• 자원환경지질
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• 제7권2호
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• pp.45-62
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• 1974

Scheelite deposits in Sangdong mine are divided into three parallel vein groups, namely "Hanging-wall vein" which is located in the lowest parts of Pungchon Limestone, "Main vein" the most productive vein replaced a intercalated limestone bed in Myobong slate, "Foot-wall veins" a group of several thin veins parallel to main vein in Myobong slate. Besides the above, there are many productive quartz veins imbedded in the above veins and Myobong slate. Molybdenite and wolframite are barren in the former three veins group but associates only in quartz veins. Both main vein and foot-wall veins show regular zonal distribution, quartz rich zone in the center, hornblende rich zone surrounding the quartz rich zone and diopside rich zone in the further outside to the marginal parts of the vein. According to the distribution of three main minerals, quartz, hornblende and diopside the main vein can be divided into three zones which are in turn grouped into 7 subzones by distinct mineral paragenesis. They are summerized as follows: A. Diopside rich zone: 1. garnet-diopside.fl.uorite subzone 2. diopside-zoisite-quartz subzone 3. diopside-plagioclase subzone B. Hornblende rich zone: 4. hornblende-diopside-quartz subzone 5. hornblende-quartz-chlorite subzone 6. hornblende-plagioclase-quartz.sphene subzone C. Quartz rich zone: 7. quartz-mica-chlorite subzone The foot-wall veins can similarly be divided by mineral paragenesis into 3 zones, 6 subzones as follows: A. diopside rich zone: 1. garnet-diopside-quartz.fl.uorite subzone 2. garnet-diopside-wollastonite subzone B. Hornblende rich zone: 3. quartz-hornblende-chlorite subzone 4. hornblende-plagioclase-quartz subzone 5. hornblende-diopside-quartz subzone C. Quartz rich zone: 6. quartz-mica subzone The hanging-wall vein is generally grouped into 9 subzones by the mineral paragenesis which show random distribution. They are as follows: 1. diopside-garnet-fluorite subzone 2. diopside-zoisite-quartz subzone 3. diopside-hornblende-quartz-fluorite subzone 4. wollastonite-garnet-diopside subzone 5. hornblende-chlorite-quartz subzone 6. quartz-plagioclase-hornblende-sphene subzone 7. quartz-biotite subzone 8. quartz-calcite subzone 9. calcite-altered minerals subzone Among many composing minerals, garnet specially shows characteristic distribution and optical properties. Anisotropic and euhedral grossularite is generally distributed in the hanging wall vein and lower parts of the main vein, whereas isotropic and anhedral andradite in the upper parts of the main vein. Plagioclase (anorthite) and sphene are distributed ony near the foot-wall side of the aboveveins. wollastonite is a characteristic mineral in upper parts of the hang-wall vein. Molybdenite is distributed in the upper parts of quartz veins and wolframite in lower parts of quartz veins.

• 자원환경지질
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• 제26권4호
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• pp.473-487
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• 1993

The Janggun mine area is occupied by the Proterzoic and the Paleozoic meta-pelites, which are intruded by the Jurassic Chunyang granite. The metamorphic terrain is divided into four zones of progressive metamorphism on the basis of mineral assemblages. The zones are chlorite zone, staurolite zone, andalusite zone, sillimanite zone ascending order. Boundary lines between the zones resemble outline of the Chunyang granite mass. Isograd reactions are chlorite+chloritoid+muscovite=staurolite+biotite+quartz+water, staurolite+chlorite+muscovite+quartz=andalusite+biotite+water, and staurolite+muscovite+quartz=andalusite+biotite+garnet+water between the chlorite zone and the staurolite zone, the staurolite zone and the andalusite zone, and the andalusite zone and the sillimanite zone, repectively. They are univariant reactions in KFMASH component system. Metamorphic conditions estimated from garnet-biotite geothermometers and phase equlibria are $530^{\circ}C$ and lower than 4 kb.

