Geothermics最新文献

{"title":"Tectonic controls and earthquake response of thermal fluid geochemistry in southern Yunnan, southeastern Tibetan Plateau","authors":"Chenhua Li ,&nbsp;Xiaocheng Zhou ,&nbsp;Miao He ,&nbsp;Zhaojun Zeng ,&nbsp;Yuwen Wang ,&nbsp;Jiao Tian ,&nbsp;Yucong Yan ,&nbsp;Bingyu Yao ,&nbsp;Hejun Su ,&nbsp;Ruigang Li","doi":"10.1016/j.geothermics.2025.103568","DOIUrl":"10.1016/j.geothermics.2025.103568","url":null,"abstract":"<div><div>Geochemical variations in thermal spring compositions are sensitive to changes in regional stress, temperature, and space conditions, which are indicators of seismic and tectonic activities. However, the temporal and spatial variations in water chemistry components and their inducing mechanisms are insufficiently understood. This study aims to evaluate the effective temporal coincidence/lag of seismic events based on the long-term continuous water chemistry monitoring of seismic areas and draw attention to water chemistry changes in thermal waters during earthquake hazard monitoring. We investigated the major elements, trace elements, and hydrogen and oxygen isotopes of 21 thermal springs along the Lancang–Gengma fault (LGF) zone, which is in a highly deformed, seismically active area of the Southeastern margin of the Tibetan Plateau. In the LGF zone, the temperatures of the studied thermal springs range from 44.7°C to 96.2°C. The reservoir temperatures range from 91°C to 195°C and the reservoir depth range from 4–9 km. According to the spatiotemporal chemical variations from two-year regular monitoring of Na⁺, Cl⁻, F⁻, SO₄²⁻, Li, B, δD, and δ¹⁸O in five thermal springs, the thermal springs in these fault-controlled areas are sensitive and responsive to seismic activity. Different tectonic regions exhibit significant and diverse short-term precursory anomalies in water chemistry before earthquakes with <em>M</em> ≥ 5.0. Their characteristics and mechanisms are region-specific, and the study area is divided into two monitoring capacity range areas. Area 1: The MG, MM and XF monitoring points located on the Baoshan block are highly sensitive to seismic responses in the SW direction of the study area. For example, continuous Na⁺, Cl⁻, SO₄²⁻and F⁻ anomalies were observed in MG, MM and XF before the <em>M</em>_L5.0 and <em>M</em>_L5.9 Myanmar earthquakes (southwest of the study area). Area 2: The NKL and EL monitoring points located on the Simao block are highly sensitive to seismic responses in the SE direction. For instance, the Na⁺ concentrations in EL and NKL sharply increased above the normal threshold before the <em>M</em>_L6.2 Laos earthquake and <em>M</em>_L5.0 Honghe earthquake. Notably, significant spatial directional differences in fluid chemical responses to earthquakes were observed. This directional difference may be related to the complexity of the regional stress field in the area and the local characteristics of fault activities. The chemical composition changes of these thermal springs during fluid circulation in the LGF can be a good tracer of seismic activity.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103568"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How useful are outcrop samples to constrain subsurface thermal properties for geothermal exploration? Case study from the Chester formation, UK","authors":"Maëlle Brémaud ,&nbsp;Neil M. Burnside ,&nbsp;Zoe K. Shipton ,&nbsp;Claire Bossennec ,&nbsp;Sven Fuchs ,&nbsp;Fiorenza Deon","doi":"10.1016/j.geothermics.2026.103617","DOIUrl":"10.1016/j.geothermics.2026.103617","url":null,"abstract":"<div><div>Hot sedimentary aquifers (HSAs) offer a sustainable option for geothermal energy, but exploration risks remain a major challenge. Drilling is capital intensive, especially for geothermal projects, and early in project appraisal it is often uncertain whether a formation will provide sufficient thermal performance to justify investment. Outcrop samples have therefore gained attention as analogues for subsurface reservoir properties, providing low-cost preliminary data before committing to drilling. While this approach is well established in the hydrocarbon industry, its application to geothermal settings has been limited. Existing geothermal studies have largely focused on structural, petrophysical, or mineralogical characterisation, while systematic comparisons of these properties and thermal properties between outcrop and core samples remain rare. This is a critical gap, as thermal properties govern the long-term performance of a geothermal system. This study compares seventeen outcrop and twenty-one core samples (taken from depths of 22–96 m) from the Triassic Chester Formation in the Cheshire Basin, UK, to