Search Results (287)

The Jiaodong Peninsula hosts one of the largest gold provinces in the world. The Xincheng gold deposit, located within the Jiaojia gold metallogenic belt, is the largest deposit in this belt and represents a super-large fractured alteration-type gold deposit hosted in fracture zones with relatively well-preserved conditions. Mineralization and hydrothermal alteration are controlled by the Jiaojia Fault zone and its subsidiary faults. The Jiaojia Fault (JJF) serves as the principal ore-hosting structure of the Xincheng deposit, and its multi-stage activity has governed the mineralization, subsequent modification, and preservation of the deposit. However, the post-mineralization cooling, uplift, and exhumation history of the deposit remains poorly constrained. In this study, zircon and apatite fission-track thermochronology analyses were conducted, and inverse thermal history modeling of apatite was performed to reconstruct the tectonic-metallogenic evolution of the Xincheng gold deposit. The zircon fission-track ages range from 90.0 ± 4.0 to 118.0 ± 5.2 Ma, which are younger than the mineralization age (~120 Ma), indicating that the region experienced widespread cooling during the Late Early Cretaceous. This cooling event was likely related to crustal uplift and exhumation triggered by a transformation of the tectonic regime. The apatite fission-track ages range from 15 ± 1.8 to 38 ± 2.7 Ma, recording the Cenozoic cooling and uplift history after mineralization. The inverse thermal history modeling results show that the post-mineralization cooling process can be divided into three stages. The first stage, from 42 ± 5 to 30 ± 4 Ma, is characterized by rapid cooling, with an average cooling rate of 4.23 °C/Myr. The second stage, from 30 ± 4 to 12 Ma, represents a period of slow cooling, with an average cooling rate of 0.98 °C/Myr. Since 12 Ma, the third stage has been marked by renewed rapid cooling, with an average cooling rate of 4.17 °C/Myr. Variations in cooling rates among different stages reflect adjustments in the regional tectonic stress field and the influence of activity along the JJF. Based on the fission track thermochronological data and a reasonable estimate of the geothermal gradient, the total amount of exhumation since 120 Ma is calculated to be approximately 8.22 km. Integration of these results indicates that the shallow portion of the deposit has undergone a certain degree of erosion; however, the overall preservation conditions remain favorable, and significant exploration potential persists at depth and along strike. This study constrains the post-mineralization cooling and erosion history of the Xincheng gold deposit, reveals the controlling role of multi-stage tectonic activity on deposit preservation, and provides new temporal constraints and a scientific basis for preservation assessment and deep exploration of gold deposits in the Jiaodong Peninsula and in regions with similar tectonic settings. Full article

The Mw 6.4 Petrinja earthquake on 29 December 2020 ruptured the Petrinja-Pokupsko fault system in central Croatia, producing widespread coseismic deformation and subsequent postseismic processes. This study examines ground displacements in the Petrinja area from 2019 to 2022 using Sentinel-1 SAR data processed with SBAS time series analysis. Interferometric phase residuals were filtered using temporal coherence masking and RMS cut-off criteria to ensure high-quality displacement estimates. Line-of-sight (LOS) velocity fields were derived separately for ascending and descending tracks, combined into horizontal and vertical components, and rotated into a fault-parallel direction. Fault-parallel velocities were also extracted with pixel-wise coseismic offsets removed to isolate postseismic transients. Pre-event displacements are generally small and often within measurement uncertainties. However, because the 2019–2022 observation window includes the mainshock and concentrated early postseismic motion, robust estimation of long-term interseismic rates (millimeters per year) is not possible from this dataset. Such rates from independent regional GNSS measurements are therefore included solely for tectonic context and visual illustration. A clear surface displacement jump exceeding 20 cm was detected, with opposite signs in ascending and descending geometries, reflecting predominant right-lateral strike-slip motion. Following the removal of the coseismic jump, weighted profile analysis identifies residual transients of up to ±1.5 cm/yr near the fault, consistent with dominant shallow afterslip. Possible contributions from viscoelastic relaxation are noted, as such processes produce broader, longer-timescale deformation patterns that cannot be excluded without extended observations or forward modeling. These geodetic observations quantify the immediate postseismic deformation and provide constraints on near-fault slip patterns following the mainshock. Full article