• 자원환경지질
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• 제26권3호
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• pp.289-309
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• 1993

Milyang pyrophyllite deposit which was formed by hydrothermal alteration occurs in Late Cretaceous andesitic tuff in the Milyang area, Gyeongsangnamdo. The wall rock alteration and genesis of the Milyang pyrophyllite deposit were studied. The ore minerals are composed dominantly of pyrophyllite accompanied by small amounts of quartz, kaolinite, pyrite, dumortierite and diaspore. The alteration halo of this deposit can be divided into three zones on the basis of mineral assemblage; pyrophyllite, sericite and chlorite zone. The common mineral assemblages of each alteration zone are as follows: (1) pyrophyllite zone; pyrophyllite-quartz-kaolinite-pyrite-dumortierite-diaspore, (2) sericite zone; sericite-quartz-pyrite-kaolinite, and (3) chlorite zone; chlorite-plagioclase-quartz. Major element chemistry shows that characteristic depletion in MgO, CaO, and $Na_2O$ and relative increase in FeO from less altered chlorite zone to extensively altered pyrophyllite zone corresponding to variation in mineral assemblages. The paragenesis of ore minerals, oxygen isotope data, chlorite and illite geothermometry suggest that ore deposit was formed at about $250{\sim}330^{\circ}C$. Both hydrogen and silica activities are high in pyrophyllite zone. Potassium activity increases in sericite zone while hydrogen activity becomes low in chlorite zone. The pyrophyllite zone was formed relatively higher temperature than those of sericite and chlorite zones. The ore fluid was considered to be magmatic water in origin derived from the residual granitic magma which interacted with meteoric water.

• 자원환경지질
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• 제25권1호
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• pp.1-16
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• 1992

The Wondong Fe-Pb-Zn deposit is located in endo and exoskarns formed along the contact between the Makkol limestone interbedding pelitic limestone of Ordovician age and quartz porphyry of Cretaceous age. At the Wondong mine, the endoskarn shows a discontinuous zonal arrangement from quartz porphyry to pelitic limestone as follows: unaltered quartz porphyry, weakly altered quartz porphyry zone, intensively altered pinkish quartz porphyry zone, garnet zone, and greyish white and fine-grained clinopyroxene zone developed at pelitic limestone side. In terms of chemical mass balance, intensively altered pinkish quartz porphyry relative to unaltered quartz porphyry shows substantial enrichments in $K_2O$, $Na_2O$, and HREE and depletions in MgO, CaO, total $Fe_2O_3$, and LREE. On the other hand, garnet zone of endoskarn is enriched in CaO, MnO, total $Fe_2O_3$, MgO and depleted in $K_2O$, $Na_2O$. $Al_2O_3$ seems to be determining inert component. Thus the behavior of elements indicates that the mobility of elements depends on the equilibration of hydrothermal fluid and minerals and affects on enrichments by fractionation from and depletions by partition to hydrothermal fluid, respectively. Traversing toward pelitic limestone from a central zone of exoskarn, the exoskarn also shows a zonal arrangement as follows: garnet zone, clinopyroxene zone, and decolored pelitic limestone. The arrangement of mineral assemblages in skarns of the Wondong mine is the result of an increase in CaO and $K_2O$ toward the pelitic limestone. Skarn and ore minerals were formed in the following sequence: early skarn, late skarn and magnetite, pyrite, sphalerite, galena, and molybdenite. On the basis of stabilities of mineral assemblages, physicochemical conditions of the late skarn and magnetite mineralization are estimated to be $350^{\circ}C{\leq}T{\leq}400^{\circ}C$ at 1 Kb, $-23{\leq}log\;fO_2{\leq}-18$, and $0.005{\leq}XCO_2{\leq}0.01$, while those of the early skarn to be $420^{\circ}C{\leq}T{\leq}550^{\circ}C$ at 1 Kb.

• 자원환경지질
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• 제3권1호
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• pp.25-34
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• 1970

