Environmental and Earth Sciences

Abstract: The Jiaduoling area is located in the northern segment of the Southwest Sanjiang Metallogenic Belt, a region characterized by complex geological structures and abundant mineral resources. This study systematically identifies the spatial correlation between subsurface magnetic bodies and tectonic structures by utilizing 1:50,000 high-precision aeromagnetic data. Advanced processing techniques—including upward continuation, vertical derivatives, total gradient modulus, and Euler deconvolution—were integrated to refine the structural framework and clarify the mechanisms of fault-controlled mineralization.The results indicate that the aeromagnetic anomaly pattern is predominantly governed by NW-trending faults. Specifically, the deep-seated major fault F1 (with a calculated depth exceeding 3 km) served as the primary migration channel for ore-forming fluids, while secondary faults created localized ore-hosting spaces. Physical property analysis reveals a significant magnetic contrast, where Mesozoic intermediate-acid magmatic rocks act as the essential source for mineralization, providing both material and thermal energy for the formation of porphyrite-type iron deposits.Based on these findings, a three-dimensional "aeromagnetic anomaly-structural framework-mineralization" correlation model was established. Finally, two high-potential metallogenic prospective zones (P1 and P2) were delineated, providing precise geophysical evidence and strategic guidance for regional mineral exploration and the targeting of concealed ore bodies.

Abstract: Rockfall from slope unstable rock masses, a typical geological hazard induced by brittle failure, is characterized by abrupt occurrence, negligible macroscopic deformation prior to failure, and extremely short lead time for early warning, posing a severe threat to the safety of mountainous transportation systems, water conservancy and hydro-power projects, and urban settlements. Conventional static analysis methods have sig-nificant limitations in real-time acquisition of damage evolution of structural planes and dynamic assessment of stability changes, which can hardly meet the practical re-quirements of early warning for unstable rock masses. The dynamic evaluation method for the stability state of unstable rock masses, based on the principles of structural dy-namics, establishes a correlation model between dynamic parameters (natural fre-quency, damping ratio, mode shape, etc.) and the damage degree of structural planes, providing a new paradigm for dynamic identification and quantitative evaluation of the stability of unstable rock masses. This paper systematically reviews the dynamic behavior mechanism and theoretical evaluation framework of slope unstable rock masses, and elaborates on the damage evolution of structural planes, the disturbance effect of environmental dynamic loads, and the key dynamic parameter system. The single-degree-of-freedom dynamic models and their theoretical derivation for three typical types of unstable rock masses (sliding-type, toppling-type, and falling-type) are thoroughly analyzed, and the cutting-edge advances such as multi-block chain collapse model and data-physics dual-driven surrogate model are reviewed. Meanwhile, the contact and non-contact monitoring methods based on Micro-Electro-Mechanical System (MEMS) and Laser Doppler Vibrometer (LDV) techniques, as well as the de-velopment status of cloud-edge collaborative intelligent early warning architecture, are systematically summarized. On this basis, the core challenges are pointed out, includ-ing the long-term evolution under multi-field coupling, high-fidelity inversion calcu-lation for large-scale rock masses, and the scientific correlation between early warning thresholds and failure probability. The full-life-cycle dynamic simulation based on digital twin is also prospected. The research results provide a systematic reference for the improvement of the theoretical system of dynamic evaluation of slope unstable rock masses and the engineering practice of disaster prevention and mitigation.

