Geological Database Research Articles

A generalized formula for predicting soil compression index using multi-evolutionary algorithm

Correlation between soil compression index (Cc) and state parameters is frequently referenced in studies investigating the fundamental mechanisms underlying changes in soil compressibility. However, developing an efficient formula for Cc that adequately captures the complexity of soil compressive behavior has been challenging for conventional approaches. This study utilized contemporary symbolic regression (SR) to propose a generalized formula for Cc that can represent the nonlinear relationships with state parameters across various soil types. A geological database from southern Vietnam was utilized to establish this data-driven formula. Data exploration revealed the apparent combined effects of moisture content (w), initial void ratio (e0), and moist density (ρ) on soil compressive behavior. Statistical indicators and graphical analysis were adopted to comprehensively assess the performance of the proposed formula against empirical equations found in the literature, aiming to gain a deeper understanding of the mechanism influencing changes in soil compressibility. The evaluation results demonstrated the efficiency of the proposed formula in predicting Cc, as evidenced by low error metrics and a good balance between precision and accuracy. Moreover, the applicability and limitations of the proposed formula were examined using different regional soils with specified geologic origins. Given its reliability and adequacy, the proposed formula explicitly quantified the nonlinear combined effects of e0, ρ and w on the compressibility of undisturbed soils. However, further research accounting for clay minerals, specimen preparation, and geologic origins is needed to enhance the universal applicability of our understanding of soil compressive behavior.

Geologic Input Databases for the 2025 Puerto Rico—U.S. Virgin Islands National Seismic Hazard Model Update: Crustal Faults Component

Abstract The last National Seismic Hazard Model (NSHM) for Puerto Rico and the U.S. Virgin Islands (PRVI) was published in 2003. In advance of the 2025 PRVI NSHM update, we created three geologic input databases to summarize new onshore and offshore fault source information in the northern Caribbean region between 62°–70° W and 16°–21° N. These databases, of fault sections, fault-zone polygons, and geologic estimates of fault activity (fault-slip rate and earthquake recurrence intervals) at specific sites, document updates to fault parameters used in prior seismic hazard models in PRVI. Fault sources were reviewed from published studies since 2003, which document substantial changes to the understanding of fault location, geometry, or activity. New fault section sources were added for features that meet the criteria of (1) length ≥7 km, (2) unequivocal evidence of recurrent tectonic Quaternary activity, and (3) documentation that is publicly available in a peer-reviewed source. In addition, we revised several broad areal sources, such as the Mona and Anegada extensional zones. The 2003 model included three fault sections and two fault-zone polygons (areal sources). These databases include 35 fault sections, 6 fault-zone polygons, and 51 earthquake geology sites. To characterize fault activity rates, slip-rate bins were assigned based on landscape expression and paleoseismic trench observations for faults without published slip-rate sites. Additional fault sources were evaluated but not included in these databases due to a lack of published information about fault location, geometry, or recurrent Quaternary activity. The PRVI NSHM 2025 geologic input databases describe crustal faulting; the geometries and coupling of Puerto Rico subduction zone and Muertos Trough models are considered in a separate database. Updates to the fault sections, fault-zone polygons, and earthquake geology databases can help inform the location and recurrence rate of damaging earthquakes in the PRVI NSHM implementation.

Predictive model for shear wave velocity of gravelly soil and its application to liquefaction triggering assessment

Several studies have established empirical correlations between shear wave velocity (Vs) and standard penetration test blow count (SPT-N) for engineering use. However, these empirical correlations cannot be applied to gravel-rich soils since the measured SPT-N is often inflated in gravel. Therefore, an empirical correlation of Vs for gravel is developed in this study using the Engineering Geological Database for the Taiwan Strong Motion Instrumentation Program. The Vs predictive model considers gravel content (GC) and coefficient of uniformity (Cu) in addition to effective vertical stress, void ratio, fines content, plasticity index, and overconsolidation ratio, which have been considered previously. The proposed model indicates that Vs increases with GC and Cu. Moreover, the Vs adjusted for GC can be used with existing Vs -based liquefaction triggering relationships to rationally define the boundary between liquefaction and non-liquefaction case histories with different GCs.

