Gas hydrates are ice-like combinations of methane and water.The global inventory of gas hydrates appears to be very large.Recent estimates of the total amount of methane contained in the world’s gas hydrates range
This article presents a research study of complex limestone karst engineering-geological conditions in the municipality Valaskanear Banska Bystrica in Slovakia.The aim of the study is to demonstrate the impossibility ...This article presents a research study of complex limestone karst engineering-geological conditions in the municipality Valaskanear Banska Bystrica in Slovakia.The aim of the study is to demonstrate the impossibility of spatial identification of cave spaces using surface geophysical methods due to the specific engineering-geological conditions of a thick surface layer of anthropogenic fill containing highly heterogeneous anthropogenic material.Its maximum thickness is 3 m.Another specificific condition of the study area is its location in the built-up area,due to which the applicability of geophysical methods was limited.The article contains methodological recommendations to be used in analogous geological conditions with karst structures topped with anthropogenic fill,which complicates the identification of cave spaces.The recommended solution herein is the identification of the cave system using underground mapping of the karst and its projection onto the surface for which surface geophysical methods have been combined.展开更多
The most important aspect of every civil engineering project is acquiring reliable information on the ground on which the project will be constructed. This research includes a site investigation, which is seen as a pr...The most important aspect of every civil engineering project is acquiring reliable information on the ground on which the project will be constructed. This research includes a site investigation, which is seen as a primary stage in gathering geological, geotechnical, and other essential engineering data for structures’ safe and cost-effective design. Five boreholes at well-spaced spots were drilled for subsurface investigation at a maximum depth of 15 m to 30 m. The standard penetration tests (SPT) were performed at different depths, soil samples were taken at various intervals, and lithological changes were observed. The friction angle was between 19.6ºand 33.03º, whereas the cohesion ranges between 0.25 kg/cm<sup>2</sup> and 0.42 kg/cm<sup>2</sup>, indicating a strong resistance to shearing and a high capacity to sustain the load. Furthermore, the soil samples’ maximum dry density ranges from 1.63 g/cm<sup>3</sup> to 1.80 g/cm<sup>3</sup>. In addition, water table depths were recorded from 6.0 m to 7.0 m. The net bearing capacity for isolated/pad foundation at a depth of 1.5 m to 2.5 m below the ground level has been calculated as 95.0 to 120.0 kPa and 120.0 to 180.0 kPa for raft foundation. The net allowable pressure settlement limits for isolated/pad and raft foundations are 25 mm (1-inch) and 50 mm (2-inches), respectively. The investigation has found no severe geological flaws on the proposed construction site, and therefore it is appropriate for the construction of an Air Separation Unit (ASU) Oxygen Plant.展开更多
The objective of this paper is to demonstrate necessity to inform relevant parties about engineering-geological conditions for various practical purposes, especially including appropriate land-use planning. However, t...The objective of this paper is to demonstrate necessity to inform relevant parties about engineering-geological conditions for various practical purposes, especially including appropriate land-use planning. However, the relationship between relevant geological information and the geological environment is vital for foundation engineering purposes, especially where demanding structures are involved. This information is most conveniently structured when accumulated information concerning engineering-geological zones is utilized. This necessarily includes knowledge of rock workability and also of the pre-Quaternary bedrock, and these characteristics were then related to the current built-up area and future development according to the land-use plans in a case study are from the Petrvald Region （Czech Republic）. The geological environment of area has been severely influenced by anthropogenic effects of deep black coal mining. Results of this research showed that future development should be founded on spoil banks, dumps, and settling basins. According to the land-use plan, this zone occupies 44.9% of the area of interest, and its materials predominantly emanate from mining in the Ostrava-Karvina Coal District. For future foundation structures planned there, it is imperative to consult detailed engineering-geological study. However, attention to and reliance on this necessity is not reflected in the existing land-use plan.展开更多
In this study, the geological, petrographical properties of rhyolitic tuffs exposed around ?an-Etili in the Biga Peninsula (NW Turkey) which are pyroclastic products of Late Oligocene-Early Miocene aged ?an Volcanism ...In this study, the geological, petrographical properties of rhyolitic tuffs exposed around ?an-Etili in the Biga Peninsula (NW Turkey) which are pyroclastic products of Late Oligocene-Early Miocene aged ?an Volcanism were investigated, also physical and mechanical characteristics of tuffs introduced and tried to determine the impact on engineering properties of petrographical features. In the region, rhyolitic tuffs called locally “?an stone” have been used as covering and building stones for many years. These tuffs generally have light yellowish, beige, brown colored and different patterns with light yellowish, cream, reddish and brown colors caused by iron oxidation of hydrothermal alteration. They are preferred as coatings and decorative stone with these patterns. ?an stone which consisted of rhyolitic composition, lithic and locally crystalline tuffs has compact structure. The mineral assemblage of tuffs is mainly composed of quartz, plagioclase, rarely biotite, amphibole (hornblende) phenocrystals and opaque mineral with particles of volcanic glass and lithic fragments. Not only petrographical and geochemical analyses were carried out but also standard rock mechanic tests (unit weight, specific gravity, porosity, water absorption and uniaxial compressive strength) on rhyolitic tuffs samples collected from four different quarries (Hoppa Hill, Halilaga, Uzunalan, Dereoba). Simple regression analysis of test results obtained from four different regions and correlations were found good correlation between engineering proper- ties and the petrographical and chemical properties of rhyolitic tuffs.展开更多
Mine water pollution caused by improper discharge of industrial wastewater,waste liquid and waste residue into minedout areas is a new form of pollution occurred in China in recent years.This kind of pollution is buri...Mine water pollution caused by improper discharge of industrial wastewater,waste liquid and waste residue into minedout areas is a new form of pollution occurred in China in recent years.This kind of pollution is buried deeply,and it is difficult to control,dispose and repair.Deep contaminated mine water from abandoned mining areas may even enter the ocean,posing a great threat to marine ecosystems.In this study,using a water pollution incident occurred in a coal field at a depth of 80 m in Shandong Province,China,in 2015,as an example,the methods of engineering block disposal and groundwater remediation are reported,and the remediation effects are tested and evaluated by in-situ chemical detection and geophysical surveys.The test results showed that engineering blocking measures such as cut-off walls can obviously block the DNAPL diffusion process in mine water,but the blocking effect on organic pollutants dissolved in water was limited.It can slow down the diffusion process of organic gas.The presence of mining tunnels and mined-out areas in the contaminated zone enhances the diffusion speed of various pollutants,especially during the remediation process when pollutants rapidly spread throughout the entire contaminated area.Groundwater circulation extraction and oxidation methods have a significant degradation effect on pollutants like dichloromethane,but they may generate a large amount of secondary gaseous pollutants.These gaseous pollutants may migrate to the shallow subsurface through structures such as faults,leading to secondary subsurface contamination.When designing remediation plans,it is crucial to strike a balance between blocking and guiding in the context of both blocking and restoration projects for achieving effective remediation.展开更多