assess the transferability of outcrop-derived data. The samples were analysed for mineralogy, petrophysical, and thermal properties. Results show that while outcrop samples exhibit some variability due to weathering at the Earth’s surface, they generally have similar mineralogical and petrophysical properties to core samples. Thermal conductivity is higher in cores (2.15 ± 0.01 W m⁻¹ K⁻¹) compared to outcrops (1.74 ± 0.01 W m⁻¹ K⁻¹). Variations are also observed between different lithotypes, with pebble-rich samples generally exhibiting higher thermal conductivity than massive, layered, or cross-bedded sandstones. These findings highlight the potential of outcrop samples for early-stage geothermal exploration. They provide a cost-effective alternative to drilling for constraining rock properties, particularly thermal conductivity, at depth, while offering insights into depositional environment and lithology. This integrated approach could improve subsurface predictions, reduce exploration costs, and support the growth of the geothermal sector by de-risking investment decisions.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103617"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real scale evaluation of geothermal heat exchanger performances integrated to poultry house","authors":"Oussama Zobiri ,&nbsp;Abdelmalek Atia ,&nbsp;Müslüm Arıcı","doi":"10.1016/j.geothermics.2025.103553","DOIUrl":"10.1016/j.geothermics.2025.103553","url":null,"abstract":"<div><div>There is a growing body of literature that recognizes the importance of Heating, Ventilation and Air Conditioning systems (HVAC) based on ground to air heat exchangers (GAHEs). In the present experimental work, real field experimental setup of GAHEs to study the air quality of GAHE outlet inside a poultry house compared with air ambient and the conventional poultry house (CPH). Results showed that mean air temperature of heat exchanger at the outlet is stable, which remains closer than 24.2 °C, and the average GAHE efficiency is reached 92 % during the experiment period. GAHE maintains an average relative humidity of around 32 % due to the movement and rotation of air stream caused by the fan. GAHE plays a positive role in the ventilation process of the poultry house, as it renews the amount of air inside the poultry room during the study period. One of the more significant findings to emerge from this study is that the Carbon dioxide (CO₂) concentration inside the poultry house integrated with geothermal heat exchangers is less than the concentration that exists in conventional one by 400 parts per million (ppm). The application of geothermal energy systems in buildings holds great potential due to its availability, being considered naturally free and sustainability contributions.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103553"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145685387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-dimensional lithospheric-scale thermal model as supporting tool for new exploration campaigns for geothermal resources: Insights from the Calabria region (Southern Italy)","authors":"G. Vespasiano ,&nbsp;G. Floridia ,&nbsp;M. Giuffrida ,&nbsp;M. Viccaro ,&nbsp;A. Bloise ,&nbsp;R. De Rosa ,&nbsp;M. Cacace ,&nbsp;I. Fuoco ,&nbsp;M.F. La Russa ,&nbsp;F. Muto ,&nbsp;R. Dominici ,&nbsp;L. Russo ,&nbsp;M. Cipriani ,&nbsp;A. Guido ,&nbsp;G. Maruca ,&nbsp;C. Apollaro","doi":"10.1016/j.geothermics.2026.103604","DOIUrl":"10.1016/j.geothermics.2026.103604","url":null,"abstract":"<div><div>This study presents the first lithosphere-scale, steady-state 3D thermal model of the Calabria region (Southern Italy), developed to support the geothermal resource assessment and exploration. By integrating geological, geophysical, and thermal datasets, a high-resolution 3D geological model was built and used as a structural framework for finite-element thermal simulations. The simulations incorporated spatially variable thermal conductivity, radiogenic heat production, and a range of basal heat flux values applied at the crust-mantle (Moho) interface. Five thermal scenarios were tested and calibrated against 254 measured temperature data points from exploration wells. The results reveal pronounced lateral thermal heterogeneity, with temperatures exceeding 90 °C at 3 km depth beneath the Ionian basins, driven by the local crustal structure, sedimentary blanketing, and Moho geometry. While the model delineates zones suitable for low-to-medium enthalpy geothermal exploitation (1-3 km), deeper high-enthalpy targets remain less constrained and deserve further investigation. This study establishes a geologically consistent framework that enhances the understanding of the regional thermal regime and serves as a strategic tool for guiding future geothermal exploration in Calabria.