Groundwater quality is pivotal for sustainable resource management,necessitating comprehen-sive investigation to safeguard this critical resource.This study introduces a novel methodology that inte-grates stiff diagra...Groundwater quality is pivotal for sustainable resource management,necessitating comprehen-sive investigation to safeguard this critical resource.This study introduces a novel methodology that inte-grates stiff diagrams,geostatistical analysis,and geometric computation to delineate the extent of a confined aquifer within the Chahrdoly aquifer,located west of Hamadan,Iran.For the first time,this approach combines these tools to map the boundaries of a confined aquifer based on hydrochemical characteristics.Stiff diagrams were used to calculate geometric parameters from groundwater chemistry data,followed by simulation using a linear model incorporating the semivariogram parameterγ(h).The Root Mean Square Error(RMSE)of the linear model was used to differentiate confined from unconfined aquifers based on hydrochemical signatures.Validation was conducted by generating a cross-sectional hydrogeological layer from well logs,confirming the presence of aquitard layers.The results successufully delineated the confined aquifer's extent,showing strong agreement with hydrogeological log data.By integrating stiff diagrams with semivariogram analysis,this study enhances the understanding of hydrochemical processes,offering a robust framework for groundwater resource identification and management.展开更多
Doline susceptibility mapping(DSM)in karst aquifer is important in terms of estimating the vulnerability of the aquifer to pollutants,estimating the infiltration rate,and infrastructures exposed to the development of ...Doline susceptibility mapping(DSM)in karst aquifer is important in terms of estimating the vulnerability of the aquifer to pollutants,estimating the infiltration rate,and infrastructures exposed to the development of dolines.In this research,doline susceptibility map was prepared in Saldaran mountain by generalized linear model(GLM)using 14 affecting parameters extracted from satellite images,digital elevation model,and geology map.Only 8 parameters have been inputted to the model which had correlation with dolines.In this regards,306 dolines were identified by the photogrammetric Unmanned Aerial Vehicles(UAV)method in 600 hectares of Salderan lands and then,these data were divided into the training(70%)and testing(30%)data for modelling.The results of DSM modeling showed that classified probability of doline occurrences in the Saldaran mountain were as follow:16.5%of the area high to very high,72%in the class of low to very low,and 5%in the moderate class.Also,locally,in Saldaran mountain,the Pirghar aquifer has the highest potential for the doline development,followed by Bagh Rostam and Sarab aquifers.Also,the precipitation,digital elevation model,Topographic Position Index,drainage density,slope,TRASP(transformed the circular aspect to a radiation index),Snow-Covered Days and vegetation cover index are of highest importance in the DSM modeling,respectively.Accurate evaluation of the model using the Receiver Operating Characteristics(ROC)curve represents a very good accuracy(AUC=0.953)of the DSM model.展开更多
Mountain front faults form the boundary between mountains and adjacent plains.These faults can propagate toward the plains and escalate the risk of seismic hazard for near cities.The North Tehran Fault(NTF)is a mounta...Mountain front faults form the boundary between mountains and adjacent plains.These faults can propagate toward the plains and escalate the risk of seismic hazard for near cities.The North Tehran Fault(NTF)is a mountain front fault bordering the Central Alborz with Tehran and Karaj plains.Structural and morphotectonic data from interpreted aerial photographs,satellite images,airborne geomagnetic data as well as field surveying have been used for detailed segmentation and evolution of the North Tehran Fault.This resulted in identification of the fault segments as the Niknamdeh,Darband,Darakeh-Garmdarreh,and Karaj from east to west.Active kinematics of these segments includes both thrusting and left-lateral components;but the dominant component is different among the segments.The Niknamdeh segment is connected to the Mosha Fault with a hard linkage,while its connection with the Darband segment is a widespread deformation zone.The connection zone between the Darband and Darakeh-Garmdarreh segments has the highest density of minor faults along the North Tehran Fault.The boundary of the Darakeh-Garmdarreh and Karaj segments is controlled by the F-3 transverse fault that has offset the NTF for~3 km right-laterally.The NTF has inverted from normal to dextral oblique fault in Miocene.The fault kinematics has changed from dextral to sinistral in Pliocene-Quaternary.Further regional oblique convergence resulted in minor fault reactivation such as relay ramp breaching faults,propagation of several footwall branches and hangingwall bypasses geometrical change of alluvial fans,and transfer of deformation front southwardly to the Tehran and Karaj plains.The findings of this paper are also applicable to other active oblique converging mountain fronts,inverted mountain front faults and the transition of deformation from these structures to the foreland basin.展开更多
The title of the online version of the original article was revised.The title of the original article has been revised to:Hydrochemical characterization of surface waters in Northern Tehran:Integrating cluster-based t...The title of the online version of the original article was revised.The title of the original article has been revised to:Hydrochemical characterization of surface waters in Northern Tehran:Integrating cluster-based techniques with Self-Organizing Maps.展开更多
Water quality is a critical global issue,especially in urban and semi-urban regions where natural and anthropogenic factors significantly influence surface water systems.This study evaluates the hydrochemical characte...Water quality is a critical global issue,especially in urban and semi-urban regions where natural and anthropogenic factors significantly influence surface water systems.This study evaluates the hydrochemical characteristics of surface water in the North of Tehran Rivers(NTRs),an essential water resource in a rapidly urbanizing region,using advanced clustering techniques,including Hierarchical Clustering Analysis(HCA),Fuzzy CMeans(FCM),Genetic Algorithm Fuzzy C-Means(GAFCM),and Self-Organizing Map(SOM).The research aims to address the scientific challenge of understanding spatial and temporal variability in water quality,focusing on physicochemical parameters,hydrochemical facies,and contamination sources.Water samples from six rivers collected over four seasons in 2020 were analyzed and classified into distinct clusters based on their chemical composition,revealing significant seasonal and spatial differences.Results showed that FCM and GAFCM consistently categorized the NTRs into two clusters during winter and spring and three in summer and autumn.These findings were supported by HCA and SOM,which identified clusters corresponding to specific river segments and contamination levels.The primary hydrochemical processes identified were mineral dissolution and weathering,with calcite,dolomite,and aragonite significantly influencing water chemistry.Additionally,human activities,such as wastewater discharge,were shown to contribute to elevated sulfate,nitrate,and phosphate concentrations,further corroborated by microbial analyses.By integrating HCA,FCM,and GAFCM with an artificial neural network(ANN)-based clustering method(SOM),this study provides a robust framework for evaluating surface water quality.The findings,supported by Gibbs diagrams,Hounslow ion ratio,and saturation indices,highlight the dominance of rock weathering and human impacts in shaping the hydrochemical dynamics of the NTRs.These insights contribute to the scientific understanding of water quality dynamics and offer practical guidance for sustainable water resource management and environmental protection in developing urban areas.展开更多
