Development Of Deposits Research Articles

Metamodeling the deposition process in oil preprocessing to optimize heat exchanger cleaning: a deep neural network approach

The accumulation of deposits in heat exchangers during oil preprocessing, known as fouling, compromises thermal efficiency and increases maintenance and energy costs. This study aimed to develop effective strategies for managing these deposits to optimize heat exchanger operations. Metamodeling combined with Artificial Intelligence was employed, using machine learning models to process sequential data, which is crucial for understanding the evolution of deposits over time. Two machine learning models, Deep Neural Networks (DNN) and Long Short-Term Memory (LSTM), were trained and evaluated. The DNN achieved a Mean Squared Error (MSE) of 0.05345, outperforming the LSTM, which had an MSE of 0.8763. The results suggest that the DNN was more effective in predicting fouling, although both models showed signs of overfitting. Advanced monitoring technologies, such as IoT and remote sensing, as well as predictive maintenance, were found to be essential for improving operational efficiency and reducing costs, highlighting the importance of digitalization and automation in oil preprocessing.

Pollen morphology and fruit anatomy of the enigmatic monotypic genus Dicranocarpus (Coreopsideae, Asteraceae)

Dicranocarpus is a monotypic genus endemic to the Chihuahuan Desert with atypical attributes among species of tribe Coreopsideae. Phylogenetic position of Dicranocarpus parviflorus has been controversial. A molecular phylogeny showed that the taxon was closely related to Dahlia; however, further analyses with a wider sampling of Dahlia, also including Hidalgoa, identified the genus in a more distant clade. The objective of this study is to gather anatomical attributes from the cypselae as well as palynological characters along with macromorphology to determine whether Dicranocarpus shares characters with these genera in Coreopsideae. Our results show that although the pollen of D. parviflorus does not possess attributes that distinguish it from the rest of the tribe Coreopsideae, they were useful to confirm its membership in the tribe. The cypselae anatomy identified that D. parviflorus has characters of taxonomic value that differentiate this species from the rest of the Coreopsideae. The three most significant novel characters in Dicranocarpus were in the outer mesocarp, consisting of tracheoidal-like cells forming irregular rows up to 250 μm in length, an aerenchyma in the middle mesocarp, and the lack of phytomelanin and calcium oxalate crystals. Furthermore, the results of the phytomelanin patterns in the studied taxa highlight the need for further anatomical studies of the cypselae to fully understand the evolution of phytomelanin deposition in the tribe Coreopsideae and even in the Heliantheae Alliance. Macromorphological, palynological and anatomical attributes of the cypsela in Dicranocarpus were not shared with Dahlia. Moreover, the sexual condition of the disc and ray florets shared with Hidalgoa has evolved independently in lineages of Asteraceae.

Evolution and hydro-stratigraphy of the coastal aquifer in Garopaba/SC: Interpretation from georadar and tubular wells

This work analyzes the geological evolution of sedimentary deposits in the coastal aquifer of Garopaba, south Brazil, using ground penetrating radar (GPR) and data from tubular wells. The aquifer is localized in the coastal plain, where Quaternary lagoon-barrier environments are set between the Precambrian crystalline mountains and the sea. Over ten tubular wells are scattered in urbanized areas, which highlights the vulnerability of the unconfined, granular shallow aquifer. The results show that the aquifer has lithologic units of local scale. Tubular well data show the basal limit of the aquifer overlying clayey layers between 30 and 40 m deep and intercalation of sand layers up to the surface, mostly fine to very fine sand, with metric thickness, secondary lenses of clay and minor occurrence of gravel. The radarfacies interpretation shows fluvial-estuarine deposits as a local hydrostratigraphic unit, with lateral accretion bars filling a NE-axis paleochannel. The basal surface of the channel is interpreted as the sequence boundary surface of the lagoon-barrier systems III (upper Pleistocene) and IV (Holocene). The geological evolution of the aquifer is related to the upper Pleistocene marine regression (120–18 ka), that caused the aerial exposure of the continental shelf, and the development of complex drainage channels, which were superimposed during the Holocene transgression by lagoon-barrier IV deposits. After the post-glacial transgression, the lowering of the RSL to the current level promoted the silting of part of the lagoon system by continental sedimentation and aeolian deposits composing the surface.

