Search Results (30)

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

Reclaimed coastal areas are highly susceptible to uneven subsidence caused by the consolidation of soft marine deposits, which can induce differential settlement, structural deterioration, and systemic risks to urban infrastructure. Further, engineering activities, such as construction and loadings, exacerbate subsidence, impacting infrastructure stability. Therefore, monitoring the integrity and vulnerability of linear urban infrastructure after construction on reclaimed land is critical for understanding settlement dynamics, ensuring safe and reliable operation and minimizing cascading hazards. Subsequently, in the present study, to monitor deformation of the linear infrastructure constructed over decades-old reclaimed land in Mokpo city, South Korea (where 70% of urban and port infrastructure is built on reclaimed land), we analyzed 79 Sentinel-1A SLC ascending-orbit datasets (2017–2023) using the Persistent Scatterer Interferometry (PSInSAR) technique to quantify vertical land motion (VLM). Results reveal settlement rates ranging from −12.36 to 4.44 mm/year, with an average of −1.50 mm/year across 1869 persistent scatterers located along major roads and railways. To interpret the underlying causes of this deformation, Casagrande plasticity analysis of subsurface materials revealed that deep marine clays beneath the reclaimed zones have low permeability and high compressibility, leading to slow pore-pressure dissipation and prolonged consolidation under sustained loading. This geotechnical behavior accounts for the persistent and spatially variable subsidence observed through PSInSAR. Spatial pattern analysis using Anselin Local Moran’s I further identified statistically significant clusters and outliers of VLM, delineating critical infrastructure segments where concentrated settlement poses heightened risks to transportation stability. A hyperbolic settlement model was also applied to anticipate nonlinear consolidation trends at vulnerable sites, predicting persistent subsidence through 2030. Proxy-based validation, integrating long-term groundwater variations, lithostratigraphy, effective shear-wave velocity (V_s³⁰), and geomorphological conditions, exhibited the reliability of the InSAR-derived deformation fields. The findings highlight that Mokpo’s decades-old reclamation fills remain geotechnically unstable, highlighting the urgent need for proactive monitoring, targeted soil improvement, structural reinforcement, and integrated InSAR-GNSS monitoring frameworks to ensure the structural integrity of road and railway infrastructure and to support sustainable urban development in reclaimed coastal cities worldwide. Full article

The Caucasian Sea was among the vast tropical water masses that existed on Earth in the Mesozoic. The knowledge of Kimmeridgian–Hauterivian deposits from the central Western Caucasus can facilitate the understanding of the Caucasian paleogeography at the Jurassic–Cretaceous transition. Taking into account the scale of the study area and its geological complexity, a generalized synthesis of the published information seems to be an appropriate option to propose a tentative paleogeographical model. Some original field and laboratory studies, including the examination of the composition of Hauterivian alluvial sandstones, contribute to this model. Kimmeridgian–Hauterivian deposits crop out in the northern, western, and southern domains of the study area, but older rocks are exposed in its central and eastern parts. The Caucasian Sea covered the study area in the early Kimmeridgian, but a large land appeared in the late Kimmeridgian and existed until the end of the Hauterivian despite certain shoreline shifts. The land was eroded deeply, with exposure of pre-Upper Jurassic rocks, including Precambrian–Paleozoic crystalline complexes, and the sedimentary material was delivered to an alluvial plain on its periphery. The registered sea–land interplay was controlled tectonically. Full article

