• Economic and Environmental Geology
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• v.30 no.4
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• pp.363-369
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• 1997

As a part of the study to know the deep geological structure of the Ogcheon Zone. gravity survey is performed along the survey line of which direction is roughly perpendicular to major faults of the Zone. Recent studies for petrology. geochemistry. and structural geology in south-western Ogcheon Zone are outlined. Raw gravity data are corrected to obtain Bouguer anomalies and the anomalies are interpreted to obtain subsurface structures along the survey line. The subterranean density discontinuities determined from the power spectrum method are appeared at depths of 15.4 km and 2.8 km. It is considered that the depth of 15.4 km indicates the boundary between upper and lower crust. Probably the depth of 2.8 km represents the boundary between upper volcanic formations and granites. Alternatively. the observed Bouguer anomalies are interpreted in terms of lateral density variation model. Finally. the subterranean geological structure to satisfy the Bouguer anomalies is presented through the iterative forward method in which results obtained from surface geological informations and from the inverse method are adopted as an initial model.

• Steel and Composite Structures
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• v.47 no.4
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• pp.451-454
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• 2023

Landslides are one of the natural disasters that cause a lot of financial and human losses every year It will be all over the world. China, especially. The Mainland China can be divided into 12 zones, including 4 high susceptibility zones, 7 medium susceptibility zones and 1 low susceptibility zone, according to landslide proneness. Climate and physiography are always at risk of landslides. The purpose of this research is to prepare a landslide hazard map using the Hierarchical Analysis Process method. In the GIS environment, it is in a part of China watershed. In order to prepare a landslide hazard map, first with Field studies, a distribution map of landslides in the area and then a map of factors affecting landslides were prepared. In the next stage, the factors are prioritized using expert opinion and hierarchical analysis process and nine factors including height, slope, slope direction, geological units, land use, distance from Waterway, distance from the road, distance from the fault and rainfall map were selected as effective factors. Then Landslide risk zoning in the region was done using the hierarchical analysis process model. The results showed that the three factors of geological units, distance from the road and slope are the most important have had an effect on the occurrence of landslides in the region, while the two factors of fault and rainfall have the least effect The landslide occurred in the region.

• Journal of the Korean earth science society
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• v.30 no.7
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• pp.869-882
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• 2009

The purpose of this study is to develop teaching materials for geological fieldwork around the area of Mai Mountain and to analyze the responses of elementary teachers as to the application of fieldwork. The site of geological fieldwork, Mai Mountain area, is located around the Maisan Provincial Park of Jinan-gun, Jeonbuk Province where a large-scale sedimentary succession in the era of Cretaceous is shown. It provides an easy access to distinct outcrops around the provincial park. The sequences reveal different kinds of sedimentary rocks and various sedimentary structures, and provide information of the lacustrine sedimentary environments of the Cretaceous. In addition, metamorphic rocks and structures formed at the margin of the basement and the basinal fault as well as a sedimentary sequence of the Quaternary formed in a modern fluvial stream are observable. A 4-step fieldwork procedure was applied to a group of 13 elementary teachers. Through questionnaire and interview, results showed that (a) the geological fieldwork and materials were effective to positively increase science teaching from the participating teachers, and that (b) there is a great need of the development of various fieldwork sites and teaching materials that promote active fieldwork for students to have their lived experience and knowledge gain. It is suggested that teacher education programs be able to provide active fieldwork for elementary inservice teachers to properly carry out a geological fieldwork for their students.

• Economic and Environmental Geology
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• v.29 no.3
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• pp.345-355
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• 1996

The effectiveness of various electrode configurations in horizontal mappings and 1-D inversions of vertical sounding data for delineating 2-D structures was studied. Apparent resistivity values of three point, dipole-dipole, Wenner, and Schlumberger mappings were simulated for such structures as vertical dyke, tabular prism, buried vertical fault, ramp and complex structure by finite difference method (FDM) and they were compared with each other. Also 2-D cross sections for three structures obtained by interpolation of 1-D inverted sounding data in terms of three layers were compared for Schlumberger and Wenner arrays. On these cross sections, horizontal and vertical resistivity interfaces of the 2-D structures are revealed relatively clearly. Apparent resistivity curves of Schlumberger mapping show vertical resistivity discontinuities very well. On the whole, Schlumberger array is superior to the other arrays in electric sounding as well as mapping. This study clearly indicates that interpretations of 2-D structures based on 1-D inversion are possible.

