• Economic and Environmental Geology
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• v.21 no.4
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• pp.367-380
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• 1988

Most of the gold (-silver) vein deposits at Yeongdong District are mainly distributed in the precambrian metamorphic rocks. Based on the Ag/Au total production and ore grade ratios, the chemical composition of electrum and the associated sulfides, the gold(-silver) deposits at Yeongdong District may be classified into 4 classes: pyrrhotite - type gold deposits( I), pyrite - type gold deposits (IT A; massive vein), pyrite - type gold deposits (II B; nonmassive vein) and argentite - type gold - silver deposits(III). The chemical study on electrum(including native gold) revealed that Au content (2.8 to 92.4 atomic%) of electrums varies very widely for different classes of deposits. The Au content of electrum associated with pyrrhotite (Class I), ranging from 47.1 to 92.4 atomic% Au, is clearly higher than that associated with pyrite (Classes IIA, IIB and III). In contrast, classes I, II, and III deposits do not show clear differences in Au content of electrum. In general, pyrrhotite - type gold deposits(I) are characterized by features such as simply massive vein morphology, low values in the Ag/Au total production and ore grade ratios, the absence or rarity of silver - bearing minerals except electrum, and distinctively simple mineralogy. Although the geological and mineralogical features and vein morphology of pyrite - type gold deposits(IIA)are very similar to those of pyrrhotite - type gold deposits (I), Class II A deposits reveal significant differences in the associated iron sulfide (i. e. pyrite) with electrum and Au content of electrum. The Ag/Au total production and ore grade ratios from Class II A deposits are relatively slightly higher than those from Class I deposits. Pyrite - type gold deposits(II B) and argentite - type gold - silver deposits (III) have many common features; complex vein morphology, medium to high values in the Ag/Au total production and ore grade ratios and the associated iron sulfide (i. e. pyrite). In contrast to Class II B deposits, Class III deposits have significantly high Ag/Au total production and ore grade ratios. It indicates distinct difference in the abundance of silver minerals (i. e. native silver and argentite). The fluid inclusion analyses and mineralogical data of electrum tarnish method indicate that the gold mineralization of Classes I and II A deposits was deposited at temperatures between $230^{\circ}$ and $370^{\circ}C$, whereas the gold (-silver) mineralization of Classes ITB and ill formed from the temperature range of $150^{\circ}-290^{\circ}C$. Therefore, Classes I and IT A deposits have been formed at higher temperature condition and/or deeper positions than Classes IIB and III.

• Advances in nano research
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• v.1 no.4
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• pp.219-228
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• 2013

We report on the preparation of iron pyrite ($FeS_2$) using pulsed electron ablation of two targets, namely, a mixture of sulfur and iron compound target, and a natural iron pyrite target. Thin films of around 50 nm in thickness have been deposited on glass substrates under Argon background gas at 3 mTorr, and at a substrate temperature of up to $450^{\circ}C$. The thin films have been analyzed chemically and examined structurally using x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and visible Raman spectroscopy. The morphology and thickness of the films have been assessed using scanning electron microscopy (SEM) and visible spectroscopic reflectance. The preliminary findings, using a synthetic target, show the presence of iron pyrite with increasing proportion as substrate temperature is increased from $150^{\circ}C$ to $250^{\circ}C$. The data have not shown any evidence of pyrite in the deposited films from a natural target.

• Journal of the Mineralogical Society of Korea
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• v.13 no.3
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• pp.115-120
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• 2000

Oxidation of pyrite has caused a serious environmental problem such as the acidification of soil and surface water. The mineralogical change of acid sulfate weathering of hydrothermally altered andesite which contained 11.8% of pyrite and was exposed in atmosphere by lay out works for a residential area and a golf course was studied using X-ray diffraction (XRD) and electronmicroscopes. Ferrihydrite, jarosite, and an unidentified water soluble phase were observed as weathering products of the andesite. Under electronmicroscopes, showed aggregate of platy microcrystals; jarosite was platy morphology: water soluble Phase was columnar. Morphology of fresh Pyrite in the andesite changed from pyritrohedron to cubic in its frequency with increasing its particle size. The drainage water was acidic (pH 3.5) and in an equilibrium state with both ferrihydrite and jarosite.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.311-317
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• 2000

Acid sulfate soil and potential acid sulfate soil material are worldwide in distribution and are problematic in agriculture and environment due to their present and potential acidity developed by the oxidation of sulfides. Most of them are sedimentary origin and a few cases are reported as volcanic or metamorphic origin. We report a potential acid sulfate soil material originated from volcanic activity during Mesozoic. A profile of Bongsan series-weathered nonpyritic andesite-hydrothermally altered pyrite rich andesite was studied with field examination, chemistry, and mineralogy. Once, the pyrite rich andesite was exposed to atmosphere by excavation and leveling works for a residential area and the lay out site had subsequent acidification problem of soil and surface water. The parent material and soil profile of Bongsan series had no signs of presence of pyrite and acid sulfate weathering such as yellow mottles. However, the hydrothermally altered andesite substrata contained significant amount of pyrite showing characteristics of hydrothermal origin such as cubic and pyritohedron morphology and occurrence along cracks.