This study investigates the rare-earth element (REE) geochemistry of twenty-nine clastic rock samples from the Paleogene Liushagang Formation in the Weixi’nan Sag. The primary objectives were to quantitatively evaluate the depositional paleoenvironment, determine the provenance lithology, and constrain the tectonic setting of the source area. Results reveal distinct chondrite-normalized REE distribution patterns characterized by light REE (LREE) enrichment, relatively flat heavy REE (HREE) segments, and pronounced negative Eu anomalies. The cerium anomaly index (Ce_anom, normalized to the North American Shale Composite) ranges from −0.06 to 0.00, implying broadly suboxic to anoxic-reducing conditions in the water column during deposition. The chondrite-normalized (La/Yb)_N ratio, utilized as a proxy for relative depositional residence time, decreases stratigraphically from member 3 to member 1, reflecting a transition to shorter residence times and higher relative sedimentation rates. Laterally, (La/Yb)_N increases toward the basin center, accurately recording progressively lower sedimentation rates basinward. Provenance analysis indicates that the sediments were predominantly derived from felsic igneous rocks of the upper continental crust. Spatially, the northern steep-slope belt reflects a uniform source, whereas the southern gentle-slope belt and the Weixi’nan low-uplift periphery record multisource mixed inputs. Finally, tectonic discrimination reveals an “active continental margin” affinity. This geochemical signature represents the inherited tectonic environment of the Mesozoic parent rocks in the surrounding source uplifts, rather than the Cenozoic extensional rift setting of the Weixi’nan Sag itself. Full article

Copper is a critical metal for the global energy transition. Yet, declining discovery rates and increasing demand necessitate more efficient mineral exploration strategies grounded in a mineral systems approach. The Carajás Province (Amazonian Craton, Brazil) is one of the world’s premier copper-producing regions, hosting several iron oxide–copper–gold (IOCG) and related deposits. The Northern Copper Belt (NCB), located near the boundary between the Carajás and Bacajá domains, records a multiphase deformational and metallogenetic evolution from the Neoarchaean to Paleoproterozoic. Despite extensive previous studies, uncertainties remain regarding the geometry, depth, and continuity of the regional structures that control copper mineralization, as well as the nature of the tectonic boundary between the Carajás and Bacajá domains. As a result, through an integration of airborne magnetic, gravity, gamma-ray spectrometry, morpholineament, and spatial analyses, we characterized the tectono-structural framework of the NCB and the southern Bacajá Domain. This will provide new constraints on the geodynamic evolution of this world-class copper metallogenic belt, elucidating crustal-scale structures and patterns of hydrothermal alteration and fluid pathways, and enhancing understanding of the potential for further discoveries. Full article

This work deals with the quantification of long-term fault slip rates as a basis for seismic hazard assessment along a segment of the Eastern Messinia Fault Zone (EMFZ) in southwestern Peloponnese, Greece. Using cosmogenic ³⁶Cl exposure dating, it provides independent numerical constraints on recent deformation. The resulting late Holocene slip-rate estimates (~0.32–0.46 mm/yr) confirm ongoing fault activity, consistent with earlier paleoseismological and geomorphic studies, while indicating spatially distributed extension. These rates imply loading timescales of several hundred years for moderate (Mw ≈ 5.8–6.0) earthquakes. Although individual exposure ages cannot be uniquely associated with single seismic events, they offer robust benchmarks for cumulative displacement and long-term strain accumulation. Overall, this work demonstrates how numerical dating methods (particularly cosmogenic nuclide techniques applied to carbonate bedrock) can link geological observations with engineering requirements by constraining fault behavior over 10³–10⁵ year timescales and improving long-term seismic hazard evaluation in complex tectonic settings. Full article

The Eastern Cordillera of the Colombian Andes is a high-elevation asymmetric plateau subjected to NW–SE shortening. An interesting aspect of this plateau is the presence of high geothermal gradients (up to 52 °C/km), constrained by wells drilled in sedimentary basins. Radial and transverse receiver functions were computed at key sites in the plateau and the adjacent low-elevation foreland region to better understand the controlling factors of these anomalous gradients. Results indicate the presence of tilted anisotropic layers in the uppermost crust of the Cordillera, and nonexistent to weak anisotropy in the foreland region. The estimated SE fast-axis trend of the anisotropy is related to NNE-striking faults and top-to-the-east tectonic transport during deformation. We interpret the SE fast axis as being associated with shearing of NW-dipping faults in the plateau. Compiled thermochronological data point to high deformation and exhumation rates since the middle Miocene, which we use to propose that the rapid rise of deep and hot blocks along major regional faults is perturbing the background geothermal gradient. Regions near major thrust faults in the Eastern Cordillera are potential areas for geothermal energy exploration due to the perturbed geothermal gradient and enhanced fluid infiltration related to deep fault systems. Full article