Seismic performance assessment of the historical Cathedral of Santa Maria del Fiore Dome by numerical analysis

The Cathedral of Santa Maria del Fiore was constructed in 1420 and features one of the largest masonry domes constructed without the use of reinforcement. The city of Florence is situated between two zones of seismic activity, namely Mugello and Chianti, and has been affected by earthquakes in recent years. The objective of the present work is to develop a non-linear numerical analysis of the seismic behavior of the Cathedral using the finite element method, with the aim of allowing the perpetuation of historical constructions. The seismic analysis was developed with geological database comprising seven natural accelerograms, with five return times (50, 75, 101, 201, and 475 years). This analysis entailed the detailed examination of the accelerations, tensions and deformations resulting from the application of seismic events in the Cathedral’s structure and indicate the failure zones. The greatest accelerations were observed for the seismic event with a magnitude of 6.93 Mw, a return time of 475 years, and were indicative of the most fractures in the Dome region.

Global geologic expert system and database for predicting carbonate reservoirs from seismic: Application to the Upper Jurassic

Carbonate systems are influenced by a great variety of physical and biological controlling factors that operate from global to local scales. The resulting intrinsic complexity of carbonate platforms makes them difficult to predict, especially when data are limited. Predicting geologic geometries and properties based on limited sampling or uncalibrated seismic data generally relies on a priori knowledge and equivocal interpretations that are marked by geologist perception and personal experience. To overcome these uncertain interpretations of such a complex natural system, which can become critical in frontier exploration, we developed an expert system that relies on a process-based method and a standardized data set using normalized information and parameters. The main innovation relies on the realization of knowledge- and process-based synthetic carbonate stratigraphic architectures that support seismo-stratigraphic interpretations. The workflow consists of four steps: (1) bibliographic compilation of a geologic database for each case study supported by quantitative parameters (e.g., sedimentation duration and thickness) and qualitative parameters (geodynamic context, seismic architecture, and facies model); (2) statistical analyses to establish consistent geologic classes and spatiotemporal trends; (3) process-based modeling to simulate stratigraphic architectures associated with carbonate sedimentation processes in a physically constrained numerical environment and testing different geologic hypotheses; and (4) realization of a predictive palaeogeographic map representing the global distribution of carbonate stratigraphic architectures, and estimation of controlling parameters for unconstrained case studies. The expert system is based on 77 case studies of Upper Jurassic carbonate platforms, which reveal the resemblance of these carbonate systems, in response to uniform global palaeoclimatic conditions and sea level. Significant local differences in stratigraphic architectures are related to specific geodynamic contexts and subsidence trends. The thickest carbonate platforms are developed in extensive/passive geodynamic settings such as the Central Atlantic Ocean margins, while thinner platforms form in intra- and peri-cratonic settings such as those of the Arabian region.

Earthen Builder Simulation: Representing Natural Materials and Embodied Carbon With Computational Play.

Natural building materials are critical to the future of a decarbonized built environment. Involving low-carbon and readily available materials such as clay-richsoils and plant fibers in building processes employ a range of techniques, and hence, a range of environmental and visual features, from rammed earth to cob and light straw clay. However, despite their advantages, natural materials are not represented in mainstream construction, perceived mistakenly as poor in theirperformance, low-tech, and are missing representation in training for building professionals. This research develops a digital representations-study of naturalmaterial futures and their associated embodied carbon. It links, for the first time, computational play, and critical data with traditional recipes of designing with natural materials. A digital tool for sustainable engagement was developed by utilizing a geological database of locally available soil-based repositories. As an exploratory design tool, it was tested through 24 playtests for its mechanics, graphical user interface, and perception shifts among designers and researchers. The final outcome seeks to establish a digital foundation for a more comprehensive earthen materials knowledge tool and life-cycle assessment. As a final deliverable, this work aims to unveil the strength of simulative material representations in heightening the knowledge base of an overlooked, historic, and sustainable practice.

