• Economic and Environmental Geology
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• v.5 no.3
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• pp.133-144
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• 1972

The mine of our present concern is situated at Shim-ri, Gusan-myon, Changwon-gun, Kyongsang-namdo, with lattitude $128^{\circ}35^{\prime}{\sim}36^{\prime}N$ and longitude $35^{\circ}03^{\prime}{\sim}04^{\prime}E$. This mine has not been noticed until the intermittent geological survey for the ore deposits were initiated from September, 1967 till 1970. The main mineralized zones, No.1 and No.2 zones, were studied by the diamond drilling of 9 holes down to the total depth of 1,140m, and found to have ore reserves of Cu 1.99% ore, estimated to reach around $358,000{\frac{M}{T}}$ (proved $117,000{\frac{M}{T}}$, indicated $241,000{\frac{M}{T}}$), which triggered the new exploitation of this mine. Geological composition of the district near the mine is mainly from the andesite belonging to the Silla Series of Kyongsang System and the distribution is broadly spread. Ore deposits are the hydrothermal one, filling the shear zone formed alongside the andesite main joint. There are two stripes of copper bearing mineralized zone which are about 40~70 meters apart and parallel to each other, in addition to which two others are expected. The strike of the main mineralized zone lies at $N15^{\circ}{\sim}20^{\circ}W$, the dip at $60^{\circ}{\sim}70^{\circ}NE$. The principal components of the ore mineral are chalcopyrite, bornite and as secondary, cuprite, tenorite, azurite and malachite. Pyrite, magnetite, specular hematite, very little of galena, sphalerite, quartz, epidote, zoisite, chlorite and calcite are found as gangue mineral. Confirmed by the drilling, the main mineralized zone, No.1 zone, has the length of 320m, average width of 1.62m, Ag 26g/t, Cu 1.84% and the average width of the ore zone except the narrow barren andesite horse interposed in the mineralized zone is 1.32m with Ag 32g/t and Cu 2.26%. The mineralized zone No.2 is 340m long, 1.00m wide with Ag 30g/t and Cu 2.15%. Neglecting the barren andesite horse the width is 0.73m with Ag 42g/t and Cu 2.94%.

• Economic and Environmental Geology
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• v.6 no.3
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• pp.133-170
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• 1973

The metamorphosed belt on cherty and andesitic rocks of the Gyeongnam province area has been well known as the most important copper matallogenetic province in Korea and locally has been investigated by several geologists. This report is summarized about geology, occurrence of ore deposits, the study of the present status of mine developments and exploitations and the suggestions of future proposed of copper mine developments and harmoniously and reseonably planning of demands and supply of copper ore. For convenience of study the writer divided the survey region as 4 areas, according to the conditions of mine location. They are (1) Goseong copper area (2) Gunbuk-Haman copper area (3) Masan-Changwon copper area (4) Tongrae-Ilgwang copper area. The geology of the above 4 areas consits of Cretaceous Gyongsang System, which is divided into Silla series, Nakdong Series and Bulguksa Series. The former has intrusive and extrusive andesite and sedimentary formation, and the latter has dioritic and hornblende granite. Ore deposits which is mostly vein types are confined mostly in the andesite and cherty rocks of Silla and Nakdong Series. It is observed slight hydrothermal alteration, i. e. propylitization, chloritization, saussuritization and silicification. It seems that the ore was formed by hydrothermal solution and secondary enrichement. The ore minerals are mainly chalcopyrite and pyrite, with small amounts of malachite, azurite, chalcocite, cuprite, galena, and sphalerite, magnetite, tetrahedrite and etc.. The efficient plan of copper mine developments in surveyed region are as following; (a) Gyeongnam Copper districts are divided in 4 area as mentioned above. (b) Each area would be likely developed as group-working as one unit. For the sufficiently supplying a demand of electric copper, the importations of high grade copper ore in foreign country are invitable at present status of copper mine developments and exploitations.

