• 한국지구물리탐사학회:학술대회논문집
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• 2009.05a
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• pp.27-34
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• 2009

Since the late 1980s, the sequence stratigraphic method has become a critical tool for hydrocarbon exploration/development projects in many frontier and mature sedimentary basins. The successful application of this method with high resolution 3D seismic data and well data is particularly important in frontier and deepwater areas, where exploration risk and capital commitment are high. Many international major and national oil companies have been using sequence stratigraphic approach as one of the main interpretation tools for the evaluation of their high impact projects. Applied correctly, this integrated interpretation method is a powerful tool that can be used to unravel the complex stratigraphy of a given basin and to dramatically increase overall understanding of various depositional models for both siliciclastic and carbonate systems.

• 한국석유지질학회:학술대회논문집
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• spring
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• pp.25-35
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• 1997

The latest Pleistocene-Holocene deposits on the Korea Strait shelf form a high-frequency sequence which consists of three systems tracts: the lowstand, transgressive and highstand systems tract. The lowstand systems tract is distributed on the shelf margin and trough region, whereas the highstand systems tract is confined only to the inner shelf. Although the transgressive systems tract between the lowstand systems tract and the highstand systems tract was identified over a wide area of the shelf, it is either very thin (a few meters thick) or absent.

• Proceedings of the Korean Quaternary Association Conference
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• 2004.06a
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• pp.51-51
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• 2004

As an important contribution to the planed drilling (IODP) in the central part of the Arctic Ocean, we are currently working on a refined chronostratigraphy for Marine Isotope Stage (MIS) 16 to MIS 2 on the exciting material from ODP Site 910A (Leg 151) which has been recovered from the marginal Eastern Arctic Ocean (the Yermak Plateau - the Atlantic/Arctic Ocean Gateway). Several stratigraphic age fix-points support the interpretation of the stable oxygen. isotope record of planktonic foraminifer N, pachyderma sin. that is punctuated by several short-term meltwater events. We believe that our new record will serve as 'the important correlating tool for establishing a basic stratigraphy for the Quaternary Arctic Ocean as well as for generating high-resolution paleoenvironmental reconstructions in the central Arctic Ocean. Furthermore, our study will provide reference stratigraphic data sets for interpreting the micropaleontological, sedimentological and organic / inorganic - geochemical proxies of the new boreholes that will be drilled on the Lomonosov Ridge(Central Arctic Ocean) in the frame of the "Arctic Coring Expedition' (ACEX, IODP) in summer 2004.

• The Korean Journal of Quaternary Research
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• v.17 no.1
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• pp.7-16
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• 2003

A 31m-long sediment core (SSDP-102) was taken from the inner shelf (about 40m water-depth) off the northwestern coast of the Korea Strait. Detailed lithofacies and organic-geochemical analyses were performed to establish a high-resolution stratigraphy in the Korea Strait shelf and to reconstruct the paleoenvironmental changes associated with the Holocene marine transgression. The stratigraphic framework of the core was primarily established using 6 AMS $^{14}C$ ages. The sedimentary record of the core SSDP-102 allows for the reconstruction of the paleoenvironmental changes during the last 12.1 ka BP. According to the high-resolution seismic reflection profiles, lithofacies and organic-geochemical data, the core SSDP-102 can be divided into three units (III to I in ascending order) above the acoustic basement. The three units reflect distinct changes of depositional environments resulted from the post-glacial marine transgression. Therefore, it is suggested that three phases of sea-level change have occurred within the inner shelf of the Korea Strait following the Holocene marine transgression. (1) estuarine environments from ca. 12.1 to 6.2 ka BP; (2) near-shore environments with a period of decreased rising of sea level between 6.2 and 5.1 ka BP; (3) near-shore to modem marine environments after 5.1 ka BP. In particular, the present marine conditions influenced by the warm Tsushima Current have been gradually established after ca. 5.1 ka BP.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.370-378
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• 2003

Continuous seismic refraction, reflection and echo-sounder surveys conducted at Koyna Project site provided geotechnical information which helped in choosing the alignment for Head race tunnel and in designing and choosing the site for Lake Tap. Seismic refraction survey both on land and in shallow water determined depths to bedrock and helped in inferring the bedrock quality. Seismic reflection survey mapped the subsurface stratigraphy with high resolution. Reservoir-bed and bedrock contours drawn from the results of the survey helped in choosing the tunnel alignment and the lake tap position cost effectively. It was inferred from the results of the survey that the geology and the quality of rock do not change unexpectedly around the site for extension of Head race tunnel and the lake tapping. The bedrock levels evaluated by seismic survey agreed remarkably well with those inferred in boreholes having Rock Quality Designation 90 percent or more.

