• The Journal of the Petrological Society of Korea
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• v.2 no.2
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• pp.95-103
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• 1993

The geology of the talc ore deposits in the Chungju area consists of the Kyemyeongsan Formation, the Munjuri Formation, the Daehyangsan Quartzite, the Hyangsanni Dolomite, and the basic rocks of the Ogcheon belt. The talc ore occurs in the Hyangsanni Dolomite near the Daehyangsan Quartzite The mineral assemblages in the Hyangsanni Dolomite are \circled1calcite-tremolite-talc-quartz, \circled2calcite-talc-quartz, \circled3tremolite-calcite-dolomite, and \circled4calcite-dolomite-phlogopite-chlorite. Talc has almost the ideal composition($X_{Mg}$=Mg/(Fe+Mg)=0.98). Talc was formed in siliceous dolomite by the medium-pressure type regional metamorphism. The evidences for contact metamorphism and/or hydrothermal reaction are not clear. The metamorphic grade of the Hyangsanni Dolomite and its adjacent pelitic or basic rocks near the deposits corresponds to epidote-amphibolite facies or greenschist facies based on the, mineral assemblages of \circled1hornblendebiotite-muscovite-epidote-quartz \circled2biotite-chlorite-quartz, and \circled3hornblende-actinolite-plagioclasequartz. The formation of the talc deposits were caused by the following reactions due to greenschist facies metamorphism of siliceous-dolomitic rocks in the Hyansanni Dolomite. (I) 3 dolomite+4 quartz+$H_2O$= talc+ 3 calcite +3 $CO_2$; (11) 3 tremolite+ 2 $H_2O$+ 6 $CO_2$= 5 talc+ 6 calcite + 4 quartz. The minimum temperature of the talc-tremolite-quartz assemblage is about $434^{\circ}C$ from calcite thermometry and the carbon dioxide mole fraction in metamorphic fulid($X_{$CO_2$}$) is about 0.1 at assumed pressure, 3 kbar.

• 한국해양학회지
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• v.21 no.3
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• pp.156-170
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• 1986

The phytoplankton ecology of estuarine waters was investigated in the Kyeonggi Bay from May 1981 to September 1982 on monthly basis. In this study area, a total of 228 phytoplankton species was identified. Among these taxa, the most dominant species are diatoms in this area. Tychopelagic plankton occupies 40.4% of total species. The percentage of tychopelagic plankton density ranged from 10.2% in September to 92.7% in March of monthly standing crops. From late autumn to early spring, the percentage values are more than 72%. They play an important role from late autumn to early spring in this estuarine plandton community. These tychopelagic planktons are induced from benthic diatoms. Because the bottom shear stresses generated by the tides and winds are stronger than the adhesive and tractive force of benthic diatoms, most of benthic diatoms must be resuspended into tychopelagic suspensions during autumn and winter. Paralia sulcata is the most important tychopelagic plankton as an indicator species of water mixing in the eastern coastal area of Yellow Sea. This species seems to have even broader tolerance to the environmental stress than Skeletonema costalum, and tends to fill the gaps in winter, when the phytoplandton is relatively unsuccessful. Skeletonema costatum and Chaetoceros debilis are dominant in other seasons. Typical blooms of phytoplankton occur in spring and early autumn, The first bloom is started by Skeletonema costatum in early May, second peak is formed by various diatom population in September.

