstonia Coalfield, Malawi 马拉维Livingstonia煤田选定煤矿的地球化学特征及其对河流水质的潜在影响

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-20 DOI: 10.1016/j.apgeochem.2025.106636

Amidu A. Makwinja , Frances Chikanda , George J. Maneya , Ryosuke Kikuchi , Walubita Mufalo , Akizumi Ishida , Tsubasa Otake

Coal mining can have significant environmental impacts caused by acid mine drainage (AMD). To further our understanding of the environmental impacts of coal mining, a study was conducted in the Livingstonia Coalfield at the Kaziwiziwi and Mchenga coal mines in Malawi. Mine drainage, river water, and rock samples were analyzed to determine their geochemical characteristics and assess potential environmental impacts. Results of onsite measurements and chemical analyses showed that mine drainage at both sites is moderately acidic to neutral (pH = 4.46–7.02) with Fe²⁺ and SO₄²⁻ concentrations of 0.30–3.75 and 92.7–593 ppm, respectively. The presence of Fe and SO₄ ions is indicative of FeS₂ oxidation, which is responsible for AMD. At Kaziwiziwi, AMD was identified at the tailings pond, whereas at Mchenga it occurs in an abandoned underground mine. The underground drainage from the Kaziwiziwi active mine has high concentrations of Ca²⁺, Mg²⁺, and HCO₃⁻, indicating the natural neutralization of AMD by mixing with alkaline groundwater. River water has a circumneutral pH and low trace element concentrations (<1 ppm), suggesting minimal AMD. However, the rock samples, particularly mudstone, have acid-generating potential and are a long-term AMD risk. Stable S isotopic analysis indicates that sulfate ions in the AMD are derived from the mudstone, suggesting this rock type is a major source of AMD. Geochemical mixing modeling predicts that fluctuations in river water pH and increased concentrations of dissolved metals (e.g., Mn) will occur when mixed with AMD, thereby highlighting the need for monitoring and mitigation strategies.

煤矿开采中酸性矿井水对环境的影响很大。为了进一步了解煤炭开采对环境的影响，我们在马拉维的Kaziwiziwi和Mchenga煤矿的Livingstonia煤田进行了一项研究。对矿井水、河水和岩石样品进行了分析，确定了它们的地球化学特征，并评估了潜在的环境影响。现场测量和化学分析结果表明，两个矿区的矿井水均为中酸性至中性（pH = 4.46 ~ 7.02）， Fe2+和SO42−浓度分别为0.30 ~ 3.75 ppm和92.7 ~ 593 ppm。Fe和SO4离子的存在表明FeS2氧化，这是AMD的原因。在Kaziwiziwi， AMD是在尾矿库发现的，而在Mchenga，它发生在一个废弃的地下矿山。Kaziwiziwi活矿地下排水中Ca2+、Mg2+和HCO3−浓度较高，表明AMD与碱性地下水混合自然中和。河水的pH值为环中性，微量元素浓度很低（1 ppm），表明AMD很轻微。然而，岩石样本，特别是泥岩，具有产酸潜力，长期存在AMD风险。稳定S同位素分析表明，AMD中的硫酸盐离子来源于泥岩，表明该岩型是AMD的主要来源。地球化学混合模型预测，当与AMD混合时，河水pH值会出现波动，溶解金属（如锰）的浓度会增加，因此强调需要监测和缓解战略。

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引用次数: 0

A geochemical gene of pollution risk (PRG01) for assessing heavy metal pollution based on the relative relationship between elements 基于元素间相对关系的重金属污染风险地球化学基因(PRG01

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-19 DOI: 10.1016/j.apgeochem.2025.106634

