Broad Scale Research Articles

Environmental Filters Structure Cushion Bogs' Floristic Composition along the Southern South American Latitudinal Gradient.

The environmental filtering hypothesis predicts that abiotic factors restrict communities by selecting species capable of survival and persistence under specific conditions, resulting in variations in beta diversity, phylogenetic clustering, and niche differentiation among communities when studying environmental gradients. Cushion bogs and high-altitude wetlands along the Andes display homogeneous flora contrasting with zonal vegetation. Despite being influenced by microclimatic conditions, these ecosystems are subject to diverse environmental effects. Here, we test the environmental filtering hypothesis on the structure of cushion bog communities along a broad-scale latitudinal gradient from 15° S to 42° S. We analyzed 421 bogs and 293 species across three macroclimatic regions with distinct summer, winter, and transitional arid rainfall regimes. Using variance partitioning and membership-based regionalization models, we examined the impacts of climatic, edaphic, and spatial variables on beta diversity. We also assessed species' niche overlap and the influence of environmental filters on the communities' phylogenetic diversity. Results show that species turnover and niche overlap vary with macroclimatic differences, delineating three distinct regions. Notably, phylogenetic clustering in the driest part of the gradient (23° S-24° S) highlights the impact of environmental filtering. Aridity and temperature variations at a broad scale serve as environmental filters shaping the composition of bog communities across southern South America.

Navigating Brain Metastases: Unveiling the Potential of 3-Tesla Intraoperative Magnetic Resonance Imaging.

Intraoperative magnetic resonance imaging (iMRI) has witnessed significant growth in the field of neurosurgery, particularly in glioma surgery, enhancing image-guided neuronavigation and optimizing the extent of resection (EOR). Despite its extensive use in the treatment of gliomas, its utility in brain metastases (BMs) remains unexplored. This study examined the effect of iMRI on BM resection. This retrospective study was conducted at the neurosurgical center of the University Hospital of the Technical University of Munich and involved 25 patients with BM who underwent resection using 3-Tesla iMRI between 2018 and 2022. Volumetric measurements of the resected contrast-enhancing metastases were performed using preoperative, intraoperative, and postoperative MRI images. The Karnofsky Performance Score (KPS) and neurological status of the patients were assessed pre- and postoperatively. Local recurrence and in-brain progression were reported in patients who underwent follow-up MRI at 3 and 6 months postoperatively. In this cohort (n = 25, mean age 63.6 years), non-small-cell lung cancer (NSCLC) was the most common origin (28%). The mean surgical duration was 219.9 min, and that of iMRI was 61.7 min. Indications for iMRI were primarily associated with preoperative imaging, suggesting an unclear entity that is often suspicious for glioma. Gross total resection (GTR) was achieved in 21 patients (84%). Continued resection was pursued after iMRI in six cases (24%), resulting in an improved EOR of 100% in five cases and 97.6% in one case. Neurological status postoperatively remained stable in 60%, improved in 24%, and worsened in 16% of patients. No wound healing or postoperative complications were observed. Among the thirteen patients who underwent follow-up MRI 3 months postoperatively, one patient showed local recurrence at the site of resection, and seven patients showed in-brain progression. Of the eight patients who underwent a 6-month follow-up MRI, two showed local recurrence, while three exhibited in-brain progression. The observed favorable profiles of GTR, coupled with the notable absence of wound-healing problems and acute postoperative complications, affirm the safety and feasibility of incorporating iMRI into the neurosurgical workflow for resecting BM with specific indications. The real-time imaging capabilities of iMRI offer unparalleled precision, aiding meticulous tumor delineation and informed decision-making, ultimately contributing to improved patient outcomes. Although our experience suggests the potential benefits of iMRI as a safe tool for enhancing EOR, we acknowledge the need for larger prospective clinical trials. Comprehensive investigations on a broader scale are imperative to further elucidate the specific indications for iMRI in the context of BMs and to study its impact on survival. Rigorous prospective studies will refine our understanding of the clinical scenarios in which iMRI can maximize its impact, guiding neurosurgeons toward more informed and tailored decision-making.

