Deposition System Research Articles

Detrital-zircon U-Pb and (U-Th)/He double-dating provenance signatures in the Jaca foreland basin: interplay of direct vs. recycled sources during Pyrenean orogenic growth

ABSTRACT The Eocene to Miocene clastic wedge of the south Pyrenean basin constitutes a reference model to understand the progressive evolution of sediment provenance and source-to-sink dynamics in a foreland basin. We present new detrital-zircon (DZ) U-Pb and U-Pb-He (ZHe) double-dating data from the Jaca basin and the Ebro basin, providing insights into the evolution of the sedimentary systems that record a major tectonic and drainage reorganization from the late Eocene to Miocene. Three distinct DZ U-Pb signatures have been identified: i) Variscan dominated, ii) mixed Cadomian–Variscan, iii) Cadomian dominated, and two DZ ZHe signatures: i) Pyrenean dominated, ii) pre-Pyrenean dominated. Coupling DZ U-Pb, ZHe, and petrographic data allows us to discriminate among distinct Pyrenean sources as well as to understand how DZ signatures are propagated in a source-to-sink system. Our results indicate that while the eastern Jaca basin was fed from eastern source areas located in the central and eastern Pyrenees, the western Jaca basin was fed from the Basque massifs and the Urbasa–Andía Sierra (Basque–Cantabrian Pyrenees).

Neoproterozoic transition from subduction to breakup along the margin of the Rodinia supercontinent: Sedimentary evidence from the northwestern Tarim Block, Northwest China

The Tarim Block, northwest China, was positioned on the periphery of Rodinia during the Neoproterozoic Era, and preserves a geological archive chronicling the assembly and breakup of the supercontinent. Due to its antiquity and limited exposure, sedimentary records along the margin of the Rodinia supercontinent remain sparsely documented. This study focuses on the Xifangshan and Dongqiaoenbrak formations, the oldest sedimentary units in the northwestern Tarim Block, which comprise a Neoproterozoic sedimentary record at the supercontinent margin during the transition from subduction to breakup. A comprehensive analysis employing sedimentology, petrology, elemental geochemistry, and UPb detrital zircon chronology was undertaken, to elucidate paleoenvironment, parent rocks, and tectonic-sedimentary evolution. Findings show that the Neoproterozoic witnessed the subduction of an oceanic plate beneath the Tarim Block, resulting in the formation of a continental margin magmatic arc. The Xifangshan Formation, deposited during the late phase of this arc (with the earliest sedimentary age recorded at 770 Ma), represents a submarine fan dominated by turbidity currents. Around 760 Ma, rapid crustal uplift occurred, and the tectonic setting gradually shifted from subduction to rift, giving rise to the coastal alluvial fan sedimentary system observed in the Dongqiaoenbrak Formation. Both the Xifangshan and Dongqiaoenbrak Formations record deposition in an oxic to suboxic marine environment with moderate salinity, influenced by a semiarid to semihumid palaeoclimate. The continental margin arc served as the primary source for sedimentation in both formations, and a few magmatic products linked to extension (syenite, monzonite) were also cannibalized into the sedimentary system of Dongqiaoenbrak Formation. This transition from a turbidite system to a coastal alluvial fan represents a sedimentary response to the subduction-to-breakup dynamics along the margin of the Rodinia supercontinent.

Evolution mechanism of microbial community structure and metabolic activity in aquatic nutrient-poor sedimentary environments driven by 17β-estradiol pollution.

17β-Estradiol (E2) is a novel micro-pollutant that is widely distributed in aquatic sediments and has a universal toxicological effect on aquatic organisms. However, its ecological impact on aquatic microorganisms is not yet clear. In this study, we designed a simulation system for oligotrophic water deposition in the laboratory, analyzed the impact of different concentrations of E2 pollution on the carbon metabolism activity (carbon gas emission rate) of water microorganisms. Based on high-throughput sequencing results, we revealed the impact of E2 pollution on the community structure succession and metabolic function of bacteria, archaea, and methanogens in the simulated system, explored the impact mechanism of E2 pollution on microbial carbon metabolism in water bodies. Our results suggested that E2 significantly impacts the bacterial and archaeal community rather than the methanogen community, thereby indirectly inhibiting methane production. The achievements will bridge the theoretical gap between estrogen metabolism and carbon metabolism in sedimentary environments and contribute to enriching the ecological toxicology theory of steroid estrogen.

