• Title/Summary/Keyword: radiocarbon dating

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A Preliminary Geomorphic Overview of Late Quaternary Glacier Fluctuations in the South Shetland Islands, West Antarctica (서남극 남쉐틀랜드 군도의 제4기 후기 빙하 활동의 지형학적 고찰)

  • Lim, Hyoun-Soo;Yoon, Ho-Il;Lee, Yong-Il;Kim, Yea-Dong;Owen Lewis A.;Seong, Yeong-Bae
    • Journal of the Korean Geographical Society
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    • v.41 no.5 s.116
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    • pp.513-526
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    • 2006
  • The timing and extent of glaciations during the Late Quaternary in the South Shetland Islands, West Antarctica were defined using field mapping, geomorphic analysis and radiocarbon dating. Landforms of glacial erosion and deposition, in particular subglacial meltwater channel erosion, suggest that at least three glaciations occurred during the late Quaternary within the study region. During the global LGM, glacial troughs (such as Maxwell Bay and Admiralty Bay) were overdeepened by an ice stream moving south from $an\sim1000m-thick$ ice cap centered on the present-day continental shelf to the north. This ice was responsible for the subglacial meltwater channel erosion, and glacial polished and striated bedrock on the Fildes Peninsula. The recent local glaciations occurred about 2,000 years ago and during Little Ice Age (LIA). During these glaciations, glaciers were less extensive than the previous one and less erosive as a cold-based ice

Lacquer Layers and Making Methods of the Wooden Coffin Excavated from the Nongso Tomb of Unrimri, Sunchang in Korea (순창 운림리 농소고분 출토 목관 칠 분석을 통한 제작방법 연구)

  • Lee, Hye Youn
    • Journal of Conservation Science
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    • v.33 no.5
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    • pp.355-362
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    • 2017
  • The Nongso tomb of Sunchang was built in a relatively deep place; hence there was little damage from grave robbers. The tomb was completely filled with a large amount of charcoal, and therefore the wooden coffin was excavated in relatively good condition. On the basis of the structure of the tombs, excavated artifacts, and radiocarbon dating results, the tomb is estimated to be from between the late Goryeo and the early Joseon period. The wooden coffin excavated is double-layered structures consisting of an outer coffin and an inner coffin. The outside of the wooden coffin is thickly lacquered and decorated with yellow letters and white motifs. An analysis of the pigments' components revealed that the major component of the letters was gold (Au) and the major component of the motifs was silver (Ag). The coffin lacquer had three layers: a pigment layer, a yellowish-brown layer, and a black layer. The wooden bases of the coffins were painted with a black substance, such as soot, as mineral elements were not detected in the black layer. The yellowish-brown layer is presumed to be refined lacquer. From the analysis of the structure of the layers and pigments, we can estimate the method was adopted for making lacquer for wooden coffin. It is assumed that the method used gold leaf and gold powder. The form of the pigment and the internal structure are likely to be gold leaf, but the shape of the surface letters appears to have been formed using gold powder. This study will serve as important information for understanding lacquer making techniques at the time of the tombs' construction by confirming the making method through reproduction experiments using gold leaf and gold powder.

Scientific Analysis and Conservation of Waterlogged Woods Excavated from Suyoeng-ri Site, Hwaseong, Korea (화성 수영리 유적 출토 수침목제유물의 과학적 분석 및 보존처리)

  • Lee, Kwang-Hee;Oh, Jeong-Eun;Kim, Soo-Chul
    • Journal of Conservation Science
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    • v.37 no.5
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    • pp.579-589
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    • 2021
  • Five waterlogged wood artefacts were excavated from Suyeong-ri site in Hwaseong, South Korea. The aim of the present study was to identify the species and estimate the date of manufacture and the manufacturing method of these artefacts. The study also aimed to conserve the original shapes of waterlogged wood artefacts by using the vacuum freeze drying method. The two large waterlogged woods were identified as Ulmus spp. and Morus spp., whereas one of the three small waterlogged woods was identified as Abies spp. and the other two as hard pine. Radiocarbon dating using wiggle match dated the manufacturing of these wooden artefacts between BCE 8520-8490 or BCE 8470-8290 in the Neolithic age, and a similar period was also confirmed for seed excavated from a place close to the location where the waterlogged wood artefacts were excavated. The surface of waterlogged wood artefacts had several traces of manufacturing processes - traces of tearing and chopping - were observed. Based on these observations, it was confirmed that stone adz was used to make these wooden artefacts. Thereafter, the waterlogged wood samples were conserved by immersing them into PEG#4,000 of concentration in water from 10% to 40% at room temperature(15~25℃) and subjecting them to vacuum freeze drying. However, the internal moisture was not completely removed in some thick parts of waterlogged woods by applying the general schedule such as raising the shelf temperature as the surface temperature rises. Therefore, additional study is required using the schedule-method for vacuum freeze drying of large waterlogged wood.

