• The Korean Journal of Quaternary Research
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• v.20 no.1 s.26
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• pp.1-8
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• 2006

Many boring investigations were achieved in Youngjong-North tidal flat to construct the Incheon International Airport Expressway. Vertical sedimentary profile of this tidal flat has been studied by analyzing these boring data. The deposits of Youngjong-North tidal flat are about 30 meters thick, and the sedimentary layers consist of basal gravel, lower mud, middle silt, middle mud, and upper silt layers in ascending order. Semi-consolidated and oxidized belt with yellowish brown color, which appears above or within middle mud layer, exists in $-3{\sim}-5$ meters altitude. There are some stratigraphical problems to admit the top surface of this oxidized belt as the unconformity surface between Holocene and Pre-Holocene tidal flat deposit.

• Journal of The Geomorphological Association of Korea
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• v.24 no.3
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• pp.13-25
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• 2017

This study is quantitative reconstruction of palaeo sea level records around Sinduk-ri, Gochang-Gun. 7 cores were collected from GC14 to GC18 in order to examine the entire sedimentary facies and reconstruct the sea level records. The cores were analysed by AMS, sedimentary facies, diatom and WA-pls. As a result of the diatom analysis, diatom zone were classified as No diatom zone, B1 zone, M zone and B2 zone. The result of WA-pls was that the sea level was about 1.5m lower than the present level around 6,000 BP and about 1m lower during last 5,000 BP. Thereafter, sea level rose to the present during the Mc sub-diatom zone period. Moreover, during the Md sub-diatom zone period, sea level was about 0.5m higher than the present.

• Journal of The Geomorphological Association of Korea
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• v.24 no.2
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• pp.51-64
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• 2017

The paleo-environments including changes in vegetation, climate, and sea level since the middle Holocene(6,400(?)-1,800(?) yr BP) were reconstructed with the special reference to pollen analysis from two trench samples at Yulha-dong, Kimhae-si, southern Korea. The environmental characteristics by the pollen zonation wassummarized asfollows: Pollenzone I(6,400(?)~3,940(?) yr BP)showed the dominance of Quercus species with broad-leaved trees, it was warm condition. Pollenzone II(3,940(?)~2,300(?) yr BP) was characterized to the yellow soil indicating terrestrial environment. Moreover, it showed Alnus-NAP period related to the extension of agriculture and deforestation by the rapid decrease of Quercus and increase of Gramineae. Pollenzone III(2,300(?)~1,800(?) yr BP) showed human impact from the increase of NAP and Pinus. Plenty of Quercus with deciduous broad-leaved trees also suggested warmer condition than before.

• Journal of The Geomorphological Association of Korea
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• v.24 no.4
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• pp.13-25
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• 2017

To reconstruct the paleo-temperature quantitatively and to overcome limitation of traditional qualitative pollen analysis, this study was performed pollen analysis using the modern surface soil at Yulha-dong, Gimhae-si of southeastern part of Korean peninsula. Canonical Correspondence Analysis(CCA) was done to identify the most important environment variable about composition of modern surface pollen sample. Also, Weighted Average-Partial Least Square(WA-PLS) was analyzed to obtain modern surface pollen-temperature transfer function. The transfer function was applied to the results of qualitative fossil pollen analysis at Yulha-dong, Gimhae-si, Sampyung-ri, Ulsan-si and Taewha-dong, Ulsan-si. Therefore, the paleo-temperature was reconstructed during the Holocene since 6,200 yr BP. According to the results of the research, it is $1{\sim}2^{\circ}C$ lower than the current average annual temperature at the study area in 6,200 yr BP, since then it increased to the same level to the current temperature and decreased again until 2,600 yr BP. From the 2,600 yr BP, the temperature was fluctuated to the present.

• The Korean Journal of Quaternary Research
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• v.24 no.1
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• pp.25-33
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• 2010

Holocene vegetation and climate changes were assumed on the basis of pollen records from Wonpyeong Trench II-3 of the Osong archaeological site, Cheongju, Chungbuk Province, Korea. An organic matter beared in coarse sediments appeared to be low throughout the succession. Although an occurrence of pollen grains is not high, some dominant and principal taxa may indicate vegetation changes response to climate changes in central inland area of the Korean Peninsula. The age determination can be estimated with indirect way by comparing with previous age-controlled pollen studies. It is assumed that the former last glacial conifer forests had been changed into open mixed conifers and deciduous broadleaved forest during the early Holocene period. Warmer and more humid climate conditions, during the mid-Holocene, might have allowed the hardwoods including deciduous- and evergreen-broadleaved trees, and warm-preferring pine tree to flourish. Subsequently, the former forests were replaced by mixed of conifer and deciduous broadleaved forest owing to deterioration of climate conditions during the late Holocene. Human activity is also detected by agricultural indicators, such as buckwheat and large pollen grains comparable to corn, in upper most pollen profile. During this time, the forests in studied area were primarily affected by human disturbance rather than natural environment.