High-resolution organic and black carbon records in the South Yellow Sea over the last century

The mud depositional area ("mud area") of the South Yellow Sea serves as a prominent carbon sink within the Eastern Continental Shelf of China, offering crucial insights into human activities and climate fluctuations and its relationship with carbon cycle. This study investigates variations in total organic carbon (TOC) and black carbon (BC) concentrations in South Yellow Sea sediments. By combining 210Pb isotope analysis with grain-size profiling, the study distinguishes organic carbon origins, revealing the complex interplay between human activities and environmental shifts since the Industrial Revolution. The reasons for discrepancies between TOC and BC contents are analyzed, yielding the following results: (1) Sediment core QY-2 predominantly contains terrestrial-sourced organic carbon, primarily derived from the Yellow River and the Yangtze River. (2) Temporal fluctuations of BC in core QY-2 show distinct trends, periodic responses to human activities, particularly peaks in 1937 and 1945, linked to large-scale wars in China. (3) Relaxed carbon emission regulations in China, coupled with industrial growth spurred by the “reform and opening up” policy, led to a continuous rise in BC content from the mid-1960s to the 1980s, peaking in 1980. Subsequently, reduced BC values during the 1990s correlated with emission control policies and the shift from highly polluting domestic coal stoves to cleaner alternatives like liquefied petroleum gas or natural gas stoves. (4) BC content was influenced by the East Asian monsoon and Pacific Decadal Oscillation (PDO), with higher BC accumulation rates occurring in summer and depletion in winter. (5) Interestingly, changes in BC and TOC content exhibited a negative correlation. While grain size and material sources minimally influenced these discrepancies, the primary driver lay in the water's redox environment, impacting other TOC components and thereby causing variations in both TOC and BC content. This study of black carbon sources to sinks in the South Yellow Sea Mud Area holds significant implications for the broader Yellow Sea sedimentary system and provides support for understanding carbon cycle and marine environments.

Simulation and Experimental Verification of Pipeline Particle Deposition Based on Ellipsoidal Assumption

The problem of particle clogging in a conveying pipeline in thin-phase pneumatic transportation is essentially the effect of the particle-deposition mechanism in gas–solid two-phase flow. This paper presents a particle-deposition model of gas–solid two-phase flow based on the ellipsoid hypothesis, and a fast-calculation method of material particle-deposition efficiency in industry based on the tabular-assigned drag-correction coefficient of the particle ellipsoid-shape parameter Ar and incoming flow angle ϕ. A simulation comparison of spherical particles under the same pneumatic transport conditions and experimental verification based on the self-built particle deposition system are given. The validity of the model and the accuracy of the algorithm are verified. This provides a feasible simulation and experimental scheme for the research of pneumatic-conveying technology in the industrial field.

Early-stage intracontinental rifting in the Neoproterozoic Centralian Superbasin: Systematic U–Pb and Lu–Hf isotopes in detrital and inherited zircons from the Yeneena Basin, northwest Australia

Detrital zircons from different lithostratigraphic units of Supersequence 1 across the Neoproterozoic northwest Officer and Yeneena basins were investigated using LA-ICPMS U−Pb and Lu − Hf isotope analyses to understand the source of detritus and potential links to regional tectono-magmatic events, as well as the crustal evolution of the sedimentary sources terranes. All data show that Proterozoic detritus dominate the age spectra of samples from the Yeneena Basin and northwest Officer Basin, with signatures varying in the heights of peaks rather than the presence or absence of age groups in different formations. The Archean and Proterozoic ages overlap with known magmatic events in the Pilbara Craton, Fortescue Basin, Rudall Province, Capricorn Orogen, Musgrave Province, Madura Province, and the Coompana Province suggesting these terranes are possible sources of the detritus. The detrital zircon population of the samples have main age peaks in the range 1300 to 1000 Ma, suggesting magmatic rocks of the Rudall and Musgrave provinces are the main sources of detrital zircons, which can be differentiated by Hf signature. The distal Musgrave Province persistently dominates the provenance of detritus in the northwestern Officer and Yeneena basins, while detritus from the proximal Rudall Province contributes to a lesser extent. This suggests that the distal Musgrave Province remained emergent during the evolution of the northwestern Officer Basin and the Yeneena Basin, whereas the proximal Rudall Province potentially became buried by the accumulating sedimentary rocks and contributed less detrital zircons. The 833.6 ± 1.4 Ma maximum depositional age obtained in this study for the sedimentary rocks of the northwestern Officer and Yeneena basins point to the approximate time of the start of basins development. The extensional event in this age period is related to emplacement and extrusion of the ca. 830 Ma Willouran Large Igneous Province (LIP). The Duke gabbro sills observed in the Yeneena Basin are part of this LIP, which extends from the Adelaide Rift Complex, through the Musgrave Province, central–northwest Officer Basin and into the Yeneena Basin. The sediment source terranes suggest a southeast–northwest oriented depositional system between central and Western Australia, possibly because of intracontinental rifting related to widespread mafic–ultramafic magmatic events that could include the earlier Ngaanyatjarra Rift formed by the 1090–1040 Ma Warakurna LIP as well as the ca. 830 Ma Willouran LIP, synchronous with the breakup of Rodinia in the mid-Neoproterozoic.

