Basin Evolution Research Articles

Middle Paleocene to early Eocene sedimentological evolution of the central-eastern Sirt Basin (Libya): biostratigraphy and depositional environment

AbstractThe depositional history of the central-eastern Sirt Basin of Libya during the Middle Paleocene to Early Eocene is characterised by the deposition of shallow-marine carbonates and hemipelagic claystone and marlstone. To gain a better understanding of the depositional history during this period, we dated the hemipelagic marlstones using planktonic foraminifera and calcareous nannoplankton to refine the stratigraphic relationships with the intercalated shallow-marine limestones. During the Danian, a broad carbonate shelf formed in the eastern sector of the basin. Transgression in the Early Selandian resulted in the deposition of claystones and limestones. The shallow-marine carbonate factory recovered rapidly during the Early-Middle Selandian, forming the Upper Sabil carbonate ramp, however, it became subaerially exposed and eroded in the shallowest areas. The resulting domal structures represent carbonate ramp erosional relics as demonstrated by biostratigraphic results combined with microfacies studies. Whereas in the deeper-water areas of the Upper Sabil carbonate ramp, the deposition was probably continuous throughout the Paleocene–Eocene, the shallow-marine limestones were exposed for about 6 Ma until they were drowned in the Early Eocene. A distinct argillaceous unit, with intercalated shallow-marine limestone beds, was deposited in the basinal areas between the domal structures during the Late Selandian–Thanetian stages. In this study, we define this deposits as the Intisar Formation. The overlying Late Paleocene/Eocene Harash Formation consists of shallow-marine limestones. This trangressive unit infilled the Upper Sabil paleotopography with a 2.5 Ma stratigraphic gap. The hemipelagic marlstone of the Kheir Formation was deposited above the Harash Formation and partly above the Upper Sabil paleotopography during the Ypresian, driven by the major sea-level rise following the Eocene Thermal Maximum-2 (ETM-2). Therefore, a substantial stratigraphic gap of at least 6 Ma is documented on the crest of the domal structures, which were subsequently overlain by the Kheir Formation. Graphical abstract

Comparison of neotectonic intermontane basins of Northern Armenia and Eastern Türkiye

The results of comparative analysis of the structure and history of the Neogene-Quaternary development of 18 inrermontane basins in Northern Armenia and Eastern Türkiye are presented. The research is based on expeditionary work carried out by the authors in 2012–2023, and supplemented by published materials from other researchers. Palaeontological, magnetostratigraphic and radioisotope data on the stratigraphy of the basins are analyzed. The comparison made it possible to identify four stages of basin development, expressed by the nature of sedimentation: (i) marine sedimentation; (ii) predominantly lacustrine accumulation of fine-grained clastic material transported from low uplifts; (iii) lacustrine-alluvial sedimentation with a significant proportion of coarse material carried down from neighboring uplifts: (iv) involvement of the basins in the total rise of the region, which in most depressions is expressed by increased incision of watercourses into previously emerged landforms, and in the Sevan depression is combined with ongoing lacustrine-alluvial sedimentation. A consistent rejuvenation of stages (i)–(iii) of the basin development in the northern direction is revealed. It is caused with the growth and expansion to the north of the uplift of the Taurus Ridge in the process of its thrusting onto the Arabian Plate. At the same time, the development of the basins revealed the impact of tectonic events in the Middle and South Caspian. It was expressed in the Early Pliocene by the unconformity and the appearance of coarse clastic rocks, reflecting the increasing contrast of vertical movements between the Caucasian and Caspian regions, and at the end of the Late Pliocene by the penetration of waters of the Akchagylian transgression of the Caspian Sea into some basins. These features of the development of the basins did not depend on differences in their origin, which was determined by the influence of several factors. Among them, the main ones were movements on faults as a result of the interaction of lithospheric blocks and subsidence, caused by movements of sublithospheric masses, expressed by volcanism. Secondary roles were played by the behavior of the ophiolitic substrate and the tectono-volcanic damming of river valleys.

