• Journal of Soil and Groundwater Environment
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• v.26 no.1
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• pp.8-16
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• 2021

This study has evaluated the stabilization of As contaminated paddy and cultivated soils by pot experiments for rice and lettuce. Various ratios of limestone (L) and steel slag (S) were mixed with the soils in each pot. The soils were taken from before and after pot experiments, and analyzed for As extracted by sequentially (Wenzel method) and totally (aqua regia method).. Paddy soils amended with L (0.5%) and L (1.0%) + S (1.0%) showed increasing fraction 2 (specifically bound As) compared with control soil. Arsenic concentrations in rice grain grown on the amended soils decreased 14% and 12% compared with those on the control soil, respectively. According to sequential extraction of As in cultivated soils, the fractions 1~3 were decreased due to stabilization of As by the soil amendment, especially for S (1.0%), S (3.0%) and L (1.0%) + S (1.0%). In addition, relatively low As concentrations were found in lettuce grown on amended soils with L (0.5%) and L (1.0%) + S (1.0%). Therefore, it can be suggested that soil amendments with L (0.5%) or L (1.0%) + S (1.0%) were suitable for enhancing stabilization of As in the study area.

• Tunnel and Underground Space
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• v.32 no.5
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• pp.327-343
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• 2022

The standard work report for trucks was developed that records data on truck haulage operations in open-pit and underground mines, and to evaluate the performance of haulage operations. Work reports used in 5 mines in Korea was secured and analyzed, and items to be included in the standard work report were determined. By analyzing the formulas for key performance indicators (KPIs) proposed by the Global Mining Guidelines Group (GMG), it was possible to determine how to record time-related data. After selecting a limestone underground mine as a research area, the performance of haulage operations was evaluated using a standard work report. As a result, in terms of truck availability, uptime was 46.7%, and both physical and mechanical availability were 100%. In the case of utilization, use of availability was 88.2%, the asset utilization was 41.1%, and operating and effective utilization were 88.2% and 79.2%, respectively. Also, in terms of efficiency, operating efficiency was found to be 89.9%.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.521-529
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• 2022

Gravity exploration was conducted to determine the distribution of igneous complex related to lithium pegmatite in the Boam deposit of Uljin, Gyeongsangbuk-do, and the spatial relationship with the regional geology and ore bodies were studied. The gravity exploration result shows that the Boam deposit area is characterized by relatively low gravity anomaly that surrounds the deposit. The Boam deposit is located near the southwest-northeast directional boundary of gravity anomalies where igneous complex (granite gneiss) contacts with the Yuli and Wonnam groups in the southeast, Janggun limestone layers in the east-west direction, and Dongsugok metasedimentary rocks. While the western boundary in the southwest-northeast direction is relatively clear, there may also be unknown igneous complex that are not exposed on the surface at the eastern and southern boundaries because a relatively low gravity anomaly surrounds the deposit. The distribution characteristics of these hidden igneous complex will be used as useful data for predicting the distribution of the lithium pegmatite in the future.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.27-27
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• 2020

Daphne L. (Thymelaceae) comprises about 95 species distributing worldwide from N Africa, N India, SE Asia to E Asia and the coast of the Mediterranean of Europe. In Korea, five species of this genus have been described. In this study, we included four species (D. genkwa, D. pseudomezereum, D. kiusiana, D. jejudoensis) from Korea, excluding cultivated D. odora. The morphological characters through local surveys and the re-classification of the specimens collected in the Korea National Herbarium (KH) were carried out and distribution maps for each taxon were also prepared. The major characters include habit, trichomes in winter bud, leaf, and twig, phyllotaxis, inflorescence, size of calyx lobe and trichomes in the calyx tube, etc. The distribution map showed that D. genkwa is mainly distributed in the coastal area of Hwanghaenam-do, Pyeongannam-do, Jeollabuk-do and Jeollanam-do, whereas D. pseudomezereum is distributed in the limestone zone of Gangwon-do, Jeollabuk-do, and Gyeongsangbuk-do. Similarly, D. kiusiana is mostly found in Jeollanam-do, Gyeongsangnam-do, and Jeju-do. In addition, D. jejudoensis is known to be distributed in forests of Murueng, Andeok, and Seonheul-ri in Jeju-do, but recently, new habitat is discovered in the island forest areas of Jeollanam-do. However, some of these individuals showed the characteristics of D. kiusiana, thus before come to any conclusion detailed taxonomic review of D. jejudoensis and D. kiusiana is required.