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103604"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cenozoic tectonic-thermal evolution of the Xihu Sag, East China Sea Basin: Implications for hydrocarbon generation in continental margin basins","authors":"Qiwen Yao ,&nbsp;Hui Diao ,&nbsp;Jian Chang ,&nbsp;Wu Zhang ,&nbsp;Ruiheng Zhan ,&nbsp;Hangyuan Gao ,&nbsp;Kefu Li","doi":"10.1016/j.geothermics.2025.103530","DOIUrl":"10.1016/j.geothermics.2025.103530","url":null,"abstract":"<div><div>This study investigates the Cenozoic tectono-thermal evolution of the Xihu Sag in the East China Sea Basin, a rift–inversion sub-basin at the convergent boundary of the Eurasian, Pacific, and Philippine Sea plates. The findings have broad implications for hydrocarbon generation and thermal history reconstruction in similar continental margin basins globally. By integrating present-day geothermal data, low-temperature thermochronology, vitrinite reflectance, and fluid inclusion analysis, this study reconstructs the thermal history and source rock maturation processes in the Xihu Sag. The geothermal gradient ranges from 16 to 46 °C/km at depths of 0–4 km, with an average of 31.8 °C/km, and surface heat flow varies between 34 and 88 mW/m², averaging 52.3 mW/m². These thermal regimes show a southeast-high to northwest-low trend, primarily influenced by lithospheric thinning, thermal refraction, and basement morphology. Thermal history modeling reveals a significant cooling event during the Late Miocene (14–7 Ma), corresponding to the Longjing tectonic phase, with progressive southeast-to-northwest deformation. Erosion magnitudes exceeded 800 m in marginal anticline zones, while the central Pinghu Slope Belt experienced denudation rates up to 246 m/Ma. Basin modeling indicates that basement heat flow decreased during the Early to Middle Miocene but increased again during tectonic inversion, significantly influencing source rock maturation. The Pinghu Formation source rocks reached peak hydrocarbon generation by the end of the Miocene. Fluid inclusion data indicate two primary hydrocarbon charging phases (∼15–9 Ma and ∼5–0 Ma), consistent with modeled expulsion stages. This study introduces a robust, multi-parameter integrated framework to rigorously assess the geothermal state, tectonic characteristics, and petroleum generation potential of continental margin basins. This methodological paradigm shift fundamentally advances the approaches to thermal history reconstruction and hydrocarbon exploration, providing a reliable and universally applicable solution for analogous geological settings.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103530"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D resistivity model of the los Humeros geothermal field in Mexico, based on magnetotelluric data","authors":"José M. Romo-Jones ,&nbsp;Claudia Arango-Galván ,&nbsp;Diego Ruiz-Aguilar ,&nbsp;Gylfi Páll Hersir ,&nbsp;Ásdís Benediktsdóttir ,&nbsp;José L. Salas-Corrales ,&nbsp;Thalia A. Esquivel-Avilés ,&nbsp;Sebastian Held","doi":"10.1016/j.geothermics.2025.103591","DOIUrl":"10.1016/j.geothermics.2025.103591","url":null,"abstract":"<div><div>A joint geothermal project of a European and Mexican consortium (the GEMex project) was carried out between 2016 and 2020 to develop geothermal energy in the easternmost region of the Trans-Mexican Volcanic Belt. GEMex project was funded by the European Union’s Horizon 2020 and SENER-CONACYT Mexican Energy Sustainability programs. One of the key outcomes is the 3D resistivity model of the Los Humeros geothermal field in Mexico, a potentially superheated geothermal reservoir, where fluid temperature reaches close to 400 °C in some areas, based on magnetotelluric (MT) data. The model reveals a shallow resistive zone linked to post-caldera volcanic rocks; underlying this horizon is an updoming conductive anomaly caused by smectite-rich hydrothermally altered rocks that act as cap-rock. Beneath this seal-cap, a deep dome-shaped resistive anomaly is observed, likely corresponding to andesitic reservoir rocks (50–100 Ohm-m) and deeper basement rocks, possibly limestone and granodiorite. This structure aligns with temperature measurements from boreholes, where the 250–300 °C isotherms follow the shape of the top of the resistive dome. The obtained 3D model successfully identifies deep faults that facilitate hot fluid circulation and define the structural limits of the Los Potreros caldera. Faults within the caldera collapse significantly disrupt the cap-rock and the top of the andesites that host the reservoir. This information, together with results derived from other geophysical, geological, and geochemical methods, will help to infer the location and depth at which high-temperature fluids might be found.