Urban expansion in coastal areas involves infrastructure development, industrial growth, and mining activities. These coastal environments face various environmental and geological hazards that require geo-engineers to devise solutions. An integrated geophysical approach aims to address such complex challenges as sea level rise, sea water intrusion, shoreline erosion, landslides and previous anthropogenic activity in coastal settings. In this study, the proposed methodology involves the systematic application of geophysical methods (FDEM, 3D GPR, 3D ERT, seismic), starting with a broad-scale survey and then proceeding to a localized exploration, in order to identify lithostratigraphy, bedrock depth, sea water intrusion and detect anthropogenic buried features. The critical aspect is to leverage the unique strengths and limitations of each method within the coastal environment, so as to derive valuable insights for survey design (extension and orientation of measurements) and data interpretation. The coastal zone of Throrikos valley, Attica, Greece, serves as the test site of our geophysical investigation methodology. The planning of the geophysical survey included three phases: The application of frequency-domain electromagnetic (FDEM) and 3D ground penetrating radar (GPR) methods followed by a 3D electrical resistivity tomography (ERT) survey and finally, using the seismic refraction tomography (SRT) and multichannel analysis of surface waves (MASW). The FDEM method confirmed the geomorphological study findings by revealing the paleo-coastline, superficial layers of coarse material deposits and sea water preferential flow due to the presence of anthropogenic buried features. Subsequently, the 3D GPR survey was able to offer greater detail in detecting the remains of an old marble pier inland and top layer relief of coarse material deposits. The 3D ERT measurements, deployed in a U-shaped grid, successfully identified the anthropogenic feature, mapped sea water intrusion, and revealed possible impermeable formation connected to the bedrock. ERT results cannot clearly discriminate between limestone or deposits, as sea water intrusion lowers resistivity values in both formations. Finally, SRT, in combination with MASW, clearly resolves this dilemma identifying the lithostratigraphy and bedrock top relief. The findings provide critical input for engineering decisions related to foundation planning, construction feasibility, and preservation of coastal infrastructure. The methodology supports risk-informed design and sustainable development in areas with both natural and cultural heritage sensitivity. The applied approach aims to provide a complete information package to the modern engineer when faced with specific challenges in coastal settings. Full article

The Placerias quarry is a dicynodont-dominated bonebed in Upper Triassic Chinle Group strata near St. Johns in east-central Arizona, USA. Though long identified as being in strata of the lower Chinle Group, recently published numerical ages apparently indicate a stratigraphically much higher (younger) position in the Chinle section for the Placerias quarry. Nevertheless, recent analysis of outcrop and subsurface (hydrologic) data in the vicinity of the Placerias quarry confirms its stratigraphic position very low in the Chinle Group section, close to the base of the Bluewater Creek Formation. A regional Upper Triassic lithostratigraphy has been established across east-central Arizona and west-central New Mexico by nearly a century of stratigraphic studies and geologic mapping by diverse workers, and is supported by biostratigraphy; in this lithostratigraphy the Placerias quarry is near the Chinle Group base. However, U/Pb ages on zircons from Upper Triassic strata in eastern Arizona/western New Mexico have been used to reorganize this lithostratigraphy to indicate intertonguing and dramatic lithofacies changes over relatively short lateral distances. But, if the well-established lithostratigraphy is followed, the U/Pb ages are problematic, particularly where younger ages (such as at the Placerias quarry) are stratigraphically below older ages. A handful of numerical ages should not be used to over-rule well-established understanding of lithostratigraphy and biostratigraphy, unless the lithostratigraphy and biostratigraphy need to be modified based on stratigraphic data. Numerical ages need to be used judiciously and evaluated critically with regard to established lithostratigraphy, biostratigraphy and other age constraints. Full article

Geotechnical slope failures—often precursors to catastrophic landslides and collapses—pose significant risks to mining operations and regional socioeconomic stability. Focusing on the Jiangte Xikeng lithium open-pit mine, this study integrates field reconnaissance, laboratory testing, and multi-physics numerical modeling to elucidate the mechanisms governing slope stability. Geological surveys and core analyses reveal a predominantly granite lithostratigraphy, bisected by two principal fault systems: the NE-striking F01 and the NNE-oriented F02. Advanced three-dimensional finite element simulations—accounting for gravitational loading, hydrogeological processes, dynamic blasting stresses, and extreme rainfall events—demonstrate that strain localizes at slope crests, with maximum displacements reaching 195.7 mm under blasting conditions. They indicate that differentiated slope angles of 42° for intact granite versus 27° for fractured zones are required for optimal stability, and that the integration of fault-controlled instability criteria, a coupled hydro-mechanical-blasting interaction model, and zonal design protocols for heterogeneous rock masses provides both operational guidelines for hazard mitigation and theoretical insights into excavation-induced slope deformations in complex metallogenic environments. Full article