• Journal of the Mineralogical Society of Korea
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• v.17 no.2
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• pp.135-145
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• 2004

A zeolitic bentonite, which exhibits whitish appearance and contains considerable amounts (nearly 〉 5%) of zeolites, frequently occurs as thin beds less than 1 m in Yeongil area. The bentonites are mostly found in closely association with zeolite beds in the Nuldaeri Tuff and Coal-bearing formations of the Janggi Croup. A discordant occurrence of the bentonite against the bedding plane is also locally found. Montmorillonite, the major mineral constituent of the bentonite, is mostly associated with clinoptilolite as a zeolite. However, instead of clinoptilolite, mordenite is sometimes included in the case of more silicic bentonite, and heulandite in the less silicic one. It is characteristic that the mordenite is accompanied by lots of opal-CT in the silicic bentonite. SEM observations characteristically indicate that these authigenic phases, especially the montmorillonite and zeolite, nearly coexist as mixtures not forming a fine-scale zoning. The zeolitic bentonite seems to be formed in the comparatively silicic pore fluid at the alkaline condition accompanying pH fluctuation Compared to the zeolite-free normal bentonite, the zeolitic types exhibit somewhat higher REE abundance. These chemical characteristics, together with modes of occurrences and authigenic mineral associations, may suggest that the zeolitic bentonite is not merely diagenetic products and a possible hydrothermal alteration could not be excluded in the bentonite genesis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.1
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• pp.107-114
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• 1983

The study was carried out to find out the reasonable fertilization method for rice in the area of Irish potato cultivated paddy where has various nutritional disorders and pest problems. The treatment consisted of three different application methods of potato sterns and leaves with 4 levels of nitrogen application in each method. The application of potato sterns and leaves caused more release of $NH_4$ -N in the soils but the growth of rice were slightly hindered by the strongly reduced soil conditions when the nitrogen had been applied more than 10kg/10a. The application of half-dried or semi-decomposed stems and leaves of potatoes were caused to increase ripening ratio and 1,000 grain weight of rice with a relatively high $SiO_2$/N ratio in the rice plant, so the yield of rice increased 3-5% than the plot without potato sterns and leaves. The potash and silicate fertilizer would seem to be effective in the area of Irish potato cultivating paddy field since the contents of extractable potassium and soluble silicate in the soils is lacked. The suitable amount of nitrogen on rice cropping seems to be about 7kg/10a.

• Communications of Mathematical Education
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• v.11
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• pp.259-277
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• 2001