Fluid-rock interaction plays a critical function in physical and chemical processes associated with the formation and evolution of oil and gas reservoir space.In the diagenetic stage of shallow burial,the dissolution ...Fluid-rock interaction plays a critical function in physical and chemical processes associated with the formation and evolution of oil and gas reservoir space.In the diagenetic stage of shallow burial,the dissolution of carbonate rocks by acidic fluids is conducive to the development of secondary pore space in reservoirs.In contrast,the free drift experiment based on water bath instrument can simulate the dissolution process of carbonate rocks in shallow burial environment effectively.In order to study the shallow burial dissolution mechanism of carbonate rocks in different acid solutions,14 samples of typical carbonate rocks of Sinian,Cambrian,Ordovician,Permian and Triassic ages in the Tarim and Sichuan basins,China were used.The dissolution experiments on carbonate rocks in sulfuric acid,acetic acid,hydrochloric acid,silicic acid and carbonic acid at shallow burial temperature(30℃≤T≤90℃)were carried out using a water bath instrument.The PHREEQC software was used to simulate the dissolution of carbonate minerals,in order to compare the results of constant temperature water bath experiment.The results show that acid solutions have significant dissolution effect on shallow burial carbonate rocks when T=50–60℃,which corresponds to the burial depth of 1500–2000 m in the Tarim Basin and 1110–1480 m in the Sichuan Basin.However,there were obvious differences in the dissolution and reformation of carbonate rocks in different acids.In particular,sulfuric acid solution produced by thermochemical sulfate reduction can significantly promote the dissolution of carbonate rocks,especially dolomitic limestone.Moreover,the dissolution of limestone reservoirs is stronger than that of dolomite reservoirs in shallow burial.The results will provide new insights into the study of dissolution laws and influencing factors of reservoir spaces and the evaluation and prediction of carbonate reservoirs in China.展开更多
This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on...This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on the Jebel Gustar and Kef Lahmar area,which includes 14 sub-basins,this research uses a DEM-based technique to assess Holocene activities,lineament characteristics,and stream systems.Five geomorphic indices are used to assess relative active tectonics:the stream lengthgradient index(SL),drainage basin asymmetry(AF),valley-floor width to valley height ratio(VF),drainage basin shape(BS),and mountain front sinuosity(SMF).A weighted overlay of these five indices produces the Index of Relative Active Tectonics(IRAT)map.The findings reveal significant neotectonic activity in the study area,supported by profound basement faulting.This research highlights the morpho-structural processes and neotectonics activity in the Jebel Gustar,providing a framework for investigating the evolution of this structure.Additionally,it enhances comprehension of the interactions between the alpine range's internal zones in Eastern Algeria and the Atlasic domain.This study proposes a systematic approach to evaluate the tectonic and geomorphological dynamics of the South Setif region.展开更多
Devonian in the North Qilian orogenic belt and Hexi Corridor developed terrestrial molasse of later stage of foreland basin caused by collision between the North China plate and Qaidam microplate. The foreland basin t...Devonian in the North Qilian orogenic belt and Hexi Corridor developed terrestrial molasse of later stage of foreland basin caused by collision between the North China plate and Qaidam microplate. The foreland basin triggered a intense earthquake, and formed seismites and earthquake-related soft-sediment deformation. The soft-sediment deformation structures of Devonian in the eastern North Qilian Mts. consist of seismo-cracks, sandstone dykes, syn-depositional faults, microfoids （micro-corrugated lamination）, fluidized veins, load casts, flame structures, pillow structures and brecciation. The seismo-cracks, syn-depositional faults and microfolds are cracks, faults and folds formed directly by oscillation of earthquake. The seismic dykes formed by sediment instilling into seismic cracks. Fluidized veins were made by instilling into the seismo-fissures of the fluidized sands. The load casts, flame structures and pillow structures were formed by sinking and instilling caused from oscillation of earthquake along the face between sandy and muddy beds. The brecciation resulted from the oscillation of earthquake and cracking of sedimentary layers. The seismites and soft-sediment deformations in Devonian triggered the earthquake related to tectonic activities during the orogeny and uplift of North Qilian Mts.展开更多
The great Wenchuan （汶川） earthquake induced a large quantity of landslides. They are widely distributed and caused tremendous damages. The sliding mechanism and characteristics of these earthquake-induced landslide...The great Wenchuan （汶川） earthquake induced a large quantity of landslides. They are widely distributed and caused tremendous damages. The sliding mechanism and characteristics of these earthquake-induced landslides are different from those of conventional gravity landslides. Their occurrences are apparently controlled by the powerful earthquake, and they are characterized by high potential energy sliding and ejection sliding. In this article, the earthquake-induced landslides are classified, the characteristics of the sliding and destruction of these landslides are described, and the rela- tionship between the earthquake and the landslides is analyzed. The Donghekou （东河口） landslide is used as an example to characterize fast-moving long-distance earthquake-induced ejection slippage and landslide. This research suggests that many phenomena and issues related to earthquake-induced land- slide are beyond current recognition and knowledge, and new methodologies should be adopted to consider the effect of the earthquake as the paramount factor in the development of landslides. Furthermore, the study of fast-moving long-distance earthquake-induced landslides can also shed light on the formation of old and ancient landslides.展开更多
Abstract: Based on the study of stratigraphy and fossils, the Early Permian ocean in eastern Kunlun is recognized as a kind of reef-island ocean, in which there exist many different kinds of sediment, including patch ...Abstract: Based on the study of stratigraphy and fossils, the Early Permian ocean in eastern Kunlun is recognized as a kind of reef-island ocean, in which there exist many different kinds of sediment, including patch carbonate platform, reef facies, transitional facies and deep basin sediments. It has been found that the total contents of REEs increase gradually from carbonate platform facies to deep basin facies. Meanwhile, sediments of different facies have different REE distribution patterns and different Ce anomalies. Most of the sediments of patch carbonate platform facies or reef facies are characterized by extremely negative Ce anomalies or moderately negative Ce anomalies (Ce/Ce*=0.33 to 0.55), and medium or thin-bedded limestones of transitional facies by moderately negative Ce anomalies (Ce/Ce*=0.49 to 0.60). However, sediments of deep basin facies show weak or no negative Ce anomalies (Ce/Ce*=0.69 to 1.47), among which the value of Ce/Ce* in the radiolarian chert is 1.47.展开更多
