Satellite-derived seasonal fluctuations in surface displacement and soil moisture: Implications for landslide activity

Carbon mineralization in geological formations is considered one of the most secure and permanent methods for long-term CO2 storage. While extensive studies have focused on reactive basaltic systems, the behavior of tight sedimentary rocks under CO2-rich conditions remains less understood, particularly regarding the coupling between mineral transformations and mechanical stability. This study investigates how mineral composition and micromechanical properties evolve in low-permeability sedimentary rock when exposed to CO2-rich water under simulated reservoir conditions (60°C, 10 MPa) for up to 8 weeks. Using a combination of scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy, X-ray diffraction, and nanoindentation, we tracked progressive changes at both the microstructural and mineral scales. Results revealed early dissolution of calcite, minor changes in clay minerals, and stable silicate phases. SEM images showed increasing porosity and surface roughness, while nanoindentation measurements demonstrated a continuous decline in both hardness and elastic modulus over time. These findings suggest that CO2–water–rock interactions in tight formations can lead to significant weakening of the rock framework, even as mineral trapping proceeds. Understanding this coupled chemical–mechanical evolution is essential for evaluating the long-term safety, sealing integrity, and performance of CO2 geological storage in sedimentary environments.

Granitic/rhyolitic and sedimentary reservoir rocks of the Upper Rhine Graben – trace element mobility during fluid-rock interaction

Recent studies have shown the interest of automating the classification of rock images using deep learning architectures. The biggest issue for practitioners when applying these methods to real-world data sets generated during mineral exploration is the long time required to create and label a data set. This study proposes a complete workflow to label and classify drill core photographs with minimal time required for labeling through five successive steps: i) using exploration drill core photographs, rock cores are separated from wooden trays using morphological operators; ii) feature descriptors are then extracted from rock images using color histograms for colorimetric information and Gabor filters for texture information; iii) features extractors then serve as input data for self-organizing maps (SOM) for generating clusters that can be partially labeled by geologists for generating a labeled data set with limited efforts, generating a data set made of labeled and unlabeled images; iv) the partially labeled data set can then be used to train either fully supervised or semi-supervised deep learning architectures for generating classifications; v) the classification model obtained can then be re-used on unseen data to automate logging process. This study presents this workflow separately for two different geological domains, namely a data set of sedimentary rocks classified according to the intensity of bleaching features and a data set of crystalline basement rocks classified by lithological domains. Software code and data set are made publicly available. • Development of a complete workflow to transform drill-core photographs datasets (directly obtained from mineral exploration) into a labeled dataset usable for deep-learning tasks. • Evaluation of the possibility of inferring lithological (for the basement subset) and alteration (for the basin subset) classes based on a self-labeling strategy. • Evaluation of the potential to improve classification accuracy by using unlabeled samples in a semi-supervised way.

Geodata fusion and deep learning-based improved lithological mapping: A case study from the autonomous district of Yamoussoukro

