In recent years, deep-seated hydrocarbon reservoirs have gradually become the focus of exploration and development. The distribution of deep-seated oil reservoirs in the southern part of the Panyu 4 depression in the Pearl River Mouth Basin shows the characteristics of more in the north and less in the south, and uneven in the east and west. The unclear causes of oil differentiation have constrained its exploration. This paper uses a combination of logging, seismic, and physical property data to analyze the reasons for oil enrichment differences from the perspectives of source-reservoir matching, dominant migration channels, and fault activity, and establishes an oil accumulation model.

Research findings indicate that: (1) Based on the matching relationship between hydrocarbon source rocks and reservoirs, the area can be divided three types of well areas: "near-source poor in sand", "near-source rich in sand", and "far-source rich in sand". The northern sand bodies close to the hydrocarbon source rocks and have a large scale, so the oil enrichment degree is relatively high. (2) The fault structure ridges are the preferred channels for lateral oil migration. The oil is more enriched in the well areas near the structure ridge, leading to differences in oil reservoir between adjacent well areas in the east-west direction. (3) The strength of fault activity controls the stratum of oil enrichment in different well areas. In the northern area, the fault activity is strong, and oil is distributed in multiple stratum. In the southern area, the fault activity is weak, and the oil is transported over long distances through the oil source fracture and the sand body of the Wenchang Formation to the high structural parts in the south, where they are trapped in the Wenchang Formation. (4) Based on the aforementioned research, two types of oil accumulation models were established: the "proximal fault multi-layer accumulation model" near the source and the "long-distance stepwise migration and accumulation model" far from the source, along the dominant migration channels. This study has significant guiding implications for the further exploration and development of the Panyu 4 depression oil reservoir.

Key words: Differential enrichment of oil; Source-reservoir matching; Dominant migration channel; Fault activity; Oil accumulation model.

How to cite: Wang, Q., Liu, H., Peng, G., and Long, Z.: The mechanism of differential enrichment of deep oil reservoirs in the southern part of the Panyu 4 depression in the Pearl River Mouth Basin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3371, https://doi.org/10.5194/egusphere-egu25-3371, 2025.

What is more frightening than an unexpected earthquake in the middle of the night for people and for buildings and especially heritage buildings whose response to the earthquake is unknown.
The country of Morocco, and more precisely the region of Al Haouz, more precisely the city of Marrakech named capital of culture of the Islamic world for the year 2024, by the Islamic World Educational, Scientific and Cultural Organization (ICESCO), experienced a serious earthquake of magnetitude M = 6.9 on September 8, 2023 at 22:11:2.2 UTC (23:11 Local), the most serious earthquake in the history of the country according to seismic stations.
The Koutoubia Mosque built in the 12th century was one monument among others that suffered this tremor.
In this article we will describe the location, the construction technique and the materials used in this monument and we will also go through in a non-exhaustive manner the damage caused by this earthquake on the Koutoubia Mosque whose architecture is part of Almohad art.

How to cite: Belhaj, S., Baba, K., Belhaj, O. E., and Nounah, A.: The built material architectural cultural heritage tested by the Al Haouz earthquake: Case of the Koutoubia Mosque in the city of Marrakech, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13397, https://doi.org/10.5194/egusphere-egu25-13397, 2025.

The use of earth in the building industry offers the opportunity to reuse soil whiles meeting the challenges of circular economy through soil reuse and low embodied energy. However, the lack of standardized criteria for soil classification, suitability and a comprehensive understanding of the interactions between soil properties and construction techniques remain a significant barrier to widespread adoption. This study aims to propose criteria for evaluating and optimizing soil classification and suitability in earthen construction through experimental analyses. For this, the study will use three different soils, sampled from three different regions in France. Straw- fibred and non-fibred cylindrical specimen will be prepared in laboratory using the cob and adobe techniques. The prepared specimens will be dried at 40 °C and conditioned in a climatic chamber at 20 °C and 50 % relative humidity. The variation in dry densities, and Unconfined Compressive Strength (UCS) of the cob and adobe specimens will be observed. The impact of soil properties and implementation parameters such as water content, mineralogical composition (calcite and dolomite content) on these variations will be analyzed. To underline the contribution of these parameters, a principal component analysis (PCA) will be conducted on all the results to identify the most dominant factors affecting mainly the dry densities and soil strength. Future work will study the microstructure evolution in the specimens using the Brunauer – Emmett – Teller (BET) and the Mercury Intrusion Porosimetry (MIP) tests. The mechanical behaviour and microstructure evolution will be combined into developing new criteria for soil suitability considering the implementation process parameters and soil properties for earth construction.

