• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.1
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• pp.9-13
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• 2007

Hexane extract of Porteresia coarctata (Roxb.) exhibits a toxic effect on the tissues of Spodoptera litura (F) while fed at the dose of 1000 and 2000 ppm thoroughly mixing with castor leaves (Ricinus communis L) after dissolving in DMSO at late fourth instar whereas only DMSO treated castor leaves were fed to control group. The larvae were put to rear at $28^{\circ}C{\pm}1^{\circ}C$, $76{\pm}4%$ R.H. under 12 L + 12 D photoperiodic regime. In test group insects substantial reduction of protein and DNA content was marked in fat body and midgut tissues compared to DMSO treated control group. The significant biochemical alterations in the midgut tissues and fat body of test group insects indicate the insecticidal property of the said plant extract that could be tested in facilitating the phenomenal stride in Integrated Pest Management.

• Economic and Environmental Geology
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• v.28 no.2
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• pp.93-108
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• 1995

The Bobae sericite deposit occurs in rhyodacite of the Cretaceous volcanogenic sedimentary rocks, Upper Yucheon Group, in the western part of Pusan. The alteration zones are divided into the phyllie and prophylitic zone based on the mineral assemblages. The phyllic zone is subdivided into three subzones; Andalusite-Pyrophyllite, Sericite and Albite subzones. Oxides vs. $Al_2O_3$ contents show variations corresponding to mineral assemblage in each alteration zone. On the basis of bulk chemical compositions, it was found that $SiO_2$ increases in the Andalusite-Pyrophyllite subzone and $K_2O$ in the Sericite subzone. The oxygen, hydrogen and sulfur isotope analysis indicates that the fluids were originally derived from the residual magmatic solution. It has been mixed with abundant meteoric water later. The ore-forming temperatures obtained from sericite (illite) geothermometer are about $250{\sim}350^{\circ}C$. Considering the phase stability relation, PoT conditions of the andalusite-pyrophyllite subzone were estimated to be less than 0.5 kb and almost $400^{\circ}C$, respectively. The K-Ar ages of sericites indicate that the clay deposit is genetically related to the Cretaceous-Paleogene Masan Hornblende-Biotite Granite.

• Economic and Environmental Geology
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• v.32 no.5
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• pp.421-434
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• 1999

Gas and chemical compositions of fluid inclusions in quartz some of Au-Ag, Pb-Zn-Cu and W-Mo mineral deposits in South Kores were analyzed to interpret the sources of ore fluid and the depositional condition of ore minerals in base-metal ore deposits. Fluid inclusions in quartz from the gold and silver mines are characterized by $CO_2$ rich fluids which have a wide range in $CH_4 \;and\; CO_2$ contents ($CH_4/CO_2$=0.001-0.225). The $CO_2$ rich but $CH_4$-poor nature of the fluid reflects the high fo2 condition during the mineral precipitation. The C2H6 is detected in hydrothermal quartz vines in metasedimentary rocks from the Jeonjoo-il, Youngbokari and Taechang mines. The $CH_4 /CO_2$ rations in W-Mo bearing quartz veins range from 0.005 to 0.214, which is similar with those in Au-Ag mines. However, skarn formation stage. Fluid inclusions, A relatively good correlation between Na and Cl contentrations reflects varible salinity in the fluid inclusion, it is suggested that the chemistry of promary magmatic hydrothermal fluids has changed during post-magmatic alteration and/or wall rock alteration processes. The content of gas compositions also depends on the kinds of country rocks, supporting above conclusion.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.142-142
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• 2019

하천 생태환경은 토지이용, 댐건설 및 기후변화 등 외부의 압력에 따른 변화로 인해 오염물 유입, 녹조 발생, 어패류 떼죽음 등 생태계 교란 및 환경변화가 발생한다. 이러한 생태환경 문제를 해결하기 위해 전 세계적으로 하천생태환경시스템 복원이 논의되고 있으며 환경적 측면을 강조한 자연친화적 하천을 목표로 개발 방향이 바뀌고 있다. 이처럼 하천생태환경의 중요성이 커지고 있지만 보다 객관적이고 정량적인 평가를 위한 연구는 부족한 실정이다. 본 연구에서는 낙동강 감천유역을 대상으로 하였으며, 김천부항댐 건설로 인한 생태환경시스템의 변화를 정량적으로 평가하고자 수문변화지표법(Indicators of Hydrologic Alteration, IHA)을 활용하여 33개의 수문변화지표군(IHA Parameters)과 34개 환경유량지표군(Environmental Flow Components Parameters)을 산정하였다. 분석을 위하여 감천유역 선산관측소의 2007년 ~ 2018년까지의 일 유량 자료를 활용하였으며, 댐이 건설된 2014년 1월 1일을 기점으로 댐 건설 전(2007 ~ 2013)과 댐 건설 후(2014 ~ 2018)가 하천생태환경 및 환경유량에 미치는 영향을 평가하였다. 본 연구를 토대로 지속가능한 하천생태계 보전을 위한 명확한 목표와 효율적인 평가과정을 수립하는 데 도움이 될 것으로 보인다.

