• Title/Summary/Keyword: Postglacial

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Bangudae-rockgraving-picture and environmental change in the Ulsan-Bay on the period of late-Postglatcial (반구대 암각화와 후빙기 후기 울산만의 환경변화)

  • 윤순옥
    • The Korean Journal of Quaternary Research
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    • v.9 no.1
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    • pp.1-18
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    • 1995
  • The intent of this study is to suppose the time of engraving of Bangudae-rockgraving-picture and the change of the ancient soci-ety related to the Postglacial transgression and regression in the Ulsan Bay. Main results can be summed up as follows; 1. It is supposed that the shoreline in the maximum Postglacial transgression of the Ulsan bay has arrived to Gulhwa-Ri about 14km upstream from the present Taehwa River mouth. 2,.This transgression has occurred about 6,000-5,000 years ago. The prehistoric men around the Bangudae had hunted the whale near the inner bay From this time the people had begun to engrave pictures on the Rock of Bangudae for the ceremony and instruction of the whale hunting,. 3. Since then the shoreline had regressed and the whale hunting area had moved to distant area from the residence and the number of the captured whales had diminished. The whale hunting society had been transformed to the overland animals on the Bangudae-rockgraving- pictures had gradually increased.

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The Geomorphic Changes of Sand-Beach Coasts by Human Impact in Byeonsan Peninsula, Southwest Korea (인간간섭에 따른 변산반도 사빈해안의 지형변화)

  • CHOI, Hoon;LEE, Min-Boo
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.3
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    • pp.83-96
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    • 2012
  • The origins of beaches at Byeonsan Peninsular, as a pocket type, are classified to a sand barrier type and wave-cut type. The beaches had developed by the deposition of the silt and clay layers on the 10m height from sea level in the inner bay during climax era of postglacial transgression. At that time, some sands had blown toward the inland hills to form aeolian deposits. After postglacial sea-level stabilization, sometimes, there has been the negative budget of beach materials. Recently, beaches have been transformed by human impact such as construction of Saemangeum sea-wall, especially in the Byeonsan and Gosapo beaches being close to the sea-wall. So the speed of tidal currents become slower and comparatively depositoinal activity stronger. And the level of chemical weathering has been higher. In Byeonsan beach, the ratio of coarse sand decreased with higher ratio of finer materials and by beach erosion dissected runnels developed, running parallel to the coastline. In Gosapo beach, supply of suspended materials are increased through the Garyeok drainage gate, the sands tend to be finer.

A Pollen Analysis on the Environmental Changes during the Later Half of the Postglacial Age around the Basin of Onyang River, Asan (화분분석을 이용한 아산시 온양천 유역의 후빙기 후기 환경변화)

  • PARK, Ji-Hoon
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.1
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    • pp.39-48
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    • 2010
  • This is a case study to research the environmental changes that occurred during the Latter Half of the postglacial age around the Basin of Onyang River in Asan, Korea. In line with this purpose, the author performed a pollen analysis and a radiocarbon dating on the deposits of alluvial fan around the upper Geumgok River, a tributary of Onyang River. Sampling point was at the altitude of about 67.5 meters, which belongs to the central zone of the cool temperate forest. The followings are the results of the study. The study area has passed through SC-I (the coniferous forest period in which Pinus was dominant), SC-II (the deciduous broad-leaved forest period in which Quercus and Castanea were dominant) and SC-III (the mixed conifer and deciduous broad-leaved forest period, in which Pinus, Quercus and Ulmus/Zelkova were dominant) respectively since about 3,000 yrB.P. SC-I period and SC-II period are presumed to be between about 3,000 and 2,000 yrB. P., and SC-III period to begin after 2,000 yrB.P. In comparison with the nationwide pollen zone during the postglacial age, SC-I and SC-II periods are contrasted with the R-IIIa zone and also the SC-III zone with the RIIIb zone. In addition, it is assumed that Pinus densiflora forest luxuriated there since 2,000 yrB.P. due to the destruction of forests, and that a lot of Fagopyrum pollen appeared; altogether, it was the so-called human interference period, from which forests began to be markedly destroyed. It is concluded that in those days inhabitants leaded agricultural life.

Postglacial Vegetation History of the Central Western Region of the Korean Peninsula (한반도 중서부 지역의 후빙기 식생 변천사)