Effect of Vegetation Growth, Agricultural Irrigation and Climatic Variability on Streamflow in Wujiang, China

Vegetation restoration and farmland irrigation are important environmental factors affecting the water cycle process in basins. Analyzing the impact of vegetation restoration and farmland irrigation on runoff is an international frontier and hot topic in current research, which is crucial for the management and protection of water resources, especially for the ecological protection and high-quality development of basins. Based on the normalized difference vegetation index (NDVI), effective irrigated area (EIA), and meteorology and hydrology data for Wujiang River (WJR), this research aims to quantitatively calculate the influence degree of vegetation recovery, agricultural irrigation, and climatic variability on discharge alteration in WJR. First, Mann–Kendall and Pettitt approaches were used for recognizing the mutation year of streamflow data at Wulong station from 1982 to 2015. Then, a corrective Budyko model was built by constructing multiple linear regression equations for the NDVI, climate factors, EIA, and Budyko parameters. Finally, the corrective Budyko model was adopted to reveal how vegetation restoration, agri-cultural irrigation, and climate variation influence discharge alteration in WJR. The results showed the following: (1) Both runoff depth (R) and rainfall (Pr) exhibited a non-significant de-clining tendency, while potential evapotranspiration (ET0) demonstrated a non-significant in-creasing tendency. The NDVI and EIA both demonstrated a notable upward tendency (p<0.01). (2) The mutation year of discharge in WJR was 2004. (3) The underlying surface parameters ω have a strong correlation with vegetation, agricultural irrigation, and climate factors. (4) The contribution of rainfall (Pr), potential evapotranspiration (ET0), NDVI, EIA, and human activities to runoff depth in WJR were 57.34%, 24.67%, -11.75%, 11.71%, and 18.02%, respectively. This re-search is helpful for elucidating the effects of ecological construction measures and agricultural irrigation on streamflow in WJR, and offers great scientific significance and practical value for understanding the evolution mechanism of water circulation and for managing regional water resources.

Tectonic Evolution and Sedimentary Responses of Palaeocene–Eocene Tethys Himalayan Foreland Basin in Southern Tibet

ABSTRACTThe tectonic evolution of the Palaeocene–Eocene Tethys Himalayan foreland basin plays a crucial role in reshaping the collisional orogenic process of the Yarlung–Tsangpo oceanic basin. However, studies examining the sedimentary response during the tectonic evolution of the foreland basin are lacking. In this study, through a detailed field investigation and analysis of Palaeocene–Eocene strata in the Tingri area, we clarified the evolution of the Tethys Himalayan tectonic regions and its sedimentary response. Carbon and oxygen isotopes, geochemistry and detrital zircon U–Pb dating demonstrated that the lower Palaeocene Jidula Formation and upper Palaeocene–lower Eocene Zongpu Formation were deposited in a coastal–shallow marine environment, with the detritus sourced from the northern Indian passive margin. The upper Eocene Pengqu Formation was deposited in a deltaic environment, with its detritus sourced from the Gangdese arc and the Yarlung–Tsangpo suture zone at the active continental margin. Combined with the nearshore subaqueous fan branch channel of the Jidula Formation and the slump deformation of the Zongpu Formation, the Palaeocene–Early Eocene southern Tethys Himalaya in the Tingri area was located in the forebulge of the peripheral foreland basin. The marine–continental interactive delta of the Pengqu Formation and its provenance from the Gangdese magmatic arc indicate that the Tingri area was situated in the foredeep of the peripheral foreland basin during the Late Eocene. The study provides valuable insights into the collisional orogenic processes between the Indian and Eurasian plates.

Geometry of large normal fault growth and linkage with temporal constraints: a case study on the Lanliao fault in Dongpu Sag, Bohai Bay basin, NE China