How to cite: Ansaa-Asare, R. J., Das, G., Hamard, E., Razakamanantsoa, A., Duc, M., Cazacliu, B., and Verron, L.: An approach to develop suitable criteria for cob and adobe techniques, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21192, https://doi.org/10.5194/egusphere-egu25-21192, 2025.

The success of Carbon Capture, Utilization, and Storage (CCUS) projects heavily depends on understanding subsurface fluid flow behaviour particularly through fracture networks. Fractures play a dual role in such operations: they can enhance reservoir injectivity and storage capacity by providing pathways for CO₂ injection, but they also pose risks by potentially compromising caprock integrity, increasing the risk of structural storage failure thereby enabling CO₂ leakage. Accurate fracture detection and characterization is essential for optimizing injection strategies, ensuring effective containment, and mitigating environmental risks. Fractures influence critical processes such as trapping mechanisms and pressure distribution within the reservoir. Furthermore, understanding their orientation and density is vital for designing safe and efficient CO₂ injection operations. These factors highlight the importance of robust, non-bias, automated, and scalable fracture detection methods. Traditional fracture identification methods rely heavily on manual interpretation, which is time-intensive, subjective, and challenging to scale for large fields with several wells. This study proposes a scalable automated methodology employing advanced deep-learning techniques to detect fractures from borehole imaging tools such as FMI, CMI, and ThruBit logs. The proposed approach uses detection transformers which eliminates the need for manual mask creation and post-processing steps by adopting an end-to-end framework, which not only identifies the presence of fractures but also estimates their orientation and density. Custom evaluation metrics were developed to measure the model's performance (in comparison with expert’s fracture analysis) in handling diverse geological and well conditions, including vertical and horizontal well orientations. The automated workflow facilitates speedy assessment of fracture networks which in turn can offer speedy actionable insights for CO₂ injection optimization, caprock stability assessment, and risk management. The model demonstrated an interpretation speed of less than one minute per 2 meters, with an ~80% F1 score (6 cm depth error margin), ~91% accuracy in dip picking (3° error margin), and ~93% accuracy in dip estimation (15° dip margin). By utilizing the proposed automated fracture detection model based on transformers, CCUS project planning and designing can be accelerated. Furthermore, integrating MLOps into the workflow ensures the scalability, maintainability, and adaptability of these models for practical deployment. While this methodology is tailored to CCUS, its versatility extends to a much wider range of applications, including geothermal energy, mining, and other subsurface characterization domains.

How to cite: Nasim, M. Q., Maiti, T., Mosavat, N., Grech, P. V., Singh, T., and Roy, P. N. S.: Automated end-to-end fracture identification, classification, localization, and parameter estimation for enabling rapid risk management and CO₂ storage optimization in CCUS applications, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-627, https://doi.org/10.5194/egusphere-egu25-627, 2025.

The development of renewable energies and the sustainable utilisation of geo-resources is evident in the increasing interest in mine water utilisation. In the densely populated regions of former coal mining areas, flooded mine structures present a promising opportunity for seasonal heat storage called mine thermal energy storage MTES. In addition to the general risks associated with post-mining utilisation, it is essential to assess the potential hazards posed by contaminants that may be remobilised through this geotechnology. Hard coal naturally contains contaminants such as polycyclic aromatic hydrocarbons (PAHs) and NSO-heterocycles, which have been detected in mine water. The utilisation of coal mines as thermal energy storage facilities leads to significant heating of the mine water (up to 80°C), which can enhance the solubility and mobilisation of contaminants into the water. However, to date, no comprehensive understanding exists regarding the mobilisation potential of these contaminants from coal mines at varying temperatures.

In this contribution, we present initial systematic flow-through experiments using columns filled with different coal types at various temperatures demonstrating that contaminant mobilisation, after an initial first flush, is primarily dominated by diffusion processes at the phase interface. Differences in the mobilisation of PAHs between the various coal types and at various temperatures are discussed.

Using numerical simulations, we demonstrate that the compound concentrations grow exponentially over the runtime of the MTES system due to the growing mass of coal being thermally stimulated. High temperature storage can lead to a short production time until the regulatory limit for PAH is reached. Without regulatory action an MTES in coal mines might not be economically.  We highlight that depending on mine-specific factors countermeasures need to be installed to contain the potential risk to the economic feasibility of such a storage system.  A reduction of the pollutants trough remediation techniques might be possible to enhance the lifetime of the MTES system, if natural attenuation through micro-biological activity is not sufficient.