Abstract: This paper focuses on the problem of anticipating the local occurrence of future large earthquakes. "Local" is defined as the probability of a large earthquake occurring with a defined circle of arbitrary radius surrounding a point of interest. The main (and for that matter, the only) assumption for all these works is that the Gutenberg-Richter (GR) magnitude-frequency relation holds. Here we describe a method for computing calendar time forecasts in a local area for large earthquakes of a target magnitude MT using a count small earthquakes MS < MT in the area. Using the idea that the GR relation is valid throughout the surrounding region, we define an ensemble of earthquakes in larger surrounding regions to be used in computing the forecast. What follows is simple data mining. The method has significant skill, as defined by the Receiver Operating Characteristic (ROC) test, which improves as time since the last major earthquake increases. The probability is conditioned on the number of small earthquakes n(t) that have occurred since the last large earthquake. The probability is computed directly as the Positive Predictive Value (PPV) associated with the ROC curve. The method is validated by comparison to the UCERF3 forecasts for the UCERF3-defined geographic boxes centered on Los Angeles and San Francisco. The method is then applied to a 125-KM radius circular area around Los Angeles, California, following the January 17, 1994 magnitude M6.7 Northridge earthquake, and short term forecasts (1 year and 5 year ) are computed.

Abstract: This study presents a comprehensive geospatial framework for landslide risk assessment across the 4,523 km road network of the Region of Epirus in Greece. Utilizing a field-verified inventory of 295 active landslides, the research evaluates five key predisposing factors—lithology, slope inclination, elevation, land use, and cumulative annual precipitation—using the bivariate Frequency Ratio (FR) statistical model. Among six tested scenarios, the most robust model integrated all factors, achieving high predictive accuracy by classifying nearly 80% of the study area within Moderate to Very High susceptibility zones. The resulting Landslide Susceptibility Index (LSI) was converted into a Landslide Hazard Index (LHI) and integrated with a weighted Road Vulnerability Map, which categorized road sectors based on functional importance and traffic volume. The final Landslide Risk Map indicates that the most critical risk zones are clustered along major transportation corridors that traverse geologically weak formations, moderate to high precipitation areas and steep mountainous sectors. This quantitative approach provides a vital decision-support tool for regional authorities, enabling the prioritization of geotechnical monitoring and the strategic allocation of resources for infrastructure stabilization. The methodology offers a replicable workflow for enhancing the resilience of transportation networks in landslide-prone Mediterranean regions facing evolving climatic threats.

Abstract: The color origin of precious coral, a highly valued organic polycrystalline gemstone, has long remained elusive. In this study, an integrated approach employing spectrophotometry, Raman, FTIR, and UV-Vis spectroscopy, coupled with Spearman correlation analysis, was utilized to investigate a color-graded series of precious coral samples ranging from white to red. The results demonstrate that the calcareous skeleton consists exclusively of calcite. The actual chromophores are identified as a blend of multiple distinct polyene species, characterized by Raman shifts at 1126 and 1515 cm⁻¹. Inherently exhibiting a red-orange hue, the progressive accumulation of these polyenes drives a systematic color transition from orange to red.Both absorption bands at 314 nm and 532 nm in the UV-Vis spectra originate from the polyene pigment molecules. Specifically, the broad 532 nm band is dominated by π-π* electronic transitions. As the pigment concentration increases, this band exhibits pronounced broadening and enhancement, accompanied by a redshift of the maximum absorption peak. This spectral evolution leads to an intensified absorption in the yellow-orange region, elucidating the intrinsic mechanism underlying the color transition of precious coral from orange to red with increasing pigment content. This work lays a solid foundation for the non-destructive identification of precious corals and future research on their color genesis.

Abstract: Three-dimensional geological structural modelling provides the geometric framework for subsurface exploration and development. However, conventional workflows, driven primarily by seismic interpretation, often lack explicit constraints from expert knowledge and are difficult to update when interpretations evolve. This study proposes an intelligent modelling methodology guided by a geological structure knowledge graph. The method includes: (i) a Three-tier Knowledge Architecture (TKA) that formalises domain knowledge in entity, relationship and inference layers using RDF/OWL; (ii) a Knowledge-driven Intersection Line Generation Algorithm (KILGA) coupled with a hierarchical adaptive mesh refinement scheme based on a posteriori error estimation (HAMR-APEE) to integrate geological constraints and mitigate boundary aliasing; and (iii) a bidirectional linkage mechanism between the knowledge graph and 3D models to support incremental updates following knowledge revision. The approach is validated in three petroliferous basins in China (Ordos, Qaidam and Sichuan), representing micro-amplitude, thrust nappe and deep complex structural styles. Compared with a conventional Petrel-based workflow, the proposed method reduces modelling RMSE from 15–20 m to 5–8 m, improves geological reasonableness from ~85% to >95%, and shortens modelling cycles from months to weeks.

