• Journal of the Korean earth science society
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• v.25 no.4
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• pp.270-276
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• 2004

Multi-channel Analysis of Surface Waves (MASW) and Seismic Cone Penetration Test (SCPT) have been recently developed to obtain S-wave velocity profiles which were conventionally investigated by a down-hole seismic survey. For unconsolidated sedimentary sites, we studied these three methods, and compared the results with a drilling log. All the methods showed that the changes in the S-wave velocities were consistent with the changes in the sedimentary facies. In addition, the SCPT was most sensitive to changes in sedimentary facies among the three profiles. The results of the SCPT showed that there exists a low velocity zone, which is mainly composed of clayey sand, at the depth of 8${\sim}$12m in the sediments.

• The Korean Journal of Petroleum Geology
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• v.7 no.1_2 s.8
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• pp.7-12
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• 1999

A new high-resolution rnagnetotelluric (MT) survey was conducted for pull-apart basin analysis (Cretaceous Eumsung Basin), combined with surface sedimentological results. Two cross-basinal MT profiles represent an asymmetric form with a subbasin in the southeastern part. These basinal architectures are well compatible with paleoflow directions and facies transitions of surface sedimentology. The results also suggest that the basin fills reflect pull-apart opening with rapid subsidence of the central blocks. Combined with the surface sedimentological data on asymmetric lithofacies distribution, facies transitions, and paleoflow directions of the alluvio-lacustrine systems, the MT data help explain basin-fill processes during the basin formation. For petroleum exploration and basin analysis, the high-frequency MT technique can be a useful substitute for the costly burden of a seismic-reflection survey on land.

• 한국해양학회지
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• v.28 no.4
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• pp.259-271
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• 1993

The distributions of bottom sediments and the depositional processes on the continental shelves of Korean Seas are interpreted. Generally the continental shelf sediments can be classified into the sand-facies and mud-facies, showing the typical bimodal size distributions Most of the sandy and gravelly sediments on the outer shelf floor are interpreted as "relict" sediments that were deposited during the last glacial times when the sea level was lower than the present. On the other hand the muddy sediments on the inner shelf area are interpreted as "recent" sediments that are deposited under the present environment conditions. It is understood that most of the fine materials cannot escape the inner shelf area due to the strong tidal and coastal fronts, and are transported eastward from the West Sea along the southern coast of Korean Peninsula. The dark-colored muddy sediments in the Hupo Basin of the East Sea are, however, considered to be "relict" sediments. In the midshelf area fine materials are mixed with the relict coarse sediments, and some of the relict sediments are continuously reworked under the present environmental conditions forming the "palimpsest" sediments.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.3
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• pp.103-111
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• 1998

This paper reports the sediment geochemistry and its relation to the grain size distribution in Kyeonggi Bay, Korea. Sediment samples were collected from 90 stations during the cruise crossing the bay in December 1995. Variables investigated were the sediment grain size, organic carbon content, and concentrations of AI, Fe, Mn, V, Co, Ni, Cr, Zn and Cu in the sediment. We followed the change in these variables by comparing the data obtained from this region in 1981. Distribution pattern of sediment grain size was modified from that in 1981 in some places. Near the Shihwa Dike which was completed in 1994, sediment had got finer grained. Sediment facies changed from fine to mixed facies near Youngjong Island where the tidal flat has been reclaimed for airport construction. Contents of organic matter and metals in the sediment were mostly dependent upon the sediment grain size, but an exception was found in the harbor area. The sediment in the Incheon North Harbor showed higher accumulation of organic matter and metals such as Ni, Cr, Zn and Cu.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1203-1211
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• 2010

In order to study geology and sediment characteristics in Danghang Bay area, surface geological survey, SBP (sub-bottom profiler) survey, and sediment analysis were conducted. Danghang Bay area has a closing coast surrounded by land, and surface layer are covered by mud and sandy mud. Sedimentary facies of the surface layer consists of Mm and Mms facies. A SBP seismic survey shows that gas bearing sediments might be spread throughout the sediment layers, so that it seems to be hard to find acoustic basement and gas seeps are easily found throughout the survey lines. The gas trapped in the sediments may be related to the high organic contents of the sediment, and the thick mud layer may restrain the gas from releasing.

• The Korean Journal of Quaternary Research
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• v.24 no.1
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• pp.35-45
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• 2010

The aims of this study are to clarify the geomorphological development of a alluvial plain and discuss the vegetation environments and agriculture activities in the Wangpo-River alluvial plain at Neungsan-ri, Buyeo by analyzing geomorphological classification, sedimentary facies and age datings. The alluvial plain at Wangpo-River was formed by the influences of Geum-River with the sea-level rising during the Holocene. The basin of Wangpo-River consists of natural levees, back marsh-type alluvial plains, valley plains and hills. The natural levees by Geum-River largely distributes at the area where Wangpo-River flows to Geum-River and the alluvial plains at the middle and lower reach are the back marsh areas of Geum-River. Moreover, the area along Wangpo-River show higher contents of coarse materials and thinner peat sediments than the back marsh. The lower sandy deposits in the alluvium of Wangpo-River was formed with the influences of human in the Bronze Age during the sea level falling and the peaty deposits was formed due to the water level rising of Wangpo-River during the sea level rising in the early Iron Age.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.14-30
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• 2000

