• Journal of The Geomorphological Association of Korea
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• v.26 no.4
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• pp.107-121
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• 2019

This study documents the distribution of (active) faults around the southern part of the Yangsan Fault and the Moryang Fault and the middle part of the Dongrae Fault. For this objective, we extracted lineaments and fault-related landforms by analyzing aerial photos and digital elevation models and with the result of fieldwork on fault-relating features of the Quaternary landforms. Geomorphological techniques for active fault study are not only preliminary but also essential methods because, in general, an active fault can be defined only with fault-deformed Quaternary sediments when there is no way to detect precise timing of faulting. Therefore, geomorphological interpretation in active fault research is necessary to determine the extent, direction, termination and timing of fault. This study addresses the results of such geomorphological analysis and geomorphic markers for tracing the active faults in the study area. It is plan to investigate with geophysical and geological techniques the sites referred in this study.

• Tunnel and Underground Space
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• v.30 no.5
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• pp.462-472
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• 2020

Rock classification is fundamental discipline of exploring geological and geotechnical features in a site, which, however, may not be easy works because of high diversity of rock shape and color according to its origin, geological history and so on. With the great success of convolutional neural networks (CNN) in many different image-based classification tasks, there has been increasing interest in taking advantage of CNN to classify geological material. In this study, a feasibility of the deep CNN is investigated for automatically and accurately identifying rock types, focusing on the condition of various shapes and colors even in the same rock type. It can be further developed to a mobile application for assisting geologist in classifying rocks in fieldwork. The structure of CNN model used in this study is based on a deep residual neural network (ResNet), which is an ultra-deep CNN using in object detection and classification. The proposed CNN was trained on 10 typical rock types with an overall accuracy of 84% on the test set. The result demonstrates that the proposed approach is not only able to classify rock type using images, but also represents an improvement as taking highly diverse rock image dataset as input.

• Journal of The Geomorphological Association of Korea
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• v.27 no.2
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• pp.1-17
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• 2020

This study evaluated a debris landform distribution potential area map in the southwest region of the Korean peninsula. A GIS spatial integration technique and logistic regression method were used to produce a distribution potential area map. Seven topographic and environmental factors were considered for analysis and 28 different data set were combined and used to get most effective results. Moreover, in an accuracy assessment, the extracted results of the Distribution Potential area were evaluated by conducting a cross-validation module. Block stream showed the highest accuracy in the combination No. 6, and that DEM (digital elevation model) and TWI (topographic wetness index) have relatively high influences on the production of the Block stream Distribution Potential area map. Talus showed the highest accuracy in the combination No. 13. We also found that slope, TWI and geology have relatively high influences on the production of the Talus Distribution Potential area map. In addition, fieldwork confirmed the accuracy of the input data that were used in this study, and the slope and geology were also similar. It was also determined that these input data were relatively accurate. In the case of angularity, the block stream was composed of sub-rounded and sub-angular systems and Talus showed differences according to the terrain formation. Although the results of the rebound strain measurement using a Schmidt's hammer did not shown any difference in topographic conditions, it is determined that the rebound strain results reflected the underlying geological setting.

• Journal of The Korean Association For Science Education
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• v.37 no.3
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• pp.465-481
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• 2017

This study is a research synthesis analyzing how field geology education is conducted in domestic and foreign countries in the recent 20 years and how it reflects the characteristics of authentic geologic inquiry. For these purposes, we first drew five elements of inquiry in field geology (observation, representation, abductive reasoning, spatial thinking, and diachronic thinking) considering the field geologists' actual research method as well as its pedagogical significance in science education. We developed analysis criteria for field geology education. The 53 cases were analyzed based on each element of inquiry in field geology and its sub-elements, and also the tendency of overall elements. As a result, observation and representation were included in most cases, but there appeared less frequency in order of abductive reasoning, spatial thinking, and diachronic thinking. For observation, the ratio of purposive observation and autonomous observation is high. For representation, both visualizing and linguistic type of representation and free-form representation appear frequently. For abductive reasoning, the step of generating hypothesis is often included and the hypothesis tends to be about the geological formatting process. For spatial thinking, type of self-location and perception of the spatial configuration of the structure appear at a high rate. For diachronic thinking, type of stratigraphic sequence is the most frequent. The proportions of the cases including three or more elements of inquiry in field geology consist 87% of the total. We suggested implications for improving geological fieldwork as authentic science inquiry in the future.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.381-393
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• 2014

Seismic reflection data are integrated with fieldwork data in order to understand startigraphy, structural geology and hydrocarbon potentials of Cretaceous strata in the Mesopotamian basin, Northeastern Iraq. Cretaceous strata in the basin divided into the Qamchuqa, Kometan, Bekhme and Shiranish formations, which are composed of carbonates deposited in shallow marine environment. The geological structures in these formations are mainly recognized as thrusts, detachment folds, fault propagation folds and fault bend folds. As well, NW-SE trending fractures are regularly developed, and are horizontal or perpendicular to the structures. The distribution and frequency of fractures are related to the development of the thrusts. In terms of hydrocarbon potentials, Cretaceous strata in the basin have limited capacities for source rocks and seal rocks due to the lack of organic carbon content and the well-developed fractures, respectively. Although these carbonates have limited primary porosity, however, development of the secondary porosity derived from the fractures contributes to enhance the reservoir quality. Most important factor for the reservoir quality of Cretaceous strata seems to be the frequency and connectivity of fractures relative to locations of folds and faults. The results delineated in this study will use as reference for recognizing stratigraphy and structures of Cretaceous strata and will provide useful information on hydrocarbon potentials of Cretaceous strata in the Mesopotamian basin, NE Iraq.