The miniaturization of organisms during the Permian-Triassic mass extinction, as an ecological strategy in response to environmental devastation, has been widely recognized in diverse marine invertebrates. Previous studies on the extinction process and miniaturization of foraminifers in the Permian-Triassic interval have relied on the fossil record of the low-latitude Paleotethys or a global database, although data and materials from the high-latitude Neotethys region are still rare. To reveal the evolutionary patterns and spatial variability of foraminifers at different latitudes and paleogeographic contexts, here we investigated the fossil distribution and size variation of foraminifers in the Selong Section of southern Tibet, located in the mid-latitude Neotethys of the Southern Hemisphere during the Permian-Triassic transition. The results show that the foraminifer of the Selong Section experienced a two-pulsed extinction (total species extinction rate of 71%), consistent with the time in South China but with a lower magnitude of extinction. Meanwhile, the data show that foraminiferal test volume was significantly miniaturized following the first pulse of extinction event: the mean size of post-extinction foraminifer was only 15% of that in the pre-extinction, mainly reflected by the disappearance of large forms as well as occurrences of smaller survivors and originators. Combined with the South China record, size data from southern Tibet indicate that the miniaturization of foraminifera is synchronous in the Paleotethys and Neotethys but smaller in magnitude in the Neotethys. We propose that ocean anoxia and acidification may be the environmental pressures leading to local and global foraminiferal miniaturizations, along with global warming, which might play a dominant role.

Multiple episodes of Neoproterozoic glaciation, namely the Beiyixi, Altungol, Tereeken and Hankalchough glaciations, are recorded in the Kuruktag area of northeastern Tarim Craton, NW China. The Tereeken glaciation was previously correlated with the global Marinoan glaciation based on sedimentary and chemostratigraphic features recorded in the cap dolostone immediately overlying the glaciogenic diamictite, as well as less precise radiometric age constraints. In this study, we obtained chemical-abrasion isotope dilution isotope ratio mass spectrometry (CA-ID-IRMS) U-Pb age of 624.03 ± 0.10 Ma from zircons extracted from a tuff lava interbeded within the diamictite of the Tereeken Formation, which suggests an Early Ediacaran age for the Tereeken glaciation. Such newly discovered Early Ediacaran glaciation in the Tarim region could have induced the negative δ¹³C_carb excursions of 625–605 Ma by providing oxygen and other oxidants to invoke remineralization of a deep ocean dissolved organic carbon (DOC) reservoir.

Jurassic continental strata are widely distributed in the Changdu area of eastern Tibet, but very few dinosaur footprints have been reported. Abundant sauropod, ornithopod and theropod footprints preserved in the Wenda site have been found during the recent geological surveys. This is a novel assemblage of the Middle Jurassic dinosaur footprints. These footprint fossils provide a key insight into the members of dinosaur faunas, and the behavior of the trackmakers. Here, the newly discovery small theropod footprints, which are identified as Wildeichnus isp., are discussed. The analysis of two trackways suggest that these two trackmakers (with a hip height of approx. 35 cm, and a body length of approx. 1 m) were moving slowly, with an estimated speed of 0.82 and 0.57 m/s, respectively. It is unusual for small theropods to move so slowly, and the present study supports the view that Wildeichnus had a global distribution, but the trackmaker of Wildeichnus is not interpreted as a juvenile Grallator.