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103591"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical behavior and constitutive model of thermally damaged granite: Insights from experiments","authors":"Ming Min ,&nbsp;Qiang Zhang ,&nbsp;Xiao-Suo Wu ,&nbsp;Bin-Song Jiang","doi":"10.1016/j.geothermics.2026.103602","DOIUrl":"10.1016/j.geothermics.2026.103602","url":null,"abstract":"<div><div>The growing development of deep geothermal energy resources, where rock masses are subjected to high temperatures and significant plastic deformation, demands constitutive models that accurately capture this complex behavior. This study presents a novel thermomechanical constitutive model within a strain-softening framework, which uniquely integrates the coupled effects of temperature (<em>T</em>), confining pressure (<em>σ</em>₃), and plastic shear strain (<em>γ</em>^p). Its primary innovation lies in explicitly formulating the cohesion (<em>c</em>), internal friction angle (<em>φ</em>), and dilation angle (<em>ψ</em>) as functions of both <em>γ</em>^p, <em>T</em> and/or <em>σ</em>₃. This nonlinear evolution function is is underpinned by systematic triaxial compression tests on thermally-treated granite specimens, which reveal that <em>c, φ</em>, and <em>ψ</em> undergo initial increasing followed by an exponential decay with increasing <em>γ</em>^p. Notably, <em>T</em> and <em>σ</em>₃ play a critical role in modulating the evolution law of these fitting parameters. The proposed model, implemented in FLAC3D via a secondary development scheme, successfully reproduces the nonlinear deformation and strain-softening behavior observed in experiments. An engineering case study demonstrates that conventional models assuming constant temperature (<em>T</em> = 25°C) underestimate radial displacements around a deep circular opening by up to 188%, compared to simulations incorporating the proposed model with a realistic nonlinear thermal field. These findings emphasize the critical importance of incorporating thermo-mechanical-plastic coupling in the design and analysis of deep geothermal environments.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103602"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrogeochemical characteristics and geological controls of thermal springs in the Chengde Area, North China","authors":"Yixuan Wang ,&nbsp;Xun Zhou ,&nbsp;Jingru Ma ,&nbsp;Bin Fang ,&nbsp;Ye Shen ,&nbsp;Ruige Chen ,&nbsp;Yanqiu Wu ,&nbsp;Yanxiang Shi ,&nbsp;Mengying Chen ,&nbsp;Qiqi Liu ,&nbsp;Tong Zhang ,&nbsp;Guangbin Tao ,&nbsp;Linyang Zhuo","doi":"10.1016/j.geothermics.2026.103600","DOIUrl":"10.1016/j.geothermics.2026.103600","url":null,"abstract":"<div><div>Hot springs in the Chengde region of northern Hebei Province, China, occur in scattered locations influenced by varied geological structures. Twenty-eight water samples from 10 sites were analyzed to investigate hydrogeochemistry and geothermal behavior. Stable isotopes indicate meteoric recharge at elevations of 861–1938 m, with northern springs near active faults showing more depleted signatures, reflecting deeper circulation. The waters are weakly alkaline, low- to moderate-TDS, and mainly HCO₃·SO₄–Na and HCO₃–Na types. Na⁺ derives from silicate weathering and cation exchange, SO₄^2- from evaporite dissolution and pyrite oxidation, and HCO₃^- from CO₂-driven carbonate dissolution. Trace elements (Li, Rb, Cs, Sr, Ba) vary systematically among groups, indicating differences in reservoir lithology and circulation depth; carbonate dissolution is a major Sr and Ba source. Mineral saturation and ion concentrations reflect contrasting water–rock interaction intensities. Reservoir temperatures from silica geothermometers and the SiO₂–enthalpy model range from 50 to 143 °C, with circulation depths up to approximately 4500 m and cold water mixing ratios of 46–93%. Springs linked to faults and lithological contacts generally have higher temperatures and deeper flow paths, whereas those in bedrock fractures are shallower and more affected by mixing. These findings highlight the combined influence of topography, geological structure, and lithology on geothermal circulation, providing a geochemical framework for geothermal exploration and resource assessment in intracontinental regions.