Basin System Research Articles

Geological storage of CO 2 in Hungary : the overview of storage potential and the role of natural occurrences

The Pannonian basin system, shared by seven Central-Eastern European countries, is one of the most perspective areas of onshore CO 2 geological storage in Europe. In the Hungarian part of the Pannonian basin system, the storage could be realized in depleted hydrocarbon reservoirs and saline aquifers comprising dominantly of Upper Miocene basin filling sediments. The estimated overall potential for CO 2 storage exceeds the 10 3 Mt in case of Hungarian part of the Pannonian basin system. The depleted hydrocarbon reservoirs correspond to this potential with limited, but well-defined capacities. However, saline aquifers represent large but indefinite capacities in the region. Furthermore, the accessibility of hydrocarbon fields is geographically limited in contrast to saline aquifers, which are regionally widespread in the Pannonian basin system. Structures that developed in the basin filling Late Miocene strata may also have been CO 2 rich or pure CO 2 -containing natural reservoirs. These natural laboratories represent a unique opportunity to study long-term processes taking place in the reservoir-CO 2 system and can be used to predict physical and chemical processes that are characteristic for the subsurface development during and after CO 2 injection in depleted hydrocarbon or saline aquifer reservoir.

A review of the Neogene formations and beds in Slovenia, Western Central Paratethys

Neogene sedimentary successions are found in eastern and northeastern Slovenia. Their formation was closely related to the evolution of the western part of the Pannonian Basin System and the Central Paratethys; it was influenced by global transgressive and regressive cycles as well as by global, regional and local tectonics. Several formations and beds were defined within the Neogene sedimentary successions which can be found in three separate areas. The first one includes the formations north of two major fault systems, the Periadriatic Fault System and the Mid-Hungarian Zone, which were associated with the Mura-Zala and the Styrian Basins, respectively. Successions south of these major faults are not formally connected to any of the major basins and developed in two distinct parts: a strip between Tunjice and Kozjansko to the north and the Krško area to the south. From the Egerian to the early Badenian, different areas exhibit different types of sedimentation, whereas from the middle Badenian onwards, sedimentation in different zones is partly comparable, depending on the type of depositional environment. Egerian and Eggenburgian sediments are only found south of the above-mentioned major fault zones, whereas Karpatian sedimentation only occurred north of them. Sediments in both areas are characterized by alternation of shallow marine, brackish and terrestrial sedimentation. In contrast, sedimentary environment in the Badenian evolved from a terrestrial, mainly fluvial environment with alluvial fans, through a transitional stage (delta and lagoon) to a shallow and deep marine environment. The Sarmatian sequences reflect a brackish environment with decreasing salinity and continue into extensive Pannonian delta systems that gradually fill the basins from west to east. The formations that correspond to the Pannonian in the Mura-Zala Basin can be correlated with the formations in the Krško area. The Pliocene is characterized by terrestrial sedimentation with the formation of rivers and lakes in the newly established intramontane basins.

Anthropogenic transformation of socio-ecosystems in the river basin of the Bystrytsia (Ukrainian Carpathians)