Potentially toxic elements of lake and wetland in Northeastern Qinghai-Tibet Plateau: Distribution, potential sources and risk assessment

The accumulation of toxic elements from sediments poses imminent threats to both the environment and humans. The variation of elements in different sedimentary systems within the same watershed is of significant importance for distinguishing the human activities and adopting relevant management strategies. Based on the surface sediment samples from the Lake Keluke and its wetland, the content and grain size of elements were analyzed. The human health risk indicated in the area the potentially toxic elements (PTEs: Cr, Cu, Zn, Cd and Pb) were at no non-carcinogenic risk to adults or children. Except for Cd, the pollution levels of other PTEs were clean, and potential ecological risk with a low level. However, the pollution of Cd implicated a moderate to heavy pollution intensity and a high ecological risk. According to principal component analysis (PCA), and self-organizing maps (SOM), the main sources of PTEs were of the weathering and leaching of bedrocks; transportation and human agriculture activities. The watershed should reduce pollution caused by human activities and implement efficient agricultural practices.

Salinity reconstruction in Proterozoic depositional systems

Salinity reconstruction in Proterozoic depositional systems

Prediction of tight sandstone reservoirs by multiwave joint prestack inversion technology: A case study of the Qiulin area in the Sichuan Basin

The Shaximiao (SXM) Formation of the Middle Triassic in the central Sichuan Basin is a river-lake sedimentary system with an average burial depth of 2800 m. The channel sand bodies of the SXM Formation in the Qiulin area are developed with large lateral variation and high- and medium-porosity sand. This leads to great differences in the seismic response and difficulty in predicting the sand bodies and reservoirs using P-wave data. We carry out well-log analysis for different types of sand bodies. The no. 8 sand body of high porosity can be effectively identified using P-wave impedance (PI). Whereas for the no. 7 sand body of relatively lower porosity (mainly due to the higher shale content in the no. 7 sand compared with the no. 8 sand), sandstone and mudstone can be distinguished using S-wave impedance (SI), and reservoirs can be recognized by the P- to S-wave velocity ratio ([Formula: see text]/[Formula: see text]). Based on the PP wave and the P-to-S converted wave (PS wave) (after matching) angle-stacked data, a prestack inversion of multicomponent data is performed. Multiwave joint inversion results (SI and [Formula: see text]/[Formula: see text]) have better accuracy and stronger stability than the PP-wave inversion in practical application. In addition, the PI of the joint inversion more clearly describes the distribution and boundaries of the channel sand and better matches the prediction and drilling data in sand 8. The SI of the joint inversion can identify subtle sand bodies (weak PI contrast) that are difficult to be detected by PP-wave inversion. The distribution of the reservoir predicted by the [Formula: see text]/[Formula: see text] of the joint inversion is clearer (the no. 7 sand body) and better than that by the PP-wave inversion. This study demonstrates the advantage of the multiwave joint inversion technology in tight sand identification.