• The Journal of the Petrological Society of Korea
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• v.17 no.4
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• pp.191-205
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• 2008

In order to use the geologic information data such as industrialization of rock resources, site enlargement and development planning, distributive ratios of rock types and geologic ages were obtained by the ArcGIS 9.2 program, and digital geologic and geographic maps of 1:250,000 scale, in the Chungbug, Chungnam and Daejeon areas, respectively. In the Chungbug area, 64 rock kinds are developed and their geologic ages can be classified into 8 large groups. In the geologic ages, the ratios are decreasing in the order of Jurassic, Precambrian, Age-unknown, Cretaceous, Quaternary, Cambro-Ordovician and Carboniferous-Triassic ages, all of which comprise most ratios of 98.48% in the area. In the rock types, the ratios show the decreasing order of Jurassic Daebo granite, Precambrian banded gneiss of Gyeonggi metamorphic complex, Cretaceous biotite granite, Quaternary alluvium, Great limestone group, Lower phyllite zone and Meta-sandy rock zone of age-unknown Ogcheon group, Triassic Cheongsan granite, Precambrian granitic gneiss of Gyeonggi gneiss complex, Pebble bearing phyllite zone of age-unknown Ogcheon group and biotite gneiss of Sobaegsan metamorphic complex, all of which comprise the prevailing ratio of 84.27% in the area. In the Chungnam area, 35 rock types are developed and their geologic ages can be classified into 6 large groups. In the geologic ages, the ratios are decreasing in the order of Precambrian, Jurassic and Quaternary ages, which occupy the prevailing ratio of 87.55% in the area. In the rock types, the ratios show the decreasing order of Jurassic Daebo granite, Precambrian banded gneiss of Gyeonggi metamorphic complex, Quaternary alluvium, Precambrian granite and granitic gneiss of Gyeonggi gneiss complex, Cretaceous acidic dykes, Lower phyllite zone and Pebble bearing phyllite zone of age-unknown Ogcheon group and Quaternary reclaimed land, which occupy the ratios of 74.28% in the area. In the Daejeon area, 11 rock types are developed and their geologic ages can be classified into 5 large groups. In the ages, the ratios are decreasing in the order of Jurassic, Age-unknown and Quaternary, which occupy most ratios of 93.40% in the area. In the rock types, the ratios show the decreasing order of Jurassic Daebo granite, Quaternary alluvium and Lower phyllite zone and Pebble bearing phyllite zone of age-unknown Ogcheon group, which occupy the prevailing ratios of 91.09% in the area.

• Korean Journal of Plant Resources
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• v.29 no.2
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• pp.241-263
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• 2016

This study was carried out to survey the vascular plants on Mt. Seokbyeongsan (1,055 m) and provide a basis for the conservation and management of plant resources. The vascular plants were surveyed from March to October 2015. The flora on Mt. Seokbyeongsan was classified as follows: 102 families, 295 genera, 454 species, 4 subspecies, 51 varieties, 7 forms, and a total of 516 taxa. Endemic plants included 17 families, 24 genera, 25 species, 1 variety, and a total of 26 taxa. The Korea Forest Service assignment of rare plants, including 21 families, 33 genera, 33 species, 3 varieties, and a total of 36 taxa, was investigated. Moreover, the Ministry of Environment assignment of rare plants, including 13 families, 17 genera, 17 species, 1 variety, and a total of 18 taxa, was investigated. Floristic special plants in the surveyed area were divided into five classes (Classes I-V): 42 taxa of Class I, 26 taxa of Class II, 35 taxa of Class III, 20 taxa of Class IV, and 9 taxa of Class V for a total of 132 taxa. Naturalized plants were 18 taxa, and plants threatened by climate change were 48 taxa.

• Geophysics and Geophysical Exploration
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• v.9 no.4
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• pp.271-278
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• 2006

Investigations of underground cavities are required to provide useful information for the reinforcement design and monitoring of the ground subsidence areas. It is, therefore, necessary to develop integrated geophysical techniques incorporating different geophysical methods in order to accurately image and to map underground cavities in the ground subsidence areas. In this study, we conducted geophysical investigations for development of integrated geophysical techniques to detect underground cavities at the field test site in the ground subsidence area, located at Yongweol-ri, Muan-eup, Muan-gun, Jeollanam-do. We examined the applicability of geophysical methods such as electrical resistivity, electromagnetic, and microgravity to cavity detection with the aid of borehole survey results. The underground cavities are widely present within the limestone bedrock overlain by the alluvial deposits in the test site where the ground subsidences have occurred in the past. The limestone cavities are mostly filled with groundwater or clays saturated with water in the site. The cavities, thus, have low electrical resistivity and density compared to the surrounding host bedrock. The results of the study have shown that the zones of low resistivity and density correspond to the zones of the cavities identified in the boreholes at the site, and that the geophysical methods used are very effective to detect the underground cavities. Furthermore, we could map the distribution of cavities more precisely with the study results incorporated from the various geophysical methods. It is also important to notice that the microgravity method, which has rarely used in Korea, is a very promising tool to detect underground cavities.