Soil erosion is a crucial geo-environmental hazard worldwide that affects water quality and agriculture,decreases reservoir storage capacity due to sedimentation,and increases the danger of flooding and landslides.Thu...Soil erosion is a crucial geo-environmental hazard worldwide that affects water quality and agriculture,decreases reservoir storage capacity due to sedimentation,and increases the danger of flooding and landslides.Thus,this study uses geospatial modeling to produce soil erosion susceptibility maps(SESM)for the Hangu region,Khyber Pakhtunkhwa(KPK),Pakistan.The Hangu region,located in the Kohat Plateau of KPK,Pakistan,is particularly susceptible to soil erosion due to its unique geomorphological and climatic characteristics.Moreover,the Hangu region is characterized by a combination of steep slopes,variable rainfall patterns,diverse land use,and distinct soil types,all of which contribute to the complexity and severity of soil erosion processes.These factors necessitate a detailed and region-specific study to develop effective soil conservation strategies.In this research,we detected and mapped 1013 soil erosion points and prepared 12 predisposing factors(elevation,aspect,slope,Normalized Differentiate Vegetation Index(NDVI),drainage network,curvature,Land Use Land Cover(LULC),rainfall,lithology,contour,soil texture,and road network)of soil erosion using GIS platform.Additionally,GIS-based statistical models like the weight of evidence(WOE)and frequency ratio(FR)were applied to produce the SESM for the study area.The SESM was reclassified into four classes,i.e.,low,medium,high,and very high zone.The results of WOE for SESM show that 16.39%,33.02%,29.27%,and 21.30%of areas are covered by low,medium,high,and very high zones,respectively.In contrast,the FR results revealed that 16.50%,24.33%,35.55%,and 23.59%of the areas are occupied by low,medium,high,and very high classes.Furthermore,the reliability of applied models was evaluated using the Area Under Curve(AUC)technique.The validation results utilizing the area under curve showed that the success rate curve(SRC)and predicted rate curve(PRC)for WOE are 82%and 86%,respectively,while SRC and PRC for FR are 85%and 96%,respectively.The validation results revealed that the FR model performance is better and more reliable than the WOE.展开更多
Continuous global positioning system （GPS） in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the character- ist...Continuous global positioning system （GPS） in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the character- istics of postseismic deformation of the 2004 earthquake based on GPS networks operated by BIG, and the others named AGNeSS, and SuGAr networks located in northern Sumatra. We use a simple analytical logarithmic and exponential function to evaluate the postseismic deforma- tion parameters of the 2004 earthquake. We find that GPS data in northern Sumatra during time periods of 2005-2012 are fit better using the logarithmic function with dog of 104.2 ± 0.1 than using the exponential function. Our result clearly indicates that other physical mechanisms of post- seismic deformation should be taken into account rather than a single physical mechanism of afterslip only.展开更多
Ahmadabad Pb-Zn ore deposit is located in the mineral area of Bahabad in Central Iran Zone. This ore deposit like other metallogenic areas in Bahabad is found in Triassic carbonate rocks. Carbonate rocks in Shotori fo...Ahmadabad Pb-Zn ore deposit is located in the mineral area of Bahabad in Central Iran Zone. This ore deposit like other metallogenic areas in Bahabad is found in Triassic carbonate rocks. Carbonate rocks in Shotori formation have the highest frequency in the regional sequence stratigraphy. This formation is composed of TRSh1, TRSh2, TRSh3 and TRSh4 units. The TRSh3 unit hosts minerals in ore deposit Ahmadabad. Microcrystalline particles are the main constituent of these rocks. The most important minerals in this ore deposit include calamine Celestine, Cerussite and Wulfenite. The comparison of normalized ore patterns and carbonate sequence indicates that they have a specified genetic relationship. Here the TRSh2 unit is more similar to minerals.展开更多
The authors make the analysis of first arrivals of the P-wave from Ina-TEWS （Indonesian tsunami early warning system） and CTBT （comprehensive nuclear-test-band treaty） stations. These are used for earthquake early...The authors make the analysis of first arrivals of the P-wave from Ina-TEWS （Indonesian tsunami early warning system） and CTBT （comprehensive nuclear-test-band treaty） stations. These are used for earthquake early warning, magnitude determination and potential earthquake hazard mitigation based on seismogram acceleration. This research is focused on the study of energy duration of high frequency, and the maximum displacement of P-waves by observing broadband seismograms. The further analysis consists of deconvolution, integration or defferentiation, recursive filtering for data restitution, and applying a Butterworth filter of second order. The Butterworth filter uses high frequency 0.075 Hz to cut the effect of drift, and band-pass frequency 2-4 Hz for use in magnitude calculation. The authors choose potentially damaging earthquakes to be greater than Mw 〉 6.0. Based on the trigger on the three seconds the first arrival P-wave, the dominant period （Td） and amplitude displacement （Pd） was calculated by using data CISI （Indonesian CI Sompet） seismological station, Garut （west Java） and tested for data CTBT, LEM bang, Bandung （LEM station）. This research resulted determination of the P-wave arrival time accurately using integrated skewness and kurtosis. Performance data from the CTBT stations is very high. Signal to noise ratio 〉1,000 after passing through the filter. Such riset conducted to find out a rapid magnitude estimations from predominant frequency of displacement are： log Td = 0.2406 M- 1.3665 （R = 0.73） or M = 4.156 log Td ＋ 5.6797. Relationship of Pd, magnitude moment, Mw and hypocentre, R are log Pd = -4.684 ＋ 0.815 Mw - 1.36 log R. For relation of PGA （peak ground acceleration） and amplitude displacement are log PGA = 1.117 log Pd ＋ 0.728 （R = 0.91）. Furthermore, this formula can be used to support earthquake early warning in west of Java.展开更多
The Torbat-e-Heydariyeh andesitic rocks(THA)are part of the Cenozoic continental arc magmatic system of the northern branch of the Neotethys Ocean(NE Iran).Columnar jointing is the most significant feature of these ro...The Torbat-e-Heydariyeh andesitic rocks(THA)are part of the Cenozoic continental arc magmatic system of the northern branch of the Neotethys Ocean(NE Iran).Columnar jointing is the most significant feature of these rocks and they also show porphyritic,vitrophyric,and vitroglomeroporphyric textures.Plagioclase,clinopyroxene,±orthopyroxene are the major mineral phases.The SHRIMP U-Pb zircon dating yielded an age of 41.00±0.69 Ma for the rocks(Middle Eocene,Bartonian).Geochemically,they are of medium-to high-K calc-alkaline affinity.Primitive mantle-normalized diagrams exhibit enrichment in large ion lithophile elements(LILE),such as Cs and Rb,and also depleted in high field strength elements(HFSE)and heavy rare earth elements(HREE),with prominent negative anomalies of Ti,Nb,Y,and Yb,suggesting a tectonic setting of an active continental margin.The chondrite-normalized REE diagram displays enrichment of light rare earth elements(LREE;La_(N)/Yb_(N)=5.37-6.66)and small negative Eu anomalies(Eu/Eu^(*)of 0.69-0.78).Thorium enrichment implies the reaction between the mantle wedge and the melt of subducting oceanic slab,and/or subducting sediment.The role of subducted sediments along with subducted oceanic lithosphere is evident in these magmatic rocks using Ba/La versus Th/Nd and Ba/Th versus La_(N)/Sm_(N)diagrams.Theε_(Nd)(t)and(^(87)Sr/^(86)Sr)_(i)values vary between-0.1 to+0.2 and 0.70489 to 0.70501,respectively,and are compatible with parental melts from subduction of the lithospheric mantle.We suggest that the THA rocks were produced by the partial melting of the metasomatized lithospheric mantle,which corresponds to slab break-off of the northward subducted Neotethys oceanic slab in an extensional setting.The hot asthenospheric mantle upwelling triggered by the Neotethys slab break-off would severely heat the physically mixed mantle wedge peridotite and therefore caused partial melting to produce the Middle Eocene volcanic rocks in NE Iran.展开更多
Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often cau...Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often causing significant groundwater inflow during drilling due to the limitations of empirical and analytical methods. This study aims to identify the geological factors influencing water flow into the tunnel. High-flow zones' geological features have been identified and examined for this purpose. According to the geological complexity of the Nowsud tunnel, presence of different formations with different permeability and karstification have led to a high volume of underground inflow water (up to 4700 L/s) to the tunnel. The Nowsud tunnel faces significant geological and hydrogeological challenges due to its passage through the Ilam formation's LI2 unit, characterized by dissolution channels, faults, and fractures. The highest inflow rate (4700 L/s) occurred in the Hz-9 zone within the Zimkan anticline. The relationship between geological features and groundwater inflow indicates that anticlines are more susceptible to inflow than synclines. Additionally, different types of faults exhibit varying hydraulic effects, with strike-slip faults having the most significant impact on groundwater inflow, thrust faults conducting less water into the tunnel, and inflow through normal faults being negligible compared to the other two types of faults. The novelty of this paper lies in its detailed analysis of geological features influencing groundwater inflow into the Nowsud tunnel, providing empirical data on high-flow zones and differentiating the hydraulic effects of various fault types, which enhances the understanding and prediction of groundwater inflow in underground constructions.展开更多
Hiking trails are a basic type of tourist infrastructure,which,on the one hand,make areas available for tourist traffic,and on the other hand,can contribute to the protection of the natural environment(if they are wel...Hiking trails are a basic type of tourist infrastructure,which,on the one hand,make areas available for tourist traffic,and on the other hand,can contribute to the protection of the natural environment(if they are well designed and maintained).Owing to the variety of performed functions,their designation is determined by several factors:natural,technical,economic,social.Networks of trails change constantly.The aim of this article is to determine exactly what factors influence transformations within the hiking trail networks and what is their significance.To this end,three study areas in the Sudetes were analysed:one on the Polish side of the Sudetes-the Table(Stołowe)Mountains,and two on the Czech side-the rock town near the village of Sloup vČechách and the central part of Zlatohorskávrchovina.An analysis of changes in the shape of the networks over time was carried out,as well as surveys of institutions that were responsible for or influenced these transformations.These areas are characterised by a significant level of changes in the trail network.Among the factors influencing these changes,the tourist attractiveness of the area,the resilience of the environment,the intensity of tourism traffic,the environmental transformations associated with it,the history of tourism development and land ownership changes should be considered the most important.At each stage of forming networks,the key factor should be tourists’needs,including the desire to escape the urbanised environment.For this reason,trails should avoid roads with artificial(hard)surfaces and heavy automobile traffic.展开更多
The Global Navigation Satellite System (GNSS) is widely utilized for accurate positioning.One commonly applied method to obtain precise coordinate estimates is by implementing the relative positioning in network mode....The Global Navigation Satellite System (GNSS) is widely utilized for accurate positioning.One commonly applied method to obtain precise coordinate estimates is by implementing the relative positioning in network mode.However,this approach can be complex and challenging.Fortunately,The Japan Aerospace Exploration Agency (JAXA) offers freely available satellite orbit and clock correction products called Multi-GNSS Advanced Demonstration Tool for Orbit and Clock Analysis (MADOCA),which can enhance positioning accuracy through the precise point positioning (PPP) method.This study focuses on evaluating PPP static mode positioning using MADOCA products and comparing the results with the highly precise relative positioning method.By analyzing a network of 20 GNSS stations in Indonesia,we found that the PPP method using MADOCA products provided favorable positioning estimates.The median discrepancies and the corresponding median absolute deviation (MAD) for easting,northing,and up components were estimated as 9±18 mm,10±9 mm,and 3±40 mm,respectively.These results indicate that PPP with MADOCA products can be a reliable alternative for establishing Indonesia's horizontal control networks,particularly for orders 0,1,2,and 3,and for a broad spectrum of geoscience monitoring activities.However,considerations such as epoch transformations and seismic activities should be taken into account for accurate positioning applications that comply with the definition of the national reference framework.展开更多
The Piranshahr pull-apart basin,situated in the northwestern part of the Zagros Main Recent Fault(MRF),is characterized by two right-stepping segments of the dextral MRF.Here,a combination of finite element modeling t...The Piranshahr pull-apart basin,situated in the northwestern part of the Zagros Main Recent Fault(MRF),is characterized by two right-stepping segments of the dextral MRF.Here,a combination of finite element modeling techniques,especially twodimensional numerical modeling using ABAQUS software,along with field-based structural geological methods are used to assess the geometry and evolution of the pull-apart along the releasing stepovers in this strike-slip system.The utilized numerical approach applies two-dimensional(2D)finite-element modeling related to elastic Newtonian rheology to evaluate the distribution of stress and localization of strain within the pull-apart basin.This study provides valuable insights into the factors controlling the shape,as well as exploring the interaction between the pre-existing structures in this right-lateral strike-slip releasing stepover,pull-apart basin development in strike-slip systems,and stress-strain behavior by studying the impact of boundary conditions and fault overlap on the deformation pattern.The models consider three representative geometries of fault segment interactions,including underlapping,neutral,and overlapping stepovers,positioned at angles of 30°,45°,and 60°.The results indicate that increased overlap creates an extensive and elongated deformation pattern,while decrease overlap leads to block rotation and a narrow deformation pattern.In addition,the degree of overlapping between parallel strike-slip faults influences the stress and strain.The mean normal stress within the transtensional basin,located between the fault segments,exhibits an extensional nature,while the region outside the stepover experiences general compressive mean normal stresses.The Piranshahr transtensional pull-apart basin exemplifies the progressive evolution of underlapping stepovers,resulting in displaying an elongated rhomboidal to trapezoidal-shaped geometry over time.展开更多
