• Radiation Oncology Journal
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• v.15 no.2
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• pp.105-111
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• 1997

group($22\%\;vs.\;38\%$, p=0.24). The 5YSRs of 21 patients of primary tumor extension to adjacent sites and the other 13 patients of tonsillar proper site were $28\%\;and\;38\%$, respectively but the difference was not significant statistically(p=0.52) There was a statistically significant difference in 5YSRs between the groups of the Patients who received radiotherapy in less than 61days vs more than 60days($60\%\;vs.\;18\%$, p=0.027). All living Patients without any tumor progression(n=11) had suffered from serious late sequelae such as xerostomia, edentia, dental caries and one patient had the osteoradionecrosis of mandible. On univariate analysis. the duration of radiotherapy and T-stage were the significant prognostic factors affecting 5YSR. On multivariate analysis, also the duration of radiotherapy was the only significant Prognostic factor(p=0.01). Conclusion : There was no survival difference between the radiotherapy alone and with neoadiuvant chemothe groups. Although it was a retrospective study, the role of conventional radiotherapy alone could be effective as the local treatment modality only for the early stage of tonsillar carcinomas. But for the purpose of more improved survivals and better quality of lives of living patients, other altered fractionation such as hyperfractionated radiotherapy with shorter treatment time and smaller fraction size rather than conventional radiotherapy might be beneficial and these prospective studies are needed.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.397-407
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• 2022

Mineralogical analysis of the bedrock of the Gobi Desert in southern Mongolia, the source of Asian dust, was conducted to trace the geological origin of the constituent minerals of Asian dust. The bedrock of the source of Asian dust consists of Paleozoic volcanics and volcaniclastic sedimentary rocks, Paleozoic granitic rocks, and Mesozoic sedimentary rocks. Paleozoic volcanics and volcaniclastic sediments lithified compactly, underwent greenschist metamorphism, and deformed to form mountain ranges. Mesozoic sedimentary rocks fill the basin between the mountain ranges of Paleozoic strata. In comparison to Paleozoic volcanic and sedimentary rocks, Mesozoic sedimentary rocks have lower contents of chlorite and plagioclase, but high contents of clay minerals including interstratified illite-smectite, smectite, and kaolinite. Paleozoic granites characteristically contain amphibole and biotite. Compared with the mineral composition of bedrock in source, Asian dust is a mixture of detrital particles originating from Paleozoic and Mesozoic bedrocks. However, the mineral composition of Mesozoic sedimentary rocks is closer to that of Asian dust. Less lithified Mesozoic sedimentary rocks easily disintegrated to form silty soils which are deflated to form Asian dust.

• Journal of the Mineralogical Society of Korea
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• v.8 no.2
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• pp.91-107
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• 1995