How to cite: Blaes, L., Licha, T., and Heinze, T.: Organic compounds pose a risk for thermal storage in abandoned coal mines, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11945, https://doi.org/10.5194/egusphere-egu25-11945, 2025.

The Himalayan alpine treeline possesses a unique identity and plays a vital role in the ecosystem. This study explores the relationship between soil quality and the distribution, diversity, and regeneration patterns of tree species in the alpine treeline regions of Uttarakhand Himalaya. The research focuses on five different treeline sites in Uttarakhand: Dayara Bugyal, Tungnath, Valley of Flowers, Ali-Bedni Bugyal, and Khaliya Top. Tree diversity and regeneration sampling in the treeline region were conducted by laying out 0.01 hectares quadrats, which were selected using the belt transect method along the treeline and soil samples were collected from each quadrate at 0-15 and 15-30 cm soil depths. The Rhododendron campanulatum, Quercus semecarpifolia, Abies spectabilis and Betula utilis are predominant in the treeline region of Uttarakhand Himalaya. Analysis of tree regeneration indicates generally poor regeneration for most species, with specific site variations. The additive Soil Quality Index (SQI) ranged from 2.30 to 2.84, 2.35 to 2.84, and 2.32 to 2.84 at soil depths of 0–15 cm, 15–30 cm, and 0–30 cm, respectively. Similarly, the weighted SQI showed a comparable trend, with Ali-Bedni Bugyal recording the highest values (0.95–0.96 across all depths). The reported SQI values exhibited a positive correlation with soil physicochemical properties and a negative correlation with vegetation density at the seedling, sapling, and tree stages. The site-specific variations in tree species distribution, diversity, and soil quality reflect distinct ecological dynamics and species interactions, while the poor regeneration status of most tree species highlights the need for targeted conservation strategies.

How to cite: Kumar, S., Sati, S. P., and Khanduri, V. P.: Tree density, distribution and regeneration status in relation to soil quality at different alpine treeline regions of North-west Himalaya, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1094, https://doi.org/10.5194/egusphere-egu25-1094, 2025.

Taiwan's Tatun Volcanic Group (TVG) is an active tectonic zone that moved from tectonic compression zones to crustal expansion. It is a graben, or region of crustal thinning structure, that is favorable to crustal magmatic intrusion. This geologic context supplies heat for the formation of geothermal and volcanic systems. In addition, TVG is a suitable location for geothermal exploration because of the numerous surface thermal characteristics associated with young volcanic rocks. By computing the geothermal radiative heat loss based on the land surface temperature (LST) obtained from thermal sensors on Earth-observing satellites, we can assess the geothermal resource reservoir of TVG. Firstly, the Stefan-Boltzmann law from the LSTs is used to derive the radiative heat flow (RHF). Second, the sum of the heat flux pixel values over the selected geothermal area is used to estimate the overall radiative heat loss (RHL). The background radiative heat loss is then computed, and by deducting the background radiative heat loss from the total radiative heat loss, geothermal (i.e., net) radiative heat loss is determined. The above process determines trends in geothermal radiative heat loss over time. The average value of the four-decade (1984 - 2024) trend of geothermal radiative heat loss at TVG is 211 MW, with an annual rate of increase of 1 MW (MegaWatt) each year. The mean value of heat loss estimation follows the same sequence as the traditional geochemical method used in earlier research. On the other hand, this study's annual growing rate estimation of TVG is noted for the first time. This study shows the advantages and benefits of employing long-term remote sensing datasets in geothermal and volcanic investigations. It is the first attempt to assess TVG's geothermal potential using satellite thermal observations. This application of remote sensing methods in TVG's geothermal investigation shows encouraging outcomes and can be applied to other geothermal systems across the globe.

How to cite: Chan, H.-P. and Chan, Y.-C.: Tatun Volcanic Group geothermal assessment: estimated radiative heat flux and heat loss from satellite thermal time-series datasets, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3869, https://doi.org/10.5194/egusphere-egu25-3869, 2025.

Soil diffuse CO₂ efflux and soil radon (²²²Rn) and thoron (²²⁰Rn) gases activities measurements may be useful geochemical indicators of subsurface volcano-hydrothermal processes in geographical areas where visible gas emissions are nearly absent. Both radon (²²²Rn) and thoron (²²⁰Rn) are radioactive isotopes derived from the natural decay of uranium (²³⁸U) and thorium (²³²Th) respectively, present in the mineralogical composition of rocks. The main difference between these two isotopes is their half-life time. While ²²²Rn presents a half-life of 3.8 days, ²²⁰Rn has a shorter half-life of 55 seconds. Therefore, high ²²²Rn surface activity is considered to be associated with deep magmatic sources of gas while high ²²⁰Rn activity is associated with shallow soil gas sources.