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.

The Process of Hillslope Denudation and History of Mass-Movement at the Uppermost Stream of Maegokcheon During the Holocene (충남 매곡천 최상류에 있어서 홀로세 구릉사면의 삭박과정과 사면물질이동의 이력)

  • Park, Ji-Hoon;Jung, Hea-kyung
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.2
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    • pp.25-37
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    • 2011
  • The purpose of this study is to investigate the history of phenomenon(hereinafter called mass-movement) of movement of inorganic material originated from hillslope by denudation of hillslope surrounding the watershed during Holocen period in the Chaamgol watershed(hereinafter called study watershed) uppermost stream of Maegokcheon Cheonan-si Chungnam. To do this, for the object of allivium distributed in valley bottom of study watershed, facies analysis, radiocarbon dating and grain size analysis were conducted and geomorphological analysis on study watershed conducted together. The result is like the following. It was confirmed that over around 9,100yrBP~to recent due to a few times of mass-movement occurred in time scale of 102~103 years, a large quantity of inorganic material is mixed in organic material layer originated from wetland formed in valley bottom of study watershed or exists between organic material layers. And it was found that in study watershed, mass-movement occurred in instable period of hillslope after the Early Holocen existed at least 8 times (M1 period~M8 period) and wetland environment formed in the stable period of hill slope existed total 4 times (W1 period~W4 period). This analysis result will be used in the future as basic material in research of Holocen climate change of Maegokcheon watershed and in restoration of denudation process of hillslope following this.

Scientific Analysis and Conservation Treatment on the Buddhist Scriptures of Paper Relics Excavated from Sum Tolgoi, Mongolia (몽골 숨 톨고이 출토 지류 유물의 과학적 분석 및 보존처리)

  • Bae, Su Bin;Yang, Min Jeong;Kwon, Yun Mi;Yoo, Ji Hyun;Jeong, Hee Won
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.723-737
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    • 2021
  • This study analyzed the composition and structure of materials with Buddhist paper scriptures excavated from architectural sites in 'Sum Tolgoi' of the 17th century and carried out conservation treatment base on the result of the analysis. The scriptures were covered in dust and foreign sub stances, and were so crumpled that it was impossible to identify the form. The damage, loss, and discoloration have been identified. Buddhist scriptures written in Tibetan used indigo and ink sticks on paper as a result of UV-Vis analysis, and ink sticks as black character materials from scriptures written ancient Mongolian. SEM-EDS and Micro-XRF analyses revealed that the outlines were drawn with red lines using a mix of Minium (Pb3O4) and Cinnabar (HgS), or Cinnabar (HgS) alone, and the contents of the scriptures were written with silver paint. Silver chloride (AgCl) and Calcium (Ca) were identified in the silver paint component of the characters, while Calcium and Orpiment (As2S3) were identified in the yellow lines. Concerning the paper ground, Buddhist scriptures written in ancient Mongolian were characterized by herbal plant fiber and bast fiber, and those written in Tibetan, by bast fiber. Radiocarbon dating indicates that the paper for the scriptures was produced between the 15th and 17th centuries. Conservation treatment of the scriptures was carried out based on the experiment on the production of pre-coated paper and how to coat that to prevent the second damage due to the deformation and fragility of the excavated paper. The scriptures were preserved and mounted, and a neutral box was made to identify the contents of the scriptures recorded on both sides after the treatment. This conservation treatment is the result of a study that applied new conservation treatment materials and methods according to the principle of conservation treatment reversibility.