• Korean Journal of Environment and Ecology
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• v.36 no.2
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• pp.177-201
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• 2022

Following the adoption of the global plant conservation strategies at the Conference of the Parties for Biodiversity Conservation, diligent actions to achieve each targets are actively carried out. In particular, the need for ecological conservation research to achieve targets 2 and 7 of GSPC-2020 has increased. The priority taxa to accomplish the objectives of GSPC-2020 are rare and endemic plants. In particular, endemic plants with limited distribution in specific regions are evaluated to face a high risk of extinction. To address the necessity to preserve endemic plants, we investigated the distribution of Prunus choreiana H. T. Im, a Korean endemic plant. After that, we examined the vegetational environment of the habitat of P. choreiana and evaluated its population structure. The productivity of its fruits and the effects of pollinators on fruit production were evaluated as well. The fruiting ratio was calculated based on the number of flowers produced. Lastly, we observed the annual growth characteristics of P. choreiana. The habitats of P. choreiana did not show a specific type of vegetation. All of them were located in a limestone area of Gangwon-do in the central Korean Peninsula and occupied a site where the coverage of the tree layer and the sub-tree layer was not high or did not exist. The population structure of P. choreiana contained a high proportion of mature plants capable of producing fruits and a low proportion of seedlings and Juvenile plants. We found that the production of fruits required pollinators and was affected by the performance of each plant. Although P. choreiana produces many flowers, only a maximum of 20% and only 2-6% on average bear fruits. These flowering characteristics may be due to pollinators' low abundance and activity during the flowering season (between mid-March and early April), suggesting that many flowers are needed to attract more pollinators. We rarely observed the re-establishment of seedlings in the population of P. choreiana. Despite that, we predict the population to persist owing to its long lifespan and periodic production of numerous fruits. However, if the tree layer and sub-tree layer in competing status with P. choreiana increase their crown density, they are expected to inhibit the growth of P. choreiana and affect the risk of its extinction. Therefore, the current changes in the vegetational environment of the habitats are expected to decrease the number and extent of P. choreiana in the long term. The results of this study may serve as primary and important data necessary for the achievement of GSPC-2020 objectives.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.29-50
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• 2003

Physicochemical Properties of acid mine water of the Chonam-ri Creek and the Sagok-ri Creek in the Kwangyang Au-Ag mine area were determined using geochemical approaches. Metal contamination (Cd, Cu, Pb, Zn) is more serious in the Chonam-ri Creek than in the Sagok-ri Creek. However, the contents of Al and Fe is higher in the Sagok-ri Creek. Such differences between the two creeks probably reflect the abundance and composition of ore minerals. The attenuation processes for acid mine water in both creeks were investigated. In the Chonam-ri Creek, a small retention pond which contains limestone plays an important role in the removal of heavy metals by adsorption or coprecipitation due to increase of pH. The capacity of metal scavenging in this pond depends on the seasonal variation of inflow volume. Reddish yellow precipitates sampled in the Chonam-ri Creek were analyzed by XRD, SEM-EDS, EPMA, and chemical decomposition. The precipitates mainly consist of goethite and are also enriched in Al, Mn, Cu and Zn. This inditates that precipitation of goethite is important for scavenging those trace elements, possibly due to adsorption or coprecipitation. In the Sagok-ri Creek, on the other hand, hydrologic mixing of uncontaminated tributaries results in removal of heavy metals with iron hydroxides precipitation due to the pH increase. The mechanisms proposed for metal attenuation at the confluence between contaminated mine water and uncontaminated tributary water are also explained by the property-property plots.

• Economic and Environmental Geology
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• v.6 no.3
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• pp.171-182
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• 1973

Gemorphological and photogeological techniqes are applied to the problem of geological mapping of a semi-arid area, Albudeite, Southeastern Spain. As a result of this, a geological and surface materials map is made which shows the upper Miocene formation, which mainly consists of marl, limestone and sandstone, is further subdivided into three members, i. e. lower, middle and upper, and the post-Miocene deposits were differentiated into seven stratigraphic units, and mapped. The relationships between geology, landforms and land comlexes previously reognized have been reviewed. The methods adopted have proved to be valuable in interpreting and mapping a compex relationship in which highly variable bedrock outcrops and shallow surface materiales produced under sub-aerial conditios.