Abstract: Gas hydrates are ice-like compounds formed from water and methane under high-pressure, low-temperature conditions in marine sediments. They influence sediment stability, fluid flow, and hydrocarbon distribution in continental margin settings. This study employs advanced seismic attribute analysis to investigate the gas hydrate stability zone (GHSZ) in the Gulf of Mexico and to assess the relationship between hydrate presence, subsurface fluid flow, and sediment deformation.Seismic attributes, including coherence, amplitude, and spectral decomposition, were applied to 3D seismic reflection datasets covering structurally complex regions of the northern Gulf of Mexico. These attributes were used to map bottom-simulating reflectors (BSRs), gas chimneys, and fault/fracture systems. Results indicate that gas hydrate stability zones are strongly associated with structural highs, fault intersections, and areas of enhanced deformation.The study finds that fault-controlled fluid pathways significantly influence hydrate distribution and sediment deformation patterns, highlighting the need to integrate seismic attribute analysis in hydrate resource assessment and geohazard evaluation. These findings provide new insights into fluid migration mechanisms and sediment dynamics in hydrate-bearing marine environments.

Abstract: The sound speed profile (SSP) is a core environmental parameter for underwater acoustic detection, navigation, communication, and other applications. However, its accurate acquisition is constrained by the sparsity of observational data and the ill-posed nature of inversion problems. This paper systematically reviews the research progress of SSP inversion under sparse observation constraints: it combs the technical evolution from physical model-driven methods (Matched Field Processing, MFP; Compressed Sensing, CS) to data-driven approaches (Dictionary Learning, DL; Machine Learning, ML), and classifies and compares the principles, applicable scenarios, advantages, and disadvantages of mainstream methods. It integrates typical measured cases from existing studies (including mesoscale eddy monitoring, underwater navigation and positioning, etc.) and quantitatively analyzes the inversion accuracy and practical value of different technical routes. The research shows that fusing physical constraints with multi-source sparse data (remote sensing, in-situ discrete measurements) is the core direction to balance inversion accuracy, efficiency, and cost. This paper provides a comprehensive reference for technical selection in fields such as marine national defense and resource exploration.

Abstract: The pre-Cenomanian Nubia sandstone is considered as one of the most productive reservoirs in the Gulf of Suez, Egypt. Determination of its reservoir rock type (RRT) is a crucial process in reservoir characterization and modeling, especially when the reservoir is extremely heterogeneous. In this study, an effort was made to bridge the gap between various techniques to determining RRT, which include lithofacies, traditional methods (x-y crossplots), and machine learning (ML). To accomplish this, the objectives of this study were accomplished through the utilization of sedimentological core description, routine core analysis, and conventional logging data from two wells (well A and well B) in the southern Gulf of Suez. The results show that the complete Nubia interval in the southern Gulf of Suez can be distinguished into seven distinct lithofacies (LF1-LF7). The first six lithofacies are comprised of different types of sandstones, while the seventh is related to mudstone. The results show also that the fault-cutting, rather than stratigraphic reasons, was primarily responsible for the difference in Nubia thicknesses between the two studied wells. It is likely that the lower three lithofacies were separated from one another by unconformity surfaces. The traditional techniques used to predict the RRTs show that the normalized reservoir quality index (NRQI) was the most appreciated method to predict the Nubia rock types. On the other hand, K –means clustering and self-organizing maps (SOM) techniques based on raw logging data and principal component analysis (PCA) can properly predict the Nubia reservoir rock types when correlated with the Ward’s method, which is based on the core data. The reservoir rock quality ranged from poor to very good, with a domination of moderate reservoir quality in well A and very good reservoir quality in well B. This discernible difference in reservoir quality between the two wells was probably attributed to the consequences of the post-deposition diagenesis processes and the variation of the sandstone texture.

