Depressed Areas Research Articles

Detecting evolutionary stages of karst depressions in Central Brazil with deep learning and Planet NICFI time series

AbstractKarst depressions represent significant geomorphological features crucial in environmental monitoring and conservation. This research aims to detect and classify karst depressions according to their evolutionary stages in the Bambuí Group, located between the Cerrado and Caatinga biomes in Central Brazil, using Planet time series provided by Norway's International Climate and Forest Initiative (NICFI) Satellite Data Program and deep learning‐based semantic segmentation models. A new deep learning training dataset was developed containing manually labelled reference data and a time series of monthly images from Planet NICFI data over a year. The research classified three evolutionary stages of karst depressions: (1) temporary lakes, (2) depressions with concentric halos and subsidence and (3) vegetated depressions. These stages represent distinct geomorphological processes, from initial water accumulation to more advanced stages involving subsidence and vegetation development in the depression areas. The study compared six state‐of‐the‐art semantic segmentation architectures (U‐Net, U‐Net++, DeepLabV3+, LinkNet, FPN and PSPNet), each combined with three backbones (EfficientNet‐B7, ResNet‐101 and ResNeXt‐101), resulting in 18 model configurations. The best performing model (U‐Net with EfficientNet‐B7) achieved a mean Intersection over Union (mIoU) of 80 and IoU scores of 97.9 for the background, 80.93 for first stage, 79.89 for second stage and 63.35 for third stage, highlighting the challenges of detecting more advanced stages due to increasing vegetation cover and geomorphological complexity. The sliding window approach was employed to classify the entire image mosaic, testing various stride values (8, 16, 32, 64, 128 and 256), with smaller strides improving segmentation accuracy at the cost of higher computational demands. The results demonstrate the importance of integrating spectro‐spatio‐temporal data to detect multiple evolutionary stages and improve the robustness of semantic segmentation. This research provides a comprehensive dataset and benchmark for future studies on karst depressions, contributing to understanding geomorphological evolution and conservation planning in Central Brazil.

Amygdala-centered fusional connections characterized nonmotor symptoms in Parkinson's disease.

The importance of nonmotor symptoms in understanding the pathogenesis of the heterogeneity of Parkinson's disease has been highlighted. However, the validation of specific brain network biomarkers in nonmotor symptom subtypes is currently lacking. By performing a new approach to compute functional connectivity with structural prior using magnetic resonance imaging, the present study computed both functional connectivity and fusional connectivity features in the nonmotor symptom subtypes of Parkinson's disease, one characterized by cognitive impairment with late onset and the other depression with early onset. The functional connectivity and fusional connectivity features centered at the left amygdala were both detected. The fusional features significantly enhanced the classification performance. The amygdala-postcentral and amygdala-orbital frontal features were critical for cognitive impairment with late onset detection, while the amygdala-temporooccipital features were crucial for depression with early onset detection. Additionally, the fusional connectivity features between the amygdala and the junction sulcus of parietooccipital and temporooccipital regions contributed significantly to differentiating cognitive impairment with late onset and depression with early onset. The within-subtype correlation analysis revealed that age at onset and cognitive scores were associated with features of amygdala-somatosensory/visual-motor processing areas in cognitive impairment with late onset, while related to features of amygdala-emotional processing areas in depression with early onset. Our findings highlighted distinct amygdala-centered fusional connectivity features related to diverse nonmotor symptoms in Parkinson's disease, offering new insights for pathogenesis-targeted treatments for specific Parkinson's disease subtypes.

P0401 The IBD-disk accurately assesses disability and psychological burden at IBD diagnosis and predicts adverse outcomes in both UC and Crohn’s disease during the first year of treatment