Climate and Land Use Changes Impact the Future of European Amphibian Functional Diversity

Climate and land use changes drive shifts in species distributions, causing variations in species richness. Yet the influence of shifts in species distributions on functional diversity at broad spatial scales remains uncertain. Here, we explored the potential effect of climate and land use changes on the functional diversity of European amphibian assemblages from the present to 2050, along with their effect on species richness. We performed species distribution modelling using a scenario of climate and land use change to estimate current and future potential distributions of 73 species. We estimated functional diversity using morphological and ecological functional traits. Our results highlight the intricate effects of climate and land use changes on taxonomic and functional diversity of amphibians. A climate-induced northward expansion of amphibians is anticipated, with temperature, precipitation, and forest cover prominently shaping future assemblages. Species expected to have shrinking ranges (n = 35) tend to mature sexually at a later age, produce fewer offspring per reproductive event, and live at higher maximum altitudes compared to species expected to expand (n = 38). Furthermore, trait composition changes are expected to exceed predictions based solely on species richness. These changes will vary geographically, with northern regions likely experiencing substantial increases in functional richness and functional redundancy, i.e., the coexistence of species with similar functional roles. Our findings underscore that functional diversity changes might serve as an early warning signal to assess human impacts on biodiversity.

Tackling global biogeography and drivers of soil microbial dehalogenation traits and taxa: Insights from metagenomic profiling based on a curated dehalogenase database

To identify microbial resources for dehalogenation, develop effective remediation strategies, and reveal their significance in “One Health”, it is crucial to understand the occurrence, distribution, and drivers of soil dehalogenation functional traits and taxonomy groups at a broad scale, which is currently not well understood. To address the gaps, we characterized the biogeography of both dehalogenation traits and taxa assigned to six dehalogenation pathways, by metagenomic profiling global 4821 soils from eight habitats, based on a manually curated dehalogenase database (DhgaseDB). We found dehalogenation genes and microbes assigned to different pathways are everywhere, but varied consistently across habitats. The similarity of dehalogention traits and taxa composition declines with geographic distance, and that patterns are strongly correlated with geo-environmental factors. We identified anthropogenic organohalide pesticide inputs as the most influential factor on dehalogenation gene abundance, while soil properties, particularly pH, exert a larger impact on dehalogenation taxa diversity. Ultimately, we generated predictive maps of soil dehalogenation gene abundance and taxa diversity for the first time, highlighting the microbial dehalogenation hotpots in East Asia, Australia, Southern Africa, and coastal regions. Collectively, our study highlights the significant role of various microbial dehalogenation processes in organohalide biotransformation and environmental microecology, providing the necessary methodological basis for a deeper comprehension of the underlying mechanisms, thereby contributing to the advancement of tailored strategies for organohalide remediation.

Characterizing offshore polar ocean soundscapes using ecoacoustic intensity and diversity metrics.

Polar offshore environments are considered the last pristine soundscapes, but accelerating climate change and increasing human activity threaten their integrity. In order to assess the acoustic state of polar oceans, there is the need to investigate their soundscape characteristics more holistically. We apply a set of 14 ecoacoustic metrics (EAMs) to identify which metrics are best suited to reflect the characteristics of disturbed and naturally intact polar offshore soundscapes. We used two soundscape datasets: (i) the Arctic eastern Fram Strait (FS), which is already impacted by anthropogenic noise, and (ii) the quasi-pristine Antarctic Weddell Sea (WS). Our results show that EAMs when applied in concert can be used to quantitatively assess soundscape variability, enabling the appraisal of marine soundscapes over broad spatiotemporal scales. The tested set of EAMs was able to show that the eastern FS, which is virtually free from sea ice, lacks seasonal soundscape dynamics and exhibits low acoustic complexity owing to year-round wind-mediated sounds and anthropogenic noise. By contrast, the WS exhibits pronounced seasonal soundscape dynamics with greater soundscape heterogeneity driven in large part by the vocal activity of marine mammal communities, whose composition in turn varies with the prevailing seasonal sea ice conditions.

