• 자원환경지질
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• 제20권4호
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• pp.261-271
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• 1987

Muguk gold deposits are composed of quartz veins emplaced along faults in Mesozoic granodiorite. General strikes and dips of the veins are $N15{\sim}20^{\circ}W$ and $70{\sim}80^{\circ}NE$. Associated ore minerals are pyrite, arsenopyrite, sphalerite, galena, chalcopyrite, pyrrhotite, native silver, argentite, tetrahedrite and electrum. Vein mineral paragenesis is complicated by repeated fracturing, but five distinct depositional stages can be recognized. Electrum grains are associated mainly with sulfide bands formed along both margins of pale pink quartz of stage 3, and with patches of pyrite aggregate of stage 4. Before the close down in 1972, Muguk gold mine yielded more than 8 tons of gold of which major portion was produced from the No.2 vein. No.2 vein, extending about 1,500m laterally, was exploited to a depth of about 750m. In 1984, Young-poong mining company acquired the mining property and began geologic mapping, geochemical and geophysical exploration, diamond drilling and exploration tunnelling around the mine area to seek for other rich gold-bearing quartz veins. As the Samhyungje vein was disclosed to be the most rich vein, exploration works were focussed on the Samhyungje vein. As of August 1987, 22,338m of diamond drilling and 9,652m of exploration tunnelling have been undertaken. Owing to the successful result of exploration, the Muguk mine commenced normal operation on January 1987, treating 5,500 tons of ore per month.

• 보존과학연구
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• 통권27호
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• pp.103-128
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• 2006

Rock properties of the five storied stone pagoda in the Mooryangsa temple are consist mainly in medium grained biotite granite with partly pegmatite veinlet. A part of the foundation stone is substituted in identical rock properties of the pagoda. The upper part of the pagoda is used purples and stone, gray shale and granodiorite. The most serious problem of the pagoda is structual instability from centered subsidence of the ground in northwestern direction remarkably. In southern view, the upper part of the pagoda also is slanted a little in right, it will need reinforcement by engineering method for structual stability of the stone pagoda. Weathering states of the stone pagoda are affected results of natural and artifical factors due to the surface-exfoliation, fine-fissure, crack, falling offs. On the rock surface of the pagoda, ferro-manganese hydroxide compounds are coated along the rainpathway. Also, bryophyte range concentration spreads raindrops face of roof rock properties, which areadd biological weathering effects. For the synthetic evaluation of the deterioration state, we make detailed surface weathering maps, it will be contribute to investigation for future conservation schemes.

• 대한원격탐사학회지
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• 제3권1호
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• pp.1-10
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• 1987

The study was performed to recognize the most preferable spectral chennels for discriminating geological materials using the portable radiometer. The portable radiometer covers the visible and short infrared regions from approximately 0.4 to 2.5 microns which are coincided with Landsat TM, and the rock samples used for the study are pyrophylites, andesites, granite, granodiorite and silicified sedimentary rocks which are collected in Yangsan-Dongrae fault area. The analysis of the rock sample provides a preliminary basis for determining the wavelength regions showing diagnostic spectral features and for discriminating hydrothermal altered rocks from the unaltered rocks. The measurement of spectral of spectral reflectance for the rock samples was carried out in the laboratory which environment condition such as temperature, light sources, and humidity are constant. The analysis of the measured data was based on correlation between the reflectance value of the rock samples, and the follow discriptions are output of the study. 1) Pyrophyllite shows absorption at 0.83 $\mu\textrm{m}$ due to the oxidation of pyrite, and absorption at 2.22 $\mu\textrm{m}$ due to OH. 2) The altered rocks have generally higher reflectance than the unaltered rocks. 3) The ratio mesurement of pyrophyllites shows strong absorption at band 5/6 and band 6/4(in Landsat TM 5/7, 7/4). The ratio 1/5(Landsat TM 1/5) may be useful to discriminate andesite from the granite.

• 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.