The Dongpu Sag exhibits highly representative structural features of the Bohai Bay Basin. By utilizing time depth quantification (TDQ) technology, geological profiles were generated through the processing of seismic data with a velocity model. These profiles were integrated to investigate the linkage geometry and timing of the Lanliao fault, the eastern boundary fault of the Dongpu Sag. Structural analysis revealed at least five original fault segments of the Lanliao fault, each initiating independently during the early growth phase. The development of these isolated fault segments began in the early Eocene, which is concurrent with the deposition of the Es4 member. The southern fault segments were active earlier but became inactive later as the northern segments gained activity during the Es3 member. Transverse anticlines separate the northern and southern faults. By the time of the Es2 member, all segments had linked, forming a continuous boundary fault across the transverse anticlines. As the Dongpu Sag expanded, the depocenter relocated. The southern fault formed a graben, known as the Gegangji subsag, controlling the depocenter during the Es33 and Es32 members. The depocenter of the Es31 member shifted northward swiftly, developing into a half-graben depocenter called the Huzhuangji subsag. In the post-linkage development phase, the activity of the Lanliao fault decreased over time, with displacement becoming more concentrated on the Huanghe fault, an intrabasin fault. The Huanghe fault then dominated basin sedimentation, moving the depocenter to the Mengmangji subsag. This study demonstrates that the fault linkage is a significant event in basin evolution, exerting considerable control over sedimentation and the overall evolution of the basin.

Right to Food Policies, Justice and Sovereignty in Nigeria

This study assessed the right to food policies, justice and sovereignty in Nigeria. The main areas of concentration were: introduction, meaning of food policy, some food policies in Nigeria, types of policies, audit of right to food policies in Nigeria, past policy articulations (1900 – 1999), food policy articulation and policy thrust in 2003, food policy legislations, sovereignty of food and agricultural development among many others. The study indicated that food policy is a public declaration that conveys the decisions to pursue a specific course of action aimed at improving food production practices, ensuring output growth and the overall development of the food sector. Some food policies in Nigeria are; food crop production policy, livestock production policy, food commodity storage policy among others. The study identified three types of polices namely; position declaration, policy statements and discussion papers. Past policy articulations are: Timber/non timber policy 1937, food policy 1946 and food policy for the western region 1952. Some policy legislations were identified, namely: adulteration of produce ordinance No.67 of 1917; 29 of 1920, 8th November 1917, Weight and measurements Act No. 32 of 1974 to June 1975 and River Basin Development Authorities Act No.35 of 1st October, 1986. Some inventory of right to food sovereignty strategies in Nigeria includes: Sovereignty strategy formulations, commodity boards, National Accelerated Food Production Project (NAFPP), National Livestock Development Project (NLDP), Operation Feed the Nation (OFN) and Green Revolution among very many others. One major problem of food policy implementation is lack of a well-defined programme. In conclusion, Right to Food Policy, Justice and Sovereignty Implementation means money spent, laws enforced, employees hired, plan of action formulated and carried out successfully for the development of the Nigerian food sub-sector. But the problem with Nigerian food policies is the structure among which is the absence of central coordinating members. Also, the study recommended that there is the need for government to set institutions that will monitor the planning and execution of food polices projects. Key words: Agricultural Development, Food, Justice, Legislations, Nigeria, Policies, Rights, Sovereignty

Study on the Sand Reduction Effect of Slope Vegetation Combination in Loess Areas

Slope erosion in the Loess Plateau region has long been a concern, and vegetation plays an important role in slowing down erosion and controlling sedimentation. However, a single vegetation model shows some limitations when facing complex natural conditions and variable rainfall events. Therefore, this study investigated the influence mechanism of vegetation configuration on slope sand production at different slopes through theoretical analyses and indoor experiments. The results of the study showed that certain factors, such as vegetation configuration mode, flow rate, runoff power, runoff velocity, and runoff shear, are closely related to slope runoff sand production. The specific findings are as follows: (1) Under the condition of slope gradient of 2°, the sand reduction effect of the rigid–flexible single-row staggered configuration is the most significant, and the sediment production is reduced by 29.89%. (2) With the increase in the slope gradient and flow rate, the sand production on the slope surface rises significantly, and when the slope gradient is increased from 2° to 6°, the average sand production is increased from 1.43 kg to 2.51 kg.(3) The erosion reduction effects of different vegetation configurations were in the order of rigid–flexible single-row staggered combination > flexible vegetation single combination > rigid–flexible double-row staggered combination > rigid vegetation single combination > upstream rigid downstream flexible combination > bare slope. This study provides a theoretical basis for optimizing the vegetation configuration for effective sand reduction and provides an important reference for the sustainable development of the Yellow River Basin.

