• Title/Summary/Keyword: Boseong-Jangheung area

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Mesothermal Gold Mineralization in the Boseong-Jangheung area, Chollanamdo-province (전라남도 보성-장흥지역의 중열수 금광화작용)

  • 허철호;윤성택;소칠섭
    • Economic and Environmental Geology
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    • v.35 no.5
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    • pp.379-393
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    • 2002
  • Within the Boseong-Jangheung area of Korea, five hydrothermal gold (-silver) quartz vein deposits occur. They have the characteristic features as follows: the relatively gold-rich nature of e1ectrurns; the absence of Ag-Sb( -As) sulfosalt mineral; the massive and simple mineralogy of veins. They suggest that gold mineralization in this area is correlated with late Jurassic to Early Cretaceous, mesothermal-type gold deposits in Korea. Fluid inclusion data show that fluid inclusions in stage I quartz of the mine area homogenize over a wide temperature range of 200$^{\circ}$ to 460$^{\circ}$C with salinities of 0.0 to 13.8 equiv. wt. % NaCI. The homogenization temperature of fluid inclusions in stage II calcite of the mine area ranges from 150$^{\circ}$ to 254$^{\circ}$C with salinities of 1.2 to 7.9 equiv. wt. % NaCI. This indicates a cooling of the hydrothermal fluid with time towards the waning of hydrothermal activity. Evidence of fluid boiling including CO2 effervescence indicates that pressures during entrapment of auriferous fluids in this area range up to 770 bars. Calculated sulfur isotope composition of auriferous fluids in this mine area (${\delta}^34S$_{{\Sigma}S}$$\textperthousand$) indicates an igneous source of sulfur in auriferous hydrothermal fluids. Within the Sobaegsan Massif, two representative mesothermal-type gold mine areas (Youngdong and Boseong-Jangheung areas) occur. The ${\delta}^34S values of sulfide minerals from Youngdong area range from -6.6 to 2.3$\textperthousand$ (average=-1.4$\textperthousand$, N=66), and those from BoseongJangheung area range from -0.7 to 3.6$\textperthousand$ (average=1.6$\textperthousand$, N=39). These i)34S values of both areas are comparatively lower than those of most Korean metallic ore deposits (3 to 7TEX>$\textperthousand$). And, within the Sobaegsan Massif, the ${\delta}^34S values of Youngdong area are lower than those of Boseong-Jangheung area. It is inferred that the difference of ${\delta}^34S values within the Sobaegsan Massif can be caused by either of the following mechanisms: (1) the presence of at least two distinct reservoirs (both igneous, with ${\delta}^34S values of < -6 $\textperthousand$ and 2$\pm$2 %0) for Jurassic mesothermal-type gold deposits in both areas; (2) different degrees of the mixing (assimilation) of 32S-enriched sulfur (possibly sulfur in Precambrian pelitic basement rocks) during the generation and/or subsequent ascent of magma; and/or (3) different degrees of the oxidation of an H2S-rich, magmatically derived sulfur source ${\delta}^34S = 2$\pm$2$\textperthousand$) during the ascent to mineralization sites. According to the observed differences in ore mineralogy (especially, iron-bearing ore minerals) and fluid inclusions of quartz from the mesothermal-type deposits in both areas, we conclude that pyrrhotite-rich, mesothermal-type deposits in the Youngdong area formed from higher temperatures and more reducing fluids than did pyrite(-arsenopyrite)-rich mesothermal-type deposits in the Boseong-Jangheung area. Therefore, we prefer the third mechanism than others because the ${\delta}^34S values of the Precambrian gneisses and Paleozoic sedimentary rocks occurring in both areas were not known to the present. In future, in order to elucidate the provenance of ore sulfur more systematically, we need to determine ${\delta}^34S values of the Precambrian metamorphic rocks and Paleozoic sedimentary rocks consisting the basement of the Korean Peninsula including the Sobaegsan Massif.