• 자원환경지질
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• 제27권2호
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• pp.181-190
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• 1994

Petrochemical study on the micrographic granite distributed in the Wando area, the southernmost part of the Yeongdong-Kwangju depression is performed to investigate the petrogenesis and differentiation processes of the granitic magma. Polarized light microscopy for modal analyses, electron probe microanalyses of feldspars and biotite, inductively coupled plasma analyses for major and trace element contents were adopted in the study. The lithology of the study area consists of Precambrian metasediments, Mesozoic volcanic and sedimentary rocks, and micrographic granite which intrude into the former. The micrographic granite in the Wando area are distributed in the shape of a cauldron. Modal and nonnative mineral analyses of the micrographic granite fall in the area of granite and granodiorite. The chemical composition indicates that the micrographic granite is I-type and magnetite series. The micrographic granite is characterized by more than 90% of micrographic texture in volume percent. Feldspars in the micrographic granite is alkali feldspars (Or, 45~93) and plagioclases (albite to oligoclase). The biotite has a intermediate composition between phlogopite and annite solid solution. The results of the petrochemical studies indicate that the granitic magma of calc-alkaline source materials reactivated in a compressional environment at the continental margin, and then was differentiated by fractional crystallization. The micrographic granite intruded into a shallow level of the crust (5~7 km) in the late Cretaceous.

• 자원환경지질
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• 제44권1호
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• pp.11-20
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• 2011

페루 남중부 아방까이 일대 수빠라우라 지역 산화동 산출지의 주변지질, 광상조사를 실시했다. 조사지역은 중생대 백악기의 석회암과 사암층을 기반암으로 하여 신생대 제 3기 화강섬록암, 토날라이트, 안산암질 반암 등이 기반암을 관입하고 있다. $N70^{\circ}W$ 주향과 $60^{\circ}NE$ 경사의 적색 사암 층리변을 따라 최대 30 cm 폭의 동광화작용이 관찰된다. 이는 반암형 시스템에서 일반적으로 발달하는 동광화작용과는 완전히 다른 변질작용, 광물조합, 산출특성 등을 가지며, 미시시피 밸리 유형에 해당하는 층준큐제형 퇴적암-모암 동광상 (Stratiform Sediment-hosted Copper deposits: SSC)에 대비될 수 있을 것으로 사료된다.

• 한국광물학회지
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• 제16권2호
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• pp.181-189
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• 2003

킹죠지섬에 분포하는 빙하쇄설물의 화학적 풍화작용의 유무를 탐색한 결과, 다양한 풍화조직들과 이차광물들이 관찰되었다. 지표에 노출된 안산현무암질 응회암 각력에는 방해석이 선택적으로 용해되어 형성된 풍화테들이 형성되어 있다. 풍성화산유리의 가장자리에는 Al, Fe, Ti가 상대적으로 농집된 매우 얇은 용탈층이 존재하며, 앨로패인과 철산화물 등으로 구성되어 있다. 화강섬록암 지역의 흑운모는 질석과 흑운모-질석 혼합층으로 변질되었으며 드물게 아주 미량의 캐올리나이트나 깁사이트가 생성되었다. 열수변질대 지역의 황철석은 산화철로 풍화되었으며, 주변의 녹니석은 부분적으로 팽윤성광물로 풍화되었다. 그러나 사장석과 K장석 등은 거의 변질되지 않았다. 바톤반도의 빙하쇄설물은 미약하나마 화학적 풍화작용을 받아 앨로패인과 산화철 등의 이차광물이 생성되고 있으나, 킹죠지섬 주변 해양 퇴적물에 풍부한 스멕타이트의 대량 생성은 관찰되지 않았다.