Abstract Background Inflammatory bowel disease (IBD) is linked with increased prevalence of mental health diseases (MHD), particularly anxiety and depression. How this influences treatment outcomes is poorly studied at IBD diagnosis. The IBD disk is a patient-reported outcome measure that quantifies disease-associated disability. We aimed to determine if the disk can be used pre-diagnosis to screen for mental health symptoms and predict treatment outcomes. Methods Patients with suspected IBD were seen in a rapid-access clinic. An IBD disk was completed upon review, pre-diagnosis. A subgroup simultaneously completed the Hospital Anxiety and Depression scale (HADS). Repeat disks were completed after diagnosis, with 12-month outcomes collected prospectively. Results 188 patients completed a baseline disk (97 Crohn’s disease [CD], 91 Ulcerative colitis [UC]), 95 completed a simultaneous HADS and 82 completed a repeat disk. Both a pre-existing MHD diagnosis (CD 22%, UC 11%, X2 p=0.049) and an active anti-depressant prescription (CD 16%, UC 7%, X2 p=0.035) were more common at CD diagnosis than UC. The ‘Emotions’ domain correlated with HADS depression (rs=0.607 p<.001), anxiety (rs=0.586 p<.001) and reliably identified HADS defined moderate-severe depression (Area under the curve 0.873). A score ≥7 identified all patients meeting this HADS threshold (Sensitivity 100%, specificity 60.5%, Youden’s index 0.601). This is shown in Figure 1. Whilst the IBD Disk did not outperform traditional disease severity indices, elevated baseline disk scores in UC predicted the subsequent need for advanced therapies (p=0.019), persistent active disease at 12 months (p=0.023) and need for inpatient treatment (p<.001). In CD, elevated disk scores predicted need for advanced therapies (p=0.014), persistent active disease (p=0.015) and showed a weak association with the need for surgical resection within 12 months (p=0.064). These results are summarised in Table 1. After diagnosis and treatment, ongoing disability and psychological symptoms were driven by disease activity. In both UC and CD, the ‘Emotions’ domain fell significantly in those in remission at first follow-up (CD p<.001; UC p=0.008) but was unchanged when the disease remained active (CD p=0.71; UC p=0.72). Conclusion The IBD disk reliably screens for symptoms of depression and anxiety and identifies risk of adverse treatment outcomes at IBD presentation. Its use in the outpatient setting can support holistic disease assessment and identify those who are most likely to benefit from additional psychological support. Moreover, particularly in UC patients, elevated baseline IBD disk scores should prompt the consideration of treatment escalation early in the disease course.

STUDY ON CHARACTERISTICS AND ORIGIN OF NANO-PORE AND FISSURES FOR DEEP BURIED CRETACEOUS TIGHT GAS RESERVOIR USING NANOTECHNOLOGY IN KUQA DEPRESSION- TARIM BASIN, CHINA

Although buried over eight thousand meters, there is still developing high production from tight gas reservoir with low porosity and ultra-low permeability in the sandstones of Bashijiqike Formation of Cretaceous in Kelasu area of Kuqa depression. It is an interesting issue for the origin of the ultra-deep reservoirs. This paper aims to present the characteristics and origin of the nano-pore and nano fissures of that ultra-deep reservoirs using field emission scanning electron microscope, laser scanning confocal microscope and other high resolution measure experiments. There are developed two kinds of nano-pores with pore diameters between 40 nanometers to 1000 nanometers, and many nano fissures with width between 10 and 600 nanometers in this sandstone reservoir. Based on their petrophysical properties and microstructure characteristics, the nano pores are connected by those nano fissures that are also as valid pore throats. So, there is valid permeability in sandstones with even very low porosity. The effective combination between nano pores and pore throats is the key factors for high production in this tight gas sandstones. This point can help us to predict gas reservoirs with effective and recoverable reserve in this kind of ultra-deep gas field, also maybe in other similar gas field.

Changes in the Demographic Depression Index by Settlements of Croatia in the Inter-Census Period 2011–2021

The long-term decrease in the total number of inhabitants, the ageing of the population and the social marginalisation of rural areas have caused negative demographic trends in almost the entire Croatia. The concepts of extinction, demographic depres- sion, and demographic endangerment are most often associat- ed with the phenomenon of demographic decline and economic decline in settlements. This paper compares the demographic depression index (IDD) by settlements in Croatia for the 2011– 2021 period, based on 11 demographic criteria defined by Mrđen and Marić (2018). The average IDD value of all settlements in Croatia for 2011 was 2.22 (depressed/edge of demographic depression), while for 2021 it was 2.20. The largest share of settlements for both 2011 and 2021 belongs to demographically depressed area. The smallest share of settlements belongs to the category of extremely vital area. If the absolute change in the number of settlements by IDD is ob- served, the largest increase was recorded in the demographical- ly depressed area, and the largest decrease was recorded for the edge of demographic depression. The categories of vital and extremely vital areas did not register an increase. IDD can be applied in the analysis, i.e., recognition of the demographic resources of an area with the aim of reducing inequality in socio-economic development, i.e. spatial imbalance.