• Journal of the Korean Geophysical Society
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• v.5 no.4
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• pp.271-281
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• 2002

Interpretation of high-resolution seismic profiles collected from the inner shetf of the Korea Strait reveals that the shelf sequence in this area consists of three sedimentary units (I, II, and III in a descending order) formed after the last glacial maximum. Lower two units (II and III) represent the transgressive systems tract formed during the Holocene transgression, Unit III above the sequence boundary is interpreted to be the transgressive estuarine deposit, whereas Unit ll above the ravinement surface forms a thin transgressive sand which consists of the sediment produced through shoreface erosion and winnowing during the transgression. Unit I above the maximum flooding surface is the highstand systems tract consisting mainly of recent muds derived from the Nakdong River.

• Geophysics and Geophysical Exploration
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• v.8 no.4
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• pp.243-250
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• 2005

Analysis of high-resolution seismic profiles acquired from the inner shelf off the southern coast of Korea reveals that the inner shelf sequence can be divided into three stratigraphic units formed after the Last Glacial Maximum (LGM). Unit I is characterized by complex seismic facies including semi-transparent, stratified, and hummocky reflections on seismic records. It consists of sandy mud or muddy sand, deposited under estuarine environment during the post-glacial transgression. Unit II acoustically shows semi-transparent or hummocky reflections and consists of sand with gravels and shell debris, produced by shoreface erosion during the transgression. Unit III is characterized by transparent or semi-transparent seismic facies and consists of mud originated from the Nakdong and Seomjin rivers during recent highstand of sea level. Unit III is confined to the inner shelf with an extenal form of stratal wedge.

• Journal of the Korean earth science society
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• v.33 no.1
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• pp.1-10
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• 2012

Analysis on high-resolution seismic and core data reveals that the sedimentary strata in Gyeonggi Bay consists of four sedimentary units (Unit I-IV, from top to bottom) formed during the late Quaternary period. Unit I is interpreted as sediments of tidal flat and channel-fill deposits, formed during the Holocene transgression. Unit II is divided into shallow-marine facies unit in offshore area and channelized fluvial to estuarine facies unit in nearshore sand ridge and tidal flat. Unit III is considered as tidal flat deposits with the uppermost severely weathered and oxydized layers. This unit is composed of shallow marine sedimentary successions formed during the MIS-5 highstand. The lowermost Unit IV rests on Mesozoic basement rocks, considered as the shallow marine and shelf deposits formed before the MIS-5 lowstand.

• The Journal of Engineering Geology
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• v.24 no.1
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• pp.9-21
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• 2014

We examined high-resolution seismic data, side scan sonar data, surface sediments, and vibrocore samples from a sand ridge off the western part of Dukjuk-Do in Gyeonggi Bay, with the aim of interpretation of seismic stratigraphy and sedimentary environment. Based on the seismic data, the deposited sands are divided into three sedimentary units. 14C age data indicate that the top sequence (sequence I) formed at 5000-6000 yr BP, when a transgression resulted in strong shifting tides. Analyses of the vibrocore samples indicate that sequence II is a paleo-mudflat layer of intertidal sediments dominated by mud. Sequence III consists of terrestrial sediments that are presumed to have been deposited at the end of the Pleistocene, unconformably overlying the acoustic bedrock and Mesozoic granite. The side scan sonar data indicate that sand waves were formed on the seabed on top of the sand ridge. Generally, this is the direction of $N20^{\circ}E$, which coincides with the direction of tidal flow. Sand ripples occur away from the top of the sand ridge and are distributed homogeneously across a sandy slope. Vibrocore analyses indicate that the surface sediments and core sediments (samples VC-1, -2, and -3) are homogeneous, without any internal structures, and are characterized by a mixture of medium and fine sand (1-$2{\phi}$), respectively.

• 한국해양학회지
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• v.28 no.4
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• pp.313-322
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• 1993

The Western south Sea of Korea can be divided into 4 acoustic facies (AF I-AF IV) according to the variations of acoustic characters. Typical acoustic characters revealed in high-resolution seismic profiles (3.5kHz) are prolonged, internal reflected, non-penetrated, and transparent types. These acoustic types probably controlled by bottom condition and sediment properties such as composition and compaction of sediments. Acoustic facies I is characterized by prolonged type which is produced by absorbing of acoustic signals on the coarse sediments including gravels and shell fragments and irregular bedforms. Acoustic facies II is characterized by internal reflected type which is probably produced by differential sediments compaction. Acoustic facies III is characterized by non-penetrated type caused by scattering of acoustic signals on the well sorted fine ad very fine sand sediments. Acoustic facies IV is characterized by transparent type with non-internal reflector in limited thickness. Acoustic types in high-resolution profiles provide important information not only about the stratigraphy of sub bottom but also abut the sedimentary processes in shallow sea.