• Title/Summary/Keyword: barren area

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Genetic Environments at the Ssangjeon Tungsten-bearing Hydrothermal Vein Deposit (쌍전 함 텅스텐 열수 맥상광상의 생성환경)

  • Sunjin Lee;Sang-Hoon Choi
    • Economic and Environmental Geology
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    • v.55 no.6
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    • pp.689-699
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    • 2022
  • The Ssangjeon tungsten deposit is located within the Yeongnam Massif. Within the area a number of hydrothermal quartz veins were formed by narrow open-space filling of parallel and subparallel fractures in the metasedimentary rocks as Wonnam formation, Buncheon granite gneiss, amphibolite and/or pegmatite. Mineral paragenesis can be divided into two stages (stage I, ore-bearing quartz vein; stage II, barren quartz vein) by major tectonic fracturing. Stage I, at which the precipitation of major ore minerals occurred, is further divided into three substages (early, middle and late) with paragenetic time based on minor fractures and discernible mineral assemblages: early, marked by deposition of arsenopyrite with pyrite; middle, characterized by introduction of wolframite and scheelite with Ti-Fe-bearing oxides and base-metal sulfides; late, marked by Bi-sulfides. Fluid inclusion data show that stage I ore mineralization was deposited between initial high temperatures (≥370℃) and later lower temperatures (≈170℃) from H2O-CO2-NaCl fluids with salinities between 18.5 to 0.2 equiv. wt. % NaCl of Ssangjeon hydrothermal system. The relationship between salinity and homogenization temperature indicates a complex history of boiling, fluid unmixing (CO2 effervescence), cooling and dilution via influx of cooler, more dilute meteoric waters over the temperature range ≥370℃ to ≈170℃. Changes in stage I vein mineralogy reflect decreasing temperature and fugacity of sulfur by evolution of the Ssangjeon hydrothermal system with increasing paragenetic time.

The Historical Survey on Knitted Works - On the Basic of the Traditional Knitting Patterns of Europe - (편물의 역사적 고찰 -유럽의 편물 전통문양을 중심으로 -)

  • 이순홍;이선명
    • Journal of the Korean Society of Costume
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    • v.50 no.7
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    • pp.195-218
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    • 2000
  • This study investigates the characteristics of European knitted works from a historical perspective. Specifically, this study deals with the following research topics: 1) the origin and development of knitting. 2) the characteristics of knitting industry according to the change of times, 3) the comparison of local knitting patterns and cultures. 4) 7he symbolic meaning of the designs in the knitted works and theire functions. This research is barred on the survey of the relevant literature and photographs. The results of the study are summarized as follows. 1) The introduction of knitted works was closely connected with the climatic and socio-economic conditions of the places of the origin. Knitted work developed mostly in Northern Europe, a cold area, and the barren, mountainous coastal areas where people frequently used woolen materials for clothes. 2) In ancient times, abstract and geometric patterns have developed in Europe under the influence of Arabian knitted work. Middle Ages saw the flourishing of Arabian knitted works representing the authority of the church. In early modern times, the knitted work assumed the wealth of the royal families and the nobles. But afterward it was gradually Popularized among the middle classes. Knitting was then regarded as one of the women's major cultural activities. However, recently in the interwar periods. the knitting industry did not flourish and the knitted works came to serve merely as comfort goods by political urge. Knitted works were introduced in Korea around 1870 (the 7th or 8th year of king Kojong era) by Catholic missionaries and they started to be made by machine in 1917. 3) As for the propagation of the knitted work into Europe, there are three routes estimated. The traditional knitting patterns of local areas and their characteristics are summed up as follows : (1) England Guernseys are thick dark blue wool, whereas Jerseys are thinner and of various colors. The knitted shawls of Shetland are world-famous for their fine, lace-like texture that they can be through a wedding-ring. The knitted work of Fair Isle shows several distinctive features, such as the use of no more than two colors, patterns with diagonal lines. symmetry within the patterns, the prominent OXO patterns, and horizontal bands of patterning. The representative knitted work of Aran is Aran sweater made for fishermen to developed from guernseys of Scotland. (2) Scandinavian countries are distinguished from other countries by their conservative but creative cultural tradition. Their knitting patterns are characterized by small geometric figures such as dots, triangles, squares, rhombuses, and crosses used often with stars and roses. Scandinavian knitting is also salient for its vertical stripes and simple motifs repeating at short intervals. (3) Baltic area : The Latvian and Lithuania stockings have very ornate patterns. Many of the Estonian knit stockings and mittens share designs. Komi was well-known for its symmetric diamond pattern. Komi patterns include colored stripes, borders of pattern and all-over designs of complex diagonals. (4) Balkan area : In Yugoslavia, the patterns of roses, leaves and flowers were used for stockings, gloves and leggings. Greek knitting resembled southern Russian knitting, which utilized light colored patterns with dark colors for a background. Turkish patterns are symmetric vertically or horizontally. 4) The traditional knitting patterns net only carried symbolic meanings but also served as means of communication. First of all, patterns had incantatory meanings. Patterns also represented Power or authenticity Patterns were symbolic of one's social standing, too. The colors, motifs and their arrangements were very important features symbolizing one's social position or family line. People often communicated by certain pieces of knitted work or patterns.

