• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.339-346
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• 1999

The stability of rock slope is considered to have a deep relation with types of rocks because types of rocks have their own typical weathering profiles, geological structures and characteristics of failures. Therefore it is essential for the evaluation of rock slope stability to analyze geological and engineering characteristics in rock mass. The data which collected from investigated slopes in sedimentary rock of Kyengsang Basin along highways were analyzed. Primary factors affecting slope stability in rock mass are: dips and strikes of slopes and discontinuities, shear strength of discontinuities, slope geometry and geological structures etc.

• Journal of Soil and Groundwater Environment
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• v.22 no.5
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• pp.63-70
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• 2017

Radon concentrations were measured in 250 groundwater samples collected from the Goesan area where uraniferous black slate and granites abundantly occur in the formations. The measured radon levels ranged from 0.90 to 7,218.7 Bq/L with the median value of 54.3 Bq/L, similar to the value measured in the nationwide survey in 4,853 wells (52.1 Bq/L). The median value was highest in the Cretaceous granite area (390.0 Bq/L) while it was as low as 20.0~58.8 Bq/L in the Ogcheon meta-sedimentary rock areas. About 23.6% of the total samples exceeded the WHO guideline value of 100 Bq/L established in 2011. The exceeding rate was 69.0, 39.4, and 7.0~13.7% in the Cretaceous granite area, Jurassic granite area, and Ogcheon meta-sedimentary rock areas, respectively.

• Economic and Environmental Geology
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• v.31 no.6
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• pp.519-526
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• 1998

A high-resolution seismic survey was conducted at the northeastern boundary of Pungam basin, one of the Cretaceous sedimentary basins in Korea. A 100 kg weight was used as an energy source and was found to be better than a sledge hammer in mapping deeper geologic structures. Several processing techniques such as f-k filtering, predictive deconvolution, and time-variant filtering are useful to enhance the signal-to-noise ratio by suppressing unwanted seismic energy. Four seismic units are recognized where many vertical faults are developed. The boundary fault between sedimentary rocks and Precambrian gneiss is identified along with a fracture zone of approximately 30 m wide. Bedding planes of the sedimentary rocks dipping westward are interpreted to be limbs of a syncline or volcanic flow. There faults and tilted bedding planes indicate that the basin had undergone significant tectonic deformation.

• Economic and Environmental Geology
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• v.5 no.3
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• pp.151-160
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• 1972

The region is composed of Cretaceous volcanic and sedimentary rocks; andesites and granites, It is clarified by the writers that most formations ever known as andesites are not igneous origin but hornfelsic sedimentary rocks. Refering to this fact, broad areas in the south-eastern part of the Kyeong-Sang Namdo which are colored as andesites in the geologic maps scale 1/50,000, published by Geological Survey of Korea should be rechecked. In this area, four granite plutons are isolated by the hornfelsic sedimentary formation, andesites and alluvium. Each plutons are zoned by the lithological facies.

• Economic and Environmental Geology
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• v.24 no.4
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• pp.393-398
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• 1991

The Buyeo-Cheongyang area, in the south-western area of Gyeonggi massif, comprises Precambrian and Mesozoic metamorphic and sedimentary rocks. The original rock of metamorphic rocks was studied by geochemical examination and statistical analyses of the trace elements in the gneisses, schists, shale and granitic rocks. Average abundance of Cu,Cr,Pb,Ni,Co,Mn,Li and Zn elements from gneisses have similar to those from shale and schists. However the gneisses have higher Cr,Ni,Co,Mn,Li abundance than those from the granite. Abundance range and frequency distribution of the trace elements in the gneiss show a marked trend sedimentary origin, that is, standard deviation have far the higer than that of igneous origin. Also it is wide dispersion and irregularly distribution. For that reason, this gneiss is regard as sedimentary original rocks with schists.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.481-496
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• 1996

The last Sea is a typical bark-arc basin consisting of basins, plateaus, ridges, and seamounts. The Ulleng Basin, located in the southwestern corner of the last Sea, contains thick Neogene sedimentary sequence. Analysis of over 2,500 km of single-channel seismic reflection data suggests that hemipelagic sedimentation prevailed over much of the basin during the late Miocene and pelagic sedimentation became more dominant during the Pliocene. During the Pleistocene terrigeneous sediments transported by turbidity currents and other gravity flows, together with continuous hemipelagic settling, resulted in well-stratified sedimentary layers. Influx of terrigenous sediments during the Pleistocene formed depocenters in the western and southern parts of the basins. In the Ulleung Interplain Gap, where the Ulleung Basin joins the deeper Japan Basin, sediment waves suggesting bottom current activities are seen.