Bedrock Geologic Database of the Indiana Portions of the Princeton, Evansville, Mount Vernon, and West Frankfort 30- x 60-minute Quadrangles

Located in the eastern Illinois Basin, the Princeton 1:100,000-scale quadrangle comprises portions of Knox, Gibson, Pike, Dubois, Posey, Vanderburgh, Warrick, and Spencer Counties in Indiana as well as small portions of Edwards, Gallatin, Wabash, and White Counties in Illinois. The mapped area is situated in the rolling topography of the Wabash Lowland and dominated by Pennsylvanian-age coal-bearing strata. Pennsylvanian siliciclastics in the Princeton quadrangle host economically important coal seams. The most widespread coal beds occur in the Carbondale Group, but the Raccoon Creek Group hosts coal of superior quality (low sulfur, low ash) in Indiana. Surface and underground mining of these coals have been extensive, with expansive impacts on the landscape and subsequent reclamation. Bedrock outcrops are obscured mainly by glacial sediments and extensive fluvial deposits from the Wabash River that formed deep channels (paleo and active) filled with outwash and alluvium. The geologic map of Gray and others (1970), the Compendium of Paleozoic Rock-Unit Stratigraphy in Indiana (1986), and Indiana Geologic Names Information System (IGNIS, https://legacy.igws.indiana.edu/ignis/) are the fundamental compilation of previous geological knowledge from this area. Additional data come from previous 1:24,000-scale mapping through the National Cooperative Mapping Program STATEMAP component. However, most information for the Bedrock Geologic Database of the Indiana Portions of the Princeton, Evansville, Mount Vernon, and West Frankfort 30- x 60-minute Quadrangles and, more broadly, the western corridor, is derived from Indiana-scale coal seam mapping conducted between 2011 and 2017 based on the National Coal Resources Data System (NCRDS), Indiana Coal Quality Database (ICQD), and geophysical logs from oil and gas wells archived in the Petroleum Database Management System (PDMS). The majority of these data were previously presented in Esri-based Indiana Coal Atlas StoryMaps for the entire western corridor. This geologic mapping project was funded in part through the STATEMAP Program supported by the U.S. Geological Survey under Cooperative Agreement No. G22AC00424. The Bedrock Geologic Database of the Indiana Portions of the Princeton, Evansville, Mount Vernon, and West Frankfort 30- x 60-minute Quadrangles is a composite geodata set that conforms to "GeMS (Geologic Map Schema)--a standard format for the digital publication of geologic maps," available at http://ngmdb.usgs.gov/Info/standards/GeMS/. Metadata records associated with each element within the geodata set contain more detailed descriptions of their purposes, constituent entities, and attributes. An OPEN shapefile version of the data set is also available. It consists of shapefiles, DBF files, and delimited text files and retains all information in the native geodatabase, but some programming will likely be necessary to assemble these components into usable formats.

Rock Art of the Ana Zaga Cave Shelter in the Archaeological Landscape of Gobustan, Azerbaijan

The Agisoft and 3D Studio Max software was used to study the petroglyphs of the Ana Zaga rock shelter, the largest in Gobustan. Stylistic features typical of various periods are described, and radiocarbon estimates for various cultural layers are given. Chronological stages in the evolution of rock art are defined. On the basis of geological data concerning transgressions and regressions of the Caspian Sea, the date of the first human settlement of the Ana Zaga shelter is estimated. The species composition of extinct faunas represented in rock art is assessed. It is concluded that in the Neolithic and Chalcolithic, following the rise of the sea level, the rock shelter became the principal habitat. In the Bronze Age, after the sea level had fallen, the middle and lower terraces became suitable for living. As new landscapes were settled, the themes of petroglyphs changed.

Geological and technological viewpoint on 3D Deposit Model – examples of use in Pniówek Coal Mine

During the more than 3 years of the “Quality” program at JSW S.A., a geological database has been built from scratch, collecting data from all exploratory boreholes, roadway profiling and the results of chemical analyses in one place – placing particular emphasis on parameters affecting the quality of coke. Working with digital databases requires new competencies for geologists – the ability to efficiently obtain information ready for further processing. As intended, the geological model became the basis for forecasting the quantity and quality of mined coal used in coke production. In the course of the work, a discrepancy became apparent between the geological interpretation of the structure of the deposit – as understood by the assumptions of the geological documentation, and the technological conditions of mining. The article presents resulting changes in the approach to modeling lithology and quality parameters. In addition, examples of the application of the geological database and the geological model in the daily work of the geological department are presented.

