• 지질공학
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• 제20권4호
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• pp.461-465
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• 2010

암석에서의 풍화 및 투수성은 방사성폐기물 지하동굴처분 및 암반구조물의 안정성 확보 및 장기적 관리측면에서 매우 중요한 역할을 한다. 이들 암석의 풍화 및 투수성은 암석의 내 구조 특성에 따라 크게 영향을 받는다. 즉 암석 내부의 공극, 미소 크랙 등의 양적 정도에 의해 풍화가 빨리 진행되기도 한다. 또한 암석 내부구조의 양적 평가는 그 암석의 풍화 정도를 정량적으로 평가할 수 있는 수단이 되기도 한다. 따라서 암석의 내부구조를 3치원적으로 정확하게 파악한다는 것은 암반구조물의 장기적 관리 측면에서 매우 중요하다고 하겠다. 이 연구는 국내 신선한 화강암과 풍화된 화강암을 대상으로 X선 CT촬영을 실시하여 3차원으로 공극의 분포를 분석하였다. 분석 결과는 암석 내부의 공극의 분포와 공극률을 잘 표현하고 있다.

• 한국지형학회지
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• 제25권4호
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• pp.21-35
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• 2018

The distribution and size of sandy beaches along eastern Korea has a close relationship with the presence of granite rocks. In general, elongated and wide beaches with abundant sands are likely to develop along the coasts where granitic basic rocks comprise the dominant geology or where a large amount of sands are supplied by streams from inland granitic rocks. Small sandy beaches, in contrast, appear in non-granitic rocks (i.e., under sedimentary and/or metamorphic geology). Hence, large beaches are observed continuously along the shore of Gangwon-do, of which coasts consist predominantly of granitic geology. Such continuity declines from Samcheok city to Pohang city. The rock of Gyeonbuk-do is commonly known as sedimentary, deposited between the late Triassic and the early Tertiary Periods. Because few sands are supplied from the upstream areas, sandy beaches unlikely develop along the coasts of the province, only showing a sporadic, discontinuous distribution under Bulguksa granite, granitic gneiss, and some volcanic rocks. Erosion was rarely observed in the beaches where granitic rocks are distributed, whereas merely five beaches seemed to have undergone some level of erosion in non-granitic regions. This is presumably because a larger amount of sands than that which had been eroded away was replenished in areas under granitic geology, while under non-granitic geology having a deficit in sands, no large sandy beaches had formed at first.

• 자원환경지질
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• 제24권4호
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• pp.393-398
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• 1991

The Buyeo-Cheongyang area, in the south-western area of Gyeonggi massif, comprises Precambrian and Mesozoic metamorphic and sedimentary rocks. The original rock of metamorphic rocks was studied by geochemical examination and statistical analyses of the trace elements in the gneisses, schists, shale and granitic rocks. Average abundance of Cu,Cr,Pb,Ni,Co,Mn,Li and Zn elements from gneisses have similar to those from shale and schists. However the gneisses have higher Cr,Ni,Co,Mn,Li abundance than those from the granite. Abundance range and frequency distribution of the trace elements in the gneiss show a marked trend sedimentary origin, that is, standard deviation have far the higer than that of igneous origin. Also it is wide dispersion and irregularly distribution. For that reason, this gneiss is regard as sedimentary original rocks with schists.

• 암석학회지
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• 제27권2호
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• pp.85-96
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• 2018

옥천변성대의 북서부에 위치하는 충주 어래산지역은 신원생대 계명산층과 중생대 화성암류가 분포하고, 계명산층 내에 희토류 광화대가 보고된 바가 있다. 이 논문에서는 희토류 광체의 기원암과 그 분포 및 특성을 파악하기 위해 암상구분에 의한 상세한 지질도를 작성하고, 구성암류의 방사능 값을 측정하였다. 그 결과 신원생대 계명산층의 주요 암상은 변성이질암, 화강암질편마암, 함철규암, 변성심성산성암(호상형, 세립형, 함염기성형, 조립형), 변성화산산성암 등으로 구성되어 있고, 이를 관입하는 중생대 화성암류는 페그마타이트, 흑운모화강암, 반려암, 섬록암, 염기성 암맥 등으로 구분된다. 계명산층의 구성암류는 주로 동북동 방향의 대상분포를 보이고, 함염기성형 변성심성산성암의 분포는 이전 연구자에 의해 작성된 희토류 광체의 분포와 매우 유사하다. 그리고 중생대 흑운모화강암은 기존 연구결과와 달리 어래산지역의 전역에 광범위하게 분포한다. 또한 함염기성형 변성심성산성암은 연구지역의 구성암류 중에 가장 높은 방사능 값의 범위(852~1217 cps)와 평균값(1039 cps)을 보인다. 노두별 방사능 값의 최대 밀도를 보이는 분포영역은 또한 함염기성형 변성심성산성암의 분포 영역과 일치한다. 이는 함염기성형 변성심성산성암이 희토류 광체의 기원암일 가능성을 지시한다.