Xi＇an ground fractures are the most typical ground fractures in China. Fourteen fractures have nearly divided the historical city into several distinct sections. These fractures are parallel and dis- tributed in NEE ...Xi＇an ground fractures are the most typical ground fractures in China. Fourteen fractures have nearly divided the historical city into several distinct sections. These fractures are parallel and dis- tributed in NEE direction at the same interval, with all features exhibiting a down dropping southerly block which extends to connect with the underlying fault. The activities of fractures are primarily ex- pressed as normal faults. The faulted strata are well defined and dislocation displacement increases with depth. Thus, fractures have the characteristics of syn-sedimentary faults, which constitute the hanging wall of the Lintong-Chang＇an fault branch system. Crustal thinning caused by the uplifting of upper man- tle provides a power source for extension and stretching along the fracture surface of the upper crust, which results in a series of extensional faults and the suitable conditions for forming massive ground frac- tures. The movement of tectonic blocks influences the normal dip-slipping tension of Lintong-Chang＇an fault branches, and produces a series of secondary tectonic fractures adjacent to surface, which constitute the prototype of ground fractures. The recent regional tensile stress produced by modern mainland de- formation, also profoundly influences the current activity of Xi＇an ground fractures.展开更多
Severe gas disasters in deep mining areas are increasing,and traditional protective coal seam mining is facing significant challenges.This paper proposes an innovative technology using soft rock as the protective seam...Severe gas disasters in deep mining areas are increasing,and traditional protective coal seam mining is facing significant challenges.This paper proposes an innovative technology using soft rock as the protective seam in the absence of an appropriate coal seam.Based on the geological engineering conditions of the new horizontal first mining area of Luling Coal Mine in Huaibei,China,the impacts of different mining parameters of the soft-rock protective seam on the pressure-relief effect of the protected coal seam were analyzed through numerical simulation.The unit stress of the protected coal seam,which was less than half of the primary rock stress,was used as the mining stress pressure-relief index.The optimized interlayer space was found to be 59 m for the first soft-rock working face,with a 2 m mining thickness and 105 m face length.The physicochemical characteristics of the orebody were analyzed,and a device selection framework for the soft-rock protective seam was developed.Optimal equipment for the working face was selected,including the fully-mechanized hydraulic support and coal cutter.A production technology that combined fully-mechanized and blasting-assisted soft-rock mining was developed.Engineering practices demonstrated that normal circulation operation can be achieved on the working face of the soft-rock protective seam,with an average advancement rate of 1.64 m/d.The maximum residual gas pressure and content,which were measured at the cut hole position of the protected coal seams(Nos.8 and 9),decreased to 0.35 MPa and 4.87 m^3/t,respectively.The results suggested that soft-rock protective seam mining can produce a significant gas-control effect.展开更多
The Jiang Tso ophiolite,situated in the middle segment of the Bangong-Nujiang Suture Zone,is a part of the easternmost Qieli Lake ophiolite subzone and is close to the south of Pung Lake ophiolite.The rock association...The Jiang Tso ophiolite,situated in the middle segment of the Bangong-Nujiang Suture Zone,is a part of the easternmost Qieli Lake ophiolite subzone and is close to the south of Pung Lake ophiolite.The rock association of Jiang Tso ophiolite is relatively complete and is mainly composed of metamorphic peridotite,gabbro and diabase.Comparing with N-MORB,the ophiolite is high in Mg and low in Ti,K,Na,P,and is depleted in Nb,Ta,Hf,Th and enriched in Rb,Sr and Ba.Geochemical characteristics of the Jiang Tso ophiolite indicate it is of a supra-subduction zone type formed in the spreading ridge of back arc basin.The SHRIMP U-Pb dating of zircons from the gabbro yielded a weighted average age of 188.1±4.1 Ma(MSWD=1.4),indicating the Jiang Tso ophiolite was formed in the late stage of early Jurassic.The Sr,Nd isotopic compositions show that the Tethyan mantle domain is the depleted mantle(DM),with enriched mantle domain II(EMII).They have the same Sr,Nd isotopic composition with the India Ocean MORB type.展开更多
Cooling of the Earth＇s mantle since the Meso-Archean is predicted by thermal and petrological models to have induced a secular change in the composition of primary mantle-derived magmas-and thus bulk oceanic crust; i...Cooling of the Earth＇s mantle since the Meso-Archean is predicted by thermal and petrological models to have induced a secular change in the composition of primary mantle-derived magmas-and thus bulk oceanic crust; in particular, suggesting a decrease in maficity over time. This hypothesis underpins several recent studies that have addressed key geological questions concerning evolving plate tectonic styles, the rates and timing of continental crust formation, comparative planetology, and the emergence of complex life on Earth. Major, minor, and trace element geochemical analyses of（meta）mafic rocks preserved in the geological record allows exploration of this theory, although no consensus currently exists about the magnitude of this change and what compositions-if anything-constitute representative examples of Paleo-, Meso-, or Neo-Archean primitive oceanic crust. In this work, we review the current state of understanding of this issue, and use phase equilibria to examine the different mineral assemblages and rock types that would form during metamorphism of basalt of varying maficity in subduction zone environments. The presence（or absence） of such metamorphic products in the geological record is often used as evidence for（or against） the operation of modern-day subductiondriven plate tectonics on Earth at particular time periods; however, the control that secular changes in composition have on the stability of mineral assemblages diagnostic of subduction-zone metamorphism weakens such uniformitarianistic approaches. Geodynamic interpretations of the Archean metamorphic rock record must therefore employ a different set of petrological criteria for determining tectonothermal histories than those applied to Proterozoic or Phanerozoic equivalents.展开更多
Exploration of deep mineralization,particularly where the mineralization of interest is covered by a conductive overburden,is still a challenge for the conventional transient electromagnetic(TEM)method,which measures ...Exploration of deep mineralization,particularly where the mineralization of interest is covered by a conductive overburden,is still a challenge for the conventional transient electromagnetic(TEM)method,which measures TEM response using induction coils as the sensor.However,sensors such as fluxgate and superconductive quantum interfere device(SQUID)magnetometers can measure the B-field directly,which can provide more reliable deep information for mineralization exploration.In this paper,we report on the research and development of our newly developed high-temperature su-perconductor(HTS)SQUID magnetometer,which is cooled by liquid nitrogen at 77 K,and its applica-tion in TEM measurement for deep exploration in a gold deposit in China.This improved SQUID magnetometer version has a good performance with noise(60 fT/√Hz),slew rate(0.8 mT/S),dynamic range(100 dB),sensitivity(6.25 mV/nT),and bandwidth(DC-20 kHz).To find deep and peripheral ore in the Baiyun gold deposit located in Liaoning Province,NE China,both the SQUID magnetometer and induction coil were used for TEM data acquisition.Results show that TEM can detect the distribution of local strata and the faults contained within them.Results also indicate that the SQUID magnetome-ter has superior response performance for response over geological targets with slower decay time when compared to the induction coil signals.The SQUID magnetometer is more sensitive at observing the induced-polarization effect which is closely related to the ore-controlling faults.展开更多