• Journal of the Korean earth science society
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• v.42 no.3
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• pp.311-324
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• 2021

Recently, ten geosites have been considered in Hwaseong for endorsement as national geoparks, including the Jebudo, Gojeongri Dinosaur Egg Fossils, and Ueumdo geosites. The Jebudo geosite in the southern part of the Seoul metropolitan area has great potential for development as a new geoscience educational site because it has geological, geographical (landscape), and ecological significance. In this study, we described the geological characteristics through field surveys in the Jebudo geosite. We evaluated its potential as a geo-education site based on comparative analysis with other geosites in Hwaseong Geopark. In addition, we reviewed the practical effect of field education at geosites on the essential concepts and critical competence-oriented education emphasized in the current 2015 revised science curriculum. The Jebudo Geosite is geologically diverse, with various metamorphic rocks belonging to the Precambrian Seosan Group, such as quartzite, schist, and phyllite. Various geological structures, such as clastic dikes, faults, joints, foliation, and schistosity have also been recorded. Moreover, coastal geological features have been observed, including depositional landforms (gravel and sand beaches, dunes, and mudflats), sedimentary structures (ripples), erosional landforms (sea cliffs, sea caves, and sea stacks), and sea parting. The Jebudo geosite has considerable value as a new geo-education site with geological and geomorphological distinction from the Gojeongri Dinosaur Egg Fossils and Ueumdo geosites. The Jebudo geosite also has opportunities for geo-education and geo-tourism, such as mudflat experiences and infrastructures, such as coastal trails and viewing points. This geosite can help develop diverse geo-education programs that improve key competencies in the science curriculum, such as critical thinking, inquiry, and problem-solving. Furthermore, by conducting optimized geo-education focused on the characteristics of each geosite, the following can be established: (1) the expansion of learning space from school to geopark, (2) the improvement of understanding of specific content elements and linkage between essential concepts, and (3) the extension of the education scope throughout the earth system. There will be positive impacts on communication, participation, and lifelong learning skills through geopark education.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.279-291
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• 2010

To characterize geological features in study area for high-level radioactive waste disposal research, KAERI (Korea Atomic Energy Research Institute) has been performing the several geological investigations such as geophysical surveys and borehole drilling since 1997. Especially, the KURT (KAERI Underground Research Tunnel) constructed to understand the deep geological environments in 2006. Recently, the deep borehole of 500 m depths was drilled to confirm and validate the geological model at the left research module of the KURT. The objective of this research was to identify the geological structures around KURT using the data obtained from the deep borehole investigation. To achieve the purpose, several geological investigations such as geophysical and borehole fracture surveys were carried out simultaneously. As a result, 7 fracture zones were identified in deep borehole located in the KURT. As one of important parts of site characterization on KURT area, the results will be used to revise the geological model of the study area.

• The Journal of Engineering Geology
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• v.22 no.1
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• pp.1-13
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• 2012

The purpose of this work is to gain a better understanding of the interrelationships between geological structures and slope failure in sedimentary rocks. In the studied slopes, construction-related slope failure could only be observed on the south-dipping slopes. This indicates that slope stability may be dependent on the angular relationships between the dip direction of bedding and the orientation of the slope. Slope failure continued, post-construction, around large fault zones in the studied outcrop; these fault damage zones are, however, not easily recognized in the field. Here we suggest a new method that uses accumulated fracture density to precisely identify fault damage zones. Multiple-faced slopes are now increasingly being exposed during large-scale construction projects in South Korea. This multiple-faced slope analysis indicates that the stability of a slope should be evaluated by identifying domains, through the analysis of possible slopes and their angular relationships with bedding and other discontinuities, prior to construction. Therefore, careful consideration of geological structures such as bedding and other discontinuities, and their angular relationships during the design of cuttings through sedimentary rocks, will increase the efficiency of construction and enable the safe construction of more stable slopes that will retain their stability after construction.