• Tunnel and Underground Space
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• v.19 no.5
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• pp.450-462
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• 2009

To analyze the behavioral characteristics of rocks on indirect tests and uniaxial compressive strength, researchers have investigated 1417 pieces of rock block, which include igneous, metamorphic and sedimentary rocks in Korea. The same behavioral characteristics have been shown in every type of sedimentary rock and in the same species of rock in the case of Brazilian strength application. This suggests that correlations of rocks for geological considerations can lead to high reliability of the experimental results in case of an indirect method.

• Economic and Environmental Geology
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• v.32 no.1
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• pp.33-41
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• 1999

A new sedimentary basin is reported from the marine multi-channel seismic data which were acquired for the hydrocarbon exploration on the southwestern Korean continental shelf in 1970. Along the southeastern part of Line 1192, the about 60-km-long basin with the thickness of 0.55~1.1 s is observed on the near-trace gather. However, both new and previous 24-fold stack sections fail to show the basin image probably due to its rugged top beneath the shallow water. The boundary contact between the basement with the velocity of about 5200m/s and the basin filling with the velocities of 4300~4700 m/s is unclear. These velocites are calculated from the corresponding shot gathers. Compared with the Haenam Basin, a neighbouring onshore Cretaceous sedimentary basin, we interpret that the new basin includes the volcanics and volcaniclastic sequences deposited in the lacustrine environment. This nonmarine basin was possibly formed as the result of the tectonic movement during the Cretaceous, implying the wide occurrence of the Cretaceous basins over the southern Korean Peninsula as well as its southwestern continental shelf.

• Economic and Environmental Geology
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• v.33 no.3
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• pp.217-228
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• 2000

We use spectral correlation method to analyze gravity and magnetic anomalies of Euiseong Sub-basin for distribution of rock facies and gelogic structures. The analysis reveals distinct polarity between gravity and magnetic anomaly correlation ; intermediate to mafic intrusives, extrusives, and the Tertiary basin shows positive gravity (+G) and positive magnetic (+M) correlation. Granitic gneiss and felsic volcanics negative gravity 9-G) and negative magnetic (-M) correlation. The Palgongsan granite, felsic to mafic extrusives and Mesozoic granites are characterized by -G and + M correlation. +G and -M correlations in the sedimentary formations are interpreted by uplift of pre-Cretaceous basement rocks . The + G and + M correlation characteristics in northeastern part of Euiseong Sub-basin including the Tertiary sedimentary basin result from the uplift of crustal materials. Major axes of spectrally correlated amomalies have mostly NW-SE or NE-SW directions. The former is due to the intrusives along strike-slip faults, and the latter which is observed in sedimentary formations is related to geological structures of basement associated new insight into the boundary between Euiseong and Milyang Sub-basin.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.999-1008
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• 2009

A series of sedimentary rocks which are formed in the Tertiary are distributed around Samcheok(Samcheok-Pukpyoung basin), Younghae(Younghae basin), Pohang(Pohang basin), Gyeongju(Yangnam basin), Ulsan(Ulsan basin), Jeju(Seogyuipo formation) in the southern region of the Korean Peninsula. This study concerned with geological, geophysical, geotechnical properties of the unconsolidated rocks in the Pohang area. A consolidated rocks are classified as hard rock - soft rock - weathered rock - residual soil follows in degree of weathering. But unconsolidated rocks has soil properties as well as rock's at the same time. The results of field excursion, boring, borehole-logging, rock testing, geophysical survey, laboratory test are soft rock range, but the durability of the rock until the residual soil from the weathered rock. We accomplished the rock mass classification of the unconsolidated rocks.