Coal measure gas(also known as coal-bearing unconventional gas)is the key field and development direction of unconventional natural gas in recent years.The exploration and evaluation of coal measure gas(coalbed methan...Coal measure gas(also known as coal-bearing unconventional gas)is the key field and development direction of unconventional natural gas in recent years.The exploration and evaluation of coal measure gas(coalbed methane,coal shale gas and coal measure tight sandstone gas)from single coalbed methane has greatly expanded the field and space of resource evaluation,which is of positive significance for realizing the comprehensive utilization of coal resources,maximizing the benefits and promoting the innovation of oil and gas geological theory and technological advances in exploration and development.For the first time,in Yangmeishu Syncline of Western Guizhou Province,the public welfare coalbed methane geological survey project of China Geological Survey has been carried out a systematic geological survey of coal measure gas for the Upper Permian Longtan Formation,identified the geological conditions of coal measure gas and found high quality resources.The total geological resource quantity of coalbed methane and coal shale gas is 51.423×109 m3 and the geological resource abundance is up to 566×106 m3/km2.In this area,the coal measures are characterized by many layers of minable coal seams,large total thickness,thin to the medium thickness of the single layer,good gas-bearing property of coal seams and coal measure mudstone and sandstone,good reservoir physical property and high-pressure coefficient.According to the principle of combination of high quality and similarity of key parameters of the coal reservoir,the most favorable intervals are No.5-2,No.7 and No.13-2 coal seam in Well YMC1.And the pilot tests are carried out on coal seams and roof silty mudstone,such as staged perforation,increasing hydraulic fracturing scale and"three gas"production.The high and stable industrial gas flow with a daily gas output of more than 4000 m3 has been obtained,which has realized the breakthrough in the geological survey of coal measure gas in Southwest China.Based on the above investigation results,the geological characteristics of coal measure gas in the multi-thin-coal-seam-developed area and the coexploration and co-production methods,such as the optimization method of favorable intervals,the highefficiency fracturing and reservoir reconstruction method of coal measures,and the"three gas"drainage and production system,are systematically summarized in this paper.It will provide a reference for efficient exploration and development of coal measure gas in similar geological conditions in China.展开更多
In this study,the mechanisms of slope instabilities triggered by engineering excavations at location of a planned tunnel portal in the northwest region of Turkey were assessed,and stability of the current slopes which...In this study,the mechanisms of slope instabilities triggered by engineering excavations at location of a planned tunnel portal in the northwest region of Turkey were assessed,and stability of the current slopes which has impacts on safety of a settlement(village)and agricultural fields was investigated.In the first stage of the study,in order to identify the geological units and structural properties of the sedimentary rocks in the area,to clarify the mechanisms of instabilities and to characterize discontinuity and rock mass properties field works were conducted.In this content,geotechnical boreholes,geophysical explorations between the boreholes,line surveys to explore discontinuity properties,preparation of slope profiles using topographical techniques and sampling of rock blocks and discontinuity planes were performed.In the second stage,laboratory tests were carried out on the samples to determine the geomechnical properties of the slope forming materials and discontinuities.Then,back analyses of the instabilities were made to assess the responsible shear strength parameters of the geological units during failures by considering laboratory shear test results too.Based on the backanalyses of the failures,the strength properties of the slope debris were estimated,and it has been clarified that the residual shear strength properties are the factors controlling slip mechanism along the beddings.Following the stability analyses,it is understood that a further instability along the mass or bedding planes in the failed and redesigned area are not expected,if the current slope geometry is not changed.However,safety factor calculated for the slope in the debris is 1.1 which is well below the recommended value in the literature.The minimum safety factor for currently stable slopes which were cut at the eastern part of the failed area is 1.22 which is also less than that suggested in literature.Some remedial measures such as mini-pile or slope flattening are suggested after analyses to increase the factor of safety for this part below the settlement.展开更多
Site engineering seismic survey provides basic data for seismic effect analysis. As an important parameter of soil, shear-wave velocity is usually obtained through wave velocity testing in borehole. In this paper, the...Site engineering seismic survey provides basic data for seismic effect analysis. As an important parameter of soil, shear-wave velocity is usually obtained through wave velocity testing in borehole. In this paper, the passive source surface-wave method is introduced into the site engineering seismic survey and practically applied in an engineering site of Shijingshan District. By recording the ubiquitous weak vibration on the earth surface, extract the dispersion curve from the surface-wave components using the SPAC method and obtain the shear-wave velocity structure from inversion. Over the depth of 42 m under- ground, it totally consists of five layers with interface depth of 3.31, 4.50, 7.23, 17.41, and 42.00 m; and shear-wave velocity of 144.0, 198.3, 339.4, 744.2, and 903.7 m/s, respectively. The inversion result is used to evaluate site classification, determine the maximum shear modulus of soil, provide basis for further seismic hazard analysis and site assessment or site zoning, etc. The result shows that the passive source surface-wave method is feasible in the site engineering seismic survey and can replace boreholes,shorten survey period, and reduce engineering cost to some extent.展开更多
Ocean mining activities have been ongoing for nearly 70 years,making great contributions to industrialization.Given the increasing demand for energy,along with the restructuring of the energy supply catalyzed by effor...Ocean mining activities have been ongoing for nearly 70 years,making great contributions to industrialization.Given the increasing demand for energy,along with the restructuring of the energy supply catalyzed by efforts to achieve a low-carbon economy,deep seabed mining will play an important role in addressing energy-and resource-related problems in the future.However,deep seabed mining remains in the exploratory stage,with many challenges presented by the high-pressure,low-temperature,and complex geologic and hydrodynamic environments in deep-sea mining areas,which are inaccessible to human activities.Thus,considerable efforts are required to ensure sustainable,economic,reliable,and safe deep seabed mining.This study reviews the latest advances in marine engineering geology and the environment related to deep-sea min-ing activities,presents a bibliometric analysis of the development of ocean mineral resources since the 1950s,summarizes the development,theory,and issues related to techniques for the three stages of ocean mining(i.e.,exploration,extraction,and closure),and discusses the engineering geology environment,geological disasters,in-situ monitoring techniques,envi-ronmental protection requirements,and environmental effects in detail.Finally,this paper gives some key conclusions and future perspectives to provide insights for subsequent studies and commercial mining operations.展开更多