The Torbat-e-Heydariyeh andesitic rocks (THA) are part of the Cenozoic continental arc magmatic system of the northern branch of the Neotethys Ocean (NE Iran). Columnar jointing is the most significant feature of these rocks and they also show porphyritic, vitrophyric, and vitroglomeroporphyric textures. Plagioclase, clinopyroxene, ±orthopyroxene are the major mineral phases. The SHRIMP U-Pb zircon dating yielded an age of 41.00 ± 0.69 Ma for the rocks (Middle Eocene, Bartonian). Geochemically, they are of medium- to high-K calc-alkaline affinity. Primitive mantle-normalized diagrams exhibit enrichment in large ion lithophile elements (LILE), such as Cs and Rb, and also depleted in high field strength elements (HFSE) and heavy rare earth elements (HREE), with prominent negative anomalies of Ti, Nb, Y, and Yb, suggesting a tectonic setting of an active continental margin. The chondrite-normalized REE diagram displays enrichment of light rare earth elements (LREE; La_N/Yb_N = 5.37–6.66) and small negative Eu anomalies (Eu/Eu* of 0.69–0.78). Thorium enrichment implies the reaction between the mantle wedge and the melt of subducting oceanic slab, and/or subducting sediment. The role of subducted sediments along with subducted oceanic lithosphere is evident in these magmatic rocks using Ba/La versus Th/Nd and Ba/Th versus La_N/Sm_N diagrams. The ε_Nd(t) and (⁸⁷Sr/⁸⁶Sr)_i values vary between -0.1 to +0.2 and 0.704 89 to 0.705 01, respectively, and are compatible with parental melts from subduction of the lithospheric mantle. We suggest that the THA rocks were produced by the partial melting of the metasomatized lithospheric mantle, which corresponds to slab break-off of the northward subducted Neotethys oceanic slab in an extensional setting. The hot asthenospheric mantle upwelling triggered by the Neotethys slab break-off would severely heat the physically mixed mantle wedge peridotite and therefore caused partial melting to produce the Middle Eocene volcanic rocks in NE Iran.

Mineral mixing, a fundamental process during mantle convection, alters the chemical composition of mantle minerals. However, the impact of this process on the electrical conductivity of mineral assemblages remains poorly understood. We measured the electrical conductivity of three single-phase garnets and their corresponding mixtures at 1.5 GPa and varying temperatures using the impedance spectroscopy within frequency from 10^-1 to 10⁶ Hz. The electrical conductivity of dehydrated garnets is primarily controlled by their iron content, exhibiting an activation energy about 1.0 eV, indicative of small polaron conduction. The garnet mixture displays lower electrical conductivities and higher activation energies compared to their single-phase counterparts. This discrepancy of conductivity can be half order of magnitude at high temperatures (> 1 073 K), suggesting formation of resistive grain boundaries during the mixing process. In the mantle transition zones, grain boundary conductivity could exert a limited impact on the bulk conductivity of the interface between the stagnant slab and ambient mantle.

The boundary between cratonic and orogenic lithospheres is a significant seismogenic zones marked by intense lithospheric deformation. The Sichuan Craton (SCC), as a key tectonic block bordering eastern Tibetan Plateau, resists the eastward escape of plateau's crustal materials, resulting in the uplift of the Songpan-Ganzi Block (SGB) and crustal deformation of the Longmenshan tectonic belt (LMTB). To elucidate the compressional structures and deformational modes of the LMTB and SCC, it is essential to accurately determine the location and geometry of the SCC' western boundary. To investigate this issue, the lithospheric properties of the obducted SGB, underthrusting SCC, and LMTB were analyzed using various geophysical data, including seismic reflection profiles, magnetotellurics, aeromagnetics, gravity, and seismic tomography. The SGB crust is characterized by low magnetism, seismic velocity, resistivity and Bouguer gravity, whereas the SCC crust exhibits non-uniform high magnetism, seismic velocity, resistivity and Bouguer gravity. The LMTB, as the boundary between the SGB and SCC, exhibits geophysical characteristics similar to those of the SCC in the southern and central segments. The integration of these geophysical observations indicate that the SCC's western boundary is situated west of the Wenchuan-Maoxian fault zone in the southern and central segments, exhibiting distinct westward wedging and underthrusting. However, this boundary aligns with the Yingxiu-Beichuan fault in the northern segment, without significant underthrusting. The irregular geometry of the SCC's western boundary further elucidates the variation in structural deformation along the LMTB. By comparing crustal thickness and lithospheric strength between the SGB and SCC, this study posits that the differing crustal strength between tectonic blocks may control the irregular geometry of the SCC's western boundary.