Geological and geochemical aspects of modeling of hydrocarbon systems

Forecasting the phase-genetic types of hydrocarbons is the most important stage in modelling geological hydrocarbon systems. This is because accurate qualitative and quantitative assessment of potential reserves is necessary for making informed investment decisions in exploration activities. Improving the precision of qualitative and quantitative oil and gas forecast can help reduce geological risks in asset development and increase investment efficiency. Therefore, technologies that allow modelling of hydrocarbon systems are becoming ever more important. This study aims to explore the key geological and geochemical aspects of hydrocarbon system modelling. Hydrocarbon systems refer to interconnected elements and geological processes influencing hydrocarbon formation in sedimentary basins. The study emphasizes that the "oil window" concept, or the theory of hydrocarbon formation phases, provides the theoretical basis for hydrocarbon systems. This concept consistently encompasses the entire history of sedimentary basin development, the evolution of thermal and thermobaric regimes in sedimentary deposits, the transformation of organic matter, hydrocarbon generation, migration, accumulation, and preservation processes. Using the results of modelling of hydrocarbon systems to evaluate geological risks and the economic impact of exploration activities can be a powerful instrument for companies that make investment decisions in geological exploration.

Provenance and tectonic evolution of the forearc basin along the northwestern Central Qilian belt, northeastern Tibet

The age and properties of detrital zircon grains in a forearc basin provide crucial information on the history of convergent plate margins. These data can be used to constrain provenance dispersal patterns, establish source-to-sink relationships, and reveal the tectonic framework and subduction history. The Qilian orogen in the northeastern margin of the Tibetan Plateau records the tectonic history of the Proto-Tethys Ocean from its initial spreading and subduction to final closure. However, the timing of subduction initiation and the subduction polarity of the Proto-Tethys Ocean remain controversial. The Qilian orogen includes the North Qilian, Central Qilian, and South Qilian belts. A succession of sedimentary rocks along the northwestern margin of the Central Qilian belt, previously considered to be Precambrian in age, has been redefined based on detailed field investigation and geochronology. U-Pb analysis of detrital zircon grains from metasedimentary rocks of the Gongcha Group of the northwestern Central Qilian belt yielded Paleozoic ages between 530 and 470 Ma, with prominent Mesoproterozoic and Paleoproterozoic ages between 1800 and 1000 Ma. In contrast, the overlying Duoruonuoer Group yielded predominantly early Paleozoic ages between 465 and 434 Ma, with a few older age populations. This change in source is reflected in a substantial increase in volcanic detritus within the Duoruonuoer Group as compared to the Gongcha Group. The detrital zircon age spectra and lithologic characteristics indicate the Gongcha and Duoruonuoer Groups constitute the lower and upper volcanic-sedimentary strata in the forearc basin. Based on resemblances of statistical ages and εHf(t) values of zircon, we interpret that the early Paleozoic intrusive and volcanic units and Precambrian basement rocks of the Central Qilian belt were the main source of the Gongcha and Duoruonuoer Groups, verifying the southward subduction of the North Qilian Ocean, a portion of the larger Proto-Tethys Ocean, beneath the Central Qilian belt. The detrital zircon ages reveal that the initial subduction of the Proto-Tethys Ocean in the Qilian orogen occurred ca. 530 Ma and closed ca. 435 Ma. These forearc sedimentary units constitute the tectonic boundaries between the Central Qilian belt and North Qilian belt.

Palaeogeographical and eodiagenetic settings of host‐replacing phreatic calcrete intervals developed in mud deposits of the Famennian Kinnesswood Formation in the Pennyseorach Subbasin of south‐west Scotland