Multiproxy faunal analysis of the middle – upper Eocene deposits in the Fayum area, Egypt: Insights into sequence stratigraphy, trophic conditions, and oxygenation

The Eocene epoch experienced significant fluctuations in climate, ranging from intense greenhouse warming to icehouse cooling, which profoundly impacted the global depositional systems. The middle – upper Eocene deposits in Garet Gehannam, Fayum area, Egypt, present an exciting opportunity to explore paleoenvironmental dynamics using a multiproxy dataset of calcareous nannofossils, benthic foraminifera, ostracods, and molluscan assemblages. Calcareous nannofossil biostratigraphy constrained the studied sequence to the NP17 and NP-19-20 zones. Furthermore, three 3rd-order depositional sequences, BAR.SQ.1, BAR.SQ.2, and PR.SQ.3 were identified. The BAR.SQ.1 sequence encompasses the Gehannam Formation, with a transgressive systems tract (TST) and a highstand systems tract (HST). The BAR.SQ.2 sequence corresponds to the lower Birket Qarun Formation and exhibits a TST/HST pattern. The PR.SQ.3 sequence, however, consists solely of a TST spanning the upper Birket Qarun and Qasr El Sagha formations. The main trend of our multiproxy-based sea level curve shows an overall stepped Tethyan sea level regression within the 2nd-order cycle. This regression is characterized by a transition from outer neritic to inner settings, interrupted by two minor 3rd-order transgressive pulses. This sea level trend was likely driven by global eustatic changes and regional tectonic uplift related to the final collisional phase between Africa/Arabia and Eurasia, which led to the closure of the Neotethys Ocean. Multiproxy faunal analysis reveals a pronounced upsection shift from low-oxic and mesotrophic conditions to well-ventilated, oligotrophic settings tracking long-term sea level fall. The lowering of the sea level may have expanded aerobic ventilation windows on the continental shelf while potentially reducing nutrient influx. Our multiproxy sequence stratigraphic and paleoenvironmental analysis provides insights into the complex interplay of tectonic, eustatic, and climatic influences on the region during the middle – late Eocene episode along the southern Tethyan margin.

Contourite-drift archive links Late Devonian bioevents with periodic anoxic shelf water cascading

Analysis of a Devonian contourite depositional system in the eastern Anti-Atlas of Morocco reveals the formation of widespread erosional hiatuses and organic-rich bioclastic contourites (ORCs) coinciding with the expansion of an anoxic water mass during Frasnian bioevents, ultimately culminating in the Kellwasser crisis (Frasnian-Famennian extinction event). The identified contourite terrace formed on the uppermost slope of the northern passive margin of Gondwana. Its inner part was bounded by an along-slope contourite channel and a small mounded drift at its downslope margin. Facies- and drift-scale contourite features evidence northwest-directed bottom currents driven by repeated overflows of dense, highly saline, anoxic water originating from the northern Gondwana Epicontinental Sea. These periodic overflows were channeled through the Ougarta trough, then deflected westward over the Tafilalt contourite terrace by the Coriolis force and cascaded downslope until reaching a density equilibrium level, probably forming an intermediate water mass. The cascading of dense, anoxic shelf water supports the photic-zone eutrophication (top-down) model proposed for the Kellwasser crisis and related Devonian anoxic events. We propose a direct link between the anoxic overflows and the Devonian evolutionary events.

Decoding the complex fluvial-lacustrine sedimentary interactions: Insights from the Neogene Guantao Formation in the Bohai Bay Basin and Modern Poyang Lake, China

Small-scale lake level variations lead to significant landward/basinward shifts in the depositional system, thereby facilitating the widespread development of fluvial-lacustrine interaction sedimentary systems. Such systems are commonly found in low-gradient shallow-water continental down-warped lacustrine basins, which are favorable for the formation of composite reservoir-caprock assemblages. Nevertheless, our understanding of the sedimentary stratigraphy of the Neogene Guantao Formation remains limited due to the complex and variable spatial and temporal associations between fluvial and lacustrine deposits. Integrated analysis of the geomorphology and stratigraphy of the modern Poyang Lake Basin and ancient Bohai Bay Basin (BBB) allows us to develop a process-based fluvial-lacustrine interaction model of shallow-water depositional system. Three physiographic zones are identified based on seasonal lake shoreline migration during a certain geological sequence unit, namely fluvial-dominated zone (FDZ), fluvial-lacustrine interaction zone (FLIZ) and lacustrine-dominated zone (LDZ), respectively. The FDZ is always above the maximum lake shoreline without affection by lake basin water body and is characterized by channelized dendritic pattern of distributary channels with positive rhythmic cycles. The FLIZ is a dynamic interaction region between the maximum lake shoreline and the lowest lake shoreline. Reticular distributary channels, delta front and prodelta/lake deposits vertically superimpose and dominate the system that is featured by complex sandbody, stacked positive and negative rhythms and strong water body segmentation. The LDZ, away from the fluvial effect, was identified below the lowest lake shoreline exhibiting polycentric sheet water body, dominated by lacustrine mudstone interspersed with thin sheet-like sandstone. These results shed light on the spatial and temporal sedimentary heterogeneity in such dynamic fluvial-lacustrine interaction systems. The proposed fluvial-lacustrine interaction model may serve as a valuable analogue for identifying sedimentary types and predicting sandstone reservoirs in similar shallow-water settings ranging from continental down-warped lacustrine basins to cratonic basins, and fault-depression basin gentle-slope belts.