Jiaxin Huang , Shengchao Xu , Ningqiang Liu , Taotao Yan , Qingjie Gong

Traditional assessments of heavy metal pollution in soils are often carried out on pollution indices and national standards. However, these methods focus on only elemental concentrations, without considering the relative relationship among elements. Here, we propose a geochemical gene of pollution risk (PRG01) and its risk similarity (R_Risk), which are based on the relative relationship between concentrations of heavy metals (Hg, Pb, Cd, Cr, and As) and their contrast elements (Ti, La, Zr, Th, U, and Nb). Through risk similarity, the pollution risk of heavy metals of samples can be classified into six levels, including the safety level (R_Risk<20 %) and the risk level 1 to 5 (corresponding R_Risk values range from 20 % to 100 %). The geochemical gene of PRG01 and its risk similarity were applied in the Dashanbao area of Yunnan province of China and compared with the national standard GB15618-2018 on the pollution risk assessment of heavy metals in agricultural soils. The results indicate that samples with R_Risk<20 % (or in safety level) belong to the non-intervention level (background or screening levels), while samples with R_Risk≥40 % are at the non-background level (screening or intervention levels). Therefore, the PRG01 technique can be used as a novel approach and its risk similarity can be viewed as an integrated index for assessing the pollution risk of heavy metals (i.e., Hg, Pb, Cd, Cr, and As) in agricultural soils. The assessment index of risk similarity of PRG01 can not only circumvent the limitation of a one-size-fits-all approach but also compensate for the limitation of GB15618-2018 in assessing soil samples when agricultural land use type and pH data are missing.

传统的土壤重金属污染评价通常是根据污染指数和国家标准进行的。然而，这些方法只关注元素浓度，而没有考虑元素之间的相对关系。本文基于重金属（Hg、Pb、Cd、Cr和As）及其对比元素（Ti、La、Zr、Th、U和Nb）浓度的相对关系，提出了污染风险地球化学基因（PRG01）及其风险相似性基因（RRisk）。通过风险相似性，将样品重金属污染风险分为6个等级，包括安全等级（RRisk< 20%）和风险等级1 ~ 5（对应的RRisk值为20% ~ 100%）。将PRG01地球化学基因及其风险相似性应用于云南大山堡地区，并与《农业土壤重金属污染风险评价》国家标准GB15618-2018进行比较。结果表明，RRisk< 20%（或安全水平）的样本属于非干预水平（背景或筛查水平），而RRisk≥40%的样本属于非背景水平（筛查或干预水平）。因此，PRG01技术可作为一种新方法，其风险相似度可作为评价农业土壤中重金属（Hg、Pb、Cd、Cr、as）污染风险的综合指标。PRG01风险相似度评价指标不仅可以规避“一刀切”方法的局限性，还可以弥补GB15618-2018在缺少农用地类型和pH值数据时对土壤样品评价的局限性。

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引用次数: 0

Unraveling stress-mediated fluid-fault interactions in 2021–2022 seismic sequence: Insights from unsupervised machine learning and multiparametric hydrochemical anomalies in Xianshuihe fault zone 2021-2022年地震序列中应力-断层相互作用的揭示：来自鲜水河断裂带无监督机器学习和多参数水化学异常的见解

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-19 DOI: 10.1016/j.apgeochem.2025.106635

Yucong Yan , Zheming Shi , Xiaocheng Zhou , Guangcai Wang , Zuochen Zhang , Yunfei Bai , Zhaojun Zeng , Bingyu Yao , Yuwen Wang , Miao He , Jiao Tian , Ruibin Li , Han Yan

Earthquake-related hydrochemical changes in thermal springs have been widely observed, yet the temporal dynamics and controlling mechanisms of pre- and post-seismic hydrochemical changes remains poorly constrained. By employing unsupervised machine learning (SOM-KM), this study investigates earthquake-induced changes of major elements, trace elements, and hydrogen-oxygen isotopes by high-frequency monitoring data in two thermal springs (XXX and LTG) along the Xianshuihe fault zone during the 2021–2022 Ms ≥ 6.0 earthquake sequence. The result shows that: the XXX spring (Moxi segment) exhibited consistent co-seismic dilution of major ions (Na⁺, K⁺, Cl⁻, HCO₃⁻) and trace elements, attributed to shallow fracture opening under low normal stress (200–400 MPa), thereby facilitating meteoric water recharge (81–89 % mixing ratio). Conversely, the LTG spring (Kangding segment) showed enrichment of deep-sourced constituents of pre-seismic major elements (Na⁺, K⁺, Cl⁻, HCO₃⁻) surges during the 2021 Luxian Ms6.0 earthquake, and post-seismic trace element fluctuation in 2022 Ms ≥ 6.0 earthquake sequence, driven by high stress (400–600 MPa) enhancing deep fracture dilation, fluid ascent, and water-rock interaction (obvious δ¹⁸O drift). Cross-analysis of hydrogeochemical signatures with geological and geophysical evidence demonstrates that earthquake-induced hyrochemical anomalies are governed by (1) regional tectonics stress; (2) fault-segment heterogeneity; (3) fluid pathway reorganization and water-rock interaction dynamics. This work advances the understanding of fault-zone fluid response mechanisms to seismicity and offers novel insights into crustal fluid-tectonic interactions during earthquake cycles.