Identifying volcanic reservoir types and their distribution patterns in volcanic edifices is important for accurate prediction and exploration of hydrocarbon reservoirs.Herein,we analyzed the distribution patterns of ...Identifying volcanic reservoir types and their distribution patterns in volcanic edifices is important for accurate prediction and exploration of hydrocarbon reservoirs.Herein,we analyzed the distribution patterns of different reservoir levels in volcanic edifices,discussed controlling factors,and reclassified reservoir types.This was done using core observations,whole-rock geochemistry,and reservoir physical property analysis,combined with logging,drilling,seismic,and oil-gas test data.Reservoirs can be divided into three classes based on their physical properties.The Mesozoic intermediate and basic rocks formed ClassⅠreservoirs,most lithologies formed ClassⅡreservoirs,and diabase intrusions and tight volcanic rocks formed ClassⅢreservoirs.Reservoirs form in different lithologies in the Huanghua depression due to weathering.Tectonic faults deepen the influence of weathering leading to the formation of reservoirs in tight.Additionally,volcanic rhythms and fractures control the vertical distribution of Cenozoic basaltic reservoirs.Volcanic reservoirs are classified into five types based on the main controlling factors and distribution patterns in volcanic edifices:tectonic-alteration,vesiclefracture,weathered-effusive,weathered-eruptive,and weathered-tectonic types.Among these,the weathered-eruptive type can easily form ClassⅠreservoirs,making it the best target for exploration.Whereas the weathered-tectonic and vesicle-fracture types tend to develop ClassⅡreservoirs and can be potential targets.The new classification takes into account the relationship between reservoir levels and their distribution in volcanic edifices,it is more conducive to igneous reservoir prediction in the Huanghua depression.This study provides a novel idea for the classification and comparative study of igneous reservoirs in petroliferous basins.展开更多
文摘Groundwater quality is pivotal for sustainable resource management,necessitating comprehen-sive investigation to safeguard this critical resource.This study introduces a novel methodology that inte-grates stiff diagrams,geostatistical analysis,and geometric computation to delineate the extent of a confined aquifer within the Chahrdoly aquifer,located west of Hamadan,Iran.For the first time,this approach combines these tools to map the boundaries of a confined aquifer based on hydrochemical characteristics.Stiff diagrams were used to calculate geometric parameters from groundwater chemistry data,followed by simulation using a linear model incorporating the semivariogram parameterγ(h).The Root Mean Square Error(RMSE)of the linear model was used to differentiate confined from unconfined aquifers based on hydrochemical signatures.Validation was conducted by generating a cross-sectional hydrogeological layer from well logs,confirming the presence of aquitard layers.The results successufully delineated the confined aquifer's extent,showing strong agreement with hydrogeological log data.By integrating stiff diagrams with semivariogram analysis,this study enhances the understanding of hydrochemical processes,offering a robust framework for groundwater resource identification and management.
文摘Doline susceptibility mapping(DSM)in karst aquifer is important in terms of estimating the vulnerability of the aquifer to pollutants,estimating the infiltration rate,and infrastructures exposed to the development of dolines.In this research,doline susceptibility map was prepared in Saldaran mountain by generalized linear model(GLM)using 14 affecting parameters extracted from satellite images,digital elevation model,and geology map.Only 8 parameters have been inputted to the model which had correlation with dolines.In this regards,306 dolines were identified by the photogrammetric Unmanned Aerial Vehicles(UAV)method in 600 hectares of Salderan lands and then,these data were divided into the training(70%)and testing(30%)data for modelling.The results of DSM modeling showed that classified probability of doline occurrences in the Saldaran mountain were as follow:16.5%of the area high to very high,72%in the class of low to very low,and 5%in the moderate class.Also,locally,in Saldaran mountain,the Pirghar aquifer has the highest potential for the doline development,followed by Bagh Rostam and Sarab aquifers.Also,the precipitation,digital elevation model,Topographic Position Index,drainage density,slope,TRASP(transformed the circular aspect to a radiation index),Snow-Covered Days and vegetation cover index are of highest importance in the DSM modeling,respectively.Accurate evaluation of the model using the Receiver Operating Characteristics(ROC)curve represents a very good accuracy(AUC=0.953)of the DSM model.
文摘Mountain front faults form the boundary between mountains and adjacent plains.These faults can propagate toward the plains and escalate the risk of seismic hazard for near cities.The North Tehran Fault(NTF)is a mountain front fault bordering the Central Alborz with Tehran and Karaj plains.Structural and morphotectonic data from interpreted aerial photographs,satellite images,airborne geomagnetic data as well as field surveying have been used for detailed segmentation and evolution of the North Tehran Fault.This resulted in identification of the fault segments as the Niknamdeh,Darband,Darakeh-Garmdarreh,and Karaj from east to west.Active kinematics of these segments includes both thrusting and left-lateral components;but the dominant component is different among the segments.The Niknamdeh segment is connected to the Mosha Fault with a hard linkage,while its connection with the Darband segment is a widespread deformation zone.The connection zone between the Darband and Darakeh-Garmdarreh segments has the highest density of minor faults along the North Tehran Fault.The boundary of the Darakeh-Garmdarreh and Karaj segments is controlled by the F-3 transverse fault that has offset the NTF for~3 km right-laterally.The NTF has inverted from normal to dextral oblique fault in Miocene.The fault kinematics has changed from dextral to sinistral in Pliocene-Quaternary.Further regional oblique convergence resulted in minor fault reactivation such as relay ramp breaching faults,propagation of several footwall branches and hangingwall bypasses geometrical change of alluvial fans,and transfer of deformation front southwardly to the Tehran and Karaj plains.The findings of this paper are also applicable to other active oblique converging mountain fronts,inverted mountain front faults and the transition of deformation from these structures to the foreland basin.
文摘The title of the online version of the original article was revised.The title of the original article has been revised to:Hydrochemical characterization of surface waters in Northern Tehran:Integrating cluster-based techniques with Self-Organizing Maps.
文摘Water quality is a critical global issue,especially in urban and semi-urban regions where natural and anthropogenic factors significantly influence surface water systems.This study evaluates the hydrochemical characteristics of surface water in the North of Tehran Rivers(NTRs),an essential water resource in a rapidly urbanizing region,using advanced clustering techniques,including Hierarchical Clustering Analysis(HCA),Fuzzy CMeans(FCM),Genetic Algorithm Fuzzy C-Means(GAFCM),and Self-Organizing Map(SOM).The research aims to address the scientific challenge of understanding spatial and temporal variability in water quality,focusing on physicochemical parameters,hydrochemical facies,and contamination sources.Water samples from six rivers collected over four seasons in 2020 were analyzed and classified into distinct clusters based on their chemical composition,revealing significant seasonal and spatial differences.Results showed that FCM and GAFCM consistently categorized the NTRs into two clusters during winter and spring and three in summer and autumn.These findings were supported by HCA and SOM,which identified clusters corresponding to specific river segments and contamination levels.The primary hydrochemical processes identified were mineral dissolution and weathering,with calcite,dolomite,and aragonite significantly influencing water chemistry.Additionally,human activities,such as wastewater discharge,were shown to contribute to elevated sulfate,nitrate,and phosphate concentrations,further corroborated by microbial analyses.By integrating HCA,FCM,and GAFCM with an artificial neural network(ANN)-based clustering method(SOM),this study provides a robust framework for evaluating surface water quality.The findings,supported by Gibbs diagrams,Hounslow ion ratio,and saturation indices,highlight the dominance of rock weathering and human impacts in shaping the hydrochemical dynamics of the NTRs.These insights contribute to the scientific understanding of water quality dynamics and offer practical guidance for sustainable water resource management and environmental protection in developing urban areas.