A total of 968 sampling sites in an area of 25 Km² have been considered as part of a detailed surface geochemical study at the central-western part of La Palma and southwards from the 2021 volcanic eruption lava flow of Tajogaite Volcano. Both diffuse soil CO₂ efflux and radon and thoron activities discrete measurements were executed during field surveys between 2023 and 2024.

The diffuse CO₂ efflux measurements were determined, based on the non-stationary static accumulation chamber technique, using CO₂ sensors contained in a portable flux-meter, and the radon and thoron activities were evaluated using a SARAD radon monitor connected to a stainless steel probe inserted at 40 cm depth. Soil gas samples were also collected and analyzed in the laboratory to obtain the chemical and carbon isotopic composition profile.

Data analysis and treatment showed CO₂ efflux values up to 106 g*m^-2/day, ²²²Rn values up to 27000 Bq/m³ and ²²²Rn/²²⁰Rn ratio up to a maximum of 49. Both ²²²Rn versus ²²²Rn/²²⁰Rn ratio plotted together enabled to identify areas with a higher contribution of deeper sourced gas,which might indicate potential zones of interest of geothermal resources.

Furthermore, spatial distribution maps of these variables showed that the main CO₂ and radon gases anomalies are located along the coastline of the studied area, coincident with anomalous magmatic-hydrothermal origin CO₂ diffuse degassing areas. The magmatic-hydrothermal CO₂ might have acted as a carrier gas controlling the migration and transport of the radon trace gas towards the surface.

In conclusion, surface geochemical surveys might be useful for geothermal resources exploration studies, providing a reasonable definition of potential geothermal system boundaries and permitting an efficient and cost-effective posterior subsurface exploration phase.

How to cite: Gironés, A., Pérez, N., Padrón, E., Melián, G. V., Asensio-Ramos, M., Hernández, P. A., Padilla, G. D., Di Nardo, D., Martín, A., Ramos, C., Taño, D., and Trujillo, L.: Detailed surface geothermal exploration by means of diffuse CO2 efflux, radon measurements and radon/thoron ratio in Jedey, La Palma, Canary Islands, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15478, https://doi.org/10.5194/egusphere-egu25-15478, 2025.

Geothermal energy, driven largely by the push towards achieving net-zero emissions, has garnered increasing interest in the past decades for electricity generation. Geothermal-related activities, as any other activity for energy projects that utilise the subsurface, could induce subtle deformations on the near-surface. Tiltmeters is a technology capable to detect submillimetre ground deformations but can be significantly affected by ambient temperature variations. This effect can mask potential minute deformation signals. The effect of ambient temperature variations on tiltmeter recordings still lacks systematic understanding due to the absence of precise monitoring data and appropriate interpretation guidelines. In this study we analysed continuous tiltmeter recordings for a full year period and quantified the close correlation between the ambient temperature and ground displacement in both east-west (EW) and north-south (NS) directions. This close relationship has also been suggested by their wavelet coherence (WTC) results with only small time-lag observed. Overall, appropriate recognition of temperature-related ground motions can benefit the understanding of shallow crust and promote the establishment of baseline for future geothermal-related practices.

How to cite: Qiu, C. and Pytharouli, S.: Quantification of the Impact of temperature variation on tiltmeter recordings for ground deformation monitoring, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20467, https://doi.org/10.5194/egusphere-egu25-20467, 2025.

To safely store CO₂, it is necessary to accurately predict the behaviors and trapping evolution of CO₂ in saline aquifers. However, due to the heterogeneity of actual saline aquifers, the evolution of CO₂ plume and accompanying trapping are still unclear during and after injection. Although prior studies have highlighted the impact of capillary entry pressure heterogeneity on CO₂ plume and trapping, the role and influence of CO₂-induced geochemical reactions are still not fully understood. Therefore, the main objectives of this work are to study the evolution of CO₂ plume and storage under heterogeneous capillary entry pressure and geochemical reactions. To illustrate the evolution, a comprehensive CO₂ migration and storage model under heterogeneous capillary entry pressure and geochemical reactions is done to study CO₂ behavior in detail. The results showed that heterogeneous capillary entry pressure in the saline aquifer can hinder the upward migration of CO₂, causing it to redirect and increase its lateral volume. The geochemical reactions can reduce porosity by 10^-4 and permeability by 1 mD within 100 years and hinder CO₂ migration in all directions. The capillary entry pressure magnitude, its heterogeneity, and lateral correlation length are the main parameters affecting the evolution of CO₂ storage. Their increase can greatly limit CO₂ vertical migration rates and decrease dissolution and mineral trapping amount but may double local capillary trapping amount. In contrast, the increase in temperature and the ratio of vertical/horizontal permeability favors CO₂ vertical migration, dissolution, and mineral trapping amount. Therefore, to ensure the long-term safety of CO₂ storage, it is necessary to select a suitable heterogeneous reservoir.