地震相关的温泉水化学变化已被广泛观察到，但对地震前后水化学变化的时间动力学和控制机制却知之甚少。采用无监督机器学习（SOM-KM）方法，利用仙水河断裂带XXX和LTG两个温泉在2021-2022年Ms≥6.0级地震序列期间的高频监测数据，研究了主元素、微量元素和氢氧同位素的地震诱发变化。结果表明：XXX泉（磨溪段）主要离子（Na+、K+、Cl−、HCO3−）和微量元素的同震稀释一致，这是由于在低正应力（200 ~ 400 MPa）条件下浅裂缝张开，有利于大气水补给（混合比81 ~ 89%）。相反，LTG泉（康定段）在高应力（400 ~ 600 MPa）的驱动下，在2021年陆县Ms6.0级地震期间表现出震前主元素（Na+、K+、Cl−、HCO3−）深源成分的富集，在2022年Ms≥6.0级地震序列中表现出震后微量元素的波动，增强了深部裂缝扩张、流体上升和水岩相互作用（明显的δ18O漂移）。水文地球化学特征与地质和地球物理证据的交叉分析表明，地震引起的水化学异常受(1)区域构造应力的控制；(2)断层段异质性；(3)流体通道重组与水岩相互作用动力学。这项工作促进了对断裂带流体对地震活动性的响应机制的理解，并为地震周期中地壳流体-构造相互作用提供了新的见解。

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引用次数: 0

Impact of salinity gradient on sediment microbial communities and the functions of carbon, nitrogen, and sulfur cycling in coastal zone 盐度梯度对海岸带沉积物微生物群落及碳、氮、硫循环功能的影响

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-17 DOI: 10.1016/j.apgeochem.2025.106609

Dahai Wang , Chuanshun Zhi , Xiaonong Hu , Zhen Wu , Wei Song , Jian Wang , Xianrui Huang , Fan Yang , Yufei Jiao , Yuxi Li

Coastal sediments, located at the terrestrial–marine interfaces and subject to strong salinity gradients, harbor distinct microbial communities that play indispensable roles in sustaining carbon, nitrogen, and sulfur cycling, yet the responses to salinization remain insufficiently understood. This study aims to characterize microbial community structures within coastal sediments by employing high-throughput sequencing of the 16S rRNA gene. Furthermore, we utilized the FAPROTAX and PICRUSt2 prediction tools to elucidate microbial functions and biogeochemical cycling processes in these sediment ecosystems. The results revealed that increasing salinity significantly increased microbial α-diversity and promoted the expansion of salt-tolerant microbial populations. The salinity-driven increase in microbial network complexity was accompanied by more pronounced competitive interactions. Salinity variations also significantly altered the microbial functions associated with carbon, nitrogen, and sulfur cycling in the sediments. In low-salinity environments, the ability to decompose complex carbon sources was higher, while in high-salinity environments, microbial communities relied more on chitin degradation, starch degradation, and reductive acetogenesis to cope with the high-salinity, low-oxygen conditions. In the nitrogen cycle, mild salinization promoted denitrification, but in the later stages of salinization, high salinity suppressed denitrification, while nitrogen fixation was enhanced in high-salinity environments. The sulfur cycle, both sulfur oxidation and reduction processes were active in medium-salinity sediments, whereas sulfur oxidation was more pronounced and sulfur reduction was diminished in high-salinity sediments, particularly sulfide oxidation and thiosulfate oxidation were enhanced, while dissimilatory sulfate reduction was weakened. This study reveals the effects of salinity gradients on sediment microbial communities and their functions, providing theoretical support for future ecological restoration and environmental management.