본 연구는 개방형 문제를 활용한 평가가 수학적 창의력에 미치는 효과를 분석함으로써 수학적 창의력을 신장시킬 수 있는 평가 방법을 찾는데 그 목적이 있다. 이를 위해 대구광역시 소재의 C중학교 2학년 1개반과 S중학교 2학년 1개반을 임의로 선정하여 한 반은 개방형 문제를 활용한 평가 집단으로 하고 다른 한 반은 전통적 평가 집단으로 무선 할당하여 실험연구를 실시하였다. 실험처치는 두 집단에게 서로 다른 유형의 평가를 실시하는 것으로, 실험집단은 개방형 문제를 평가과제로 하여 실험집단 담임 교사가 평가를 실시하였으며, 비교집단은 객관식 및 주관식 단답형 문제를 평가과제로 하여 비교집단 담임교사가 전통적인 평가를 실시하였다. 본 연구에서 사용한 검사도구는 수학적 창의력 검사로 사전 사후검사 모두 같은 검사지를 사용하였다. 사후 수학적 창의력 검사의 평균의 차를 t-검정한 결과 유의도p=.025(p < .05)로 실험집단과 비교집단 사이에는 통계적으로 유의미한 차가 있는 것으로 나타났다. 수학적 창의력의 각 요소별로 차이가 있는지 알아보기 위해 사후 창의력 검사의 각 요소별로 평균의 차를 t-검정한 결과, 유창성과 융통성은 각각 유의도 p=.030, p=.040으로 p < .05 수준에서 통계적으로 유의미한 차이가 있었으며, 독창성은 유의도 p=.052로 p < .1 수준에서 통계적으로 유의미한 차이를 보였다. 연구결과 개방형 문제를 활용한 평가가 전통적 평가보다 수학적 창의력 향상에 더 효과적이며, 수학적 창의력의 세 가지 요소(유창성, 융통성, 독창성)의 향상에도 효과적인 것으로 나타났다. 결론적으로 개방형 문제를 활용한 평가가 수학적 창의력 신장에 효과적인 방법임을 시사한다.질공학적 특성의 위도별, 깊이별 변화는 탄산질 퇴적물과 규질 퇴적물의 분포, 수층의 생산성 및 수심변화에 따른 용해도와 퇴적을 차이 그리고 침식 및 재퇴적작용 등 퇴적 과정이 위도별로 달랐기 때문으로 판단된다.haetoceros resting spores/Chaetoceroe vegetative cells도 80 cm 보다 상층에서는 높게 나타나 규조온도지수 분포와도 일치하는 경향을 보인다. 이상의 규조군집 분석 결과에 의하면, 홀로세의 후빙기동안 본 연구 지역인 동해 북동부에는 대마 난류의 유입이후 현재와 유사한 환경이 우세하게 발달했으나, 난류종 P. doliolus의 변화는 동해내에서 대마난류의 세기가 반복되었음을 지시하고 있다./3 수준으로 높다. 결론적으로 풍부한 화학물질들을 함유한 제주해류는 남해 및 동해의 생지화학적 과정들에 있어 상당히 중요함을 시사한다.다. 수조 상층수 중 Cu, Cd, As 농도는 모든 FW, SW수조에서 시간이 지남에 따라 일관성 있게 감소하였고, 제거속도는 Cu가 다른 원소에 비해 빨랐다. 제거속도는 FW 3개 수조 중 FW5&6에서 세 원소 모두 가장 느렸고, SW 3개 수조 중에서는 SW1&2에서 가장 빨랐다. SW와 FW간 제거속도 차이는 세 원소 모두 명확치 않았다 Cr은 FW에서 전반적으로 감소하는 경향을 보였지만 SW에서는 실험 초기에 감소하다 24시간 이후에는 증가 후 일정한 양상을 보였다. Pb은 FW에서 전반적으로 감소했지만 SW에서는 초기에 급격히 증가 후 다시 급격히 감소하는 양상을 보였다 Pb 또한 Cu, Cd, As와 마찬가지로 SW1&2에서 제거속도가 가장 빠르게 나타났다. FW 상층수 중 Hg는 시간에 따라 급격히 감소했고,

• Journal of the Mineralogical Society of Korea
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• v.2 no.2
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• pp.73-80
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• 1989

The sedimentary siderite rock or siderostone has been firstly found from the upper part of the Cambrian Myobong Slate in the Sangdong Tungsten Mine area. It occurs as layers between slate and calc-silicate rock (originally siliceous ankerite rock and ferroan dolostone) or within calc-silicate rock. Some parts of the siderostone bed, however, are considerably skarnized to iron-rich skarns, leaving only small-scaled relics. Siderostone consists mainly of siderite and quartz with minor amount of bertioerine and fluorite or apatite and is commonly microcrystalling granular in texture. Stratification is well developed in some siderstone. The siderostone and its skarnized rocks occasionally contain scheelite grains. Siderite also occurs in sandstone and slate. Mineralogy and textures of the siderostone suggest that it might be formed in the shallow marine basin where enough organic matter was present to maintain a low Eh and iron was supplied, and that siderite might be formed largely by diagenesis from iron-rich berthierine mud.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.1
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• pp.11-19
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• 1982

The average weight of larvae, the percentage of survival larvae and the percentage of moth emergence in first and second generation of striped rice borer showed lower values in Akibare(Japonica variety) compared with those in Milyang 23 (Indica variety). At higher nitrogen level the larvae weight in second generation of striped borer was increased. The percentage of survival larvae in second generation was gradually decreased by applying the silicate fertilizer in both cultivars. The moth emergences in both generations of striped rice borer were also lower at high levels of silicate fertilizer. The percentage of white head of rice plant was reduced by the application of silicate fertilizer. The ratio of SiO$_2$ to T-N of the rice stem was related negatively with the percentage of survival larvae and the moth emergence in second generation of striped rice borer, and also with the percentage of white head of rice plant.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.467-476
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• 2017