The Scotian Basin is a tectonically complex passive margin basin. Triassic salt and Jurassic carbonates are overlain by clastic Cretaceous and Cenozoic rocks that locally form petroleum reservoirs. Its thermal history included mid-Cretaceous lithospheric heating and episodic up-dip flow of hot brines from the deep basin, controlled by salt tectonics. The diagenetic minerals in sandstones were influenced by detrital composition, depositional lithofacies and burial history. Meguma terrane detritus had abundant deformable feldspar, mica, chlorite, and lithic clasts leading to permeability loss during compaction. The Late Jurassic–Early Cretaceous Sable River supplied abundant polycyclic quartz and detrital ilmenite. The eastern basin received more low-grade metamorphic quartz, lithic clasts, micas and feldspars, resulting in more common clay cements. Meteoric water during sea-level lowstands corroded seafloor diagenetic minerals and precipitated kaolinite and anatase. Quartz overgrowths are widespread in sandstones, except where clay coats, now berthierine or chlorite, protected quartz grain surfaces. Remaining porosity was largely filled by Fe-calcite. At depths >2 km, K-feldspars dissolved and created secondary porosity or were partially replaced by albite where faulting or stratigraphic fairways allowed removal of diagenetic products; otherwise clays and carbonate cements were precipitated. Widespread secondary porosity formed during fracturing synchronous with hydrocarbon charge and was partly filled by diverse late minerals, including barite, brookite and illite. Diagenetic chlorite rims preserved porosity in rapidly deposited thick sandstones in areas of volcanic ash supply. Regional trends in detrital composition and diagenetic assemblages are partially obscured by local effects of sedimentary facies and flow of hot brines. • Passive margin basin, complex salt tectonics, detrital supply, and thermal history. • Sable River deposited linear sandstone fairways, up which deep basin fluids flowed. • Eodiagenesis influenced by lithofacies whereas mesodiagenesis by brine fairways. • Hot brine impacted cementation rates and apatite annealing, less so oil maturation. • Feldspar and mica supply favoured clay cement, volcanic ash favoured chlorite rims.

Thermal effects produced by Cenozoic basaltic intrusions into Cretaceous sedimentary rocks of the Potiguar Basin, NE Brazil: Implications for hydrocarbon reservoirs

The distribution of the radiological characteristics of the natural radioisotopes 40K, 232Th, and 226Ra in the Upper Cretaceous-Lower Paleogene sedimentary rock samples collected from Wadi Queih area, Red Sea, Egypt, was measured using gamma-ray spectrometer with an NaI(Tl) detector. The sedimentary sequence under study was divided into four groups (A, B, C, D) according to the lithological variations and dominant rock type. The average activity concentrations of 226Ra, 232Th and 40K were 309.11 ± 15.49, 336.91 ± 16.62 and 887.58 ± 44.38Bq/kg for group (A); 240.95 ± 12.06, 396.49 ± 19.83 and 570.49 ± 31.93Bq/kg for group (B); 260.21 ± 13.03, 333.49 ± 16.68 and 568.54 ± 28.43Bq/kg for group (C); and 238.56 ± 11.93, 369.62 ± 18.75 and 633.32 ± 32.74Bq/kg for group (D), respectively. For 226Ra, 232Th, and 40K, the average activity concentrations in each of the four groups are higher than the UNSCEAR worldwide average values of 35, 30 and 400Bq/kg, respectively. The radiological hazard parameters that were used to evaluate the radiation hazards associated with the rock samples, the calculated values of these indices exceed internationally recommended limits in several cases, indicating a non-negligible radiological risk in some rock units, particularly phosphate-rich and cherty lithologies. These findings highlight the need for radiological safety assessments in regions where such rocks are used in construction or agriculture. Given the radiological threat to residents and the need for radiation protection precautions, the collected data offer a useful future database for estimating the impact of radioactive contamination in the studied area as well as in locations where the rocks are used as building materials or in agricultural reclamations. The results also offer baseline reference values that can support future environmental monitoring, land-use planning, and radiation protection policy.

This study delineates groundwater potential zones along the contact between the Tiruchirappalli Cretaceous formations and the Archaean crystalline basement using ground magnetic surveys. Magnetic susceptibility data were collected with a Proton Precession Magnetometer along six NW–SE profiles at 1 km station spacing and 5 km profile intervals, covering key locations in Perambalur district, Tamil Nadu. A total of 60 measurements were obtained, with magnetic intensity values ranging from 967 to 7 gammas and averaging 297 gammas. Higher values were recorded in crystalline rocks (967–300 gammas) and lower values in sedimentary rocks (300–7 gammas), enabling the delineation of the basement–sedimentary litho contacts. Data processing in Geosoft and ArcGIS produced total magnetic intensity, reduction-to-pole, directional filter, regional, and residual maps, which highlighted lithological contacts and fracture systems. NE–SW fractures correspond to lithological contacts, while NW–SE fractures represent neo-tectonic structural elements. Groundwater potential zones were identified using rank and weightage method which shows that the possible potential zones are along the litho contact and the intersection of NW-SE fractures with litho contacts. The findings confirm that magnetic surveys are an effective tool for locating groundwater-bearing structures in basement–sedimentary terrains.