沿海沉积物位于海陆界面，受强盐度梯度影响，拥有独特的微生物群落，这些微生物群落在维持碳、氮和硫循环中起着不可或缺的作用，但对盐碱化的响应仍未充分了解。本研究旨在通过16S rRNA基因的高通量测序来表征沿海沉积物中的微生物群落结构。此外，我们利用FAPROTAX和PICRUSt2预测工具阐明了这些沉积物生态系统的微生物功能和生物地球化学循环过程。结果表明，盐度的增加显著增加了微生物α-多样性，促进了耐盐微生物种群的扩大。盐度驱动的微生物网络复杂性的增加伴随着更明显的竞争相互作用。盐度变化也显著改变了沉积物中与碳、氮和硫循环相关的微生物功能。在低盐度环境中，微生物群落对复杂碳源的分解能力更高，而在高盐度环境中，微生物群落更多地依靠几丁质降解、淀粉降解和还原性产氢来应对高盐度、低氧条件。在氮循环中，轻度盐渍化促进了反硝化作用，但在盐渍化后期，高盐度抑制了反硝化作用，而在高盐度环境中，固氮作用增强。中盐度沉积物的硫循环、硫氧化和硫还原过程都很活跃，而高盐度沉积物的硫氧化作用更为明显，硫还原作用减弱，特别是硫化物氧化和硫代硫酸盐氧化作用增强，而异化硫酸盐还原作用减弱。该研究揭示了盐度梯度对沉积物微生物群落及其功能的影响，为未来的生态恢复和环境管理提供理论支持。

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引用次数: 0

Strontium isotopes and Rb/Sr tracers in surface soils for locating subsurface lithium pegmatites 表层土壤中的锶同位素和Rb/Sr示踪剂用于定位地下锂伟晶岩

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-14 DOI: 10.1016/j.apgeochem.2025.106631

Grace A. Hall , Gordon D.Z. Williams , Mona-Liza C. Sirbescu , P. Louis Lu , Gary S. Dwyer , Daniel D. Richter , Avner Vengosh

Lithium-cesium-tantalum (LCT) pegmatites are a major source of global Li production. They typically occur as dike swarms intruded into metamorphic country rocks. The subsurface locations of these dikes can be difficult to identify from the surface. One common approach is to investigate geochemical anomalies in overlying soils and use these as indicators for the occurrence of subsurface pegmatite dikes. However, even with these methods, economically valuable pegmatites can be difficult to identify, and additional techniques can be beneficial for optimizing geological exploration. Here we present a new methodology for detecting subsurface pegmatites through the analysis of Rb/Sr and strontium isotope (⁸⁷Sr/⁸⁶Sr) variations in relatively shallow soils overlying LCT pegmatites. During their formation, pegmatites become enriched in Rb and depleted in Sr, resulting in distinctly high Rb/Sr ratios (typically ≫10), and with time, the decay of ⁸⁷Rb leads to high ⁸⁷Sr/⁸⁶Sr ratios (typically ≫1.0) far exceeding those of common regional host rocks (typically with Rb/Sr < 10 and ⁸⁷Sr/⁸⁶Sr < ∼0.75). Since soils primarily inherit the ⁸⁷Sr/⁸⁶Sr values of their underlying parent rocks, we propose using these distinctive geochemical fingerprints in site-specific soil geochemical surveys to detect subsurface LCT pegmatites. We demonstrate the potential and utility of this methodology using surface soils around and overlying buried LCT pegmatites in the Late Paleozoic Tin Spodumene Belt in North Carolina and the Proterozoic Animikie Red Ace in Wisconsin, USA. Soils directly overlying the LCT pegmatites inherit distinctly elevated Rb/Sr (∼10–120) and ⁸⁷Sr/⁸⁶Sr (∼1.0–6.8) ratios compared to background soils away from the buried LCT pegmatites (⁸⁷Sr/⁸⁶Sr ∼0.74–0.77, Rb/Sr ∼0.76–3.9), which can be used to identify and reconstruct the location of subsurface LCT pegmatite dikes. The common and uniquely elevated Rb/Sr and ⁸⁷Sr/⁸⁶Sr signatures of global pegmatites suggest that this method can be widely and globally applied to soils derived from LCT pegmatites.