Abstract: Fracture networks strongly control fluid flow, reservoir connectivity, and production performance in carbonate systems, yet their multiscale architecture of complexity remains difficult to characterize from heterogeneous geological and geophysical datasets. Here, we introduce the Digital Transformer (DiT), a physics-informed computational framework that automatically analyzes and classifies fracture systems using spatially encoded visuonumerical primitives derived directly from physical measurements. Instead of relying on textual tokenization, the approach performs attention primitives tokenization of multiscale geophysical data. Clusters of absolute integer values act as computational tokens while preserving spatial topology and scale-invariant structure of the original system. The framework integrates two complementary environments: Muuk'il Kaab (MIK) for multidimensional metadata fusion and visualization, and SYM-Fractron, a hybrid binary-symbolic transformer for two-dimensional image analysis. Within this architecture, Digital Twins provide coupled visual and statistical representations of geological systems and their computational counterparts, enabling an interpretable taxonomy of natural fracture patterns while supporting well-trajectory optimization in the exploration of dolomitized carbonate reservoirs. In this view, fracture architectures become visionumerical primitives whose physics-informed tokenization opens a pathway from the architecture of natural complexity to its computational realization through Digital Twins.

Abstract: The Junggar Basin (NW China) is a polycyclic intracontinental basin formed within the Central Asian Orogenic Belt and characterized by multi-stage tectonic reactivation and composite petroleum systems. This study integrates tectonic evolution, source rock geochemistry, and basin modeling to clarify the spatial–temporal controls on hydro-carbon generation and accumulation. The basin evolved from Late Paleozoic rifting to Carboniferous–Permian collision, followed by Mesozoic thermal subsidence and Ce-nozoic inversion related to the uplift of the Tianshan. Major source rocks include Car-boniferous marine shales (total organic carbon 1.5–5%), Permian lacustrine deposits (up to 10–12% total organic carbon; hydrogen index up to 700 mg HC/g TOC), and Ju-rassic coal-bearing strata. Thermal maturity ranges from 0.6% to >2.0% vitrinite re-flectance, indicating multi-phase oil and gas generation and secondary cracking in deeply buried depocenters. Hydrocarbon accumulation differs across structural zones. Central depressions are dominated by deep gas generation and composite traps, whereas northwestern segments reflect lateral migration from Permian source kitch-ens. Cenozoic inversion significantly reactivated faults and controlled vertical migra-tion pathways. The results highlight that hydrocarbon distribution in the Junggar Ba-sin is governed by the synchronization of tectonic evolution and generation phases, providing predictive insights for exploration in polycyclic inversion basins.

