• Nuclear Engineering and Technology
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• v.4 no.3
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• pp.229-240
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• 1972

Radioisotopes and their related techniques have recently been applied for scientific conservation works of cultural property and resulted many excellent findings or conservation data which could never be achieved by means of other techniques. Radiocarbon dating have widely been applied for dating the antique of organic origin, whereas the determination of radioactive contents in metal, ceramics, environmental soil, and classical objects could be able to afford many useful informations on the age, genuiness, and archeological significances as it had been produced. Trace quantity of contents of each antique have successfully been analyzed by means of radioactivation analysis or radio active tracer techniques, which could afford important technical data and results for tile conservation of each object. Radiography have also been applied for detecting the internal defects of metal objects and furthermore $\beta$-and ${\gamma}$-ray radiography were proved to be effective for such thin material as textile, painting, and fibres. In this article the detailed principle and procedures of each technique were presented so that the society could be able to make efforts to familiarize all concerns with these modern trends of the conservation techniques of cultural property.

• Journal of the Korean Geographical Society
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• v.33 no.2
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• pp.143-163
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• 1998

In order to clarify the depositional environment and sea-level change at Ilsan area including Gawaji and Saemal valley plains, which is located at the right side in downstream of the Han River, boring data, radiocabon dating and diatom analysis were comprehensively investigated. As a result, the palaeogeographies fo this area altered by the transgressions and regressions after 7,000 y. BP could be restored. The high tide sea-level(mean high water level of spring tide) was arrived ca. 7,000y. BP at the valley plain and risen to ca. 5.5m at ca. 5000y. BP. Since then, the sea-level was kept up the same level to ca. 3,200 BP. The descended sea-level to ca. 2,300 BP was risen up to ca. 5.8m in ca. 1,800 y. BP. It is presumed that such a sea-level change as well as the different sediments in quantity supplied from the river basin of the valley plain could be effected to change diversely the depositional environment of the study area and eventually to the prehistoric human life.

• 한국문화재보존과학회:학술대회논문집
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• 2006.11a
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• pp.201-206
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• 2006

• The Journal of the Petrological Society of Korea
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• v.25 no.1
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• pp.69-83
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• 2016

Radiocarbon and OSL ages of three monogenetic volcanoes inferred to be the last volcanoes on Jeju Island, Korea were determined to identify a volcano described in historical records. The results show that the ages of those volcanoes are roughly <3.8 ka (Songaksan), >4.5 ka (Biyangdo), and <6~7 ka (Ilchulbong). Though our efforts to make a positive match between historical records and volcano-chronological dating were not successful, we make a new suggestion in this paper that two historical records of volcanic activity in 1002 and 1007 A.D. could be interpreted to be the sequential volcanic events from a single monogenetic volcano. In addition, based on a volcanological reinterpretation of historical records, we infer that the volcano described therein is most likely Mt. Songaksan, in Daejeongeup, which had early phreatomagmatic and late magmatic activities after 3.8 ka ago. Furthermore, considering the geopolitical relationship between the Goryeo Dynasty and the Tamna Kingdom, in addition with the culture of the era, this study sheds new light on the possibility that there is a time gap between the actual eruptions and the historical recording of them by ancient people.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.53-62
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• 2021

Gindai (Pristipomoides zonatus) is one of six snappers in a management complex called the Deep 7 of the Hawaiian Islands. Little is known about its life history and a preliminary analysis of otolith thin sections indicated the species may exhibit moderate growth with a lifespan approaching 40 years. Preliminary age estimates from the previous study were reinvestigated using the same otolith sections in an attempt to validate those ages with bomb radiocarbon (¹⁴C) dating. From the misalignment of birth years for the otolith ¹⁴C measurements with regional references - the post-peak bomb ¹⁴C decline period - it was concluded that previous ages were inflated from overcounting of the earliest growth zone structure in otolith sections. The oldest gindai was re-aged to 26 years once the age reading was adjusted for early overcounting, 13 years younger than the original estimate of 39 years for this fish. In general, the earliest otolith growth of gindai was massive and complicated by numerous subannual checks. The approach of lumping the early growth structures was supported by the alignment of ¹⁴C measurements from otolith core material (first year of growth). The result was greater consistency of calculated birthdates with the ¹⁴C decline reference, along with minor offsets that may indicate age estimation was imprecise by a few years for some individuals. The revised von Bertalanffy growth function applied to the validated age-at-length estimates revealed more rapid growth (k = 0.378 cf. 0.113) and a lifespan of approximately 30 years. The findings presented here are a case study of how the bomb ¹⁴C decline period can be used as a tool in the refinement of age reading protocols.

• Journal of The Geomorphological Association of Korea
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• v.17 no.3
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• pp.31-47
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• 2010

The history of mass movement has been reconstructed from the Angol basin in Guryongcheon drainage basin. Sedimentary facies study, radiocarbon dating, particle size analysis, magnetic susceptibility and geomorphological analysis have been performed to reconstruct the paleo-environmental history of Angol basin. From 40,480 to 9,850yrBP there were five periods of slope instability and from 9,850yrBP to present there were at least four periods of slope instability. Magnetic susceptibility curves match well with the sedimentary facies data. This study may help reconstruct the denudational history of the small basins in Cheonan area and could be the cornerstone of the paleo-climatological study of the Korean Peninsula.