锂-铯-钽（LCT）伟晶岩是全球锂生产的主要来源。它们通常以侵入变质岩的岩脉群的形式出现。这些岩脉的地下位置很难从地表识别出来。一种常见的方法是研究上覆土壤中的地球化学异常，并将这些异常作为地下伟晶岩岩脉存在的指标。然而，即使使用这些方法，具有经济价值的伟晶岩也难以识别，而其他技术可能有助于优化地质勘探。本文提出了一种通过分析LCT伟晶岩上覆较浅土壤Rb/Sr和锶同位素（87Sr/86Sr）变化来探测地下伟晶岩的新方法。伟晶岩在形成过程中富Rb、贫Sr，形成明显的高Rb/Sr比值（一般为> 10），随着时间的推移，87Rb的衰变导致高87Sr/86Sr比值（一般为> 1.0），远远超过区域普通寄主岩（一般为Rb/Sr <； 10和87Sr/86Sr <； ~ 0.75）。由于土壤主要继承其下伏母岩的87Sr/86Sr值，我们建议在特定地点的土壤地球化学测量中使用这些独特的地球化学指纹来检测地下LCT伟晶岩。我们利用北卡罗莱纳州晚古生代锡锂辉石带和美国威斯康辛州元古代Animikie Red Ace中埋藏的LCT伟晶岩周围和上覆的表层土壤证明了这种方法的潜力和实用性。与远离LCT伟晶岩的背景土壤（87Sr/86Sr ~ 0.74-0.77, Rb/Sr ~ 0.76-3.9）相比，直接覆盖在LCT伟晶岩上的土壤Rb/Sr（~ 10-120）和87Sr/86Sr（~ 1.0-6.8）的比值明显升高，这可以用来识别和重建地下LCT伟晶岩岩脉的位置。全球伟晶岩Rb/Sr和87Sr/86Sr特征的共同和独特的升高表明，该方法可以广泛和全球应用于LCT伟晶岩土壤。

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引用次数: 0

Contrasting cadmium isotope compositions in sediments from the eastern and western new Britain Trench: Implications for source tracing and marine geochemical cycling 新不列颠海沟东部和西部沉积物中镉同位素组成对比：来源示踪和海洋地球化学循环的意义

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-14 DOI: 10.1016/j.apgeochem.2025.106632

Qiang Dong , Cailing Xiao , Yong Liang , Jingqian Xie , Min Luo , Yanwei Liu , Yingying Guo , Yingming Li , Yongguang Yin , Yong Cai , Guibin Jiang

Trench sediments are recognized as a major sink in the marine cadmium (Cd) budget, however, the sources and biogeochemical cycling of Cd in hadal environments remain poorly constrained. This study investigated Cd concentrations and isotope compositions (δ^114/110Cd) in surface sediments (1553–8931 m water depth) from the western and eastern New Britain Trench. Cd concentrations ranged from 105 to 245 μg kg⁻¹, with δ^114/110Cd from −0.26 ‰ to −1.34 ‰, significantly lighter than deep seawater. Isotope tracing reveals that detrital Cd (in the crystalline mineral matrix) accounts for 34–84 % in the western and 64–87 % in the eastern transect. The δ^114/110Cd_non-detrital in shallow sediments differed markedly between western (−0.39 ‰) and eastern (−2.18 ‰) trenches, suggesting distinct sources. Terrigenous inputs, relatively enriched heavy Cd isotopes, dominate in the west, while biogenic particles sinking are likely dominant source in the east. Sedimentary δ^114/110Cd increased in the eastern transect with depth due to stepwise scavenging of light isotopes, whereas in the western transect it first decreased and then increased, reflecting variations in sediment components and redox conditions. These findings underscore the combined effects of source heterogeneity and depositional processes on Cd isotopes composition in trench sediments, offering new insights into deep-ocean metal cycling.

