• Journal of the Korean earth science society
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• v.26 no.3
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• pp.276-282
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• 2005

The Quaternary palynoflora from Cheongsu core, drilled on the western part of the Jeju Island, consists mainly of deciduous broad-leaved angiosperms and herbs. Dominant taxa are Pinaceae, Alnus, Castanea/Castanopsis, Ulmus/Zelkova, Chenopodiaceae and Compositae. Based on palynofloral composition, two palynostratigraphic zones are recognized. Zone I is characterized by a predominance of Alnus and Chenopodiaceae, and by the abundance of herbs. Zone II is dominated by conifers and deciduous broad-leaved angiosperms, including Abies, Taxodiaceae-Cupressaceae-Taxaceae, Ulmus/Zelkova and Gramineae. The Cheongsu palynoflora can be correlated with Alnipollenites(Alnus)-Chenopodipollis(Chenopodiaceae)-Compositae Assemblage Zone of the East China Sea and is assigned to the Pleistocene in age. Ecology of main taxa and comparison with the present vegetation of Korea suggest a cool temperate climate and a low relief in the Jeju Island during the deposition of the Cheongsu core sediments.

• The Korean Journal of Zoology
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• v.34 no.4
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• pp.571-584
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• 1991

잉어과(Gyprinidae)의 Zocco속 어류 4종과 Candidia속 어류 1종에 대한 종간 유연관계와 종분화 연대측정 및 이들의 지질학적 분포경로를 밝히기 위하여 한국, 일본 및 대만에서 채집된 개체를 대상으로 전기영동법에 의한 유전자 분석을 하였다. 각 종의 지역별(한국, 일본, 대만) 집단간 유전적 유연관계를 분석한 결과 평균 유전적 근연치는 90% 이상이었다. Z. temmincki의 경우 일본집 단들은 한국의 A-type 집단과는 유연관계가 가까왔으나 한국의 B-type과는 유전적 차이가 현저하러다. Z. PlaD여5의 경우 한국집단과 일본집단사이의 유연관계는 S = 0.852였고, 한국집단과 대만집단 사이는 5 = 0.672, 일본집단과 대만집단 사이는 S = 0.751로서 지리적으로 현저한 차이를 업였다. Z. pochycephalus 3개 집단간의 유전적 근인치는 S = 0.963이었고 Candidia borbota 2개 집단간은 S = 0.946이었다. 종간의 유전적 근연환계를 비교한 결과 Candidia borbota와 Z. temmincki사이는 S = 0.608, Z. pluDpus와 1. pachycephalus사이는 S = 0.612였으나, Z. temmincki와 Z. platypus사이는 S = 0.441, Z. temmincki 와 Z. pochycepholus 사이는 S = 0.350이었고, Z. plotpus와 Condfda barbata사이는 S = 0.328로서 이들 사이에는 현저한 유전적 차이가 있었다. 각 종간의 롱분화 연대를 추산한 결과 이들은 약 480만년 전인 Pliocene 초기에 공통 조상종에서 분화하여 Z. temmincki, Candidia borbato group과 Z. plotypus, Z. pochycepholus group으로 분리되었고 약 260만년 전인 Pliocene 후기에 Z. temminc소와 Candidia borbota로 분화되었다고 추산되며 약 80만년 전인 Pleistocene시기에 남 temmincki B-type에서 h-type이 분화되었다짙 여겨진다. 한편 또 다른 한 단opP은 약 230만년 전인 열iocene후기에 대만 지역의 Z. plotypas에서 Z. pochvcepholus가 분화된 후 현재에 이르렀다고 추정된다. Z. platypus는 약150만년 이전인 초기 Pleistocene시기에 대만지역에서 한국 및 일본집단으로 분리되었다고 보며 이들 한국집단과 일본집단은 약 50만년 전 Pleistocene의 Middle기에 고황하 수계를 거쳐 현재의 분포 상황에 이르렀다고 여겨진다. 한편 대. temmin체과의 B-type에서 저온 적응으로 분화되었다고 추측되는 A-type은 약 20만년 전인 Pleistocene의 Riss기에 역시 고황하 수계를 통하여 한국과 일본으로 분포하여 현재에 이르렀다고 사료된다.