ABSTRACTIn the Pennyseorach Subbasin of south‐west Scotland, the Famennian Kinnesswood Formation of the Inverclyde Group includes several, ca 1 to 3 m thick erosional remnants of host‐replacing phreatic calcrete hardpans developed in mud deposits. The latter are most unusual hosts for such calcretes due to their relative impermeability, which would normally prevent them from sufficiently accommodating the circulation of an aquifer. In previously documented phreatic calcretes, mud deposits clearly acted as aquicludes that sharply constrained calcrete development. In the Kinnesswood Formation at Pennyseorach, tall desiccation fissures allowed groundwater to circulate in thick, semi‐consolidated mud deposits. Because of the inferred development of an adjacent evaporitic basin, the mixing of fresh and evaporitic groundwaters raised the pH enough for the replacement of phyllosilicates by calcite to occur along the fissure walls, forming ‘fissure calcretes’. The latter gradually expanded and eventually coalesced into mature, ‘columnar host‐replacing phreatic calcrete hardpans’ in which 90 to 100% of the muddy host material was replaced by calcrete. At Pennyseorach, host‐replacing phreatic calcrete hardpan formation not only affected the transition zone between the Doughend Sandstone and Foul Port Members of the Kinnesswood Formation (the Dunagoil Calcrete interval), as in other localities of south‐west Scotland, but also affected the uppermost part of the formation, which is marked by several erosion surfaces downcutting into columnar host‐replacing phreatic calcrete hardpan intervals in association with the episodic rise and fall of base‐level. These newly recorded host‐replacing phreatic calcrete hardpan intervals from the upper part of the Kinnesswood Formation have a tightly constrained stable isotopic signature that is distinct from that of both the Dunagoil Calcrete and the successive host‐replacing phreatic calcrete hardpans of the Visean Clyde Sandstone Formation within the same group, underlining their potential as stratigraphic markers and palaeoenvironmental indicators.

Tectonostratigraphic models of an extensional back-arc basin: inferences for the evolution of the Pannonian Basin system

The subsidence history and sedimentary architecture of extensional basins are controlled by the interplay between tectonics, mantle dynamics, and climatic variations. Observations from outcrop to regional seismic scales coupled with numerical modelling techniques, including basin-scale stratigraphic, crustal-scale tectonic and mantle-scale subduction models contribute to quantify basin evolution. Here, we review and discuss both tectonic and stratigraphic applications of such models and compare them with observations from the Pannonian Basin system of Central Europe. We show that diachronous localization of back-arc extension, crustal thinning, asthenospheric upwelling and subsequent thermal relaxation are superimposed on an overall slow plate convergence. These processes result in contrasting subsidence and uplift patterns and a variable heat flow evolution in different parts of the basin system. The crustal stress-field of the subbasins does not always reflect their contrasting vertical motions. Extensional deformation generally migrates from the basin margins towards the basin centre. Structural inversion is localized along hot and weak inherited zones from the Middle Miocene to Present. Tectonic subsidence focuses sedimentation along deep depocenters, sourced by exhumed footwalls and from the neighbouring orogens. The overall post-rift sediment progradation are influenced by inherited bathymetries from the preceding syn-rift stage and by enhanced differential vertical motions.

Rainfall Erosivity over Brazil: A Large National Database

Rainfall erosivity (RE) represents the potential of rainfall to cause soil erosion, and understanding its impact is essential for the adoption of soil and water conservation practices. Although several studies have estimated RE for Brazil, currently, no single reliable and easily accessible database exists for the country. To fill this gap, this work aimed to review the research and generate a rainfall erosivity database for Brazil. Data were gathered from studies that determined rainfall erosivity from observed rainfall records and synthetic rainfall series. Monthly and annual rainfall erosivity values were organized on a spreadsheet and in the shapefile format. In total, 54 studies from 1990 to 2023 were analyzed, resulting in the compilation of 5516 erosivity values for Brazil, of which 6.3% were pluviographic, and 93.7% were synthetic. The regions with the highest availability of information were the Northeast (35.6%), Southeast (30.1%), South (19.9%), Central-West (7.7%), and North (6.7%). The database, which can be accessed on the Mendeley Data platform, can aid professionals and researchers in adopting public policies and carrying out studies aimed at environmental conservation and management basin development.

A novel framework reveals anthropogenic stressors of phosphorus polluted river-lake connection water system in Poyang lake basin of China