海沟沉积物被认为是海洋镉（Cd）收支的主要汇，然而，对潮环境中Cd的来源和生物地球化学循环的研究仍然很少。本文研究了新不列颠海沟西部和东部表层沉积物（1553 ~ 8931 m水深）中Cd的浓度和同位素组成（δ114/110Cd）。Cd浓度范围为105 ~ 245 μ kg - 1， δ114/110Cd浓度范围为- 0.26‰~ - 1.34‰，显著低于深海。同位素示踪表明，碎屑Cd（在结晶矿物基质中）在西部占34 - 84%，在东部占64 - 87%。西部海沟（- 0.39‰）和东部海沟（- 2.18‰）浅层沉积物δ114/ 110cdnon -碎屑含量差异显著，表明沉积物来源不同。西部以陆源输入为主，重Cd同位素相对富集，东部可能以生物颗粒沉降为主。东部样带沉积δ114/110Cd随深度增大，主要是由于轻同位素的逐步清除作用，而西部样带沉积δ114/110Cd先减小后增大，反映了沉积物组分和氧化还原条件的变化。这些发现强调了来源非均质性和沉积过程对海沟沉积物中Cd同位素组成的综合影响，为研究深海金属循环提供了新的见解。

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引用次数: 0

Qualitative impact of hypersaline wetland on adjacent aquifers: Hydrochemical and isotopic perspectives 高盐湿地对邻近含水层的定性影响：水化学和同位素观点

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-13 DOI: 10.1016/j.apgeochem.2025.106628

Marzieh Kabe, Mohsen Rezaei

Disruption of the natural interaction between groundwater and the Tashk-Bakhtegan Wetland (TBW) has disturbed the dynamic balance of groundwater-surface water systems, increasing the salinity of adjacent groundwater resources. This study investigates the mechanisms of water flow interactions between the TBW in southern Iran and its surrounding aquifers. To investigate the hydrogeochemical processes and salinity mechanisms influencing groundwater near the TBW, 47 water samples were collected from deep and semi-deep wells and the wetland. In situ parameters, including electrical conductivity, temperature and pH, major constituents, and stable isotopes (δ¹⁸O and δ²H) were analyzed in these samples. The spatial distribution of electrical conductivity indicates increasing salinity near the hypersaline wetland. Within a short distance within the aquifers, the water type shifts from Ca–Mg–HCO₃ in recharge boundaries to the domnant water types of Na–Cl. The results indicate that groundwater salinization is driven primarily by reverse ion exchange, mixing with brine, and geological interactions. Hydrogeochemical facies evolution (HFE) models and SO₄/Cl ratios confirm saltwater intrusion into freshwater aquifers. Heavier δ¹⁸O and δ²H ratios in surface water ratios collected from the TBW suggest mixing processes between hypersaline wetland water and meteoric freshwater. The present study may serve as a warning about the vulnerability of adjacent aquifers to salinity intrusion and emphasize the need for sustainable water resource management in the region.

地下水与塔什克-巴赫特干湿地（Tashk-Bakhtegan wetlands， TBW）自然相互作用的破坏，扰乱了地下水-地表水系统的动态平衡，增加了邻近地下水资源的盐度。本研究探讨了伊朗南部TBW及其周围含水层之间水流相互作用的机制。为了研究三峡库区附近地下水的水文地球化学过程和盐度影响机制，采集了47个深井、半深井和湿地水样。分析了样品的电导率、温度、pH、主要成分、稳定同位素δ18O和δ2H等原位参数。电导率的空间分布表明，高盐湿地附近盐度增加。在含水层内短距离内，补给边界的水类型由Ca-Mg-HCO3转变为Na-Cl的优势水类型。结果表明，地下水盐渍化主要是由反向离子交换、与盐水混合以及地质相互作用驱动的。水文地球化学相演化（HFE）模型和SO4/Cl比值证实咸水侵入淡水含水层。TBW收集的地表水比率中δ18O和δ2H比值较大，表明高盐湿地水与大气淡水之间存在混合过程。本研究可作为邻近含水层对盐度入侵的脆弱性的警告，并强调该地区可持续水资源管理的必要性。

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引用次数: 0

Biased selection and incomplete characterization of feedstock materials in enhanced rock weathering experiments 强化岩石风化实验中原料选择的偏差和表征的不完整