Suitability evaluation of urban geological environment is an important basic work in city planning and construction. With Zhengzhou-Kaifeng area as the research area, this paper discusses AHP and fuzzy comprehensive e...Suitability evaluation of urban geological environment is an important basic work in city planning and construction. With Zhengzhou-Kaifeng area as the research area, this paper discusses AHP and fuzzy comprehensive evaluation methods to classify impact factors at different levels, makes a mixing evaluation of the basic factors and comprehensive factors so as to correct the uncertainty of the weight of the basic factors in the initial evaluation and establish the corresponding evaluation index system, and carries out urban geological environment suitability evaluation in study area. Furthermore, this paper partitions the suitability of the research area according to evaluation results into five zones. It puts forward opinions and suggestions for the construction of research area, which have certain practical significances.展开更多
A multidisciplinary approach combining multiscale geological-structural analyses(from field to microscale) and clay mineral transformations(clay mineralogy, illite and chlorite "crystallinity" and b cell dim...A multidisciplinary approach combining multiscale geological-structural analyses(from field to microscale) and clay mineral transformations(clay mineralogy, illite and chlorite "crystallinity" and b cell dimension(b_(0)) of K-white mica) was adopted to unravel the tectono-metamorphic evolution of low-and very low-grade tectono-metamorphic units from the Intra-Pontide suture zone in northern Turkey. The mineralogical study allowed to better evaluate the structural stacking outlined during the geological mapping, leading to distinguish three tectono-metamorphic units, two in epizone(Daday and Emirkoy units) and one in anchizone(Cifter Unit) metamorphic conditions. The mesostructural and microstructural analyses suggest a polyphase tectonic-metamorphic evolution. The different macroscopic features observed between the two units characterized by the same epizone metamorphism, can be justified by the evidence that these metamorphic conditions were acquired during the last stages of exhumation in the Daday Unit, while they constrained the metamorphic-peak conditions in the Emirkoy Unit. Contemporary analyses and comparison between structural and mineralogical data have thus proven to be a powerful tool to investigate the low-grade and very low-grade metamorphic environments, allowing at the same time to solve the apparent contradictions deriving from the mineralogical study and to significantly improve the detail of the geological mapping in the field.展开更多
The Qinghai Lake in North China is the largest interior plateau lake in Central Asia, and is sensitive to climate change and the environmental effects of Tibetan Plateau uplift. An almost continuous 626 m long sedimen...The Qinghai Lake in North China is the largest interior plateau lake in Central Asia, and is sensitive to climate change and the environmental effects of Tibetan Plateau uplift. An almost continuous 626 m long sediment core was drilled in an in-filled part of the southern lake basin in the Scientific Drilling at Qinghai Lake.展开更多
Hydrogeological and hydrochemical assessments were carried out in Assin and Breman districts of Ghana. A multi-criteria approach was used in the assessment of the basin granitoids including;electrical resistivity surv...Hydrogeological and hydrochemical assessments were carried out in Assin and Breman districts of Ghana. A multi-criteria approach was used in the assessment of the basin granitoids including;electrical resistivity survey, pumping test and water quality analysis. A total of twenty-five (25) representative boreholes were drilled, developed and pumped;obtaining data for aquifer hydraulic parameters estimation. Correlation analysis was used to determine relationships that exist between aquifer hydraulic parameters. Schoeller, Piper, Stiff plot and Gibbs diagrams were used to determine the hydrogeochemical facies, water types and the mechanism that control groundwater quality. The statistical analysis determined that aquifer hydraulic parameters discharge rate (Q), hydraulic conductivity (K) and Transmissivity (T) showed a strong positive correlation with specific capacity (Q/Sw) with R value 0.8462, 0.8738 and 0.8332 respectively. The K and T were respectively between 0.02 - 0.90 m/day and 0.36 - 13.47 m2/day with mean of 0.24 m/day and 3.03 m2/day respectively. The K values indicate a hydrogeological condition of aquiclude with relatively low permeability and medium water bearing capacity. The aquifer T magnitude is very low to low, groundwater potential is adequate for local water supply with limited and private consumption. All physicochemical parameters were within the permissible limits of Ghana Standards Authority (GSA) and World Health Organisation (WHO) except for apparent colour, pH, Fe and Mn. Distribution of major ions in groundwater samples was calculated and the general trend among cations and anions was found to be Ca2+ > Na+ > Mg2+ and Cl? > HCO3? > SO42? respectively. The study area shows five main water types namely;Ca-HCO3, Na-Mg-HCO3-SO4, Ca-SO4, Na-Cl and Mg-Na-Cl. Weathering of rock-forming minerals as the mechanism controlling the groundwater chemistry. Microbiological parameters were above the permissible limits. Groundwater is suitable for drinking after treatment with chlorination, aeration and slow sand filtration methods.展开更多
High-intensity and large-scale resource development seriously threatens the fragile ecological environment in the red soil hilly region in southern China. This paper analyzes the eco-geological environmental problems ...High-intensity and large-scale resource development seriously threatens the fragile ecological environment in the red soil hilly region in southern China. This paper analyzes the eco-geological environmental problems and factors affecting Ganzhou, a mining city in the red soil hilly region,based on field survey and literature. The ecogeological environment quality(EGEQ) assessment system, which covered 11 indicators in physical geography, mining development, geological hazards,as well as water and soil pollution, was established through multi-source data utilization such as remote sensing images, DEM(Digital Elevation Model), field survey and on-site monitoring data. The comprehensive weight of each indicator was calculated through the Analytic Hierarchy Process(AHP) and entropy method. The eco-geological environment assessment map was developed by calculating the EGEQ value through the linear weighted method. The assessment results show that the EGEQ was classified into I-V grades from excellent to worse, among which, EGEQ of I-II accounted for 29.88%, EGEQ of III accounted for 32.35% and EGEQ of IV-V accounted for 37.77%;the overall EGEQ of Ganzhou was moderate. The assessment system utilized in this research provides scientific and accurate results, which in turn enable the proposal of some tangible protection suggestions.展开更多
基金funded by National Natural Science Foundation of China (41427803)
文摘Gas hydrates are ice-like combinations of methane and water.The global inventory of gas hydrates appears to be very large.Recent estimates of the total amount of methane contained in the world’s gas hydrates range
基金the support of the project(SP2017/22)which is the base of this articlepartially supported by the Slovak Research and Development Agency under contract No.APVV-0129-12the Scientific Grant Agency of the Ministry of Education,Science,Research and Sport of the Slovak Republic and the Slovak Academy of Sciences(VEGA)within the project No.1/0559/17 and APVV 1/0462/16。
文摘This article presents a research study of complex limestone karst engineering-geological conditions in the municipality Valaskanear Banska Bystrica in Slovakia.The aim of the study is to demonstrate the impossibility of spatial identification of cave spaces using surface geophysical methods due to the specific engineering-geological conditions of a thick surface layer of anthropogenic fill containing highly heterogeneous anthropogenic material.Its maximum thickness is 3 m.Another specificific condition of the study area is its location in the built-up area,due to which the applicability of geophysical methods was limited.The article contains methodological recommendations to be used in analogous geological conditions with karst structures topped with anthropogenic fill,which complicates the identification of cave spaces.The recommended solution herein is the identification of the cave system using underground mapping of the karst and its projection onto the surface for which surface geophysical methods have been combined.