• 지구물리와물리탐사
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• 제7권1호
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• pp.56-61
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• 2004

In order to image the distribution of permeability in granitic rocks, we carried out two-dimensional (2D) resistivity profiling, together with in-situ permeability tests, electrical logging of boreholes, and resistivity measurements of rock core samples in a laboratory. Based on the electrical logging and in-situ permeability data from boreholes, we obtained empirical equations which relate resistivity and permeability of the granitic rocks in the area studied. We then applied the empirical equation to a 2D resistivity section, to produce a 2D permeability section of the granitic rocks. In this paper, we present details of the field data and of the procedure for conversion from the resistivity section to a permeability section. The observed relationship between resistivity and permeability of the rocks is also discussed.

• 자원환경지질
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• 제28권4호
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• pp.369-379
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• 1995

About forty ore deposits of $CaF_2{\pm}Au{\pm}Ag{\pm}Cu{\pm}Pb{\pm}Zn$ are widely distributed in the Geumsan district and are believed to be genetically related to the Mesozoic Geumsan granitic rocks. Based on their petrogeochemistry and isotopic dating data, the granitic rocks in this district can be classified into two groups ; the Jurassic granitic rocks(equigranular leucocratic granite, porphyritic biotite granite, porphyritic pink-feldspar granite, seriate leucocratic granite) and the Cretaceous granitic rocks(seriate pink-feldspar granite, equigranular alkali-feldspar granite, equigranular pink-feldspar granite, miarolitic pink-feldspar granite, equigranular biotite granite). Spatial distribution of fluorite ore deposits, fluorine contents of granitic rocks and fracture patterns in this district suggest that three granitic rocks(equigranular biotite granite, equigranular pink-feldspar granite, miarolitic pink-feldspar granite) of the Cretaceous period be genetically related to the fluorite mineralization. In these fluorite-related granitic rocks, fluorine is most highly correlated with Cs(correlation coefficient(r)>0.9), and also highly with MnO, U, Sm, Yb, Lu, Zn, Y, Li(r>0.7). Statistically the variation of fluorine in the fluorite-related granitic rocks can be explained in terros of only three elements, such as Lu, CaO and Cs, and the fluorite-related granitic rocks can be discriminated from the fluorite-nonrelated granitic rocks by a linear functional equation of La, Ce, Cs and F($Z_{Ust}=-1.38341-0.00231F-0.19878Ce+0.38169La+0.54720Cs$). Also, equigranular alkali-feldspar granite is classified into the fluorite-related granitic rocks by means of the linear functional equation($Z_{Ust}$).

• 암석학회지
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• 제17권3호
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• pp.179-190
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• 2008

부산 금정구일대의 암석, 토양 및 토양가스 내 주요 환경방사성 핵종들($^{40}K$, $^{228}Ac$, $^{226}Ra$, $^{222}Rn$) 및 U의 분포 특성에 대하여 연구하였다. 연구지역의 화강암질 암석들에서 환경방사성 핵종들의 방사능은 $^{40}K$>토륨붕괴계열>우라늄붕괴계열 순으로 낮게 나타나 화강암질 암석에서 U에 비해 Th이 상대적으로 많이 부화됨을 잘 나타내고 있다. 그러나 암석 내 U 농도 및 $^{226}Ra$ and $^{228}Ac$ 방사능은 암석의 분화단계를 잘 반영하지 못하고 있다. 잔류토양 내 환경방사성 이 핵종들의 방사능과 U의 농도는 모암에 비해 높게 나타나며. 토양가스, 토양 및 암석에서 환경방사성 핵종들의 분포는 낮은 정의 상관관계를 보인다. 이러한 사실들은, 토양가스 및 토양에서 환경방사성 핵종들의 방사능은 모암에 의한 영향보다, 암석의 풍화작용과 토양형성작용 동안 이들 핵종들과 모핵종들의 용탈 및 흡착 등의 거동 특성에 의한 영향을 더 크게 받음을 시사한다.

• 자원환경지질
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• 제17권2호
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• pp.91-100
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• 1984

The Gwangyang gold deposits geologically consist of granitic gneiss, metatectic gneiss and porphyroblastic gneiss which correspond to Jirisan gneiss complex. The formations of Gyeongsang system lies unconformably on these gneisses and are intruded by diorite, porphyritic andesite and Bulgugsa granites. Goheung districts are composed of quartz schist, andesitic rock, tuff and granite. The Gwangyang gold deposits are gold bearing fissure filling veins. The vein thickness varies from 15cm to 40cm and they consist of 7-10 layers in parallel. The Goheung copper deposits are sulphide bearing quartz veln which filled the fracture in andesitic rock and biotite granite. The contact zone of these rocks is partially altered. The mineral paragenesis of the Gwangyang and Goheung districts is pyrite, arsenopyrite, pyrrhotite, chalcopyrite, sphalerite, galena, sericite, quartz and calcite. The variation trends of FMA and A'KF triangular diagrams and the differentiation index (norm, Q + Or + Ab) versus oxides diagrams is similar to the Gyeonsang basin igneous rocks. From the trace element analysis of 10 samples of country rocks, wall rocks and veins, the distribution of copper and lead contents display a correlative distribution pattern in relation to gold and silver. Homogenization temperature of fluid inclusions range from $200^{\circ}C$ to $270^{\circ}C$ in quartz from the Gwangyang gold vein and the size of fluid inclusion range from 0.01mm to 0.04mm. The fluid inclusions are mainly one or two phase and the filling degree of the inclusions varies from 85 to 95.