충남 예산-공주-청양지역의 대흥, 평안, 신양(청당)광산에서 산출되는 녹니석에 관하여 화학적 및 성인적 연구를 하였다. 이들 광상은 초염기성암기원의 사문암이 열수변질작용을 받아 생성되었다. 활석 광석의 주 구성 광물은 활석, 녹니석, 금운모, 각섬석류, 사문석, 탄산염광물 등이고 이밖에 감람석, 휘석류, 크롬철석, 스멕타이트, 녹니석/스멕타이트의 혼합층상광물들과 같은 팽윤성 광물들이 소량 산출된다. 이 중 감람석과 크롬철석은 광상의 초염기성암 기원을 지시하는 중요한 광물이다.녹니석은 활석 광석의 불순 광물 중 가장 많은 양을 차지하는 광물이다. 이들 녹니석은 성인적으로 활석과 밀접하게 연관된 녹니석과 그렇지 않은 녹니석의 두 가지 뚜렷한 타입으로 나뉘어지며 이들은 화학적으로 명확한 차이를 보인다. 전자의 녹니석은 Mg/(Mg+Fe)비가 높으며 매우 일정한 범위의 Mg/(Mg+Fe)qkl (0.784∼0.951/산소수 14 기준)를 보여주고, 높은 8면체 치환양 (0.892 (-0.200∼0.692)/산소수 14, 이상적인 클리노클로어/차모사이트 성분 기준)과 넓은 범위의 Al 함량 변화 (2.975 (1.085∼3.160)/산소수 14 기준), 높은 Cr, Ni 함량을 갖는다. 이들은 매우 제한되고 높은 Mg/(Mg+Fe)비를 갖는 환경에서 생성되었으며 따라서,활석과 밀접하게 연관된 녹니석은 생성시, 주변암에 둘러싸여 있는, 초염기성암 기원의 사문암에 의해 주로영향을 받았다. 후자의 녹니석은 전자의 녹니석에 비하여 Fe 함량이 더 놓으며 광범한 범위의 Mg/(Mg+Fe)비 (0.378∼0.852/산소수 14 기준)를 보여주고, 더 적은 범위의 8면체 치환양 (0.560 (-0.035∼0.525)/산소수 14, 이상적인 클리오클로어/차모사이트 성분 기준)과, 전반적으로는 더 높은 값을 가지면서 더 좁은 범위의 Al 함량 변화 (1.491 (1.468∼2.959)/산소수 14 기준)를 보여주며, 낮은 Cr, Ni 함량을 갖는다. 이들은 낮은 Mg/(Mg+Fe)비를 갖고 전자에 비해 Al이 풍부한 환경에서 생성되었으며, 따라서 활석과 연관되지 않은 녹니석은 생성시 광체와 인접한 화강아질 편마암에 의해 주로영향을 받았을 것으로 생각된다. 녹니석의 이러한 2가지 화학조성상의 경향은 녹니석과 공존하는 운모류나 각섬석류들의 화학분석결과와도 잘 일치한다. 이러한 결과는 이 지역의 활석 광상이 초염기성암 기원의 사문암이 열수변질작용을 받아 생성되었음을 명확하게 지시하며, 따라서 활석 광석내에 존재하는 녹니석은 활석의 근원 광물로서 녹니석편암 및 녹니석 편마암 매의 녹니석이 활석화되고 남은 잔존광물이 아니라, 주변암에 의해 성분상의 영향을 받은 열수와 사문암과의 변질교대작용에 의한 활석화과정 중에 주로 생성된 것으로 추정된다. 이러한 결과는 연구지역의 활석광상이 초염기성암의 사문암화 작용과 활석화 작용의 두 가지 변질작용에 의해 형성되어졌음을 알려준다.

• Economic and Environmental Geology
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• v.44 no.5
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• pp.373-386
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• 2011

Geochemical study was performed on black slates and interbedded U-bearing coaly slates in Deokpyeongri area, the representative uranium mineralized district of the Ogcheon Metamorphic Belt, to discuss the genetic environments of the uranium deposit. REE concentration (254 ppm) of the black slates is higher than that (169 ppm) of the coaly slates and NASC-normalized REE patterns of the coaly slates show remarkable positive Eu anomaly. l11e redox-sensitive trace elements such as V, Cr, Co, Ni, Mo and U in the coaly slates are highly enriched compared to the black slates, especially for V of 24 times, Mo of 62 times, and U of 60 times. In additions, Pd and Pt are also enriched in the coaly slates. Positive Eu anomaly and the noticeable enrichment of the elements listed above compared to those of NASC indicate that those elements were not derived from common seawater but deposited under high temperature and reducing environment of submarine hydrothermal activities. Wide compositional ranges of major elements ($SiO_2/Al_2O_3$: 3.98~11.88, $Al_2O_3/Na_2O$: 25.6~139.06, $K_2O/Na_2O$: 6.80~46.85) also suggest that the source rocks of the sediments are mixtures of sedimentary rocks and igneous rocks. Higher sulfur contents in the coaly slates, 2.6 wt.%, than those in the black slates, 0.6 wt.% also indicates that the former was influenced by hydrothermal activities containing much sulfur. These geochemical characteristics are similar to the genetic environments of South China type PGE deposits (Mo-Ni-Zn-PGE) which is geotectonically correlated with the Ogcheon Metamorphic Belt and is known as sedimentary-exhalative deposits. In conclusions, the uranium and other metallic elements mineralization seems to have occurred in the sedimentary basin that was affected by submarine hydrothermal activities and rich in organic materials under oxygen-poor environments as well.