Knowing the past temperature of the Earth is crucial for understanding the mechanisms driving climate change and biosphere evolution, but there is significant debate about the range of past temperature variation. Previous interpretations, largely based on oxygen isotope records, suggest that global temperature has generally declined over the past 539 million years, but substantial uncertainties persist. In this study, we introduce an independent estimate for long-term Phanerozoic temperature trends based on a large database of chemical weathering indices from siliciclastic sedimentary rocks, globally upscaled using a state-of-the-art general circulation paleoclimate model. Our results imply that Phanerozoic global temperatures remained within 10-30 °C, and that Paleozoic oceans had comparable temperatures to Mesozoic and Cenozoic oceans, in contrast to previous work suggesting that they were anomalously hot. This finding supports the idea that negative feedback processes, such as silicate weathering, have maintained long-term global average temperatures within a relatively tight range, contributing to the continued long-term evolution of the biosphere.

Research subject. The transverse (sub-latitudinal) structures of the sub-meridional Ural fold belt. Aim . To clarify the nature and age of the transverse structures and their metallogenic significance. Methods and materials . The analysis of geological, tectonic, and structural data on the sub-latitudinal structures throughout the Urals was performed. Results . The current knowledge of the transverse structures of the Urals has been reviewed and generalized. In the West Mugodzhar volcanic zone and the Irgiz synclinorium of the Mugodzhars, geological complexes corresponding to the deeper levels of the Magnitogorsk megasynclinoorium were brought to the Earth’s surface. Such exposure could only have resulted from a vertical uplift of approximately 5–8 km followed by erosion of Paleozoic rocks in the Mugodzhars. In the western sector of the Urals, the structural pattern differs markedly from that in the eastern sector. Here, beginning in the south – where the influence of the Caspian Depression is already pronounced – a gradual northward uplift is observed. This is accompanied by the progressive exposure, at the present-day erosion level, of increasingly ancient complexes, transitioning from sedimentary rocks in the south to metamorphic rocks in the northern part of the Southern Urals. The amplitude of uplift in these metamorphic complexes reaches at least 12 km. Thus, the vertical movements that caused the observed sublatitudinal zonation of the Urals in the south occurred in different directions in its western and eastern sectors. Conclusions . The observed lateral zonation of the Urals is primarily controlled by variations in the present-day depth of erosion across different regions. These variations, in turn, reflect differences in the rates and magnitudes of post-Paleozoic uplift, most notably during the Middle and Late Triassic. Consequently, lateral zonation is only indirectly related to the formation of pre-Mesozoic mineral resources in the region. Nevertheless, understanding the depth of erosion in different parts of the Urals is essential for metallogenic assessments. For younger mineral resources, such as hydrocarbons (oil and gas) and placer deposits, sub-latitudinal zonation plays a decisive role.

Deformation localization and failure mechanisms of sedimentary rocks: insights from acoustic emission and digital image correlation