Poyang lake (PYL), as China's largest freshwater lake, has been suffering from increasing total phosphorus (TP) pollution associated with rapid basinal socio-economic development. However, anthropogenic phosphorus stressors were rarely examined in PYL basin due to its large-scale and complex river-lake connection water system, hampering phosphorus pollution control efforts. In this study, water pollution stress from multiple anthropogenic activities is quantitatively examined in PYL basin based on a newly developed framework coupling grey water footprint (GWF) analysis with the SPARROW model. Results show that the phosphorus source-sink process in PYL basin has been well simulated by SPARROW model quantifying an overall TP delivery rate of 0.39, with catchments closer to PYL showing higher delivery rate of phosphorus (up to over 0.8). The GWF analysis demonstrates that anthropogenic phosphorus sources have imposed much higher pollution stress on PYL than its inflowing rivers, with twelve catchments nearby PYL identified as critical source areas of TP contamination. Agricultural farming, livestock & poultry production, and urban household are recognized as the dominant anthropogenic stressors burdening water environment of PYL. Based on these, policy recommendations are provided for advancing control of the phosphorus pollution stressors. The methodology is effective in refined examination of water pollution sources, which is expected to be applied in other watersheds providing informative diagnosis of water issues especially in lakes.

Study of the Dynamic Adaptive Calculation Method for River Water Environmental Capacity

Controlling the total amount of river pollutant discharge is an important means of water resource protection and management, and it is also a necessary condition for ensuring the normal functioning of water areas. The total amount of pollutant discharge is closely related to the water environmental capacity (WEC). Shifting from the traditional method of calculating WEC to dynamic analyses and calculations, concerning practical applications, in this paper, a dynamic adaptive calculation method is proposed for the river WEC that considers the changes in adaptive demand and hydrological conditions. In this method, the dynamic WEC is represented by intervals based on dynamic changes in different spatial and temporal scales, various calculation methods, hydrological conditions, and parameters. According to the calculation results for the WEC, a variable interval was formed. Taking the Shaanxi section of the main stream of the Wei River as the research object, with the support of an integrated platform, the dynamic adaptive calculation of the WEC in the Shaanxi section of the Wei River was realized, and a corresponding simulation system was constructed. The verification results show that (1) the dynamic calculation of WEC can be realized by freely combining different model methods and calculation conditions; (2) the WEC is described using a variable interval, which has strong applicability and operability; and (3) the simulation system can quickly adapt to the changing needs of practical applications and provide managers with visual and credible decision support. The research results provide a theoretical basis for river water environment pollution prevention and environmental management decision-making and help in the high-quality development of the river basin.

Spatiotemporal Evolution Characteristics and Influencing Factors of Industrial Carbon Emissions in the Yellow River Basin

Scientific assessment of industrial carbon emissions in the Yellow River Basin and identification of its influencing factors are of great importance for promoting green transformation, ecological protection, and high-quality development of the Yellow River Basin. Considering nine provinces in the Yellow River Basin as the research objects； using relevant data on industrial development and energy consumption in the Yellow River Basin from 2000 to 2019； and with the help of IPCC carbon emission measurement, spatial autocorrelation, and LMDI decomposition, the spatial and temporal evolution characteristics and influencing factors of carbon emissions from industries and industrial sectors in the Yellow River Basin were analyzed. Reasonable suggestions were put forward for reducing the carbon emissions from industries in the Yellow River Basin. The results showed that： ① From 2000 to 2019, industrial carbon emissions in the Yellow River Basin showed a fluctuating growth trend, with a decreasing growth rate. The spatial pattern changed from "low in the upstream and high in the middle and downstream" to "high and low value distribution," and the spatial difference gradually expanded. ② The high carbon industry was the most important source of industrial carbon emissions in the Yellow River Basin, accounting for 96.35% of the carbon emissions between the industries with a continuous growth trend, which was a significant difference. The middle and low carbon industry carbon emissions and the total proportion was low, showing different fluctuations； nine provinces and nine industrial industries had significant spatial variability. ③ Energy structure intensity, economic scale, and population scale promoted the increase in industrial carbon emissions in the Yellow River Basin and energy consumption intensity had an inhibitory effect on the increase in carbon emissions. The economic scale effect was positive and significant, which offset the negative effect of energy consumption intensity. Spatial variability was observed in the contribution value of the influence effect of the factors affecting the carbon emissions of the industry in nine provinces.

Geomorphic index-based landscape evolution study for the extraction and interpretation of knickpoint and channel steepness in the mandakini catchment, western himalaya.