GIS based geostatistical modelling and trends analysis of groundwater quality for suitable uses in Dhaka division

Preserving the quality of groundwater has become Bangladesh’s primary challenge in recent years. This study explores temporal trend variations in groundwater quality on a broader scale across 18 stations within the Dhaka division over 35 years. The data set encompasses an analysis of 15 distinct water quality parameters. Modified Mann-Kendal, Sens Slope and Mann-Kendal tests were performed to determine the trend’s variation and slope. In addition, the spatial–temporal changes in the quality of groundwater are studied through Geographic Information System (GIS) mapping and Piper diagram was applied to identify the unique hydrochemical properties. This is the first study conducted on this area using various trends analysis and no in-depth study is available highlighting the trends analysis of groundwater quality on a larger magnitude. In contrast, the correlation matrix reveals a high association between Mg2+ and SO42−, Na+ and Cl− that affects salinity and overall hardness at the majority of sites. The Piper diagram also demonstrates that the groundwater in Madaripur Sadar has major salinity issues. The analysis reveals a distinctive dominance of bicarbonate (HCO3−) ions across all sampling stations, with (HCO3−) equivalent fractions consistently ranging from 0.70 to 0.99 which can cause a significant impact on groundwater uses. This extensive analysis of long-term groundwater quality trends in the Dhaka Division enables researchers to comprehend the overall transition of groundwater quality for hardness related complications in future. Moreover, it can be a baseline study considering the valuable implications and future steps for sustainable water resource management in this region.

Transitions between colour mechanisms affect speciation dynamics and range distributions of birds.

Several ecogeographical 'rules' have been proposed to explain colour variation at broad spatial and phylogenetic scales but these rarely consider whether colours are based on pigments or structural colours. However, mechanism can have profound effects on the function and evolution of colours. Here, we combine geographic information, climate data and colour mechanism at broad phylogenetic (9,409 species) and spatial scales (global) to determine how transitions between pigmentary and structural colours influence speciation dynamics and range distributions in birds. Among structurally coloured species, we find that rapid dispersal into tropical regions drove the accumulation of iridescent species, whereas the build-up of non-iridescent species in the tropics was driven by a combination of dispersal and faster in situ evolution in the tropics. These results could be explained by pleiotropic links between colouration and dispersal behaviour or ecological factors influencing colonization success. These data elucidate geographic patterns of colouration at a global scale and provide testable hypotheses for future work on birds and other animals with structural colours.

Testing the form-function paradigm: body shape correlates with kinematics but not energetics in selectively-bred birds

A central concept of evolutionary biology, supported by broad scale allometric analyses, asserts that changing morphology should induce downstream changes in locomotor kinematics and energetics, and by inference selective fitness. However, if these mechanistic relationships exist at local intraspecific scales, where they could provide substrate for fundamental microevolutionary processes, is unknown. Here, analyses of selectively-bred duck breeds demonstrate that distinct body shapes incur kinematic shifts during walking, but these do not translate into differences in energetics. A combination of modular relationships between anatomical regions, and a trade-off between limb flexion and trunk pitching, are shown to homogenise potential functional differences between the breeds, accounting for this discrepancy between form and function. This complex interplay between morphology, motion and physiology indicates that understanding evolutionary links between the avian body plan and locomotor diversity requires studying locomotion as an integrated whole and not key anatomical innovations in isolation.