Research on the anthropogenic transformation of socio-ecosystems in small river basins allows us to assess the scale of settlement impact and formulate measures for the sustainable development of territories. Settlement impact is reflected in changes in land structure – increase of built-up land and arable land within settlements and a decrease in natural forest and wetland geosystems. Such transformations in the catchment area of small rivers affect water quality reduce river flow, lead to siltation of the riverbed, and often threaten small rivers' existence in general. The Bystrytsia river basin has been inhabited for a long time, but due to the diversity of the relief and different types of nature management in the upper reaches and the mouth, the level of the anthropogenic transformation of socio-ecosystems is different. Anthropogenic transformation within human settlements (socio-ecosystems) was determined by systematic analysis of all factors causing changes. We analysed the historical settlement of the Bystrytsia basin and the current population in 43 settlements. They are home to 27,018 people. We identified the main potential anthropogenic sources of geosystem pollution: farms, landfills waste and untreated discharges from private homes. The anthropogenic load in the Bystrytsia basin began to increase sharply from the beginning of the twentieth century and reached its peak in 1970–1990. Extensive farming since the beginning of the twenty-first century, the expansion of anthropogenic impacts, and new threats caused by global climate change have continued the transformation of socio-ecosystems. Level of transformation of socio-ecosystems increases from the upper reaches to the river's outlet in the middle reaches. The greatest changes occurred in socio-ecosystems with high population density as a result of agricultural load: plowing, drainage melioration, farm work. These are settlements of the lowland part of the basin – Stupnytsia, Horodyshche, Dublyany, Verkhniy Dorozhiv. Indicators correlate with population density and the share of ecologically destabilising lands within settlements: the share of arable land reaches 50%, and together with hayfields and pastures it exceeds 70% of the territory. Forest cover is at the level of 20%. Our analysis helped to formulate measures and recommendations for the balanced use of the basin system of Bystrytsia and minimisation of anthropogenic impact. The studied areas are attractive for the development of tourism and recreation. An important condition is to maintain high quality and sustainability of natural geosystems and compliance with legislation. Key words: anthropogenic impact; basin approach; Bystrytsia River; anthropization; settlement impact.

The changes of the transit denudation in the river basin systems of the Eastern Carpathians

Two river basins were chosen for the research. Both of them are monitored by water levels, water discharge and suspended sediments runoff: the Oriava River (left tributary of the Opir River, the gauging station – Sviatoslav) and the Bystrytsia River (right tributary of the Dnister River, the gauging station – Velyka Ozymyna). Both river basins have similar catchment area, morphometric parameters, but different forestry coefficients and hydro-climatic conditions. By the research the relations between the water discharge, precipitation and suspended sediments runoff have been analyzed. The water discharge dynamics features testify about difference in the morphometric conditions of the river beds. The matching of the year precipitation and water discharges testifies about determinative role of the precipitation irregularity in the surface runoff forming. The mean annual suspended sediments runoff modules in the Bystrytsia catchment 2.3 times larger than in the Oriava catchment. But this data is not enough to conclude about lesser transit denudation and slope erosion in the Oriava basin. Therefore, with the aim of preliminary assessment of the relations between the analyzed parameters and influence of different factors including human activities the series of twin graphs for many years dynamics of the parameters. The differences in sediments granulometry of the two river systems have been ascertained. The disturbed equidistance between the graphs of testifies on some factors influences which is more characteristic for the Bystrytsia river than Oriava. This fact concords with the conclusions of the scientists concerning relatively higher level of man-made affection of the Bystrytsia River basin. Ascertaining of these factors and their quantitative assessment are the perspective task for the next research stages. The investigations also confirm the determinative influence of the granulomentric composition of sediments on the relations between the water discharge and suspended sediments runoff in the researched river systems. Since the portion of the smallest fractions of the suspended sediments is considerably bigger in the abounding in water years, this fact confirms the conclusion about high level slope erosion in such years. Absence of the fractions more than 0.5 mm in the suspended sediments load in the Oriava River may be caused by the cascade of the dams and ponds of the trout farm in its main river course. At the same time it can partly explain the higher parameters of the suspended sediments runoff in the Bystrytsia (Velyka Ozymyna) in comparison to the Oriava (Sviatoslav). To confirm such conclusions it is necessary to match and analyze the granulomentric composition of the not only suspended sediments, but also bottom ones and their transition through the river bed. Key words: river system; river catchment; water discharge; suspended sediments runoff; Bystrytsia River; Oriava River.

The Pannonian Stage: Stratigraphy and geo-energy resources

The youngest regional chronostratigraphic unit of the Central Paratethys, the Pannonian Stage, is benchmarked by the deposits of Lake Pannon, containing a highly endemic, Caspian-type biota, and the sediments of adjacent deltas and fluvial plains. The Pannonian Stage also includes various freshwater lake deposits and vast volcanic formations, especially in the northern and eastern margins of the Pannonian Basin system. The Pannonian correlates with the Tortonian, Messinian, Zanclean and Piacenzian Stages, thus represents 9 Myr between 11.6 and 2.6 Ma. The Pannonian is divided into biochronostratigraphic units by the application of mollusc and dinoflagellate biochronozones in the Lake Pannon deposits and mammal biozones in the freshwater sediments. The Pannonian Stage is a leading geo-energy provider in terms of hydrocarbons and lignite. Prolific oil and gas reservoirs occur in both the deep-water and deltaic sand bodies in the central part of the Pannonian Basin, which is a highly mature exploration area. The practically inexhaustible lignite resource of the Pannonian Stage has been mined or is still being mined in the basin margins in all ten countries of the Pannonian Basin system.