Geomorphometric analysis using geomorphic indices is essential to comprehend the evolution of a river basin including denudation, surface runoff, subsurface infiltration, differential erosion, lithological variations, possible surface tilting, landslides, and the influence of geological formations and structure. Research in morphometric measurements continues to face many challenges and difficulties despite all the effort carried out. These include the inaccuracy of morphometric measurements and the time it takes to obtain the expected results in large basins. Under such condition, the purpose of the study is to conduct an analysis for the group of indices which includes SL index, transversetopographic symmetry factor, and hypsometry curve along with its integral value in the Mandakini Catchment. Examining the spatial distribution of knickzones has not been well documented, particularly in the Mandakini Catchment; hence, we further analyzed the spatial distribution of knickpoints, channel steepness index, and chi-index along with the longitudinal river profile. Through this analysis, we aim to determine how these indices collectively contribute to the comprehensive characterization of the landscape evolution within the study area and to find the landscape signatures of the uplift by comparing different river profiles. Various knickpoints were found mainly in the upper reaches at higher elevation, validated through aerial imagery and then through detailed field observation. During the field investigation, various geomorphic indicators such as fluvial terraces, entrenched river meandering, active landslides, extensive toe erosion, and waterfalls associated were observed. The study also found out that the places near the Kedarnath, Sonprayag, and Kalimath-Kotma, show high SL index and high steepness index that may correlate with the presence of active thrust and faults.

Structure of the basement of the near-Laptev part of the Eurasian basin according to geological and geophysical data

The near-Laptev part of the Eurasian basin is the area of transition from modern spreading to intraplate rifting. We propose an approach to the construction of a 3D model of the basement of the Laptev Sea part of the Eurasian basin based on the linkage of all currently available geological and geophysical data. The structure of the acoustic basement of the Eurasian basin is characterized by alternating troughs and highs in cross-section. The sparse seismic data do not allow us to directly trace the strike of these structures, but they can be correlated with the linearity established by gravity and magnetic data and related to the sequential opening of the basin. For the Laptev Sea part of the Eurasian basin, where linearity is no longer traceable from magnetic data, we propose a method of determining the strike of the basement structures on the basis of seismic stratigraphic analysis. The new 3D model of the acoustic basement in the studied area provided the basis for the tectonic scheme of the entire Eurasian basin. The model reflects the main stages of basin development: continental rifting up to 56 Ma, normal spreading 56–45 Ma, ultra-slow spreading 45–34 Ma, ultra-ultra-slow spreading 34–20 Ma. The southern part of the study area is overlain by a sedimentary cover with an age of 20 Ma and younger, which is associated with the cessation of spreading here no later than 20 Ma.

Comprehensive Basin Analysis and Petroleum Potential Evaluation of Ayoluengo Oil Field, Basque-Cantabrian Basin, Spain

This study presents a comprehensive basin analysis and petroleum potential evaluation of the Ayoluengo oil field in the Basque-Cantabrian Basin, Spain. Using an integrated approach combining geological, geophysical, and geochemical data, we analyzed the basin's evolution and petroleum system elements. The dataset included 2D and 3D seismic data, well logs, formation tops, and geophysical maps. Our analysis revealed a complex structural framework characterized by salt diapirism and halokinetic structures. Well log interpretation and sequence stratigraphic analysis identified two genetic sequences with associated systems tracts. Four reservoir units were mapped, with the main structural traps related to salt diapirs. Seismic facies analysis highlighted high-amplitude convergent (CBH) and high- and low-amplitude convergent (CBHL) facies as the most promising for reservoir quality. The study identified one play (Jurassic) and two prospects: Lias Limestone (80% geologic chance of success) and Carniolas Dolomite (85% geologic chance of success). Volumetric calculations estimate significant hydrocarbon potential, with STOIIP (Stock Tank Oil Initially In Place) ranging from 3.4 to 4.2 x 10^16 barrels for the Lias Limestone reservoir and 1.26 to 1.56 x 10^16 barrels for the Carniolas Dolomite reservoir.