Benthic Foraminiferal Assemblage and Sedimentary Environment of Core Sediments from the Northern Shelf of the East China Sea (북동중국해 대륙붕 코아 퇴적물의 저서유공충 군집 특성과 퇴적환경 연구)

  • Kang, So-Ra;Lim, Dhong-Il;Kim, So-Young;Rho, Kyoung-Chan;Yoo, Hae-Soo;Jung, Hoi-Soo
    • Journal of the Korean earth science society
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    • v.29 no.6
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    • pp.454-465
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    • 2008
  • Benthic foraminiferal assemblage and AMS radiocarbon dating of core sediments from the northern shelf of the East China Sea were analyzed in order to understand the paleoenvironment and sedimentary environmental changes around the Korean marginal seas since the last glacial maximum (LGM). The core sediments, containing continuous records of the last 16,000 years, reveal a series of well-defined vertical changes in number of species (S), P/T ratio and species diversity (H) as well as foraminiferal assemblage. Such down-core variations display a sharp change at a core depth of approximately 240 cm, which corresponds to ca. 10,000 year B.P. The sediments of the lower part of the core (240${\sim}$560 cm, Zone I), including the well-developed tide-influenced sedimentary structures, are characterized by high abundances of Ammonia beccarii and Elphidium clavatum (s.l.) and low values in number of species, P/T ratio and diversity. These tide-influenced signatures and foraminiferal assemblage characters suggest that the sediments of Zone I were deposited in a coastal environment (water depths of 20${\sim}$30 m) such as tidal estuary with an influence of the paleo-rivers (e.g., old-Huanghe and Yangtze rivers) during the early phase of the sea-level rise (ca. 16,000 to 10,000 years) since the LGM. In contrast, the upper core sediments (0${\sim}$240 cm, Zone II) are characterized by abundant Eilohedra nipponica and Bolivina robusta with a minor contribution of A. ketienziensis angulata and B. marginata. and high values in number of species, P/T ratio and diversity. Based on relative abundance of these assemblage, Zone II can be divided into two subzones (IIa and IIb). Zone IIa is interpreted to be deposited under the inner-to-middle shelf environment during the marine transgression in the early Holocene (after ca. 9,000 yr B.P.) when sea level rapidly increased. The sediments of zone IIb most likely deposited after 6,000 yr B.P. under the outer shelf environment (80${\sim}$100 m water depth), which is similar to modem depositional environments. The muddy sediments of zone IIb were probably transported from the old-Huanghe and Yangtze Rivers during the late Holocene. We suggest that the present-day oceanographic conditions over the Yellow and the East China Seas have been established after ca. 7,000${\sim}$6,000 yr B.P. when the Kuroshio Current began to influence this area.

Diatom Assemblages and its Paleoceanography of the Holocene Glaciomarine Sediments from the Western Antarctic Peninsula shelf, Antarctica (남극반도 서 대륙붕의 빙해양 퇴적물의 규조군집 특성과 고해양 변화)

  • Shin, Yu-Na;Kim, Yea-Dong;Kang, Cheon-Yoon;Yoon, Ho-Il
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.6 no.3
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    • pp.152-163
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    • 2001
  • Based upon the sedimentological, geochemical and micropaleontological analyses of two sediment cores from the Antarctic Peninsula (AP), three distinct lithological units can be recognized: (1) ice-proximal an/or ice-distal diamictons in the lower part of the cores, accumulated just seaward of the grounding line of the ice shlef until 11,000 yrs BP; (2) diatomaceous mud between 6,000 and 2,500 yrs BP in the middle part, resulted from a large influx of organic materials by enhanced production of open marine condition; (3) diatomaceous sandy mud since 2,500 yrs BP, characterized by an increase in sand content and decrease in TOC and diatom abundance in the lower layers, which reflects the formation of more extensive and seasonally persistent sea ice. Based on the C-14 radiocarbon dating, the sub-ice shlef deposition of the diamicton on the AP western shelf completed around 11,000 yrs BP. Colder condition was reinstated between 12,800 and 11,600 BP with a dropin TOC content and diatom abundance, which is coincident with the Younger Dryas event in the North Atlanticregion. At this time, the ice shelf, that is now absent in the study area, appears to advance as evidenced by an abrupt increase in sea-ice taxa. A climatic optimum is recognized between 9,000 and 2,500 BP, coincide witha mid-Holocene climatic optimum 'Hypsithermal Warm Period' from the other Antarctic sites. During this time, diatomaceous mud accumulated by a large influx of organic materials by enhanced production occurred in openmarine condition. Around 2,500 BP, diatomaceous sandy mud reflects the formation of more extensive and seasonally persistent sea ice, coincident with the onset of the Neoglacial in the Antarctic. Our results provide evidence of climatic change from the Antarctic Peninsula`s western shelf that helps in determining the existence and timing of Holocene milennial-scale climatic events in the Southern Hemisphere.