• Journal of the Korean earth science society
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• v.43 no.6
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• pp.680-690
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• 2022

Tephrochronology uses regional tephra for age dating and stratigraphic correlations. Regional tephras are important in Quaternary geology and archaeology because they can be used as stratigraphic time-markers. In this review, identification and dating methods of tephra are summarized. In addition, the characteristics of regional tephras in terrestrial deposits of the Korean Peninsula are elaborated, and geological applications and limitations of the regional tephra layers are also discussed. So far, AT, Ata, and Kb-Ks tephra layers from Kyushu, Japan have been found in Pleistocene paleosol, marine terrace deposits, and lacustrine deposits in Korea. Also, although not officially confirmed, Aso-4 tephra is likely to occur in terrestrial deposits. The regional tephra layers are vital for dating, especially with regard to sediments over 50 ka beyond the range of radiocarbon dating, and for dating of active faults. Furthermore, it can provide important information for preparing countermeasures against volcanic disasters. However, in order to use the tephra layer geologically, it must be confirmed whether it is a primary deposit based on sedimentological study.

• 보존과학연구
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• s.15
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• pp.21-32
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• 1994

Optimum conditions for benzene synthesis and liquid scintillation counting have been studied for the determination of radiocarbon age. In benzene synthesis the carbon dioxide converted to benzene with high efficiency of 91%. Yields of each step with 10L of carbon dioxide were $CO_2$ $\rightarrow$$C_2H_2$(94%), $C_2H_2$$\rightarrow$$C_6H_6$(96%) and$CO_2$$\rightarrow$$C_6H_6$(91%), respectively. Benzene synthesized from oxalate was measured with purity of 95% by GC /MS. $\delta^13$(C$^13$C/$^12$C) of oxalate was measured to $-24.7\{textperthousand}$ by massspectrometer. For liquid scintillation counting of benzene sample low background and highest FOM were measured in 0.5 ml cocktail and 3 ml standard solution with the range of 15.4∼74.9 KeV window setting. Oxalate and background samples weremeasured to $28.7\pm0.12$cpm and $3.92\pm0.04$ cpm in 15.4∼74.9 KeV

• Journal of The Geomorphological Association of Korea
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• v.17 no.2
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• pp.63-76
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• 2010

The Jangdo wetland is located on a very gentle slope of the mountain area in Daejangdo island, Shinan-gun, Korea, in which the area of the watershed is estimated at 147,000 m². The wetland has been regarded as a peat bog without any sedimentological evidence. This study was conducted to analyze the geomorphological and sedimentological characteristics of the wetland. The geographic information system (GIS) was used to analyze the drainage system, and field surveys were conducted to measure the range and depth of wetland deposits. The grain size analysis, organic matter determination, elements analysis and radiocarbon dating were performed on samples from the wetland. As a result, the wetland deposits were about 30 cm deep on average, the mean grain sizes ranged from 50 to 500 μm, and the average C/N ratio was 11.5. The portion of organic matter it contained was only 5~26%, which did not satisfy the peat standards. The radiocarbon ages from the wetland deposits range 180±50 ¹⁴C yr BP to modern, which indicated that natural and anthropogenic interferences including agricultural activities have continuously happened. We conclude that the Jangdo wetland is still in its infancy, not a steady state, so that it could be very sensitive to a small disturbance.

• Journal of the Korean Geographical Society
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• v.32 no.4
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• pp.403-420
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• 1997

Dodaecheon is a small river flowing into Asan Bay which is located in the middle part of the West Coast of the Korean Penninsula. We have investigated the change of depositional environment in Dodaecheon river basin during the middle Holocene. In the course of the research, the methods such as boring, radiocarbon dating, diatom and pollen analysis were employed. The Holocene deposits of the studied area are consisted of peat and gray silt layers, and contain many plooen and diatom fossils. Based on the results of diatom and pollen analysis, we conclude that the gray silt layers were sedimented owing to the transgression in the middle Holocene, and the peat layers by the regression or stabilzation of the sea level. The shoreline in the Post Glacial Age reached to the rivemouth of Dodaecheon at ca. 7,000 years before present(y. BP) and at that time the high tide sea-level(mean high water level of spring tide) rose to ca. 3m above present mean sea-level(m.a.s.l.). Since then to ca. 6,000y. BP, the high tide sea-level arrived to ca. 5m above present mean sea level further repeating minor transgressions and regressions. The peat layers of the coastal lowland of the West Coast were formed by the sea level fluctuations from 7,000 y. BP to 3,000 y. BP, and they were distributed 2 to 6 meters higher than the mean sea level of the present day. Most of them sedimented due to the high tide level are older and higher than those of the East Coast which were formed at the swale in the low tidal range environment.