Very few articles are available on geologic structure and genesis of Sangdong scheelite-deposits in spite of the fact that the mine is one of the leading tungsten producer in the world. Sangdong scheelite deposits, embedded in Myobong slate of Cambrian age at the southem limb of the Hambaek syncline which strikes $N70{\sim}80^{\circ}W$ and dips $15{\sim}30^{\circ}$ northeast, comprise six parallel veins in coincide with the bedding plane of Myobong formation, namely four footwall veins, a main vein, and a hangingwall vein. Four footwall veins are discontinuous and diminish both directions in short distance and were worked at near surface in old time. Hangingwall vein is emplaced in brecciated zone in contact plane of Myobong slate and overlying Pungchon limestone bed of Cambrian age and has not been worked until recent. The main vein, presently working, continues more than 1,500 m in both strike and dip sides and has a thickness varying 3.5 to 5 m. Characteristic is the distinct zonal arrangement of the main vein along strike side which gives a clue to the genesis of the deposits. The zones symmetrically arranged in both sides from center are, in order of center to both margins, muscovite-biotite-quartz zone, biotite-hornblende-quartz zone and garnet-diopside zone. The zones grade into each other with no boundary, and minable part of the vein streches in the former two zones extending roughly 1,000 m in strike side and over 1,100 m in dip side to which mining is underway at present. The quartz in both muscovite-biotite-quartz and biotite-hornblende-quartz zones is not network type of later intrusion, but the primary constituent of the special type of rock that forms the main vein. The minable zone has been enriched several times by numerous quartz veins along post-mineral fractures in the vein which carry scheelite, molybdenite, bismuthinite, fluorite and other sulfide minerals. These quartz veins varying from few centimeter to few tens of centimeter in width are roughly parallel to the main vein although few of them are diagonal, and distributed in rich zones not beyond the vein into both walls and garnet-diopside zone. Ore grade ranges from 1.5~2.5% $WO_3$ in center zone to less than 0.5% in garnet-diopside zone at margin, biotite-hornblende-quartz zone being inbetween in garde. The grade is, in general, proportional to the content of primary quartz. Judging from regional structure in mid-central parts of South Korea, Hambaek syncline was formed by the disturbance at the end of Triassic period with which bedding thrust and accompanied feather cracks in footwall side were created in Myobong slate and brecciated zone in contact plane between Myobong slate and Pungchon limestone. These fractures acted as a pathway of hot solution from interior which was in turn differentiated in situ to form deposit of the main vein with zonal arrangement. The footwall veins were developed along feather cracks accompanied with the main thrust by intrusion of biotite-hornblende-quartz vein and the hangingwall vein in shear zone along contact plane by replacement. The main vein thus formed was enriched at later stage by hydrothermal solutions now represented by quartz veins. The main mineralization and subsequent hydrothermal enrichments had probably taken place in post-Triassic to pre-Cretaceous periods. The veins were slightly displaced by post-mineral faults which cross diagonally the vein. This hypothesis differs from those done by previous workers who postulated that the deposits were formed by pyrometasomatic to contact replacement of the intercalated thin limestone bed in Myobong slate at the end of Cretaceous period.

• 자원환경지질
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• 제30권2호
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• pp.163-174
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• 1997

Precambrian metapelites and metapsammites of the Jinan-Osu area (so-called Seologri and Yongamsan Formation) consist of black slate, phyllite, mica schist, quartzite and rarely calc schist. They are intruded by Sunkagsan granite gneiss, Foliated granodiorite, Amphibolite, Sunchang foliated granite and Namwon granite. Mylonite texture, crenulation cleavage and minor shear zone are common. The meta-sedimentary rocks include various rock-fragments xenoliths in size (up to 3 cm) and rock-type. They have various porphyroblastic spots in size (up to 1 cm) and their mineral composition is different. The xenoliths are schists, granite and quartzite, which are rectangular or lens form and recrystallized muscovite, chlorite and quartz. Spots are andalusite and biotite aggregates extensively replaced by chlorite. The metamorphic terrain is divided into three zones of progressive metamorphism on the basis of mineral assemblage. They are chlorite zone, chloite-biotite zone and andalusite-biotite zone ascending order, from west to east approximately. Isograd reactions are phengitic muscovite + chlorite = less phengitic muscovite + biotite + quartz + $H_2O$ and muscovite + chlorite + quartz = andalusite + biotite + $H_2O$ between the chlorite zone and chlorite-biotite zone, and between the chloritebiotite zone and andalusite-biotite zone, respectively. Sample B6 (exposed near the Obong-ri) includes staurolites and greenish biotites, that is different in mineral assemblage and chemical composition from the meta-sedimentary rocks. Sample A12 (exposed near the Shinam-ri) has greenish white spots (up to 1 cm in diameter) mainly composed of Kfeldspar, quartz and sillimanite replaced by muscovite.