Understanding landform evolution is essential for assessing how terrain responds to geomorphic drivers such as weathering, fluvial erosion, hillslope processes, and tectonic uplift. This is particularly important in applications such as constructed post-mining landform rehabilitation, where predicting long-term erosional stability is vital for sustainable closure planning. In addition to long-term average erosion rates, the spatial patterns of gullies, rills, and channels are critical for assessing landform stability. This review examines Digital Elevation Model (DEM)—driven, process-based Landform Evolution Models (LEMs), with a primary focus on SIBERIA, CAESAR-Lisflood, and SSSPAM, which are widely used to evaluate the erosional behaviour of constructed post-mining landforms, each with distinct characteristics. These models are systematically compared in terms of input requirements, process representations, parameterisation, and predictive capabilities. Recent advances in high-spatial resolution DEMs (e.g., LiDAR, SRTM), along with digital soil and rainfall databases and satellite-derived vegetation indices, have improved the parameterisation of erosion, hydrological, and sediment-transport processes of the LEMs. A brief comparative case study is presented to demonstrate how these LEMs simulate 1000-year erosional behaviour along a linear hillslope. This review synthesises the current capabilities and limitations of DEM-driven LEMs, providing guidance for researchers, land managers, and practitioners in selecting appropriate models to support sustainable post-mining landform management, as well as outlining potential future advancements. Full article

The Linfen–Yuncheng Basin is located on the southern edge of the Fenwei Fault Zone, influenced by intense tectonic activity, thick Quaternary sedimentation, and anthropogenic disturbance, it exhibits prominent characteristics of ground subsidence and fissure development. However, uncertainties still exist regarding the primary controlling factors of subsidence. This study employs multi-temporal InSAR data, combined with small baseline subset (SBAS–InSAR) technology to invert the high-precision ground line of sight deformation fields, and conducts time-series decomposition analysis using the Seasonal Trend Decomposition (STL) method. The results show that from 2017 to 2025, subsidence was mainly concentrated in the central and southern regions of the basin, with a maximum cumulative subsidence exceeding 200 mm and an average annual subsidence rate of −40 mm/year. Its spatial distribution is highly consistent with major structural zones such as the Zhongtiao Mountain Front Fault and the Linyi Fault, indicating that fault activity exerts a significant controlling effect on subsidence patterns. Groundwater level fluctuations are positively correlated with overall ground subsidence, and the response rate of different monitoring points is constrained by differences in aquifer depth and permeability. Groundwater aquifer points exhibit rapid and reversible subsidence response, while confined aquifer points are affected by low-permeability or compressible layers, showing a significant lag effect. The research results indicate that time-series analysis based on InSAR can not only effectively reveal the subsidence evolution process at different scales, but also provide a scientific basis for groundwater resource regulation, geological disaster prevention and control, and sustainable regional land utilization. Full article

Creeping landslides constitute the predominant form of long-term, slow-moving geohazards in high mountain gorge regions. Under the combined influence of gravity and external triggering factors, these landslides undergo persistent deformation, posing continuous threats to major transportation corridors, hydropower infrastructures, and nearby settlements. Li County is located within the active tectonic belt along the eastern margin of the Tibetan Plateau, characterized by highly variable topography, intensely fractured rock masses, and dense development of creeping landslides. The slip surfaces are typically deeply buried and concealed. Consequently, conventional drilling and profile-based investigations, limited by high costs, sparse sampling points, and poor spatial continuity, are insufficient for identifying the deep-seated structures of such landslides. To address this challenge, this study applies Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) to obtain ascending and descending deformation rate fields for 2022–2024, revealing pronounced spatial heterogeneity and persistent activity across three types of landslides. Based on the principle of mass conservation, the sliding-surface depths of eight typical landslides were inverted, revealing pronounced heterogeneity. The maximum sliding-surface depths range from 32 to 98 m and show strong agreement with borehole and profile data (R² > 0.92; RMSE ±4.96–±16.56 m), confirming the reliability of the inversion method. The GeoDetector model was used to quantitatively evaluate the dominant factors controlling landslide depth. Elevation was identified as the primary control factor, while slope aspect exhibited significant influence in several landslides. All factor combinations showed either “bi-factor enhancement” or “nonlinear enhancement”, indicating that slip-surface depth is governed by synergistic interactions among multiple factors. Boxplot-based statistical analyses further revealed three typical patterns of slip-surface variation with elevation and slope, based on which the landslides were classified into rotational, push-type translational, and traction-type translational categories. By integrating statistical patterns with mechanical models, the study achieves a transition from “form” to “state”, enabling inference of the internal mechanical conditions and evolutionary stages from the observed surface morphology. The results of this study provide an effective technical approach for deep structural detection, identification of controlling factors, and stability evaluation of creeping landslides in high mountain gorge environments. Full article