White Depressed Areas and Tumor Infiltrating Lymphocytes: The Cancer Cure That Lies Within?

This brief overview is inspired by seminal contributions by the late Dr. Martin C. Mihm, Jr. who provided a basis for recognition and better understanding of interactions between lymphocytes (tumor-infiltrating lymphocytes [TILs]) that home to and permeate cancers. In primary melanomas, this phenomenon may produce what Dr. Mihm called white depressed areas, prescient clues to what would fuel future attempts at harnessing anticancer immunity. The critical and sequential TIL attributes of antigenic stimulation, homing, and effector-target cell apoptotic injury herein are briefly reviewed in light of more recent advances in the field of immuno-oncology. The intent is to emphasize how fundamental clinical and histopathological observations, as forged by Dr. Mihm and his associates, have led to critically important prognostic paradigms as well as to translational insights that now have become transformative in the field of cancer immunotherapy.

EU Social Economy: Means to ending Inequality?

In recent years, the European Union has been facing increasing technological, economic, environmental and social challenges. The issues of strengthening the social economy are becoming increasingly important in an era of instability and uncertainty in the prospects of global development. The subjects of this business model can play a positive role in achieving the UN Sustainable Development Goals, increasing productivity and competitiveness of both individual enterprises and states and their associations through increased solidarity at the territorial and local levels, reducing poverty and inequality. The social economy is designed to create quality jobs, guarantee equal learning opportunities and provide the necessary social services, especially for vulnerable segments of the population, such as migrants, persons with disabilities and unskilled workers. To realise its mission, its enterprises and organisations need to collaborate with public authorities, stakeholders and users capable of finding solutions to collective problems, such as ethical financing and socially responsible banking. This collaboration can give impetus to social inclusion, economic development and territorial cohesion in depressed underdeveloped areas and regions. Today, social indicators in EU countries such as poverty, inequality, long-term and youth unemployment continue to be high, making it difficult to ensure social sustainability. This article analyses EU policies on the social economy as well as its ecosystem in the region.

The formation of an energy-efficient quarter of the university campus as part of the reconstruction of the depressed production area of the Krasny Oktyabr metallurgical plant in Volgograd

The formation of an energy-efficient quarter of the university campus as part of the reconstruction of the depressed production area of the Krasny Oktyabr metallurgical plant in Volgograd

Land surface temperature and socioeconomic residential segregation in the Metropolitan Zone of San Luis Potosí, Mexico

Economic growth and urban sprawl in territorial systems produce an uneven distribution of infrastructure and services. This creates residential areas with high capital gains that are affordable only for the middle and upper classes. For lower-income groups, the only options are depressed urban areas with limited infrastructure. The economic dynamics of urban systems require large amounts of energy that contribute to an increase in the land surface temperature (LST). The objective of this research was to analyze urban heat and exposure inequalities of socioeconomically segregated groups during the last thirty years in the Metropolitan Zone of San Luis Potosí–Soledad de Graciano Sánchez, Mexico. A spatial and temporal analysis of Landsat 5 and 8 satellite imagery was used to determine the variation in LST over the last three decades. Socioeconomic residential segregation was calculated using the Theil index. With this data, a self-segregated sector with high capital gains was identified. This sector exhibited significant differences (p < 0.05) of −2.00 °C and −1.58 °C in average LST in the spring months compared to the most depressed urban sectors characterized by the largest concentrations of overcrowded social housing and the lowest educational indexes. The spatio-temporal patterns suggest that urban expansion has led to an unequal distribution of ecosystem services for temperature regulation, leaving the most vulnerable groups with higher exposure to the effects of urban heat.