• 자원환경지질
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• 제12권4호
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• pp.197-206
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• 1979

Sangdong scheelite deposit is confirmed to have been formed by replacement of limestone beds by metasomatic mineralization. Mineralogical zonal distribution and filling temperatures are related with order of its formation and tungsten mineralization. The first formed garnet-pyroxene zone, left in the margins of the ore body, shows the highest filling temperature of fluid inclusions in pyroxene, averaging $420^{\circ}C$. The central part of the ore body, mainly composed of quartz-mica-scheelite, shows higher fi11ing temperatures of fluid inclusions in quartz, than hornblende-quartz-scheelite zone surrounding the quartz-mica-scheelite zone, averaging $240^{\circ}C$. The distribution of highter filling temperatures above average temperature is applicable to the richest part of scheelite distribution. Generally scheelite shows higher filling temperature by about 20 to $100^{\circ}C$ than quartz in a given sample. The crystallization temperature of the main phase of scheelite deposition is $311^{\circ}C$ at the pressure of 230 to 500 bars at Sangdong area. Gas-rich inclusions in the pyroxene are homogenized into either gas or liquid phase or into both phases in a given crystal of the pyroxene, which suggests boiling at the formation of skarn.

• 자원환경지질
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• 제25권4호
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• pp.397-416
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• 1992

본 논문에서는 해남지역의 점토광상인 성산, 옥매산 및 해남광상을 연구대상으로 하였다. 열수변질을 받은 각 점토광상은 중심으로부터 주변부로 감에 따라 변질대를 형성하고 있는데, 성산광상의 경우 카올린대, 카올린-석영대, 견운모대 및 녹니석대의 변질대가, 옥매산광상의 경우 석영대, 명반석대, 카올린대, 견운모대 및 녹니석대의 변질대가, 그리고 해남광상의 경우 석영대, 납석대, 견운모대 및 녹니석대의 변질대가 각각 나타나고 있다. 이같은 변질대들은 두 종류의 변질작용으로 구분될 수 있는데, 하나는 납석대, 명반석대, 석영대, 카올린대 및 카올린-석영대와 같은 산변질작용 (acidic alteration)이고, 다른 하나는 녹니석대와 일부 견운모대와 같은 프로필리틱 (prophylitic alteration) 이다. 모든 점토광상은 high sulfidation (acidic-sulfate) 계에 속한다. 산변질작용의 암석은 납석, 명반석, 카올린광물, 견운모, 석영 및 황철석 등으로 구성되어 있다. 전암화학분석의 결과 $SiO_2$, $TiO_2$, $Fe_2O_3$, MgO, CaO, $K_2O$ 및 $Na_2O$와 같은 원소들은 원암의 조성과 상당한 차이를 보여주고 있는데, 이같은 주원소들의 유동성은 각 변질대의 광물조합과 관련되어 이들에 영향을 주고 있다. 견운모의 폴리타잎(polytype) 은 X-선 회절분석결과, $2M_1$ 및 1M 형으로 밝혀졌다. 성산광상의 경우 $2M_1$ 및 1M 형이 거의 같은 비율로 나타나고, 옥매산광상의 경우 1M 형이 우세한 반면, 해남광상의 경우 $2M_1$ 형이 우세하게 나타나고 있다. 이같은 현상은 견운모의 형성온도를 반영하는 것으로, 해남광상이 가장 고온에서, 성산광상은 중간온도에서, 그리고 옥매산광상이 가장 저온에서 형성되었음을 지시해 준다. 전자현미 분석결과, 면반석의 Na/(K+Na)의 비율이 옥매산광상의 것이 성산광상의 명반석이 성산광상의 것보다 높은 것으로 나타났는데, 이는 옥매산광상의 것보다 상대적으로 고온에서 높은 Na/(K+Na) 값과 낮은 pH 값을 갖는 용액에서 형성되었음을 시사해 준다. 모든 분석결과를 종합하여 볼 때, 명반석은 hypogene 기원이며, steam-heated 환경에서 hydrogen sulfide의 산화작용에 의하여, 그리고 오늘날의 열수계에서 관찰할 수 있는 solfataric alteration의 결과로 형성되었음을 알 수 있다.