Fluid evolution and genesis of the Shipenggou gold deposit in Central Jilin Province, China: Constraints from C–H–O and in–situ sulphur isotopes of pyrite and fluid inclusions

The origin and evolution of the Shipenggou gold deposit in the Shipenggou–Jiapigou–Jinchengdong (SJJ) gold belt in Jilin Province, Northeast China, remain poorly understood. In this study, fluid inclusion and C–H–O–S isotopes from the Shipenggou deposit were investigated to clarify the fluid evolution and mineralisation process. The gold mineralisation is hosted in the biotite plagiogneiss of the Archaean Sandaogou Formation and is dominated by gold–bearing quartz veins. The orebodies are controlled by NNE– and NEE–striking brittle–ductile structures. Four stages of mineralisation have been identified: (I) milky quartz–minor pyrite, (II) quartz–pyrite–minor gold, (III) gold–quartz–polymetallic sulphide, and (IV) quartz–carbonate. Fluid inclusions were identified as four types: aqueous (VL–type), CO2–bearing (CL–type), CO2–rich (LC–type), and carbonic (PC–type). VL–, CL–, LC–, and PC–type FIs were developed within quartz from Stages I–II. Stage III quartz contains both CL– and VL–type FIs. Only VL–type FIs were observed in calcite from Stage IV. The total homogenisation temperatures (Tht) of FIs in Stages I, II, III, and IV are of 281.5–324.8, 215.5–269.1, 151.2–198.3, and 125.4–149.5 °C with salinities of 2.8–13.2, 2.8–9.6, 3.2–8.4, and 3.0–5.9 wt% NaCl eqv. Laser Raman spectroscopy analysis indicated the CL– and PC–type FIs from Stages I and II contain CO2 and minor quantities of CH4. The ore–forming fluids have developed from a medium temperature, low–medium salinity immiscible NaCl–H2O–CO2 ± CH4 system to a low temperature, low salinity homogeneous NaCl–H2O system. The HO isotopic compositions indicate that the initial ore–forming fluids were mantle–derived magmatic water. Subsequently, the ore–forming fluids were gradually joined by meteoric water. δ13C values indicate C in the fluids have originated from organic matter. Organic matter may have originated from the mantle, which mixed crust materials influenced by the subduction of the Palaeo–Pacific slab. In–situ, S isotope data of pyrite indicate that the origin of sulphur at the Shipenggou deposit is the mantle containing a crust component. Based on the above analysis results, the Shipenggou gold deposit is a mesothermal magma-hydrothermal vein–type gold deposit.

Anatomy of the late Pennsylvanian to early Triassic failed rift system of the Cooper Basin, eastern Australia

The onshore intracratonic Cooper Basin of central Australia developed during the Late Pennsylvanian to Middle Triassic periods at paleolatitudes of approximately 50°S within the Gondwanan sector of the Pangea. Despite the wealth of data available, including the drilling of over 4,800 boreholes, there is limited knowledge about the Cooper Basin’s origins and evolution. To better understand the basin’s geological history, legacy data sets, including composite 2D seismic sections, well logs, measured sections, and 1D burial history models from the west of the basin, are integrated to reinterpret the basin’s tectonic and sedimentary evolution. Interpretation of the seismic sections and calculated subsidence rates indicates an earlier active rift phase with grabens and half-grabens that transitioned, in the latest Permian, into a regional sag phase. The evolution of tectonic styles heavily influenced the paleogeographic evolution of the basin fill and resulting depositional architecture. The basin sediments are entirely terrestrial in nature and facies reflect a transition from glacial environments in the late Pennsylvanian to warmer and drier conditions in the early Triassic. During much of the Permian the basin was underfilled and the relative low influx of fluvial sediment did not keep pace with creation of accommodation, allowing the development of extensive mire and lake systems. Coal beds are up to 30 m thick. By contrast, the basin appears to have been overfilled during the latest Permian to Triassic with rivers flowing along the central axis of the basin. The synchroneity of commencement of rifting, termination of rifting, and commencement of a sag phase within the failed rift systems of the Cooper Basin, the East Gondwana Interior Rift, and the East Australian Rift strongly suggests a continent-wide period of extension related to significant changes in plate motions during the Late Pennsylvanian to Middle Triassic.