• The Korean Journal of Petroleum Geology
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• v.12 no.1
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• pp.27-33
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• 2006

The possibility of oil reserve has been conformed because the oil has been produced by 450 barrel per day in the West Korea Bay basin of the North Korea. There is also possibility of giant oil reserve since it is geographically close to one of the biggest oil fields of Bohai Basin, China. Based on the on-going oil exploration and the present condition of investment, the areas of ongoing oil exploration are three: West Korea Bay B&C prospect explored by Swedish Taurus, the north of West Korea Bay and Anju basin explored by Canadian SOCO, and East Korea Bay explored by Australian Beach Petroleum. However, there is little or no possibility of oil reserve in the rest sea areas of three. Even though oil reserves were discovered in the some parts of land areas such as Kilju and Myungcheon, it was presumed to have no economical efficiency. Geology in West Korea Bay off the North Korea is similar to that in Bohai Bay off China. The basement consists of thick carbonate rock of the Late Proterozoic and Early Paleozoic overlain by Mesozoic ($6,000{\sim}10,000\;m$) and Cenozoic ($4,000{\sim}5,000\;m$) units. Source rocks are Jurassic black shale (3,000 m or more), Cretaceous black shale ($1,000{\sim}2,000\;m$), and pre-Mesozoic carbonates (several thousand meters). Reservoir rocks are Mesozoic-Cenozoic sandstone with high porosity and pre-Mesozoic fractured carbonate rocks. Petroleum raps are of the anticline, fault sealed, buried hill, and stratigraphic types. It absolutely needs to take up a positive attitude, the activation of ocean science and technology exchange, and the joint research and development of modern MT (Marine Technology) considering the state of establishing new international ocean order forcing on building up 200 nautical mile EEZ (exclusive economic zone) among coastal nations. Both South and North Koreas should extend the ocean jurisdiction and contiguity, and MT development dealing with the same sea areas. It is more urgent problem to find a way to have the North Korea participated in, and then to develop ocean management and ocean industry individually.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.313-331
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• 2022

Natural or native abiotic molecular hydrogen (H₂) is a major component in natural gas, however yet its importance in the global energy sector's usage as clean and renewable energy is underestimated. Here we review the occurrence and geological settings of native hydrogen to demonstrate the much widesprease H₂ occurrence in nature by comparison with previous estimations. Three main types of source rocks have been identified: (1) ultramafic rocks; (2) cratons comprising iron (Fe²⁺)-rich rocks; and (3) uranium-rich rocks. The rocks are closely associated with Precambrian crystalline basement and serpentinized ultramafic rocks from ophiolite and peridotite either at mid-ocean ridges or within continental margin(Zgonnik, 2020). Inorganic geological processes producing H₂ in the source rocks include (a) the reduction of water during the oxidation of Fe²⁺ in minerals (e.g., olivine), (b) water splitting due to radioactive decay, (c) degassing of magma at low pressure, and (d) the reaction of water with surface radicals during mechanical breaking (e.g., fault) of silicate rocks. Native hydrogen are found as a free gas (51%), fluid inclusions in various rock types (29%), and dissolved gas in underground water (20%) (Zgonnik, 2020). Although research on H₂ has not yet been carried out in Korea, the potential H₂ reservoirs in the Gyeongsang Basin are highly probable based on geological and geochemical characteristics including occurrence of ultramafic rocks, inter-bedded basaltic layers and iron-copper deposits within thick sedimentary basin and igneous activities at an active continental margin during the Permian-Paleogene. The native hydrogen is expected to be clean and renewable energy source in the near future. Therefore it is clear that the origin and exploration of the native hydrogen, not yet been revealed by an integrated studies of rock-fluid interaction studies, are a field of special interest, regardless of the presence of economic native hydrogen reservoirs in Korea.

• The Korean Journal of Petroleum Geology
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• v.7 no.1_2 s.8
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• pp.28-34
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• 1999

The Cretaceous Poongam sedimentary Basin in Kangwon-do, Korea consists alluvial deposits of conglomerates, sandstones, mudstones or siltstones, and volcaniclastics. The Poongam Basin was formed as a fault margin sag or a transpressional basin developed along a strike-slip fault zone, and received huge amount of clastic sediments from the adjacent fault-scaip. It formed an aggrading alluvial fan system and a volcaniclast-supplied marginal lake environment, while tectonic activity and volcanism attenuated toward the end of basin formation. Following the Folk's classification, the sandstones of the Poongam Basin are identified as lithic wackes or feldspathic wackes. The areal and sequential variation of the mineral composition in the sandstones is not distinct. The results of K-Ar age dating from the intruding andesites, volcaniclastics and volcanic fragments in sedimentary rocks show a range of 70 Ma to 84 Ma. It suggests that volcarism occurred sequentially within a relatively short period as the pre-, syn-, and post-depositional events. It was the short period in the late Cretaceous that the basin had evolved i.e., the basin formation, the sediment input and fill, and the , intrusion and extrusion of volcanic rocks occurred. The Poongam sedimentary sequence is a typical tectonic-controlled coarse sedimentary facies which is texturally immature.