文摘The most important aspect of every civil engineering project is acquiring reliable information on the ground on which the project will be constructed. This research includes a site investigation, which is seen as a primary stage in gathering geological, geotechnical, and other essential engineering data for structures’ safe and cost-effective design. Five boreholes at well-spaced spots were drilled for subsurface investigation at a maximum depth of 15 m to 30 m. The standard penetration tests (SPT) were performed at different depths, soil samples were taken at various intervals, and lithological changes were observed. The friction angle was between 19.6ºand 33.03º, whereas the cohesion ranges between 0.25 kg/cm<sup>2</sup> and 0.42 kg/cm<sup>2</sup>, indicating a strong resistance to shearing and a high capacity to sustain the load. Furthermore, the soil samples’ maximum dry density ranges from 1.63 g/cm<sup>3</sup> to 1.80 g/cm<sup>3</sup>. In addition, water table depths were recorded from 6.0 m to 7.0 m. The net bearing capacity for isolated/pad foundation at a depth of 1.5 m to 2.5 m below the ground level has been calculated as 95.0 to 120.0 kPa and 120.0 to 180.0 kPa for raft foundation. The net allowable pressure settlement limits for isolated/pad and raft foundations are 25 mm (1-inch) and 50 mm (2-inches), respectively. The investigation has found no severe geological flaws on the proposed construction site, and therefore it is appropriate for the construction of an Air Separation Unit (ASU) Oxygen Plant.
基金Czech Science Foundation for their support of project(GACR-105/09/1631)
文摘The objective of this paper is to demonstrate necessity to inform relevant parties about engineering-geological conditions for various practical purposes, especially including appropriate land-use planning. However, the relationship between relevant geological information and the geological environment is vital for foundation engineering purposes, especially where demanding structures are involved. This information is most conveniently structured when accumulated information concerning engineering-geological zones is utilized. This necessarily includes knowledge of rock workability and also of the pre-Quaternary bedrock, and these characteristics were then related to the current built-up area and future development according to the land-use plans in a case study are from the Petrvald Region （Czech Republic）. The geological environment of area has been severely influenced by anthropogenic effects of deep black coal mining. Results of this research showed that future development should be founded on spoil banks, dumps, and settling basins. According to the land-use plan, this zone occupies 44.9% of the area of interest, and its materials predominantly emanate from mining in the Ostrava-Karvina Coal District. For future foundation structures planned there, it is imperative to consult detailed engineering-geological study. However, attention to and reliance on this necessity is not reflected in the existing land-use plan.
基金financially supported by The Scientific and Technological Research Council of Turkey(TUBI-TAK.Project No.105Y114)
文摘In this study, the geological, petrographical properties of rhyolitic tuffs exposed around ?an-Etili in the Biga Peninsula (NW Turkey) which are pyroclastic products of Late Oligocene-Early Miocene aged ?an Volcanism were investigated, also physical and mechanical characteristics of tuffs introduced and tried to determine the impact on engineering properties of petrographical features. In the region, rhyolitic tuffs called locally “?an stone” have been used as covering and building stones for many years. These tuffs generally have light yellowish, beige, brown colored and different patterns with light yellowish, cream, reddish and brown colors caused by iron oxidation of hydrothermal alteration. They are preferred as coatings and decorative stone with these patterns. ?an stone which consisted of rhyolitic composition, lithic and locally crystalline tuffs has compact structure. The mineral assemblage of tuffs is mainly composed of quartz, plagioclase, rarely biotite, amphibole (hornblende) phenocrystals and opaque mineral with particles of volcanic glass and lithic fragments. Not only petrographical and geochemical analyses were carried out but also standard rock mechanic tests (unit weight, specific gravity, porosity, water absorption and uniaxial compressive strength) on rhyolitic tuffs samples collected from four different quarries (Hoppa Hill, Halilaga, Uzunalan, Dereoba). Simple regression analysis of test results obtained from four different regions and correlations were found good correlation between engineering proper- ties and the petrographical and chemical properties of rhyolitic tuffs.
基金supported by the Polluted Site Remediation Project of Gao Village,Puji Street,Zhangqiu District,Jinan City,Shandong Provincefinancially supported by the National Natural Science Foundation of China(Nos.42072331,U1906209)the Taishan Scholar Foundation(No.tstp20230626)。
文摘Mine water pollution caused by improper discharge of industrial wastewater,waste liquid and waste residue into minedout areas is a new form of pollution occurred in China in recent years.This kind of pollution is buried deeply,and it is difficult to control,dispose and repair.Deep contaminated mine water from abandoned mining areas may even enter the ocean,posing a great threat to marine ecosystems.In this study,using a water pollution incident occurred in a coal field at a depth of 80 m in Shandong Province,China,in 2015,as an example,the methods of engineering block disposal and groundwater remediation are reported,and the remediation effects are tested and evaluated by in-situ chemical detection and geophysical surveys.The test results showed that engineering blocking measures such as cut-off walls can obviously block the DNAPL diffusion process in mine water,but the blocking effect on organic pollutants dissolved in water was limited.It can slow down the diffusion process of organic gas.The presence of mining tunnels and mined-out areas in the contaminated zone enhances the diffusion speed of various pollutants,especially during the remediation process when pollutants rapidly spread throughout the entire contaminated area.Groundwater circulation extraction and oxidation methods have a significant degradation effect on pollutants like dichloromethane,but they may generate a large amount of secondary gaseous pollutants.These gaseous pollutants may migrate to the shallow subsurface through structures such as faults,leading to secondary subsurface contamination.When designing remediation plans,it is crucial to strike a balance between blocking and guiding in the context of both blocking and restoration projects for achieving effective remediation.