Eolian-fluvial Succession in the Early Cretaceous from the Ordos Basin

Cretaceous eolian deposits are widely developed in North China, among which the Lower Cretaceous eolian (erg) sedimentary strata in the Ordos Basin are the most representative. Many studies have been conducted on eolian deposits in the Ordos Basin, especially the Luohe Formation; however, there is a lack of systematic sedimentology research and the corresponding research on the evolution of sedimentary facies. Therefore, to explore the Mesozoic drought events and the systematic evolution of the sub-tropical erg zone, this study reports the fluvial–eolian sedimentary sequences of the Early Cretaceous Luohe and Yijinhuoluo Formations in the Ordos Basin. Spatially, through detailed sedimentary lithofacies and structural analysis of different outcrops, the combination law of sedimentary facies can be determined. Based on this, a three-dimensional sedimentary model of erg is reconstructed. The erg environment is divided into three sub-environments: erg margin, erg margin–centre transition and erg centre. According to the evolution of the sedimentary facies, the sedimentary evolution from the Late Jurassic to the Early Cretaceous in the Ordos Basin is divided into five stages. The Ordos Basin has experienced the delta, erg formation, erg deposition, erg shrinkage and evaporating salt-lake stages. The vertical sedimentary evolution indicates climatic oscillation in North China from the Late Jurassic to the Early Cretaceous. Under the control of the sub-tropical high belt, the Ordos Basin experienced a hot and arid climate during the Cretaceous, forming a widely distributed erg belt in the region. During this period, a small-scale climate shock occurred under the hot and arid background, changing the sedimentary environment.

Ultrafast Laser Manipulation of In-Lattice Plasmonic Nanoparticles.

Plasmonic nanoparticles enable manipulation and enhancement of light fields at deep subwavelength scales, leading to structures and devices for diverse applications in optics. Despite hybrid plasmonic materials display remarkable optical properties due to interactions between components in nanoproximity, scalable production of plasmonic nanostructures within a single-crystalline matrix to achieve an ideal plasmon-crystal interface remains challenging. Here, a novel approach is presented to realize efficient manipulation of in-lattice plasmonic nanoparticles. Employing ultrafast-laser-driven plasmonic nanolithography, metallic nanoparticles with controllable morphology are precisely defined in the crystalline lattice of yttrium aluminum garnet (YAG) crystal. Through direct ion implantation, hybrid plasmonic material composed of nanoparticles embedded in a sub-surface amorphous YAG layer is created. Subsequently, femtosecond laser pulses guide formation and reshaping of plasmonic nanoparticles from the amorphous layer into the single-crystalline matrix along direction of light propagation, facilitated by a plasmon-mediated evolution of laser energy deposition. By tailoring resonance modes and optimizing the coupling between structured particle assemblies, a range of applications including polarization-dependent absorption and nonlinearity, controllable photoluminescence, and structural color generation is demonstrated. This research introduces a new approach for fabricating advanced optical materials featuring in-lattice plasmonic nanostructures, paving the way for the development of diverse functional photonic devices.

Paleogeographic reconstruction and sedimentary evolution of tidal-dominated estuarine depositional systems: Insights from the campanian M1 sandstone formation, Oriente Basin, Ecuador

