Italy has a long history of geothermal use, but a comprehensive, updated national assessment has been lacking. This study is the first to systematically evaluate geothermal resources across Italy using the modern geothermal play concept. The primary objective is to provide a standardized, transparent, and reproducible basis for comparing geothermal resources within Italy and across European geological settings. The assessment combines geological, tectonic, geothermal, and utilization data within a GIS framework to map geothermal play types, distinguishing convection- and conduction-dominated systems. Twenty-seven plays are identified and grouped into six main types: volcanic, plutonic, and extensional domains as convection-dominated play types, and foreland basins, orogenic belt, and basement rock provinces as conduction-dominated play types. They form the first geothermal play type map for Italy. From these, 17 key play reservoirs were analyzed using borehole temperature data, lithostratigraphy, reservoir geometries, and petrophysical parameters derived from published literature. Geothermal potential was estimated through volumetric methods for Heat in Place (HIP) and, where possible, Heat Storage Potential (HSP) for medium- and high-temperature Aquifer Thermal Energy Storage (ATES). Probabilistic Monte Carlo simulations addressed uncertainties. Results highlight the exceptionally high geothermal potential of traditional, convection-dominated, plutonic systems in Tuscany, where all power plants are currently operating. In parallel, conduction-dominated sedimentary basins—especially within the Po Plain—exhibit significant potential for direct heat use and thermal energy storage, supported by large reservoir volumes and favorable petrophysical properties. Given the broad distribution of this play type, geothermal resources in Italy have significant potential that extends well beyond traditional magmatic areas. The proposed national framework provides a robust basis for geothermal energy planning, supports cross-border comparison within Europe, and identifies priority targets for future exploration, direct heat utilization, and large-scale subsurface thermal energy storage.

The geothermal sector generates a vast amount of knowledge—from research project data to scientific publications, technical reports, patents, and open datasets—produced by scientists, operators, consultants, public authorities, and funding agencies. However, this wealth of information is often scattered across multiple repositories and platforms, which hampers effective access, integration, and utilization. EGRISE 2.0, developed within the EU-funded Geotherm-FORA project, addresses this challenge as the largest thematic repository for geothermal research and innovation in Europe. The platform aggregates information from EU-funded projects, open access publications, scientific journals, and public datasets hosted on repositories such as Zenodo and Pangaea. Each research product is indexed with detailed metadata, enabling users to search, filter, and explore thousands of documents—currently over 11,000—by criteria such as publication type, funder, country, year, language, or resource access.By consolidating this vast body of knowledge and facilitating its exploration, EGRISE 2.0 allows stakeholders to precisely map the state of R&D in the geothermal industry. Researchers can spot emerging trends, identify gaps, and recognize key contributors, while funding agencies and policymakers can evaluate technological maturity and set priorities for future research and investment. Additionally, the platform facilitates the preparation of innovative project proposals by offering instant access to scientific publications, datasets, and project deliverables.A set of integrated charts further enhances the platform’s value, offering insights such as publication trends, openness over time, and data FAIRness. EGRISE is an open tool available at https://egrise.openaire.eu/. It is powered by OpenAIRE CONNECT, a service to build customizable search portals on top of the OpenAIRE Graph, one of the largest open scientific knowledge graph. In this way, EGRISE 2.0 not only consolidates knowledge but actively empowers innovation, collaboration, and strategic decision-making leveraging on open research information, establishing itself as an indispensable tool for the European geothermal community.

