• Economic and Environmental Geology
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• v.44 no.6
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• pp.463-474
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• 2011

The Haenam epithermal mineralized zone is located in the southwestern part of South Korea, and hosts low sulfidation epithermal Au-Ag deposit (Eunsan-Moisan) and clay quarries (Okmaesan, Seongsan, and Chunsan). Epithermal deposits and accompanying hydrothermal alteration related to Cretaceous volcanism caused large zoned assemblages of hydrothermal alteration minerals. Advanced argillic-altered rocks with mineral assemblages of alunite-quartz, alunite-dickite-quartz, and dickite-kaolinite-quartz exposed on the Okmaesan, Seongsan, and Chunsan area. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), with three visible and near infrared bands, six shortwave infrared bands, and five thermal infrared bands, was used to identify advanced argillic-altered rocks within the Haenam epithermal mineralized zone. The distinct spectral features of hydrothermal minerals allow discrimination of advanced argillic-altered rocks from non-altered rocks within the study area. Because alunite, dickite, and kaolinite, consisting of advanced argillic-altered rocks within the study area are characterized by Al-O-H-bearing minerals, these acid hydrothermal minerals have a strong absorption feature at $2.20{\mu}m$. The band combination and band ratio transformation cause increasing differences of DN values between advanced argillic-altered rock and non-altered rock. The alunite and dickite-kaolinite of advanced argillic-altered rocks from the Okmaesan, Seongsan, and Chunsan have average DN values of 1.523 and 1.737, respectively. These values are much higher than those (1.211 and 1.308, respectively) of non-altered area. ASTER images can remotely provide the distribution of hydrothermal minerals on the surface. In this way good relation between ASTER spectra analysis and field data suggests that ASTER spectral analysis can be useful tool in the initial steps of mineral exploration.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.413-426
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• 2009

The study was conducted to investigate the effects of indigenous bacteria on geochemical behavior of toxic heavy metals in contaminated paddy soil near an abandoned mine. The effects of sulfate amendment to stimulate microbial sulfate reduction on heavy metal behaviors were also investigated. Batch-type experiments were performed with lactate or glucose as a carbon source to activate indigenous bacteria in the soil under anaerobic condition for 100 days. Sulfate (250 mg/L) was artificially injected at 60 days after the onset of the experiments. In the case of glucose supply, solution pH increased from 4.8 to 7.6 while pH was maintained at 7~8 in the lactate solution. The initial low pH in the case of glucose supply likely resulted in the enhanced extraction of Fe and most heavy metals at the initial experimental period. Lactate supply exerted no significant difference on the amounts of dissolved Zn, Pb, Ni and Cu between microbial and abiotic control slurries; however, lower Zn, Pb and Ni and higher Cu concentrations were observed in the microbial slurries than in the controls when glucose supplied. Sulfate amendment led to dramatic decrease in dissolved Cr and maintenance of dissolved As, both of which had gradually increased over time till the sulfate injection. Black precipitates formed in solution after sulfate amendment, and violarite($Fe^{+2}{Ni^{+3}}_2S_4$) was found with XRD analysis in the microbial precipitates. Conceivably the mineral might be formed after Fe(III) reduction and microbial sulfate reduction with coprecipitation of heavy metal. The results suggested that heavy metals which can be readily extracted from contaminated paddy soils may be stabilized in soil formation by microbial sulfate reduction.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.1
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• pp.1-8
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• 2012

This study was carried out in 2010 to investigate the utilization and forage quality of native grasses, such as $Phragmites$ $communis$ which might reduce the cost of feeding domestic cattle. The regions surveyed were the Haenam ranch in Haenam, Pyeongchang, Wonju, and Yeonggwang. In Haenam, yearly silage production harvested from 300 ha was 2,000 MT (7 MT/ha). All of those round bale silages were self-consumed in that region, and marketing price was 50,000~55,000 won per roll (110 won/kg). $Phragmites$ $communis$ of 150 cm in length contained 8.4% crude protein (CP) with relative feed value (RFV) 71.9 and 60.1% in vitro dry matter digestibility (IVDMD), which was somewhat more favorable than forage quality of rice straw. The silage quality of $Phragmites$ $communis$ varied greatly by the time of harvest (CP 4.7~6.4%, RFV 62.2~78.9, and IVDMD 41.9~53.9%), even with the same district and of the same original forage materials. Generally, the quality of $Phragmites$ $communis$ silage of was poorer than that of sorghum ${\times}$ sudangrass hybrid. In Pyeongchang, forage quality of $Phragmites$ $communis$ was decreased from 13.9% to 7.6% in CP, 90.7 to 76.1 in RFV, and 72.9% to 54.7% in IVDMD, as plant was getting mature, from 79 cm to 117 cm, 121 cm or to 142 cm in length. In Wonju, the quality values of $Phragmites$ $communis$ of 130 cm in length were 8.5% CP, 82.3 RFV and 70.2% IVDMD, while those of matured grasses of 220 cm in length were lower (10.2% CP, 65.1 RFV and 48.9% IVDMD), but this was a little more favorable than quality of rice straw. In Yeonggwang, feeding $Phragmites$ $communis$ was tried in a Hanwoo feed, but stopped due to low profitability. In conclusion, the overall quality of most native grasses including $Phragmites$ $communis$ in this survey was poor. Therefore, we recommend that $Phragmites$ $communis$ and native grasses should be harvested on June or July to obtain richer forage quality in forage values than rice straw.