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-12 DOI: 10.1016/j.apgeochem.2025.106630

Benjamin Möller , Xavier Dupla

Terrestrial Enhanced Rock Weathering (ERW) – the application of crushed rocks to soils to accelerate CO₂ removal – has emerged as a promising climate mitigation strategy to complement emission reduction efforts. One of the key factors controlling the efficacy of ERW is the composition of the utilized rock powder, ultimately constraining the achievable CO₂ removal potential and rate in a given environment. In this article, we highlight that experimental research on ERW is dominated by a narrow range of commercially available rock powders, arguably often selected more for convenience than for relevance. These materials are often poorly characterized, neglecting core methods and principles of petrography. In combination, these shortcomings are detrimental to our understanding of ERW's potential and our ability to guide its successful implementation. We call for a systematic and detailed evaluation of all potential feedstocks, going beyond readily available products. In doing so, we hope to better constrain experimental results and inform on ERW's overall CO₂ removal capacity.

陆地增强岩石风化（ERW）——将碎石应用于土壤以加速二氧化碳的去除——已成为一项有希望的气候缓解战略，以补充减排努力。利用的石粉的组成是影响废渣处理效果的关键因素之一，最终限制了在给定环境下可实现的CO2去除潜力和速率。在这篇文章中，我们强调，对战争残留物的实验研究主要是由一个狭窄的范围内的市售岩石粉末，可以说往往选择更多的方便而不是相关性。这些材料的特征往往很差，忽略了岩石学的核心方法和原理。综合起来，这些缺点不利于我们理解战争遗留爆炸物的潜力，也不利于我们指导其成功实施的能力。我们呼吁对所有潜在的原料进行系统和详细的评估，而不仅仅是现成的产品。通过这样做，我们希望更好地约束实验结果，并提供有关ERW整体二氧化碳去除能力的信息。

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引用次数: 0

Reconstructing coalbed methane accumulation history in the Qinshui Basin using noble gas isotopes 利用稀有气同位素重建沁水盆地煤层气成藏史

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-12 DOI: 10.1016/j.apgeochem.2025.106629

Zhelin Zhang , Biying Chen , Yi Liu , Zhanjie Xu , Finlay M. Stuart , Sheng Xu

Coalbed methane (CBM) is an unconventional natural gas resource that supports low-carbon energy demand and mitigates greenhouse gas emissions during coal mining. It is a key natural gas resource in China. Understanding how CBM is produced and accumulates is critical for exploration. Qinshui Basin is the largest and most productive CBM basin in China. This study uses the light noble gas compositions (He, Ne and Ar) of CBM from five blocks in the Qinshui Basin to provide a comprehensive view of gas accumulation history. The noble gases are derived from air and deep crustal sources. Gases from these sources were mixed in formation water prior to methane extraction. Subsequent degassing followed open-system Rayleigh fractionation, enabling the crustal ⁴He and ⁴⁰Ar accumulation ages and the gas-water interaction volume to be determined, as well as the proportion of desorbed methane released during production. The coal seams have incorporated the flux of ⁴He and ⁴⁰Ar from the deep crust. Despite this, the crustal ⁴He and ⁴⁰Ar accumulation ages are considerably younger than the Permo-Carboniferous coal deposition age, revealing widespread gas loss. Adsorbed methane was released during gas extraction. The proportion of desorbed methane in the produced gas shows a strong relationship with crustal ⁴⁰Ar accumulation ages, indicating that the noble gases serve as a proxy for the preservation of adsorbed methane. The interacted gas/water ratios derived from air-sourced noble gases reflect the extent of gas extraction. Low extraction efficiency is indicated by low gas/water ratios, high dilution ratios and low gas production rates, while prolonged high extraction rates lead to a decline in the dilution ratio. These findings demonstrate the value of measuring trace noble gases for understanding gas accumulation and guiding CBM production strategies.