The Kashmir Valley, characterized by its rich loess–palaeosol sequences (LPSs), provides a unique geo-archive for reconstructing Late Quaternary climate dynamics. This study presents an extensive multi-proxy study, integrating high-resolution lithostratigraphy, geochemical analyses, stable isotope analysis of soil organic matter (δ¹³C-VPDB), and radiocarbon (¹⁴C) chronology of a sediment sequence approximately 200 cm thick, to unravel the complex interplay of climatic, pedogenic and environmental processes shaping the region spanning the Pleistocene–Holocene transition. The results establish a precise chronology of the sediment sequence between 13.4 ka and 7.2 ka, covering the transition from the Pleistocene to the Holocene Epoch. The results reveal distinct climatic and environmental conditions during this Epoch. The study reveals substantial loess deposition during the cold and dry glacial climate towards the end of the Pleistocene, followed by a shift to a warmer and wetter interglacial climate at the onset of the Holocene Epoch. This climatic shift led to the development of soil units with pronounced fluvial characteristics around 10 ka, eventually transitioning to fluvial deposition. Geochemical indices such as Ca/Ti, Al/Ti, Si/Ti, and K/Ti indicate low weathering intensity prior to 11 ka, followed by a noticeable increase around 11 ka, possibly driven by enhanced precipitation. δ¹³C values, ranging from −26.2‰ to −22.5‰, suggest C₃-dominated vegetation during the Late Pleistocene, indicating wetter climatic conditions. This study provides valuable insights into the intricate interactions between climate, soil development, and vegetation dynamics during the critical Late Pleistocene–Holocene transition in the Kashmir Valley. Full article

The southwestern region of China is tectonically situated within the Tethyan tectonic domain, with the eastern part comprising the Upper Yangtze Block, while the western orogenic belt forms the main part of the Tibetan Plateau. This belt was formed by the subduction of the Paleo-Tethys Ocean and subsequent arc-continent collision, and was later further modified by the India-Asia collision, resulting in complex geological structures such as the Hengduan Mountains. The lithostratigraphy in this region can be divided into six independent units. In terms of mineralization, the area encompasses two first-order metallogenic domains: the Tethyan-Himalayan and the Circum-Pacific. This study synthesizes extensive previous research to systematically investigate representative rare earth element (REE) deposits (e.g., Muchuan and Maoniuping in Sichuan; the Xinhua deposit in Guizhou; the Lincang deposit in Yunnan). Through comparative analysis of regional tectonic-metallogenic settings, we demonstrate that REE distribution in Southwest China is fundamentally controlled by Tethyan tectonic evolution: sedimentary-weathered types dominate in the east, while orogenic magmatism-related types prevail in the west. These findings reveal critical metallogenic patterns, establishing a foundation for cross-regional resource assessment and exploration targeting. The region hosts 32 identified REE occurrences, predominantly light REE (LREE)-enriched, genetically classified as endogenic, exogenic, and metamorphic deposit types. Metallogenic epochs include Precambrian, Paleozoic, and Mesozoic-Cenozoic periods, with the latter being most REE-relevant. Six prospective exploration areas are delineated: Mianning-Dechang, Weining-Zhijin, Long’an, Simao Adebo, Shuiqiao, and the eastern Yunnan-western Guizhou sedimentary-type district. Notably, the discovery of paleo-weathering crust-sedimentary-clay type REE deposits in eastern Yunnan-western Guizhou significantly expands regional exploration potential, opening new avenues for future resource development. Full article

