• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2003년도 춘계 학술발표회 논문집
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• pp.7-14
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• 2003

The precious-meta] mineralization of epithermal type in the Korean Peninsula, which is spread over a broader range of ca. 110 to 60 Ma with a major population between 90 and 70 Ma, mainly occurred along the NE-trending major strike-slip fault systems (i.e., the Gongju and Gwangju ones) that commonly include volcano-tectonic depressions and calderas. The occurrence of epithermal mineralization during Late Cretaceous clearly indicates that the geologic setting of the Korean Peninsula changed to the favorable depth of ore formation with very shallow-crustal environments (〈1.0 kb) accompanied with gold-silver (-base-meta]) mineralization. Epithermal gold-silver deposits in Korea are primarily distinguished as sediment-dominant and volcanic-dominant basins by using criteria of varying alteration, ore and gangue mineralogy deposited by the interaction of different ore-forming fluids with host rocks and meteoric waters. These differences between the central and southern portions are causally linked to the tectonic evolution of the Peninsula during the Cretaceous time. In the Early Cretaceous, the sinistral strike-slip movements due to the oblique subduction of the Izanagi Plate resulted in the Gongju and Gwangju fault systems in the central portion of the Korean Peninsula, which was accompanied with a number of sediment-dominant basins formed along these faults. During the Late Cretaceous, the mode of convergence of the Izanagi Plate changed to northwesteward so that orthogonal convergence occurred with a calc-alkaline volcanism. As results, volcanic-dominant basins were developed in the southern portion of the Peninsula, accompanied with volcano-tectonic depressions and caldera-related fractures. The magmatism and related fractures during Late Cretaceous may play an important role in the formation of geothermal systems. Thus, such fault zones may be favorable environments for veining emplacement that is closely related to the precious-metal mineralization of epithermal type in the Korean Peninsula.

• 자원환경지질
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• 제44권2호
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• pp.109-122
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• 2011

국내 주요 몰리브덴 광상은 쥐라기 대보 조산운동기부터 후조산기인 백악기를 거쳐 제삼기까지 페그마이트형, 그라이센형, 스카른형, 반암형, 광맥형 광상과 같은 다양한 광상 유형으로 배태되고 있다. 장수 몰리브덴 광산은 쥐라기 티탄철석 계열 복운모 화강암과 관련된 페그마타이트 광상으로 배태되며, 광화 시기는 $159.6{\pm}4.5$ Ma이다. 금성 몰리브덴 광산은 분화가 매우 진행된 화강암과 관련된 스카른형/반암형 광상으로 큐폴라 광체의 광화시기는 96.5~107.5 Ma를 보이며, 황강리 광화대에 나타나는 후기 백악기 광화시기와 일치하고 있다. 연일 몰리브덴 광산은 반암형 광상으로 배태되고, 금음 몰리브덴 광산은 전단대를 따라 충진하는 석영 세맥으로 배태되며, 광화 시기는 각각 $58.4{\pm}1.6$ Ma과 $54.4{\pm}1.2$ Ma이다. 한국의 중생대 몰리브덴 광상은 조구조적 전화 특성에 따라 쥐라기에는 심부 화성활동을 반영한 페그마타이트질 맥상 광상으로 산출되는 반면, 백악기에는 천부 화성활동과 관련된 스카른형/반암형/광맥형 광상으로 배태된다. 특히 제삼기 몰리브덴 광화작용은 한반도 동해안을 따라 배태되는 제삼기 분지형성과 연계된 화성활동과 밀접한 관계를 보이고 있다.

