• Title/Summary/Keyword: K%2FAr age dating

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Widowed elderly's dating experience and related variables: focusing on gender difference (홀로된 노인의 이성교제경험과 관련변인 - 성별 차이를 중심으로)

  • Yi, Yeong Sug
    • Korean Journal of Human Ecology
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    • v.22 no.4
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    • pp.609-618
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    • 2013
  • The purpose of this study is to explore gender differences in elderly's dating experience and related variables. 427 elderly of age 65 or older participated. The results are as follows. 1. 80% of widowed elderly had no dating experience, and far more elderly men than women had dating experience. 2. Attitudes towards dating, of both elderly themselves and their children, had influence on the elderly's dating experience, regardless of gender. This indicates that the elderly's own acceptance and their children's positive attitude are important to the elderly's dating experience. 3. Gender differences were found in influences of living arrangement (whether they lived with their children or not), economical reasons, and personality factors. These variables proved significant only for the elderly men. More elderly men who did not live with their children than the elderly men who did had experienced dating, and economical reasons along with personality factors proved to be obstructive for elderly men's dating life.

Age Dating and Paleoenvironmental Changes of the Kunang Cave Paleolithic Site

  • Yum, Jong-Kwon;Lee, Yung-Jo;Kim, Jong-Chan;Kim, In-Chul;Kim, Ju-Yong
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.145-148
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    • 2003
  • The Kunang cave paleolithic site is located at Tanyang [$N37^{\circ}2'$, $128^{\circ}21'E$], Chungbuk Province, which is in the Central part of the Korean peninsula. The cave is developed at 312 amsl in a karstic mountainous area. The South Han River flows across this region and other caves can also be found near the river. The site was discovered in 1986 and excavated 3 times by the Chungbuk National University Museum until now. The cave was wellpreserved from modem human activities until the first discovery. The full length of the cave is estimated to be ca. 140 m. However, a spacious part up to 11 m from the entrance has been excavated. Eight lithological units are divided over the vertical profile at a depth of 5 m. Each unit is deposited in ascending order as follow: mud layer (Unit 9), lower complex (Unit 8) which is composed of angular blocks and fragments with a muddy matrix, lower travertine layer (Unit 7; flowstone), middle complex (Unit 6; cultural layer) which is composed of fragments with a muddy matrix, middle travertine layer (Unit 5; flowstone), yellowish muddy layer (Unit 4), upper complex (Unit 3; cultural layer) which has a similar composition to Unit 8. the upper travertine layer (Unit 2; flowstone), and finally surface soil layer (Unit 1). The most abundant vestiges in the cultural layers are the animal bones. They are small fractured pieces and mostly less than 3 cm in length. About 3,800 bone pieces from 25 animal species have been collected so far, 90 percent of them belonging to young deers. Previous archaeological study of these bone pieces shows thatprehistoric people occupied the cavenot for permanent dwelling but for temporary shelter during their seasonal hunting activity. More extensive studies of these bones together with pollen analysis are in progress to reconstruct the paleoenvironment of this cave. Only a single date (12,500 BP) obtained from a U-Th measurement of the upper travertine layer was previously available. In spite of the importance of the cave stratigraphy, there was no detail chronological investigation to establish the depositional process of the cultural layers and to understand the periodic structure of the cave strata, alternating travertine floor and complex layers. We have measured five 14C age dating (38900+/-1000, 36400+/-900, 40600+/-1600, more than 51000 and 52000 14C BP) using Seoul National University 14C AMS facility, conducted systematic process of the collagen extraction from bone fragments samples. From the result, we estimate that sedimentation rate of the cave earth is constant, and that the travertine layers, Unit 2 and Unit 3, was formed during MIS 5a(ca. 80 kBP) and MIS 5c (ca. 100 kBP) respectively. The Kunang Cave site is located at Yochonli of the region of Danyang in the mid-eastern part of Korea. This region is compased of limestones in which many caves were found and the Nam-han river flows meanderingly. The excavations were carried out three times in 1986, 1988, and 1998.