Fossil corals with skeletal lesions comparable to modern ones

Whereas post-mortem bioerosional features such as bivalve, sponge or worm borings are frequently preserved in ancient corals, reports of ante-mortem skeletal anomalies on Cretaceous specimens are rare. Here, we document the occurrence of fossil skeletal lesions produced during the life span of the colonies in exceptionally well-preserved Aptian (Early Cretaceous) scleractinians from the Maestrat Basin (East Iberia). These ante-mortem damage features are characterized by millimetric to centimetric areas of skeletal depression, as well as upward growth around damaged areas indicating regeneration. Depressed skeletal lesions are commonly overprinted by post-mortem lithophagid borings. Distribution of skeletal anomalies on the colonies can be focal or multifocal, and their location basal, medial and/or apical. The extent of the skeletal anomalies can be mild (occupying &lt;10% of the colony) to extreme (occupying ≥50% of the colony). The edges of the skeletal anomalies are distinct (disk-shaped) or annular (ring-shaped), the margins are mainly smooth to uneven, and the shapes are circular, oblong, pyriform, linear, or irregular. The skeletal anomalies exhibited by the corals are comparable to tissue lesions produced in modern corals either by predation, bioerosion or disease, which may be followed by skeletal overgrowth or denudation. Although demonstrating disease in fossil colonies is challenging, there is no reason to believe that corals did not experience diseases back in the Cretaceous. This paper gives an example of the potential of coral anomalies originating from tissue lesions and skeletal damage to be preserved in the geological record, a factor that may have been often overlooked in the study of fossil coral communities.

Determinants of District/City Income Disparity in Bali Province

In regional scale of Bali Province infected symptom disparity marked income​ with Still concentrated development of the South Bali region compared to other parts of Bali. The goal study This For identify disparity income districts / cities in Bali Province 2018-2023 and analyze influence growth economy, power work, level education, allocation funds, and capital expenditures on disparity income district / city Bali Province is good in a way simultaneous and also partial. Research This use method quantitative and using secondary data obtained​ from the Central Bureau of Statistics. Data analysis techniques using Williamson index and Klassen typology as analysis disparity and continued with multiple linear regression For analyze influence growth economy, power work, level education, allocation funds, and capital expenditures on disparity income. Research results show growth economy, power work, level education, allocation funds, and capital expenditures simultaneous influential and significant to disparity income. Furthermore, growth economy, level education, allocation funds, and capital expenditures partial influential negative and significant to disparity income. Meanwhile, energy Work in a way partial influential positive and significant to disparity income. Research suggestions among other things to do equalization development for poor and depressed areas decrease, increase transportation common connecting​ all areas, development infrastructure and creation field work, availability help education and also scholarship to college tall and also postgraduate, government center still provide allocation funds especially to poor and depressed areas , and maximize potential area so that investors can invest.

Decision-Making Approach for Land Use in Urban Industrial Area Redevelopment Projects

The process of industrial transformation, becoming the most important for building up sustainable cities, is in urgent need for studying alternative options for land use to ensure sustainable city development. Rapid urbanization requires new built-up design in strong correlation with urban spatial planning issues. The objective of this paper is to contribute for the studies of sustainable land use solutions through investigating the problems of the reorganization of depressed industrial areas. The research methodology is based on the multicriteria decision-making method to provide primarily social functions of depressed industrial areas, depending on environmental and economic aspects of their historical location in urban structure. Since the article highlights the concept of the 15-min city to build a polycentric urban spatial structure, the assessment of supply and demand matching of social facilities is based on the analysis of 15 min accessibility to the serviced within either industrial zone and the city on the whole. The GIS spatial analysis method supports the developed criteria set to evaluate main city functions. The research provides the methodology for defining the priority land use solution for a specific industrial area in a specific location. The proposed methodology suggests a procedure for evaluating the importance of the land use composition for the city community, considering environmental requirements and cost-effectiveness of the project. Three different industrial zones located in the same city are a case study to asses the reliability of the proposed methodology. The research conclusion provides implementing sustainable land-use solutions for improving urban environment quality as well as the quality of life for the population.

RECOGNITION OF DURICRUST GEOMORPHIC SURFACES USING A RELIEF DISSECTION MATRIX

Landforms can orientate the hydrodynamics and distribution of materials on the ground, producing flattened and/or lowered geomorphic surfaces given the evolutionary characteristics from climatic, morphogenetic and pedogenetic factors. This work aims to demonstrate the compartmentalization and association of geomorphic surfaces covered by ferruginous duricrusts in Savannah areas in Brazil according to a relief dissection matrix. This matrix indicates the vertical cutting of the valleys and the interfluvial horizontal dimension of the hills through landform measurements in radar images, classification in alphanumeric codes and statistical correlations. The results indicated details in the compartmentalization of the surface according to the landform roughness, making it possible to link, through data from the dissection matrix and the statistical correlation, the association between the compartments according to summit positions and remaining depressed areas. Despite the fact that more robust measurements obtained from high-precision mappings can point out further landform evolutionary stages, it is understood that a dissection matrix and its statistical correlations can not only compartmentalize the landscape and provide an initial overview of the landscape’s evolution, but also indicate geomorphic surfaces that could have been worked at the same time. In this sense, the recognition of geomorphic surfaces, occurrence of duricrusts and landforms in this work allowed a certain morphogenetic correspondence that can contribute to geomorphological studies, although the results must be observed with caution when verified from the tropical perspective of relief evolution. Keywords: Valley Cutting; Interfluvial Dimension; Dissection Matrix; Geomorphic Surfaces; Duricrusts