Geometry and tectonic history of the Northeastern Cévennes Fault System (Southeast Basin, France) : new insights from deep seismic reflection profiles

Following the Mw4.9 Le Teil surface rupture earthquake that occurred on the north-eastern Cévennes fault system (NCFS) in France, several investigations were carried out to understand the origin of the earthquake rupture. A few studies performed local modeling of the NCFS structures in three dimensions integrating the rheology of the sedimentary layers within the hypocenter zone. However, the geometry of the NCFS at the scale of the Southeast French Basin is poorly constrained and it remains difficult to locate its trace beneath the Quaternary sediments of the Rhône river valley. To address this issue, Électricité de France (EDF) carried out a deep reflection seismic survey along the NCFS. This new set of seismic profiles was interpreted using a geological data base including surface data, well data, and previous seismic data that were reprocessed. The resulting 3D structural model allows us to reconstruct a polyphase geological history during the past 320 Ma, which we divide into three major tectonic phases. We show that all structures in the basin in the study area were initiated as normal faults during the Lower Jurassic and the Lower Cretaceous. During the Upper Cretaceous, these structures were reactivated, acting as a major transfer fault zone during the Pyrenean shortening phase, then as normal faults during the Oligocene extension. The morphology and faults at the top-Carboniferous basin initiated during the Lower Jurassic strongly shaped the final structure of the NCFS during the subsequent tectonic phases. Our new results allow updating the historical geology of the Vivaro-Cévenol region and our knowledge about the structures that have affected the Southeast Basin since the Mesozoic. In the context of the Le Teil earthquake, our new structural model provides important constraints for continuing paleoseismological works that will better assess the seismic hazard in this region.

Developing a Base Domain Ontology from Geoscience Report Collection to Aid in Information Retrieval towards Spatiotemporal and Topic Association

The efficient and precise retrieval of desired information from extensive geological databases is a prominent and pivotal focus within the realm of geological information services. Conventional information retrieval methods primarily rely on keyword matching approaches, which often overlook the contextual and semantic aspects of the keywords, consequently impeding the retrieval system’s ability to accurately comprehend user query requirements. To tackle this challenge, this study proposes an ontology-driven information-retrieval framework for geological data that integrates spatiotemporal and topic associations. The framework encompasses the development of a geological domain ontology, extraction of key information, establishment of a multi-feature association and retrieval framework, and validation through a comprehensive case study. By employing the proposed framework, users are empowered to actively and automatically retrieve pertinent information, simplifying the information access process, mitigating the burden of comprehending information organization and software application models, and ultimately enhancing retrieval efficiency.

Прогнозная оценка устойчивости борта карьера в тектонически напряженном массиве

The article presents an approach to determining the stability of the pit walls and benches using a set of methods. The results of numerical modeling of the stress-and-strain state are presented for the rock mass in vicinities of one of the quarries in the Khibiny Apatite Arc. Calculations were made using elastic approach to a three-dimensional finite-element model which incorporates basic geological, mining engineering and geomechanical data. The impact of gravitational and tectonic stress field is demonstrated on the stability of the pit wall and benches during its development. Potentially unstable areas have been determined in the wall and benches of the open pit design contour. The identified features of the stress-and-strain state of the rock mass in vicinities of the pit wall make it possible to increase the justification level of technical solutions for the development of surface mining operations and to design preventive measures that would ensure the stability of structural elements of the open pit.

Query optimization-oriented lateral expansion method of distributed geological borehole database

Abstract In order to reduce the resource occupancy and retrieval efficiency of geological drilling databases, this study proposes a distributed horizontal expansion method for query optimization of geological drilling databases by constructing a comprehensive geological data subtree, analyzing the characteristics of distributed databases and elements in geological databases, and quickly retrieving data resources based on element attributes. In addition, this study has designed a method to horizontally extend the database designed for drilling holes using a multi-constraint model in order to achieve extension optimization of the distributed geological drilling database. Experiments are conducted to verify the performance and applicability of the proposed method. The experiment shows that when the geological data capacity is 80 GB, the capacity level of the geological database can be extended to 41 × 105TB using the method proposed in this study. The retrieval efficiency is higher than 89% and the resource occupancy rate is lower than 12% after the horizontal expansion of the database. By using this research method, the horizontal expansion of the geological drilling database is more effective, and can effectively reduce the resource occupancy rate and retrieval efficiency of the geological drilling databases. This has value significance for geological drilling with efficiency improvement and development.