Recent advancements in laboratory implementation and instrumentation have led to the generation of increasingly abundant data, with the need for greater collaboration and data sharing. To address this challenge, the expansion of e-infrastructures and the development of Virtual Research Environments (VREs) have become essential.VREs provide an integrated ecosystem for data collection, analysis, and publication, following the Open Science principles, of transparency, inclusion, integrity, and collaboration. VREs are based on the D4Science e-infrastructure, which promotes collaboration and cooperative work among the scientific communities and the stakeholders identified by the researchers.In the framework of the ITINERIS Project, the new comprehensive Italian Research Infrastructures (RIs) hub in the geoscientific and environmental fields, several multidisciplinary teams are developing thematic VREs for studying the entire Earth System, by combining field and lab measurements, data analysis, and modelling tools across all the environment domains.Among the VREs, the “Critical Zone (CZ) VRE” is specifically designed for collecting datasets and information from the Critical Zone Observatories (CZOs, active in Italy and abroad) primarily managed by Italian research teams and including tools for data visualization and analysis, as well as models useful for studying the complex dynamics of the Critical Zone.The Critical Zone represents the thin layer between the unweathered bedrock and the top of the vegetation canopy, where “rock meets life”. It includes rocks, soil, water, microbiota, vegetation and fauna, along with the services they provide to humankind and all the processes supporting terrestrial ecosystems and the soil-vegetation-atmosphere interactions.D4Science-enabled Critical Zone VRE offers a set of tools supporting all the steps of the research lifecycle, from data collection to data analysis, and visualization. Data collection and dataset assembly are fostered by the Collaborative Storage Framework, which promotes teamwork among users and offers a collaborative space to share digital objects. For data analysis, the Critical Zone VRE is equipped with an Analytics Engine Framework, which includes Cloud Computing Platforms (CCPs), as well as the DataMiner. Additionally, the Critical Zone VRE is equipped with RStudio 4 and JupyterLab. These tools enable the development of specific codes (in various free-license programming languages) and models that can be launched directly from the VRE to analyze and visualize data. Data publishing of research outcomes is also facilitated by the development of metadata and spatial data catalogues. In particular, the catalogues help to organize and make research outcomes available to the broader scientific and multidisciplinary community.Further improvements in studying Critical Zone components and dynamics are essential, and in this case, valuable support can be gained through the interaction between the Critical Zone VRE and other VREs. An example is the interaction with the Isotope VRE, which contains a dedicated web application for analysis and modelling (called “Isotope Studio”) and aims to represent the first Italian database on environmental isotopes, allowing researchers and environmental managers to interpret and model bio-geochemical processes in the framework of the Environmental Sciences.

Collapsed calderas are prominent volcano-tectonic features occurring in active tectonic settings and bear intrinsic risks associated with their explosiveness. Nonetheless, they also represent key targets for geothermal fluid exploration, their structures being often the preferential pathway for geothermal fluids migration. In active tectonic settings such as continental rifts, caldera faults may be reactivated, enhancing therefore their permeability. However, specific structures may be subject to clamping, consequently reducing their secondary porosity. Discriminating if and how caldera structures may respond to tectonic stresses, represents therefore a critical question to address when calderas become the locus of potential geothermal exploration. We performed an experimental series of analogue models of caldera collapse exploring whether caldera structures may reactivate under extensional tectonic conditions. This analysis is important for evaluating which caldera fault segments may be regarded as the best potential target for fluid interception. Our experimental series shows that regional extension and fault dip can explain the reactivation of specific caldera fault segments. In particular, outer normal ring faults do reactivate under extensional conditions only in the sectors trending orthogonally to the direction of extension. Conversely, inner outward-dipping reverse faults do not reactivate, likely because of their lower dip angle, whichever their trend might be. This implies that inward-dipping normal faults trending orthogonal to direction of extension likely increase their permeability, thus becoming a favourable locus for geothermal fluid migration and therefore a preferable target for exploration. Conversely, our models show that sectors of inward-dipping normal caldera faults trending parallel to the direction of extension may experience clamping, and so reducing their secondary permeability. Therefore, our setup, with due approximations and limitations, represents a useful predictive tool for identifying potential target structures for geothermal exploration at caldera sites. The model setup can also provide insights into similar caldera systems developing in other geological settings (e.g., compressional).