• Economic and Environmental Geology
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• v.18 no.4
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• pp.369-379
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• 1985

The geological structures and some of the stratigraphy in the area studied are being thought to be ambiguous and controvertible. The present study intended to clarify these ambiguities by correct interpretation of the geological structures and lithostratigraphy of the area concerned. The so-called "Sambangsan formation", which was designated as an unknown age by the Taebaksan Geological Investigation Corps (1962) and as the mid Cambrian age by T. Kobayashi (1966) and I.S. Kim (1983), has been determined by the present study as the $Hongj{\breve{o}}m$ series of Carbo-Permian age resting unconformably on the Cambro-Ordovician limestone formations. This determination was supported by conodont study concurrently carried out by I.S.Kim. The so-called "Daehari formation", which was renamed by the later study group after the original "Sambangsan formation" distributed in the area from southwest of Sambangsan toward southwest to $Juch{\breve{o}}n$, possesses more or less the same lithlogy as "Sambangsan formation" of the old designation in the eastern of the area, but different lithology in the western localities where Sadong formation, the basal sandstone member of the Kobangsan formation and the green shale member of the Nokam formation are cropped out. The narrow belt of the complex mixture of the $Py{\breve{o}}ngan$ group in-between limestone formations extending over 16km with a width of 500m to 1000m was formed by the faults: the northern boundary with the limestone formations is a fault contact all the way through entire area and the southern boundary is either fault contact in most of the area and unconformity in some other area. The $Hongj{\breve{o}}m$ formation on the Mt. Sambangsan shows rather steeply dipping nearly isoclinal folds which plunges $10^{\circ}$ to $20^{\circ}$ southward. There are also field evidences that the limestone formations distributed in both north and south of the Hongjom formation (erstwhile "Sambangsan formation") along the Sambangsan ridge are the same formations and show the same folding as the $Hongj{\breve{o}}m$ formation. Therefore, these limestone formations should be rezoned in the light of the new structural interpretation although they were differently designated in the previous studies as $Py{\breve{o}}ngchang$ and $Y{\breve{o}}ngw{\breve{o}}l$-type of the Joson Group. The structures developed in the area mostly faults, which acted as one of the guides for the new interpretation of the geology and structure of the area are described and shown on the geologic map.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.83-92
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• 2005

The aim of this study was to investigate damage conditions of cut slope structures due to acid rock drainage (ARB) and to assess the acid production potential of various rocks. Acid rock drainage is produced by the oxidation of sulfide minerals contained in coal mine zone and mineralization belt of Pyeongan supergroup and Ogcheon group, pyrite-bearing andesite, and Tertiary acid sulfate soils in Korea. Most of cut slopes producing ARB have been treated with shotcrete to reduce ARD. According to the field observations, ARD had an adverse effect on slope structures. The corrosion of shotcrete, anchors and rock bolts and the bad germination and growth diseases of covering plants due to ARD were observed in the field. The concentration of heavy metals and pH of ARD from cut slope exceeded the environmental standard, indicating a high potential of environmental pollution of surrounding soil, surface water and ground water by the ARD. According to acid base accounting (ABA) of the studied samples, hydrothermally altered volcanic rocks, tuffs, coaly shales, tailings of metallic mine had a relatively high potential of acid production but gneiss and granite had no or less acid production potential. It is expected that the number of cut slopes will increase hereafter considering the present construction trend. In order to reduce the adverse effect of ARD in construction sites, we need to secure the data base for potential ARD producing area and to develop the ARD reduction technologies suitable.

• Journal of the Korean earth science society
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• v.35 no.6
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• pp.412-421
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• 2014

In order to develop an effective mineral exploration technique, this study was carried out about the potential mapping of Gagok mine. The deposit model of Gagok mine is widely known. Based on the deposit model, we constructed mining indicator indices using related igneous rocks, faults, and carbonate rocks. By analyzing the spatial correlation between ore and indicator index structures, we decided the weighting values of indices according to the distance from the index structure. The 3D potential mapping was performed using 3D geological model and geological indices. The analyzed potential map verified that the locations and patterns of high potential regions of the results were well matched with those of the known ore bodies. Using the potential mapping results, we could effectively predict the location of a high potential area that has similar geological settings with ore.