基金jointly supported by the Science and Technology Development Project of PetroChina Hangzhou Institute of Petroleum Geology(No.RIPED-2020-JS-51008)the Naturacl Science Foundation of China(Nos.41872250,41802159)。
文摘Fluid-rock interaction plays a critical function in physical and chemical processes associated with the formation and evolution of oil and gas reservoir space.In the diagenetic stage of shallow burial,the dissolution of carbonate rocks by acidic fluids is conducive to the development of secondary pore space in reservoirs.In contrast,the free drift experiment based on water bath instrument can simulate the dissolution process of carbonate rocks in shallow burial environment effectively.In order to study the shallow burial dissolution mechanism of carbonate rocks in different acid solutions,14 samples of typical carbonate rocks of Sinian,Cambrian,Ordovician,Permian and Triassic ages in the Tarim and Sichuan basins,China were used.The dissolution experiments on carbonate rocks in sulfuric acid,acetic acid,hydrochloric acid,silicic acid and carbonic acid at shallow burial temperature(30℃≤T≤90℃)were carried out using a water bath instrument.The PHREEQC software was used to simulate the dissolution of carbonate minerals,in order to compare the results of constant temperature water bath experiment.The results show that acid solutions have significant dissolution effect on shallow burial carbonate rocks when T=50–60℃,which corresponds to the burial depth of 1500–2000 m in the Tarim Basin and 1110–1480 m in the Sichuan Basin.However,there were obvious differences in the dissolution and reformation of carbonate rocks in different acids.In particular,sulfuric acid solution produced by thermochemical sulfate reduction can significantly promote the dissolution of carbonate rocks,especially dolomitic limestone.Moreover,the dissolution of limestone reservoirs is stronger than that of dolomite reservoirs in shallow burial.The results will provide new insights into the study of dissolution laws and influencing factors of reservoir spaces and the evaluation and prediction of carbonate reservoirs in China.
文摘This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on the Jebel Gustar and Kef Lahmar area,which includes 14 sub-basins,this research uses a DEM-based technique to assess Holocene activities,lineament characteristics,and stream systems.Five geomorphic indices are used to assess relative active tectonics:the stream lengthgradient index(SL),drainage basin asymmetry(AF),valley-floor width to valley height ratio(VF),drainage basin shape(BS),and mountain front sinuosity(SMF).A weighted overlay of these five indices produces the Index of Relative Active Tectonics(IRAT)map.The findings reveal significant neotectonic activity in the study area,supported by profound basement faulting.This research highlights the morpho-structural processes and neotectonics activity in the Jebel Gustar,providing a framework for investigating the evolution of this structure.Additionally,it enhances comprehension of the interactions between the alpine range's internal zones in Eastern Algeria and the Atlasic domain.This study proposes a systematic approach to evaluate the tectonic and geomorphological dynamics of the South Setif region.
基金supported by the National Natural Science Foundation of China(NO,40672080,40621002)the Program for Innovative Research Team in University of the Ministry of Education of China(IRT00546)"111 Project"(Grant No.B08030)
文摘Devonian in the North Qilian orogenic belt and Hexi Corridor developed terrestrial molasse of later stage of foreland basin caused by collision between the North China plate and Qaidam microplate. The foreland basin triggered a intense earthquake, and formed seismites and earthquake-related soft-sediment deformation. The soft-sediment deformation structures of Devonian in the eastern North Qilian Mts. consist of seismo-cracks, sandstone dykes, syn-depositional faults, microfoids （micro-corrugated lamination）, fluidized veins, load casts, flame structures, pillow structures and brecciation. The seismo-cracks, syn-depositional faults and microfolds are cracks, faults and folds formed directly by oscillation of earthquake. The seismic dykes formed by sediment instilling into seismic cracks. Fluidized veins were made by instilling into the seismo-fissures of the fluidized sands. The load casts, flame structures and pillow structures were formed by sinking and instilling caused from oscillation of earthquake along the face between sandy and muddy beds. The brecciation resulted from the oscillation of earthquake and cracking of sedimentary layers. The seismites and soft-sediment deformations in Devonian triggered the earthquake related to tectonic activities during the orogeny and uplift of North Qilian Mts.
文摘The great Wenchuan （汶川） earthquake induced a large quantity of landslides. They are widely distributed and caused tremendous damages. The sliding mechanism and characteristics of these earthquake-induced landslides are different from those of conventional gravity landslides. Their occurrences are apparently controlled by the powerful earthquake, and they are characterized by high potential energy sliding and ejection sliding. In this article, the earthquake-induced landslides are classified, the characteristics of the sliding and destruction of these landslides are described, and the rela- tionship between the earthquake and the landslides is analyzed. The Donghekou （东河口） landslide is used as an example to characterize fast-moving long-distance earthquake-induced ejection slippage and landslide. This research suggests that many phenomena and issues related to earthquake-induced land- slide are beyond current recognition and knowledge, and new methodologies should be adopted to consider the effect of the earthquake as the paramount factor in the development of landslides. Furthermore, the study of fast-moving long-distance earthquake-induced landslides can also shed light on the formation of old and ancient landslides.
文摘Abstract: Based on the study of stratigraphy and fossils, the Early Permian ocean in eastern Kunlun is recognized as a kind of reef-island ocean, in which there exist many different kinds of sediment, including patch carbonate platform, reef facies, transitional facies and deep basin sediments. It has been found that the total contents of REEs increase gradually from carbonate platform facies to deep basin facies. Meanwhile, sediments of different facies have different REE distribution patterns and different Ce anomalies. Most of the sediments of patch carbonate platform facies or reef facies are characterized by extremely negative Ce anomalies or moderately negative Ce anomalies (Ce/Ce*=0.33 to 0.55), and medium or thin-bedded limestones of transitional facies by moderately negative Ce anomalies (Ce/Ce*=0.49 to 0.60). However, sediments of deep basin facies show weak or no negative Ce anomalies (Ce/Ce*=0.69 to 1.47), among which the value of Ce/Ce* in the radiolarian chert is 1.47.
基金The authors extend their appreciation to Researchers Supporting Project number(RSP2024R390),King Saud University,Riyadh,Saudi Arabia.
