• Title/Summary/Keyword: Dating

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New implications on the analysis of stellar populations based on the close link between globular clusters and their host galaxies

  • Chung, Chul;Yoon, Suk-Jin;Lee, Young-Wook
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.47.4-47.4
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    • 2019
  • Recent observations on the double red clumps in the bulge validate the close connection in stellar populations between Galactic globular clusters (GCs) and the Milky Way (MW) bulge. Intriguingly, diverse phenomena observed in early-type galaxies (ETGs) and their GC systems are also indicating the similarities with Galactic GCs with multiple populations. Here, we present the population synthesis for the Galactic bulge and ETGs using stellar populations observed in the Galactic GCs with multiple populations. Our new models well explain observations of both the MW bulge and ETGs. Also, the inclusion of GC-originated population to the population synthesis model shows substantial impacts on the age-dating of stellar populations. The implication of this result for the interpretation of the formation history and the age-dating of ETGs will be discussed in detail.

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An Engineering Geological Study of Moryang Fault for Tunnel Design (터널설계를 위한 모량단층의 지질공학적 연구)

  • 방기문;우상우
    • The Journal of Engineering Geology
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    • v.10 no.3
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    • pp.237-245
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    • 2000
  • This study was for characterizing the engineering geological properties of Moryang Fault, and providing the basic data for tunnel design. Land-sat image analysis, geologic surveys, resistivity prospecting and 3-dimensional analysis for results of resistivity prospecting, core boring, mineralogical identification and chemical analysis for the bedrock, and K-Ar age dating for fault clay were carried out for the study of Moryang Fault which is located at Duckhyunri Sangbukmyun Uljinkun Ulsan metropolis. As a result of the study, it was shown that strike/dip was N20-3$0^{\circ}C$E/70-9$0^{\circ}C$NW, width of fault ranged from 20 to 60m(maximum 80m), and depth was more than 50m. K-Ar age dating results of fault clay were 5,700$\pm$1.129Ma and 1,900$\pm$0.380Ma. Hydraulic fracturing test results showed the principal stress direction similar to the strike of Moryang Fault.

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The Impact of the Self-Differentiation and Self-Disclosure of Unmarried Persons in Early Adulthood on Their Intimacy with the Opposite Sex (성인초기 미혼남녀의 자아분화와 자기개방이 이성과의 친밀감에 미치는 영향)

  • Choi, Ji-Young;Choi, Youn-Shil
    • Korean Journal of Human Ecology
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    • v.19 no.2
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    • pp.227-244
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    • 2010
  • The purpose of this study was to examine how the family of origin and self-disclosure of unmarried persons in early adulthood affected their own intimacy with the opposite sex, which was one of the major developmental tasks for them. The findings of the study are as follows: First, the self-differentiation, self-disclosure, and intimacy with the opposite sex of the single male and female adults investigated were generally at a moderate level. Second, for self-differentiation, the background variables of the male and female adults made no statistically significant difference. For self-disclosure, the background variables of the female adults made no statistically significant difference to that, but the male adults differed significantly from one another in that regard according to their family makeup and birth of order. As for connections between the background variables of the single male and female adults and their intimacy with the opposite sex, the male adults varied in that aspect with their birth order, and whether they were dating and considered getting married made a difference to that as well. In the event of the female adults, whether they considered getting married and how long they were dating made a difference in their intimacy with the opposite sex. Third, concerning the relative influence of the self-differentiation and self-disclosure of the unmarried male and female adults on their intimacy with the opposite sex, their intimacy with the opposite sex improved as division occurred from their original families, when they opened themselves up to more people, when they thought of marriage more and when they were dating for a longer period of time.