Hydrothermal systems related to antimony (Sb) and gold (Au) ores form under low- to medium-temperature conditions (150−350 °C) and are often associated with major ore deposit belts. Ongoing debate surrounds the characteristics of ore-forming fluids, which are influenced by fluid sources, fluid-rock reactions, and evolutionary processes. Trace elements in quartz are critical for understanding fluid evolution in magmatic-hydrothermal systems (e.g., porphyry-epithermal deposits). This study analyzed trace elements in quartz from 43 Sb and Au deposits worldwide, focusing on low- to medium-temperature conditions. The deposits included Mesozoic Sb belts, Carlin-type and intrusion-related Au provinces in China, and late Paleozoic Sb-Au deposits in Europe. The findings reveal that Ti-Al geochemical diagrams indicate distinct affinities for the host rocks. Specifically, systems hosted by igneous rocks display elevated Ti/Al ratios (>0.005), whereas those hosted by sedimentary rocks exhibit lower ratios (<0.005). Metamorphic rock−hosted systems are best characterized by Sb-As plots and a ternary diagram involving (Ge + As)−Ti × 5−Sb. The observed relationships between Sb and As suggest that trends in Sb mineralization are more closely aligned with metamorphic rock−hosted systems, whereas trends in Au mineralization are associated with igneous rock−hosted systems in the current dataset. Sedimentary rock−hosted systems show quartz trace-element trends indicative of both Sb and Au mineralization. The Li-Al trends further highlight the distinct fluid evolution associated with Sb and Au mineralization, particularly in vein-type Sb, intrusion-related Au, and Carlin-type Au deposits. Variations in trace elements within quartz are attributed to compositional changes induced by cooling. Our results demonstrate that the trace-element signatures identified in quartz provide new insights into the evolution of fluids in low- to medium-temperature hydrothermal Sb and Au systems.

Rock identification plays a fundamental role in geological work, particularly in resource reservoir characterization, stratigraphic division, engineering stability assessment, and hazard prevention. However, traditional manual identification approaches exhibit low efficiency and limited ability to capture dynamic and fine-grained features. To address these challenges, this study employs image recognition and object detection techniques to classify igneous, sedimentary, and metamorphic rocks. We propose an improved You Only Look Once version 11 (YOLO11)-based model by integrating the Efficient Visual State Space (EVSS) module, which enhances the extraction of key rock characteristics-such as texture and fractures-by modeling long-range spatial dependencies and overcoming the locality limitations of conventional convolutional networks. The proposed method is evaluated against three mainstream deep learning models. Experimental results show that the EVSS-enhanced YOLO11 achieves the highest classification accuracy of 92%, outperforming the Vision Transformer (ViT, 85%), ResNet (74%), and the standard YOLO11 (87%). In object detection tasks, the EVSS-integrated YOLO11 also demonstrates superior performance, achieving a mean average precision at 50% intersection-over-union (mAP50) of 91.8% compared to 87.7% for the original YOLO11. By combining efficient visual feature modeling with multi-scale detection capability, this study confirms the effectiveness and robustness of the EVSS-YOLO11 framework for rock image identification, providing strong technical support for intelligent geological analysis.

Abstract The multimillion-ounce Fenelon gold deposit is a postvolcanic pre-Timiskaming deposit located in the north-western part of the Neoarchean Abitibi greenstone belt, Canada. Two stages of epigenetic gold mineralization are recognized: an early stage (M1) characterized by quartz veins with native gold and molybdenite, and a later stage (M2) with sulfide-rich mineralization accompanied by native gold and Bi-Ag tellurides. Both occur within high-strain zones along lithological contacts and foliation planes. Multiple sulfur isotope analyses of M2 pyrrhotite, chalcopyrite, arsenopyrite, and pyrite yielded near-zero Δ33S values and positive δ34S values (+2.0‰ avg), contrasting with those for diagenetic pyrrhotite in the sedimentary host rocks (Δ33S = +0.45‰ avg, δ34S = +0.6‰ avg). Some sedimentary-rock-hosted mineralization exhibits elevated Δ33S values (up to +0.54‰) and lower δ34S values (down to +0.90‰), consistent with local dissolution and reprecipitation of sedimentary sulfide. The sulfur isotope signature is that of fluids exsolved from crystallizing intrusions or metamorphic devolatilization of igneous rocks. A progressive increase in δ34S values is observed throughout the paragenesis, including within concentrically zoned M2 pyrite, where δ34S values increase from cores (+1.7‰ avg) to rims (+3.6‰ avg), accompanying inclusions of native gold and pyrrhotite. This trend is consistent with a progressive decrease in fluid fO2, likely due to interaction of the fluid with graphite in the sedimentary host rocks. These results show that the Fenelon deposit is either an intrusion-related deposit or, less likely, an early orogenic deposit formed from metamorphic fluids derived from igneous rocks. The results also underline the importance of fluid reduction by carbonaceous sedimentary rocks in gold mineralization.