The origin of highly-fractionated granite-pegmatite systems and their associated rare metal mineralization has been widely studied, but there is still ongoing debate. Prevailing hypotheses suggest that pegmatite formation and the associated rare metal mineralization are closely related to aqueous fluid processes. Lithium (Li) isotope analysis has been widely applied to trace granite-pegmatite evolution. This is because lithium is widely present in various minerals (e.g., mica, tourmaline) that record the melt and fluid compositions, and lithium isotopes are sensitive to magmatic-hydrothermal processes. We briefly review the methodology of Li isotope analyses, the mechanisms of Li isotopic fractionation, and, in particular, Li isotope fractionation in granite-pegmatite system based on Li isotope data we have collected and the latest developments in Li isotope geochemistry. With the development of analytical technology, high-precision measurement of the Li content and isotopic compositions have facilitated a series of scientific breakthroughs in understanding the magmatic-hydrothermal evolution of rare-element ore deposits. Li isotope analyses on bulk mineral separates have demonstrated their ability to trace various hydrothermal processes. In situ Li isotope analysis methods has been enhanced by the development of new, homogeneous mineral reference materials. In situ SIMS and LA-MC-ICP-MS Li isotope measurements on minerals (e.g., tourmaline) will likely become more important in studying the fluid-rock interactions in magmatic, metamorphic, and hydrothermal processes, as well as on pegmatite petrogenesis and rare-metal mineralization.

Lack of information regarding lithium (Li) crystal chemistry in numerous minerals, especially those containing trace amounts of Li (ranging from a few to tens of ppm), limits our understanding of Li isotopic fractionation in pegmatites. In this study, we examined the Li isotopic composition and Li content in various Li-poor (e.g., quartz or feldspar) together with Li-rich (sopdumene or lepidolite) mineral phases within granitic pegmatites. We compiled a comprehensive dataset, encompassing a broad spectrum of Li contents (ranging from a few to tens of thousands of ppm) and Li isotopic values (-8‰ to 41‰). The minerals exhibit distinct Li isotopic signatures. Specifically, elbaite and beryl show the highest values, while biotite displays a negative average. Compared to individual minerals, whole rocks demonstrate lower Li isotopic values, with pegmatites exhibiting the highest and non-granitic pegmatite wall rocks showing the lowest. Our study also uncovers a clear "Vˮ shape relationship between Li isotopic values and logarithm of Li contents, with different mineral groups occupying specific regions within this shape. Furthermore, a significant correlation was observed between average Li isotopic values and Li-O (OH, F) bond lengths in various minerals. These discoveries underscore the crucial role of crystal chemistry in shaping the Li isotopic behavior in pegmatites from a statistical perspective.

Magnetite from hydrothermal deposits may show compositional zoning with various mineral inclusions in response to the evolution of hydrothermal fluids. Magnetite from the Fenghuangshan Cu-Fe-Au skarn deposit (eastern China) is a common mineral formed in the earlier stage of skarnization. Magnetite grains have dark gray and light gray zones and contain diverse mineral inclusions. Dark gray zones have higher Si, Ca, Al, and Mg contents than light gray zones. The magnetite matrix from dark gray zones shows superstructure along the [0-11] zone axis in fast Fourier transform patterns, different from magnetite in light gray zones with normal structure. Three types of mineral inclusions are identified within magnetite: nano-, micron- and submicron-nanometer inclusions. Nanoinclusions hosted in dark gray zones are actinolite, diopside, and trace element-rich magnetite, and these are likely formed by growth entrapment during magnetite crystallization at the skarn stage. The chain-width order-disorder intergrowths of diopside nanoinclusion likely indicate fluctuating fluid compositions in a lattice scale. Submicron to nanometer inclusions at the boundary between dark gray and light gray zones are quartz, titanite, and Ti-rich magnetite, which were formed via a dissolution and reprecipitation process at the quartz-sulfide stage. Micron-inclusions randomly distributed in both dark and light gray zones include calcite, ankerite, quartz, and chlorite, and these were formed via penetration of fluids at the carbonate stage. Zoned magnetite was formed by fluid replacement, overgrowth, and fluid infilling. Our study highlights the importance of mineral inclusion assemblages, and textural and chemical zonation of magnetite in constraining fluid evolution.