• Journal of the Korean Geographical Society
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• v.44 no.6
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• pp.691-705
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• 2009

Phytolith analysis was made on a 660cm core from Lake Gyeongpo in the East Sea of Korean Peninsula to clarify the environmental change including climate and agricultural characteristics during the Holocene. From the results of phytolith analysis, six phytoliths assemblage zone(PAZ) were recognized from the base to the surface. PAZ I around 5,000 yr BP suggests the transition from the warm and dry to the cool and wet climatic conditions. The climate of PAZ II(ca. 4,000-2,000 BP) was kept on warm, but repeated between dry and wet conditions. PAZ III(2,000~1,000 yr BP) suggests the expansion of agricultural activities under the warm and humid climatic conditions due to the significant phytoliths production of Paniceae and Oryza sativa. While PAZ IV(1,000~500 yr BP) indicates very cool and dry conditions, PAZ V and IV suggest the warm-dry and cool-humid climatic conditions, respectively. Similar to the results of pollen analysis in the lake, the agricultural activities were recognized by PAZ III around 2,000 yr BP from the results of phytolith analysis, and the rice cultivations such as Oryza sativa have been expanded since 2,000 yr BP or later.

• The Korean Journal of Quaternary Research
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• v.25 no.1
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• pp.15-30
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• 2011

Three sediment cores from two different locations (UJ-03 and UJ-12 cores of valley sediment in Paju area, and CL-4 core of wetland sediment in Cheollipo area) along the western Korean Peninsula yield crucial information on the timing and spatial pattern of century-scale climate changes and subsequent surficial responses during the Holocene. In Paju area, the sediments included abundant coarse-grained sediment (coarse sands and pebbles) from 7100 to 5000 cal. yrBP, total organic carbon (TOC) values showed a marked increase from 5000 to 2200 cal. yrBP, several intermittent depositional layers were observed from 2200 cal. yrBP. In Cheollipo area, lake environment developed from 7360 to 5000 cal. yrBP, the deposition of organic materials increased from 5000 to 2600 cal. yrBP, peatland formed from 2600 cal. yrBP. The two patterns of surficial responses to the climate changes through the Holocene are different to each other. This might be due to the dissimilarity in geomorphic conditions. However, the approximate simultaneity of environmental changes in two areas shows that they both can be correlated to the major climate changes. Two areas which have undergone significant changes indicated that the hydrological factors including precipitation and strength of water flow were most responsible for the landscape and geomorphic evolutions. Although the upwards trend in relative sea-level also played a primary role for environmental changes in coastal area (Cheollipo area), detailed studies have still to be undertaken.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.235-246
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• 2011

Sea level fluctuations during the Holocene reconstructed by the results of age dating, microfossils researches and sedimentary facies from coastal alluvial plains contain the valuable informations on climatic changes. The sea level during 'maximum phase of transgression' during 6,000~5,000 yr BP was slightly higher than the present by approximately 0.8~1.0 m and the summer temperature conditions seemed to be higher than those of the present by 2~3℃ in the Central Europe when the period of 'Climatic Optimum' might be dominant. The sea level in Korean Peninsula was assumed by 0.8~1.0 m higher at that time compared to the present and climate seemed to be warmer. At 2,000~1,800 yr BP in Korean Peninsula, the sea level reached the higher stand than the present by approximately 1.1~1.3 m and the climatic conditions might be warm similar to the period of 'Climatic Optimum'. Although the temperature in the Central Europe during the period of 'Subboreal' was about 2~3℃ cooler, it is supposed that the sea level in Korean Peninsula was relatively higher than the present. The sea level at 2,300 yr BP might be similar to that of the present, which was the lowest level since the mid-Holocene. From the fact, climatic environment during the cold period might not be reflected exactly in the sea level.

• KOMUNHWA
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• no.48
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• pp.101-113
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• 1996

• 한국해양학회지
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• v.30 no.4
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• pp.320-331
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• 1995

The closely spaced cores were analyzed to find detailed reconstruction of paleoenvironments and sealable changes along the Delaware Bay coast. Three areas, Kitts Hummock Beach mars, the St. Jones River marsh, and Bowers marsh near the St. Jones River's mouth, were chosen because these areas are compose of their own geomorphic characteristics and sea-level history. since significance of the stratigraphic correlations was to determine sedimentary fancies and paleoenvironments, multidisciplinary methods such as lithological description, grain-size analysis, organic/inorganic content, water content, mineral composition, botanical analysis, micropaleontological analysis, and /SUP 14/C datings were performed. Five major divisions of marsh environments were recognized in the stratigraphic sections: freshwater marsh, initialfreshwater marsh, slightly brackish marsh, brackish marsh, and salt marsh. Most of the lower part in the stratigraphic sections show freshwater marsh. On the top of this, either brackish marsh or tidal flat/tidal stream was recorded. The pro-Holocene sediments consist of sand, mud, and sandy mud, The pre-Holocene configuration played an important role for developing the Holocene Paleoenvironmental changes. The irregular configuration of the pre-Holocene sediments consist of sand, mud, and sandy mud. The pre-Holocene configuration played an important role for developing the Holocene Paleoenvironmental changes. The irregular configuration of the pre-Holocene surface within short distances permitted the concurrent development of variable environments such as freshwater marsh, brackish marsh or salt marsh at similar elevations. The freshwater marsh in this case was formed in the areas of isolation, so saline-water cannot encroach upon these areas. This complex development of paleoenvironments leads to a difficulty in stratigraphic correlation and interpretation of local relative sea-level changes. The deposition of subsurface sediments was affected by sediment supply, compaction, fluvial activity, biological competition, local tectonics and isostacy, climate and local relative sea-level changes. It was interpreted that the positions in the changes from freshwater environments to brackish environments or ice versa are the turning points of transgressions and regressions. Therefore, multiple transgressions and regressions were identified in the stratigraphic sections of the study area.