• 자원환경지질
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• 제26권1호
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• pp.67-81
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• 1993

This dissertation is a basic research on the degradation of rocks and aims at clarifying the relations between the progression of degree of weathering and the variation of chemical composition. The author wants to make clear the degradation of rocks and the process of formation of sedimentary rocks from a standpoint of elucidation of migration of elements. This study is considered to be significant not only as a part of research on the distribution of earth crust materials but as the petrogenesis of rocks. The chemical studies on the weathered rocks have been started relatively early and there are not a few researches on them: Goldich, 1938; Harris, et al., 1966; Ruxton, 1968; Berner, et al., 1982; Kanuss, 1983; Lasaga, 1984; Siagel, 1984. The degree of migration of elements in weathering is the composite result of various factors. Because, at the present time, it is difficult to clarify the individual and composite effects of each factor theoretically and quanititatively, we must accumulate empirical data and use them relatively. In such consideration the author acquired some data of chemical weathering from the chemical analysis of granitic and basaltic rocks in and around Fukuoka city, Japan and granitic rocks in and around Chonju and Iri cities, Korea. Because both rock types studied can be considered as representative materials of acidic and basic rocks compsing the earth crust, it is significant to examine the phenomena of weathering of both rock types. The following results are obtained from the analysis and examinations of chemical compositions of the original and weathered rocks. The loss rate of major elements has no uniformity, but the following relation holds in general; Ca, Na> K, Si> Mg> Fe, Al. As weathering proceeds, the ratio of $Al_2O_3/CaO$ shows increasing phenomena, and that of $Na_2O/CaO$ decreasing. The range of migration of composition is broad in basaltic rocks but narrow in granitic rocks. The reason is that the chemical weathering of basaltic rocks progresses more easily than that of granitic rocks. The chemical weathering potenitial index of basaltic rocks in larger than that of granitic rocks. The reason is that the chemical weathering of basaltic rocks proceeds more easily than that of granitic rocks. In weathering, the decrease of mobile cations such as $Ca^{2+}$, $Na^{2+}$, $Mg^{2+}$ and the increase of $H_2O$ in basaltic rocks are more obvious than in granitic rocks.

• 자원환경지질
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• 제9권2호
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• pp.85-106
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• 1976

The Bulgugsa acidic igneous rocks of the late Cretaceous age are largely distributed in Busan area, which is located in the southeastern corner of the Korean Peninsula. These igneous rocks comprise in ascending order, felsite, dacitic-rhyolitic welded tuffs, granite porphyry and granitic rocks. The former three members represent the early phase of volcanic activities, so that they are named as Jangsan volcanic rocks. The granitic rocks consist of granodiorite, hornblende biotite granite, Kumjongsan granite, fine grained granite, and Daebyen granite, represent the late phase of igneous activities. The Kumjongsan grainte, the largest pluton of the granitic mass, emplaced between two great vertical faults trending NNE. New chemical analyses of 33 rock samples of these acidic rocks are given. Their chemical compositions are generally similar to those of the late Mesozoic acidic igneous rocks of the northern Ashio mountains, and C-Zone granite group of the Ogcheon geosyncline, with their characteristic variation trends of several oxides. Their chemical compositions also show that $Al_2O_3$ is high value, and differentiation index is high, too. Systematically developing joints in Kumjungsan granite are divisible into two types at least. One is the NS-N $20^{\circ}E$ trendirig, $85^{\circ}{\sim}90^{\circ}$ dipping type of joint system which coincides with the trends of distribution of the granite mass and the dikes intruding this granite. Joints of this type may be cooling joints generated as tension cracks. The other is the $N60^{\circ}{\sim}70^{\circ}W$ or $N40^{\circ}{\sim}60^{\circ}E$ trending type of joint systems. It is considered that. joints belonging to this type may be shear joint occurring under the state of south-north tectonic couple acting at the east and west side of the granite mass. Igneous activities of the the Bulgugsa acidic igneous rocks in Busan area was taken place as. follows, formation of the magma reservoir, eruption and intrusion of felsite, consolidation of vents. and increasing vapor pressure in magma reservoir, eruption of pyroclastic flows, caldera collapse, intrusion of granite porphyry, and intrusion of granitic rocks at the latest stage.