Abstract: A comprehensive petrophysical analysis of 232 core samples from the J-III productive horizon (wells 182, 1136, and 8096), supported by routine laboratory analyses and X-ray diffraction (XRD) data from 70 samples, was carried out. Integration of reservoir-property parameters and mineralogical characteristics made it possible to establish genetic relationships between material composition, post-sedimentary transformations, and the formation of reservoir properties. The rock-forming framework is dominated by quartz, albite, and chlorite, while calcite—primarily of secondary origin—is confined to pore spaces, having precipitated during the diagenetic and catagenetic stages. Minor phases, including nacrite, kaolinite, chalcopyrite, molybdenite, and graphite, record superimposed hydrothermal events, with graphite indicating episodic exposure to elevated temperatures during the petrogenetic evolution of the rocks. Mineralogical heterogeneity is pronounced: quartz is ubiquitous and albite widely distributed, yet the abundances of calcite and chlorite show considerable variability. Statistical analysis reveals modal populations of albite and calcite, alongside a near-lognormal distribution of chlorite. Examination of paired mineral associations distinguishes clay-rich from clay-poor varieties and confirms the genetic independence of albitization, chloritization, and calcitization, as well as the secondary nature of carbonate mineralization. The J-III productive horizon is characterized by extremely poor reservoir properties: modal porosity is approximately 1%, more than 95% of the values are below 2%, and permeability is predominantly below 0.01 mD. These rocks therefore belong to the class of tight, low-porosity, and low-permeability reservoirs. Local storage anomalies are largely controlled by the development of microfractures. The lack of a consistent correlation between porosity and the extent of carbonation or dolomitization suggests that these processes exert only a subordinate effect on reservoir properties. Dolomitization is frequently accompanied by additional mineralization and compaction. However, when pore-space volume is preserved, it can lead to an increase in void ratio, as dolomite is denser than calcite while the total pore volume remains nearly unchanged. The reconstructed petrogenetic model involves the deposition of sandy-clayey material containing plagioclase and organic matter, followed by diagenetic and catagenetic transformations—particularly albitization and calcitization—that resulted in a dense, secondarily mineralized rock mass. Late tectono-hydrothermal reactivation led to the development of a fracture system, which governs present-day reservoir properties and serves as the main conduit for hydrocarbon migration and accumulation. Mineralization along these fractures confirms their fluid-conducting role. Experimental acid treatment demonstrated that permeability can increase by up to four orders of magnitude, revealing the presence of hidden storage capacity and mobilizable micropore systems. The J-III horizon is thus interpreted as a fractured reservoir, with a development strategy focused on identifying and mapping fracture zones and enhancing their connectivity through horizontal drilling and stimulation techniques.

Abstract: Conventional drilling and coring methods are inherently limited to providing one-dimensional geological data, which hinders accurate characterization of the spatial distribution of rock mass structures and properties. Mechanical disturbances during drilling often cause core breakage, further compromising the fidelity of in-situ geological representation. This study proposes an integrated approach combining borehole optical imaging and ground-penetrating radar (GPR) for enhanced characterization of rock mass structures. A dynamic exploration methodology is introduced, defined as an adaptive drilling layout workflow based on phased information feedback. The fundamental concept, key assumptions, boundary conditions, and field implementation procedures of this dynamic survey are systematically described. The integrated method was applied to a high-speed railway investigation project in the Tengzhou section, Shandong Province, China, where six boreholes were surveyed using both techniques. Results demonstrate that fused analysis of borehole optical images and GPR data effectively reveals rock morphology, fracture distribution, joint systems, fractured zones, and geological features such as rock veins. The method's complementary strengths—optical imaging providing high-resolution orientation data at the borehole wall and GPR extending detection radially into the surrounding rock mass—enable spatially enhanced characterization while partially mitigating the azimuthal ambiguity inherent in single-borehole radar measurements. A triangular borehole survey scheme is shown to be feasible for locating subsurface anomalies. The proposed dynamic exploration method effectively reduces borehole requirements compared to conventional grid layouts while successfully identifying common anomalous features through integrated analysis of optical imaging and GPR data. The method demonstrates practical applicability for detecting fractures with apertures greater than 1 cm and meter-scale cavities, with good consistency between the two techniques validating the feasibility of this integrated approach. The method's limitations, including resolution constraints and detection omission risks, are explicitly acknowledged, and risk control strategies are proposed. Overall, the dynamic exploration approach reduces investigation costs, accelerates project time-lines, and provides a practical framework for spatial characterization of rock mass discontinuities with minimal borehole requirements.

