• Journal of the Korean earth science society
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• v.38 no.7
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• pp.552-560
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• 2017

This study investigates the development process of Mt. Deok on Bigeum Island, Shinan, on the basis of geomorphological and geological analyses. K-Ar dating was carried out on two samples of the acidic lapilli tuff developed in the study area, and the obtained K-Ar ages are $70.4{\pm}1.4$ and $76.9{\pm}1.5Ma$, which correspond to the Late Cretaceous (Campanian). Mt. Deok is surrounded by rock cliff, and various weathering microtopographic features, such as tafoni, tor and gnamma, are developed. Tafoni with diverse morphologic types is the most dominant feature, indicative of intense salt weathering. Geological characteristics such as porous tuff and joint have played an important role in the development of tafoni and rock cliff. Geomorphology and geology of Mt. Deok reflect paleoenvironmental change and interaction between human and nature in the coastal area.

• Journal of Plant Biology
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• v.36 no.4
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• pp.357-362
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• 1993

To elucidate the origin of secondary growth in the rhizome of B. ternaturn, the developmental changes of vascular cambium was observed in ultrastructural features. The vascular cambium was gradually differentiated from procambium as in seed plants, but the cambial activity did not persist very long so that the cambial cells became a dormant state like fossil cryptogams. Dense cytoplasm of procambial cells became progressively sparse during the growth, and the tiny vesicles were fused to form numerous small vacuoles and then a few large vacuoles. These gradual changes and the occurrence of storage materials which was associated with the developmental stages might support the progressive differentiation of the cambial cells. In addition, the cessation of cambial activity could be indicated by the facts that late vascular cambial cells accumulate large lipid bodies and show very small peripheral cytoplasm and unlikely thickened cell wall, compared to other meristematic cells. Therefore. the vascular cambium showed the characteristics of both seed plants and fossil cryptogams from the view point of cambial ontogeny and activity.tivity.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.767-785
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• 2021

World-class magnesite deposits are developed in the Dashiqiao mineralized district of the Jiao-Liao-Ji Belt in China. This belt extends to the northern side of the Korean Peninsula and hosts major magnesite deposits in the Dancheon region of North Korea. Magnesite ores from the Pailou deposits in the Dashiqiao district is classified into pure magnetite, chlorite-magnetite, chlorite-talc-magnetite, and dolomite groups depending on the constituent minerals. According to the result of petrographic study, magnesite was formed by the alteration of dolomite, and, talc, chlorite, and apatite were produced as late-stage alteration minerals that replaced the magnesite. Fluid inclusions observed in magnesite are a liquid-type inclusion, with a homogenization temperature of 121-250 ℃ and a salinity of 1.7-22.4 wt% NaCl equiv. The chlorite geothermometer, indicating the temperature of hydrothermal alteration, is 137~293 ℃, slightly higher than the homogenization temperature of fluid inclusions, and the pressure is calculated to be less than 3.2 kb. For magnesite mineralization in the study area, the initially formed-dolomite was subjected to replacement by Mg-rich fluid to form a magnesite ore body, and then it was enriched through regional metamorphism and hydrothermal alteration. It seems that altered minerals such as talc were crystallized by Si and Al-rich late-stage hydrothermal fluids. These results are similar to the genetic environments of the Daeheung deposit, a representative magnesite deposit in North Korea, and it is believed that the two deposits went through a similar geological and ore genetic process of magnesite mineralization.

• Economic and Environmental Geology
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• v.55 no.1
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• pp.77-95
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• 2022

The Gonamsan gabbroic complex in the Pocheon area, northwestern region of South Korea consists of a variety types of gabbroic rocks and associated Fe-Ti oxide deposits caused by magmatic differentiation. Post-magmatic intrusions (i.e., gabbroic pegmatite and pyroxene-apatite-zircon rocks) partly intruded into the gabbroic rocks. The gabbroic pegmatite occurs in monzodiorite and oxide gabbro of the complex, intimately and spatially associated with high-grade lenticular Fe-Ti oxide mineralization. The pegmatite can be subdivided into plagioclase-amphibole and pyroxene-olivine pegmatite, in which the contact surface is sharp. The plagioclase-amphibole pegmatite comprises plagioclase and amphibole, with lesser amount of pyroxene, ilmenite, sphene, apatite, and biotite. The pegmatite shows plagioclase-amphibole intergranular texture, in which the open space formed by large plagioclase laths (An_2-26Ab_72-98Or_0-2) are infilled by amphibole. The pyroxene-olivine pegmatite is dark gray to black in color and also contains magnetite, ilmenite, spinel, apatite, and calcite as a minor component. The pyroxene (En_35-36Fs_8-9Wo₅₅) and olivine (Fo_84-85Fa_15-16) partly show a poikilitic texture defined by smaller euhedral olivine enclosed by coarser clinopyroxene. Fe-Ti oxide minerals consist mainly of magnetite and ilmenite that are found interstitially to earlier formed silicates. Subsequently, they are encompassed by reaction rim (almost of amphibole and biotite) along the boundary with surrounding silicate minerals. Under the microscope, magnetite contains a lot of oxyexsolved ilmenite (trellis type) and spinel, and thereby is weakly enriched in magnetite-compatible elements such as Ti, Al, Mg, and V. The structure and textures at the contact zone as well as mineralogical disequilibrium between gabbroic pegmatite and the host gabbroic rocks suggest that the pegmatite may form as a result of accumulation from Fe-rich melt (or liquid) that occurred somewhere rather than in situ form from the host gabbroic rock during the magmatic differentiation. Consequently, the preliminary study suggests that further study on the post-magmatic activities can not only help us improve our understanding on magmatic fractionation but also provide critical information on Fe-Ti oxide mineralization in gabbroic rocks resulting from the magmatic differentiation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.4
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• pp.323-330
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• 2023