• The Korean Journal of Quaternary Research
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• v.13 no.1
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• pp.79-89
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• 1999

Three deep borings to obtain vertical continuous samples including weathered basement soils (KP-1, KP-2 and KP-3) were carried out in the reclaimed Kimpo tidal flat with purposes to establish late Quaternary stratigraphy. On the basis of detailed observations and descriptions on color, sedimentary structure and textural composition of cored sediments, four lithostratigraphic units are classified. From the stratigraphic top to bottom, they are Holocene tidal sand and muddy deposit (Unit I), early Holocene freshwater marsh muddy deposit (Unit II), late Pleistocene tidal sand and muddy deposit (Unit III) and late Pleistocene basal fluvial gravel deposit (Unit IV). In particular, Unit III is divided into two parts: the upper part-weathered and cryoturbated part during the Last Glacial Maximum (Unit III-a) and the lower part-unweathered tidal sand and muddy deposit (Unit III-b).

• Journal of the Korean Geographical Society
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• v.33 no.3
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• pp.447-454
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• 1998

As a widespread tephra erupted 24 to 25 KA, Aira-Tn Ash, or AT, provides an invaluable datum for stratigraphic study of late Pleistocene in Northeast Asia. AT can be identified from their tonal characteristic and morphology (the so­called bubble-wail feature), as well as typical refractive index. First reported in 1983, its presence was confirmed from many palaeolithic deposits distributed throughout Korea. It forces us to reconsider the age of prominent Pleistocene deposits. At the famous archaeological site of Chon-gok-ni, presence of AT lends a firm support that sedimentation and deposition of lithic assemblage were in fact a late Upper Pleistocene event, thus, throwing a new question at archaeologists to explain why such archaic-looking tools were continued to be made. Discovery of AT at Chongdongjin is more surprising, since the coastal terrace has been regarded by many as an early Lower Pleistocene eustatic feature. It implies strongly that we need to devise a new scheme for Quaternary stratigraphy. In the absence of reliable datum and marker for Quaternary research, efforts must be given to search for and identify AT and other widespread tephras.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.27-27
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• 2001

• Proceedings of the KSEEG Conference
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• 2000.04b
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• pp.282-282
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• 2000

• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.17-17
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• 2004

The Pleistocene lake level and climate development is described by proxies from sediment, pollen and diatom records in Mongolia and Northwest-China. It could be proved that higher lake levels seem to have existed during the old and mid Pleistocene period interpreted on the base of geomorphological and sedimentological reords. They are dated in a relativ time scale. The lake basins are filled up to 300 m by limnic deposits, which foused on a constant water balance of more than 700.000 years. Late Glacial and Holocene lake level fluctuations and climate changes can be proved by biostratigraphic records pointing to dry and wet phases. Only for the youngest history desiccation of some lakes are related to human impact.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.363-369
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• 1999

Reconstruction of the past vegetational changes of Korea in connection with climate changes enables to understand the impacts of past and future global warming on alpine vegetation. Despite the early appearance of the cold-tolerant vegetation since the Mesozoic Era. the occurrence of warmth-tolerant vegetation during the Oligocene and Miocene implies that most of alpine and subalpine vegetations have been confined to the alpine and subalpine belts of northern Korean Peninsula. The presence of cold-episodes during the Pleistocene. however. might have caused a general southward and downslope expansions of cold-tolerant alpine and subalpine vegetation. But the climatic warming trend during the Holocene or post-glacial period eventually has isolated cold-tolerant alpine and subalpine vegetation mainly in the northern Korea. but also on scattered high mountains in the southern Korea. The presence of numerous arctic-alpine and alpine plants on the alpine and subalpine belts is mainly due to their relative degree of sensitivity to high summer temperatures. Global warming would cause important changes in species composition and altitudinal distributional pattern. The altitudinal migration of temperate vegetation upward caused by climatic warming would eventually devastate alpine plants.

• 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.

• Journal of the korean society of oceanography
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• v.32 no.3
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• pp.138-144
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• 1997

The tidal deposits in the Haenam Bay, southwest coast of Korea, are stratigraphically divided at least into two units (Unit I of Holocene and Unit II of late Pleistocene) based on the obtained vibracoring sediments. In Unit I, clay minerals of illite, chlorite, kaolinite and smectite are observed as similar to those of the other modern tidal deposits. Of note, however, is the absence of smectite and chlorite in the upper part of Unit II compared with the clay mineral compositions of Unit I. It is concluded that the subaerial weathering and diagenetic effects rather than depositional processes are responsible for the positive and characteristic differences in clay mineral compositions between two units, that is, the upper part of Unit II was exposed subaerially and weathered diagenetically prior to the late Holocene transgression. Therefore, the bounding relationship between Unit I and Unit II is unconformable.