Abstract: Underground water flow in karst areas and changing water levels due to extreme rain can lead to creation of caverns and sinkhole hazard. Such is the historical experience of the Valaská village in central Slovakia. To better understand the current sinkhole threat in the village, we aim at detecting shallow caverns using microgravimetry. Our broader objective is to examine the capabilities of the Growth inversion methodology to detect and characterize shallow cave space. In our study we focus on the benefits and weak points of the Growth inversion approach, which is a free-geometry inversion method based on model exploration and growing source bodies. Since a sole gravimetric inversion produces ambiguous results, we pay attention to the role and setup of the several free user-adjustable inversion parameters of Growth. We examine tuning these parameters for specific needs of shallow cavities detection. Valaská experienced sinkholes in 1964, 1968 and 2019. That of 1964 is known for a curious loss of a horse sunk into a karst chimney. Our gravimetric work shows that the sinkhole hazard at the exposed lot in Valaská is ongoing despite the taken mitigation construction measures. The Growth approach proved to be applicable and useful in microgravimetric identification of sinkhole threat and detection of shallow caverns in karst.

Abstract: This paper presents an outline of a historical stone: the Marble of Campiglia, from Tuscany (Italy). A comprehensive review of the literature and archival documents, combined with a new detailed field survey, allowed us to revise the geological setting and exploitation history of this cultural heritage marble, which has been sporadically used since Etruscan times up to the present day. The Campiglia Marittima Marble (CMM) has a thermal-metamorphic origin related to the intrusion of a granitic pluton dated at about 5.4 Ma. This gave rise to a marble with peculiar textural, grain-size, and fracturing features that influenced the cultivation approaches and methods. The main exploitation periods of the CMM as an ornamental stone were the Etruscan-Roman age, the Renaissance, and the nineteenth century; currently, it is used only for industrial purposes. A great number of ancient quarries are located on the western slope of Monte Rombolo, probably due to the high variety of commercial marble types that can be found in the area and to its strategic position with an easy transport way to the Tyrrhenian Sea. This research is aimed to recall to the memory this historical marble and can also support the possible reopening of a few quarries for conservation purposes, for ensuring the Authenticity of the historical artefacts in which it was used.

Abstract: Porphyry copper deposits are strategic resources characterized by complex mineralization and high spatial non-stationarity. Traditional linear estimation methods like Ordinary Kriging often fail due to "smoothing effects" and a reliance on manual partitioning. This study proposes the GDF-ML framework, which integrates Geological Distance Fields (GDF) with machine learning to achieve high-fidelity grade modeling. By utilizing cKDTree for efficient spatial indexing, absolute coordinates are translated into Signed Distance Fields (SDF), creating "Spatial Fingerprints" that encode topological relationships between samples and geological entities. Results demonstrate that GDF-ML significantly outperforms Ordinary Kriging, increasing the R2 score from 0.3080 to 0.7696 on an independent test set while accurately reproducing the "barren core" and irregular high-grade zones. Furthermore, SHAP analysis validates the model's decision-making logic, aligning "intra-domain gain" effects with established metallogenic theories. This framework provides a scalable, automated methodology for dynamic resource evaluation, eliminating the inefficiencies of traditional workflows and supporting the digital evolution of modern smart mines.

Abstract: The Devene fault system, a major strike-slip structure at the boundary between the Balkan Range and the Moesian Platform in NW Bulgaria, remains a subject of debate regarding its Quaternary activity. This study investigates the shallow expression of the fault at two representative sites, Tri Kladentsi and Beli Breg, using high-resolution electrical resistivity profiling to differentiate tectonic deformation from climatically driven landscape evolution. At Tri Kladentsi, resistivity profiles confirm a steeply dipping structural boundary within the Miocene bedrock, juxtaposing limestone against sands. The overlying 25 m thick loess cover, however, remains sub-horizontal and undisturbed. Likewise, at Beli Breg, the complex architecture of stacked channel sequences and tributary deposits at the Ogosta River confluence reveals no identifiable fault displacement. Our results suggest a high degree of morphological mimicry, where asymmetric river valleys produced by selective erosion and differential loess accumulation superficially converge with tectonic signatures. The long-term left-lateral slip rate is estimated at 0.14–0.19 mm/yr based on a 20 km Miocene offset. Nevertheless, the lack of modern surface rupture indicates a deceleration of fault slip rate and a transition to a buried fault top during the Quaternary. These findings necessitate a re-evaluation of regional seismic hazard assessments, because the absence of continuous surface traces physically constrains the maximum earthquake potential.