On the Possible Climatic Consequences of the Large Oil Spills in Oceans

In the North Atlantic and the Northern Ocean, from the second half of 2010 to 2014, satellite imagery data showed increased surface water temperatures (in the Icelandic Depression area in September–October 2010, it was 1.3 °C higher than in 2009). The peak of the annual sum of mean monthly ocean surface temperatures near the Icelandic Depression in 2010 (109.3 °C), as well as the negative values of the monthly averaged North Atlantic Oscillation (NAO) indices, estimated in the second half of 2010 and until March 2011, can be explained by the appearance of an additional film of oil origin on the water surface, formed after an oil spill accident at the Deepwater Horizon drilling rig in the Gulf of Mexico. Insufficient evaporative cooling of surface waters near the Icelandic Depression related to the formation of an additive film due to the influence of pollution of the North Sea by oil can explain the earlier peak in the annual sum of mean monthly ocean surface temperatures near the Icelandic Depression in 2003 (107.2 °C). Although global warming is usually ascribed to increased greenhouse gases in the atmosphere, ocean surface water pollution could increase the heat content of the ocean and explain the steady temperature stratification and desalination of these waters due to the melting of Greenland’s glaciers. Thus, when analyzing the concept of global warming, it is necessary to take into account the aspects of pollution of the ocean surface waters to assess the changes in their capacity to accumulate solar radiation, as well as the changes in the heat content of the ocean mixing zone (~200 m).

Basement Depth Map Estimation and Linear Features Detection Depending on Interpretation of Magnetic Data at Qarun Oil Field and Surrounding Areas, North Western Desert, Egypt

This investigation primarily targets a specific area situated in the northeastern Western Desert and northwest Beni-Suef, covering Wadi Al Rayan area, Gindi basin, Kattaniya inversion, and El-Fayum depression. It extends to the east of the river Nile. This study aims to Evaluate the depth of the basement complex in the area under investigation. The total aeromagnetic intensity data was reduced to the north pole (RTP) for clarity. 2D modeling of this RTP data was then used to evaluate the basement depth. The analysis of basement depth maps revealed significant variations in the subsurface structure of the study area, showing both elevated features (horsts) and depressed areas (grabens). The elevated basement (horsts) was found to be at a depth of approximately 813 meters, while the deepest depression (grabens) reached down to 7600 meters. Based on magnetic data combined with eight wells drilled into the basement complex, a basement lineament map of the area is delineated as a result of the investigation. This map shows a series of large alternating highs and valleys in ENE-WSW, NE-SW and E-W trending bands. Together with other minor trends, these major trends have shaped the basement surface into several tilted fault blocks, creating anticlinal and syncline zones of different depths and directions to form the Qattrani-El Gindi low trends. Whereas the high trend is located in El Fayum, El-Sagha, and Abu Rawash areas. The study helped to re-evaluate the subsurface structures affecting the Qarun oil field's hydrocarbon accumulation.

Correlation Between Health-Related Life Quality and Dyspnea Severity in Aged COVID-19 Survivors in Indonesia

Introduction: COVID-19 is a disease that can severely reduce life quality, particularly in the aged population. The research aim was to establish the correlation between health-related life quality and dyspnea severity within aged COVID-19 survivors.Method: The cross-sectional study was conducted on older COVID-19 survivors at Persahabatan Hospital, Jakarta. The use of WhatsApp® video call and Zoom® video conference applications for audio and video evaluation in data collection. The European Quality of Life-5Dimensions-5L (EQ-5D-5L) and the European Quality of Life-Visual Analog Scale (EQ-VAS) were used to assess health-related quality of life. Modified Borg and modified Medical Research Council (mMRC) dyspnea scale were used to assess dyspnea severity. The data were analyzed using correlation test. Results: Based on 44 data collected, it was found that seven (15.9%) of the participants experienced mild breathlessness, while three patients (6.8%) had severe level of dyspnea on the modified Borg dyspnea scale assessment. The mMRC dyspnea scale assessment indicated that over nine patients (20.4%) had mMRC value greater than one. The study found a significant correlation (p less than 0.01) between the EQ-5D-5L and the modified Borg Dyspnea Scale, particularly in the areas of anxiety or depression (r=0.52), self-care (r=0.51), mobility (r=0.42), and EQ-VAS (r=-0.53). The EQ-5D-5L and the mMRC dyspnea scale showed a significant correlation (p less than 0.01), particularly in relation to usual activities (r=0.69), self-care (r=0.62), and mobility (r=0.65), as well as EQ VAS (r=-0.58).Conclusion: Moderate positive correlations existed between life quality issues including self-care, anxiety, depression and dyspnea severity .