Recent advances on hydrogen generation based on inorganic metal oxide nano-catalyst using water electrolysis approach

Abstract Today world is looking for a cheap, environment friendly and efficient substitute of fossil fuel. Because due to large consumption of the fossil fuels on daily basis in whole world, emission of hazardous gases have produced lethal effects on human being. In this scenario hydrogen energy has emerged in form of clean, renewable and more efficient energy. Now the key challenge is that efficient production of the green hydrogen at commercial scale to meet demand of hydrogen. The electrolysis of water is the best pathway to achieve efficient hydrogen production. For this purpose the synthesis and improvement of low cast, active as well as stable catalysts or electrolysis is prerequisite for hydrogen production by electro-catalytic method for splitting of water. Main focus of this review is that, how we can perform the electrolysis of water by various techniques using novel methods especially electro-catalysts in term of activity, efficiency, large surface area, porosity, and stability. This will be performed by the method of two-half cell reaction one is the Hydrogen Evolution Reaction (HER) other one Oxygen Evolution Reaction (OER), where reaction proceeded in both medium acidic as well as alkaline phases. Particular attention is given to produce green clean hydrogen production from usable water and its physical and chemical storages for further uses for the support of human sustainability. Basically the recent strategy is to prepare, design and development of nanoscale materials/composite with non-noble metals and with also nanostructured with noble-metals will be discussed in this approach. The increased efficiency and utility have been the focal points of the use of diverse materials from different classes. To increase the electro-catalytic efficiency in OER and HER, we will discuss about new analyses methods and insights into studying the chemical compositions, shapes, surface area, porosity, and synergy of catalysts and the active sites of nanostructured electro-catalysts. This review will further provide the picture of current state of developments as well as recent progress for mechanized efficient production of clean hydrogen (i.e., HER) from water by electrocatalytic method using various nanoscale materials in a broad scale.

Let’s measure it: An approach of high-resolution estimates of bottom fixed net fishing effort at national level

Fisheries are one of the most important food sources for human consumption whilst being amongst the most impacting and extractive activities happening within the marine environment, which makes it imperative to properly manage this activity. To improve fisheries management, the precise quantification of fishing effort is of the outmost importance. Yet, present methods for effort estimation, especially at broad scales, are hampered by difficulties in data access and usually rely on coarse effort metrics or on costly data collection for quantifying fishing effort with higher resolution. In the present work, we propose an approach of high-resolution fishing effort estimates of net fishing, as length of nets operated by a given fleet, at the national level. It relies on sampling of effort, derived from classified and easy to access vessel tracking data – AIS, and fishery dependent data – logbook and landings data. The proposed methodology combines trip-based effort estimates, derived from AIS data, as a foundation to extrapolate the total fishing effort, through the number of fishing trips linked to official landings and logbook data. It is estimated that in the years from 2014 to 2020 an average of 180 200 km of static nets (gillnets and trammel nets), which corresponds to approximately 4.5 and 210 times the lengths of the equator and the Portuguese Atlantic coastline respectively, are used in Portuguese mainland waters each year, by a fleet of slightly more than 100 vessels. The presented methodology allows to quantify and study the variation of the nominal fishing effort, at country level, with a higher resolution than what is usually used and at very low cost. We argue that such methodologies need to be developed and explored in order to have better and more comprehensive estimates of fishing effort which will contribute and improve the sustainable management of fisheries and the marine environment.

Environmental and anthropogenic factors mediating the functional connectivity of the mesquite lizard along the eastern Trans-Mexican Volcanic Belt.