A NEW TURBIDITE FACIES TRACT SCHEME INCLUDING SUPERCRITICAL AND TRANSITIONAL SAND–MUD FLOWS: AN OUTCROP PERSPECTIVE FROM MEDITERRANEAN-TYPE FORELAND BASINS

The studies carried out on tectonically-confined turbidite systems in Mediterranean-type foreland basins have shown that these deposits can be dominated by supercritical flows and by their transformation into subcritical and/or transit ional (mud-sand) flows. In these confined turbidite systems, flow deceleration is favoured especially by morphologies transversal to paleocurrents, e.g., slope breaks or adverse slopes that can vary in scale from regional tectonic structures to depositional features such as thick mass-transport complexes and lobes. Based on data of more than fifty years of outcrop studies in foreland and wedge top basins, a new facies tract scheme is presented that includes the occurrence of supercritical flow deposits and hybrid event beds in turbidite successions. A review of the main turbidite facies schemes available in the literature is given, and detailed field examples of the Apennine and Alpine (Peira Cava) foreland basins are given that demonstrate the effect of basin morpholo gy on the type of facies tracts. The concept of flow efficiency is revisited as sediment transport depends not only on flow behaviour but also on basin size and basin-floor morphology (e.g., large foredeeps are characterised by facies that reflect high-efficiency, whereas small piggy back basins are characterised by facies related to low-efficiency transport).

The September 21, 2020 (Mw = 5.6) Bystraya Earthquake at the South-Western Flank of the Baikal Rift Zone: a Milestone in Macroseismology of Eastern Siberia

The article presents analysis of macroseismic data on the September 21, 2020 (Mw = 5.6) Bystraya earthquake, which occurred in the eastern part of the Tunka basins system on the southwestern flank of the Baikal rift zone. Macroseismic data were collected mainly through an Internet questionnaire posted on the website of the Baikal Branch of the Geophysical Survey, Russian Academy Sciences. A total of 3013 eyewitness responses were collected, which is currently an unprecedented number in the entire history of macroseismic observations in the Baikal region. In total, we collected data for 263 Intensity Data Points. The maximal shaking intensity (VI–VII MSK-64) was observed in the Bystraya village and the Kultuk settlement. The shaking intensity V MSK-64 was noted at a distance of up to ∼180 km; intensity IV MSK-64 was recorded at a distance of up to ∼550 km. Analysis of data on the Bystraya earthquake revealed significantly lower attenuation compared to that expected from the regional macroseismic equation. Due to the large volume of macroseismic data collected, as well as the high efficiency of the data collection method used, the Bystraya earthquake can be considered an important milestone in macroseismic research in East Siberia.

Hydrocarbon generation in the onshore and offshore of the Austral and Malvinas basins based on 3D petroleum system modelling

The Austral and Malvinas basins are prolific oil and gas provinces, estimated to contain a significant proportion of undiscovered hydrocarbon reserves in the South Atlantic. A three-dimensional basin and petroleum system model (3D BPSM) is presented to visualize the complex deformation history which impacted in the volumes of generated hydrocarbons from the Lower Cretaceous source rock (LC-SR) in fold-and-thrust belt (FTB) regions through geological time. Organic geochemistry and maceral analysis obtained from samples from 28 wells were incorporated to 3D BPSM to evaluate the source rock potential from the Austral to Malvinas basins. The LC-SR contains a type II to type II–III kerogen with most samples showing a regular to good (>1%), and in few cases, excellent (>4%) TOC contents in both basins. Modelling results show higher source rock maturities (dry gas window) and kerogen transformation that occurred towards the fold-and-thrust belt regions, where deeper burial conditions were reached. A general decrease of maturity is observed towards the foreland regions of both basins. From Late Cretaceous large volumes of hydrocarbons were generated and expelled in fold and thrust belt regions of Austral and Malvinas basins. The main phase of hydrocarbon generation occurred during the Eocene, when the LC-SR reached the maximum burial, especially in the Fuegian-FTB. Hydrocarbon generation and expulsion continue to the present, particularly in the kitchen located in the eastern sector of the Malvinas Basin.