As one of the most important constitutes of shales/mudstones, quartz has received increasing interests in the last decades, because productive shale gas successions are generally rich in quartz content. This study critically documents quartz types, silica source for quartz cementation and effect of quartz cementation on reservoir quality in the Lower Paleozoic shales, Middle Yangtze region, South China, including the Lower Cambrian Niutitang Formation and the Upper Ordovician–Lower Silurian Wufeng-Longmaxi formations. Our results suggest that high-resolution scanning electron microscopy combined with cathodoluminescene techniques are necessary for identifying quartz types in shales. Integrations of high-resolution imaging technique and detailed geochemical analysis are able to document silica source for quartz cementation and silica diagenetic processes. Six types of quartz can be identified in the Paleozoic shales, primarily including detrital quartz silt, siliceous skeletons, quartz overgrowth, microcrystalline quartz (matrix-dispersed microquartz and aggregated microquartz), silica nanospheres and fracture-filling quartz veins. Dissolution of siliceous skeletons provides the principal silica sources for authigenic quartz formation in the Paleozoic shales. Authigenic quartz has dual effects on porosity development. Quartz overgrowth definitely occupies interparticle pores and possibly squeeze spaces, whereas aggregated microquartz can form rigid framework that is favorable for generating and preserving intercrystalline pores and organic pores.

Permafrost regions of Qilian Mountains in China are rich in gas hydrate resources. Once greenhouse gases in deep frozen layer are released into the atmosphere during hydrate mining, a series of negative consequences occur. This study aims to evaluate the impact of hydrate thermal exploitation on regional permafrost and carbon budgets based on a multi-physical field coupling simulation. The results indicate that the permeability of the frozen soil is anisotropic, and the low permeability frozen layer can seal the methane gas in the natural state. Heat injection mining of hydrates causes the continuous melting of permafrost and the escape of methane gas, which transforms the regional permafrost from a carbon sink to a carbon source. A higher injection temperature concentrates the heat and causes uneven melting of the upper frozen layer, which provides a dominant channel for methane gas and results in increased methane emissions. However, dense heat injection wells cause more uniform melting of the lower permafrost layer, and the melting zone does not extend to the upper low permeability formation, which cannot provide advantageous channels for methane gas. Therefore, a reasonable and dense number of heat injection wells can reduce the risk of greenhouse gas emissions during hydrate exploitation.

Obayied sub-basin provides one-third of the annual natural gas production in the Egyptian Western Desert. The origin of the Obayied hydrocarbons are however poorly constrained. In this study, the molecular biomarkers of the Obayied hydrocarbon blend were studied to infer on their origin and generation mechanism. The API values are in the range of (41.3°–53.7°) reflecting post-mature hydrocarbons. The molecular biomarkers suggest a generation of Obayied crude from clay-rich fluvio-deltaic source rocks. Age- and maturity-relevant biomarkers (e.g., Ts/Tm trisnorhopanes and methylphenanthrene indices) reflect a successive expulsion of the Obayied crudes from mature Jurassic rocks (> 1%Ro). Biological markers correlate perfectly with those of the Jurassic Khatatba shale and coal extracts attesting. Additionally, the Obayied gases are wet, thermogenic and have been derived from a mature type Ⅲ kerogen (1.3%Ro–2%Ro). The studied gases display compositional characteristics of mixed coal- and oil-type gases, and were therefore derived via primary cracking of the Khatatba coal as well as secondary cracking of the light liquid crudes. The present study clarifies the controls on the geochemical processes responsible for the accumulation of liquid and gas hydrocarbon mix in the deep as well as shallow inverted rift basins of the north Western Desert, Egypt.