Volcanic rocks related to the Guamsan cadera, which find in the southeastern Cheongsong, are divided into Volcanic breccia, Guamsan Tuff and Post-collapse intrusions. We determined their eruption, intrusion and caldera-forming timings based on SHRIMP U-Pb zircon dating. The dating results yield earlier eruption age of $63.77{\pm}0.94Ma$ from the lower ash-flow tuff and an later eruption age of $60.1{\pm}1.8Ma$ from the upper ash-flow tuff of the Guamsam Tuff, and intrusion age of $60.65{\pm}0.95Ma$ from the rhyolite ring dyke of the Post-collapse intrusions. The age data suggest that the Guamsan caldera is formed in 60.65~60.1 Ma between eruption of the upper ash-flow tuff and intrusion of the rhyolite ring dyke. The Guamsan cadera exhibits the volcanic processes of a perfect igneous cycle passing from ash-flow eruptions through caldera collapse to ring intrusions during 63.77~60.1 Ma.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.271-278
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• 1999

In order to clarify water quality, dynamics and structure of phytoplankton communities, and red tides, the present study was carried out monthly from July to September 1998 at 19 stations in Deukryang Bay. Water temperature varied from 24.$0^{\circ}C$ to 28.6$^{\circ}C$, and salinities ranged from 25.0$\textperthousand$ to 28.6$\textperthousand$. During red tides in July, chlorophyll-$\alpha$ contents were rather high in August, it showed that phytoplankton controlled primary production in this bay. Phytoplankton was composed of 89 diatoms, 19 dinoflagellates, and 3 silicoflagellates. Phytoplankton standing crops varied from a minimum of 1.3$\times$10$^4$cells/ι(Sept., St. 17) to a maximum of 3.8$\times$10$^{6}$ cells/ι (July, St. 10). Red tides occurred in July when the standing crops averaged 1.8$\times$10$^{6}$ cells/ι. Leading the causative organisms of red tide were Prorocentrun minimum in the upper bay, Chaetoceros curvisetus in the mouth and middle part of the bay, Ceratium furca and Thazassio- sira sp. around Nokdong Harbour. Concentration of nutrients such as nitrogen was high in the upper bay, during red tides, water temperatures varied from 23.8$^{\circ}C$ to 29.7$^{\circ}C$ and salinity were 23.l$\textperthousand$ to 27.0$\textperthousand$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.474-483
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• 2015

In order to understand the seasonal change of phytoplankton as well as the effect of water physico-chemical parameters, we investigated 18 stations in coastal areas of the East Sea in February, May, August and November in 2009. The taxa of phytoplankton observed in this study were classified as 37 Bacillariophyceae, 22 Dinophyceae, 1 Euglenophyceae, 3 Dictyophyceae and 1 Cryptophyceae. Phytoplankton abundance ranged from $1.2{\times}10^3cells/L$ to $246.6{\times}10^3cells/L$(with a mean value of $24.8{\times}10^3cells/L$), the highest biomass was observed in May. The dominant species were Leptocylindrus danicus, Chaetoceros affinis, Pseudo-nitzschia pungens, Thalassionema nitzschioides and etc. Pearson's correlation co-efficient between phytoplankton abundance and other water parameters showed the positive relationships with pH, DO, Secchi-disk depth, and SS, the negative relationships with $SiO_2-Si$. Seasonal patterns of phytoplankton dominant species were affected by the characteristics of water masses based on T-S diagram analysis. In particular, phytoplankton distributional patterns were related with water temperature in May and salinity in August, respectively. According to the result of MDS(Multi-dimensional scaling) using the phytoplankton abundance and species composition, the spatial distribution of phytoplankton were characterized with Ganwon(Group A) and Gyeongbuk(Group B) at the coastal areas of Jukbyeon or Uljin.