The Oriente Basin is a back-arc basin located east of the Ecuadorian Andes in South America. Evidence suggests that during the Cretaceous period, the basin's margins received a terrigenous shallow marine sedimentation. Due to regional variations in accommodation and depositional controlling factors near a shoreline, the sedimentary environments in the fluvial-marine transitional zones exhibit considerable variability. In this study, we analyzed the sedimentological characteristics of the M1 Sandstone Formation unit (∼83 Ma-72 Ma), which comprises a set of ancient estuarine deposits preserved in the northern part of the basin. We quantified the impact of mixed hydrodynamic processes on the distribution of tidal-dominated estuarine facies and discussed the development conditions and evolutionary processes of an estuarine formation under the background of persistent transgression. Core, well log, and seismic data provide evidence for reconstructing the tidal-dominated estuarine environment. In the core section, we identified 14 lithofacies and 7 major facies association types. The frequent occurrence of sedimentary structures associated with tidal currents indicates that tidal processes extensively reworked the deposits. The spatial distribution trends of facies associations reveal the evolution of mixed hydrodynamic conditions dominated by tidal processes in the estuary and allow us to divide the M1 Sandstone Formation into four depositional periods: the initial development, rapid development, decline, and the post-infilling open coast tidal flat development periods. Furthermore, through a systematic analysis of hydrodynamic conditions and sediment distributions, we identified multiple depositional centers in the tidal-dominated estuary influenced by different hydrodynamic processes. These correspond to the upstream fluvial-dominated tidal point bar depositional region, the middle mixed-energy depositional interaction zone, and the downstream tidal-dominated tidal sand bar depositional region. In these regions, the substantial accumulation of sandy deposits, represented by tidal sand bars, reflects the high accommodation space characteristic of tidal-dominated estuaries. Our findings indicate that the slow subsidence of a broad and gently sloping coastal topography, stable material transport, and sea level change dominated by marine transgression ensured the necessary accommodation for the development of the estuary in the M1 Sandstone Formation. The sedimentological study of the M1 Sandstone Formation provides a case for understanding the sedimentary evolution in fluvial-marine transitional zones.

Hydrogeological Regions of Kolubarska Posavina (Central Serbia)

The groundwater catchments of the Kolubarska Posavina are of significant importance because if some contamination affects the groundwater system, it is necessary to find a quality groundwater source for the water supply of Obrenovac Municipality. Reconstruction of sedimentary evolution plays a significant role in the investigation of groundwater catchment. In this study, the variation in sedimentary characteristics and sedimentary evolution/paleogeography were studied for Quaternary catchment identification in Kolubarska Posavina. The groundwater catchment of the Kolubarska Posavina can distinguished into two main parts. The western part of Kolubarska Posavina is identified as the Sava groundwater catchment, where the Sava alluvial plain and the (paleo) meanders of the Sava are located. The east part belongs to the Kolubara groundwater catchment, characterized by the remnants of the (macro) alluvial fan of Kolubara and the Kolubara floodplain. The Kolubara catchment is located eastwards from the older meander of the Sava River.

Sequence stratigraphic architecture and depositional evolution of the early Eocene-early Miocene Al Jabal Al Akhdar carbonate successions, N Cyrenaica Promontory, NE Libya – Interplay of tectonics and eustasy

The interactions of tectonics and eustasy on the stratigraphic architectural evolution of the early Eocene-early Miocene Al Jabal Al Akhdar carbonate sedimentary successions were evaluated. This evaluation was achieved through detailed analyses of microfacies, depositional interpretation, and sequence stratigraphic framework of five measured sections located within the Al Jabal Al Akhdar Uplift, northeast Libya. The study interval was subdivided into distinct microfacies based on lithological changes, grain size and components, sedimentary texture and structures, fossil contents, color, and vertical stacking pattern. Six major depositional settings were delineated: restricted lagoon, open marine lagoon, platform margin and shoals, platform-margin reefs, foreslope, and middle to lower slope. Four third-order unconformity-bounded depositional sequences were identified based on vertical and lateral facies distribution, variations in fossil contents, and diagenetic features. Each sequence is composed of a transgressive-regressive interval, except for the younger sequence, which only contains a transgressive unit. Four evolutionary stages are recognized: initiation, growth, high-relief platform, and subaerial exposure. Subsidence resulting from tectonism and sediment loading, coupled with rising sea-level, created the accommodation space for the sedimentation of the studied carbonates. Repeated eustatic sea-level fluctuations controlled the internal stratigraphic heterogeneity and sequence development. Tectonic uplift caused a major sea-level retreat, resulting in the emersion of the carbonate sequences. The pre-existing Mesozoic and Paleocene sequences that underwent major uplift during the Late Cretaceous-early Eocene formed a shallow-water positive-antecedent topography for the formation of the carbonate sediments. This study establishes a carbonate sequence stratigraphic hierarchy of different cyclic sedimentation orders and improves our knowledge of sedimentary and stratigraphic architectural evolution and depositional mechanisms of carbonate platforms in an inverted basin setting. This knowledge can aid in predicting the distribution of lithofacies and depositional systems of economic importance.