Nearly 1 100 fissures have formed on the Hebei Plain in China. Within the Yellow River-Qinghe River-Zhanghe River shallow buried paleochannel band on the plain, 93 ground fissures controlled by paleochannels have developed, of which the Wuyi-Fuping ground fissure is a typical paleochannel-controlled fissure located in Hengshui, Hebei Province, with a total length of 3 km, a dominant strike of NE78°, and nearly upright in the shallow layer. The surface damage observed in this fissure primarily manifests as beaded pits, and its activity shows distinct segmentation characteristics. On the trench profiles, the offset distance of shallow layers remains consistently around 20 cm within the depth range of 0 to -3 m. An evident flexure is observed in the strata at depths ranging from -4.5 to -7 m. The drilling profile reveals that there is an absence of dislocations in the deeper strata. Nonetheless, the shallow seismic physical profiles unveil the presence of underlying faults beneath the study area, underscoring the intricate formation process and genesis mechanism of the Wuyi-Fuping ground fissure. Firstly, the formation and evolution of the Qingling River's paleochannel were shaped by the actions of fault blocks and underlying faults. The interplay of the regional stress field, fault block movement, and fault activity played pivotal roles in driving the development of this paleochannel. Secondly, the paleochannel exerts a controlling influence on the development location and severity of the fissure. During pumping, the confined aquifer within the paleochannel undergoes water loss and compression, resulting in the formation of a surface subsidence funnel. When the tensile stress surpasses the soil's tensile strength at the funnel's edge, the soil fractures give rise to a ground fissure. Finally, large amounts of surface water generated by heavy rainfall and irrigation can cause existing hidden ground fissures to rupture, emerge, and expand. This paper provides a heretofore generally unknown example, promotes research on the mechanisms of paleochannel-controlled fissures, and has guiding significance for disaster prevention and reduction in this area.

More than 5 000 landslides or potential landslides have been triggered in the Three Gorges Reservoir (TGR) area since the impoundment in 2003. This study aims at investigating the reservoir-induced landslides spatiotemporal and size distribution and its influence factors in the TGR by taking 790 landslides as statistical samples. The landslides exhibit significant regional and sub-regional spatial differences, and numerous landslides occurred at the initial three impoundment stages and the corresponding 2–3 cycles of reservoir operations followed, but the landslide frequency decreased dramatically after 2010 from temporal perspective. The relationship between landslide development and topographical, geological as well as hydrological factors were analyzed qualitatively. The reservoir-induced landslides in TGR area exhibit self-organized criticality and the rollover is nearly 2.5 × 10⁴m², which could not be attributed to the missing data but the coupled influences imposed by affecting factors. Both the double Pareto and inverse gamma functions are more suitable than the power-law function to present the landslide size characteristics. In term of the fitting precious, the adaptability of the inverse gamma function is better if the landslide inventories are limited. The research results provide foundation for the landslide susceptibility maps and hazard risk assessment.

In this paper, we present an approach to generating probabilistic hazard maps for earthquake-induced landslides using the Newmark Displacement Model (NDM). This model takes the uncertainties associated with the slope properties (e.g., soil shear strengths, groundwater table location) into consideration, which is coupled with the hydrological model based on geomorphological, geological, geotechnical, seismological, and rainfall data. Uncertainties and fluctuations in the input parameters of the NDM are considered by treating these quantities as β-PERT distributions through Monte Carlo techniques, which allows probability value of the NDM to be cast into hazard maps. Additionally, incorporating Monte Carlo techniques can avoid using conservative input parameters in a deterministic approach to capture these uncertainties. Taking the 2017 Jiuzhaigou M_w6.5 Earthquake in Sichuan Province, Western China as an example, earthquake-induced landslides probability distribution map is generated with the most appropriate displacement threshold (λ=1 cm). Our results show good performances for realistic landslide hazard assessment, which can serve as a basis for providing a reference for the prediction of earthquake-induced landslide probability and rapid landslide hazard assessment after a strong earthquake.

Brittleness is of great significance for evaluating the mechanical properties of the slope rock in reservoir area and revealing the brittle failure mechanism of the rocks. Although a series of definitions of the brittleness and evaluation methods of brittleness index have been proposed, there is still lack of a widely recognized and remarkable standards in these aspects due to the differences in diagenetic process, depositional environment and mineral composition. The previous methods to quantitively estimate the rock brittleness based on energy balance analysis are summarized, which neglect multiple influencing factors of the rock brittleness, such as the weight of pre-peak or post-peak mechanical behaviors on the prediction performance of the brittleness index. Based on the typical curves about stress and strain, the relationships between the brittle failure behaviors and the energy evolutions are comprehensively analyzed, then a new method for assessing the brittleness is proposed. Based on pre-peak brittleness index to represent brittle property at pre-peak stage and post-peak brittleness index to determine brittle characteristic at post-peak stage, a new brittleness index is established by additive synthesis method in consideration of the weight of brittleness indexes before and after peak strength, and either of the two brittleness indexes can be punished or compensated by setting different parameter values. The results indicate that the proposed brittleness index can represent the brittle change laws for different rock types when α ≤ 0.5, β ≥ 0.5. When evaluating the brittleness of the slope rock in Three Gorges Reservoir (TGR) area, the results show that the rock brittleness in the slope affects the stability of the slope. Therefore, the novel evaluation method can provide reliable results, and the proposed brittleness index considering the energy evolution can be applied to assess the brittle property in the reservoir bank project.