Landslides are one of the most serious problems affecting large parts of the world. There are two approaches that are used to study the organization of these land cover features: firstly, an approach utilizing lithostratigraphic tools, where soils are described and interpreted in accordance with specific geological/lithological patterns, and, secondly, through pedological instruments, where the pedogenetic patterns are identified, and the sequences are identified via standardized criteria and organized according to modern classification systems. In the present review, a comparison between the two above approaches is outlined, using the Campania Apennine reliefs (Southern Italy) as the reference environment because they are periodically and dramatically affected by mass movements mainly associated with rainfall events. These reliefs are strongly influenced by the products emitted by the Phlegraean Fields and the Somma–Vesuvius volcanoes. These products affect surface structures either through their direct alteration, with the formation of pedogenized products, or through their reworking, mainly stimulated by rainfall events, which is also responsible for the movement of pedogenized materials along the slopes. This results in complex surface architectures, knowledge of which is a crucial step in the assessment of robust monitoring systems. This review covers the Cervinara area, located in the central portion of the Campania Apennines, which was overwhelmed by dramatic landslide events in 1999. Our aims were to critically analyze the impact and the potential of lithostratigraphic and pedological approaches in studying the soils of the area in question and to provide an inventory of the scientific papers in which, with different aims, descriptions and interpretations of the local soil covers are reported. We examined and selected the national and international literature available in major scientific online databases, and these were split into groups on the basis of citations and type of approach. The reviewed literature showed that the stratigraphic approach was by far the most preferred, although significant potential was offered by pedological tools in this field of investigation. A high number of hydraulic and geotechnical articles was also found, in comparison to geological and pedological papers, which confirmed the significant levels of interest in the land cover type in question, specifically regarding landslide processes, and in their role in risk mitigation practices. On the whole, the latter approach has been proven to offer a greater exploration potential through the use of rigorous classification systems and, thus, the possibility of identifying and correlating soil properties over large areas. Full article

The purpose of this study was to enhance the understanding and sustainable groundwater management of volcanic aquifer systems by estimating key hydrogeological parameters. The transmissivity of a volcanic aquifer system was estimated using analytical solutions based on 68 constant rate and recovery data sets collected from various sources. A combination of hydro-lithostratigraphy and diagnostic plots was employed to identify the aquifer types and flow conditions, which facilitated model selection. Transmissivity of the confined aquifer was modeled using both Theis and Cooper–Jacob methods, with the Theis residual drawdown solution utilized for estimation. For the unconfined aquifer, the Neuman method was used, and the Hantush/Jacob method was employed for leaky aquifers. The results showed that the transmissivity of the Tertiary basalt varied from 0.38 m²/d to 860 m²/d, while the Quaternary aquifer system ranged from 2.33 m²/d to 1.8 × 10⁴ m²/d, indicating an increase in transmissivity with younger volcanic flows. Specific capacity (SC) was estimated for 74 wells and the values ranged from 0.62 to 5860 m²/d. This wide variation of specific capacity and transmissivity showed significant heterogeneity within the volcanic aquifers. This study introduces the innovative application of derivative diagnostic plots in groundwater research, offering an efficient approach for analyzing and interpreting pumping test data to characterize aquifer systems in various hydrogeologic units. This study focuses on aquifer characterization in hard rock formation, demonstrating methods that can be applied to similar geological environments globally. For the Blue Nile basin in general and for the Lake Tana basin in particular, the study result of aquifer characterization will contribute to exploration, development, and improved groundwater management in the region. Full article

We studied the Jafnayn Formation’s lithostratigraphy, microfacies, depositional environment, and uncertain presence of the Paleocene/Eocene boundary and present the first detailed analysis of a 127-m-thick section using the standard microfacies (SMF)/facies zone (FZ) system. The formation is dominated by foraminiferal grainstones and packstones of SMF 18-FOR, followed by peloidal grainstones and packstones of SMF 16. Coral-red algae floatstones of SMF 8 occur sporadically. SMF 18-DASY appears only once. SMF 16 and 18-FOR suggest a restricted lagoon, whereas SMF 8 and 18-DASY reflect episodic open marine lagoonal conditions. The section consists of four lithostratigraphic units. Considerable detrital quartz near the base (Unit 1: 22%; sand, sandstone, conglomerate) and top (Unit 4: 40%; sand) coincides with a restricted lagoon affected by near-shore processes (base) and near-shore conditions (top). Open marine conditions show an elevated bioclast diversity in units 3 and 4. Unit 2 displays very thickly-bedded limestones of the restricted lagoon. The lagoon barriers likely consist of foraminifera and other allochems that were reworked from the lagoon to form shoals. Coral remains in units 3 and 4 suggest that coral build-ups in the upper part of the formation protected the lagoon as well. The early Eocene age of several basal Alveolina species in the lowermost 9 m of the studied section indicates that the section is incomplete, with the late Paleocene part and meters-thick basal yellow marl missing. The Paleocene/Eocene boundary is unexposed. Full article