Applications of conventional isotopes (e.g., H, O, C, N, and S), as well as non-conventional (e.g., B, Li, Fe, Cu, Zn, and Mg) and radiogenic isotopes (e.g., Sr, Nd, and Pb), offer unique opportunities to evaluate deep geological processes, environmental processes and their interactions within the Critical Zone (CZ). Human-induced climate change represents one of the most pressing environmental challenges of the twenty-first century; in the light of this, isotopic composition analysis provides an effective means to investigate it. Numerous studies have highlighted the fundamental role of isotope geochemistry in understanding environmental systems to critical zone processes, and the volume of research in this field continues to grow. Considering this, a comprehensive inventory of stable and radiogenic isotopes has become essential for tracking processes involving fluids, minerals, rock evolution, and origin, as well as examining interactions in soils, plants, and other reservoirs. Currently, data and information are unevenly distributed across various sources and institutions, leading to challenges in data recovery and integration. To address this gap, the ITINERIS Project (PNRR) has initiated Work Package 8.9, which focuses on developing the ISOTOPE Virtual Research Environment (VRE). A VRE can be described as an online environment offering remote and shareable disk space (workspace), catalogues and several customized tools for data processing. This initiative represents a pioneering step toward establishing Italy's first comprehensive national VRE service, encompassing a national database on stable isotopes. The Isotope VRE integrates tools for data analysis, interpretation, and modelling, enabling researchers and stakeholders to access coordinated information and advanced analytical tools. Some examples of data modelling are here reported: i) data plotting; ii) ternary diagrams; iii) mixing models. Initial results demonstrate the significant potential of the Isotope VRE in advancing our understanding of Earth system processes. Additional mathematical modelling approaches are under development, further enhancing the platform's capabilities. The Isotope VRE aims to provide the scientific community with a comprehensive virtual research environment for isotopic data sharing, analysis, and interpretation. This platform will empower researchers to investigate environmental processes with a suite of powerful tools, fostering new insights and applications in geochemistry and beyond.

The dataset represent the Supplementary material of thew manuscript entitled "Map of the top of the Variscan basement in some sectors of Italy" now under revision. The Supplementary material consist of 9 files: input data: dataset_CROP.csv deep_wells.csv domains.geojson thrusts_2.geojson INA_data_point.csv output data: INA_depth_1km.csv ONA_OA_ISA_AF_depth_5km.csv INA_contour.geojson ONA_OA_ISA_AF_contour.geojson

Italy has no record of Li production, even though it is well known for its outstanding Li mineral specimens from the Elba Island pegmatites. Because of the current geopolitical situation, the opportunity for a systematic appraisal of resources is evident. Most European Li production comes from deposits associated with Late Paleozoic magmatic rocks. In Italy, such rocks occur extensively in Sardinia and Calabria, but their potential for Li is unknown, and deserves a more systematic exploration. Also of potential interest are the Permo–Triassic spodumene pegmatites in the Austroalpine units of the Central Alps. The Tertiary pegmatites (Elba Island and Central Alps) contain Li minerals, but do not appear large enough to warrant bulk mining. However, we notice that Tertiary–Quaternary magmatic rocks of the Tuscan and Roman magmatic provinces have systematically higher Li contents than those recorded in normal arc igneous rocks worldwide. Specifically, Tuscan granites contain up to 350 μg/g Li, mostly hosted by biotite (up to 4000 μg/g Li); the Capo Bianco aplite (Elba Island) contains up to 1000 μg/g. There are other small Li occurrences associated with Mn deposits and metabauxites, and there is a hypothetical potential for sediment-hosted deposits in the post-orogenic Lower Permian Alpine basins. However, the most promising potential seems to be associated with subsurface fluids. High-enthalpy fluids in geothermal fields may contain up to 480 mg/L Li. Lower-temperature thermal waters may also contain significant Li (>10 mg/L). Moreover, a visionary, but not impossible, perspective may consider a deep injection of water to interact with, and extract Li from, magmatic rocks.