The dominant influence of muddy bottom currents on organic-rich fine-grained sedimentary rocks: The lower Congo Basin, west Africa

The Madingo Formation in the Lower Congo Basin (LCB) of West Africa is a fine-grained strata, which is considered to be the most promising source interval during the drift stage. Despite the extensive studies of the internal sedimentary characteristics of the Lower Mading Formation (LMF), muddy bottom currents have not been previously identified in this area. Extensive seismic (2D and 3D data), wire - line measurements and cutting samples in the LCB offer a unique opportunity to study the influence of muddy bottom currents depositional system on organic matter, and related depositional environment of the region and its depositional model of organic rich fine-grained strata. This study aims to unravel the influence of muddy bottom currents on organic matter enrichment within the LMF and build a depositional model. In combination with drilling and thin sections analysis, the M-1 member suggests the initiation and cessation of muddy bottom currents. Utilizing 3D seismic data inversion techniques, geochemical analysis, and sedimentological assessment, we studied the effect of muddy bottom currents on organic matter enrichment from the perspectives of paleoproductivity, preservation conditions, terrigenous input, and total organic carbon (TOC) distribution. Results show that muddy bottom currents have a significant impact on the redistribution of shallow water shelf sediments. They promote the transportation of nutrients and organic matter to deep water shelves, improving paleoproductivity. Most notably, terrigenous input is a key factor affecting organic matter distribution, resulting in dilution effects in deep water shelf bottom current influence areas, but conducive to the preservation of deep organic matter in low-lying areas of shallow water shelf. Muddy bottom currents have a weaker influence on the preservation environment of deep water shelves, but they have a significant effect on redox indicators (eg. U/Th, Ni/Co, V/Cr). Specifically, they reduce the enrichment in particulate elements. We established the depositional models of organic-rich fine-grained sedimentary rocks for the M-1 and M-2 members in LCB. These insights not only provide practical depositional models for marine sources rocks in the LCB, but also improves the general understanding of marine organic matter accumulation in muddy bottom currents environments. Furthermore, they serve as a reference for the study of organic-rich fine-grained sedimentary rocks in similar basins.

Updating the Upper Cretaceous (Campanian) Two Medicine Formation of Montana: Lithostratigraphic revisions, new CA-ID-TIMS U-Pb ages, and a calibrated framework for dinosaur occurrences

The Campanian Two Medicine Formation of northwestern Montana, USA, is richly fossiliferous, and discoveries made within the unit over the past century have greatly advanced our appreciation of dinosaur paleobiology and evolution. Previously undifferentiated from a lithostratigraphic perspective, the formation is now subdivided into four new members that include (from base to top) (1) the Rock City Member, (2) the Shields Crossing Member, (3) the Hagans Crossing Member, and (4) the Flag Butte Member. These new formal units and their associated fossil occurrences are also now included in an age model founded on eight high-resolution chemical abrasion−isotope dilution−thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb ages. New age data confirm that the Two Medicine Formation accumulated during much of the Campanian, with deposition spanning ca. 82.4 Ma to 74.4 Ma. New age data further indicate that a major reorganization of depositional systems, marked by a shift from predominantly lacustrine to alluvial facies and accompanied by a dramatic increase in accommodation, transpired near the base of the new Flag Butte Member at ca. 76.3 Ma. This change in depositional regime correlates in age with the Judith River−Belly River discontinuity, which marks the contact between the McClelland Ferry and Coal Ridge Members in the Judith River Formation and coincides with the onset of the Bearpaw transgression in north-central Montana. The new lithostratigraphic and chronostratigraphic framework for the Two Medicine Formation serves to contextualize and calibrate the formation’s rich dinosaur fossil record, which can now be interrogated with increased clarity and precision. These results also provide ground truth for numerical models that explore the structure of the fossil record in relation to alluvial architecture and terrestrial sequence stratigraphy.