Timing of Laser Intervention on Facial Scars: A 3D Imaging and Scar Scale Analysis in a Retrospective Study.

Scars resulting from injuries or surgical procedures often present both physical and aesthetic challenges. Recent studies have indicated promising results in improving postoperative scar outcomes through the combined use of specific laser technologies. Nevertheless, there remains a crucial need for further exploration to ascertain the optimal timing for initiating such treatments. In this retrospective investigation, a cohort of 47 adult patients who did not require hospitalization was analyzed. These patients were divided into two distinct groups: Group A, which received intervention beginning 2 weeks after their respective operations, and Group B, which commenced intervention 4 weeks postoperation. Each group underwent a comprehensive treatment protocol consisting of five laser sessions. Initially, patients underwent three sessions of V-beam pulsed-dye laser (PDL) therapy followed by two sessions of ablative fractional CO2 laser (AFL) therapy. Evaluation of outcomes was conducted using advanced imaging techniques such as Antera 3D imaging, in conjunction with established scar assessment tools including the Vancouver Scar Scale (VSS) and the University of North Carolina "4P" Scar Scale (UNC4P). All patients successfully completed the full course of five treatment sessions, with no dropouts and no reported adverse events. Baseline cosmetic assessments of scars were equivalent across both groups. In Group A, the mean VSS scores decreased from 7.04 before treatment to 5.29 at 3 months posttreatment and further to 4.33 at 6 months posttreatment. Meanwhile, in Group B, scores decreased from 7.52 to 6.83 at 3 months and 6.17 at 6 months. There were no statistically significant differences in baseline VSS scores between the two groups (p = 0.34). At both the 3- and 6-month follow-up points, mean VSS scores were significantly lower in Group A compared to Group B (p < 0.05). Similar trends were observed in UNC4P scores. Statistically significant differences were noted across all time points (baseline, 3 months, and 6 months posttreatment) for both VSS and UNC4P scores (p < 0.05). Subset analysis revealed greater improvements in texture and depression volume at 3 months posttreatment, while improvements in depression area, depth, elevation variation, and area were more pronounced at the 6-month mark. Early intervention using the combined 595-nm pulse dye laser and CO2 ablative fractional laser (AFL) 2- and 4-weeks post-surgery proves to be an effective and safe method for improving scar outcomes, particularly for facial surgical scars when treatment starts 2 weeks after surgery. However, further research is needed to refine our understanding and address potential study limitations.

Can temperature be a low-cost tracer for modelling water age distributions in a karst catchment?

To investigate the feasibility of using temperature for tracking rainfall-runoff processes in karst catchments, this study developed a tracer-aided conceptual model using temperature as a tracer by coupling water and heat transport processes at the catchment scale. The model was calibrated and validated using hourly hydrometeorological and temperature data from a 1.25 km2 karst catchment in south-western China. The results showed that the model was able to capture the water flux and temperature dynamics of different landscape units in the karst catchment. Utilizing this framework, the model delineated the flux age distribution within different landscape units, as well as the overall water transit times through the catchment. The average flux ages were determined to be approximately 80 days for the hillslope unit, 452 days for the slow flow system, and 260 days for the fast flow regime within the depression areas. These estimations align broadly with those acquired using stable isotopes as tracers. Comparative analysis revealed that the flux age distributions derived from both temperature and isotopic tracers exhibited analogous patterns at the catchment outlet and across the hillslope compartments. However, the simulations based on temperature hinted at a heightened proportion of exceedingly young and decidedly old water in the outflow, alluding to a potential overestimation of these extreme age classes by the temperature-tracer model. From the temperature-simulated transit time distribution, about 31 % of the precipitation entering during the study period have left the catchment within 3 years, and a notable proportion of rain water was either stored in the aquifer or lost through evapotranspiration. The general characteristics of the transit time distribution simulated using temperature was similar with that simulated using isotopes, though a higher proportion of precipitation being drained by fast flows was inferred from the transit time distribution simulated using temperature. Collectively, our study demonstrated that temperature can serve as a cost-effective tracer for modelling of water age distributions and associated hydrological processes in karst catchments.