This paper aims at sharing 3D geological models that were constructed at different scales in two Mexican geothermal areas as part of the European-Mexican GEMex project. The project was devoted to investigate superhot resources in Los Humeros and enhanced geothermal systems in Acoculco, both areas located in eastern Mexico. To build confidence in the resultant datasets and to potentially inform the development of models in similar contexts, the methodology is also described. The models integrate the main geological and geothermal features of the study areas and served as a framework for subsequent calculations and simulations. Preliminary models were based on data available at the beginning of the project, and were updated several times as new geological, geochemical, and geophysical field-data were obtained. The construction of the geomodels was performed in a collaborative and interdisciplinary way, using an existing software, and ultimately enabled a consensus interpretation and representation to be reached by the several disciplinary experts involved.

Italy has never been a lithium (Li) producer, and the potential for “hard rock” deposits is moderate at best. On the other hand, the increasing demand for Li-based rechargeable batteries fostered new interest in this metal, and prompted the quest for alternative resources. The extraction of Li from geothermal brines (“geothermal lithium”) is currently considered in several countries, including, in Europe, France, Germany, and UK (EGEC, 2020).Italy has vast geothermal resources, and there is a potential for “geothermal lithium” as well. A preliminary survey of literature data pointed out several occurrences of fluids with Li contents up to hundreds of mg/L. Among high-enthalpy fluids, we point out those of Cesano, Mofete, and Latera. At Cesano, geothermal fluids contain about 350 mg/L lithium (Calamai et al., 1976). Early studies conducted in the past century (Pauwels et al., 1990) suggested the feasibility of lithium recovery from these fluids. Even higher contents (480 mg/L) occur in the deep reservoir at Mofete (Guglielminetti, 1986), whereas fluids in the shallow and intermediate reservoir in the same field contain 28 to 56 mg/L. Geothermal fluids at Latera have somewhat lower contents (max 13.5 mg/L; Gianelli and Scandiffio, 1989). Several low-enthalpy thermal waters in Emilia-Romagna, Sardinia, Sicily and Tuscany also show significant (> 1 mg/L) Li contents (max 96 mg/L at Salsomaggiore; Boschetti et al., 2011). There are no published Li data for high-enthalpy fluids at Larderello; however, evidence of Li-rich fluids was found in fluid inclusions in hydrothermal minerals (Cathelineau et al., 1994). Moreover, the shallow (ca. 3.5 km) granitoid body underlying the field contains a Li-rich (about 1,000 ppm) biotite (A. Dini, unpublished data); it has been estimated that such rock may contain as much as 500 g Li per cubic meter.ReferencesBoschetti T., et al. - Aquat Geochem (2011) 17:71–108Calamai A., et al. - Proc. U.N. Symp. Development Use Geotherm. Energy, S. Francisco, USA (1976), 305-313Cathelineau M., et al. – Geochim. Cosmochim. Acta (1994) 58: 1083-1099EGEC (European Geothermal Council). https://www.egec.org/time-to-invest-in-clean-geothermal-lithium-made-in-europe/. Accessed December 2, 2020.Gianelli G., Scandiffio G. - Geothermics (1989) 18: 447-463Guglielminetti M. - Geothermics (1986) 15: 781-790Pauwels H., et al. - Proc. 12th New Zealand Geothermal Workshop (1990), 117-123

Data gathered from two geothermal exploration wells in the Acoculco caldera, within the Trans-Mexican Volcanic Belt, indicated that temperature is high enough for economic utilization, but permeability is insufficient. Hence, heat exploitation at this location may only be possible by Enhanced Geothermal System (EGS) technologies. To evaluate the potential for EGS development, a wide range of exploration work has been carried out in the framework of the international research project GEMex. In this manuscript, we present best estimates of the in-situ stress field conditions at the site – an important, yet highly uncertain, parameter for stimulation planning. The study is based on geological data, drilling parameters, geophysical logging, laboratory measurements on collected rock samples, and statistical analyses. The in-situ stress regime of the Acoculco geothermal area can be described as transtensional with a maximum horizontal stress striking in the NE-SW direction, a pore pressure gradient of 8.73 MPa·km-1, a minimum horizontal stress gradient of 22.8 ± 3.3 MPa·km-1, a vertical stress gradient of 24.3 ± 1.5 MPa·km-1, and a maximum horizontal stress gradient of 42.9 ± 28.5 MPa·km-1. Based on the predicted stress tensor, we estimate the maximum pressure required to enhance the rock permeability and discuss the potential EGS development options for the Acoculco geothermal area.