• Journal of Acupuncture Research
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• v.26 no.5
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• pp.65-75
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• 2009

Objectives : Pyrite is one of the important prescriptions that has been used in oriental medicine for healing of fracture. It is reasonable, therefore, to postulate that native copper affects the process of bone metabolism and bone formation. The purpose of this study is to discover the effect of Pyrite on the healing of tibia fracture. Methods : 1. In vitro test : MG-63 cell in human body and the Pyritum in the ratio of 0.5mg/ml, 1.0mg/ml, 1.5mg/ml, 2.0mg/ml were incubated for 24 hours. After 24 hours, RNA was extracted via trizol reagent (Sigma, USA). In order to understand the activation of osteoblast, the level of OPN mRNA, osteopontin, was measured. 2. In vivo tesgroups normal group, control group and experimental group. Left tibia bones of mice in CON and JT groups were fractured by bone cutters. Pyrite was orally administered to the experimental group. After 14 days, each group's tibia specimen was constructed to observe changes in activation of proinflmmatory cytokines in relation to MIF and IL-6. Also, proliferation of osteoblast and osteopontin were measured via changes in levels of OPN and OPN mRNA. Results : In jn-Titro test, the level of OPN mRNA, osteopontin production was remarkably increased in Pyritum-treated MG-63 cells. In in-vitro test, fractured area in external tibia morphology was increased more in the JT group than that of the CON group. Osteogenesis, endochodrial ossification, and osteoid in fractured area were also increased more in the JT group than that of the CON group. Increase in OPN mRNA, osteopontin level and osteoblast's proliferation were observed. Activation of MIF and IL-6 was confirmed from the fracture region. Conclusions : From the result, development of a new stimulator in healing fracture via pyrite is expected.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.10a
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• pp.119-136
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• 2002

Contrasts in the style of the gold-silver mineralization in geologic and tectonic settings in Korea, together with radiometric age data, reflect the genetically different nature of hydrothermal activities, coinciding with the emplacement age and depth of Mesozoic magmatic activities. It represents a clear distinction between the plutonic settings of the Jurassic Daebo orogeny and the subvolcanic environments of the Cretaceous Bulgugsa igneous activities. During the Daebo igneous activities (c.a. 200-150 (?) Ma) coincident with orogenic time, gold mineralization took place between c.a. 195 and 135 (127 ?) Ma. The Jurassic Au deposits commonly show several characteristics; prominent association with pegmatites, low Ag/hu ratios in the ore-concentrating parts, massive vein morphology and a distinctively simple mineralogy including Fe-rich sphalerite, galena, chalcopyrite, arsenopyrite, Au-rich electrum, pyrrhotite and/or pyrite. During the Bulgugsa igneous activities $(110\~50Ma)$, the precious-metal deposits are generally characterized by such features as complex vein morphology, medium to high AE/AU ratios in the ore concentrates, and diversity of ore minerals including base-metal sulfides, pyrite, arsenopyrite, Ag-rich electrum and native silver nth Ag sulfides, Ag-Sb-As sulfosalts and Ag tellurides. Vein morphology, mineralogical, fluid inclusion and stable isotope results indicate the diverse genetic natures of hydrothermal systems in Korea. The Jurassic Au-dominant deposits (orogenic type) were formed at the relatively high temperature $(about\;300^{\circ}\;to\;450^{\circ}C)$ and deep-crustal level $(4.0{\pm}1.5\;kb)$ from the hydrothermal fluids containing more amounts of magmatic waters $(\delta\;^{18}O_{H2O}\;5\~10\%_{\circ})$. It can. It can be explained by the dominant ore-depositing mechanisms as $CO_2$ boiling and sulfidation, suggestive of hypo- to mesothermal environments. In contrast, the Cretaceous Au-dominant $(l13\~68\;Ma),\;Au-Ag \;(108\~47\;Ma)$ and Ag-dominant $(103\~45\;Ma)$ deposits, which correspond to volcanic-plutonic-related type, occurred at relatively low temperature $(about\;200^{\circ}\;to\;350^{\circ}C)$ and shallow-crustal level $(1.0\{pm}0.5\;kb)$ from the ore-forming fluids containing more amounts of less-evolved meteoric waters$(\delta\;^{18}O_{H2O}\;-10\~5\%_{\circ})$. These characteristics of the Cretaceous precious-metal deposits can be attributed to the complexities in the ore-precipitating mechanisms (mixing, boiling, cooling), suggestive of epi- to mesothermal environments. Therefore, the differences of the emplacement depth between the Daebo and the Bulgugsa igneous activities directly influence the unique temporal and spatial association of the deposit styles.