Volcanic hazard zoning is an effective way to reduce and mitigate volcanic risks. Due to its frequent magmatic unrest and potential for catastrophic eruption, the Changbaishan-Tianchi Volcano is currently the focus of attention for volcanic disaster prevention in China. This study uses past eruption data obtained from geological surveys and geochronological studies, to construct simulations of tephra fall, pyroclastic flows, lava flows, and lahars. Several widely accepted numerical models were adopted to simulate each hazard at different eruption scales. Hazard zoning was then conducted, producing a comprehensive hazards map of the Changbaishan-Tianchi Volcano. The map identifies areas of high, medium, and low hazard, mostly at 0–15, 15–60, 60–100 km from the edifice. This work serves as the scientific basis for the authorities and general public in the areas around the Changbaishan-Tianchi Volcano in planning for future response, as well as provides a reference for hazard zoning in other areas potentially affected by volcanic hazards.

Fast water can cause extraordinary bedload transport. Of the record floods considered here, the Jul. 26, 2022 urban flash flood on the upper River des Peres, St. Louis, Missouri provides particularly well-constrained data on flow conditions associated with large block movement. Field measurements and a detailed lidar survey show that concrete slabs as large as 3.0 × 2.5 × 0.33 m³ were moved from the open channel to reside 215 to 450 m inside a 6.5 m-diameter drainage tunnel, some to become part of a 10-m long imbricated pile. Peak flows of 160 m³/s were recorded at a gauging station located only 1.6 km upstream of the tunnel entrance, which provides a good estimate of 4.2 m/s for the peak flow velocity in the tunnel. Available observational data and a new theoretical analysis show that the radius of large boulders that can be moved by flowing water is directly proportional to the velocity head.

This study describes the clay mineralogy of the Lower Cretaceous (Barremian) rocks of the Wessex Basin for paleoenvironmental interpretations. Seventy-four samples were subjected to optical microscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), and quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN^®) techniques. The results revealed an illite-dominated sedimentation in most sections of the basin, with kaolinite, chlorite, smectite and glauconite occurring in subordinate quantities. Inferred paleoclimatic conditions from the clay mineral trends indicates a warm and dry climate, with seasonal precipitation. Kaolinite to illite ratios indicate that more arid climate conditions were prevalent but brief periods of warm and humid conditions were also present. A strong positive correlation between chlorite and tourmaline indicates that excess chlorite may have been contributed from tourmaline-chlorite-schists in a tourmaline-dominated provenance. SEM confirms that most of the clay minerals are detrital in origin but authigenic kaolinite is also present as vermiform and mica-replacive kaolinite which formed during early diagenetic modification from flushing meteoric waters in warm humid climates. This study is significant because it demonstrates the importance of multi-proxy methods for understanding clay minerals within sedimentary basins for interpreting the paleoclimatic conditions of depositional systems.

The active deforming southeastern margin of the Tibetan Plateau has developed series of fault basins filled with fluvial-lacustrine sediment deposited by drainage systems during every stage of its uplifting, the records of Cenozoic sedimentary sequence and detrital provenance in these basins are often obscure, making the interpretation of the drainage reorganization quite difficult. This research discovered the earliest Late Cenozoic fluvial conglomerate in the Yuanmou Basin, one of the fault basins in SE Tibet, and named the conglomerate as 'the Yuanmou Gravel Layer (YMG)'. Clast petrography, morphology and paleocurrent directions of the YMG indicate that the conglomerate is the remain of a large paleo river traversing through the Yuanmou Basin from north to south. Detrital zircon U-Pb ages can imply the YMG has similar provenance areas with Anning, Dadu and Yalong rivers at age peaks of 175-275, 600-1 000, and 2 100-2 700 Ma, but the lack of the age peak of 30-100 Ma from Qiangtang Block implies that the paleo-river was not yet connected with the Jinsha River during the YMG's accumulation. The fluvial-lacustrine strata with gravel beds containing paleosimian fossils comparable to the YMG were deposited~7-11 Ma, further suggesting that the pre-formed south-flowing river was active during the Late Miocene.