基金supported by the National Key Basic Research Project of China (No. 2014CB744703)the National Natural Science Foundation of China (Nos. 41790445, 41731066, 41674001, 41202189, 41274004, 41274005)+2 种基金the Natural Science Basic Research Plan of Shaanxi Province, China (No. 2016JM4005)the Special Fund for Basic Scientific Research of Central Universities (Nos. CHD300102268204, CHD2014G1261050, CHD2014G3263014)the China Postdoctoral Science Foundation (No. 2013M530412)
文摘Xi＇an ground fractures are the most typical ground fractures in China. Fourteen fractures have nearly divided the historical city into several distinct sections. These fractures are parallel and dis- tributed in NEE direction at the same interval, with all features exhibiting a down dropping southerly block which extends to connect with the underlying fault. The activities of fractures are primarily ex- pressed as normal faults. The faulted strata are well defined and dislocation displacement increases with depth. Thus, fractures have the characteristics of syn-sedimentary faults, which constitute the hanging wall of the Lintong-Chang＇an fault branch system. Crustal thinning caused by the uplifting of upper man- tle provides a power source for extension and stretching along the fracture surface of the upper crust, which results in a series of extensional faults and the suitable conditions for forming massive ground frac- tures. The movement of tectonic blocks influences the normal dip-slipping tension of Lintong-Chang＇an fault branches, and produces a series of secondary tectonic fractures adjacent to surface, which constitute the prototype of ground fractures. The recent regional tensile stress produced by modern mainland de- formation, also profoundly influences the current activity of Xi＇an ground fractures.
文摘Severe gas disasters in deep mining areas are increasing,and traditional protective coal seam mining is facing significant challenges.This paper proposes an innovative technology using soft rock as the protective seam in the absence of an appropriate coal seam.Based on the geological engineering conditions of the new horizontal first mining area of Luling Coal Mine in Huaibei,China,the impacts of different mining parameters of the soft-rock protective seam on the pressure-relief effect of the protected coal seam were analyzed through numerical simulation.The unit stress of the protected coal seam,which was less than half of the primary rock stress,was used as the mining stress pressure-relief index.The optimized interlayer space was found to be 59 m for the first soft-rock working face,with a 2 m mining thickness and 105 m face length.The physicochemical characteristics of the orebody were analyzed,and a device selection framework for the soft-rock protective seam was developed.Optimal equipment for the working face was selected,including the fully-mechanized hydraulic support and coal cutter.A production technology that combined fully-mechanized and blasting-assisted soft-rock mining was developed.Engineering practices demonstrated that normal circulation operation can be achieved on the working face of the soft-rock protective seam,with an average advancement rate of 1.64 m/d.The maximum residual gas pressure and content,which were measured at the cut hole position of the protected coal seams(Nos.8 and 9),decreased to 0.35 MPa and 4.87 m^3/t,respectively.The results suggested that soft-rock protective seam mining can produce a significant gas-control effect.
基金financially supported by the Tibetan special foundation of China Geological Survey(No.1212011221088 and No.1212011221087)Natural Science Foundation of China(No.41372208 and No.41472054)open foundation of State Key Laboratory of Ore Deposit Geochemistry,Chinese Academy of Sciences(No.201304)
文摘The Jiang Tso ophiolite,situated in the middle segment of the Bangong-Nujiang Suture Zone,is a part of the easternmost Qieli Lake ophiolite subzone and is close to the south of Pung Lake ophiolite.The rock association of Jiang Tso ophiolite is relatively complete and is mainly composed of metamorphic peridotite,gabbro and diabase.Comparing with N-MORB,the ophiolite is high in Mg and low in Ti,K,Na,P,and is depleted in Nb,Ta,Hf,Th and enriched in Rb,Sr and Ba.Geochemical characteristics of the Jiang Tso ophiolite indicate it is of a supra-subduction zone type formed in the spreading ridge of back arc basin.The SHRIMP U-Pb dating of zircons from the gabbro yielded a weighted average age of 188.1±4.1 Ma(MSWD=1.4),indicating the Jiang Tso ophiolite was formed in the late stage of early Jurassic.The Sr,Nd isotopic compositions show that the Tethyan mantle domain is the depleted mantle(DM),with enriched mantle domain II(EMII).They have the same Sr,Nd isotopic composition with the India Ocean MORB type.
文摘Cooling of the Earth＇s mantle since the Meso-Archean is predicted by thermal and petrological models to have induced a secular change in the composition of primary mantle-derived magmas-and thus bulk oceanic crust; in particular, suggesting a decrease in maficity over time. This hypothesis underpins several recent studies that have addressed key geological questions concerning evolving plate tectonic styles, the rates and timing of continental crust formation, comparative planetology, and the emergence of complex life on Earth. Major, minor, and trace element geochemical analyses of（meta）mafic rocks preserved in the geological record allows exploration of this theory, although no consensus currently exists about the magnitude of this change and what compositions-if anything-constitute representative examples of Paleo-, Meso-, or Neo-Archean primitive oceanic crust. In this work, we review the current state of understanding of this issue, and use phase equilibria to examine the different mineral assemblages and rock types that would form during metamorphism of basalt of varying maficity in subduction zone environments. The presence（or absence） of such metamorphic products in the geological record is often used as evidence for（or against） the operation of modern-day subductiondriven plate tectonics on Earth at particular time periods; however, the control that secular changes in composition have on the stability of mineral assemblages diagnostic of subduction-zone metamorphism weakens such uniformitarianistic approaches. Geodynamic interpretations of the Archean metamorphic rock record must therefore employ a different set of petrological criteria for determining tectonothermal histories than those applied to Proterozoic or Phanerozoic equivalents.
基金This study was supported by the National Key Research and Development Project of China(No.2018YFC0603803)Fundamental Research Funds of Chinese Academy of Geological Sciences(Nos.AS2020Y01,AS2020P01).