Greece is expanding its energy grid system with submarine power and fiber optic cables between the mainland and the Aegean Sea islands. Additionally, pipelines have been installed to support natural gas facilities, and sites are being demarcated for the development of offshore wind parks. The above developments have necessitated extensive geotechnical surveying of the seabed; however, the survey data cannot be accessed for academic inspection or for desktop studies of future developments. This is further hindered by the limited geotechnical information in the Aegean and Ionian Seas. This review examines the existing information concerning the geotechnical behavior of the surficial sedimentary layers, including certain challenges associated with geotechnical sampling and CPTu interpretation. Certain prospects are discussed regarding marine geotechnical research in Greece, with examples from other European countries. The marine geotechnical data in Greece include geotechnical analyses of sediments cores and slope stability estimations, which are commonly associated with the seismic profiling of unstable slope areas. Underlying mechanisms of slope failure have mainly been attributed to the interbedded presence of weak layers (e.g., sapropels, tephra and underconsolidated sediments), the presence of gas and the cyclic loading from earthquake activity. Due to the limited geotechnical information, geological studies have contributed considerably to describing the distributions of gravity-induced events and lithostratigraphy. Within this context, a geological/geotechnical database is suggested where data can be collated and utilized for future studies. Full article

The contribution of sediment transport and accumulation to soil formation was investigated in an area characterized by continental sedimentary activity since the Late Pleistocene. The area was the north-eastern portion of the large Quaternary graben represented by the Campania Plain, which is rimmed to the north–east–south by the Mesozoic carbonate Apennine nappes. The plain was filled mainly by products generated by eruptions from the Phlegrean Fields, which were also distributed on the slopes bordering the plain and remobilized toward the adjacent surfaces. Five sites were selected in the area in question. They were studied using morphological features and pertinent characteristics of the mineral soil fraction >2.0 mm, such as their volume and lithological description. Soils were compared to selected lithostratigraphic sequences characterizing the studied area, which were collected from literature and reinterpreted in pedological keys. The results showed that soils derived from the emplacement of Phlegrean primary volcanic materials, such as Campania Ignimbrite (~39–40 ky B.P.) and Neapolitan Yellow Tuff (~15 ky B.P.), with the related weathering products, and from volcanic materials reworked and transported by alluvial/colluvial episodes. The latter formed contrasting soil horizons which, differing in both rock fragment content and lithological composition, testified to the presence of lithological discontinuities. The formation of the horizons in question interrupted the genetic sequence derived from the in situ alteration of the volcanic substrata, suggesting that processes of transport and redistribution of sediments from the adjacent mountain slopes contributed to soil formation. The comparison of the pedostratigraphies with the lithostratigraphic sequences indicated a strong relation between geomorphic and pedogenetic events. Full article

In a pilot study, hyperspectral image analysis was applied to four boreholes from the North Midlands Block in Ireland. The selected holes are extremely well characterised lithologically and have a detailed micropalaeontology accurately constraining stratigraphic positions. Hyperspectral facies were defined using features extracted from the hyperspectral data and compared with existing litho- and biostratigraphic logs and samples. These were able to distinguish changes in the lithologies of the cores and were useful for defining unbiased lithological contacts and for regional correlations. Full article

El Olivo Cave (Pruvia de Arriba, Llanera, Asturias, Spain) is a small karst cave located in the Aboño River basin and formed in the Cretaceous limestone of the Mesozoic cover of the Cantabrian Mountains (north of the Iberian Peninsula). It contains an important upper Pleistocene sedimentary, archaeological, and paleontological record, with abundant technological evidence and faunal remains. The archaeological record shows a first occupation that could correspond to the Middle Paleolithic and a second occupation in the Middle Magdalenian. The stratigraphic sequence inside and outside the cave was studied with geoarchaeological methodology. In this paper, the lithostratigraphic sequence is analyzed, and the data from the granulometric, mineralogical, edaphological, and radiometric analyses are presented. The results of these analyses enable an accurate interpretation of both the lithostratigraphy of the deposit and the processes responsible for its formation and subsequent evolution. The available numerical dates allow us to locate the first sedimentation episode in the cave in OIS 7a, in the Middle Pleistocene, the base of the outer fluvial sedimentation in the cold OIS 3a stage of the Upper Pleistocene and the Magdalenian occupation in the Last Glacial Maximum (OIS 2) at the end of the Late Pleistocene. Full article