• Economic and Environmental Geology
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• v.19 no.spc
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• pp.97-102
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• 1986

Concepts on mineral association, mineral paragenesis, and mineralization stage relating to macrostructures of vein filling in ore veins are briefly discussed. As an example of plutonic ore vein, macrostructures of vein filling of plutonic tungsten-tin-copper vein at the Ohtani mine, Kyoto Prefecture, Japan, one of representatives of plutonic tungsten-tin vein related genetically to acidic magmatism of late Cretaceous in the Inner zone of Southwest Japan, are examined. Based on macrostructures of vein filling, three major mineralization stages, are distinguished by major tectonic breaks. Sequence of mineralization, characteristic features of each mineralization stage, and variations of filling temperature and salinity ranges of fluid inclusions in minerals from stage I to stage III are summarized.

• Economic and Environmental Geology
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• v.7 no.2
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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.

• Economic and Environmental Geology
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• v.21 no.4
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• pp.389-400
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• 1988

Minor elements such as Ag, As, Au, Bi, Cd, Cu, Co, Ni, Pb, Rb, Sb, Sr and Te were analyzed by atomic absorption spectrophotometry and induced coupled plasma spectrophotometry in order to investigate pathfinders for gold in quartz porphyry, granite porphyry and vein materials in Jeonjuil gold - silver mine, and in altered biotite granites and vein materials in Dukum gold - silver mine. In Dukum gold - silver mine, it is observed that Au contents have positive relation with As, Co, and Rb contents, but negative relation with Bi contents in altered biotite granites. Au contents have positive relation with Ag, As, Co and Te contents in vein materials. In Jeonjuil gold - silver mine, it is observed that Cd, Rb, Sr and Te are enriched near ore vein in quartz porphyry and granite porphyry. Au contents have positive relation with As, Cd, Cu, $Fe_2O_3$ and $K_2O$ in vein materials.

• Economic and Environmental Geology
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• v.10 no.1
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• pp.1-18
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• 1977

Chongyang tungsten ore deposits, one of the most important tungsten mines in South Korea, me open space filling hydrothermal vein deposits embedded in Precambrian biotite gneiss and, Cretaceous (?) granite porphyry. Some wolframite-bearing quartz veins are closely associated with -quartz porphyries which strike about $N15^{\circ}-25^{\circ}W$ and dip $800^{\circ}SE$ to vertical. Mineralization took place in near vertical vein systems of 5 to 2000 meter long in the biotite gneiss and granite porphyry stock during early Cretaceous and Tertiary (?) period. The hydrothermal mineral paragensis has indicated that there were two major stages: vein and vug stages. The principal vein mineral is wolframite in a gangue of quartz with small amount of fluorite, pyrite, beryl and carbonate minerals. Present in minor amounts are molybdenite, bithmuthinite, native bismuth, arsenopyrite, galena, chalcopyrite, pyrrhotite, sphalerite and scheelite. Fluid inclusion study from the minerls at Chongyang mine reveals that vein stage fluids attained a temperature range of $200^{\circ}C-355^{\circ}C$ and vug stage $160^{\circ}C-350^{\circ}C$. The filling temperatures show the higher range of $200^{\circ}-355^{\circ}C$ in quartz and $280^{\circ}C-348^{\circ}C$ in beryls, whereas the lower emperature range of $283^{\circ}C-295^{\circ}C$ in rhodochrosite and $160^{\circ}-253^{\circ}C$ in fluorites. These temperatures are in reasonably good agreement with mineral paragnesis in this ore deposits. Volfamite minerals were analysed for major components. $WO_3$, MnO and FeO by wet chemical method. Chemical analysis indicates that they contain 70.56-71.54% $WO_3$, 8.52-10.01% MnO and 10.00-11.58% FeO. MnO/FeO ratios of wolframites shows the range of 0.78-0.94 which maybe indicates a comparatively high temperature type of hydrothermal deposits.