• 한국환경농학회지
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• 제38권3호
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• pp.119-123
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• 2019

우리나라 노지 밭토양의 질소 비료 추천은 토양 유기물 범위에 따라 차등하여 추천한다. 토양 유기물 함량에 따른 질소 공급 가능량을 확인하기 위하여 노지 고추 재배 밭토양에서 작물 재배 전 토양을 채취하여 70일간 누적 질소 무기화량을 구하였다. 토양 유기물 함량(SOM)과 무기화 될 수 있는 토양 질소(SNM)의 관계식은 '$MSN(kg\;10a^{-1})=0.2933{\ast}SOM(g\;kg^{-1})+0.0897$ ($r^2=0.6224$, P<0.001)'이었다. 토양 유기물 범위별 평균 질소 무기화량은 각각 10.5, 26.6, 83.3, 105.6 mg kg-1으로 토양 유기물 함량이 많을수록 질소 무기화량도 많았으나, 같은 토양 유기물 범위에 속하는 토양이어도 질소 무기화량은 약 3~4.6배 차이가 있었다. 따라서 밭토양 질소 관리를 위해서는 토양 특성에 따른 질소 공급량 예측을 통해 질소 비료를 추천하는 것이 중요하다.

• 동굴
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• 제42권2호
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• pp.33-40
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• 1995

The Cheonbo gold mine is located approximately 8km northeast of Cheonan in southern part of Korean peninsula. The Cheonbo gold deposits are composed of parallel-filling quartz veins that are associated wi th the Cheonan granite which intruded the surrounding Precombrian metamorphic country rocks. Rb/Sr date of the granitic intrusion is 170${\pm}$0. 3m.y., suggesting a middle Jurassic age for gold mineralization.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2005년도 춘계 학술발표회 논문집
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• pp.275-278
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• 2005

• 자원환경지질
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• 제19권spc호
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• pp.193-206
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• 1986

A number of auriferous veins occur in the Precambrian metamorphic terrain from Chungju to Mugeug district. These gold (-silver) deposits consist mainly of the fissure-filling quartz veins intruding the Precambrian gneiss or schist and Jurassic or Cretaceous granite. These gold (-silver) deposits can be 'divided into two mineralization epochs, (a) gold-rich veins related to Daebo igneous activity, and (b) gold-silver veins related to Bulgugsa igneous activity. These two groups of ore deposits with different generation can be characterized by the mode of occurrence of ore vein and the ore mineral associations. The auriferous quartz veins of Taechang and Boryeon mines associated with late Jurassic igneous activity are massive in character, and show the simple mineral assemblages and low Ag/Au ratio in the ores, representing a single mineralization system. The ore minerals are predominantly quartz containing minor or trace amonts of pyrrhotite, sphalerite, galena, pyrite, chalcopyrite and electrum. Electrum is closely associated with pyrrhotite and has chemical compositions from 61.4 to 78.5 atomic % Au. Fluid inclusion data suggest that ore minerals were deposited at temperatures between 238 and $390^{\circ}C$ from $CO_2$-rich fluids. The gold and/or silver-bearing quartz veins of Geumwang mine related to middle Cretaceous igneous activity are characterized by the multistage history, diverse mineral assemblages with high Ag/Au ratio in the ores. The ores of Geumwang mine have two contrasting mineral assemblages (1) pyrite+galena+sphalerite+arsenopyrite+electrum+argentite, representing the higher gold mineralization, and (2) pyrite+chalcopyrite+ galena +sphalerite+ arsenopyrite+silver sulfosalts+ electrum+ native silver+argentite, representing the higher silver mineralization. Electrum is closely associated with pyrite and has chemical compositions from 11.2 to 49.9 atomic % Au. The depositional environment during the higher gold mineralization can be estimated as the range of both temperature and sulfur fugacity, T= $200{\sim}300^{\circ}C$, log f ($S_2$) = $10^{-10}{\sim}10^{-15}$. The higher silver mineralization may be interpreted to have formed a range of falling temperature ($150{\sim}200^{\circ}C$) and low sulfur fugacity($10^{-10}{\sim}10^{-15}$). These temperature data are consistent with homogenization temperatures of fluId inclusions in quartz. Thus, the gold veins related to the Daebo igneous activity may be formed by the environment of higher temperature and pressure than the gold-silver veins associated with the Bulgugsa igneous activity.