Construction of this dataset is described in the peer-reviewed publication: Calcagno, P., Trumpy, E., Gutiérrez-Negrín, L.C., Liotta, D. A collection of 3D geomodels of the Los Humeros and Acoculco geothermal systems (Mexico). Sci Data 9, 280 (2022). https://doi.org/10.1038/s41597-022-01327-0 The geomodel is available in the form of the following files and formats: Metadata sheet description pdf format GeoModeller project format PDF3D format TSurf format VTK format

Construction of this dataset is described in the peer-reviewed publication: Calcagno, P., Trumpy, E., Gutiérrez-Negrín, L.C., Liotta, D. A collection of 3D geomodels of the Los Humeros and Acoculco geothermal systems (Mexico). Sci Data 9, 280 (2022). https://doi.org/10.1038/s41597-022-01327-0 The geomodel is available in the form of the following files and formats: Metadata sheet description pdf format GeoModeller project format PDF3D format TSurf format VTK format

Construction of this dataset is described in the peer-reviewed publication: Calcagno, P., Trumpy, E., Gutiérrez-Negrín, L.C., Liotta, D. A collection of 3D geomodels of the Los Humeros and Acoculco geothermal systems (Mexico). Sci Data 9, 280 (2022). https://doi.org/10.1038/s41597-022-01327-0 The geomodel is available in the form of the following files and formats: Metadata sheet description pdf format GeoModeller project format PDF3D format TSurf format VTK format

This paper presents a workflow for resource characterization and assessment of exploration geothermal fields with minimum data. Our approach utilizes stochastic methods to estimate the temperature distribution at potential target depths by focusing on the impact of uncertain input parameters such as thermal conductivity and porosity. We first perform stochastic forward simulations to determine the initial steady-state thermal field and subsequently quantify the uncertainty via a Monte Carlo approach known as Sequential Gaussian Simulation (SGSim). Next, we analyze the in-field likelihood of success for Enhanced Geothermal Systems by simulating hypothetical energy production scenarios based on existing geothermal installations. This approach is applied to the case study of a Hot Dry Rock geothermal field with two exploration wells, located in Acoculco, Mexico. Data scarcity in this field necessitates the use of stochastic methods for plausible prediction of reservoir temperature used to determine the accessible thermal power. Once reliable temperature estimates are obtained at potential target depths, we simulate production scenarios by assuming a prior successful stimulation process in the existing wells. In addition to providing preliminary estimates of thermal power for different injection/production rates, stimulated volumes and created permeability, we present the long-term impact of production on the temperature and pressure fields.

A large and increasing number of countries use geothermal energy as power source for domestic and industrial applications. Geothermal power plants produce energy out of this natural and renewable source in a sustainable way and contribute to reduce global warming. However, power plants effectiveness depends on the suitability of an area to geothermal energy production, which is a complex and unknown combination of many environmental factors. Nowadays, geothermal suitability assessments require invasive inspections, high costs, and legal permissions. Thus, having a global suitability map of geothermal sites as reference would be useful prior knowledge during assessments, and would help saving time and money. In this paper, the first suitability map of potential geothermal sites at global scale is presented. The map is the result of the application of data collection and preparation processes, and a Maximum Entropy model, to geospatial data potentially correlated with geothermal site suitability and geothermal plants operation. The reliability of our map is assessed against currently active and planned geothermal power plants. Our approach follows the Open Science paradigm that guarantees results reproduction and transparency, and allows stakeholders to reuse the produced standardised data, services, and Web interfaces in other experiments or to generate new maps at regional scale. Overall, our results can help scientists, industry operators, and policy makers in geothermal sites assessments. Also, our approach supports communication with citizens whose territories are involved in probing and assessments, in order to transparently inform them about the reasons driving the selection of their territory and the potential future benefits.