How to cite: Cui, G., Hu, Z., Chen, X., Liu, Z., and Lian, Y.: Influence of capillary force heterogeneity and geochemical raction on CO2 flow and trapping, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4956, https://doi.org/10.5194/egusphere-egu25-4956, 2025.

With the increasing urgency of global climate change and rising energy demand, carbon dioxide (CO2) geological storage has garnered significant attention as an effective method for mitigating greenhouse gas emissions. In the CO2 geological storage process, understanding the behavior of formation fluids is crucial to ensuring both the safety and long-term stability of storage. However, in actual storage operations, industrial CO2 emissions are rarely pure and typically contain a variety of impurity gases. As a result, CO2 must undergo purification prior to injection, a process that is not only time-consuming but also adds substantial costs. When considering the entire carbon capture and storage (CCS) chain, including capture, transportation, and purification, the total cost of operating current and future CCS projects can reach nearly one billion dollars. According to recent literature, the transportation and storage costs for CO2 can be as high as 45 USD per ton. In China, where cost sensitivity is especially high, these elevated expenses could significantly hinder the implementation of CO2 storage projects. Industrial CO2 emissions often contain not only CO2 but also other gases such as N2, O2, H2S, H2, and SO2. Direct injection of these gas mixtures into subsurface storage sites has the potential to reduce the overall cost of a CO2 geological storage project. However, the effects of impurity gases on storage mechanisms and long-term safety remain insufficiently understood and require further investigation. This study explores the response mechanisms of formation fluids in the context of non-pure CO2 geological storage, focusing on the influence of water-rock reactions, water-rock-gas interactions, permeability, solubility, and changes in the ionic composition of formation waters.

Keywords: water-rock reactions; impure CO₂; permeability; solubility; formation water ionic changes

How to cite: liu, S. and Peng, B.: Study on the response of formation fluid during geological storage of impure carbon dioxide, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21409, https://doi.org/10.5194/egusphere-egu25-21409, 2025.

In the project focused on CO₂-enhanced coalbed methane exploitation and geological storage, the seam network structure of coal seams serves as a conduit for gas migration, diffusion, displacement, and storage. The mechanical properties of these coal seams are intrinsically linked to the propagation and evolution of cracks. Prolonged exposure of coal seams to CO₂ adsorption environments inevitably alters their structure and mechanical properties. Consequently, experimental research has been conducted on the microstructure and mechanical properties of coal seams with potential for CO₂ geological storage in China. The results indicate that, under varying CO₂ adsorption pressures and durations: The relative contents of calcite, chlorite, and kaolinite in coal decrease, while the relative content of quartz increases significantly. Notably, the influence of supercritical CO₂ on mineral composition and relative content changes is the most pronounced. Long-term CO₂ adsorption accelerates mineral dissolution and ion exchange rates in coal, resulting in a rougher surface of coal mineral particles. Numerous secondary pores and fractures emerge and coalesce to form dissolution pits and grooves. Some mineral particle structures transition from intact to fragmented, severely weakening the skeleton particles and mineral bonding strength. Significant transformations occur in pores and fractures of different scales, with CO₂ adsorption causing a mutual transformation of mesopores and micropores in coal, albeit without altering the pore type. The uniaxial compressive strength, Brazilian splitting strength, and fracture toughness of coal exhibit a similar trend with increasing CO₂ pressure: an initial rapid decrease followed by a gradual, more gradual decrease. The mechanical strength/fracture toughness of coal samples with three different bedding types follows the order: Diverder type > Arrester type > Short transverse type. As CO₂ pressure increases, the destructive characteristics of coal transition from sudden instability to gradual instability, and then back to sudden instability. Under CO₂ adsorption, coal fracture trajectories can be classified into three types and 12 subtypes: single destruction, multi-source destruction, and fragmentation destruction trajectories. The interaction between CO₂ and coal alters the specific surface area, total pore volume, and uniformity of pore size distribution of coal, significantly impacting its composition. These microstructural changes underpin the macroscopic mechanical properties of coal, which in turn affect its mechanical properties and failure characteristics. The research findings have significant implications for evaluating the efficiency and stability of CO₂-enhanced coalbed methane mining and CO₂ geological storage.