Effect of heat input on ultrahard Fe-Cr-B-C-W-Mo-Nb hardfacing

Multicomponent alloys (Cr, Mo, W, Nb, C, B) nanostructured iron base with complex carboborides have been developed to provide great protection against abrasive wear to elements of agricultural and mining machines. These overlays are subject to severe material losses due to impact and abrasion of hard particles and therefore optimizing their wear resistance is critical when it comes to their lifespan, increasing it as a result. The objective of this work was to study the influence of heat input on the wear resistance through of the analysis of the solidification rate. In this sense, the increase of welding speed was produced a decrease of heat input and refined of microstructure. In order to explain these effects, an analysis was made of of the influence of welding speed on the geometry of the deposited metal, dilution with the base metal, microstructural evolution and hardness of iron-based nanostructured deposits with complex carbides. For this, four samples were welded with different speeds; these being 1, 2.5, 5 and 12 mm/s. A semi-automatic welding process was used with a 1.6 mm wire rope used to provide gas protection. The chemical composition was analyzed on a dilution free welded sample. For the each welded sample the dilution percentage was determined, the dimensional survey of the beads was carried out and the microstructure was characterized by X-ray diffraction and optical and scanning electron microscopy. In addition, Vickers microhardness tests were measured in the central area of the beads and the microhardness of phases were measured. The dilution of the deposited metals ranged from 17% to a maximum of 28%. A microstructure formed by a matrix with complex metal carbides and carboborides was observed. The hardness of the beads varied between 960 and 1350 HV2. The highest wear resistance was found in the sample with highest speed welding.

Genesis and fluid evolution of the Hatu orogenic gold deposit in the West Junggar, Western China

The West Junggar in Xinjiang, western China, represents a significant gold mineralization belt hosting over 200 gold deposits, with the Hatu gold deposit being the largest among them. In this study, ore geology and fluid inclusion assemblages of quartz samples from the Hatu gold deposit were investigated in an effort to clarify the mineralization process and its relationship with the geodynamic settings. The mineralization process is delineated into early (pyrite-albite-quartz veins), middle-a (quartz-ankerite veins), middle-b (quartz-ankerite-sulfide-native gold veins), and late (quartz-calcite veins) stages. The early stage veins suggest a compressional setting while the middle-a and middle-b stage veins suggest a tensional shear setting. The late stage veins are typically filled fissures cutting through earlier veins. Scanning electron microscope-cathodoluminescence (SEM-CL) reveals that early stage quartz (Q1) exhibits concentric CL-oscillatory growth zoning, while middle-a stage quartz (Q2a) displays unidirectional zoning and ranges from CL-bright to CL-dark, middle-b stage quartz (Q2b) is CL-bright and weakly zoned, and late-stage euhedral quartz (Q3) shows sector zoning transitioning from CL-gray to CL-dark. Quartz that formed in these stages developed three types of fluid inclusions: pure CO2 (PC-type), CO2–H2O (C-type), and H2O–NaCl (W-type). The early stage quartz contains C- and W-type fluid inclusions homogenizing at 309–345 °C, while the late stage quartz contains only W-type fluid inclusions with homogenization temperatures of 164–229 °C. Microthermometry of fluid inclusion indicated the evolutionary of the metallogenic fluid from a high-temperature, CO2-rich, and minor CH4 metamorphic fluid to a low-temperature, CO2-poor meteoric fluid. From the early to middle-a stages, fluid boiling caused the unloading of ore-forming elements whereas fluid mixing led to the precipitation of polymetallic sulfides and gold in the middle-b stage. Trapping pressures in the middle-b stage were estimated using C-type inclusions, illustrating that gold mineralization took placed at depth of 8.0 km. We propose classifying the Hatu gold deposit as an orogenic deposit, originating from the collisional orogenesis between the Yili-Kazakhstan and Siberian continents in the Late Carboniferous.