Drainage reorganization and alluvial architecture of endorheic basins: The Lower Cretaceous record of the Chubut Group in the Golfo San Jorge Basin (Patagonia, Argentina)

The size, shape, and organization of depositional systems in endorheic basins are controlled by the tectonic and climatic history of the sedimentary basin and its boundaries. We evaluate the changes in the alluvial architecture of the Matasiete (Aptian) and Castillo (Albian) formations of the Chubut Group (Cretaceous) in the endorheic Golfo San Jorge Basin (Patagonia, Argentina) analyzing a ∼150 km transect along the San Bernardo Fold Belt, subsurface data, and coeval fluvial successions of the Los Adobes Formation in the nearby Cañadón Asfalto Basin. The Aptian Matasiete Formation represents an externally-sourced, high-accommodation fluvial system with its headwaters in the current Cañadón Asfalto Basin, flowing toward the alkaline lake of the Pozo D-129 Formation through N–S oriented sedimentary corridors of tectonic origin. Low sinuosity, fixed channels with ribbon geometries (mean thickness 7.3 m, W/T ratio 14) are encased in red-colored floodplain fines, whereas stratigraphic intervals rich in resedimented tuffs contain braided rivers with W/T ratio up to 90. Deposition of the overlying Albian Castillo Formation occurred in a W-E elongated basin disconnected from the Cañadón Asfalto Basin, comprising aggradational, volcaniclastic floodplain deposits and smaller-scale fluvial channels of narrow-sheet geometries (mean thickness ∼ 3m, mean W/T ratio 45). The Castillo Formation shows spatial variation in fluvial styles and channel sizes, with intermittent to ephemeral rivers of small scale near the headwaters and seasonal, perennial rivers in downstream positions. Alluvial architecture changes between the Matasiete and Castillo formations reflect changes in the configuration of the basin boundaries, subsequent re-organization of the channel networks, and variable supply of volcaniclastic particles to drainage catchments of different hierarchy that evolved in areas with large variation of the preserved thickness. Comparable geomorphic scenarios in the Okavango Macrobasin show multiple base levels (lacustrine, ephemeral pans), several drainage catchments of variable orientation, scale, and behavior (perennial, intermittent to ephemeral), and exotic rivers adjacent to minor-scale courses.

Sedimentary Facies, Depositional Environment, and High-resolution Sequence Stratigraphy of Dernah Formation, N Cyrenaica Promontory, NE Libya

The depositional environment and high-order stratigraphic architecture of the Eocene Dernah Formation in N Cyrenaica Promontory, NE Libya, were interpreted through detailed sedimentary facies and sequence stratigraphic analyses of four measured sections located several kilometers apart. Five distinct lithofacies were delineated based on variations in lithology, grain composition, fossil content, texture, color, and stacking pattern. Dernah Formation mainly contains nummulitic limestone with a noticeable amount of Discocyclina and rare gastropods. The extraordinary presence of Nummulites indicates shallow-marine carbonate settings, perhaps a Nummulite bank environment, where the reworking of sediments by wave- or tide-induced currents and storms is high. Two complete fifth-order depositional sequences were defined. Each sequence was subdivided into a transgressive and a regressive hemicycle based on the vertical lithological variation and stacking pattern of facies. We conclude that each sequence may have formed as a result of a fifth-order sea-level cycle. This study reconstructs a three-dimensional model for the Nummulite bank environment in the Mediterranean region, which can serve as an analog for similar depositional systems elsewhere.

Paleogene-Neogene ring-shaped sedimentary system and reservoir characteristics in the Western depression of the Qaidam Basin

The Paleogene-Neogene strata in the Western Depression of the Qaidam Basin represent a primary focus for oil and gas exploration and development. Influenced by both terrigenous clastic influx and endogenic carbonate deposition, these strata exhibit significant variation in sedimentary systems and reservoir characteristics. This study comprehensively examines the depositional patterns and reservoir properties of the Paleogene-Neogene sequence across the inner, middle, and outer belts of the basin, employing core analysis, thin section petrography, and physical property assessment of reservoirs. Key findings include 1) The development of a concentric sedimentary system in the Western Depression during the Paleogene-Neogene period, characterized by increased carbonate mineral content and decreased clastic material from the periphery to the center of the basin. 2) Varied sedimentary facies associations across different zones, with the outer belt dominated by fan delta and braided river delta deposits, and the middle and inner belts characterized by near-shore shallow lacustrine carbonates and algal mat deposits, and offshore semi-to deep-lacustrine fine sediments, respectively. 3) The outer belt exhibits reservoirs with favorable physical properties and connectivity, while the inner and middle belts show high heterogeneity, indicating potential for lithological traps and shale oil exploration. These insights offer scientific guidance for further investigation into the depositional systems of lacustrine basins in the Western Depression of the Qaidam Basin and for identifying promising reservoirs.