How to cite: Feng, G., Xie, H., Wu, F., Xiao, M., Sun, Z., Liu, H., Jin, P., Wang, G., Meng, T., and Hu, Y.: Experimental study on the influence of CO2 adsorption on the mechanical properties of anisotropic coal, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21370, https://doi.org/10.5194/egusphere-egu25-21370, 2025.

Rare earth elements (REE) have become indispensable in a wide range of modern technologies, yet their potential environmental impacts in gold mining regions are poorly understood. In this study, we collected soil samples from various locations within gold mining areas and analysed their REE contents using Neutron Activation Analysis (NAA), a precise and non-destructive method. To evaluate contamination levels and potential ecological harm, the enrichment factor (EF), geoaccumulation index (Igeo), and ecological risk index were applied.

Results revealed varying degrees of REE enrichment across sampling sites, with elevated EF values ranging from 0.20 to 2.70 and PLI values between 0.27 and 1.16 indicating no enrichment. Specifically, Eu and Tb showed the slight enrichment factors, might indicating an anthropogenic influence. The ecological risk index further indicated that 12.5% of the sampling sites might pose moderate ecological risks.

Overall, these findings underscore the importance of systematic REE monitoring and risk assessment in gold mining regions. Integrating REE analyses into environmental management strategies can help mitigate potential ecological impacts, ensure sustainable resource utilisation, and preserve environmental quality in these mineral-rich landscapes.

How to cite: Ahmed, M. E., Abbo, M. A., and Bounouira, H.: Integrating Neutron Activation Analysis and Multi-Index Assessments to Evaluate Rare Earth Elements in Sudanese Gold Mining Areas, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2493, https://doi.org/10.5194/egusphere-egu25-2493, 2025.

The growing demand for copper, driven by its critical role in green energy technologies such as electric vehicles and renewable energy systems, underscores the need to identify new copper resources. The Aravalli-Delhi Mobile Belt (ADMB), a geologically complex terrain spanning Rajasthan, Haryana, Gujarat, and Delhi, represents significant potential for copper mineralization within its Archaean to Neoproterozoic sequences. In this study, we developed a high-resolution copper prospectivity map for the ADMB by leveraging advanced machine learning techniques and integrating diverse geoscientific datasets. Our methodology incorporated geological features (e.g., proximity to folds, faults, and lineaments), geophysical data (gravity and magnetic anomalies), and remote sensing inputs (SRTM and LANDSAT imagery). Comprehensive processing of potential field data included upward continuation to multiple heights (500 m, 1000 m, 2000 m, 5000 m, 7500 m, 10,000 m, 15,000 m, 25,000 m, and 40,000 m), followed by the computation of first- and second-order directional derivatives, resulting in a total of 154 predictive features. Known copper deposit locations (56 in total) across the ADMB were used as training points, with feature sampling creating the dataset for machine learning model training. We addressed the challenge of class imbalance posed by the limited number of known deposits, by employing synthetic data generation techniques, including Variational Autoencoder (VAE) and Synthetic Minority Oversampling Technique with Generative Adversarial Networks (SMOTE-GAN). Comparative analysis showed that SMOTE-GAN produced more realistic synthetic samples, significantly improving model performance. The enriched datasets were used to train supervised learning models, including Explainable Boosting Machine and Random Forest, optimized within a Positive-Unlabeled (PU) Bagging framework to classify unlabeled regions. Our trained model achieved a predictive accuracy of 95.75% on an unseen dataset. The resulting copper prospectivity map effectively delineates high-probability zones, with nearly all known deposits falling within regions predicted to have probabilities >0.7. Our maps highlight regions of high prospectivity for copper resources that currently lack known deposits, suggesting potential new exploration targets.This demonstrates the robustness of our integrated data approach and machine learning models in identifying unexplored copper-rich areas within the ADMB. Our study highlights the importance of integrating geoscientific data with synthetic data generation to address data scarcity in mineral exploration. The demonstrated scalability of this framework provides a robust solution for prospectivity mapping in other similar Archaean to Neoproterozoic terrains worldwide.

How to cite: Kumar, M., Singh, S. P., Singh, U., Sarkar, S., Goyal, T., Sukhbir, S., and Shirmard, H.: Advanced Copper Prospectivity Mapping in Northwestern India through Machine Learning and Multisource Data Integration, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5044, https://doi.org/10.5194/egusphere-egu25-5044, 2025.