文摘Soil erosion is a crucial geo-environmental hazard worldwide that affects water quality and agriculture,decreases reservoir storage capacity due to sedimentation,and increases the danger of flooding and landslides.Thus,this study uses geospatial modeling to produce soil erosion susceptibility maps(SESM)for the Hangu region,Khyber Pakhtunkhwa(KPK),Pakistan.The Hangu region,located in the Kohat Plateau of KPK,Pakistan,is particularly susceptible to soil erosion due to its unique geomorphological and climatic characteristics.Moreover,the Hangu region is characterized by a combination of steep slopes,variable rainfall patterns,diverse land use,and distinct soil types,all of which contribute to the complexity and severity of soil erosion processes.These factors necessitate a detailed and region-specific study to develop effective soil conservation strategies.In this research,we detected and mapped 1013 soil erosion points and prepared 12 predisposing factors(elevation,aspect,slope,Normalized Differentiate Vegetation Index(NDVI),drainage network,curvature,Land Use Land Cover(LULC),rainfall,lithology,contour,soil texture,and road network)of soil erosion using GIS platform.Additionally,GIS-based statistical models like the weight of evidence(WOE)and frequency ratio(FR)were applied to produce the SESM for the study area.The SESM was reclassified into four classes,i.e.,low,medium,high,and very high zone.The results of WOE for SESM show that 16.39%,33.02%,29.27%,and 21.30%of areas are covered by low,medium,high,and very high zones,respectively.In contrast,the FR results revealed that 16.50%,24.33%,35.55%,and 23.59%of the areas are occupied by low,medium,high,and very high classes.Furthermore,the reliability of applied models was evaluated using the Area Under Curve(AUC)technique.The validation results utilizing the area under curve showed that the success rate curve(SRC)and predicted rate curve(PRC)for WOE are 82%and 86%,respectively,while SRC and PRC for FR are 85%and 96%,respectively.The validation results revealed that the FR model performance is better and more reliable than the WOE.
基金funded by the PLN APJ of Sukabumi No.203/060/APJ-SKI/2010Indonesia Endowment Fund for Education(LPDP) No.PRJ1048/LPDP/2015the Australian Department of Foreign Affairs and Trade(DFAT) for Graduate Research on Earthquake and Active Tectonics at the Bandung Institute of Technology
文摘Continuous global positioning system （GPS） in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the character- istics of postseismic deformation of the 2004 earthquake based on GPS networks operated by BIG, and the others named AGNeSS, and SuGAr networks located in northern Sumatra. We use a simple analytical logarithmic and exponential function to evaluate the postseismic deforma- tion parameters of the 2004 earthquake. We find that GPS data in northern Sumatra during time periods of 2005-2012 are fit better using the logarithmic function with dog of 104.2 ± 0.1 than using the exponential function. Our result clearly indicates that other physical mechanisms of post- seismic deformation should be taken into account rather than a single physical mechanism of afterslip only.
文摘Ahmadabad Pb-Zn ore deposit is located in the mineral area of Bahabad in Central Iran Zone. This ore deposit like other metallogenic areas in Bahabad is found in Triassic carbonate rocks. Carbonate rocks in Shotori formation have the highest frequency in the regional sequence stratigraphy. This formation is composed of TRSh1, TRSh2, TRSh3 and TRSh4 units. The TRSh3 unit hosts minerals in ore deposit Ahmadabad. Microcrystalline particles are the main constituent of these rocks. The most important minerals in this ore deposit include calamine Celestine, Cerussite and Wulfenite. The comparison of normalized ore patterns and carbonate sequence indicates that they have a specified genetic relationship. Here the TRSh2 unit is more similar to minerals.
文摘The authors make the analysis of first arrivals of the P-wave from Ina-TEWS （Indonesian tsunami early warning system） and CTBT （comprehensive nuclear-test-band treaty） stations. These are used for earthquake early warning, magnitude determination and potential earthquake hazard mitigation based on seismogram acceleration. This research is focused on the study of energy duration of high frequency, and the maximum displacement of P-waves by observing broadband seismograms. The further analysis consists of deconvolution, integration or defferentiation, recursive filtering for data restitution, and applying a Butterworth filter of second order. The Butterworth filter uses high frequency 0.075 Hz to cut the effect of drift, and band-pass frequency 2-4 Hz for use in magnitude calculation. The authors choose potentially damaging earthquakes to be greater than Mw 〉 6.0. Based on the trigger on the three seconds the first arrival P-wave, the dominant period （Td） and amplitude displacement （Pd） was calculated by using data CISI （Indonesian CI Sompet） seismological station, Garut （west Java） and tested for data CTBT, LEM bang, Bandung （LEM station）. This research resulted determination of the P-wave arrival time accurately using integrated skewness and kurtosis. Performance data from the CTBT stations is very high. Signal to noise ratio 〉1,000 after passing through the filter. Such riset conducted to find out a rapid magnitude estimations from predominant frequency of displacement are： log Td = 0.2406 M- 1.3665 （R = 0.73） or M = 4.156 log Td ＋ 5.6797. Relationship of Pd, magnitude moment, Mw and hypocentre, R are log Pd = -4.684 ＋ 0.815 Mw - 1.36 log R. For relation of PGA （peak ground acceleration） and amplitude displacement are log PGA = 1.117 log Pd ＋ 0.728 （R = 0.91）. Furthermore, this formula can be used to support earthquake early warning in west of Java.
文摘The Torbat-e-Heydariyeh andesitic rocks(THA)are part of the Cenozoic continental arc magmatic system of the northern branch of the Neotethys Ocean(NE Iran).Columnar jointing is the most significant feature of these rocks and they also show porphyritic,vitrophyric,and vitroglomeroporphyric textures.Plagioclase,clinopyroxene,±orthopyroxene are the major mineral phases.The SHRIMP U-Pb zircon dating yielded an age of 41.00±0.69 Ma for the rocks(Middle Eocene,Bartonian).Geochemically,they are of medium-to high-K calc-alkaline affinity.Primitive mantle-normalized diagrams exhibit enrichment in large ion lithophile elements(LILE),such as Cs and Rb,and also depleted in high field strength elements(HFSE)and heavy rare earth elements(HREE),with prominent negative anomalies of Ti,Nb,Y,and Yb,suggesting a tectonic setting of an active continental margin.The chondrite-normalized REE diagram displays enrichment of light rare earth elements(LREE;La_(N)/Yb_(N)=5.37-6.66)and small negative Eu anomalies(Eu/Eu^(*)of 0.69-0.78).Thorium enrichment implies the reaction between the mantle wedge and the melt of subducting oceanic slab,and/or subducting sediment.The role of subducted sediments along with subducted oceanic lithosphere is evident in these magmatic rocks using Ba/La versus Th/Nd and Ba/Th versus La_(N)/Sm_(N)diagrams.Theε_(Nd)(t)and(^(87)Sr/^(86)Sr)_(i)values vary between-0.1 to+0.2 and 0.70489 to 0.70501,respectively,and are compatible with parental melts from subduction of the lithospheric mantle.We suggest that the THA rocks were produced by the partial melting of the metasomatized lithospheric mantle,which corresponds to slab break-off of the northward subducted Neotethys oceanic slab in an extensional setting.The hot asthenospheric mantle upwelling triggered by the Neotethys slab break-off would severely heat the physically mixed mantle wedge peridotite and therefore caused partial melting to produce the Middle Eocene volcanic rocks in NE Iran.