Abstract:

The tectonic framework of the 2019 Mirpur seismic sequence was investigated using local seismic data. Moment tensor inversion was performed for the Mirpur mainshock (Mw=5.8) and its largest aftershock (Mw=4.7). The mainshock exhibited a low dip angle (~10°) and shallow focal depth, suggesting association with the Main Frontal Thrust (MFT). Contrary, the largest aftershock showed a comparatively higher dip angle, indicating deformation along a ramp or ramp-anticline structure. The stress regime was evaluated using moment tensor solutions from two locally inverted events, two Global CMT solutions and a published focal mechanism. The results indicated a maximum horizontal stress (SHmax) orientation of N07°E, consistent with the stress orientation of the 2005 Kashmir earthquake sequence and the regional compression driven by the Indian plate convergence. Aftershock relocation and spatial distribution patterns suggested post-seismic stress relaxation and possible activation of a higher-dip fault segment or ramp-anticline structure. Although a seismogenic depth of approximately 15 km was estimated, the concentration of seismicity around 10 km depth may involve the Main Himalayan Thrust (MHT). The Mirpur mainshock was triggered primarily by the movement along the MFT, whereas the subsequent aftershocks reflected post-seismic relaxation associated with the MHT and related ramp-anticline structures.

Abstract: A method for analyzing long-term (1997-2025) continuous records of low-frequency global seismic noise measured at a network of 229 broadband seismic stations distributed across the Earth's surface is proposed. The method is based on the use of nonlinear multifractal and entropy statistics, evaluated daily in successive time intervals. The method is based on the use of first-principal component analysis, correlation analysis, and parametric models of point process intensity. The relationships between changes in seismic noise properties and the response of noise properties to the irregularity of the Earth's rotation with the sequence of strong earthquakes, including those of a predictive nature, are investigated.

Abstract: Organic facies distribution exerts a primary control on hydrocarbon generation potential in clastic-dominated passive margin basins. This study evaluates the spatial and stratigraphic distribution of organic facies and their hydrocarbon potential in the Niger Delta Basin using an extensive organic geochemical dataset. A total of 715 source rock samples from onshore, shallow offshore, and deepwater wells were analyzed using total organic carbon (TOC) and Rock-Eval pyrolysis parameters (S1, S2, S3, HI, OI, Tmax). Organic facies were classified following the Pepper organofacies scheme to assess variations in organic matter type, richness, and generative potential across depositional settings and depobelts. The results show that source rocks of the Akata Formation are dominated by organofacies B and D/E, reflecting mixed marine and terrigenous organic matter with moderate to high hydrogen indices and predominantly oil-prone to mixed oil–gas generative potential. In contrast, source rocks of the Agbada Formation are characterized mainly by organofacies F, dominated by terrestrial organic matter with low hydrogen indices, indicating a gas-prone character. Cretaceous shales beneath the Niger Delta contain mixed organofacies D/E and F and locally exhibit fair to good hydrocarbon potential. TOC values range from 0.1 to 16.9 wt%, with the highest organic richness concentrated within the Akata Formation at depths of approximately 2800–4000 m. Spatial variations in organic facies distribution across depobelts reflect changes in depositional environment, sedimentation rate, and preservation conditions. These results confirm the Akata Formation as the principal effective oil-prone source rock in the Niger Delta Basin and provide important constraints for petroleum system analysis and deepwater exploration risk reduction.