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A Preliminary research on Sixth-century Wooden Buddha Images from Funan (6세기 푸난 목조불상에 대한 시론(試論))

  • Noh, Namhee
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.99
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    • pp.10-29
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    • 2021
  • This paper is an introductory study of the wooden Buddha images excavated in the Mekong Delta in present-day southern Vietnam. Approximately thirty examples of wooden Buddha images have been recovered in the Mekong Delta. As they were found among the major historic sites of Funan (the first kingdom in Southeast Asia), including Oc Eo, and likely date to the sixth century, they can be regarded as the works of Funan. Similarly to stone Buddha images, these wooden examples are considered important for their demonstration of aspects of early Buddhist sculpture in Southeast Asia. Most of these Funan wooden Buddha images are presumed to have been produced around the sixth century based on radiocarbon dating and their stylistic characteristics. This paper analyzed the iconography and style of eight examples whose forms are relatively recognizable. The eight images can be divided into four types according to their postures, dress styles, and hand gestures. They all share features of the Sarnath style of the Gupta period in India as seen in their slender bodies and the outer robe that clings to the body. However, some display a South Indian style of Buddha images in their upright posture, style of wearing a monastic robe with the right shoulder exposed, and making the vitarka mudra (preaching gesture) that is often seen in Sri Lankan Buddha images. This suggests that Buddhist sculptors in Funan devised a new style by incorporating the principal styles of Indian Buddhist sculpture. Another notable feature of these Funan images is their material, namely, wood. While none of the contemporaneous Hindu sculptures discovered from the same historic sites are made of wood, numerous Buddhist sculptures are. This paper postulates that the use of wood in Buddhist sculptures was promoted for reasons beyond ease of carving. According to the Buddhist literature, the first-ever Buddha image was the so-called 'Udayana image' made out of sandalwood. This image and its story was well-known in the Southern Dynasty of China around the sixth century. Interestingly, some auspicious sandalwood images of the Buddha was believed to have been brought into the Southern Dynasty from Funan. This suggests the possibility that the legend of the Udayana image might have been known in Funan as well and resulted in the production of wooden sculptures there.

Temporal-Spatial Location of Dwelling Site in Asan Bay in the Neolithic Age (아산만지역(牙山灣地域) 신석기시대(新石器時代) 집자리의 시공적(時空的) 위치(位置))

  • Koo, Ja Jin
    • Korean Journal of Heritage: History & Science
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    • v.42 no.3
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    • pp.26-47
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    • 2009
  • This study examined dwelling site from among the sites of the Neolithic age found in the Asan Bay(牙山灣) area, and the temporal-spatial location and meaning of the dwelling site (settlement). The majority of the settlements in the area are of a square style but some coexist with rectangular-style settlements, which is noteworthy. The dwelling sites of the Neolithic age found in Asan Bay area are mostly located in a ridge of hilly areas, divided into gentle, low areas (20~50 meters above sea level) and relatively high areas (50~80 meters above the sea level). Although location strongly corresponded to the residents' subsistence and the technical levels within the culture, it likely was greatly affected by natural environment where they lived, as well. In examining radiocarbon dating results and the excavated artifacts, the settlements found in Asan Bay were determined to belong to the period II(3,500~3,000 B.C.) stated in the Relative Chronological table of Dwelling sites in the Neolithic age, written by the author. Said Dwelling sites are proven to have a close relationship with those found on the coast of Gyeonggi Province(京畿道) and in the Geum River(錦江) valley. This is deemed to be the result of expansion and interchange between Gyeonggi Province(京畿道) group and Geum River(錦江) valley group, who constituted the large settlements. Additionally, the Daecheon-ri type dwelling sites in the Geum River valley were verified to be the result of exchange, and spread to the Asan Bay area in the same era. Two forms of Dwelling sites coexisted dynamically in the Asan Bay area around 3,500 B.C. Such a phenomenon resulted primarily from the expansion of the dwelling site due to the introduction of primitive agriculture, as well as environmental (temperature), biological and social changes at those times.