Functional connectivity, the extent to which a landscape facilitates or impedes the dispersal of individuals across the landscape, is a key factor for the survival of species. Anthropogenic activities, such as urbanization, agriculture and roads, negatively impact functional connectivity of most species, particularly low-vagility species like lizards. Here, we examine how a landscape modified by anthropogenic activities affects the functional connectivity, at both broad and fine scales, of a widely distributed generalist lizard Sceloporus grammicus in the eastern Trans-Mexican Volcanic Belt, Mexico. We estimated for the first time the species' genetic structure, gene flow and functional connectivity in agricultural and forest zones using genomic data, a comprehensive landscape characterization and novel methods including gravity models. Our results showed not only marked genetic differentiation across the study region but also that functional connectivity is maintained for tens of kilometres despite S. grammicus low vagility. Specifically, we found that substrate and air temperature facilitated connectivity over broad and fine scales, respectively, while agricultural cover, relative humidity and slope were important for connectivity and gene flow. Contrastingly, forest cover and roads favoured (broad-scale) and limited (fine-scale) connectivity, likely associated with movement facilitated by small forest patches and with thermoregulation. Altogether, these results support that S. grammicus alternates its thermoregulatory behaviour depending on the distance travelled and the habitat environmental conditions, and that it can disperse through relatively modified landscapes, mainly using agricultural zones. The information obtained is crucial to understanding the response of lizards to current anthropogenic pressures and their potential to adapt.

Strategies and Pathways for High-Quality Development in Primary-level Governance of Campus Security in Higher Education Institutions from a High-Level Security Perspective

At present, China s development is at a critical juncture where strategic opportunities coexist with risks and challenges. Against the backdrop of a risk society, the sudden and frequent occurrence of safety incidents in Chinese universities is evident, characterized by complex causes, severe harm, and far-reaching impacts. To integrate high-level safety throughout all fields and processes of campus safety work, and to strengthen the foundation for campus environmental stability on a broader scale, at a higher starting point, and at a higher level, the governance philosophy should first shift to multi-dimensional co-governance, proactively enhancing systemic resilience, and precise feedback loop governance. Secondly, the framework construction should focus on content expansion, the cultivation of stakeholders, and mechanism construction. Finally, through key strategies and optimization paths, promote high-quality development of Primary-level governance in university campus safety and maintain a safe and stable campus environment.

Individual canopy tree species maps for the National Ecological Observatory Network.

The ecology of forest ecosystems depends on the composition of trees. Capturing fine-grained information on individual trees at broad scales provides a unique perspective on forest ecosystems, forest restoration, and responses to disturbance. Individual tree data at wide extents promises to increase the scale of forest analysis, biogeographic research, and ecosystem monitoring without losing details on individual species composition and abundance. Computer vision using deep neural networks can convert raw sensor data into predictions of individual canopy tree species through labeled data collected by field researchers. Using over 40,000 individual tree stems as training data, we create landscape-level species predictions for over 100 million individual trees across 24 sites in the National Ecological Observatory Network (NEON). Using hierarchical multi-temporal models fine-tuned for each geographic area, we produce open-source data available as 1 km2 shapefiles with individual tree species prediction, as well as crown location, crown area, and height of 81 canopy tree species. Site-specific models had an average performance of 79% accuracy covering an average of 6 species per site, ranging from 3 to 15 species per site. All predictions are openly archived and have been uploaded to Google Earth Engine to benefit the ecology community and overlay with other remote sensing assets. We outline the potential utility and limitations of these data in ecology and computer vision research, as well as strategies for improving predictions using targeted data sampling.

Sustainable AI and the third wave of AI ethics: a structural turn

AbstractWith the introduction of the concept of Sustainable AI, considerations of the environmental impact of the technology have begun to enter AI ethics discussions. This, Aimee van Wynsberghe suggests, constitutes a new “third wave of AI ethics” which yet needs to be ushered in. In this paper, we ask what is entailed by Sustainable AI that should warrant such special accentuation. Do we find simply run-of-the-mill AI ethics applied to an environmental context? Or does Sustainable AI constitute a true a “game-changer”? We engage in a discussion about what the “waves of AI ethics” ought to mean and the criteria for labelling a wave as such. We argue that the third wave of AI ethics rests on a turn towards a structural approach for uncovering ethical issues on a broader scale, often paired with an analysis of power structures that prevent the uncovering of these issues.