The purpose of this article is to summarize the data of engineering and geological surveys conducted in the 1970–1990s in the town of Neryungri in Southern Yakutia. According to the surveys, the foundation of engineering structures is composed of an unfrozen-frozen layer of coal-bearing sedimentary rocks, whose main lithotype is sandstones, which are also the object of study. The subject of the study is laboratory values of the uniaxial compressive strength of sandstone samples in the air-dry and water-saturated states. Variability of sandstone sample strength in the annual heat cycle layer was studied using probability theory and mathematical statistics. Using laboratory data, the strength of a sandstone massif at the depths of 2–11 m was estimated with 90 % reliability. The strength of the fractured part of sandstones was studied sporadically at depths of up to 22.5 m. The unbalanced probability distribution of strength near the mean values was interpreted as a natural defect of sandstones associated with their decompression by tectonic and exogenous-cryogenic processes. The defect is correctly approximated by the Weibull law.The strength of the sandstone massif in air-dry and water-saturated conditions varies from very low to very high. The proportion of rocky sandstones with the strength above 120 MPa is 78.9 %. The proportion of semi-rocky sandstones with the strength below 15 MPa is 12.1%. The background strengths of air-dry and water-saturated rocky sandstones range from 54.49 to 171.42 MPa and from 32.14 to 135.78 MPa, respectively. In the same conditions, the background strength values of semi-rocky sandstones are lower and range from 1.65 to 27.2 MPa and from 0.67 to 10.12 MPa. When the material is saturated with water, the variability of its strength decreases by a factor of 4. This pattern is explained by the loss of structural-petrographic, cryogenic-thermal, and temperature-moisture diversity in sandstones when they are soaked in water. The conducted studies led to the following conclusion: predicted based on laboratory data strength of the sandstone massif with the approximate reliability of 80 %, is sufficient for the safe operation of engineering structures in Neryungri.

Weathering plays a central role in the geological carbon cycle. Silicate mineral weathering is invoked as a stabilizing feedback on CO2 emissions, for example from volcanism during the emplacement of Large Igneous Provinces. However, modern-day studies show weathering can emit CO2 during oxidation of rock organic carbon (OCpetro) in sedimentary rocks and function as a positive feedback on climate warming. Here we measure the rhenium isotope composition (δ187Re) of Early Jurassic marine sediments to explore how OCpetro oxidation rates changed during warming across the Toarcian Ocean Anoxic Event (T-OAE). We find a 0.22 ± 0.10‰ decrease in δ187Re values during the T-OAE, with mass balance modeling showing this can be explained by increased OCpetro weathering intensity on land associated with 6-7 °C of global warming. We estimate this could have delivered 7600-20,490 PgC to the oceans and atmosphere, demonstrating that chemical weathering does not simply act as a stabilizing feedback during hyperthermal events.