An integrated approach to characterize diabase sills in Parnaíba Basin, based on geochemical data, cuttings description, and well logs interpretation

Igneous rocks play a fundamental role in the formation and evolution of petroleum systems in several basins around the world. In the Parnaíba Basin, northestern Brazil, the diabase sills and dikes, which compound the Mosquito and Sardinha formations, contribute as a thermal source for an unconventional hydrocarbon generation, as well as providing trap and seal for the petroleum system. To understand these intrusions, we propose a methodology to identify the igneous intrusions in well-logs and interpret their compositional variations. The methodology is based on detailed descriptions of cuttings, X-ray fluorescence (XRF), X-ray diffractometry (XRD) and well logs, such as Gamma Ray (GR), Density (RHOZ) and Photoelectric Factor (PEFZ), from six exploratory wells drilled in the main gas-producing area of the Parnaíba Basin. The intrusions present in these wells were identified through the Igneability Feature and classified based on the GR curve as either “Barriguda” or “Caixote” patterns. The “Barriguda” intrusions show variations in the well logs (GR, RHOZ and PEFZ) along their vertical section, as well as variations in aluminum, calcium, potassium, zirconium, iron, titanium, magnesium, nickel and chromium values, evidencing a great textural and mineralogical variation, confirmed by the mineralogical results of XRD. Data interpretation suggests that the “Barriguda” intrusions are characterized in distinct electrofacies- and chemiofacies that represent an internal variation from top to base, related to magmatic differentiation processes.

Analysis of Hydrocarbon Enrichment in Tight Sandstone Reservoirs in the Eastern Baiyun Depression

Based on the special geological background of the east and north slopes of the Baiyun Depression, the development conditions of Paleogene structure–lithology traps, the development conditions of high-quality reservoirs and the difficulty in characterizing the distribution characteristics are studied in this paper. It is concluded that the eastern Baiyun is located on the Baiyun–Liwan continental–oceanic large-scale intershell separation system, with a complex tectonic background and a tectono-sedimentary pattern of “fault and uplift interlocking and uplift and depression interphase”. The palaeo source sink system of the low bulge in the east of Yundong is restored, the favorable position of reservoir collective development and the favorable characteristics of reservoir–cap assemblage are clarified, and the paleo-geomorphology and sedimentary filling evolution law are clarified. Guided by the drive of oil and gas accumulation, three types of large and medium-sized structure–stratigraphic traps have been implemented in the eastern Baiyun system, including the convex inclined end, the restricted fault gully and the magmatic floor intrusion, and the corresponding oil and gas accumulation models have been perfected. By studying the structure, source and sink system and trap characterization of the eastern Baiyun basin, the development conditions and exploration direction of the large and medium-sized Palaeogene traps are systematically summarized.

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 the quantification of 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 sub-basins 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 depocentres, sourced by exhumed footwalls and from the neighbouring orogens. The overall post-rift sediment progradation is influenced by inherited bathymetries from the preceding syn-rift stage and by enhanced differential vertical motions.