Reconstructing early sedimentation patterns of the lower Codó Formation (Early Cretaceous, NE Brazil): Evidence of marine influence and the onset of an alkaline hypersaline lake

The upper Aptian lower Codó Formation is an attractive stratigraphic unit within the Parnaíba and São Luís basins, northeastern Brazil, formed during the break-up of Western Gondwana. Located in a large sag basin, the formation records a dynamic depositional history of deltaic, lacustrine, and sabkha environments. This sedimentary evolution is reflected in a diverse lithological succession characterized by intermittent terrestrial input, episodic marine incursions, and restricted lacustrine phases culminating in sulfate evaporite precipitation. While the later stages of the formation have been extensively studied, the initial sedimentary processes and environmental conditions remain poorly understood. This research aims to reconstruct the depositional paleoenvironments during the initial stages of Codó sedimentation, elucidating the onset of the alkaline hypersaline lake environment and the earlier marine incursions in the study region. To achieve this, it was conducted a high-resolution facies analysis using core descriptions, trace fossil analysis, petrography, various types of X-ray fluorescence, scanning electron microscopy, X-ray diffractometry, and isotope analyses (δ1³C, δ1⁸O, and ⁸⁷Sr/⁸⁶Sr) on a ∼63-m-thick succession from borehole 2-TV-1-MA. Thirteen facies were recognized and grouped into brackish lake, prodelta, delta front, and alkaline hypersaline lake facies successions. The lower Codó Formation exhibits cyclic sedimentation, indicating fluctuating water dynamics associated with shifts between open and closed drainage systems controlled by paleoclimate. Tectonic subsidence drove the basin's evolution from a brackish lacustrine-deltaic environment with an incipient marine influence (balanced-fill basin stage) to a restricted system with the establishment of an alkaline hypersaline lake (underfilled basin stage).

The Psematismenos-Maroni Basin (South Cyprus): Cenozoic tectonic and sedimentary evolution

The Tertiary regressive sedimentary succession, which forms the sedimentary cover of the Troodos Ophiolitic Massif, was studied in the Psematismenos-Maroni Basin in Southern Cyprus. A series of unconformity surfaces were identified based on key surfaces, morphologies, and sedimentary facies. These observations are reinforced by numerous new biostratigraphic datings mainly based on calcareous nannofossil analysis. Unsuspected biostratigraphic hiatuses ranging from million to dozens of millions of years are illustrated. Some unconformity surfaces are tectonically enhanced leading to the emersion of this basin. In addition, our work highlights the importance of the Messinian Salinity Crisis in the shaping of an onshore erosion surface in Cyprus as it is the case in the Sorbas basin in the western Mediterranean. Constrained by new datings, this work finally proposes a tectono-stratigraphic calendar for the Psematismenos-Maroni Basin, starting from the Paleogene Lefkara Formation up to the first alluvial deposits at the end of the Neogene.

Multiple sources of elevation change during and after the 2011–2012 Cordón Caulle, Chile eruption measured by satellite topographic time series

The 2011–2012 eruption at Cordón Caulle, Chile offers an exceptional opportunity to investigate topographic evolution of a laccolith, lava flows, and tephra during and after rhyolitic eruptions using satellite TanDEM-X and Plèiades data. We find distinct phases: rapid surface uplift from the laccolith and tephra (June–August 2011) and lava (June 2011–March 2012), followed by a reduction in the elevation of the laccolith and tephra (up to 19 m yr−1) until February 2013, and slower subsidence of all deposits until 2019 (the most recent data). The spatial distribution of subsidence-to-uplift ratios shows different volcanic and geomorphological processes occurring (degassing, cooling, crystallization, lateral movement, compaction, erosion). Pre-eruptive river channels showed elevation increases of up to 10–50 m due to tephra deposition, but this tephra was largely removed within three to four years. This research shows the potential of repeating high-resolution remote sensing elevation data to elucidate volcanic landscape evolution and yields insights into the co- and post-eruptive evolution of deposits.

Millennial-scale sedimentary evolution of carbonate platforms during the Permian–Triassic boundary hyperthermal event