• Economic and Environmental Geology
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• v.24 no.4
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• pp.347-361
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• 1991

The Sangeun ore deposit is located in a volcanic belt within the Gyeongsang Basin in south western Korea. The ore deposit is of representative epithermal Au-Ag quartz vein type developed in lapilli tuff. This paper presents the mineralization with special emphasis on mineral zoning of the deposits. Principal points are summarized as follows: (1) Four stages of mineralization are recognized based on macrostructures. From ealier to later they are stage I(arsenopyrite-pyrite-quartz), stage II(Au-Ag bearing Pb-Zn-quartz), stage III(barren quartz), and stage IV(dickite-quartz). (2) Electrum principally occurs with arsenopyrite and galena in stage II, and has chemical compositions of 72.9-67.1 Ag atom %, and has Ag/Au ratio of 2.69-2.04. (3) Sphalerite varies in its FeS content according to the mineralization stages; 22.03-18.60 mole % FeS and 1.33-0.23 mole % MnS in stage IB, 16.11-8.64 mole % FeS and 1.33-0.23 mole % MnS in stage II. (4) Alteration zones of mineral assemblage, from the vein to the wall-rock, consist of sericite - quartz - pyrite, sericite - quartz - dickite, sericite - chlorite plagioclase respectively.

• Economic and Environmental Geology
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• v.23 no.2
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• pp.183-199
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• 1990

Ore deposits of Dongwon mine are composed of numerous gold and silver veins emplaced in sedimentary rocks of Cambrian Choseon Supergroup and granitoids of Cretaceous age. Ore veins of the mine can be divided into gold and silver veins on the base of vein structure, mineral assemblage and vein trends. Mutual relationships between gold and silver veins are uncertain. Gold veins are simple veins which are composed of base-metal sulfides, and electrum with quartz and ankerite. On the other hand, silver veins are complex veins which reveal three distinct stages of mineral deposition based on vein structure; stage I, deposition of small amounts of oxides and pyrite with quartz; stage II, deposition of base-metal sulfides, small amounts of Ag-bearing minerals, calcite and quartz; stage III, deposition of base metal sulfides, electrum, Ag-sulfosalts, native silver, carbonates and quartz. Homogenization temperature and salinity of fluid inclusion from quartz of gold vein are as follows; $229^{\circ}$ to $283^{\circ}C$, 4.7 to 6.4 wt.% equivalent NaCI. The ore mineralogy suggests that temperature(T) and sulfur fugacity($fs_2$) of the formation of the gold vein and stage III of silver vein are estimated as T ; $294^{\circ}$ to $318^{\circ}C$, $fs_2\;10^{-9.4}$ to $10^{-10.1}$ atm. and T; $240^{\circ}$ to $279^{\circ}C$, $fs_2;10^{-11.1}$ to $10^{-17.3}$ atm. respectively. Pressure condition during gold vein formation estimated from data of ore mineralogy and fluid inclusion range 500 to 750 bar.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.254-256
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• 2003

A total of one hundred and twenty three goldbearing mineral deposits in the Charters Towers area west of Townswille, Queensland, Australia were initially classified into four named and unnamed separate vein styles, with different trends and alteration patterns, a breccia-style deposit and placer gold deposits. The area has vein deposits in Ordovician and Silurian granitoids and breccia-style in the Carboniferous volcanics. In this paper a modeling of these deposits is described using geological mapping, landscape analysis and digital imagery (Landsat TM and geophysics) to improve the classification and identification of possible new target for exploration.

• Economic and Environmental Geology
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• v.18 no.2
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• pp.135-138
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• 1985

The radioautographing of U-bearing cloaly slate samples were initiated in order to clarify the uranium distribution patterns in the samples of Ogcheon system. Moreover, x-ray powder diffraction and x-ray single crystal analysis studies were undertaken to identify the uranium mineral which was extracted from U-bearing coaly slate. The handspecimens were collected from the Boseong mine, located in Deokpyeong area, Goesan-gun, Chungcheongbug-do. According to the experimental studies, it has been found the following facts: (1) fixed carbon has close relation with uranium contents, (2) quartz veins developed in U-bearing coaly slate are diveded into two groups based on mode of occurrence, formation stage and uranium distribution pattern; early quartz vein ($QV_1$) with low uranium concentration and late quartz vein ($QV_2$) with high uranium concentration, (3) matrixes around $QV_1$ are displayed homogeneous and high uranium concentration, while matrixes around $QV_2$ are low uranium concentration, (4) uranium mineral is identified as a variety of autunite.