  • Jang, Byeong-O;Yang, Dong-Yoon;Kim, Ju-Yong;Choi, Kee-Ryong
    • Journal of Ecology and Environment
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    • v.29 no.6
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    • pp.573-580
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    • 2006
  • A sediment core from the Cheollipo arboretum ($36^{\circ}$ 47' 57'N, $126^{\circ}$ 09' 04') was studied for pollen analysis in order to reconstruct postglacial vegetational change and environmental changes around the central western region of the Korean Peninsula. The record shows four pollen assemblage zones: Zone CHL-I, Quercus stage (ca. 9,300$\sim$6,200 yr BP): zone CHL-II, Quercus-Pinus stage (ca. 6,200$\sim$4,600 yr BP); zone CHL- III, Pinus-Quercus stage (ca. 4,600$\sim$1,160 yr BP): zone CHL-IV and Pinus stage (ca. 1,160 yr BP-present). During the 9,300$\sim$8,500 yr BP, the early Holocene, researchers have guessed a piece of cool-temperate norihern/altimontane mixed coniferous and deciduous broad-leaved forest. Between 8,500$\sim$4,600 yr BP the Quercus dominated the landscape of study area and the established dates of this typical cool-temperate central/montane deciduous broad-leaved forest vegetation might be ca. 6500 yr BP, and then the Pinus developed around the site at ca. 5,700 yr BP. The abrupt increase of Pinus and NAP (non-arboreal pollen) after ca. 1,100 yr BP indicates the vegetation changes due to human activities. From the dynamics of the Chenopodiaceae pollen indicating salt marsh and freshwater pollen flora such as Typha, Trapa, Nymphoides and so forth, we suggest that the tidal flat was altered into freshwater lake around 6,500 yr BP.

The Paleoenvironment of the Northern Part of the Nagdong River Delta (낙동강 삼각주 북부의 고환경)

  • 오건환
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.33-42
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    • 1994
  • The study area is filled up by alluvium which can be classified into lower and upper beds by the facies of deposits and their degree of weathering. The lower bed is not of marine but of fluvial. The upper bed is mainly composed of clay and silt or fine sand beds col-ored dark or dark gray which are of neritic or brackish yielding mollusca fossils. The oyster(Crassostrea ariakensis) obstained from the depth of 3m below the present sea level in the upper bed was dated at 4,100 110Y.B.P. and the veneridae(Meretrix lamarck) 1m height above the present delta plain in the old sand bar was dated at 1,700 85Y,B,P. It is therfore concluded that the study area a small kern col of terrestri-al basin prior to postglacial age had experienced the Holocene transgression. Consequently the study area is considered to have been progressively formed under neritic or brackish circumstance before 1,700Y.B.P.

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The Vegetational History of korea During the Holocene Period (홀로세 중 한국의 식생사)

  • 강우석
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.9-22
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    • 1994
  • The vegetational and environmental history of Korea during the Holocene period has reconstructed by the use of folral, palaeoclimatogical, archaeological data and written records. From 10,000 to 6,700 yeat B.P. in mid-eastern Korea, deciduous broadieaved trees gradually increased trees, notably at c.8,000 years B.P. From 6,700 to 4,500 years B.P., the vegetation remained dominated by Quercus and pinus(Diploxylon). Vegetational informations suggest the postglacial hypsithermal from c.8,000 to 4,500 years b.p. After 4,500 until 1,400 years B.P., the admixture of cryophilous trees in midland and thermophilous trees in south seems to imply the latitudinal divisions of vegetation and climate. The presence of cultivated rice pollen as well as non-arboreal pollen and spores indicates an increased rate of deforestation. From 1,400 years B.P., there was a sharp decrease in the representation of temperate trees, but the presence of the cryophilous genera Abies and pinus (Haploxylon) is noticea-ble and might be related to the occurrence of Little Ice Age. Fossil pollen diagram from western Korea and eastern Korea since 6,250 and 10,000 yeats B.P., respectively have enabled to compare vegetational dis-tribution patterns and changes in the Holocene period. In western Korea, Alnus- dominated vegetation continued from 6,250 to 1,500 years B.P., but pinus took over Alnus from 1,500 years B.P. In eastern Korea, however, Quercus and pinus dominated from 10,000 to 2,000 years B.P., but pinus be-came predominant from 2,000 years B.P. On a time- spatial basis, different vegetational distribution pattern can be recognised between western and east-ern Korea. The use of seven historical records which is unique to Korea also enabled to reconstruct the distributional pattern and temporal change of vegetation from 1425 to 1928.

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Vegetation History since the Mid-Lateglacial from Yeongsan River Basin, Southwestern Korea (영산강 유역 범람원 퇴적물의 화분분석 연구)

  • Choi, Kee-Ryong;Kim, Ki-Heon;Kim, Jong-Won;Kim, Jong-Chan;Lee, Gi-Kil;Yang, Dong-Yoon;Nahm, Wook-Hyun
    • The Korean Journal of Ecology
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    • v.28 no.1
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    • pp.37-43
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    • 2005
  • This study presents the Mid-Lateglacial vegetation history of southwestern Korea. From the result of AMS dating and pollen analysis, four local pollen assemblage zones(BS) were recognized. The four local pollen assemblage zones are BS 1. 12,222cal BC$\sim$9,160cal BC: cool-temperate northern/altimontane mixed coniferous & deciduous broad-leaved forest, BS 2. 9,160cal BC$\sim$ 4,210cal BC: cool-temperate central/montane deciduous broad-leaved forest, BS 3. 4,210cal BC$\sim$125cal BC: cool-Temperate southern/submontane mixed coniferous & deciduous broad-leaved forest. BS 4. BC125cal ${\sim}$present: warm-temperate/cool-temperate southern/submontane coniferous forest. Pine forest expanded since 4,210cal BC and full-scale rice cultivation might started since 2,120cal BC. A radical expansion of Pinus densiflora forest after postglacial stage might be caused by human impacts including full-scale agriculture.