In order to address the challenges of soft coal texture, poor permeability, and wellbore instability in tectonic coal reservoirs, a new biodegradable fuzzy-ball drilling fluid combined with a bio-based surfactant and enzyme system was developed. The optimal formula was determined through single-factor experiments and orthogonal optimization: 6% KCl–2% trehalose composite base slurry + 4% carboxymethyl chitosan + 0.4% hydroxypropyl methylcellulose + 0.15% xanthan gum + 0.12% guar gum + 0.3% cocamidopropyl betaine + 0.15% lauryl alcohol + 0.2% triethanolamine, with the degrading agent consisting of 0.2% composite-modified amylase + 0.04% composite-modified cellulase. The performance evaluation results show that the drilling fluid has stable rheological properties in the temperature range of 40~60 °C (yield point-plastic viscosity ratio: 0.8~0.9) and low filtration loss (5.8~6.5 mL); it exhibits excellent inhibition on tectonic coal, the inhibition rate of linear expansion rate is 72.1%, and the 14-mesh rolling recovery rate is 82.5%; at 55 °C, the gel breaking rate reaches 96.9% after 1.5 h, the mud cake removal rate reaches 98.8%, and the permeability recovery rate reaches 84.8%. After applying this drilling fluid, the unconfined compressive strength of tectonic coal increases from 1.2 MPa to 2.8 MPa (an increase of 133.3%), and the triaxial compressive strength increases from 20.1 MPa to 38.5 MPa (an increase of 91.5%); the numerical simulation shows that the radial displacement around the wellbore decreases by 62.1% and the plastic zone area shrinks by 73.2%. This novel biodegradable fuzzy-ball drilling fluid has the characteristics of efficient wellbore stabilization, easy degradation, and low formation damage, providing effective technical support for the green development of coalbed methane in tectonic coal reservoirs. Full article

Understanding the spatial and temporal structure of crustal deformation is essential for identifying tectonic blocks, assessing seismic hazard, and detecting precursory deformation associated with major megathrust earthquakes. In this study, we analyze twenty years of continuous GNSS observations from the Japanese Islands to identify coherent deformation domains and anomalous regions using an integrated time-dependent clustering framework. The workflow combines six machine learning algorithms (Hierarchical Agglomerative Clustering, K-means, Gaussian Mixture Models, Spectral Clustering, HDBSCAN and consensus clustering) and constructs a set of deformation-related features including steady-state velocities, strain rates, co-seismic and post-seismic displacements, and spatial distance metrics. Optimal cluster numbers are determined by validity metrics, and the most robust segmentation is obtained using a consensus approach. The resulting spatiotemporal domains reveal clear segmentation associated with major geological structures such as the Fossa Magna graben, the Median Tectonic Line, and deformation belts related to Pacific Plate subduction. The method also highlights deformation patterns potentially associated with the preparation stages of megathrust earthquakes. Our results demonstrate that machine learning-based clustering of long-term GNSS time series provides a powerful data-driven tool for quantifying deformation heterogeneity and improving the understanding of active geodynamic processes in subduction zones. Full article