Decapod crustacean diversity through time and space in a middle-upper Eocene carbonate-siliciclastic platform (southern Jaca Basin, Pyrenees, Spain)

The south-central margin of the Jaca Basin (South-central Pyrenees, Spain) offers well-exposed outcrops ideal for studying the distribution of decapod crustaceans across a mixed carbonate-siliciclastic depositional system during the middle-late Eocene (Bartonian-Priabonian). This study encompasses an area of 1000 km2, featuring environments from siliciclastic coastal plains and deltaic complexes to shallow carbonate and mixed platforms, including coral reefs, extending to prodelta/outer platform deeper conditions. Detailed sampling in four depositional sequences yielded 372 fossil decapod specimens from various lithofacies across 20 localities.Our analysis identifies 39 decapod species within 22 families and demonstrates ecological zonation of decapods in shallow to relatively deep environments. Diversity peaks in siliciclastic shallow proximal prodelta areas and carbonate bryozoan meadows. Species distribution between carbonate and siliciclastic facies is similar, though taxonomically distinct. Articulated specimens predominantly occur in shallow proximal and relatively deep distal siliciclastic areas, linked to sudden sediment input and high sedimentation rates. These findings elucidate the spatial and temporal distribution factors of decapod crustaceans during the middle-late Eocene, contributing to the broader understanding of palaeoecological patterns in mixed depositional systems.

Advancing Lithium-Ion Batteries' Electrochemical Performance: Ultrathin Alumina Coating on Li(Ni0.8Co0.1Mn0.1)O2 Cathode Materials.

Ni-rich Li(NixCoyMnz)O2 (x ≥ 0.8)-layered oxide materials are highly promising as cathode materials for high-energy-density lithium-ion batteries in electric and hybrid vehicles. However, their tendency to undergo side reactions with electrolytes and their structural instability during cyclic lithiation/delithiation impairs their electrochemical cycling performance, posing challenges for large-scale applications. This paper explores the application of an Al2O3 coating using an atomic layer deposition (ALD) system on Ni-enriched Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) cathode material. Characterization techniques, including X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, were used to assess the impact of alumina coating on the morphology and crystal structure of NCM811. The results confirmed that an ultrathin Al2O3 coating was achieved without altering the microstructure and lattice structure of NCM811. The alumina-coated NCM811 exhibited improved cycling stability and capacity retention in the voltage range of 2.8-4.5 V at a 1 C rate. Specifically, the capacity retention of the modified NCM811 was 5%, 9.11%, and 11.28% higher than the pristine material at operating voltages of 4.3, 4.4, and 4.5 V, respectively. This enhanced performance is attributed to reduced electrode-electrolyte interaction, leading to fewer side reactions and improved structural stability. Thus, NCM811@Al2O3 with this coating process emerges as a highly attractive candidate for high-capacity lithium-ion battery cathode materials.

Pace of heavy metal pollution in the anthropogenically altered and industrialized Nakdong River Estuary, South Korea: Implications for the Anthropocene

Estuaries, vital coastal ecosystems, face growing threats from industrialization. To understand the pace of sedimentary changes and heavy metal pollution at the anthropogenically altered and industrialized Nakdong River Estuary in South Korea, we used sediment coring to reconstruct environmental change. Estuarine dam construction in 1934 shifted the sedimentary system from sand to mud, coinciding with a post-1930s mercury increase due to coal burning. Mercury concentrations in other South Korean regions surged in the 1970s, indicating proximity to emission sources matters. However, most heavy metal levels (Cu, Cd, Zn, Ag) sharply rose in the 1960s and 1970s with regional industrialization. Modern heavy metal concentrations doubled pre-industrial levels, underscoring human activities as the primary driver of Nakdong Estuary environmental changes. This emphasizes the need for a balanced approach to development and environmental preservation.