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Geology and Volcanism of Hyeongjeseom (Islet) Volcano, Jeju Island (제주도 형제섬 화산체의 지질과 화산활동)

  • Park, Jun Beom;Koh, Gi Won;Jeon, Yongmun;Park, Won Bae;Moon, Soo Hyoung;Moon, Deok Cheol
    • Economic and Environmental Geology
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    • v.54 no.2
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    • pp.187-197
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    • 2021
  • The Hyeongjeseom (Islet) is an erosional remnant of volcano which is located about 2 km northeast of sea shore of the Songaksan tuff ring, and is composed of volcaniclastic deposit, agglomerate and scoria deposit, ponded lava, aa lava flows, reworked deposit and beach deposit in ascending order from the base. The volcano is formed by volcaniclastic deposits and lava flows that recorded a transition from initial phreatomagmatic to magmatic explosions followed by lava effusion. It is interpreted that the outcropped volcaniclastic deposit may be a remaining portion of outer ring of a tuff cone. A bomb and a ponded lava yield geochemically basaltic trachyandesite compositions (SiO2 51.3 wt%, Na2O+K2O 6.0 wt%) and belong to olivine basalt with scarce (<5 %) phenocrysts of olivine, petrographically. By incremental heating Ar-Ar dating method, the plateau age of lava flow in the Heongjesom is 9.2±3.6(2σ) ka, implying that the volcanism of Heongjeseom may have occurred earlier than the Songaksan tuff ring which erupted ca. 3.7 ka. It still remains a task to find a volcano which matches with a historical record of volcanic activity that occurred a thousand years ago.

The Study on Geology and Volcanism in Jeju Island (III): Early Lava Effusion Records in Jeju Island on the Basis of $^{40}Ar/^{39}Ar$ Absolute Ages of Lava Samples (제주도의 지질과 화산활동에 관한 연구 (III): $^{40}Ar/^{39}Ar$ 절대연대자료에 근거한 제주도 형성 초기 용암 분출 기록)

  • Koh, Gi-Won;Park, Jun-Beom
    • Economic and Environmental Geology
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    • v.43 no.2
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    • pp.163-176
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    • 2010
  • We report twenty data for early lavas erupted during the initial period of formation of Jeju Island on the basis of review on 539 data of whole-rock greochemistry and $^{40}Ar/^{39}Ar$ age dating out of mainly core samples from 69 boreholes drilled in the lower land since 2001 and 66 outcrop sites. Out of 69 boreholes, the early lava flow units are identified from samples collected from Beophocheon (EL 235 m, 210 m deep), Donnaeko (EL 240 m, 230 deep), Donghong-S (EL 187 m, 340 m deep), 05Donghong (EL. 187.6 m, 340 m deep), Dosoon (EL 305 m, 287 m deep), Sangye (EL 230 m, 260 m deep), Mureung-1 (EL 10.2 m, 160 m deep), and Gapa (EL 17.5 m, 92 m deep), which are located in the southern and southwestern portion of Jeju Island. While, the well-known outcrops from Sanbangsan, Wolrabong, Wonmansa, and Kagsubawi are also reconfirmed. $^{40}Ar/^{39}Ar$ age dating results of these lavas range from 1 Ma to 0.7 Ma, indicating that the data can be useful to constrain on age and geochemical characteristics of early lava effusion period in the formation of Jeju Island. Especially, samples with trachybasalt in composition collected from 143 m to 137 m, and from 135 m to 123 m below ground surface at 05Donghong hole have the oldest ages, $992\pm21$ Ka and $988\pm38$ Ka, respectively. This study suggests that in Jeju Island the first lava with trachybasalt in composition may have effused around 1 Ma ago, and the effusion style and chemical compositions of lavas must have changed to the formation of lava domes with trachyte-trachyandesite-basaltic trachyandesite and the eruption of lavas with alkali basalt and trachybasalt intermittently during the period from 0.9 Ma to 0.7 Ma ago. It also indicates that the initial lava flows below the ground are intercalated with or underlain by the Seoguipo Formation except for several exposed domal structure areas such as Sanbangsan and Kagsubawi, implying that the early lava effusion may have intermittently and sporadically occurred with nearby hydrovolcanism and sedimentation.