• Journal of the Korean earth science society
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• v.42 no.6
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• pp.646-661
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• 2021

The Zagros fold-thrust belt formed from the collision of the Arabian and Eurasian plates during Cenozoic periods and extends for 2,000 km, from Turkey to the Hormuz Strait, in the northeast-southwest direction. Anticline traps in the front of the Zagros thrust fold hold approximately 8% of the world's petroleum reserves. Middle Cretaceous to Early Miocene petroleum systems of the belt have the largest original oil in place (OOIP). The oil is expelled from Kazhdumi and Pabdeh source rocks, and accumulated in the Asmari and Bangestan (including Sarvak and Ilam formations) reservoir rocks covered by the evaporitic Gachsaran and the marly Gurpi formations. The hydrocarbons trapped in the Asmari and Sarvak reservoirs are mainly charged (more than 90%) by the Kazhdumi Formation whereas the rest are charged by the Pabdeh Formation. In the Dezful Embayment, all the large high-relief anticlines have been drilled into, except in the Asmari, Sarvak and Khami formations, where a few anticlines of smaller size and deeper strata remain unexplored. Therefore, the exploration potential of these regions strengthens our understanding of the Zagros fold-thrust belt's petroleum system.

• Journal of the Mineralogical Society of Korea
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• v.3 no.2
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• pp.79-88
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• 1990

고령토의 조직과 산출상태의 관찰결과 산화철 광물을 침전시킨 철의 주요 근원은 모암인 회장암에 함유된 각섬석과 녹니석이다. X선 회절 분석결과 침철석은 녹니석이 버미큘 라이트로 변질되고 각섬석이 용해되기 시작하는 하부 백색 광석에서 우세하며, 적철석은 각섬석, 녹니석 및 버미큘라이트가 심한 용탈작용을 받는 상부 적갈색 광석이나 열 개에서 침철석과 함께 산출된다. 침철석 및 적철석내 Fe에 대한 Al의 치환량은 각각 6~26 mol% 및 5~8mol%이며 이 두 값 사이에는 비례 관계가 있다. 회절선폭의 크기로부터 계산된 침철석과 적철석의 평균 입자크기는 340$\AA$ 이하이며 침철석은 약간의 침상을 보이는 반면 적철석은 탁상이다. 전자현미경 관찰에 의하면 버미큘라이트와 수반되는 침철석은 침상 또는 성상이나 적갈색 광석에서는 그러한 특징이 작다. 적철석은 육각 또는 원형을 보이나 상부 적갈색 광석에서는 보다 불？칙한 모양이다. 적철석과 침철석의 광물학적 특성을 합성실험에서 보고된 결과들과 비교하여 성인적 측면에서 논의되었다. 이 지역에서는 침철석과 적철석의 생성에 적합한 기후조건들이 중첩된 것으로 생각된다.

• The Journal of the Petrological Society of Korea
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• v.12 no.1
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• pp.32-52
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• 2003

The Mt. Baegyang in Busan, composed of sedimentary basement rocks (Icheonri Formation), andesite (lava), andesitic pyroclastic rocks, fallout tuff and tuffaceous sedimentary rocks, rhyolitic pyroclastic rocks, intrusive rocks (granite-porphyry, felsite, and biotite-granite) of Cretaceous age in ascending order. The volcanic rocks show a section of composite volcano which comprised alternation of andesitic lava and pyroclasitc rocks, rhyolitic pyrocalstic rocks (tuff breccia, lapilli tuff, fine tuff) from the lower to the upper strata. From the major element chemical analysis, the volcanic and intrusive rocks belong to calc-alkaline rock series. The trace element composition and REE patterns of volcanic and plutonic rocks, which are characterized by a high LILE/HFSE ratio and enrichments in LREE, suggest that they are typical of continental margin arc calc-alkaline rocks produced in the subduction environment. Primary basaltic magma might have been derived from partial melting of mantle wedge in the upper mantle under destructive plate margin. Crystallization differentiation of the basaltic magma would have produced the calc-alkaline andesitic magma. And the felsic rhyolitic magma seems to have been evolved from andesitic magma with crystallization differentiation of plagioclase, pyroxene, and hornblende.