Review on the Stratigraphy and Geological Age of the Hominid Footprints-bearing Strata, Jeju Island, Korea (남제주 사람 발자국 화석을 포함한 지층의 층서와 지질 연대에 대한 고찰)

  • Kim, Kyung-Soo;Kim, Jeong-Yul
    • Journal of the Korean earth science society
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    • v.27 no.2
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    • pp.236-246
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    • 2006
  • On the basis of field observation, geology of the footprints site consists of the Kwanghaeak Basalt, unnamed strata, Songaksan Tuff, Hamori Formation, and Sand Dune, in ascending order at the Hamori-Songaksan area and the Kwanghaeak Basalt, the hominid footprints-bearing strata, and Dune Sand are consisted in ascending order at the Sagaeri area. According to the designation that the Hamori Formation overlies the Songaksan Tuff, age dating results, and geologic sequence observed in the field, the strata containing hominid footprints are not correlated with the Hamori Formation but the unnamed strata, though the strata are shown as the Hamori Formation in the geologic map. It seems to be more reasonable that the geologic age of the footprints-bearing strata is thought to be around ca 15,000 yrs B.P. according to the results of $^{14}C$ dating.

Geomorphic Development of the Kajo Basin (加祚盆地의 地形發達)

  • Jo, Wha-Ryong;Chang, Ho;Lee, Jong-Nam
    • The Korean Journal of Quaternary Research
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    • v.1 no.1
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    • pp.35-45
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    • 1987
  • Several fluvial terraces were developed in the Kajo Basin located in Kochang-gun, Kyongsangnam-do, Korea. The peat layers are formed on a fluvial terrace of them. To clarify the geomorphic development of this basin, a detailed classification of geomorphic surfaces, a soil profile study, grain size analysis, pollen analysis of the peat layers and C-14 dating were made. The main findings are as follows: 1) The Kajo Basin was formed by a differential erosion of granic rocks. The surrounding mountains are contact-metamorphosed gneiss and sedimentary rocks. 2) Seven geomorphic surfaces were recognized. They are named the H1, H2, M1, M2, T, L1 and L2 surfaces, from older to younger. 3) C-14 dating and the pollen analysis indicate that the L1 surface was formed during the Early Wurm Glacial. 4) The formation periods of the L2, M and H surfaces are supposed to be the Late Wurm, Riss and Mindel glacial, respectively, on the basis of the color of soil horizons (with or without the Red Soil) and the weathering degree of gravels. 5) Betula and Pices were dominant in the pollen of the Kajo Basin around 30,000 years B.P.

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A Luminescence Dating for a Relict Dune from the Sindu Dunefield (신두리 지역의 고사구(古砂丘)에 대한 OSL 연대 측정)

  • Seo, Jong-Cheol
    • Journal of the Korean association of regional geographers
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    • v.11 no.1
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    • pp.114-122
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    • 2005
  • To find out the buried age of the relict dune sediments, a luminescence dating bas conducted for a relict dune from the Sindu dunefield on the Taean Peninsula. It shows that the deposition of the dune sands at 3m depth began about 690$\sim$730 years ago. From 3m to l.5m depth, the lower part of the dune bas remained stable, but a relict dune deposit appear at 1.3m depth. This part yields an age of about 68 years. The two samples that were collected from the lower part of the dune at depths of the 1.5 m and 3.0 m below the surface show a net accumulation rate of around 0.75 cm/y which is relatively slow for a coastal dune. The chronology obtained in this study demonstrates that a significant amount of sediments has been replaced or remobilized in the area over the past 1000 years, and there was at least a soil formation process during the same time period. These suggest that a new approach is necessary to identify the formation age of the so-called paleo-dune at the Sind dunefield.

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Principles of Re-Os Isotopic System and Dating the Age of the Subcontinental Lithospheric Mantle Beneath Korean Peninsula (Re-Os 동위원소 시스템의 원리와 한반도 하부지각맨틀의 연령)

  • Lee Seung-Ryeol
    • The Journal of the Petrological Society of Korea
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    • v.15 no.2 s.44
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    • pp.106-117
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    • 2006
  • Re-Os isotopic system, based on the long-lived $\beta^-$ transition of $^{187}Os(\lambda=1.67\times10^{-11}year^{-1})$ is being widely used in cosmochemistry and geochemistry. Along with the development of elemental separation and mass-spectrometric technique, the Re-Os isotopic system, like Sm-Nd, Rb-Sr, U-Th-Pb isotopic system, is now conventionally applied as a useful tool for absolute dating and isotoptc tracers. This paper introduces brief principles of Re-Os isotopic system and presents the general methodology fur dating the formation age of the subcontinental lithospheric mantle, based on the Re-Os isotopic data of the mantle xeonliths from South Korea.