• Economic and Environmental Geology
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• v.23 no.1
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• pp.25-33
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• 1990

Gold-silver deposits of Deogheun and Beopjeon mines are composed of veins emplaced in Jurassic granite batholith. Based on ore structure and ore mineralogy, four distinct stages of mineral deposition are recognized in these ore deposits. Gold and silver minerals in Deogheun and Beopjeon-A ore deposits are precipitated in stage III and stage II, respectively. Mineral constituents of ores from these deposits are pyrite, sphalerite, arsenopyrite, pyrrhotite, chalcopyrite, galena, tetrahedrite, electrum, quartz and rhodochrosite. Cubanite, argentite and pyrargyrite occur only in Deogheun ore deposits. Ag content of electrum range from 42 to 66 atomic % in both ore deposits. Filling temperature of fluid inclusion from both ore deposits are as follows; stage I, $211-289^{\circ}$ ; stage II, $205-290^{\circ}$ ; stage III, $190-260^{\circ}$ ; stage IV, $136-222^{\circ}$ in Deogheun ore deposits. In Beopjeon-A ore deposits, stage I, $255-305^{\circ}$ ; stage II, $135-222^{\circ}$ ; stage III, $148-256^{\circ}$ ; stage IV, $103-134^{\circ}$. Salinities of fluid inclusions range from 1.6-8.5 wt. % equivalent NaCl in both ore deposits. Sulfur fugacities through stage II and III in Deogheun ore deposits inferred from data of mineral assemblage and fluid inclusion range from $10^{-11.0}-10^{-16.1}$1bars. Fluid pressure estimated from fluid inclusions which reveal boiling evidence range from 30-190 bars during mineralization in Deogheun ore deposits.

• Economic and Environmental Geology
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• v.31 no.1
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• pp.1-10
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• 1998

Copper mineralization of the Donghwa and Hwanghagsan mines was deposited in hydrothermal quartz veins which filled fissures in Cretacous sedimentary rocks. Ore minerals are pyrite, sphalerite, chalcopyrite, bornite, galena, wittichenite and unidentified Cu-Bi-Pb-Sb-S mineral. On the basis of salinities and homogenization temperatures for fluid inclusions, the Donghwa deposit was deposited from $300^{\circ}C$ to $220^{\circ}C$ with 2.5 to 0.2 wt.% eq. NaCl, and the Hwanghagsan deposits was deposited from $300^{\circ}C$ to $160^{\circ}C$ with 4.0 to 0.0 wt.% eq. NaCl. Evidence of boiling suggests pressure of 170 to 60 bar, these pressures correspond to 1700 m to 600 m. The ${\delta}^{34}S_{H_2S}$ values of the Donghwa deposit (4.8~7.4%) are higher than those of the Hwanghagsan deposit (3.5~4.5%), sulfur isotope compositions indicate that ore fluids partially reacted with meteoric water and wall-rock. Equilibrium thermodynamic interpretation indicates that the temperature versus $fs_2$ of the Donghwa deposit (> $420^{\circ}C$, $10^{-3.2}atm$) is higher condition than that of the Hwanghagsan deposit (> $290^{\circ}C$, $10^{-7.0}atm$). K-Ar ages for biotite granite and quartz porphyry in the study area are 64.7 Ma, and 60.9 Ma, reapectively. Mineralization age using sericite in the Donghwa deposits is 59.8 Ma. Therfore, Copper mineralization in the study area was associated with acidic igneous activity such as biotite granite or quartz porphyry.

• Economic and Environmental Geology
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• v.29 no.2
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• pp.139-150
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• 1996

The Yucheon Bi deposits at Cheongha, Gyeongsangbugdo, is of a middle Paleogene (49 Ma) vein type, and is hosted in sandstone and shale of Banyawal formation in Cretaceous age. Based on mineral paragenesis, vein structure and mineral assemblages, two minera1ization stages were distinguished. The stage I consists of quartz with small amount of chlorite, pyrite, epidote, hal1oysite, vermiculite, serpentine and rutile associated with sericitization. The stage II is characterized by Bi minera1ization such as bismuthinite, Bi-Cu-Pb-S mineral, tetradymite, native gold, pyrite, pyrrhotite, arsenopyrite, wolframite, rutile, hematite, sphalerite, chalcopyrite, galena with alteration of sericite, chlorite, K-feldspar, albite and epidote. Fluid inclusion data indicate that fluid temperature and NaCl equivalent wt.% salinity range from 431 to $150^{\circ}C$ and from 19.2 to 0.18wt.% in the stage II. Evidence of boiling during the base-metal minera1ization indicates pressures 241 to 260 bars. Sulfur fugacity($-log\;f_{S2}$) deduced by mineral assemblages and compositions ranges from 5.1 to 5.7atm in early stage, from > 8.4 atm in middle stage and from 13.5 to 19.3 atm in late stage. It suggests that complex histories of progressive coo1ing, dilution and boiling were occurred by the mixing of the fluids. The ${\delta}^{34}S$, ${\delta}^{18}O$ and ${\delta}D$ data range from 2.5 to 3.9%, -0.5 to -4.1% and -29.7 to -47%, respectively. It indicated that hydrothermal fluids may be magmatic origin with boiling and mixing of meteoric water increasing paragenetic time.