• Proceedings of the KSEEG Conference
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• 2002.10a
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• pp.119-136
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• 2002

Contrasts in the style of the gold-silver mineralization in geologic and tectonic settings in Korea, together with radiometric age data, reflect the genetically different nature of hydrothermal activities, coinciding with the emplacement age and depth of Mesozoic magmatic activities. It represents a clear distinction between the plutonic settings of the Jurassic Daebo orogeny and the subvolcanic environments of the Cretaceous Bulgugsa igneous activities. Dunng the Daebo igneous activities (c.a. 200～150 (\ulcorner) Ma) coincident with orogenic time, gold mineralization took place between c.a. 195 and 135 (127 \ulcorner) Ma. The Jurassic Au deposits commonly show several characteristics; prominent association with pegmatites, low Ag/Au ratios In the ore-concentrating parts, massive vein morphology and a distinctively simple mineralogy including Fe-rich sphalerite, galena, chalcopyrite, arsenopyrite, Au-rich electrum, pyrrhotite and/or pyrite. During the Bulgugsa igneous activities (110～50 Ma), the precious-metal deposits are generally characterized by such features as complex vein morphology, medium to high Ag/Au ratios in the ore concentrates, and diversity of ore minerals including base-metal sulfides, pyrite, arsenopyrite, Ag-rich eletrum and native silver with Ag sulfides, Ag-Sb-As sulfosalts and he tellurides. Vein morphology, mineralogical, fluid inclusion and stable isotope results indicate the diverse genetic natures of hydrothermal systems in Korea. The Jurassic Au-dominant deposits (orogenic type) were formed at the relatively high temperature (about 300$^{\circ}$ to 45$0^{\circ}C$) and deep-crustal level (4.0$\pm$1.5 kb) from the hydrothermal fluids containing more amounts of magmatic waters ($\delta$$^{18}$ $O_{H2O}$; 5～10$\textperthousand$). It can be explained by the dominant ore-depositing mechanisms as $CO_2$ boiling and sulfidation, suggestive of hypo- to mesothermal environments. In contrast, the Cretaceous Au-dominant (l13～68 Ma), Au-Ag (108～47 Ma) and AE-dominant (103～45 Ma) deposits, which correspond to volcanic-plutonic-related type, occurred at relatively low temperature (about 200$^{\circ}$ to 35$0^{\circ}C$) and shallow-crustal level (1.0$\pm$0.5 kb) from the ore-forming fluids containing more amounts of less-evolved meteonc waters ($\delta$$^{18}$ $O_{H2O}$;-10～5$\textperthousand$). These characteristics of the Cretaceous precious-metal deposits can be attributed to the complekities in the ore-precipitating mechanisms (mixing, boiling, cooling), suggestive of epi- to mesothermal environments. Therefore, the differences of the emplacement depth between the Daebo and the Bulgugsa igneous activities directly influence the unique temporal and spatial association of the deposit styles.les.

• Economic and Environmental Geology
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• v.21 no.3
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• pp.223-234
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• 1988

A large number of gold and/or silver-bearing quartz veins occur in or near Mesozoic granite batholith elongated in a NE-SW direction within the Chungcheong Province. Precambrian schists and gneisses, and Jurassic and Cretaceous granitic rocks serve as hosts for gold and/or silver deposits. On the basis of Ag/Au total production and ore grade ratio, 15 mines may be divided into three major groups: gold-dominant deposits, gold-silver deposits, and silver-dominant deposits. The chemical composition of electrum from skarn deposit (Geodo mine), alaskite-type deposit (Geumjeong mine) and 15 vein deposits was summarized. It was found that the Au content of electrum for vein deposits ranging from 5.2 to 86.5 is lower than that for skarn and alaskite deposits. Among 15 vein deposits, the composition of electrum associated with pyrrhotite is relatively high and has a narrow range of 40.8 to 86.5 atomic % Au, but the Au content of electrum with pyrite is in range of 5.2 to 82.8 atomic %, and is clearly lower than that with pyrrhotite. The grouping of ages for these mines indicates that gold and/or silver mineralizations occurred during two periods in the Mesozoic. Daebo igneous activities are restricted to gold mineralization in the range of 158 to 133 Ma, whereas Bulgugsa igneous activities are related to gold and/or silver mineralization ranging from 108 to 71 Ma. Generally speaking, Jurassic gold-dominant veins have many common characteristics; notably prominent association with pegmatites, simply massive vein morphology, high fineness in the ore concentrates, rarity of silver minerals, and a distinctively simple mineralogy, including sphalerite, galena, chalcopyrite, pyrrhotite and/or pyrite. Although individual deposits exhibit widely differing diversity, Cretaceous gold-silver and silver-dominant veins are characterized by features such as complex vein, low to medium fineness in the ore concentrates and abundance of silver minerals including Ag sulfosalts, Ag sulfides, Ag tellurides and native silver.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.203-210
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• 2002