The Segmented Multi‐Source Sediment Routing System on the Hangingwall Dipslope of the Xihu Depression, East China Sea Shelf Basin: Insights From Palaeogeomorphology, U–Pb Ages and Heavy Minerals

ABSTRACTCoeval input systems in rift basins may interact with each other to form a segmented multi‐source sediment routing system. Importantly, its division into proximal zones, where a single source dominates, and interaction zones, where multiple sources mix, enables the interactions between input systems to be characterised. Here, we exploit this conceptual framework to revisit the middle Eocene–early Oligocene hangingwall dipslope of the Xihu depression in the East China Sea Shelf Basin, where extensive 3D seismic data, detrital zircon U–Pb ages and heavy mineral compositions are available. We first combined palaeogeomorphological and sedimentological features with age signatures to distinguish three areas: the northwestern area was identified for its proximity to the Haijiao uplift and invariably high proportions of Palaeoproterozoic ages (41%–54%); the southwestern area adjacent to the Yushan uplift was distinct for enriched Cretaceous‐aged zircons (36%) and the transition area in between was characterised by its remoteness to both uplifts, an embayed geometry and mixed age signatures that are not identical to any individual input. These spatial variations support the segmented framework for the multi‐source system, with the northwestern and southwestern areas representing two palaeo‐input systems and the transition area as their interaction zone. In this context, we then used mixture models to determine spatio‐temporal variations in the mixing proportions of the two palaeo‐input systems. The zircon‐based results indicate that the mixing proportion sustained from the middle to the late Eocene, during which the basin was in the late syn‐rift stage and marine environments. This is corroborated by heavy mineral composition that shows only minor changes. We interpret the roughly sustained mixing proportions as reflecting both the spatially uniform nature of broad subsidence and the strong tidal processes that ‘erased’ the effects of avulsions. In contrast, a clear provenance shift in both zircon ages and heavy minerals occurred from the late Eocene to the early Oligocene, coinciding with a transition to the tectonic inversion stage and a shift towards non‐marine environments. The provenance shift, together with the southward expansion of the axial drainage, likely represents the sedimentary response to the southward decreasing inversion magnitude of the Yuquan Event. In addition, we hypothesize that in the absence of strong tides, avulsions might have controlled the mixing proportion, particularly over short timescales. Ultimately, this study demonstrates the segmented multi‐source framework, if properly incorporated, can provide key insights into dipslope sedimentation.

REVIEWS OF PERSPECTIVES ON CONTEMPORARY APPROACHES AND TECHNIQUES IN FLUVIAL SYSTEMS EVALUATION AND MANAGEMENT

This paper reviews fluvial geomorphology perspectives and methodologies for environmental sustainability by exploring and discussing major concepts, themes, and methodologies. To meet the multidimensional aspect of fluvial geomorphology research, multidimensional approaches are now used. Fluvial geomorphology examines river channel morphology and how it is shaped by fluid flows interacting with erodible or resistant boundaries. Understanding equilibrium conditions and thresholds is key. A systems perspective is needed - any river segment is influenced by upstream and downstream conditions as part of an integrated drainage basin system. Field surveys, mapping, remote sensing, and GIS provide important morphological data on river planform, cross-sections, longitudinal profile features, sediment characteristics, etc. Statistical analysis helps detect spatial patterns and trends. Assessing channel changes over long periods is often necessary to fully understand contemporary fluvial processes and forms. Sediment storage and release causes significant time lags. Major human impacts include land use changes affecting hydrology, sediment budgets, channel boundaries; and infrastructure interrupting continuity. Sustainable management requires addressing root causes. Watershed level processes like water balances, erosion patterns, etc. strongly influence fluvial systems - coordinating river channel and upland catchment interventions is key. Models like SWAT, MIKE-SHE, and ANSWERS simulate hydrological processes but have limitations. They require robust spatial datasets spanning geology, topography, land use, climate, etc. Overall, a multidimensional, scale-conscious, historically contextualized assessment framework is required for evaluating fluvial systems. The review highlights techniques and datasets for such integrated diagnosis.