Numerous studies have demonstrated that the nitrogen isotopic composition (δ15N) of sedimentary rocks is not significantly modified by thermal maturation, making it a reliable tool for examining sedimentary redox conditions. However, reports on δ15N values of crude oils are scarce due to technical challenges in measurement. This study presents δ15N analyses of crude oils from the Paleogene Shahejie Formation in the Dongpu Depression in the Bohai Bay Basin, aiming to unravel their geological and geochemical implications. The results reveal distinct δ15N characteristics among crude oils from different oilfields: oils derived from anoxic source rocks exhibit lower δ15N values, while those from less anoxic/suboxic source rocks show higher values. Crude oils from mixed-source rocks display intermediate δ15N values. Specifically, δ15N values range from 14.6 to 17.6‰ for oils from the Wenmingzhai and Weicheng oilfields, from 21.9 to 25.7‰ for those from the Guyunji oilfield and Pucheng-Weicheng transitional zone, and from 15.3 to 21.4‰ for oils from the Pucheng and Wenliu oilfields. In contrast, organic carbon isotopic compositions (δ13C) of crude oils from the six oilfields show no significant differences, ranging from -28.6 to -27.0‰. Combined with biomarker indices and oil-source correlation results, this study confirms that sedimentary redox conditions play a pivotal role in shaping the δ15N values of crude oils. Furthermore, δ15N may serve as a valuable parameter for the classification and oil-source correlation of crude oils with similar organic matter sources owing to its high sensitivity to redox conditions.

The Tibetan Plateau is an assemblage of continental blocks rifted from Gondwana and accreted to Eurasia after the closure of several Tethyan oceanic branches. The Ganzi-Litang ocean, as an eastern branch of the Paleo-Tethys, has been subject to a long debate particularly regarding its opening time, nature, and relationship with the Emeishan mantle plume. Here we present detailed field investigation combined with petrographic, geochemical, and geochronological analyses on mafic and sedimentary rocks from the Ganzi-Litang mélange zone. The 281.9 ± 3.8 Ma cumulate gabbro and associated enriched mid-oceanic-ridge-type basalts in the Ganzi ophiolitic complex indicate the Ganzi-Litang ocean initially formed in the Early Permian. Then the Middle−Late Permian Emeishan plume generated seamounts in the Ganzi-Litang ocean, as recorded by newly identified ocean-island basalt (261−254 Ma) capped by radiolarian cherts in the Litang area. These mafic rocks are characterized by high TiO2 (3.1−4.2 wt%) and Ti/Y, with positive zircon εHf(t) of +5.0 to +10.3 and whole-rock εNd(t) of 0 to +1.0, closely matching the signature of high-Ti Emeishan basalts. The occurrence of continental margin-type cherts and of Emeishan basalts along the suture allow us to envisage the Ganzi-Litang embryonic ocean as part of the hyper-extended margin of the South China Block that underwent further extension related to the emplacement of the Emeishan plume. These findings not only shed new light on the paleogeographic evolution of the eastern Paleo-Tethys but also have important implications for the regional exploration of Emeishan plume-related Fe−Ti−V ore deposits.

Abstract Detrital sediments that accumulate downstream and are preserved in sedimentary rocks can allow characterization of geologic formations that are inaccessible for spatial or temporal reasons. However, mixing, sorting, and alteration of sediment during transport may complicate reconstruction of protolith characteristics. We test the preservation of three key provenance signals in coarse fluvial sand at a Mars analog watershed in Iceland to determine whether detrital sediments capture (a) watershed magmatic chemical variation, (b) textural indicators of lava‐water interaction during eruption and cooling, and (c) hydrothermal alteration. Specifically, we tested whether diagnostic variations in rock mineralogy, chemistry, and texture can be recovered in the bulk mineralogy and chemistry of sand‐sized sediments. In first‐order basaltic fluvial sediments transported <10 km, sediment sorting segregated grains with distinct inherited cooling textures and phenocrysts, and rendered some altered materials undetectable in bulk measurements of sand. This sorting also obscured signals of magmatic variability across the watershed and reduced the range of recorded lava cooling rates. The input of exogenous tephra to the Sandvatn watershed could only be distinguished in depositional environments with minimal active deposition or erosion and was most evident in reworked lakeshore deposits far from the delta. Bulk chemistry and mineralogy recorded different aspects of sediment sorting at Sandvatn, highlighting that integrating paired chemical and mineralogic data is key to disentangling the records of provenance composition and texture from sorted volcanic sediment.