The skin's barrier structure is formed through the differentiation process of epidermal keratinocytes. It consists of corneocytes that are composed of keratin proteins and lipids that fill the spaces between them. During this process, the lipids such as phospholipid that made up the membrane of the basal layer cells of the epidermis are decomposed and replaced with newly synthesized components like ceramide. In this study, the effect of ginsenoside Rg3 components on the packing of the intercellular lipid structure of the skin barrier and the barrier function was confirmed. To confirm this, Rg3 components were treated during the differentiation process of 3D epidermal cells. The FT-IR and TEWL analysis on 3D epidermis showed an enhancement in the orthorhombic lipid packing and an improvement in barrier function. Additionally, in HaCaT cells, an increase in the expression of EVOL1 and EVOL4, which synthesize long-chain lipids, was detected, along with a decrease in CERS6, which synthesizes short-chain ceramide, and an increase in ACER6, which decomposes ceramide using phytosphingosine. This suggests the possibility that Rg3 affects lipid synthesis during the epidermal differentiation process, resulting in changes in barrier function.

• Economic and Environmental Geology
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• v.34 no.5
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• pp.437-446
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• 2001

Zoned epidotes formed by the propylitic alteration of the Bobae sericite deposit in western Pusan show complex compositional zoning patterns, such as multiple growth zoning, oscillatory zoning, patchy zoning and irregular zoning. The complex zoned epidote, in general, shows AI-rich cores and Fe-rich rims. Pistacite component (Ps) in the epidote ranges from 18.5 to 74.3 mot.%. Remnant textures in multiple growth zoning indicate that the earlier zone was partially resorbed prior to growth of later one. Multiple growth zoning and oscillatory zoning suggest that hydrothermal system underwent rapid changes and fluctuations in fluid chemistry, redox condition, or temperature.

• Economic and Environmental Geology
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• v.17 no.4
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• pp.259-272
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• 1984

Fluid inclusion and stable isotope studies on the Sangdong tungsten skarn have led to a conclusion that the mineralizing fluids might be derived from a magma, which was inferred within 1km below the present Sangdong ore deposit. Mineral assemblages of the skarns appear to have formed under the equilibrium conditions as the fluids flow outward from a central fluid column, in which the quatz-mica occurs dominantly. A characteristic skarn showing mineralogical zonation by repeated over-prints. The quartz-mica zone at the central part of the Sangdong skarns shows the final stage of protracted fluid evolution. Thermodynamic conclusion based on simplified chemical compositions of major components may express quantitatively the conditions of the skarn formation by using diagrams.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.06a
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• pp.176-181
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• 2004

남${\cdot}$북 Bismarck 판은 호주판과 태평양 판 사이의 복잡한 판구조를 보이는 지역에 위치한다. 남${\cdot}$북 Bismarck 판 내부에서는 판구조 활동이 활발하게 일어나 지진의 발생빈도가 높고 활성 및 비활성화산이 많이 존재한다. 한국해양연구원은 Bismarck 해의 서부지역과 동 Manus 분지에서 판 경계부의 구조 및 열수구조의 밝히기 위하여 탄성파 탐사를 수행하였다. 탐사결과에 의하면 남${\cdot}$북 Bismarck 판의 경계부에는 주향이동단층대가 발달되어 있으며 이는 판의 경계를 나타내고 있다. PACMANUS 열수하부에는 돔 형태의 구조가 존재하며 이는 마그마 또는 이의 분화과정에서 형성된 지질학적인 구조로 추정된다.

• Journal of Space Technology and Applications
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• v.1 no.1
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• pp.64-75
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• 2021

On the moon as well as the earth, one of the easiest ways to understand geological formation history of any region is to observe the stratigraphy if it is available, the order in which the strata build up. By analyzing stratigraphy, it is possible to infer what geological events have occurred in the past. Mare Nubium also has an unique normal fault called Rupes Recta that shows stratigraphy. However, a rover moving with wheels is incompetent to explore the cliff since the Rupes Recta has an inclination of 10° - 30°. Therefore, a quadruped walking robot must be employed for stable expedition. To exploration a fault with a four-legged walking robot, it is necessary to design an expedition route by taking account of whether the stratigraphy is well displayed, whether the slope of the terrain is moderate, and whether there are obstacles and rough texture in the terrain based on the remote sensing data from the previous lunar missions. For the payloads required for fault surface exploration we propose an optical camera to grasp the actual appearance, a spectrometer to analyze the composition, and a drill to obtain samples that are not exposed outward.

• Proceedings of the KSEG Conference
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• 2002.04a
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• pp.173-182
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• 2002

단층이동자료를 이용하여 지구조 사건을 분별하고 단층의 운동시기 및 한반도 주변지구조체계와 비교하여 양산단층의 진화과정을 해석하였다. 양산단층은 팔레오세 때 단층형성이 시작되었고 그 후 NW-SE 신장 사건에 의해 우수주향이동을 했다. 우수주향이동은 장구한 시간동안 진행되어 마이오세 초에 확장축이 바뀜에 따라 약간의 변화가 있지만 우수운동은 지속되었다. 마이오세 말에 양산단층은 좌수이동으로 변하여 운동하게 되며, 마이오세 말 혹은 플라이스토세 초에 와서 양산단층은 N-S 방향의 최대 수평압축응력을 받게 된다. 이후 플라이스토세를 전후해서 E-W 방향의 최대수평압축응력에 의해 양산단층은 다시 우수이동을 한다. 이와 같이 양산단층은 한번의 운동으로 발달된 단층이 아니라 서로 다른 응력체계 하에서 다중변형을 받아 현재의 모습으로 진화되었다고 판단된다.