文摘Exploration of deep mineralization,particularly where the mineralization of interest is covered by a conductive overburden,is still a challenge for the conventional transient electromagnetic(TEM)method,which measures TEM response using induction coils as the sensor.However,sensors such as fluxgate and superconductive quantum interfere device(SQUID)magnetometers can measure the B-field directly,which can provide more reliable deep information for mineralization exploration.In this paper,we report on the research and development of our newly developed high-temperature su-perconductor(HTS)SQUID magnetometer,which is cooled by liquid nitrogen at 77 K,and its applica-tion in TEM measurement for deep exploration in a gold deposit in China.This improved SQUID magnetometer version has a good performance with noise(60 fT/√Hz),slew rate(0.8 mT/S),dynamic range(100 dB),sensitivity(6.25 mV/nT),and bandwidth(DC-20 kHz).To find deep and peripheral ore in the Baiyun gold deposit located in Liaoning Province,NE China,both the SQUID magnetometer and induction coil were used for TEM data acquisition.Results show that TEM can detect the distribution of local strata and the faults contained within them.Results also indicate that the SQUID magnetome-ter has superior response performance for response over geological targets with slower decay time when compared to the induction coil signals.The SQUID magnetometer is more sensitive at observing the induced-polarization effect which is closely related to the ore-controlling faults.
基金This study was supported by the China Geological Survey Projects(DD20160186,12120115008201)
文摘Coal measure gas(also known as coal-bearing unconventional gas)is the key field and development direction of unconventional natural gas in recent years.The exploration and evaluation of coal measure gas(coalbed methane,coal shale gas and coal measure tight sandstone gas)from single coalbed methane has greatly expanded the field and space of resource evaluation,which is of positive significance for realizing the comprehensive utilization of coal resources,maximizing the benefits and promoting the innovation of oil and gas geological theory and technological advances in exploration and development.For the first time,in Yangmeishu Syncline of Western Guizhou Province,the public welfare coalbed methane geological survey project of China Geological Survey has been carried out a systematic geological survey of coal measure gas for the Upper Permian Longtan Formation,identified the geological conditions of coal measure gas and found high quality resources.The total geological resource quantity of coalbed methane and coal shale gas is 51.423×109 m3 and the geological resource abundance is up to 566×106 m3/km2.In this area,the coal measures are characterized by many layers of minable coal seams,large total thickness,thin to the medium thickness of the single layer,good gas-bearing property of coal seams and coal measure mudstone and sandstone,good reservoir physical property and high-pressure coefficient.According to the principle of combination of high quality and similarity of key parameters of the coal reservoir,the most favorable intervals are No.5-2,No.7 and No.13-2 coal seam in Well YMC1.And the pilot tests are carried out on coal seams and roof silty mudstone,such as staged perforation,increasing hydraulic fracturing scale and"three gas"production.The high and stable industrial gas flow with a daily gas output of more than 4000 m3 has been obtained,which has realized the breakthrough in the geological survey of coal measure gas in Southwest China.Based on the above investigation results,the geological characteristics of coal measure gas in the multi-thin-coal-seam-developed area and the coexploration and co-production methods,such as the optimization method of favorable intervals,the highefficiency fracturing and reservoir reconstruction method of coal measures,and the"three gas"drainage and production system,are systematically summarized in this paper.It will provide a reference for efficient exploration and development of coal measure gas in similar geological conditions in China.
文摘In this study,the mechanisms of slope instabilities triggered by engineering excavations at location of a planned tunnel portal in the northwest region of Turkey were assessed,and stability of the current slopes which has impacts on safety of a settlement(village)and agricultural fields was investigated.In the first stage of the study,in order to identify the geological units and structural properties of the sedimentary rocks in the area,to clarify the mechanisms of instabilities and to characterize discontinuity and rock mass properties field works were conducted.In this content,geotechnical boreholes,geophysical explorations between the boreholes,line surveys to explore discontinuity properties,preparation of slope profiles using topographical techniques and sampling of rock blocks and discontinuity planes were performed.In the second stage,laboratory tests were carried out on the samples to determine the geomechnical properties of the slope forming materials and discontinuities.Then,back analyses of the instabilities were made to assess the responsible shear strength parameters of the geological units during failures by considering laboratory shear test results too.Based on the backanalyses of the failures,the strength properties of the slope debris were estimated,and it has been clarified that the residual shear strength properties are the factors controlling slip mechanism along the beddings.Following the stability analyses,it is understood that a further instability along the mass or bedding planes in the failed and redesigned area are not expected,if the current slope geometry is not changed.However,safety factor calculated for the slope in the debris is 1.1 which is well below the recommended value in the literature.The minimum safety factor for currently stable slopes which were cut at the eastern part of the failed area is 1.22 which is also less than that suggested in literature.Some remedial measures such as mini-pile or slope flattening are suggested after analyses to increase the factor of safety for this part below the settlement.
基金supported by National Natural Science Foundation of China (No. 41174085)Chinese Academy of Sciences (KZZD-EW-TZ-19)China Geological Survey (12120113101400)
文摘Site engineering seismic survey provides basic data for seismic effect analysis. As an important parameter of soil, shear-wave velocity is usually obtained through wave velocity testing in borehole. In this paper, the passive source surface-wave method is introduced into the site engineering seismic survey and practically applied in an engineering site of Shijingshan District. By recording the ubiquitous weak vibration on the earth surface, extract the dispersion curve from the surface-wave components using the SPAC method and obtain the shear-wave velocity structure from inversion. Over the depth of 42 m under- ground, it totally consists of five layers with interface depth of 3.31, 4.50, 7.23, 17.41, and 42.00 m; and shear-wave velocity of 144.0, 198.3, 339.4, 744.2, and 903.7 m/s, respectively. The inversion result is used to evaluate site classification, determine the maximum shear modulus of soil, provide basis for further seismic hazard analysis and site assessment or site zoning, etc. The result shows that the passive source surface-wave method is feasible in the site engineering seismic survey and can replace boreholes,shorten survey period, and reduce engineering cost to some extent.
基金Funding for this research was provided by the National Natural Science Foundation of China (42022052,42277138,and 52108337)the National Key R&D Program of China (2022YFC2803800)+1 种基金the Shandong Provincial Natural Science Foundation (ZR2020YQ29)UCL's Department of Civil,Environmental and Geomatic Engineering,and Ocean University of China.