In order to elucidate the growth mechanism of sulfide chimney formed as a result of seafloor hydrothermal mineralization, we carried out the mineralogical and fluid inclusion studies on the inactive, sulfide- and silica-rich chimney which has been recovered from a hydrothermal field in the Cleft segment of the Juan de Fuca Ridge. According to previous studies, many active and inactive vents are present in the Cleft segment. The sulfide- and silica-rich chimney is composed of amorphous silica, pyrite, sphalerite and wurtzite with minor amounts of chalcopyrite and marcasite. The interior part of the chimney is highly porous and represents a flow channel. Open spaces within chimneys are typically coated with colloform layers of amorphous silica. The FeS content of Zn-sulfides varies widely from 13.9 to 34.3 mole% with Fe-rich core and Fe-poor rims. This variation possibly reflects the change of physicochemical characteristics of hydrothermal fluids. Chemical and mineralogical compositions of the each growth zone are also varied, possibly due to a thermal gradient. Based on the microthermometric measurements of liquid-rich, two-phase inclusions in amorphous silica that was precipitated in the late stage of mineralization, minimum trapping temperatures are estimated to be about 1140 to 145$^{\circ}$C with the salinities between 3.2 and 4.8 wt.% NaCI equiv. Although the actual fluid temperatures of the vent are not available, this study suggests that the lowtemperature conditions were predominant during the mineralization in the hydrothermal field at Cleft segment. Comparing with the previously reported chimney types, the morphology, colloform texture, bulk chemistry, and a characteristic mineral assemblage (pyrite + marcasite + wurtzite + amorphous silica) of this chimney indicate that the chimney have been formed from a relatively low-temperature (<250$^{\circ}$C) hydrothermal fluid that was changed by sluggish fluid flow and conductive cooling.

• Economic and Environmental Geology
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• v.34 no.1
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• pp.25-38
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• 2001

Contrasts in the style of the gold-silver mineralization in geologic and tectonic settings in Korea, together with radiometric age data, reflect the genetically different nature of hydrothermal activities, coinciding with the emplacement age and depth of Mesozoic magmatic activities. It represents a clear distinction between the plutonic settings of the Jurassic Daebo orogeny and the subvolcanic environments of the Cretaceous Bulgugsa igneous activities. During the Daebo igneous activities (about 200-130 Ma) coincident with orogenic time, gold mineralization took place between 197 and 127 Ma. The Jurassic deposits commonly show several characteristics: prominent association with pegmatites, low Ag/Au ratios in the ore-concentrating parts, massive vein morphology and a distinctively simple mineralogy including Fe-rich sphalerite, galena, chalcopyrite, Au-rich eIectrum. pyrrhotite and/or pyrite. During the Bulgugsa igneous activities (120-60 Ma), the precious-metal deposits are generally characterized by such features as complex vein morphology, medium to high AgiAu ratios in the ore concentrates, and abundance of ore minerals including base-metal sulfides, Ag sulfides, native silver, Ag sulfosalts and Ag tellurides. Vein morphology, mineralogical, fluid inclusion and stable isotope results indicate the diverse genetic natures of hydrothermal systems. The Jurassic Au-dominant deposits were formed at the relatively high temperature (about 300 to 450$^{\circ}$C) and deep-crustal level (>3.0 kb) from the hydrothermal fluids containing more amounts of magmatic waters (3180; 5-10 %0). It can be explained by the dominant ore-depositing mechanisms as CO2 boiling and sulfidation, suggestive of hypo/mesothermal environments. In contrast, mineralization of the Cretaceous Au-Ag type (108-71 Ma) and Agdominant type (98-71 Ma) occurred at relatively low temperature (about 200 to 350$^{\circ}$C) and shallow-crustal level «1.0 kb) from the ore-fonning fluids containing more amounts of less-evolved meteoric waters (15180; -10-5%0). These characteristics of the Cretaceous precious-metal deposits can be attributed to the complexities in the ore-precipitating mechanisms (mixing, boiling, cooling), suggestive of epilmesothermal environments. Therefore, the differences of the emplacement depth between the Daebo and the Bulgugsa igneous activities directly influence the unique temporal and spatial association of the deposit type.