Metallic deposits such as W-Sn, Cu-Au, rare earth deposits, thus serving as a “giant granary” of metal mineral resources in China(Lü  et al.,2021). There are five large-scale metallogenic belts only in the east of South China, namely the Middle-Lower Yangtze River Metallogenic Belt (MLYMB), Qingzhou-Hangzhou Metallogenic Belt (QHMB), Nanling Metallogenic Belt (NLMB), Wuyishan Metallogenic Belt (WYSMB), and Xiangxi-E’xi Metallogenic Belt (XEMB).

The source zones of the mineral systems in major metallogenic belts in South China are reflected by the vertical structures of the lithosphere in this area. In MLYMB, the mineral systems of the Fe and Cu deposits have multi-level source zones. The initial-level source zone is the enriched mantle, which is formed owing to the thinning of the lithosphere and deformation caused by the fluids in the asthenosphere. In QHMB, the source zone of Cu deposits such as the Dexing deposit is the mantle, while the source zone of W deposits on the margin of the Moho uplift such as Zhuxi and Dahutang deposits is the remelted crust. As for QHMB, the W and Sn mineral systems originate from the crustal magma. In WYSMB, the diagenism and mineralization are mainly related to the interactions between materials in the crust and the mantle. The crust-derived materials form the deposits mainly containing W and rare earths, and mantle-derived materials form polymetallic deposits such as Cu and Au. As for XEMB, it consists mostly of metal deposits of the type of strata-bound sedimentation with the crust as the source zone, such as Sb, Pb, Zn, and Mn deposits.

The pathways of the mineral systems of the major metallogenic belts in South China are deep faults and block or terrane boundaries determined by edge detection of gravity anomalies, as well as density contrast boundaries obtained with the 3D density model. The metallogenic pathways of Fe and Cu deposits in MLYMB mainly include the Yangtze River deep fault in NE trending and Tongling-Taizhou fault in SE trending and its secondary faults. The eastern segment of QHMB is mainly controlled by the faults in northeast Jiangxi, the southern segment of QHMB and the NLMB are mainly under the control of the boundary faults of F1, and WYSMB is related to Zhenghe-Dapu fault and Heyuan-Shaowu fault.

 A 3D density and susceptibility model was obtained by 3D gravity and magnetic inversion. The distribution of different types of deposits was qualitatively reflected by different combination of density and susceptibility model, revealing the distribution of termination sites of different mineral systems in South China.Mineral systems in this area, providing indications for future ore-prospecting exploration in South China.

How to cite: Yan, J., Zhou, Q., Chen, C., and Tang, H.: The controlling factors of major metallogenic systems in south china based on gravity and magnetic analysis, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10108, https://doi.org/10.5194/egusphere-egu25-10108, 2025.

This study investigates the potential for mineral carbonation of carbon dioxide (CO₂) in plutonic basic rocks through a series of laboratory experiments conducted in two stages, under pressure (8 MPa) and temperature conditions (313.15 K) akin to those near a CO₂ injection well. Stage-I facilitated dissolution with crushed rock exposed to CO2 supersaturated seawater (0.6 M), while Stage-II promoted carbonation through cubic rock specimens in contact with CO₂ subsaturated seawater (0.1 M). A multi-analytical approach was employed to track the mineralogical and geochemical evolution of the rock and seawater. Brine analyses shows significant increases in iron, magnesium, and calcium ions, with reductions in silicon and aluminum levels. The solid phase showed minimal geochemical and mineralogical changes. Nevertheless, new mineral phases like halite and dolomite were detected by X-ray diffraction with a grazing geometry. In fact, although not detected on a bulk analysis, on the surface of specimens, and after the 120 days experiment, carbonate phases were detected. The geochemical model developed in the CrunchFlow code successfully replicated these observations and projected chemical behavior over longer periods. The findings suggest a promising potential for mineral carbonation in plutonic basic formations, though further studies are needed to scale the laboratory results to field applications.

The work is funded by H2020 – PilotSTRATEGY and national funds through FCT – Fundação para a Ciência e Tecnologia, I.P., in the framework of the UIDB/04449/2020 and UIDP/04449/2020 – Laboratório HERCULES; UIDB/04683 and UIDP/04683 – Instituto de Ciências da Terra program.

How to cite: Moita, P., Berrezueta, E., Pedro, J., Mirão, J., Beltrame, M., and Carneiro, J.: Geochemical evolution of cumulate-gabbro Interaction with Seawater and Supercritical CO2 for Enhanced Mineral Carbonation. A study case., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17270, https://doi.org/10.5194/egusphere-egu25-17270, 2025.