The collaborative agglomeration of industries and the realization of the digital economy on the green high-quality development of cities

PurposeThis study explores the role of industrial co-agglomeration and digital economy in influencing the green high-quality development of the Yellow River National Cultural Park to provide countermeasures and suggestions for promoting the whole-area high-quality development.Design/methodology/approachThis study is based on panel data from 56 cities from 2010 to 2022. First, a Super-SBM model is built to evaluate green high-quality development. Secondly, location entropy is used to measure industrial co-agglomeration and the entropy weight method is used to measure the digital economy. Finally, the panel Tobit model is used to analyze the impact of industrial co-agglomeration and digital economy on the green high-quality development of Yellow River National Cultural Park.FindingsThis study found that (1) industrial co-agglomeration has a negative implication in green high-quality development, while the digital economy boosts green high-quality development; (2) industrial co-agglomeration is a less critical dependency on the level of development of the digital economy in influencing green high-quality development, while the facilitating effect of the digital economy is more dependent on industrial co-agglomeration and (3) the trend of slow growth in industrial co-agglomeration and digital economy development, with significant regional differences in green high-quality development.Research limitations/implicationsUndeniably, our study has several limitations. Firstly, as the study area only includes some cities in individual provinces, such as Qinghai, this paper only analyzes at the city level, which does not better reflect the differences between provinces; secondly, this study only adopts one method to determine the digital economy. In the future, other methods can be explored to measure digital economy; finally, in addition to the main role of digital economy and industrial co-agglomeration, other factors may also affect the green high-quality development of YRNCP. Future research should introduce other variables to improve the theoretical framework.Practical implicationsFirst, it provides countermeasures and suggestions for promoting the green high-quality development of YRNCP. Second, it helps to implement the new development concept, cultivate the new quality productivity of culture and the tourism industry and promote the green high-quality development of YRNCP. Third, it provides references to improve the management measures and related policies of the YRNCP more accurately and efficiently. Fourth, it helps to build a new development pattern and has important practical significance in promoting the high-quality development of the whole basin, protecting and inheriting the Yellow River Culture and helping the Chinese-style modernization and development, which are of great practical significance.Social implicationsThe research is carried out from the new perspective of industrial co-agglomeration and digital economy, which provides the theoretical basis and reference for solving the problem of green high-quality development of YRNCP. Second, it broadens the research idea of green high-quality development. Third, it quantitatively analyzes the impact of industrial co-agglomeration and digital economy on the high-quality development of YRNCP, deepening the research on the green high-quality development of YRNCP. Fourth, it helps to enrich and improve the theoretical research related to the national cultural park development and has positive significance in promoting the management and innovation of the cultural industry and the construction of related disciplines.Originality/valueThe paper’s findings illustrate the functional relationship of the digital economy and industrial co-agglomeration with green high-quality development and propose countermeasures to facilitate the high-quality development of the Yellow River National Cultural Park.

Tectonic evolution and source rocks development of the super oil-rich Bohai Bay Basin, East China

The Bohai Bay Basin, as a super oil-rich basin in the world, is characterized by cyclic evolution and complex regional tectonic stress field, and its lifecycle tectonic evolution controls the formation of regional source rocks. The main pre-Cenozoic stratigraphic system and lithological distribution are determined through geological mapping, and the dynamics of the pre-Cenozoic geotectonic evolution of the Bohai Bay Basin are investigated systematically using the newly acquired high-quality seismic data and the latest exploration results in the study area. The North China Craton where the Bohai Bay Basin is located in rests at the intersection of three tectonic domains: the Paleo-Asian Ocean, the Tethys Ocean, and the Pacific Ocean. It has experienced the alternation and superposition of tectonic cycles of different periods, directions and natures, and experienced five stages of the tectonic evolution and sedimentary building, i.e. Middle–Late Proterozoic continental rift trough, Early Paleozoic marginal-craton depression carbonate building, Late Paleozoic marine–continental transitional intracraton depression, Mesozoic intracontinental strike-slip–extensional tectonics, and Cenozoic intracontinental rifting. The cyclic evolution of the basin, especially the multi-stage compression, strike-slip and extensional tectonics processes in the Hercynian, Indosinian, Yanshan and Himalayan since the Late Paleozoic, controlled the development, reconstruction and preservation of several sets of high-quality source rocks, represented by the Late Paleozoic Carboniferous–Permian coal-measure source rocks and the Paleogene world-class extra-high-quality lacustrine source rocks, which provided an important guarantee for the hydrocarbon accumulation in the super oil-rich basin.