Using historical topographic maps and aerospace remote sensing data since the 1930s, this study investigates the spatial and temporal evolution of Dongting Lake beach. The evolution characteristics of the beaches in different regions and the related formation mechanism were also analyzed. The results show that Dongting Lake beach expanded from 1 622.17 km² in 1938 to 1 962.28 km² in 2018. With the addition of 980.96 km² of reclaimed high bay beach, the beach area increased by 1 321.07 km². However, the change process fluctuated somewhat rather than continuously increased. Substantial expansion of the beach area occurred during 1938-1948 and 1958-1998, while slow contraction of the beach area occurred during 1948-1958 and 1998-2018. Dongting Lake beach was dominated by terrigenous debris, the sedimentary types included lacustrine deposits, river alluvial deposits, floodplain and main channel deposits, and river-lake interaction deposits. The rapid expansion occurred in the estuary delta of the east branch of the Ouchi River, which advanced 38.55 km from the estuary toward the lake over the past 90 years. The causes of the changes in the beach included beach reclamation, sediment changes, and lake sand mining. Seventy embankments (covering 2 057.77 km²) have been enclosed in the Dongting Lake area since 1930s, of which the high bay beach covered an area of 980.96 km². The amount of sediment deposited in Dongting Lake has reached 230 857 × 10⁴ m³ since 1950s, which is equivalent to an average deposition height of 0.85 m on the lake's bottom. The mining of lake sand caused the beach to shrink, and the proportion of the beach area decreased from 77.18% in 1998 to 72.60% in 2018. The results of this study provide objective data for protecting the lakeshore's ecosystem and biodiversity and supporting the ecological restoration and environmental protection of the Yangtze River Basin.

Several aquifers located in North-Central Mexico have natural arsenic (As) concentrations higher than those allowed by national and international regulations; these aquifers are usually located in fractured volcanic environments that interact with sedimentary basins and have a carbonate basement. In this study, an evaluation of As in volcanic and sedimentary rocks collected at 13 sampling sites along the Sierra de Codornices (Guanajuato State, Central Mexico) was carried out. These geologic materials are representative of the dominant hydrogeologic environment. The As content is disseminated in volcanic rocks and the highest contents were obtained in felsic rocks; this information served to identify the hydrogeochemical processes related to the mobilization and transport of arsenic in the aquifer. The mobilization of As is a product of the dissolution of volcanic glass, a process involved in the alkaline desorption that occurs on As-containing mineral surfaces and possibly by the dissolution/desorption of Fe minerals and some clays, all these processes may be accelerated by the geothermal characteristics of the groundwater in the study area.

Biological classification is the foundation of biology and paleontology, as it arranges all the organisms in a hierarchy that humans can easily follow and understand. It is further used to reconstruct the evolution of life. A biological classification system (BCS) that includes all the established fossil taxa would be both useful and challenging for uncovering the life history. Since fossil taxa were originally recorded in various published books and articles written by natural languages, the primary step is to organize all those taxa information in a manner that can be deciphered by a computer system. A Knowledge Graph (KG) is a formalized description framework of semantic knowledge, which represents and retrieves knowledge in a machine-understandable way, and therefore provides an eligible method to represent the BCS. In this paper, a model of the BCS KG including the ontology and fact layers is presented. To put it into practice, the ontology layer of the invertebrate fossil branches was manually developed, while the fact layer was automatically constructed by extracting information from 46 volumes of the Treatise of Invertebrate Paleontology series with the help of natural language processing technology. As a result, 27 348 taxa nodes spanning fourteen taxonomic ranks were extracted with high accuracy and high efficiency, and the invertebrate fossil branches of the BCS KG was thus installed. This study demonstrates that a properly designed KG model and its automatic construction with the help of natural language processing are reliable and efficient.