• Economic and Environmental Geology
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• v.47 no.5
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• pp.489-496
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• 2014

The occurrence and mineralogical characteristics of asbestos in dolostone at Ungdo, Seosan were investigated by analyses of PLM, XRD, and SEM/EDS. Representative outcrops of dolostone at Ungdo were examined and four dolostone samples were collected according the occurrence type to identify the shape of asbestos in dolostone samples. The host rock of dolostone had been produced from the hydrothermal alteration and/or thermal metamorphism of which main source was assumed as the acidic granite. Tremolites were observed near the cracks or fractures of the dolostone as tamping or gob types. From the mineralogical analyses, main minerals of dolostone were dolomite with calcite, quartz, talc, amphibole, and pyroxene. From SEM/EDS analyses, tremolite-actinolite asbestoses were observed in dolostone and their shapes were prismatic and fibrous (less than $1{\mu}m$ in width). Non-asbestos prismatic forms were also found and they would transfer to asbestos particles resulting from the cleavage and fracture of the prismatic particles. Overall results suggest that asbestoses in Ungdo dolosotnes were mainly tremolite-actinolite and they were originated from the hydrothermal alteration of Ca-Mg rich dolostone.

• Economic and Environmental Geology
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• v.50 no.1
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• pp.15-26
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• 2017

Advanced argillic, argillic, and phyllic zones are the most important alteration patterns to predict the hidden ore body during exploration of hydrothermal deposits. We examined the quantitative relationship between the spectral absorption characteristics and the mineral content of the synthetic mixtures such as alunite-kaolinite and illite-kaolinite using short wavelength infrared (SWIR) spectroscopy. In the alunite-kaolinite mixtures, the spectral absorption characteristics of the alunite was highly correlated with the Hull quotient reflectance(0.99) and the kaolinite had the highest correlation with the Gaussian peak(0.92). Illite-kaolinite mixtures are essential for Gaussian deconvolution because of the overlap of absorption region. Illite and kaolinite mixtures indicate the high correlation of 0.93 and 0.98, respectively. The error ranges in the alunite-kaolinite(8%) and illite-kaolinite mixtures(5%) derived from SWIR were smaller than the ones(29% and 26%) obtained from X-ray diffraction(Rietveld) analysis. These results show that SWIR spectroscopic analysis is more reliable than XRD Rietveld analysis in terms of quantification of allowed minerals.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.269-274
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• 2006

The purposes of this research are, first, to investigate the present condition of indoor thermal environment in winter. Second, to find out how residents' knowledge, consciousness, and behavior changed after provided with education and information of indoor climate. Finally, to reveal how this changes make alteration to their indoor environment. Thirty apartments were collected, and then divided into three groups as Control Group, Education Group, and Edu-information Group in order to conduct the purposes. Provided education and environmental information turn out to have a positive effect to residents' knowledge, consciousness, and behavior, and consequently, it leads residents to control their indoor environment more actively in some cases. Thus, it is important to provide residents with environmental education and information, and it should be conducted regularly in order to maximize the positive effect of education since it tends to decrease as time goes by.

• Economic and Environmental Geology
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• v.21 no.1
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• pp.1-15
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• 1988

This is a study on the mineral compositions, SK numbers of refractoriness and the genesis of the clay mineral deposits in Cheonnam Province and Handong area. 1. Jindo kaolin deposits: Chief clay minerals of the deposits are kaolinite, quartz and alunite. The SK number of the ore is from $34^+$(the highest) to 27(the lowest). On the genesis of the deposits some geologists believe that the deposits were formed by the alteration of the siliceous tuff. But the deposits seems to be formed by the hydrothermal alteration of the rhyolite lava beds. This area is formed by alternative beds of tuff; and kaoline deposits. 2. Hadong area: Chief mineralogy of Hadong kaolin area is $10{\AA}$ halloysite and kaolinite. The SK number of some of the ore is up to $36^+$. The theoretic SK number of kaolinitic composition is 35. So one of the highest alumina minerals of gibbsite is formed in the ores of $36^+$ SK numbers. 3. Hampyong kaolin deposits: Most of kaolin has black color. The chief minerals are kaolinite, quartz and muscovite. Some of the kaoline contains rutile crystals. SK number ranges from 30 to 17. The kaolin deposit is formed by the transported sedimentation in lower part of the seashore. 4. Jangsan kaoline deposits: Chief minerals of the kaolin is kaolinite, quartz and muscovite. Some kaoline contains small crystals of pyrite. This area consists almost of the tuffs. Kaolin deposits also would be formed by the alteration of the tuffs. 5. Nohwado pyrophyllite deposits: Quartz and pyrophyllite are chief minerals. SK number of the ore ranges from 32 to 30. The pyrophyllite deposits would be formed by the hydrothermal alteration of the rhyolitic lava beds. This area consists of alterative beds of tuffs and rhyolitic lavas. 6. Songsuk pyrophyllite deposits: Chief minerals are quartz, kaolinite, pyrophyllite and iron oxides. In the pyrophyllite deposits egg-like inclusions of diaspore and kaolinite in composition. This area almost consists of tuffs. Several faults are developed and along the fault the tuff would begin to alter to pyrophyllite and some parts to diaspore and kaolinite nodules by the acts of hydrothermal solution.