The millennial-scale response of shallow-water carbonate platforms to the climatic upheaval at the Permian–Triassic boundary (PTB) remains unclear. This study presents three carbonate platform sections across the Permian–Triassic (P–T) boundary in South China and the Lhasa terrane. A total of 14 types of carbonate microfacies were identified, which show that the Liangfengya and Taiping sections in South China were deposited in an inner ramp, and the Wenbudangsang section on the Lhasa terrane was deposited in an outer ramp. Bulk carbonate carbon isotope patterns through the sections are generally characterized by negative excursions (−2.2 to −3.5‰) during the PTB hyperthermal event. These excursions can be divided into four phases (NC1 to NC4), with NC1 before the negative carbon isotope excursion (NCIE) event, NC2 during the initiation phase of the NCIE, NC3 during the body of the NCIE, and the NC4 marking the recovery stage of the NCIE. The pattern of sedimentary changes in each section through the PTB hyperthermal event, and the relationship between these changes and the carbon isotope stages, was established. In the studied sections, the onset of the NCIEs (NC2 stage) preceded evidence for a carbonate production crisis, with the occurrence of anachronistic facies developed after this crisis but prior to the NC3 stage. In detail, our data show that the carbonate production crisis occurred 11 kyr after the onset of the NCIE, and 47 kyr before the first Permian–Triassic mass extinction (PTME), and that the carbonate production crisis may have been closely related to the environmental stresses associated with greenhouse gas emission from the Siberian Traps Large Igneous Province (STLIP).

Latest Pleistocene-Holocene sedimentary evolution from sediment records of the Tam Giang-Cau Hai coastal lagoon system, central Vietnam

The latest Pleistocene-Holocene sedimentary evolution was reconstructed from two boreholes collected in the Tam Giang-Cau Hai coastal lagoon region of central Vietnam. This research was based on analyzing radiocarbon dating, grain size, sedimentary structure, petrological components, and diatom assemblages. Besides, some high-resolution seismic data from the lagoon water body were interpreted to estimate Holocene sediment thickness. Sedimentary records of two boreholes revealed various sedimentary facies under the sea-level change since the Last Glacial Maximum (LGM): Fluvial channel facies, fluvial-lagoonal transition facies, lagoon facies, lagoonal-to-fluvial facies, and flood plain facies. Radiocarbon dating indicated that the coastal lagoon system possibly initiated around 8.8–8.5 cal kyr BP, corresponding to the meltwater pulse 1 C when saltwater intruded into the lagoon system. The borehole-sediment data combined with the high-resolution seismic data shows the thickness of Holocene sediments is approximately 20–35 m in the lagoon region. The study also suggested that the sandy barrier complex along the coast between the lagoon system and the open sea has been likely built during the transgression since 10–8.8 cal kyr BP. Additionally, five ecological zones were identified based on diatom assemblages in borehole HK02 indicating variations in marine and fluvial influence in the coastal lagoon system during the past 8.8 kyr: Dia-HK02–1 indicates a low presence of diatoms, suggesting a weak marine influence in the coastal lagoon system; Dia-HK02–02 shows the strongest marine influence and stable ecological conditions in the coastal lagoon system; Dia-HK02–03 demonstrates a partial decrease in marine influence; Dia-HK02–4 shows an increasing fluvial influence; and Dia-HK02–5 developed under completely dominated fluvial conditions on land.

Turbulence and sediment deposition in a channel with floating vegetation

Floating canopies of vegetation alter the vertical profile of flow velocity within and below canopies, which in turn impacts sediment deposition below canopies. This study explored the impacts of channel-average velocity (U0), vegetation density (a), and relative flow depth (hg/H, where hg is the height of the free flow region below the floating canopy and H is the entire flow depth) on the longitudinal distributions of near-bed turbulent kinetic energy (TKE) and sediment deposition in a channel with a floating vegetation canopy. Below a floating canopy, sediment deposition was correlated with the near-bed TKE. For the low-density and low-velocity cases, sediment deposition was spatially uniform across the entire channel because the near-bed TKE was lower than the critical value for sediment resuspension. As the vegetation density and channel-average velocity increased, the near-bed TKE increased and surpassed the critical TKE, which caused resuspension and reduced deposition below the canopy relative to the upstream reference. For the same vegetation density and channel-average velocity, a lower relative flow depth (hg/H) produced a higher below-canopy depth-averaged velocity and near-bed TKE, resulting in less deposition below the canopy. A model was proposed for predicting the longitudinal evolution of near-bed TKE based on the predicted flow velocity below the canopy throughout the channel. The longitudinal evolution of deposition below a floating canopy was predicted by combining the predicted near-bed TKE with the deposition probability. The predicted near-bed TKE and deposition matched laboratory measurements. Finally, the proposed model can be used to predict the longitudinal profile of deposition below a real Eichhornia crassipes canopy.