文摘Ocean mining activities have been ongoing for nearly 70 years,making great contributions to industrialization.Given the increasing demand for energy,along with the restructuring of the energy supply catalyzed by efforts to achieve a low-carbon economy,deep seabed mining will play an important role in addressing energy-and resource-related problems in the future.However,deep seabed mining remains in the exploratory stage,with many challenges presented by the high-pressure,low-temperature,and complex geologic and hydrodynamic environments in deep-sea mining areas,which are inaccessible to human activities.Thus,considerable efforts are required to ensure sustainable,economic,reliable,and safe deep seabed mining.This study reviews the latest advances in marine engineering geology and the environment related to deep-sea min-ing activities,presents a bibliometric analysis of the development of ocean mineral resources since the 1950s,summarizes the development,theory,and issues related to techniques for the three stages of ocean mining(i.e.,exploration,extraction,and closure),and discusses the engineering geology environment,geological disasters,in-situ monitoring techniques,envi-ronmental protection requirements,and environmental effects in detail.Finally,this paper gives some key conclusions and future perspectives to provide insights for subsequent studies and commercial mining operations.
基金supported by China Geological Survey Project“Urban Geological Survey of Central Plains Urban Agglomeration”(1212011089048)
文摘Suitability evaluation of urban geological environment is an important basic work in city planning and construction. With Zhengzhou-Kaifeng area as the research area, this paper discusses AHP and fuzzy comprehensive evaluation methods to classify impact factors at different levels, makes a mixing evaluation of the basic factors and comprehensive factors so as to correct the uncertainty of the weight of the basic factors in the initial evaluation and establish the corresponding evaluation index system, and carries out urban geological environment suitability evaluation in study area. Furthermore, this paper partitions the suitability of the research area according to evaluation results into five zones. It puts forward opinions and suggestions for the construction of research area, which have certain practical significances.
基金supported by the Universitàdi Pisa (Darius, PRA 2018, PRIN 2008 and PRIN 2010-11 projects) to Michele Marronithe CNR-IGG,Pisa to Alessandro Ellero。
文摘A multidisciplinary approach combining multiscale geological-structural analyses(from field to microscale) and clay mineral transformations(clay mineralogy, illite and chlorite "crystallinity" and b cell dimension(b_(0)) of K-white mica) was adopted to unravel the tectono-metamorphic evolution of low-and very low-grade tectono-metamorphic units from the Intra-Pontide suture zone in northern Turkey. The mineralogical study allowed to better evaluate the structural stacking outlined during the geological mapping, leading to distinguish three tectono-metamorphic units, two in epizone(Daday and Emirkoy units) and one in anchizone(Cifter Unit) metamorphic conditions. The mesostructural and microstructural analyses suggest a polyphase tectonic-metamorphic evolution. The different macroscopic features observed between the two units characterized by the same epizone metamorphism, can be justified by the evidence that these metamorphic conditions were acquired during the last stages of exhumation in the Daday Unit, while they constrained the metamorphic-peak conditions in the Emirkoy Unit. Contemporary analyses and comparison between structural and mineralogical data have thus proven to be a powerful tool to investigate the low-grade and very low-grade metamorphic environments, allowing at the same time to solve the apparent contradictions deriving from the mineralogical study and to significantly improve the detail of the geological mapping in the field.
基金supported by the National Natural Science Foundation of China(grants No.40599420,40872114 and 41140028)the National Basic Research Program of China(grant No.2010CB833400)+1 种基金the Central University Research Foundation(grant No.310827152014)the State Key Laboratory of Loess and Quaternary Geology
文摘The Qinghai Lake in North China is the largest interior plateau lake in Central Asia, and is sensitive to climate change and the environmental effects of Tibetan Plateau uplift. An almost continuous 626 m long sediment core was drilled in an in-filled part of the southern lake basin in the Scientific Drilling at Qinghai Lake.
文摘Hydrogeological and hydrochemical assessments were carried out in Assin and Breman districts of Ghana. A multi-criteria approach was used in the assessment of the basin granitoids including;electrical resistivity survey, pumping test and water quality analysis. A total of twenty-five (25) representative boreholes were drilled, developed and pumped;obtaining data for aquifer hydraulic parameters estimation. Correlation analysis was used to determine relationships that exist between aquifer hydraulic parameters. Schoeller, Piper, Stiff plot and Gibbs diagrams were used to determine the hydrogeochemical facies, water types and the mechanism that control groundwater quality. The statistical analysis determined that aquifer hydraulic parameters discharge rate (Q), hydraulic conductivity (K) and Transmissivity (T) showed a strong positive correlation with specific capacity (Q/Sw) with R value 0.8462, 0.8738 and 0.8332 respectively. The K and T were respectively between 0.02 - 0.90 m/day and 0.36 - 13.47 m2/day with mean of 0.24 m/day and 3.03 m2/day respectively. The K values indicate a hydrogeological condition of aquiclude with relatively low permeability and medium water bearing capacity. The aquifer T magnitude is very low to low, groundwater potential is adequate for local water supply with limited and private consumption. All physicochemical parameters were within the permissible limits of Ghana Standards Authority (GSA) and World Health Organisation (WHO) except for apparent colour, pH, Fe and Mn. Distribution of major ions in groundwater samples was calculated and the general trend among cations and anions was found to be Ca2+ > Na+ > Mg2+ and Cl? > HCO3? > SO42? respectively. The study area shows five main water types namely;Ca-HCO3, Na-Mg-HCO3-SO4, Ca-SO4, Na-Cl and Mg-Na-Cl. Weathering of rock-forming minerals as the mechanism controlling the groundwater chemistry. Microbiological parameters were above the permissible limits. Groundwater is suitable for drinking after treatment with chlorination, aeration and slow sand filtration methods.
基金financially supported by the Key Special Project of National Natural Science Foundation of China (No.41941018)the Fundamental Research Funds for the Key Laboratory of Geotechnical and Underground Engineering (Tongji University)the Ministry of Education (Grant No.KLE-TJGE-B1905)。
文摘High-intensity and large-scale resource development seriously threatens the fragile ecological environment in the red soil hilly region in southern China. This paper analyzes the eco-geological environmental problems and factors affecting Ganzhou, a mining city in the red soil hilly region,based on field survey and literature. The ecogeological environment quality(EGEQ) assessment system, which covered 11 indicators in physical geography, mining development, geological hazards,as well as water and soil pollution, was established through multi-source data utilization such as remote sensing images, DEM(Digital Elevation Model), field survey and on-site monitoring data. The comprehensive weight of each indicator was calculated through the Analytic Hierarchy Process(AHP) and entropy method. The eco-geological environment assessment map was developed by calculating the EGEQ value through the linear weighted method. The assessment results show that the EGEQ was classified into I-V grades from excellent to worse, among which, EGEQ of I-II accounted for 29.88%, EGEQ of III accounted for 32.35% and EGEQ of IV-V accounted for 37.77%;the overall EGEQ of Ganzhou was moderate. The assessment system utilized in this research provides scientific and accurate results, which in turn enable the proposal of some tangible protection suggestions.