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Preliminary Study on the Application of Remote Sensing to Mineral Exploration Using Landsat and ASTER Data (Landsat과 ASTER 위성영상 자료를 이용한 광물자원탐사로의 적용 가능성을 위한 예비연구)

  • Lee, Hong-Jin;Park, Maeng-Eon;Kim, Eui-Jun
    • Economic and Environmental Geology
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    • v.43 no.5
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    • pp.467-475
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    • 2010
  • The Landsat and ASTER data have been used in mineralogical and lithological studies, and they have also proved to be useful tool in the initial steps for mineral exploration throughout Nevada mining district, US. Huge pyrophyllite quarry mines, including Jungang, Samsung, Kyeongju, and Naenam located in the southeastern part of Gyeongsang Basin. The geology of study area consists mainly of Cretaceous volcanic rocks, which belong into Cretaceous Hayang and Jindong Group. They were intruded by Bulgugsa granites, so called Sannae-Eonyang granites. To extraction of Ratio model for pyrophyllite deposits, tuffaceous rock and pyrophyllite ores from the Jungang mine used in reflectance spectral analysis and these results were re-sampled to Landsat and ASTER bandpass. As a result of these processes, the pyrophyllite ores spectral features show strong reflectance at band 5, whereas strong absorption at band 7 in Landsat data. In the ASTER data, the pyrophyllite ores spectral features show strong absorption at band 5 and 8, whereas strong reflectance at band 4 and 7. Based on these spectral features, as a result of application of $Py_{Landsat}$ model to hydrothermal alteration zone and other exposed sites, the DN values of two different areas are 1.94 and 1.19 to 1.49, respectively. The differences values between pyrophyllite deposits and concrete-barren area are 0.472 and 0.399 for $Py_{ASTER}$ model, 0.452 and 0.371 for OHIb model, 0.365 and 0.311 for PAK model, respectively. Thus, $Py_{ASTER}$ and $Py_{Landsat}$ model proposed from this study proved to be more useful tool for the extraction of pyrophyllite deposits relative to previous models.

Growth and Water Use Efficiency of Major Tree Species for Rehabilitation and the Impacts of Planting Trees on Microclimate Condition in Central Dry Zone of Myanmar (미얀마 건조지에서 주요 조림 수종의 생장과 수분이용효율 특성 및 조림이 건조지의 미세기상변화에 미치는 영향)

  • Park, Go Eun;Kim, Chan Beom;An, Jiae;Thang, Tluang Hmung;Maung, Wai Phyoe;Wai, Khaing Hsu;Kwon, Jino;Park, Chanwoo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.327-336
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    • 2016
  • The Bagan, the central part of Myanmar, is dry zone where the mean annual precipitation is less than 600 mm for the last ten years. Forest in this region has been degraded due to biotic and abiotic disturbances. While there have been various efforts to rehabilitate the degraded area, the information on growth and physiological characteristics of planting species and the impacts of planting trees in the region still lacks. Therefore, this study was conducted to determine the growth and physiological water use efficiency characteristics of five species (Azadirachta indica A. Juss., Acacia catechu Willd., Eucalyptus camaldulensis Dehn., Acacia leucophloea (Roxb.) Willd. and Albizia lebbek (L.) Willd.) which are utilized as rehabilitation species in the dry zone and to identify the impacts of tree planting on microclimate change in dry zone. The growth and the foliar carbon isotope composition of seedlings and the above mentioned five species planted in 2005 were measured. And from February 2015 to January 2016, microclimatic factors air temperature and relative humidity at 60 cm and 2 m above soil, soil temperature, soil water contents and precipitation were measured at every 30-minute interval from the two weather stations installed in the plantation located in Ngalinpoke Mt. Range. One was established in the center of A. indica plantation, and the other was in the barren land fully exposed to the sunlight. Among the five species, A. indica and A. lebbek which showed higher water use efficiency could be recommended as rehabilitation species in dry zone. Planting trees in the dry area was shown to affect the change of microclimate with shading effects, declining temperature of the land surface and aridity of the air, and to contribute to conserving more water in soil by preventing direct evaporation and containing more water with fine roots of trees.