OSL and radiocarbon dating of core TBF-1 on the outer shelf of the East China Sea and implications for late Quaternary stratigraphic correlation

It is crucial to establish a robust chronology for understanding late Quaternary sedimentation processes and environment changes in response to sea-level fluctuation on shelves. The shelf of the East China Sea (ECS) is featured by huge terrigenous sediment input and striking land -sea interaction during the late Quaternary. However, there remains controversy in chronostratigraphic rebuilding of transgression and regression deposits during eustatic-glacial cycles, mainly due to a lack of reliable dating data. In this study, an extensive comparison of 17 optically stimulated luminescence (OSL) and 15 AMS 14C ages from core TBF-1 (upper 40 m) provides a constraint in chronostratigraphic reconstruction since Marine Isotope Stage (MIS) 5. OSL ages range from 9.5 ± 0.7 to 67.3 ± 4.8 ka at depths from 2.00 to 28.00 m, while 14C ages range from 6645 to 41435 cal a BP at depths from 0.02 to 17.52 m. Regression analysis demonstrates a high level of agreement between OSL and 14C ages, with r2 values of 0.91 and 0.90, respectively. For Holocene sediments (U1), both OSL and 14C methods are applicable in tidal sand ridges, however, it should be noted that 14C ages may exhibit a young bias of up to 3 ka. For pre-Holocene sediments (U6-U2), OSL ages are robust within saturation limitation of OSL signal (De up to ca. 166 Gy), cross-checked by feldspar post-IR IRSL (pIRIR) dating protocol. Nevertheless, the shell 14C ages (11620 and 10390 cal a BP at depths of 13.95–14.56 m) in Last Glacial Maximum (LGM) fluvial sediments of U2 are significantly underestimated, because of their susceptibility to recrystallization and overgrowth, resulting in carbon exchange with environment. While the peaty layer's14C age in deltaic deposition (17.50 m, U5) was determined to be 36420 cal a BP, coincided with OSL age of 39.6 ± 3.9 ka. The chronostratigraphy since MIS 5 for core TBF-1 exhibits a significant correlation with previously published cores SFK-1, DZQ4, and DH02, on the ECS outer shelf. Through the evaluation of those underestimated 14C ages and saturated OSL ages, we re-elucidated the primary sedimentary facies and their respective formation periods. This sedimentary stratigraphic illustration exhibits significant consistency with eustatic-glacial cycles. The renewed chronological framework for ECS shelf allows better correlation between the late Quaternary sedimentary evolution and the land-sea interaction on open shelves dominated by siliciclastic sedimentation.

Phase-Field Model of SEI Formation in Li-Metal Batteries

The formation of solid electrolyte interphase (SEI) is critical to the overall performance of lithium batteries. Here we have developed a rather comprehensive phase-field model for predicting the formation and growth of SEI, taking into account of multiple electrochemical/chemical reaction pathways leading to multiple SEI reaction products, diffusion of ionic and molecular species, and electron tunneling. All the SEI products are treated stoichiometric compounds without the typical approximation of parabolic composition dependence in almost all existing phase-field models involving stoichiometric compounds, allowing the direct connection between the phase-field model and atomistic calculations without further approximation. As a model system, we consider a 1-D prototypical half-cell with Li metal anode, liquid ethylene carbonate (EC) electrolyte with 1 molar (M) LiPF6, and SEI products Li2BDC and Li2CO3 under the open-circuit condition. The reduction potentials and activation barriers of the reactions are determined using atomistic simulations while the diffusivities of Li+ and EC in the bulk electrolyte are obtained by performing molecular dynamics simulations. The phase-field simulation is capable of predicting the evolution behavior of SEI products within a wide range of time scales from nanoseconds to a few seconds. It reveals that: (i) a porous Li2BDC layer forms at the anode/electrolyte interface and grows to a stable thickness of several tens of nanometers within ~20 μs; (ii) a porous Li2CO3 layer forms between anode and Li2BDC and grows to ~10 nm by partially consuming the existing Li2BDC layer within ~33 μs; and (iii) Li2CO3 forms a dense layer by filling the pores within ~20 ms. The stage (i) and (ii) are dominated by Li+ diffusion kinetics whereas stage (iii) is controlled by the reaction kinetics. The general computational framework can be extended and applied to the simultaneous evolution of Li-metal deposition and stripping and the SEI evolution.