Tectonic evolution of the early permian Junggar basin: Insights into a foreland basin shaped by lithospheric folding

Foreland basins are shaped by the sedimentary architecture and lithospheric flexure due to the sediment load, slab pull, orogenic growth, and asthenospheric mantle flow. However, it is challenging to differentiate foreland basins from rift basins due to the destructive effects of multiphase orogenesis. Situated at the core of the western Central Asian Orogen Belt, the Junggar Basin holds vital clues regarding the closure of the Paleo-Asian Ocean. There is debate regarding whether it was a compressional foreland basin or an extended rift after the closure of the surrounding oceans. Furthermore, uncertainties persist regarding the fate of the residual oceanic crust and the precise tectonic processes during the collision of the ocean-arc-continent system. Understanding the basin's style during the early Permian period is crucial for deciphering its dynamic tectonic history. This study leverages regional seismic data to reevaluate the overall structure of the Junggar Basin, providing insights into its tectonic context and the mechanisms of intraplate deformation during the early Permian period. The findings reveal significant early Permian deformation features characterized by varying strata thicknesses and unconformities, signifying continuous tectonic activity during deposition. The western and southern depressions that developed from the late Carboniferous to early Permian are in keeping with compressional dynamics and reflect a foredeep basin, while the central uplift corresponds to a forebulge. This study posits that the observed foreland basin system was shaped by lithospheric flexure at the end of the late Carboniferous and lithospheric buckling in the early Permian, which contributed to the creation of uplifted Mosuowan-Baijiahai forebulge in the interior. The Junggar Basin featured a convergent dynamic environment, although the surrounding orogen transitioned into a postcollisional orogen in the Central Asian Orogenic Belt during the early Permian.

Stratigraphic overview of the Neogene Transylvanian Basin, Romania

Although the Transylvanian Basin is often referred to as part of the Miocene Pannonian Basin System, we point out important tectonic and sedimentary differences reflected in the stratigraphy. The Neogene of the Transylvanian Basin can be split into two tectonic megasequences: Lower Miocene and Middle to Upper Miocene. The Early Miocene onset of the back-arc extension in the Pannonian Basin was not observed in the Transylvanian Basin, where shallow to deep-marine sediments were deposited in a flexural basin. Diverse types of facies developed in the continental (e.g. Sânmihai) and marine (e.g. Coruș, Chechiș, Hida) Lower Miocene formations. Although these are poorly constrained to the standard biostratigraphy, recent 87 Sr– 86 Sr data support their poor correlation with the Burdigalian. The Middle Miocene extension in the Transylvanian Basin is very weak compared with that in the Pannonian Basin. As the high-resolution Middle Miocene regional biostratigraphy of the Badenian and Sarmatian was calibrated by magnetostratigraphy and radiometric dating of the volcanic tuffs up to the Serravallian/Tortonian boundary, the influence of the regional tectonics on the basin's evolution and stratigraphy can be better understood. The regional tectonics produced a progressive basin isolation starting with the late part of the Middle Miocene. The uplift of the Carpathians isolated the basin at the beginning of the Pannonian and initiated the fan delta, lacustrine and fluvial sedimentation. The basin was rapidly uplifted and eroded while post-extensional subsidence was still ongoing in the Pannonian Basin. Endemic fossil assemblages allow only regional-scale correlations for this interval. The uppermost part of the stratigraphic record is represented by the volcano-sedimentary formations generated by the late evolution of the Eastern Carpathians. The sedimentation and subsidence pattern of the Transylvanian Basin reflect the effect of retreating subduction zone in the Eastern Carpathians.

The Styrian Basin: an overview with new insights from seismic data

The Neogene Styrian Basin is the westernmost sub-basin of the Pannonian Basin System. The last comprehensive studies on the basin were published in the last millennium. This overview of the current understanding of basin evolution is based on the re-interpretation of partly unpublished reflection seismic data and a wealth of sedimentological and stratigraphic studies performed during the last 25 years. Reflection seismic data indicate the presence of a major east-to-southeast-dipping detachment horizon within the pre-Neogene basement reflecting high-strain upper crustal extension during the early Miocene syn-rift stage of basin evolution. Fault block rotations caused subsidence in several sub-basins, which developed often with marked asymmetric geometry. The maximum basin depth exceeds 4 km (Gnas Basin). Syn-rift deposits include thick alluvial fan and fan delta sediments overlain in the basin centre by deeper marine pelitic rocks. Subduction-related magmatic activity commenced during the syn-rift stage and continued into the middle to late Miocene post-rift stage. Syn- and post-rift sediments are separated by the middle Miocene ‘Styrian Unconformity’. Shallow marine sedimentation, controlled by third- and fourth-order sea-level variations, prevailed during the early post-rift stage. The final stage of basin evolution was characterized by differential surface uplift, erosion and Pliocene–Pleistocene basaltic magmatism.