New understanding on the interplay of longitudinal and transverse sediment dispersal: Combination of 3D seismic profile and u-pb ages of detrital zircons of Paleogene sedimentary rocks in the northern South China Sea

The northern South China Sea (SCS) experienced a significant transition from a lacustrine to marine environment in the Paleogene, and its deep-water basin of Zhu-II Depression is in particular extensively studied due to its richness in oil and gas resources. However, limited number of boreholes in the deep-water area has long constrained a better understanding on the provenance of the Paleogene strata and the associated sediment transport processes. In this study, detrital zircon U-Pb ages and three-dimensional (3D) seismic-reflection data were systematically employed to investigate the “source-to-sink” pathways and interplay of longitudinal and transverse sediment dispersal. Our results indicate that the Zhu-II Depression sediments of the northern SCS were predominantly derived from the surrounding nearby paleo-uplifts in the early and middle Eocene. A significant provenance shift took place in the late Eocene, when the local paleo-uplift source was replaced by a distant source from the western SCS. Sediments were transported from west to east by the “Kontum-Ying-Qiong River” as a longitudinal dispersal. In the Oligocene, the “Kontum-Ying-Qiong River” delivered large amounts of sediments from Central Vietnam to the eastern part of the northern SCS. Meanwhile, the Pearl River gradually evolved through regional tectonic processes and influenced the deep-water area of Zhu-II Depression as a transverse dispersal. Sediments from both “Kontum-Ying-Qiong” and Pearl Rivers converged and deposited as deep-water deltas in the Zhu-II Depression. This dual provenance system in the northern SCS deep-water area was featured by the interplay between longitudinal and transverse sediment dispersal. It was largely controlled by the tectonic-palaeogeographic pattern inherited from the Mesozoic arc system.

Study on the Influencing Factors of Oil Bearing and Mobility of Shale Reservoirs in the Fourth Member of the Shahejie Formation in the Liaohe Western Depression

Oil content and the movability of shale oil are important indicators for the evaluation of continental shale oil. In recent years, the sandwiched shale oil in the fourth member of the Shahejie Formation in the Liaohe Western Depression area of the Bohai Bay Basin has shown great exploration potential, while the understanding of shale oil content and the movability of shale oil is weak. In this study, through a combination of core observations and experiments, we clarified the shale lithofacies types in the fourth member of the Shahejie Formation in the Liaohe Western Depression and explored the influencing factors of the characteristics in the oil-bearing and movability of shales in different lithofacies. The results of the study show that the organic matter content of the shale is high (TOC = 2.2–4.3%), but the maturity of thermal evolution is low (Ro = 0.38–0.55%), and the mineral component is dominated by clay minerals (30.3–72.7%), with quartz, feldspar, and other feldspar minerals developing secondarily. According to the content of organic matter, the mineral component, and the sedimentary structure, five types of lithofacies can be classified: organic-rich laminated clay-bearing felsic shale lithofacies (LS1), organic-rich laminated clay felsic mixed shale lithofacies (LS2), organic-rich layered clay felsic mixed shale lithofacies (LS3), organic-containing massive felsic-bearing clay shale lithofacies (LS4), and organic-containing massive clay felsic mixed shale lithofacies (LS5). The oil content of shale is mainly affected by the organic matter. The rate of increase in oil content of shale is fastest when the organic matter content is between 2 and 4%. The movability of shale oil is mainly controlled by the sedimentary structure, mineral component, and microscopic pore structure; the more the shale laminae is developed, the lower the clay content is, and the more the pore space is developed, the better the movability of shale oil is. Combined with the results of the shale oil content and mobility analysis in the study area, LS2 and LS3 are the dominant lithofacies in the fourth member of the Shahejie Formation in the study area, followed by LS1 &gt;LS5 &gt;LS4, so shale oil exploration should focus on the development of LS2 and LS3.