A Preliminary Study on the Potential Source of Cadmium in the Boseong-Jangheung Mine District (전남 보성-장흥 광화대의 잠정적 카드뮴원에 대한 예비연구)

  • Heo, Chul-Ho;So, Chil-Sup;Yun, Seong-Taek;Shim, Sang-Kyun
    • Economic and Environmental Geology
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    • v.30 no.1
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    • pp.61-65
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    • 1997
  • Cadmium occurs as a minor element in sphalerite ((Zn, Fe)S) from the Boseong-Jangheung gold-silver mine district. We analyzed the abundance of cadmium in sphalerite using an electron probe micro analyzer (EPMA) and discussed the natural sources of cadmium in terms of bedrock geochemistry, in order to preliminarily reconnoiter the potential cadmium contamination in mine districts. Cadmium contents of sphalerites from the Au-Ag mines (Bodeok, Mundeok, Jeonbo, Boknae, Keumsan) in the Boseong-Jangheung district are considerably high, compared with cadmium contents of sphalerites (average = 0.5 wt.% Cd, maximum = 4.4 wt.% Cd) in the world. Sphalerites from the Keumsan mine (average = 9.49 wt.% Cd, maximum=11.22 wt. Cd) are highly enriched in cadmium. Our data suggest that the Boseong-Jangheung area is an important potential site of cadmium contamination in Korea. Based on bedrock geochemistry, natural causes of cadmium enrichment in sphalerite from the mine district are thought to be the mixing of cadmium leached from organic-rich, metasedimentary rocks (including coal) and/or black shales. From this study, we propose that the pinpointing of potential sites of pollution by toxic heavy metals can be done effectively through detailed reconnaisance study on mineralogical compositions of ore minerals such as sphalerite from the mine area.

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A Study on the Perception of Local Special Food in Gwangju and Jeonnam Area - Focused on some Housewives in Gang Jin Region - (광주.전남지역 지역특산물에 대한 인지도 조사 - 강진지역 일부 주부들을 대상으로 -)

  • Jeon, Eun-Raye
    • Journal of the Korean Home Economics Association
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    • v.44 no.6 s.220
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    • pp.155-161
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    • 2006
  • This study investigated housewives' perception of local special foods in Gwangju and Jeonnam in Gang Jin. Of 150 questionnaires sent, there were 114 responses. The most perceptible local special foods in Gwangju and Jeonnam area are as follows: Watermelon in Gwangju (100.0%), Pear in Naju (90.0%), Rice in Suncheon (40.0%), Gorosoe in Gwangyang (76.7%), Hongeo in Mopko (63.3%), Dolsan leaf mustard Kimchi in Yeosu (100.0%), Sweet Persimmon in Jangseong (86.7%), Salted bamboo sprout in Damyang (46.7%), Apple in Gokseong (90.0%), Butterfly rice in Hampyeong (63.3%), Gorosoe in Gurye (56.7%), Onion in Muan (96.7%), Peach in Hwasun(40.0%), Dallmaji rice in Yeongam (50.0%), Oyster mushroom in Jangheung (63.3%), Green tea in Boseong(96.7%), Heuksanhongeo in Sinan (53.3%), Loess sweet potato in Haenam (83.3%), Kukija in Jindo (60.0%), Laver in Wando (76.7%), Tohajeot in GangJin (73.3%), Citron in Goheung (90.0%), and Gulbi in Yeonggwang (100.0%). The most perceptible area and local special foods in Gwangju and Jeonnam area were in the following order: Green tea in Boseong (17.37%), Tohajeot in GangJin (15.97%), Watermelon in GwangJu (10.0%), Pear in NaJu (9.3%), and Loess sweet potato in Haenam (9.3%).

Occurrence of Barley Virus Diseases in Southern Part of Korea (국내 남부지역의 맥류 바이러스병 발생 현황)