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103600"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanisms underlying sulfate concentration variations in geothermal waters around the Wugongshan area","authors":"Li Gong ,&nbsp;Zheming Shi ,&nbsp;Ximin Bai ,&nbsp;Yunfei Bai ,&nbsp;Jue Tong ,&nbsp;Bangmin Li","doi":"10.1016/j.geothermics.2025.103550","DOIUrl":"10.1016/j.geothermics.2025.103550","url":null,"abstract":"<div><div>Understanding the sources of sulfate in geothermal waters is crucial for elucidating hydrothermal cycling mechanisms and the pathways of sulfur transport and transformation within hydrothermal systems. Distinct SO₄^2– concentrations have been observed in the eastern and western sections of the Wugongshan hydrothermal system; however, the origins and mechanisms of these variations remain unexplored. In this study, a combined hydrogeochemical and microbial analysis was conducted on 11 samples collected from geothermal wells across the Wugongshan geothermal field. The results indicated that silicate weathering, particularly feldspar dissolution influenced by CO₂, was the dominant geochemical process in Wugongshan’s geothermal waters. The western samples (XQ and ZK08) exhibited minimal cold-water dilution during ascent, preserving distinct hydrogeochemical signatures. Eight types of sulfur-oxidizing genes were identified, with XQ and ZK08 showing the highest abundances. Strong correlations existed between microbial taxa (e.g., Thiovirga, Thiobacillus in XQ; Tepidimonas, Meiothermus in ZK08), functional genes (fccAB, dsrABC, sox clusters), and SO₄^2– production. Microbial metabolic pathways were the primary drivers of SO₄^2– variation across the region. In the eastern Wugongshan samples, SO₄^2– was sourced exclusively from gypsum dissolution, whereas in the west, microbially mediated sulfide oxidation (e.g., pyrite and H₂S) dominated SO₄^2– generation. This study aims to delineate the mechanisms behind sulfate concentration variations in geothermal waters of the Wugongshan area, with particular focus on microbial and mineralogical contributions.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103550"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145685386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geothermal resources pathways: the hydrochemical evolution and genesis of geothermal waters in the Xianshuihe fault Zone, eastern Qinghai-Xizang plateau","authors":"Yunhui Zhang ,&nbsp;Jinhang Huang ,&nbsp;Xingze Li ,&nbsp;M. Santosh ,&nbsp;Ying Wang ,&nbsp;Xingcheng Yuan ,&nbsp;Yangshuang Wang ,&nbsp;Hongyang Guo ,&nbsp;Xiaoyan Zhao ,&nbsp;Xun Huang","doi":"10.1016/j.geothermics.2025.103551","DOIUrl":"10.1016/j.geothermics.2025.103551","url":null,"abstract":"<div><div>Exploiting and utilizing geothermal resources require a clear understanding of their genesis mechanisms. Regional fault zones often host abundant geothermal resources whose genesis connections are not well understood. This study aims to elucidate the hydrochemical properties and formation mechanisms of diverse geothermal systems within the Xianshuihe Fault Zone (XFZ), eastern Qinghai-Xizang Plateau. The Self-Organizing Maps and Positive Matrix Factorization algorithms, hydrochemical analysis, and hydrogen-oxygen isotope analysis were employed to identify the intrinsic genesis connections among different types of geothermal waters in the XFZ. The geothermal waters along the XFZ were classified into three groups (Groups 1 − 3). Group 1 is predominantly Cl-Na and Cl·HCO₃-Na types; Group 2 is of HCO₃-Na and SO₄·HCO₃-Na types; and Group 3 primarily belongs to HCO₃-Na and HCO₃-Ca types. The primary source of geothermal water in Groups 1–3 is from fluids stored in deep granitic reservoirs, accounting for 40.1%, 28.8%, and 25.0% in each respective group. The secondary source is the infiltrating cold water leaching the shallow sedimentary rock, contributing 33.5%, 23.6%, and 25.7%, respectively. The primary sources of recharge for the geothermal water in the study area are snow-melting and meteoric water. Group 1 exhibits the highest reservoir temperatures (124.5 °C to 224.1 °C), followed by Group 2 (93.6 °C to 191.7 °C), and Group 3 (75.1 °C to 164.2 °C). This study indicates that the spatial distribution of geothermal water from Group 1 ('Deep Initial Geothermal Water') to Group 2 ('Evolved Shallow Geothermal Water') and Group 3 ('Mixed Shallow Geothermal Water') is a common phenomenon along the XFZ. Based on these findings, this study establishes a conceptual model for different groups of geothermal waters, which also helps establish interconnections among geothermal systems in regional fault zones.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"136 ","pages":"Article 103551"},"PeriodicalIF":3.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145685388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}