The Sanctuaries of Iupiter Dolichenus in the Danubian Provinces. A functional interpretation

This article delves into the structure of Iupiter Dolichenus temples, focusing on its sanctuaries in the Danubian Provinces of Dacia, Pannonia Inferior, Pannonia Superior, Raetia, and Noricum. It emphasizes the need for a nuanced understanding of the cult's role in the religious landscape, cautioning against oversimplified theoretical approaches. Eight Dolichenus cult structures had archaeologically been identified in these provinces (Mehadia, Porolissum, Brigetio, Vetus Salina, Carnuntum I, Carnuntum II, Virunum, Vetoniana), showcasing the cult's manifestation on a broader scale. The study focuses on analyzing these temples' architectural features and functionalities, highlighting both differences and similarities. The article aims to provide a detailed examination of each sanctuary, considering phases of construction, alterations, and factors contributing to variations, through the analysis of archaeological finds and architectural characteristics related to the sanctuaries, it seeks to establish patterns and understand the role of specific chambers within these sacred precincts.

Deep Winter Mixed Layer Anchored by the Meandering Antarctic Circumpolar Current: Cross-Basin Variations

Abstract A deep winter mixed layer forms north of the Antarctic Circumpolar Current (ACC) in the Indo-Pacific sectors, while the mixed layer depth (MLD) is shallow in the Atlantic. Using observations and a global atmospheric model, this study investigates the contribution of surface buoyancy flux and background stratification to interbasin MLD variations. The surface heat flux is decomposed into broad-scale and frontal-scale variations. At the broad scale, the meandering ACC path is accompanied by a zonal wavenumber-1 structure of sea surface temperature (SST) with a warmer Pacific than the Atlantic; under the prevailing westerly winds, this temperature contrast results in larger surface heat loss facilitating deeper MLD in the Indo-Pacific sectors than in the Atlantic. In the Indian sector, the intense ACC fronts strengthen surface heat loss compared to the Pacific. The surface freshwater flux pattern largely follows that of evaporation and reinforces the heat flux pattern, especially in the southeast Pacific. A diagnostic relationship is introduced to highlight the role of ACC’s sloping isopycnals in setting a weak submixed layer stratification north of ACC. This weak stratification varies in magnitude across basins. In the Atlantic and western Indian Oceans where the ACC is at a low latitude (∼45°S), solar heating, intrusions of subtropical gyres, and energetic mesoscale eddies together maintain relatively strong stratification. In the southeast Pacific, in comparison, the ACC reaches the southernmost latitude (56°S), far away from the subtropical front. This creates weaker stratification, allowing deep mixed layers to form, aided by surface buoyancy loss.

Near-Peer Coaching to Enhance Operative Learning: An Educational Innovation for Surgical Training.

To design, implement, and evaluate a near-peer coaching model to enhance operative learning in general surgery training. There is an urgent need to maximize operative learning in surgical education. Trainees find barriers to operative learning difficult to navigate and often sacrifice educational opportunities for the sake of impression management. A prospective cohort study was conducted over a 6-month period following design and implementation of a trainee-led near-peer coaching model; "SPICE" (Set goals, Plan, Imagine, Comment and feedback, Evaluate and reflect). Semistructured interviews were conducted to explore trainees' experiences of the model. Twelve trainees participated in the study. The near-peer coaching encounters provided trainees with the psychological safety to be honest about learning needs, validated insecurities, and mitigated the pressures associated with impression management that consistently shaped consultant-trainee relationships. Trainees described improved operative performance, increased self-confidence, and a greater ability to adapt to the unexpected. Trainees adapted the use of the SPICE model to conventional consultant-trainee dynamics, which facilitated learning conversations and negotiation of operative opportunities. On a broader scale, trainees noticed an improvement in the teaching culture of the unit, describing that the use of the model legitimized the importance of perioperative learning conversations and increased consultant enthusiasm for teaching. Near-peer coaching created a unique psychological safety that facilitated authentic reflection and goal setting and improved trainee confidence. The benefits of the SPICE model were translated to other contexts and facilitated entrustment in conventional consultant-trainee relationships.