  • Bae, Ju-Young;Kim, Sang-Min;Kang, Mi-Hyung;Kim, Kang-Min;Lee, Joong-Hwan;Ju, Ho-Jong;Kim, Sun-Lim;Lee, Bong-Choon
    • Korean Journal of Organic Agriculture
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    • v.23 no.4
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    • pp.859-866
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    • 2015
  • Virus disease surveys on barley cultivation areas in Jeonnam Jeonbuk Gyungnam Gyungbuk-do were conducted during 2014-2015. In this study, we detected Barley yellow mosaic virus (BaYMV), Barley mild mosaic virus (BaMMV) and Soil-borne wheat mosaic virus (SBWMV) by RT-PCR from barley leaves. These viruses are of great economic importance for wheat and barley, causing significant quantitative and qualitative losses in yield. The result of investigation showed that the field incidence of BaYMV in Buan, Gimje was more than 90% in 2014. The infection field rate of barley virus including Boseong, Gangjin, Haenam, Jangheung in Jeonnam was ${\approx}$ 30%. In 2014, double infections by BaYMV and BaMMV was detected in Boseong, Gangjin, Haenam and Jangheung. Only as a low rate BaYMV occurred in various fields of Jeonbuk in 2015. At the same time high infection field ratio of 70% was observed in Gunsan. Also in Yeonggwang was double infection of BaYMV and BaMMV. BaYMV occurred single infection has been confirmed in all of the study area of Gyungbuk and Gyungnam except for Goseong during the investigation period.

Seagrass Distribution in Deukryang Bay (득량만에 자생하는 잘피의 분포 현황)

  • Kim, Jeong-Bae;Park, Jung-Im;Lee, Kun-Seop
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.5
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    • pp.509-517
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    • 2009
  • Seagrass meadows are important biogenic habitats for a wide variety of marine animals and plants, a source of organic carbon for commercially important animals, and act as a nutrient filter in estuarine and coastal ecosystems. As such, mapping the distribution of seagrass beds provides us with an important component of management and conservation strategies. To survey seagrass distribution within Deukryang Bay, we directly observed seagrass beds using SCUBA in Boseong-gun, Goheung-gun, and Jangheung-gun. Seagrass distribution in Geogeum and Gumdang islands were not observed. Specifically, we monitored the distribution area, species composition, morphology, density, and biomass of seagrass meadows. Seagarss beds were mapped for Daikum-ri coast, Deukryang island, Yongjeong-ri coast, Samsan-ri coast and Ongam-ri coast. Total seagrass coverage in Deukryang Bay was $5.1\;km^2$, $4.8\;km^2$ of which was Zostera marina, $0.3\;km^2$ Z. caulescence and $0.01\;km^2$ Z. japonica. Z. japonica was found in intertidal zones, Z. marina was found from the intertidal to subtidal zones of 2 m MSL (mean sea level) depth, and Z. caulescence was found in subtidal zones of 2.5-5 m MSL.

Study on Nutrition Intakes of Long-Lived Men and Women Living in Seven Regions in Jellanam-do: Comparisons between Spring and Fall (전라남도 7개 지역에 거주하는 남녀 장수인의 봄과 가을 영양섭취 실태 비교 연구)

  • Chun, Soon-Sil;Jung, Su-Young;Bing, Dong-Joo;Yoon, Eunju
    • Journal of the East Asian Society of Dietary Life
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    • v.24 no.6
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    • pp.723-738
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    • 2014
  • This study examined nutrient intake of long-lived men and women living in Jeollanam-do (Gangjin, Goksung, Gurye, Damyang, Boseong, Suncheon, Jangheung) which is known as representative Korean longevity area. Using the 24 hr recall method, dietary nutrient intake data were collected from 134 subjects (67 for 80~89 years old, 67 for more than 90 years old) in spring and fall 2012. Nutrient for each subject were calculated using CAN-pro. Subjects' daily mean intake levels of macronutrients, vitamins and minerals were higher in fall than in spring. Compared to KDRIs, subjects less than recommend (RNI/AI). East consumed nutrients compared to KDRIs were folate, potassium, calcium, vitamin $B_1$, vitamin $B_2$ and vitamin E. Subjects 232.8~363.1% of recommended intake level for natrium. The nutrient adequacy ratio (NAR) was 0.87 for subjects in their 80s and 0.79 for than 90 years old. The average NAR of all subjects was 0.83. The index of nutritional quality (INQ) exceeded 1 for most nutrients except for Ca (0.87), K (0.77), vitamin $B_1$ (0.84), vitamin $B_2$ (0.70) and folate (0.68). The average INQ was 1.31. This study concluded that even though long-lived men and women living in Jeollanam-do consumed less than RNIs, nutrition consumption quality was relatively fine based on NAR and INQ results.