Analysis of Coalbed Methane Production Characteristics and Influencing Factors of No. 15 Coal Seam in the Shouyang Block

Based on the basic geological data and production data of coalbed methane wells in the Shouyang Block, the characteristics and influencing factors of coalbed methane well production were analyzed, and the primary controlling factors were identified by the grey correlation method. The results show that the average daily gas production of the coalbed methane wells in the study area for the single mining of No. 15 coal ranges from 0 to 604.34 m3/d, with an average of 116.82 m3/d. The overall average gas production is relatively low, with only 7 of the 42 wells having an average gas production greater than 200 m3/d. Gas production tends to increase as the gas content increases. There is a significant positive correlation between gas saturation and average gas production. Burial depth and coal seam thickness also show a positive correlation with average gas production. On the other hand, there is a negative exponential relationship between average gas production and critical desorption pressure. Permeability, as determined by well tests in the area, exhibits a negative correlation with the gas production of coalbed methane wells. The correlation between gas production and the mean three-dimensional stress is weak. As the fractal dimension D value of fractures increases, gas production decreases. A smaller difference in horizontal principal stress is more favorable for the formation of network fractures, facilitating reservoir fracturing and resulting in better reconstructive properties. Moreover, an increase in the sand–mud ratio leads to a decrease in average gas production. The correlation between fault fractal dimension and average gas production is weak. The grey correlation method was employed to determine the controlling factors of coalbed methane production in the study area, ranked from strong to weak, as follows: coal thickness > fracture fractal dimension D value > gas saturation > coal seam gas content > horizontal stress difference coefficient > permeability > critical desorption pressure > mean value of three-dimensional principal stress > coal seam burial depth > sand–mud ratio > fault fractal dimension.

Study on Mechanism and Main Influencing Factors of Rockburst under Complex Conditions of Hard and Deep Overburden

Xinzhuang Coal Mine is a typical kilometer-deep rockburst mine in the Ningzheng mining area of China Huaneng Group, which is still in the capital construction period. At present, there are a few studies on the rockburst mechanism and prevention of this mine. In order to explore the occurrence mechanism and main influencing factors of rockburst under the complex geological conditions of large buried depth, thick topsoil, and hard overburden in Xinzhuang Coal Mine, this paper, based on the analysis of the basic geological data of the mine, deeply explores the comprehensive disaster factors of Xinzhuang Coal Mine; then, uses the analytic hierarchy process to carry out quantitative analysis of each disaster factor, and finally, it obtains the impact type and occurrence mechanism of the mine. Through research, it is found that the main disaster factors of Xinzhuang Coal Mine are mining depth, coal seam thickness, coal seam thickness change, tectonic stress field, hard overburden, roadway layout, bottom coal reservation, and tunneling activities. The key to the process of the rockburst disaster in Xinzhuang Coal Mine is the superimposed effect of static and dynamic loads on the roadway surrounding the rock system. The potential rockburst type during excavation and mining is the “high static and dynamic load disturbance” type.