• Economic and Environmental Geology
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• v.30 no.4
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• pp.279-289
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• 1997

Dark to pale green-colored, Cr-bearing sericites from hydrothermal alteration zone of the Narim gold deposit were investigated mineralogically and geochemically. The alteration zone is composed mineralogically of quartz, carbonate minerals and green sericite with minor amounts of chlorite, barite and sulfide minerals (pyrite, sphalerite, galena). The zone is enriched in As (967 to 1520 ppm), Cu (31 to 289 ppm), Ni (1027 to 1205 ppm), Pb (0.20 to 1.24 wt.%) and Zn (1.03 to 1.07 wt. %) compared with fresh rocks such as granitic gneiss, porphyritic biotite granite and basic dyke. The Cr, probably the chromophore element, is highly enriched in the alteration zone (1140 to 1500 ppm), host granitic gneiss (1200 ppm) and porphyritic biotite granite (1200 ppm). Occurrence and grain size of sericite are diverse, but most of the Cr-bearing sericites (150 to $200{\mu}m$ long and 20 to $30{\mu}m$ wide) occur along the boundaries between ore veins and host rocks (especially basic dyke and granitic gneiss). X-ray diffraction data of the sericite show its monoclinic form with unit-cell parameters of $a=5.202{\AA}$, $b=8.994{\AA}$, $c=20.103{\AA}$, ${\beta}=95.746^{\circ}$ and $V=935.83{\AA}^3$, which are similar with the normal 2M1-type muscovite. Representative chemical formula of the sericite is ($K_{1.54}Ca_{0.03}Na_{0.01}$)($Al_{3.42}Mg_{0.38}Cr_{0.14}Fe_{0.06}V_{0.02}$)($Si_{6.69}Al_{1.31}$)$O_{20}(OH)_4$. The Cr content increases with decrease of the octahedral Al content, and ranges from 0.36 to 2.58 wt.%. DTA and TG curves of the sericite show endothermic peaks at $342^{\circ}$ to $510^{\circ}$, $716^{\circ}$ to $853^{\circ}$ and $1021^{\circ}C$, which are due to the expulsion of hydroxyl group. The total weight loss by heating is measured to be about 8.8 wt. %, especially at $730^{\circ}C$. Infrared absorption experiments of the sericite show broad absorption band due to the O-H bond stretching vibration near the $3625cm^{-1}$, coupled with the 825 and $750cm^{-1}$ doublet. The vibration bands related with the H-O-Al and Si-O-Al bonds occur at $1030cm^{-1}$ and 500 to $700cm^{-1}$, respectively. Based on paragonite content of the sericite, the formation temperature of the Narim gold deposit is calculated to be $220{\pm}10^{\circ}C$.

• Economic and Environmental Geology
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• v.44 no.5
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• pp.359-372
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• 2011

TA26 seamount, which is located at south part of Tonga arc, occurs widely hydrothermal plume and is area that sampled hostrock, hydrothermal ore and hydrothermal alteration rock for this study. Hostrocks are basalt and basaltic andesite. Altered rocks by hydrothermal solution consists of plagioclase, pyroxene, pyrite, ilmenite, amorphous silica, barite, smectite, iron sulfates, Fe-Si sulfates and Fe silicates. Gains and losses of major, trace and rare earth elements during wallrock alteration suggest that $K_2O$(+0.04~+0.45 g), $SiO_2$(-6.52~+10.56 g), $H_2O$(-0.03~+6.04 g), $SO_4$(-0.46~+17.54 g), S(-0.46~+13.45 g), total S(-0.51~+16.93 g), Ba(-7.60~+185078.62 g), Sr(-36.18~+3033.08 g), Ag(+54.83 g), Au(+1467.49 g), As(-5.80~+1030.80 g), Cd(+249.78 g), Cu(-100.57~+1357.85 g), Pb(+4.91~+532.65 g), Sb(-0.32~+66.59 g), V(-113.58~+102.94 g) and Zn(-49.56~+14989.92 g) elements are enriched from hydrothermal solution. Therefore, gained(enriched) elements(($K_2O$, $H_2O$, $SO_4$, S, total S, Ba, Sr, Ag, Au, As, Cd, Cu, Pb, Sb, V, Zn) represent a potentially tools for exploration of sea-floor hydrothermal deposits from the Tonga arc.