Hierarchically controlled sequence stratigraphic analysis shows that the Lower Ordovician mixed carbonate-siliciclastic Mungok Formation, Korea consists of three depositional sequences: T1, T2, and T3. Sequence boundaries are generally marked by abrupt transition from coarse-grained shallow-water carbonates to fine-grained deeper-water carbonates mixed with fine-grained siliciclastics, and show indication of subaerial exposure such as karstification. Within this sequence stratigraphic framework, facies characteristics indicate that the Mungok sequences were mostly deposited in subtidal ramp environments. High-frequency cycles consist of upward-shallowing facies successions. Cycles of shallow-water and basinal deposits are not represented well, probably due to cycle amalgamation. Cycle stacking patterns do not show a consistent thickness change that reflects a large-scale sea-level change due to unfilled accommodation space. The Mungok sequences show that many factors including relative sea-level change and topography are involved in controlling sequence development on carbonate ramps. The depositional setting evolved from the high-energy ramps in the sequences T1 and T2 into the low-energy ramp in the sequence T3. Topography is interpreted to have been responsible for the different energy regimes of the carbonate ramps in the Mungok sequences. The high ramp gradient in the sequences T1 and T2 seems to be caused by space-time-dissociated differential sedimentation resulting in spatially narrow distribution of sediment filling, which in turn may be related to high rate of relative sea-level change. In contrast, low ramp gradient was maintained in the sequence T3 during slow changes of relative sea level resulting in broad distribution of sediment filling.

• Journal of the Korean earth science society
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• v.26 no.8
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• pp.809-820
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• 2005

The fluvial sequence developed along the channel margin of meander bends in the midstream of the Yeongsan River consists of channel deposits at the bottom and overbank deposits at the top, and shows a fining-upward trend. The fluvial deposits consist of 7 sedimentary facies, and facies association forms 7 architectural elements. The channel deposits formed as channel bar or point bar. The channel bar deposits consisted of architectural element of gravel bedform were formed by channel lag deposits within the channel; whereas, the channel bar deposits consisted of architectural elements of downcurrent-dipping inclined strata sets, cross-stratified and horizontally stratified sets, and horizontally stratified sets were formed by downstream migration of sand wave or downstream transport of sand by traction current in the upper flow regime conditions within the channel. The point bar deposits consist of architectural elements of down current-dipping inclined strata sets, horizontally stratified sets, cross-stratified and horizontally stratified sets, and laterally inclined and horizontally stratified sets. These architectural elements are thought to have been formed by the combined effects of the migration of sand dunes and the formation of horizontal lamination in the upper flow regime plane bed conditions. The overbank deposits consist of the architectural elements of overbank fine and sand sheet and lens. The overbank fines were formed by settling of mud from slackwater during flooding over floodplain whereas the sand sheet and lens were formed by traction of sands introduced episodically fiom channel to the overbank during flooding.

• Journal of the Korean Geographical Society
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• v.48 no.6
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• pp.837-855
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• 2013

The remains and relics such as wood vessel, shell middens and acorn hollows related to marine environments were excavated at Bibong-ri, Changnyeong-gun, Gyeongsangnam-do, South Korea, approximately 70km apart from the Nakdong River mouth. The sea-level changes were reconstructed based on characteristics of shell middens and acorn hollows, sedimentary facies, AMS dating, and diatom analysis. The shell middens and acorn hollows were constructed during the early Neolithic Age and provide information on the paleo-sea level, because of influences of marine processes. The sedimentary facies are classified into a bedrock, base gravel and Holocene sediment (marine, terrestrial and back marsh sediments), upward. The sea level fluctuated during the middle Holocene is in harmony with those in Sejuk-ri, Ulsan and Pyeongtaek. In particular, the sea level at Bibong-ri of study area was higher than the mean high tidal level in Gimhae by approximately 1m during 5,000yr BP and maintained the stable condition during 4,000yr BP.

• Geophysics and Geophysical Exploration
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• v.2 no.3
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• pp.149-153
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• 1999

The study was performed as a part of 3-D exploration project of the South Con Son basin, where Korea National Oil Co. (KNOC) and SHELL Company are performing joint operation. In the structurally complex area, seismic facies or lap-out patterns, which are usually the tools for the conventional seismic stratigraphy developed by Exxon Group (Vail et at., 1977), are not easily identifiable. Therefore, stratigraphic informations are mainly extracted from seismic attribute maps of each sequence or systems tracts, and isopach maps in correlation with the stratigraphic information from the wells. The attribute maps of the sequence or systems tract boundaries and isopach map describe the variations of paleodepositional environments. The shape of the attribute maps of the boundaries is a reasonable description of the shape of the paleodepositional surface. With other maps such as isopach and structural maps, the variations of the parasequences in the systems tracts can be projected using the surface attribute maps. The reflection intensity attribute at each sequence or system tract boundary can be related to lithology, facies or porosity distributions. The azimuth attribute of source rock sequence can be used to identify the hydrocarbon migration patterns into the prospects. The overall risks of reservoir rocks, cap rocks, structure and hydrocarbon migrations were computed using the results of the study.