Bedrock Geologic Database of the Vincennes 30- x 60-Minute Quadrangle, Indiana

Located in the eastern Illinois Basin, the Vincennes 1:100,000-scale quadrangle comprises portions of Daviess, Knox, Sullivan, and Greene Counties in Indiana. It is situated in the rolling topography of the Wabash Lowland and dominated by Pennsylvanian-age coal-bearing strata. Pennsylvanian siliciclastics in the Vincennes quadrangle host economically significant coal seams. The most widespread coal beds occur in the Carbondale Group, but the Raccoon Creek Group hosts superior coal quality (low sulfur, low ash) in Indiana. Both surface and underground mining of these coals have been extensive, with expansive impacts on the landscape and subsequent reclamation. Bedrock outcrop is largely obscured by multiple cycles of glacial sediments, and extensive fluvial activity of the Wabash River has formed deep channels (paleo and active) filled with outwash and alluvium. The geological map of Gray and others (1970) is the fundamental compilation of previous geological knowledge from this area. Additional geological information for the Vincennes quadrangle comes from previous 1:24k-scale mapping through the STATEMAP program. Specifically, Fraser and others (1998) conducted bedrock mapping in the 7.5-minute Wheatland and Washington quadrangles, and Fraser and Zlotin (1997) did some mapping in the 7.5-minute Montgomery quadrangle. Conolly and others (1996) performed a coal availability study in the 7.5-minute Wheatland quadrangle. However, the most information for the 1:100k Vincennes quadrangle and, more broadly, the western corridor, comes from the Indiana-scale coal seam mapping conducted between 2011 and 2017 based on the Indiana Coal Stratigraphic Database (NCRDS) and Indiana Coal Quality Database (ICQD), and geophysical logs from petroleum wells archived in the Petroleum Database Management System (PDMS). These data were previously presented in Esri-based Indiana Coal Atlas StoryMaps for the entire western corridor (Drobniak and others, 2017a, 2017b, 2017c, 2017d). This geologic map was funded in part through the STATEMAP Program supported by the U.S. Geological Survey under Cooperative Agreement No. G21AC10646. The Bedrock Geologic Database of the Vincennes 30- x 60- Minute Quadrangle is a composite geodata set that conforms to "GeMS (Geologic Map Schema)--a standard format for the digital publication of geologic maps," available at http://ngmdb.usgs.gov/Info/standards/GeMS/. Metadata records associated with each element within the geodata set contain more detailed descriptions of their purposes, constituent entities, and attributes. An OPEN shapefile version of the data set is also available. It consists of shapefiles, DBF files, and delimited text files and retains all information in the native geodatabase, but some programming will likely be necessary to assemble these components into usable formats.

Numerical investigations and evaluation of a puga geothermal reservoir with horizontal wells using a fully coupled thermo-hydro-geomechanical model (THM) and EDAS associated with AHP

Puga geothermal reservoir in India gives promising results for the extraction of geothermal energy. On the other hand, no systematic studies were conducted to analyze the Puga geothermal reservoir's thermo-hydro-geomechanical behavior while heat extraction. Most of the researchers concentrated more on the geological and geophysical aspects of the Puga hot spring and provided basic geological data. This information is now being examined as input towards the construction of geothermal reservoirs. In this study, the THM model is enhanced by including additional dynamic fluid, rock, and fracture features, and an integrated assessment approach is anticipated to improve the heat extraction possibilities of the Puga geothermal reservoir. The variation in rock temperature in the vicinity of the production well is influenced less compared to the vicinity of the injection well. The low-temperature region is initially befalling in the vicinity of hydraulic fractures with high conductivity, flow rate, and strong heat convection further it extends to the rock matrix. Twelve injection-production scenarios were proposed for the Puga geothermal reservoir to extract heat energy with single and dual production wells and single injection well. Scenario-2 and scenario-8 are significantly showing high production temperatures when compared to other proposed scenarios. A multi-index-based evaluation system that consists of geothermal reservoir life, thermal breakthrough time, reservoir impedance, heat power, and heat recovery is employed to examine the geothermal extraction from the Puga geothermal reservoir. An integrated evaluation technique was projected for geothermal extraction which is created by coupling the analytical hierarchy process (AHP) and evaluation based on distance from average solution (EDAS) techniques. The performance of twelve injection-production scenarios of the Puga geothermal reservoir are evaluated using the integrated evaluation technique. The results show that scenario-11 and scenario-9 were found to be the top two scenarios for the extraction of heat from the Puga geothermal reservoir. The results demonstrate that the proposed integrated evaluation system and improved THM model can be used for the evaluation of geothermal reservoirs effectively.

Study on the Early Cretaceous fluvial-desert sedimentary paleogeography in the Northwest of Ordos Basin

Abstract Early Cretaceous desert sedimentary system was developed in Northwest Ordos Basin. At present, the research degree of desert sedimentary paleogeography is low. The research on paleogeographic environment of Early Cretaceous sedimentary sandstone has guiding significance for the exploration of uranium resource and underground water resource in Northwest Ordos Basin. Based on the previous basic geological data of the lower Cretaceous in the Northwest of Ordos, through field geological survey, drilling core observation, and paleocurrent measurement, the sedimentary paleogeographic environments in different periods of Early Cretaceous had been studied. The results show that the lower Cretaceous in Northwestern Ordos Basin can be divided into two sedimentary cycles, the lower sedimentary cycle composed of Luohe Formation and Huachi-Huanhe Formation, and the upper sedimentary cycle composed of Luohandong Formation and Jingchuan Formation. Alluvial, Aeolian, and desert lake depositional systems were developed. The main sedimentary facies were alluvial fan, braided river, sand dune, dry valley, and dry lake. Alluvial fan and braided river facies had mainly developed in Luohe Formation. Braided fluvial facies mainly had developed in Huachi-Huanhe Formation, and alluvial fans locally developed around it. The deposits in Luohandong Formation were mainly aeolian sandstone, and the alluvial fan facies were inherently developed at Western and Northern margins. The depositional environment of Jingchuan formation is mainly river and lake. The tectonic evolution of lower Cretaceous had controlled the development of paleogeographic environment, and sedimentary facies had controlled the development of aquifer system. The paleogeographic environment of Early Cretaceous is conducive to the reduction and enrichment of uranium and the development of metallogenic units.