• Economic and Environmental Geology
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• v.13 no.2
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• pp.117-127
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• 1980

Molybdenum as by-products of Sangdong tungsten mine occurrs in the form of molybdenite in quartz vein. The molybdenum contents of scheelite in Sangdong ore bodies ranges from trace to 8%, therefore the scheelites show variable fluorescence colores under ultra-violet lamp (short wave). The fluorescence color are in order high content of molybdenum, yellow, white and blue. The yellow fluorescing scheelite is dominant in upper ore vein, otherwise the blue fluorescent variety is dominant in lower ore vein. The fluorescence color of scheelite in the main ore vein show zonal distribution becoming progressively more blue outerwards, contrary more yellow innerwards, and even in single scheelite crystal, simillar zonal pattern is observed, too. Molybdenite occurrs as flakes or elongated blades at the margins of the quartz vein only molybdenite bearing quartz veins but also other sulfides mineral bearing quartz veins have mainly blue flourescing scheelites. We suggest that the molybdenum contents of the early stage ore solution are progressively decreased by a subsequent crystallization of the yellow fluorescing scheelites.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.1
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• pp.1-14
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• 2021

The Unsang gold deposit has been one of the three largest deposits (Daeyudong, Kwangyang) in Korea. The geology of this deposit consists of series of host rocks including Precambrian metasedimentary rock and Jurassic Porphyritic granite. The deposit consists of Au-bearing quartz veins which filled fractures along fault zones in Precambrian metasedimentary rock and Jurassic Porphyritic granite, which suggests that it is an orogenic-type deposit. Quartz veins are classified as 1) galena-quartz vein type, 2) pyrrhotite-quartz vein type, 3) pyrite-quartz vein type, 4) pegmatic quartz vein type, 5) muscovite-quartz vein type and 6) simple quartz vein type based on mineral assembles. The studied quartz vein is pyrite-quartz vein type which occurs as sericitization, chloritization and silicification. The white mica from stylolitic seams of laminated quartz vein occurs as fine or medium aggregate associated with white quartz, pyrite, chlorite, rutile, monazite, apatite, K-feldspar, zircon and calcite. The structural formular of white mica from laminated quartz vein is (K0.98-0.86Na0.02-0.00Ca0.01-0.00Ba0.01-0.00 Sr0.00)1.00-0.88(Al1.70-1.57Mg0.22-0.09Fe0.23-0.10Mn0.00Ti0.04-0.02Cr0.01-0.00V0.00Ni0.00)2.06-1.95 (Si3.38-3.17Al0.83-0.62)4.00O10(OH2.00-1.91F0.09-0.00)2.00. It indicated that white mica of laminated quartz vein has less K, Na and Ca, and more Si than theoretical dioctahedral micas. Compositional variations in white mica from laminated quartz vein are caused by phengitic or Tschermark substitution [(Al3+)VI+(Al3+)IV <-> (Fe2+ or Mg2+)VI+(Si4+)IV] and direct (Fe3+)VI <-> (Al3+)VI substitution. The structural formular of chlorite from laminated quartz vein is((Mg1.11-0.80Fe3.69-3.14Mn0.01-0.00Zn0.01-0.00K0.07-0.01Na0.01-0.00Ca0.04-0.01Al1.66-1.09)5.75-5.69 (Si3.49-2.96Al1.04-0.51)4.00O10 (OH)8. It indicated that chlorite of laminated quartz vein has more Si than theoretical chlorite. Compositional variations in chlorite from laminated quartz vein are caused by phengitic or Tschermark substitution (Al3+,VI+Al3+,IV <-> (Fe2+ or Mg2+)VI+(Si4+)IV) and octahedral Fe2+ <-> Mg2+ (Mn2+) substitution. Therefore, laminated quartz vein and alteration minerals of the Unsan Au deposit was formed during ductile shear stage of orogeny.