• 자원환경지질
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• 제31권1호
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• pp.31-43
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• 1998

A total of 469 granitic samples were collected from 44 sites in the Ulsan fault area, southeast Korea. According to the previous petrographic studies, the granitic rocks have been divided into four groups (Hornblende biotite granodiorite, Hornblende granite, Biotite granite and Alkali-feldspar granite). NRM intensities, values of low field magnetic susceptibility, and magnetic behaviors during stepwise demagnetization experiments suggest rather a three-fold classification: In this scheme, Hornblende granite and Biotite granite are grouped together, as they did not show any significant differences in magnetic characteristics. Based on the Ishihara (1979)'s criterion, Alkali-feldspar granite is classified as ilmenite-series granite, whereas others are classified as magnetite-series granite. In the eastern part of the study area including the Tertiary basin area, declinations of site-mean characteristic remanent magnetizations (ChRMs) show clockwise deflection of more than 30 from the reference direction of east Asia. Both along and in the adjacent region of the Ulsan fault-line, however, no deflection of remanent direction was observed. A boundary line between the deflected and undeflected site-mean ChRMs is defined in this study, which runs roughly parallel to the Ulsan fault-line at the distance of about 6km eastward from the fault-line. We suggest that this newly found boundary line, which we call Yonil tectonic line, released dextral simple shear stress acted in the southeastern part of the Korean peninsula during the opening stage of the East Sea in the Early Cenozoic.

• 보존과학회지
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• 제17권
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• pp.5-18
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• 2005

논산 관촉사 석등은 암회색을 띠는 화강섬록암으로 구성되어 있다 이 석등은 전체적으로 S자형으로 뒤틀려 있으며 상대석과 1층 옥개석 하부에는 표면박리가 발생하여 석재의 표면이 심하게 부서지고 있다. 이차적 오염도 심각하여 . 부재사이에 삽입된 철편의 산화에 의한 변색과 강수의 유동흔적을 따라 나타나는 회백색 및 암흑색의 침전물이 산재한다. 석등의 표면에는 지의류와 선태류가 피복되어 있어 다양한 형태의 생물학적 훼손을 저감하기 위한 보존처리가 요구된다 또한 석등의 구조적 안정과 표면마모 및 기계적 풍화를 저지하기 위해 환경변화에 대한 장기적인 모니터 링과 함께 풍화요소를 저감할 수 있는 보존방법을 강구해야 할 것이다. 이 석등의 부재는 산출상태와 암석학적 및 지구화학적 특성이 주변의 기반암과 동일한 성인을 갖는 것으로 보아 주변의 석재를 이용하여 석등을 제작하였을 가능성이 높다.

• 보존과학회지
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• 제8권1호
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• pp.1-9
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• 1999

석굴암은 해체, 복원 및 수차례에 걸친 보수과정을 거쳐 지금에 이르렀다. 현재와 같은 비교적 안정된 환경이 이루어지기 전 까지 오랜 시간에 걸친 자연적인 풍화와 사람에 의한 영향 등에 의해 많은 변화를 겪어 왔다. 석굴암을 이루는 암석은 중립 내지 조립질의 화강섬록암으로 대체로 갈색에서 암갈색에 이르는 풍화면을 보이는데 이는 이 암석의 주구성광물인 장석류의 화학적 풍화에 기인한다. 또한 콘크리트돔이나 균열된 곳에 사용된 시멘트의 풍화물에 의한 표백 및 백화 현상 등에 의해 부분적으로 우백색을 띠거나 때로는 매우 검게 변색되어 있기도 한다. 여러 곳에 크고 작은 균열들이 발달되어 있으며 이는 주로 오랜 풍화작용에 의한 영향과 해체-복원 및 보수 과정중의 충격등에 기인하는 것으로 생각된다. 이러한 일반적인 현상들은 대부분이 현재와 같은 비교적 안정된 환경이 갖추어지기 전에 이루어진 것으로 생각된다. 그러나 앞으로의 더 나은 보전을 위해서는 내부 공기의 온도와 습도, 특히 위치에 따른 상대습도의 지속적인 평형유지, 구조적 균형유지, 그리고 진동 등에 의한 영향을 체계적이고 계속적으로 측정하여 대책을 수립하여야 할 것으로 생각된다.