간행물
한국지구과학회지 KCI 등재 The Journal of The Korean Earth Science Society
- 발행기관 한국지구과학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1225-6692 (Print)2287-4518 (Online)
- 수록기간 1979 ~ 2024
- 주제분류 자연과학 > 지구과학 자연과학 분류의 다른 간행물
- 십진분류KDC 450DDC 550
권호리스트/논문검색
제25권 제1호 (2004년 1월) 6건
1.
2004.01
구독 인증기관 무료, 개인회원 유료
The clay minerals of thirty-four bottom sediments collected from the northwestern continental shelf of the East China Sea have been determined by X-ray diffraction analysis. The clay mineral distribution is mainly controlled by the sediment source and the dominant circulation pattern. The predominant clay mineral in our study area is illite comprising more-than 70% of whole clay fraction. The highest concentration of illite (〉72%) is found in the southeastern offshore parts beyond the reach of terrigenous input from the Cheju Island. It means that these illites are largely transported by the Kuroshio Current from the South China Sea. Smectite is highly concentrated in the northwest middle part and in the outer-shelf mud patch. It seems to be due to the high supply of smectite transported from China where the fine-grained sediments are discharged from the modern and ancient Huanghe River. The relatively high abundance of kaolinite is likely derived from the Changjiang River via Taiwan ·Warm Current. In contrast, the large amounts of chlorite and high chlorite/kaolinite ratios occur in the northwestern are, reflecting the transportation by the Huanghai Sea Coastal Current from the southern Yellow Sea.
4,000원
2.
2004.01
구독 인증기관 무료, 개인회원 유료
Recently, spatial data integration for geoscientific application has been regarded as an important task of various geoscientific applications of GIS. Although much research has been reported in the literature, quantitative assessment of the spatial interrelationship between input data layers and an integrated layer has not been considered fully and is in the development stage. Regarding this matter, we propose here, methodologies that account for the spatial interrelationship and spatial patterns in the spatial integration task, namely a multi-buffer zone analysis and a statistical analysis based on a contingency table. The main part of our work, the multi-buffer zone analysis, was addressed and applied to reveal the spatial pattern around geological source primitives and statistical analysis was performed to extract information for the assessment of an integrated layer. Mineral potential mapping using multi-source geoscience data sets from Ogdong in Korea was applied to illustrate application of this methodology.
4,300원
3.
2004.01
구독 인증기관 무료, 개인회원 유료
Laboratory experiments were conducted in order to find effects of the intermediate principal stress of σ2 on rock fractures and faults. Polyaxial tests were carried out under the most generalized compressive stress conditions, in which different magnitudes of the least and intermediate principal stresses σ3 and σ2 were maintained constant, and the maximum stress σ1, was increased to failure. Two crystalline rocks (Westerly granite and KTB amphibolite) exhibited similar mechanical behavior, much of which is neglected in conventional triaxial compression tests in which σ2 = σ3. Compressive rock failure took the form of a main shear fracture, or fault, steeply dipping in σ3 direction with its strike aligned with σ2 direction. Rock strength rose significantly with the magnitude of σ2, suggesting that the commonly used Mohr-type failure criteria, which ignore the σ2 effect, predict only the lower limit of rock strength for a given σ3 level. The true triaxial failure criterion for each of the crystalline rocks can be expressed as the octahedral shear stress at failure as a function of the mean normal stress acting on the fault plane. It is found that the onset of dilatancy increases considerably for higher σ2. Thus, σ2 extends the elastic range for a given σ3 and, hence, retards the onset of the failure process. SEM inspection of the micromechanics leading to specimen failure showed a multitude of stress-induced microcracks localized on both sides of the through-going fault. Microcracks gradually align themselves with the σ1-σ2 plane as the magnitude of σ2 is raised.
4,000원
4.
2004.01
구독 인증기관 무료, 개인회원 유료
Some fine specimens of Annulariopsis bunkeiensis were collected from two fossil sites of the Amisan Formation of Nampo Group distributed in the Jogaegol, Boryeng City, Chungnam Province. According to our detailed study from our new material, the leaves of A. bunkeiensis are not mucronate, but emarginate at their apices. Accordingly, we revised the diagnostic characters given by Kimura and Kim (1988) mainly in regard to the leaf apex.
4,000원
5.
2004.01
구독 인증기관 무료, 개인회원 유료
In the FMAS system the effect of iron on alumina solubility in orthopyroxene has been determined by experiments with crystalline starting mixtures of garnet and orthopyroxene of known initial compositions at 20 kb, 975˚C and 25 kb, 1,200˚C. These data have been modeled to develop a thermodynamic method for the calculation of Al2O3 in orthopyroxene as a function of P, T and composition. The direct application of the alumina solubility data in the MAS system to natural assemblages could lead to significant overestimation of pressure, probably by about 5kb for the relatively common garnet-lherzolites with abot 25 mol per cent Ca + Fe2+ in garnet and about 1 wt. per cent Al2O3 in orthopyroxene since the effect of Fe is similar to that of Ca and Cr3+in reducing the alumina solubility in orthopyroxene in equilibrum with garnet relative to that in the MAS system.
4,000원
6.
2004.01
구독 인증기관 무료, 개인회원 유료
The light element candidates such as S, O, Si, and K are discussed for the reasonable compositions in the earth's core since the available data show density difference from pure iron core. These candidates are favored by the some evidences such as depletion in the crust and mantle, and lower eutectic temperature of Fe-FeS melt for sulfur. FeO phase for oxygen, lighter mass than sulfur and solubility in metallic phases for silicon, and partitioning in Fe-FeS melt for potassium. However, other problems such as short experimental data, initial compositions of these elements, and oxidation state during the formation of the earth should be solved simultaneously to confirm these light elements.
3,000원