• 암석학회지
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• 제23권1호
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• pp.1-15
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• 2014

한반도 남서단부의 영암광화대에는 상은과 은적 그리고 바람재 광산이 발달하고 있다. 이 지역은 목포-해남-영암 지역에 걸쳐 확인되는 대규모 화산성 환상구조의 북동부에 해당한다. 조사지역인 상은-은적-바람재 지역에서 확인된 13개소의 석영맥과 광화대는 유문암질 용결응회암을 모암으로 하고 있으며, 주로 남-북 내지는 북북서 방향의 주향에 서측으로 고각도를 이루고 있다. 상은, 은적, 바람재 지역에 발달하는 석영맥은 단일맥인 경우도 있으나, 주로 폭 1-5 cm의 맥들로 다발을 이루는 특징을 보인다. 석영맥과 평행하게 발달하는 단층면의 발달로 보아 석영맥의 관입과 광화작용의 전후에 단층운동이 존재했음을 지시한다. 또한 이들 석영맥과 광화대는 광화작용 후기에 작용한 북서 방향의 좌향이동 단층에 의해 변위된 양상을 보인다. 북서 방향의 단층은 불치와 상은광산 부근에서 잘 관찰되며, 장동리와 장천리 일대의 석영맥의 분포나 선상구조에 의해서도 이 단층과 평행한 단층들이 발달할 것으로 판단된다. 조사지역의 서측인 상은적산 남측에서 서측으로 북서 주향의 석영맥이 관찰된다. 은적-상은 광상 주변에서 확인된 12개 석영맥의 현장조사 및 금, 은 품위의 분석 결과에 의하면, 남측으로 가면서 석영맥의 발달 양상이 미약해 지고 있다. 바람재 부근 광상의 경우 북북서-남남동 방향의 석영맥이 약 20 m 연장되고 있다. 섬아연석, 방연석 등 유화광물은 함유하고 있으나 금-은의 발달은 미약하다. 금품위가 평균 <0.1 g/t, 은품위가 평균 5.7 g/t으로 은적광산(금; 12.3 g/t, 은; 1,380.0 g/t)과 상은광산(금; 2.7 g/t, 은; 23.5 g/t)에 비해 남측으로 가면서 금, 은의 품위는 현저히 떨어지는 반면, 그 외 연, 아연 등 유화광물 함량은 증가하는 양상을 보인다.

• 암석학회지
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• 제6권3호
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• pp.226-243
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• 1997

오대산편마암복합체는 미그마타이트질편마암과 반상변정질편마암이 주를 이루며, 소규모의 규암, 앰피볼라이트, 대리암 및 우백질편마암 등이 렌즈상으로 협재되어있다. 이 지역은 최소 2회의 공역변성작용을 받았다. 1차 변성작용시 변성정도는 흑운모-백운모-사장석-석영, 석류석-흑운모-백운모-K-장석-사장석-석영의 광물조합 등을 보이는 동부 및 서남부지역의 K-장석-백운모분대로부터 석류석-흑운모-K-장석-사장석-석영, 흑운모-K-장석-사장석-석영, 석류석-흑운모-K-장석-사장석-규선석-스피넬-석영의 광물조합을 보이는 북서부지역의 K-장석-석류석분대로 증가한다. 사장석 내부에 남정석이 잔류물로 나타난다. 2차 변성작용은 근청석의 생성이 특징적이다. 2차 변성작용시의 변성정도는 근청석-석류석-규선석-흑운모-백운모-석영, 근청석-석류석-스피넬-규선석-흑운모-백운모-석영의 광물조합을 보여주는 개인산을 중심으로하는 석류석-근청석 분대로부터 방사상으로 감소한다. 그 결과 근청석-규선석-흑운모-사장석-석영, 근청석-흑운모-백운모-사장석-석영, 규선석-흑운모-백운모-사장석의 광물 조합을 가지는 규선석-근청석분대가 석류석-근청석분대를 둘러싸며 나타난다. 석류석-흑운모-규선석-K-장석-사장석-스피넬의 광물조합으로부터 계산된 1차 변성작용시의 최대 변성압력-온도조건은 5.4~7.4kb, $776~789^{\circ}C$이나 상평형관계를 고려할 때 실제 변성압력-온도조건은 계산된 조건보다 높았을 가능성이 있다. 사장석내에 잔존하는 석류석-흑운모-사장석에 대한 변성압력-온도조건은 12.5kb, $650^{\circ}C$로 1차 변성작용이 매우 높은 압력경로를 거친후 최대변성 온도조건에 도달했음을 지시한다. 2차 변성작용에서 석류석-흑운모-근청석-스피넬-석영의 광물조합에서 계산된 2차 변성작용시의 압력-온도조건은 6 kb 이하, $680~750^{\circ}C$이다. 오대산편마암복합체에서는 고압의 변성작용과 급격한 지각의 상승을 거친후 중압고온의 1차 변성작용이 일어났으며 구룡층군의 퇴적이후 저압고온의 2차 변성작용이 일어났다.