• Economic and Environmental Geology
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• v.28 no.4
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• pp.389-394
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• 1995

Yugu-Kwangcheon Au-Ag Province is connected to the southwestern part of the Cheonan Province and includes the Gubong (one of the biggest gold mine in past), Daebong and Samgwang mines. Cadmium concentrations in sphalerite of Yugu-Kwancheon Province is higher than those of other Au-Ag provinces and could be the source of the heavy metal contaminations. Heavy metals are present in rock-soil-plant-human system from natural geological materials, and dietary intake through this system makes a significant contribution to the ingestion of heavy metals by man. In order to examine the degree and extent of heavy metal contaminations in the Gubong, Daebong and Samgwang mine areas of Yugu-Kwangcheon Province, soil, stream water, sediment and crop plant samples were taken and analyzed for Cd, Cu, Pb and Zn by Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Cadmium and Pb concentrations in paddy/farm soils and stream sediments from the Gubong and Samgwang mine areas are higher than those in uncontaminated soils. Lead concentrations in crop plants cultivated in these soils are high up to $0.38{\mu}g/g$ in rice grain and $4.5{\mu}g/g$ in sesame. In these mine areas, regular consumption of crop plants by the local population would seem to pose a potential health problems from long-term Pb exposure. The biological absorption coefficient in rice grain for heavy metals varies in the order $C_d=Zn>Cu>Pb$ and the relationship between Cd concentrations in soils and crop plants is expressed by the equation $Cd_{plant}=0.11245\;Log\;Cd_{soil}+0.13472$.

• Economic and Environmental Geology
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• v.15 no.4
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• pp.221-233
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• 1982

Ssangjeon tungsten ore deposits is a complex pegmatite deposits embedded along the contact between pre-Cambrian Buncheon granite gneiss and amphibolite. This pegmatite vein developed 2 km along the strike and thickness varies from 10m to 40m. Mineral constituent of the normal pegmatite are quartz, microcline, plagioclase, muscovite, biotite, tourmaline and garnet. The vein paragenesis is complicated by repeated deposition of quartz but three distinct depositional stage can be recognized. Quartz A stage is the stage of the earliest milky white quartz deposition as a rock forming mineral of normal pegmatite. Quartz B stage is the stage of gray to dark gray quartz replace earlier formed normal pegmatite minerals. Quartz C stage is the stage of latest white translucent massive quartz replace quartz A and B. Tungsten ore minerals and other sulfide minerals were precipitated during quartz B stage. Ore minerals are ferberite and scheelite. Minor amount of molybdenite, arsenopyrite, pyrrhotite, pyrite, chalcopyrite, sphalerite, galena, pentlandite, bismuthinite, native bismuth and marcasite accompanied. Fluid inclusion in quartz A and B are gaseous inclusions and liquid inclusions are contained in quartz C as a primary inclusions. Salinity of inclusions in quartz A and B ranges from 4.5 to 9.5 wt. % and from 5.1 to 6.0 wt. % equivalent NaCl respectively. Homogenization temperature of quartz A; quartz B and quartz C ranges from 415 to $465^{\circ}C$, from 397 to $441^{\circ}C$ and from 278 to $357^{\circ}C$. $CO_2$ content of the ore fluid increased at the ends of quartz B stage.

• Economic and Environmental Geology
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• v.3 no.4
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• pp.199-222
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• 1970