文摘Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often causing significant groundwater inflow during drilling due to the limitations of empirical and analytical methods. This study aims to identify the geological factors influencing water flow into the tunnel. High-flow zones' geological features have been identified and examined for this purpose. According to the geological complexity of the Nowsud tunnel, presence of different formations with different permeability and karstification have led to a high volume of underground inflow water (up to 4700 L/s) to the tunnel. The Nowsud tunnel faces significant geological and hydrogeological challenges due to its passage through the Ilam formation's LI2 unit, characterized by dissolution channels, faults, and fractures. The highest inflow rate (4700 L/s) occurred in the Hz-9 zone within the Zimkan anticline. The relationship between geological features and groundwater inflow indicates that anticlines are more susceptible to inflow than synclines. Additionally, different types of faults exhibit varying hydraulic effects, with strike-slip faults having the most significant impact on groundwater inflow, thrust faults conducting less water into the tunnel, and inflow through normal faults being negligible compared to the other two types of faults. The novelty of this paper lies in its detailed analysis of geological features influencing groundwater inflow into the Nowsud tunnel, providing empirical data on high-flow zones and differentiating the hydraulic effects of various fault types, which enhances the understanding and prediction of groundwater inflow in underground constructions.
文摘Hiking trails are a basic type of tourist infrastructure,which,on the one hand,make areas available for tourist traffic,and on the other hand,can contribute to the protection of the natural environment(if they are well designed and maintained).Owing to the variety of performed functions,their designation is determined by several factors:natural,technical,economic,social.Networks of trails change constantly.The aim of this article is to determine exactly what factors influence transformations within the hiking trail networks and what is their significance.To this end,three study areas in the Sudetes were analysed:one on the Polish side of the Sudetes-the Table(Stołowe)Mountains,and two on the Czech side-the rock town near the village of Sloup vČechách and the central part of Zlatohorskávrchovina.An analysis of changes in the shape of the networks over time was carried out,as well as surveys of institutions that were responsible for or influenced these transformations.These areas are characterised by a significant level of changes in the trail network.Among the factors influencing these changes,the tourist attractiveness of the area,the resilience of the environment,the intensity of tourism traffic,the environmental transformations associated with it,the history of tourism development and land ownership changes should be considered the most important.At each stage of forming networks,the key factor should be tourists’needs,including the desire to escape the urbanised environment.For this reason,trails should avoid roads with artificial(hard)surfaces and heavy automobile traffic.
文摘The Global Navigation Satellite System (GNSS) is widely utilized for accurate positioning.One commonly applied method to obtain precise coordinate estimates is by implementing the relative positioning in network mode.However,this approach can be complex and challenging.Fortunately,The Japan Aerospace Exploration Agency (JAXA) offers freely available satellite orbit and clock correction products called Multi-GNSS Advanced Demonstration Tool for Orbit and Clock Analysis (MADOCA),which can enhance positioning accuracy through the precise point positioning (PPP) method.This study focuses on evaluating PPP static mode positioning using MADOCA products and comparing the results with the highly precise relative positioning method.By analyzing a network of 20 GNSS stations in Indonesia,we found that the PPP method using MADOCA products provided favorable positioning estimates.The median discrepancies and the corresponding median absolute deviation (MAD) for easting,northing,and up components were estimated as 9±18 mm,10±9 mm,and 3±40 mm,respectively.These results indicate that PPP with MADOCA products can be a reliable alternative for establishing Indonesia's horizontal control networks,particularly for orders 0,1,2,and 3,and for a broad spectrum of geoscience monitoring activities.However,considerations such as epoch transformations and seismic activities should be taken into account for accurate positioning applications that comply with the definition of the national reference framework.
基金the financial support provided by (Shahid Beheshti University)
文摘The Piranshahr pull-apart basin,situated in the northwestern part of the Zagros Main Recent Fault(MRF),is characterized by two right-stepping segments of the dextral MRF.Here,a combination of finite element modeling techniques,especially twodimensional numerical modeling using ABAQUS software,along with field-based structural geological methods are used to assess the geometry and evolution of the pull-apart along the releasing stepovers in this strike-slip system.The utilized numerical approach applies two-dimensional(2D)finite-element modeling related to elastic Newtonian rheology to evaluate the distribution of stress and localization of strain within the pull-apart basin.This study provides valuable insights into the factors controlling the shape,as well as exploring the interaction between the pre-existing structures in this right-lateral strike-slip releasing stepover,pull-apart basin development in strike-slip systems,and stress-strain behavior by studying the impact of boundary conditions and fault overlap on the deformation pattern.The models consider three representative geometries of fault segment interactions,including underlapping,neutral,and overlapping stepovers,positioned at angles of 30°,45°,and 60°.The results indicate that increased overlap creates an extensive and elongated deformation pattern,while decrease overlap leads to block rotation and a narrow deformation pattern.In addition,the degree of overlapping between parallel strike-slip faults influences the stress and strain.The mean normal stress within the transtensional basin,located between the fault segments,exhibits an extensional nature,while the region outside the stepover experiences general compressive mean normal stresses.The Piranshahr transtensional pull-apart basin exemplifies the progressive evolution of underlapping stepovers,resulting in displaying an elongated rhomboidal to trapezoidal-shaped geometry over time.
基金financially supported by the National Natural Science Foundation of China(No.42130309)the PetroChina Dagang Oilfield Company(No.DGTY-2018-JS-408)。
文摘Identifying volcanic reservoir types and their distribution patterns in volcanic edifices is important for accurate prediction and exploration of hydrocarbon reservoirs.Herein,we analyzed the distribution patterns of different reservoir levels in volcanic edifices,discussed controlling factors,and reclassified reservoir types.This was done using core observations,whole-rock geochemistry,and reservoir physical property analysis,combined with logging,drilling,seismic,and oil-gas test data.Reservoirs can be divided into three classes based on their physical properties.The Mesozoic intermediate and basic rocks formed ClassⅠreservoirs,most lithologies formed ClassⅡreservoirs,and diabase intrusions and tight volcanic rocks formed ClassⅢreservoirs.Reservoirs form in different lithologies in the Huanghua depression due to weathering.Tectonic faults deepen the influence of weathering leading to the formation of reservoirs in tight.Additionally,volcanic rhythms and fractures control the vertical distribution of Cenozoic basaltic reservoirs.Volcanic reservoirs are classified into five types based on the main controlling factors and distribution patterns in volcanic edifices:tectonic-alteration,vesiclefracture,weathered-effusive,weathered-eruptive,and weathered-tectonic types.Among these,the weathered-eruptive type can easily form ClassⅠreservoirs,making it the best target for exploration.Whereas the weathered-tectonic and vesicle-fracture types tend to develop ClassⅡreservoirs and can be potential targets.The new classification takes into account the relationship between reservoir levels and their distribution in volcanic edifices,it is more conducive to igneous reservoir prediction in the Huanghua depression.This study provides a novel idea for the classification and comparative study of igneous reservoirs in petroliferous basins.