Application of data-driven multi-index overlay and BWM-MOORA MCDM methods in mineral prospectivity mapping of porphyry Cu mineralization

The present study applies proposed hybrid mathematical frameworks, namely Data-driven Multi-Index Overlay Method (DMIO) and Best Worst Method-multi objective optimization by ratio analysis (BWM-MOORA) techniques, for generating robust predictive models enhancing mineral prospectivity analysis is demonstrated. These are used for (i) weighting multiple groups of evidence maps acquired from geological databases, such as remote sensing, geological, geochemical, and geophysical, and then (ii) integrating these weighted layers into robust predictive models to assess porphyry copper prospectivity. This case study of the Chahargonbad area is a district of the volcano-plutonic Urumieh–Dokhtar magmatic arc belt. Porphyry copper deposit (exploration and development) models were used for distilling geoscientific datasets that are available into a group of evidence-based layers. The BWM-MOORA method combines two separate processes in which BWM is applied to weight each criterion and sub-criteria, whereas the MOORA approach helps rank these attributes. Each layer is first converted to another space of [0,1] by the sigmoidal logistic function to perform the critical process of integrating each of the evidence layers. Then, a concentration-area fractal model was used to classify evidences into some geospatial populations. In addition, a prospectivity / mineral potential mapping (MPM) analysis is performed using the DMIO, a well-proven, and accurate data-based methodology, to verify the satisfactoriness and validation of the applied methodology. Prediction-area (P-A) and normalized density (Nd) analysis (plots) were performed as validation methods to estimate the reliability and evaluate the relative efficiency of the MPM models. Therefore, these detailed outcomes confirm the validity of the BWM-MOORA model (Nd = 3.17), which is slightly higher than the valid and proper model DMIO (Nd = 3) in determining the specific potential mineralization regions.

Spatial distribution of water reservoirs in the Sota catchment (Benin, West Africa) and implications for local development

Water is an indispensable resource for human being and the environment. This study analyses spatial distribution of water reservoirs in the Sota catchment with regards to livestock density, population density, rainfall distribution and geological structure of the Sota catchment, and assessed the state of these reservoirs. To this end, the geographic coordinates of water reservoirs were collected and the updated database of reservoirs census in Benin, was used. In addition, livestock and population census database, rainfall data from 1980 to 2016 of twelve (12) stations and geological database were processed in ArcGIS for generating respectively the spatial layers of livestock, population, rainfall and geological map of the catchment. The reservoirs' state has been appreciated by documents exploration and in situ observations. Single factor Regression analysis was conducted to understand the relation of each of the factors with the spatial distribution of the reservoirs in the Sota catchment. The results reveal that Sota catchment contains 35 small water reservoirs mostly concentrated in its central western and south western part. The reservoir density is 0.0026 km−2. Most of the reservoirs are located within areas where livestock density, population density and rainfall amount is high: 51%, 46% and 86% respectively. However, no significant relation was found between reservoirs distribution and livestock density, population density, and rainfall respectively in the catchment. The basement geological structures of the Sota catchment are associated with 71% of the reservoirs' location. The reservoirs are threatened by siltation, lack of pastoral facilities, poor maintenance and management. In fact, 100%, 86%, 74%, 71%, 40%, and 34% of reservoirs are respectively subjected to the issues of: absence of waterers, siltation, deteriorated dyke, eutrophication, inexistent management committee, and drying up in dry season. For sustainable local development purposes, more attention should be paid to basin management planning for construction of new reservoirs and to reservoirs ‘maintenance. Future research on the reservoirs’ sustainability and monitoring surveillance are recommended.