The reduction of atmospheric CO2 through its safe geological storage, as CCUS techniques is one of the goals to achieve the 2050 commitment. Within the scope of the PILOTSTRATEGY project, two sedimentary sequences Triassic (on-shore) and Cretaceous (offshore) were object of a detailed study in order to evaluate their potential as CO2 storage complexes in the Lusitanian basin (west Portuguese margin).

A multi-disciplinary, multi-analytical approach was applied to the potential reservoirs and caprock samples to their characterization. The obtained results (XRD, TGA, petrography) reflect the predominance of siliciclastic composition of the reservoirs (mainly quartz and K-feldspar) whereas the caprock exhibit a carbonate (mainly calcite) (Cretaceous) or gypsum (Triassic) composition.

Several batch reaction experiments were carried out at Edinburgh University (UEDIN). Samples from the Cretaceous storage complex reacted with a NaCl brine injected with CO2 at controlled P=100bar, T=40°C conditions   for 30days during which the chemical composition of the brine was regularly analysed. The elemental variations of the brine reacting with the reservoir samples reflect the dissolution of the present mineralogical phases, namely the K-feldspar, pyrite and clay minerals, and in some cases the precipitation of new phases, such as opaline silica.

The composition of the brine reacting with the caprock, registered an increase in Ca content at the first 2 days, interpreted as being the result of the limestone dissolution, without further variation throughout the experiment with a constant pH (6.36-6.57).

The identification of newly formed phases and evidence of dissolution as future and ongoing work are fundamental in understanding the entire process and predictability of the reservoir and sealant.

The work is funded by H2020 – STRATEGY CCUS (grant No. 837754)and national funds through FCT – Fundação para a Ciência e Tecnologia, I.P., in the framework of the UIDB/04449/2020 and UIDP/04449/2020 – Laboratório Hercules; UID/04292 - MARE-Centro de Ciências do Mar e do Ambiente and; UIDB/04683 and UIDP/04683 – Instituto de Ciências da Terra program.

How to cite: Jorge, P., Patrícia, M., Carlos, R., Andrew, K., Katriona, E., Mark, W., Paula, A., João, B., and Júlio, C.: Preliminary assessment of CO2 storage potential of deep saline aquifers in the Lusitanian Basin, (Portugal): mineralogical and chemical constrains, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18282, https://doi.org/10.5194/egusphere-egu25-18282, 2025.

Geometallurgy has emerged as a critical approach for understanding unconventional ore deposits, leveraging advanced techniques such as automated mineralogy and diagnostic leaching to characterize the behavior of complex ores. In the Philippines, the Carmen quartz-pyrite-gold (QPG) veins in the Mankayan Mineral District exemplify such a deposit, where copper occurs as arsenic-bearing tennantite and enargite. The ore's complexity is emphasized by intricate mineral textural relationships and its deleterious nature. Understanding its ore’s mineralization characteristics is imperative for the improvement of mineral processing and metal extraction.

The main orebody of the Carmen QPG vein is a silicic hydrothermal breccia intersected by multiple sulfide veins. Petrographic analysis reveals a predominance of tennantite with minor enargite-luzonite, closely associated with quartz and pyrite, the primary gangue minerals. Trace inclusions of chalcopyrite, bornite, chalcocite, and covellite are also observed replacing the primary minerals. Automated mineralogy, performed using a Mineral Liberation Analyzer (MLA) on whole and ground ore, provided valuable insights into the processing behavior of these arsenic-bearing minerals. Mineral maps of whole and comminuted samples reveal complex and pervasive textures at the microscopic scale. Tennantite is commonly associated with enargite (22.79%), pyrite (21.71%), and quartz (30.07%), while enargite is associated with tennantite (34.45%), pyrite (6.72%), and quartz (17.98%). Particle size distribution data indicate a convergence in the grinding behavior of enargite and tennantite with increasing fineness. Both minerals exhibit similar liberation trends, where larger size fractions contain a higher proportion of binary and ternary+ particles that progressively liberate with finer grinding. However, enargite consistently shows a higher proportion of liberated particles per size fraction compared to tennantite. Diagnostic leaching studies are currently underway to further evaluate the leaching behavior of arsenic, aiming to inform strategies for the effective beneficiation of this unconventional ore.

How to cite: Andal, K. G., Gabo-Ratio, J. A. S., Tungpalan, D. K. T., Manalo, P. C., and Taylan, R.: Characterizing arsenic mineralization in the Carmen Quartz-Pyrite-Gold (QPG) Veins, Mankayan Mineral District, Philippines: A geometallurgical approach, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18092, https://doi.org/10.5194/egusphere-egu25-18092, 2025.