Environmental impacts and nitrogen-carbon-energy nexus of vegetable production in subtropical plateau lake basins.

Vegetables are important economic crops globally, and their production has approximately doubled over the past 20 years. Globally, vegetables account for 13% of the harvested area but consume 25% of the fertilizer, leading to serious environmental impacts. However, the quantitative evaluation of vegetable production systems in subtropical plateau lake basins and the establishment of optimal management practices to further reduce environmental risks are still lacking. Using the life cycle assessment method, this study quantified the global warming, eutrophication, acidification, and energy depletion potential of vegetable production in a subtropical plateau lake basin in China based on data from 183 farmer surveys. Our results indicated that vegetable production in the study area, the Erhai Lake Basin, was high but came at a high environmental cost, mainly due to low fertilizer efficiency and high nutrient loss. Root vegetables have relatively high environmental costs due to the significant environmental impacts of fertilizer production, transportation, and application. A comprehensive analysis showed that the vegetable production in this region exhibited low economic and net ecosystem economic benefits, with ranges of 7.88-8.91 × 103 and 7.35-8.69 × 103 $ ha-1, respectively. Scenario analysis showed that adopting strategies that comprehensively consider soil, crop, and nutrient conditions for vegetable production can reduce environmental costs (with reductions in global warming potential (GWP), eutrophication potential (EP), acidification potential (AP), and energy depletion potential (EDP) by 10.6-28.2%, 65.1-73.5%, 64.5-71.9%, 47.8-70.4%, respectively) compared with the current practices of farmers. This study highlighted the importance of optimizing nutrient management in vegetable production based on farmers' practices, which can achieve more yield with less environmental impacts and thereby avoid the "trade-off" effect between productivity and environmental sustainability.

Morphometric Analysis of the Pahang River Basin and Its Sub Basin System at Pahang State, Peninsula Malaysia

Morphometric Analysis of the Pahang River Basin and Its Sub Basin System at Pahang State, Peninsula Malaysia

A synproportionation-controlled hybrid hydrothermal mineralization system in the Okinawa Trough

Hybrid hydrothermal systems, in which both water-rock reactions and magmatic fluids contribute to sulfide mineralization, have recently been reported in some submarine arcs and mature back-arc basins. Owing to their high mineralization efficiency, hybrid hydrothermal systems have attracted significant attention from geologists. This study provides first clues for the identification of a novel hybrid hydrothermal system (synproportionation-controlled instead of the more common disproportionation-controlled) in the Tangyin field, Southern Okinawa Trough. The studied samples are native sulfur-type precipitates, primarily composed of elemental sulfur with minor sulfide disseminations. The distinct crystallization conditions and S isotope compositions of elemental sulfur and sulfide disseminations indicate their different genesis. The S in sulfide disseminations (δ34S = −2.7 to 1.6 ‰) is derived from water-rock reaction and subsequently influenced by fluid phase separation, which is further demonstrated by the trace element contents of pyrite (low Tl/Pb, Sb/Pb, Te/As, Te/Sb ratios). In contrast, the elemental sulfur (δ34S = 3.9 to 4.3 ‰) is formed by the synproportionation of magmatic SO2 and hydrothermal H2S from the boiled liquid. A simple two-component mixing calculation indicated that the contributions of the water-rock reactions and magmatic fluids to the Tangyin hydrothermal system were approximately equal. The higher temperature (> 350 °C) and oxygen fugacity conditions may be the key factors for the development of a synproportionation-controlled hybrid hydrothermal system in the Tangyin field. Hydrothermal systems in back-arc basins exhibit higher sulfide accumulation rates than those in mid-ocean ridges; this may be attributed to the prevalence of hybrid hydrothermal vents in back-arc settings.

Current Geological Issues and Future Perspectives in Deep-Time Source-to-Sink Systems of Continental Rift Basins

Current Geological Issues and Future Perspectives in Deep-Time Source-to-Sink Systems of Continental Rift Basins