Characteristics of Seed Germination in Heteropappus arenarius Kitam. Native to Korea as Influenced by Temperature (온도에 따른 자생 주걱쑥부쟁이의 종자발아특성)

  • Lee, Chang-Hee;Nam, Ki-Woong
    • Korean Journal of Plant Resources
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    • v.22 no.2
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    • pp.116-122
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    • 2009
  • Heteropappus arenarius Kitam., an autumn-flowering biennial belonging to wild chrysanthemums, is found to be native in southeastern coastal area and Jeju island of Korea. It could play a good role for ground cover plants on a large-scale landscape area, especially, barren soil or sloping hillside. This study was initiated to screen optimum germination temperature influenced by local strain and harvesting stage of H. arenarius. The following was the response of seed germination between local strain and temperature. The average of final germination percentage (FG) was the highest in 'Guryongpo' (89.7%) among four local strains, followed by 'Gujwa' (87.3%), 'Gampo' (87.3%), and 'HKNU-I' (71.5%). The average of $T_{50}$ was shorter in 'Gujwa' (3.6 d) and 'Guryongpo' (4.0 d) than the others. The average of FG and $T_{50}$ was the highest as 76.2% and shortest as 3.6 d in $20^{\circ}C$, respectively, followed by $30^{\circ}C$, $25^{\circ}C$, and $15^{\circ}C$. In case of 'Gujwa', however, FG and T50 was higher in $20^{\circ}C$ and shorter in $15^{\circ}C$ than others. In the relationship between harvesting stage and temperature, the average of FG was greatly higher in Stage III (90.7%) and Stage IV (88.6%) than the others including Stage II (35.7%) and Stage I (26.0%). The average of $T_{50}$ was shorter in Stage IV (3.7 d) and Stage III (4.3 d) than the others, which showed less than 50% of FG. Nevertheless, the available range of seed harvesting stage was from Stage I to Stage IV because H. arenarius seeds could germinate at all stages. In conclusion, it was recommended that the optimum temperature and harvesting stage was $20^{\circ}C$ and Stage $III{\sim}IV$, respectively, for seed germination of H. arenarius.

Studies on the Growth of Bidens L. Along the Environmental Gradient (환경구배에 따른 Bidens L.속 식물의 성장에 관한 연구)

  • 최상규;양금철
    • Korean Journal of Environmental Biology
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    • v.22 no.1
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    • pp.101-110
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    • 2004
  • The growth and niche breath of four species, i.e., native plants such as Bidens tripauita and B. bipinnata and naturalized plants such as B. frondosa and B. pilosa var. minor, were studied as related with environmental gradients including light intensity, soil moisture and soil nutrient. There were no significant differences in the phonology within each environmental gradients while considerable differences were found between species; the two naturalized species bloomed and produced fruit later than the two native species. Two naturalized species exhibited relatively higher total dry weight than the two native counterparts within all environmental gradients. Total dry weight showed positive responses to light intensity and soil moisture, and negatively to soil nutrient. The relative contribution of the environmental factors to total dry weight decreased in the order of soil nutrient, soil moisture and light intensity. Both B. bipinnata and B. pilosa var. minor showed significantly higher net assimilation rate (NAR) than other species. Also, NARs of B. bipinnata and B. pilosa var. minor decreased with increasing soil nutrient. Relative growth rate (RGR) decreased in order of B. tripartita, B. bipinnata, B. frondosa and B. pilosa var. minor in response to light intensity. In addition, RGRs of B. bipinnata and B. piEosa yay. minor increased in response to soil moisture, while those of B. pilosa var. minor and B. tripartita decreased with increment of soil nutrient. No significant fluctuations of shoot/root ratio were not observed in three species, but a native species, B. tripartita showed n decreased shoot/root ratio in response to soil nutrient. Comparing the growth characteristics of the species, B. pitosa var. minor and 3. tripartita revealed vigorous growth on barren soil. On the other hand, B. frondosa exhibited vigorous growth on fertile soil. Morphologically, B. tripartita adapted to light and required considerable moisture. On the contrary, the leaves of B. bipinnata did not change considerably in their area, although it preferred habitat with abundant light. In terms of niche breadth, B. bipinnata showed the widest ranges of 0.875 and 0.845 for light intensity and soil moisture gradients, respectively. B. pilosa var. minor showed a value of 0.933 for soil nutrient gradient. B. tripartita showed narrow ranges for the three environmental factors, whereas B. frondosa showed wide values for light intensity and soil nutrient, but relatively narrow value for soil moisture.