煤层气（CBM）是一种非常规的天然气资源，可以满足低碳能源需求，减少煤炭开采过程中的温室气体排放。它是中国重要的天然气资源。了解煤层气如何产生和积累对勘探至关重要。沁水盆地是中国最大、产量最高的煤层气盆地。利用沁水盆地5个区块煤层气的轻稀有气组成（He、Ne、Ar），全面了解沁水盆地煤层气成藏历史。稀有气体来自空气和地壳深处。在提取甲烷之前，将这些来源的气体混合到地层水中。随后的脱气采用开放体系瑞利分馏，可以确定地壳4He和40Ar聚集年龄、气水相互作用体积以及生产过程中释放的解吸甲烷比例。煤层吸收了来自地壳深部的4He和40Ar通量。尽管如此，地壳4He和40Ar聚集年龄比二叠石炭系煤沉积年龄要年轻得多，显示出广泛的气体损失。在气体提取过程中，被吸附的甲烷被释放。解吸甲烷在产出气中所占比例与地壳40Ar成藏年龄密切相关，表明稀有气体代表了吸附甲烷的保存。气源惰性气体的气/水相互作用比反映了气体提取的程度。低萃取效率表现为低气水比、高稀释比和低产气率，而长时间高萃取导致稀释比下降。这些发现证明了微量稀有气体的测量对于了解天然气聚集和指导煤层气生产策略的价值。

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引用次数: 0

Estimation of flow dynamics of saline groundwater in a coastal geothermal region based on B–Li–Cl classification and geochemical measurements 基于B-Li-Cl分类和地球化学测量的滨海地热区含盐地下水流动动力学估算

IF 3.4 3区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Applied Geochemistry

Pub Date : 2025-11-12 DOI: 10.1016/j.apgeochem.2025.106625

Tsuyoshi Shintani , Keiichi Tomita , Noritoshi Morikawa

Coastal geothermal saline groundwater (SGW) in Quaternary volcanic regions represents an important geothermal resource, but its complex chemical compositions often obscure its origin and dynamics. This study aims to elucidate the SGW dynamics in the coastal plain of Hakodate, Hokkaido, in Japan using the B–Li–Cl to delineate water-rock interactions and diagenesis, and to classify SGW type. Major dissolved components and stable isotopes (δ²H, δ¹⁸O) are susceptible to freshwater dilution, limiting their diagnostic utility. The B–Li–Cl composition allowed for the classification of SGW into three types (Type 1, 2, and 3). Types 1 and 2 were influenced by direct seawater contributions and other origins such as diagenesis and volcanic gas, respectively. Type 3, with higher B (Boron) and Li (Lithium) concentrations than the other SGW, is distributed in the geothermal region, and reflects seawater modified by interaction with rocks at 175 ± 25 °C. Integration of chemical equilibrium modeling and geothermometer supports this geochemical evolution of the SGWs. Additionally, hydrogeological analyses have estimated that the flow dynamics of Type 3 waters are recharged through fractures near offshore submarine volcanic vents that migrate to deeper subsurface regions. These findings offer new insights into coastal hydrothermal systems in the study area. The Li and B concentrations serve as effective tracers for elucidating the origin of SGW in coastal geothermal regions, and their application is expected to lead to a more comprehensive understanding of SGW flow dynamics.

第四纪火山岩区沿海含盐地热地下水是一种重要的地热资源，但其复杂的化学成分往往使其起源和动态变得模糊不清。本研究旨在利用B-Li-Cl描述日本北海道函馆沿海平原的水-岩相互作用和成岩作用，并对SGW类型进行分类。主要溶解成分和稳定同位素（δ2H, δ18O）易受淡水稀释的影响，限制了它们的诊断效用。B-Li-Cl组成允许将SGW分为三种类型（类型1,2和3）。类型1和类型2分别受到海水直接贡献和成岩作用、火山气等其他成因的影响。类型3分布在地热区，B （Boron）和Li （Lithium）的浓度高于其他SGW，反映了175±25℃时海水与岩石相互作用的改变。化学平衡模型和地温计的结合支持了SGWs的地球化学演化。此外，水文地质分析估计，3型水的流动动力学是通过海上海底火山口附近的裂缝补充的，这些裂缝迁移到更深的地下区域。这些发现为研究区沿海热液系统提供了新的认识。Li和B浓度是阐明沿海地热区SGW成因的有效示踪剂，它们的应用有望使人们对SGW流动动力学有更全面的了解。

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引用次数: 0