One of the biggest sulfide metallic (Cu, Pb, Zn) ore deposits of South Korea is located in the area of Seo-myeon, Shiheung-gun, Gyeonggi-do. Geology of the region is mostly composed of metasediments of biotite schist, graphite schist, injection gneiss, sericite schist, limesilicate and quartzite from bottom, those are applicable to so-called Yeoncheon System of Pre-Cambrian, and granodiorite, quartz porphyry, basic dykes are outcroped in a small scope as intrusives. The origin of the ore deposit is pyrometasomatic contact deposits due to hydrothermal replacement and the ore bodies are imbedded in lower bed of limesilicate formation as impregnation and ore minerals are galena, sphalerite, marmatite, chalcopyrite, bornite, chalcocite, covellite, and the later two minerals are both hypogene and supergene. Gangue minerals are mostly skarn minerals those hornblende, diopside, epidote, hedenbergite, chlorite, garnet and quartz except primary calcite and quartz. Boundary plane (NS strike) between schists and limesilicate seemed to be primary opening of ore solution and fractures bearing $N50^{\circ}{\sim}80^{\circ}W$ are secondary structural control for localization of ore minerals and the third structural controls are both irregular gashes and schistosity in small scale. Photogeological study was carried with vertical aerial photo scaled 1: 38,000 and enlarged 1 : 10,000 under stereoscope. The study on the area convinced the fact that the geologic boundaries between rocks, limesilicates and quartzites, are traced easily by their typical topographic feature and drainage, and the main fracture patterns which derived from the result of fracture traces, that photogeologic lineament observed under stereoscope, are those bearing (1) $N20^{\circ}W$, (2) $N58^{\circ}W$, (3) $N76^{\circ}W$, (4) EW, (5) $N20^{\circ}W$, (6) $N62^{\circ}W$, (7) $N77^{\circ}W$. Among the written fractures, (5) (not schistosity, in case of fault) (6) (7) are post-mineral faults and others are pre-mineral faults and others are pre-mineral structures, and (2) (3) (6) (7) are coincided with statistical figure of 208 fractures surveyed in underground. By the result of the study, mineralized zone, are presumed to extend north and southward, total length about 4km.

• Journal of the Mineralogical Society of Korea
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• v.19 no.3 s.49
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• pp.139-151
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• 2006

Base metal sulfides occur in the Huronian sedimentary rocks that cover the Archean volcanic rocks in the Cobalt area, Ontario, Canada. They are mostly concentrated in the basal conglomerate which was formed in the pre-Huronian basin structure. Sulfide occurrence can be grouped as massive sulfide clasts in the basal and Coleman conglomerate, disseminated sulfides throughout the sediments, and disseminated sulfides near Ag-Co-Ni-As carbonate veins. Detrital mechanism can explain features such as angularity of sulfide fragments and graded bedding of dissemnated sulfides. Sulfides concentrated near carbonate veins are probably of hydrothermal origin. Nearby strata-bound type massive sulfide ore deposits and mineralized interflow units are the most probable sources for syngenetic sulfides. This is supported by the angularity of sulfide fragments, presence of massive sulfide boulders which are identical in mineralogy and texture to the strata-bound type sulfide deposits in the Archean basement, and a similar composition of sphalerite in the Archean volcanic rocks and Huronian sedimentary rocks. Some sulfide grains, especially in sandstones and argillites, were undergone recrystallization during the intrusion of the Nipissing diabase.

• Economic and Environmental Geology
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• v.22 no.3
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• pp.237-252
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• 1989

The Inseong gold-silver mine is located 3Km northwest of Suanbo, Choongcheongbugdo, Republic of Korea. The mine occurs in the shear zone formed by tension fractures within the Hwanggangri Formation of the Ogcheon metamorphic belt. Ore minerals found in the gold-silver bearing hydrothermal quartz vein composed mainly of pyrite, arsenopyrite, sphalerite, galena and minor amount of chalcopyrite, pyrrhotite, stannite, bismuthininte, native bismuth, chalcocite, electrum and tellurian canfieldite(?). The gangue minerals are quartz, calcite, chlorite and rhodochrocite. Wallrock alterations such as chloritization, silicitication, pyritization, carbonitization and sericitization can be observed in or around the quartz vein. According to the paragenetic sequence, quartz vein structure and mineral assemnlages, three different stages of ore formation can be recognized. The physico-chemical environment of ore formation in this deposit shows slight variation from stage to stage, but the condition of main ore deposition can be summarized as follows. Fluid inclusion, S-istope geothermometry and geothermometry based on mineral chemistry by use of arsenopyrite and chlorite show the ore was formed at temperature between 399 and $210^{\circ}C$ from fluids with salinities of 3.3-5.8 wt.% equivalent NaCl. It indicates that pressure during the mineralization is less than 0.6 Kb corresponding to a depth not greater than 1Km. S-isotope data suggests that thermal fluid may have magmatic origin wit some degree of mixing with meteoric water. In coclusion, the Inseong gold-silver deposit was formed at shallow depth and relatively high-temperature possibly with steep geothermal gradient under xenothermal condition.