A Marine Terrace Correlated to MIS 5e on the Basis of Pollen Analysis at Sanha-Dong, Ulsan, Southeastern Coast of the Korean Peninsula (화분분석에 의한 한국 남동부 해안 산하동 일대의 MIS 5e 대비 해성단구 동정)

  • Choi, Seong Gil;Shin, Hyeoncho;Park, Ji Hoon
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.3
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    • pp.1-11
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    • 2017
  • The pollen analysis on the deposits of the lower marine terrace I of the estimated paleoshoreline height of 18m was performed in order to estimate the formation age of this terrace developed at the Sanha-dong coast, Ulsan, southeastern coast of the Korean peninsula. The pollen assemblage of the peat layer of SH-1 pollen zone (Quercus-Ulmus/Zelkova zone), lying directly on the marine rounded pebble layer of this terrace, shows that the climatic environment of the deposition period of SH-1 pollen zone was almost similar to that of the Postglacial climatic optimum period, but slightly cooler than that of the late warm stage of Last Interglacial(MIS 5a) in the eastern coast of Korea. This heightens the possibility that the deposition period of the marine rounded pebble layer which was covered by the above SH-1 peat layer is the MIS 5e which has been estimated by a previous study of the sedimentary facies of this terrace deposits (Choi, 2016). The pollen assemblage of SH-2 pollen zone (Pinus-Quercus zone) shows that the climate of this period was almost similar to that of the late Postglacial, but slightly cooler than that of the period of SH-1 pollen zone. This means that the climate around the Sanha-dong was still warmer in the deposition period of the peat layer of SH-2 pollen zone. Thus, the peat layer of SH-2 pollen zone was considered to have been deposited during the period from the early regression stage of the MIS 5d which is the estimated final stage in the deposition period of the above peat layer of SH-1 pollen zone to any stage in which the warmer environment of MIS 5 has still lasted. The humic silt layer of SH-3 pollen zone (Pinus-Ulmus/Zelkova-Abies zone) is assumed to have been deposited during the interstadial of the Last Glacial (MIS 3).

Pollen Analysis on Tangjeong Plains, Asan-Si, Korea (아산(牙山) 탕정평야(湯井平野)의 화분분석(花粉分析))

  • PARK, Ji-Hoon;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.2
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    • pp.53-61
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    • 2010
  • In this study, pollen analysis and a dating were performed on the alluvial deposits in the Tangjeong Plains in Asan-Si, Chungcheongnam-Do. Specimens were collected at the altitude of about 12m, which belongs to the mid-forest belt in the cool temperate zone. The followings show the results. In general, the target zone passed through TJ-I (the coniferous forest age in which the Pinus forest was dominant), TJ-II (the mixed conifer and deciduous broad-leaved forest age in which Pinus and Quercus were dominant) and TJ-III (the coniferous forest age in which the Pinus was dominant) respectively. TJ-II was subdivided into TJ-IIa and TJ-IIb. TJ-I is presumed to be between about 2,810 and 1,500yrB.P.; TJ-IIa to be between about 1,500 and 1,370yrB.P.; and TJ-IIb to be between about 1,370 and 770yrB.P. As for TJ-III, it is presumed to begin after about 770yrB.P. In comparison with the nationwide pollen zone during the Postglacial, TJ-I and TJ-II are contrasted with the R-IIIa period and also TJ-III is contrasted with RIIIb (so-called human interference age). It is also presumed that Pinus luxuriated there after about 770yrB.P. as forests began to be markedly destroyed in the Tangjeong Plains.

Holocene Variations of Organic Carbon Contents in Lake Langer of King George Island, South Shetland Islands, West Antarctica

  • Khim, Boo-Keun;Yoon, Ho-Il;Kang, Cheon-Yun;Zhao, Junlin
    • Ocean and Polar Research
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    • v.26 no.3
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    • pp.507-514
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    • 2004
  • A sediment core drilled from Lake langer on King George Island was analyzed for a variety of textural md geochemical properties along with $^{14}C$ age dates. These data were combined with published records of other cores to provide a detailed history of Holocene variation of total organic carbon (TOC) contents with respect to terrestrial paleoclimate change. The lithologic contrast of the lower diamicton and upper fine-grained sediments shows the glacier activity and subsequent lake formation. Low TOC contents fluctuated during the diamicton deposition whereas the increase of TOC began with the lake formation during the postglacial period that started about 5,000 yr B.p More notable are the distinct TOC peaks that may imply enhanced primary productivity during the warm period. The uniform and low TOC contents may reflect the limited productivity during the evolution of the lake. However, the recent TOC readvance clearly indicates gradual warming on King George Island. However, the paleoclimatic signature in the terrestrial lake environment during the Holocene seems to be subtle and less distinct, compared to the marine environment.