(1) Background: Geothermal resources are enriched in Jiangsu Province, particularly in its mid-deep geothermal reservoirs. The thermal properties and thermal effects of magmatic rocks, which are largely unknown in Jiangsu Province, are fundamental for analyzing the genetic mechanisms of geothermal resources and evaluating resource potential. (2) Methods: Representative magmatic rock samples from different geological periods and different tectonic settings are collected from the main tectonic units of Jiangsu Province. Key thermophysical parameters such as thermal conductivity, heat production rate, rock density, and porosity are systematically tested. (3) Results: The variation patterns of these thermal property parameters are analyzed, and the sources and spatiotemporal evolution characteristics of radiogenic heat production, and the thermal effects of magmatic rocks, are specifically explored. (4) Conclusions: Magmatic rock lithology from acidic to basic is negatively correlated with thermal conductivity, thermal diffusivity, and radiogenic heat production rate, and positively correlated with volumetric heat capacity. The radiogenic heat production of magmatic rocks is primarily controlled by the contents of U and Th, increasing with the increasing SiO₂ content. The formation of geothermal anomalies in areas with thin or absent sedimentary cover is significantly influenced by the thermal effect of magmatic rocks, especially by the high heat-producing granites. The radioactive thermal contribution of the Taolin and Suzhou plutons was calculated. Full article

Soft and weak rocks present challenges for construction activities in various environments. Their genetic origin, geological and tectonic evolution, and exposure to atmospheric conditions control their weathering and degradation over time. Therefore, a sound characterization of the associated rock parameters is essential. Numerous tests have been developed and standardized or defined in recommendations to assess various geomechanical, petrological, and mineralogical parameters. However, these tests are still subject to modification or extension to address project-specific issues. Additionally, standardized tests do not consider regional climatic conditions that may affect weathering, meaning they do not reflect the degradation behavior that is observed in the field. The present study investigates the slaking resistance and degradability of a range of soft rocks. The workflow of widely used tests is employed to evaluate their representativeness for different rock types in practical applications. Depending on their genetic origin and mineral composition, fabric alterations affect the rate and style of rock disintegration differently. Soft sedimentary rocks react already to static slaking, i.e., water immersion, whereas crystalline and grain-bound rocks slake under dynamic action while undergoing attrition in a rotating slake durability drum. Zones of structural weakness, such as foliation planes, are responsible for material removal in the latter; sedimentary rocks, on the other hand, are subject to surface particle separation (suspension) and suction due to the presence of clay minerals. This study presents an approach that combines the results of several routine tests to help identify and refine the slaking susceptibility of different rock types. A routine for inspecting and documenting the evaluated slaking characteristics for infrastructure maintenance is proposed, and the wider implications in light of climate change are discussed. Some limitations of the transferability of laboratory values to field sites still have to be evaluated and validated in the future. Full article

In this study, we develop a 3D thermal model of the South China Sea (SCS) lithosphere through the joint analysis of heat flow, Curie-point depth derived from magnetic anomalies, and shear wave velocity. Results show the Moho temperature is below 250 °C in the oceanic basin but exceeds 350 °C in continental margins. We evaluate potential Moho drilling sites based on temperature, crustal thickness, water depth, and sediment thickness, identifying six favorable zones in the east sub-basin. The thermal lithosphere thickness correlates with tectonic settings in continental areas, while the oceanic lithosphere is thicker than predicted by theoretical models. Global analysis suggests that the slow spreading rate may have also contributed to the thickening of the oceanic lithosphere in the SCS. Full article

The Late Holocene flood history of the Cauvery River floodplain in the Poompuhar region was reconstructed using a multiproxy sedimentological approach applied to three trench cores. Lithostratigraphy, loss on ignition (LOI), magnetic susceptibility (MS), sand–silt–clay textural analysis, granulometric statistics (Folk and Ward), Passega CM diagrams, and grain angularity provide complementary evidence to differentiate high-energy flood deposits from background slackwater sediments. Grain-size processing and statistical analyses were carried out in R using the G2Sd package, ensuring reproducible quantification of mean size, sorting, skewness, kurtosis, and transport signatures. We identified 10 discrete high-energy event beds. These layers are characterised by >80% sand content, low LOI (<3.5%), and low frequency-dependent MS (χfd% < 2%), confirming rapid, mineral-dominated deposition. A tentative chronology, projected from the regional aggradation rate, suggests two major flood clusters: a maximum-magnitude event at ~3.2 ka and a synchronous cluster at ~1.6–1.8 ka. These events chronologically align with the documented phases of channel avulsion in the adjacent Palar River Basin, supporting the existence of a synchronised Late Holocene climato-tectonic regime across coastal Tamil Nadu. This hydrological evidence supports the hypothesis that recurrent high-magnitude flooding triggered catastrophic channel avulsion of the Cauvery distributary, leading to the fluvial abandonment and decline of the ancient port city of Poompuhar. Securing an absolute chronology requires advanced K-feldspar post-IR IRSL dating to overcome quartz saturation issues in fluvial deposits. Full article