Animal exploitation by the last hunter-gatherers in the Mediterranean Iberia. New data from the Mesolithic groups from Cocina cave (Valencia, Eastern Iberia)

Mesolithic groups in Mediterranean Iberia lived during a period of bioclimatic and cultural changes. Thus, their economic behaviour and the availability of plant and animal resources show some interesting variation compared to previous periods that indicate changes in mobility patterns and social connectivity networks. This paper presents information on patterns of animal exploitation of the last hunter-gatherers in this region through zooarchaeological and taphonomic analyses of faunal remains from one of the key sites of the Iberian Peninsular Mesolithic, Cocina cave. This site is located in a mountainous woodland region with a rich Late Mesolithic archaeological record. Results indicate that Iberian ibex, red deer, and rabbits were the most hunted species, but that a diversity of other taxa were also present. The comparison to other Mediterranean sites suggests that Late Mesolithic foragers had common animal exploitation patterns with an increased taxonomic diversification and a clear connection to coastal areas. We suggest these foragers practiced a logistic pattern of food procurement, combining long-term with short-term camps including hunting spots, and in some cases evidence for broad scale social interactions. We hypothesize that Cocina cave may have served as a nexus of social and subsistence activities.

The morphological and functional traits of water bodies enhance the explanatory power of directed spatial processes in predicting the variation of macrophyte communities under the conditions of river flow regulation

AbstractThe study evaluated the influence of aquatic environmental features, morphological and functional traits of water bodies and directional spatial processes on the macrophyte community of floodplain ecosystems formed as a result of water flow regulation by the construction of dams. The fluvial processes were found to be still the main factor in the formation of geomorphological and ecological characteristics of floodplain ecosystems, and also determine the spatial patterns of variability of aquatic macrophyte communities. The influence of water properties on macrophytes is significantly spatially structured, as it is modified by the morphological and functional characteristics of the water bodies. The exchange of water in the floodplain system is influenced by the functional types of water bodies, which explains their significant correlation with spatial variables. The development of macrophyte communities on a broad scale is driven by the characteristics of the aquatic environment, the morphology of the water bodies and the functional types of the water bodies. On a fine scale, the patterns are described by a pure spatial component. The impact of fine scale patterns on the variability of macrophyte communities increases with increasing community disturbance, both natural and anthropogenic.

Paleosol-induced early dolomitization with U[sbnd]Pb age constraints and its implications for fluid pathways in ancient sandstone aquifers

In hydrogeology, a key challenge involves identifying patterns within ancient formations to forecast the distribution of fluid pathways and barriers to permeability, as well as comprehending the palaeohydrological system and its changes over time. This study addresses two main research inquiries concerning fluid flow: firstly, the influence of dolomitization induced by paleosols on flow characteristics, and secondly, the implications for fluid flow pattern distribution in continental sedimentary units. The objectives are pursued through: (1) meticulous, high-resolution measurements of porosity and permeability coupled with well-log data from an outcrop and two boreholes; (2) investigation of petrographic features of diagenetic minerals and their ages using the UPb geochronology system; and (3) an integration of these methodologies to grasp rock properties and fluid flow at a broader scale. Findings suggest that early dolomitization in continental sequences significantly affects fluid flow properties across the basin. The development of paleosols triggered early dolomitization, supported by UPb geochronology evidence. Subsequent groundwater migration along hydraulic gradients, influenced by fluctuations in the local aquifer's water table, facilitated the vertical distribution of dolomitization. Dolomitization occurred in residual pores resulting from initial mineral alteration, early lithifying the sediment and preventing mechanical compaction, thus preserving porosity. During migration events, fluids moved vertically along local faults and horizontally through the dolomitized layers of the formation, which likely remained porous at the time, leading to substantial silica mineralization.