• 한국산림과학회지
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• 제84권2호
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• pp.198-206
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• 1995

이 연구는 루브라참나무림과 레시노사소나무림의 질소 무기화율이 개벌후 어떤 변화를 보이는지에 관하여 조사한 결과이다. 토양상층부 15cm에서의 질소 무기화율이 비닐주머니에 토양을 배양하는 방법을 이용하여 1991년과 1992년 임목 생장 기간 동안(5월-10월) 조사되었다. 두 임목 생장 기간 동안 추정된 참나무림의 질소 무기화율은 개벌 처리구 67kg/ha, 무처리구 30kg/ha였고, 소나무림은 개벌 처리구 27kg/ha, 무처리구 13kg/ha였다. 총 질소 무기화율은 항상 참나무림이 소나무림보다 높았다. 배양전과 한달 배양후 토양으로부터 질산태 질소는 소나무림의 개벌 처리구에서 검출된 반면(두임목 생장 기간동안 평균 질산화율 : 3.3kg/ha), 두 임분의 무처리구와 참나무림의 개벌 처리구에서는 거의 검출되지 않았다. 연구 결과들은 두 임분내 이용 가능한 질소량에 상당한 증가가 개벌후 발생하였으며, 낮은 질산화율은 이 임분들에 질소 보유를 위한 중요한 작용일 가능성을 시사한다.

• Advances in environmental research
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• 제1권4호
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• pp.289-304
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• 2012

Tris (2-methyl-1-aziridinyl) phosphine oxide (MAPO) is extremely poisonous and persistent in aqueous media. An efficient UV/nano$TiO_2$ process was employed for its mineralization in a high duty falling film photo-reactor based on an experimental design scheme that considers interactions between the main variables. The influencing variables and their range were determined with preliminary studies. The results show substrate mineralization to some extent under mild conditions of: T = $30^{\circ}C$, pH = 8.5, $[MAPO]_0=60\;mg\;L^{-1}$ and $[TiO_2]=110\;mg\;L^{-1}$. The relative importance of the influencing parameters were initial pH > temperature > $[MAPO]_0$ > [$TiO_2$]; while the interdependence of all the parameters was significant. Accordingly, a reduced quadratic expression was developed. Meanwhile, mineralization kinetic studies, based on chemical oxygen demand, revealed a power law model with order of 2.6 during process time until 150 min.

• The Korean Journal of Ecology
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• 제18권4호
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• pp.493-502
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• 1995

Nodulation phenology in relation to plant phenology, vertical distribution of nodul and root biomass in different soil, correlation between nodule and root size, and nitrogen mineralization around the rhizosphere by ion-exchange resin bag buried at 10 cm of soil were studied in Elaeagnus nmbellata (autumn-olive) stand, Korea. Nodulation appeared from spring to autumn and nodule phenology was coincided with the timing of root activity rather than that of foliation. Nodul size increased in proportion to the root size. In the sand dune with the lower root biomass, nodule appeared up to 80 cm deep in soil and the nodule biomass was 1,070 kg/ha, which was the highest value reported for several actinorhizal plants in the temperate regions. It is suggested that nodule distribution and production are mainly influenced by soil aeration among environmental factors. The higher ammonification or lower nitrification rate contrasted markedly with the earlier studies that reported lower ammonification or higher nitrification in actinorhizal plant soil. Nitrogen mineralization rate around the rhizosphere with root and nodule was characterized by higher nitrification rate than that in the control soil without root and nodule.

• BMB Reports
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• 제45권10호
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• pp.571-576
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• 2012

Radiotherapy is considered to cause detrimental effects on bone tissue eventually increasing bone loss and fracture risk. However, there is a great controversy on the real effects of irradiation itself on osteoblasts, and the mechanisms by which irradiation affects osteoblast differentiation and mineralization are not completely understood. We explored how X-ray radiation influences differentiation and bone-specific gene expression in mouse calvarial osteoblasts. Irradiation at 2 Gy not only increased differentiation and mineralization of the cells, but also upregulated the expression of alkaline phosphatase, type I collagen, osteopontin, and osteocalcin at early stages of differentiation. However, irradiation at higher doses (>2 Gy) did not stimulate osteoblast differentiation, rather it suppressed DNA synthesis by the cells without a toxic effect. Additional experiments suggested that transforming growth factor-beta 1 and runt-transcription factor 2 play important roles in irradiation- stimulated bone differentiation by acting as upstream regulators of bone-specific markers.