The Hida metamorphic belt developed near the triple junction among the Sino-Korea, Yangtze and Proto-Pacific plates

  • Kunugiza, Keitaro
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2002.05a
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    • pp.1-3
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    • 2002
  • The eastward extension of the suture zone between the Sino-Korea and Yangtze cratons in the Korean Peninsula and Japanese islands remains debatable (Hiroi, 1981; Cluzel et al., 1991; Yin and Nie, 1993; Sohma and Kunugiza, 1993; Isozaki, 1997; Arakawa et at., 2000), and is related to our understanding of the continent-continent collision orogeny. The collision orogeny varies in tectono-metamorphic processes and the timing differs from place to place, as exemplified by the absence of coesite and micro-diamond in the Korean Peninsula and Japanese islands, because it is a long-lived process of more than several tens of million years from subduction to exhumation in the Wilson cycle, and because the suture zone extends more than several thousand kilometers with a curved shape from the Qinling area of China to the Hida highland area of Japan. Hiroi (1981) is the first paper to correlate the Unazuki metamorphic rocks of the Hida metamorphic belt in Japan with the Ogcheon belt in the Korean Peninsula based on the presence of 240 Ma medium P/T metamorphic rocks in both belts, but there is a lack of recent studies on this correlation. To resolve the correlationship, there are two approaches: 1) petrological studies characterizing the origin and P-T history of rocks and 2) in-situ micro-dating of fine-grained, zoned minerals of zircon, monazite, uraninite and thorite using the EPMA (U-Th-Pb chemical dating or CHIME depending on calibration method) and the SHRIMP (Sensitive High-resolution ion Microprobe) to decipher the timing of geological events. As a first step of these approaches, micro-dating was undertaken to rocks of the Hida metamorphic belt and its Mesozoic cover (Tetori Group) in the Hida highland area, central Japan.

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Tree-ring Dating of The Palsangjeon Wooden Pagoda at The Beopjusa Temple in Boeun, South Korea

  • Jeong, Hyun-Min;Kim, Yojung;Kim, Ji-Young;Seo, Jeong-Wook
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.4
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    • pp.515-525
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    • 2016
  • The Palsangjeon Pagoda is a five-story wooden building in the Beopjusa Temple area in the Songnisan national park in Chungcheongbuk-do, Korea. According to historical records, it was constructed in either AD 1605 or AD 1626. To specify the construction year more precisely, we took 41 wood samples for tree-ring analysis during repair actions in 2013; 28 from red pine (Pinus densiflora S. et Z.), 12 from oak (Quercus spp.), and 1 from fir (Abies spp.). The tree-ring boundaries became clearly visible by smoothing their cross-sectional surface and the tree-ring widths were measured under a stereo microscope. All tree-ring series were compared with each other to establish mean chronologies, which we then compared with local master chronologies established using tree rings collected from wooden elements of the Daeungjeon Hall which is the main building in the Beopjusa Temple area. As a result, it was verified that the red pines were felled in AD 1624 and in AD 1851. Moreover, it was verified that the oaks were also felled in AD 1624 based on cross-dating with the red pine chronology. We concluded that the Palsangjeon Wooden Pagoda was constructed in AD 1626, as mentioned in the historical record (Daeungdaekwangmyeongjeonbulsangki, 1630) and the letters on a purlin on the $4^{th}$ story, using oak and red pine felled in AD 1624 and repaired later on using red pine felled in AD 1851.