The objective of this work is to define best practices in the management of geothermal exploration data. This study builds on a questionnaire to survey the geothermal data management practices in mature geothermal markets. The inquiry targeted public Regulatory entities with overview of geothermal resources as well as public and private developers. Topics covered in the questionnaire range from the country status to the database set up. The questionnaire focused on the specifications, usage and investments required for installing/maintaining information systems capable of managing exploration data. In addition, information on the different regulatory frameworks and company policies for managing/sharing exploration data has been gathered to identify the requirements imposed on the design of information systems. The responses were analyzed to identify commonalities in data management practices. They reveal that installing an Information System (IS) is the best practice to systematically and securely manage exploration data. They also provide recommendations with respect to the regulatory framework, data types, data collection methodologies, data storage, data quality control, data accessibility and dissemination, IS architecture, financial investments and human resources required to develop a state-of-the art IS. These results will guide the design of future technical assistance programs for beneficiaries of World Bank support to geothermal exploration activities and it is our belief that they will be beneficial for the geothermal sector at large.

Based on a joint analysis of geothermal indicators (e.g. temperature map at different depth, surface heat flux) and practical features (e.g. restricted areas, existing research lease), two promising areas in southern Tuscany were identified to perform a more detailed geothermal resource characterization. An area is located on the north-east of the Larderello-Travale geothermal field, and the other one is located on the west of the Mt. Amiata geothermal field. A quantitative geothermal resources assessment was performed in the aforementioned areas of Tuscany by solving numerical thermo-fluid dynamic models and by computing the geothermal potential using the ‘ThermoGIS’ software, as further developed for the Italian case (Trumpy et al., 2016). First of all, geological and geophysical data required for geological and thermo-fluid dynamic modelling were collected and organised. The geological data were used to build a 3D geological model of the two areas of interest suitable for numerical simulations. Static temperature data gathered from the Italian National Geothermal Database together with site-specific heat flow measurements were used to calibrate the simulated steady state temperature distribution. The geothermal potential computed by integrating geological, thermal and petro-physical information implementing the volume method used in ThermoGIS provided estimates of the heat in place and the geothermal technical potential maps. The resulting technical potential in the area close to Larderello –Travale is 330 MWe and in the Mt. Amiata sector is 50MWe. References Trumpy E., Botteghi S., Caiozzi F., Donato A., Gola G., Montanari D., Pluymaekers M., Santilano A., Van Wees, J.D., Manzella A. Geothermal potential assessment for a low carbon strategy: a new systematic approach applied in southern Italy. Energy 103, 167-181, 2016.

A revised surface heat flow map of a sector of the Northern Apennines is presented, constrained by recently available thermal and petrophysical logs from 174 wells drilled for geothermal and hydrocarbon exploration purposes. The borehole temperatures have been corrected for drilling, inclination, and palaeoclimate effects. The corrected temperature data, combined with petrophysical parameters for each individual formation, have been used to derive shallow geotherms (down to a maximum depth of 8 km), which have yielded site-specific heat flow values. These values, once corrected for palaeoclimatic topographic and erosion/sedimentation effects, have been contoured by a kriging procedure to obtain the heat flow map. The map shows a clear distinction between a western zone (the Tyrrhenian Domain) of high heat flow (> 150 mW m(-2)), with closely spaced heat flow isolines, and an eastern zone (the Adriatic Domain) of relatively low (< 70 mW m(-2)), spatially uniform heat flow. The boundary between the two zones is roughly parallel to the axis of the Apennines. Five crustal geotherms (extending to the Moho) and the corresponding rheological profiles confirm that the 70 mW m(-2) isoline corresponds to a major tectonic boundary, across which the thermal, structural, and seismic properties of the lithosphere go through a significant change.