• Journal of the Mineralogical Society of Korea
• /
• v.21 no.1
• /
• pp.1-15
• /
• 2008

The Cretaceous Gajok gold-silver deposit within porphyry granite is located nearby the Cretaceous Pungam basin at the northeastern area in Republic of Korea. The Gajok gold-silver deposit is distinctively composed of a multiple-complex hydrothermal veins with comb, crustiform chalcedony quartz and vug textures, implying it was formed relatively shallower depth. The hypogene open-space filling veins could be divided into 5 paragenetic sequences, increasing tendency of Ag-rich electrum and Ag-phases with increasing paragenetic time. Electrum with high gold contents (${\sim}50$ atomic % Au) as well as sphalerite with high FeS contents (${\sim}6$ mole % FeS) are representative ore minerals in the middle stage. The late stage is characterized by silver-phase such like native silver and/or argentite, coexisting with Ag-rich electrum ($10{\sim}30$ atomic % Au) and Fe-poor sphalerite (< 1 mole % FeS). The ore-forming fluids evolution started at relatively high temperature and salinity (${\sim}360^{\circ}C$, ${\sim}7\;wt.%$ eq. NaCl) and were evolved by dilution and mixing mechanisms on the basis of fluid inclusion study. The gold-silver mineralization proceeded from ore-forming fluids containing greater amounts of less-evolved meteoric waters(${\delta}^{18}O$; $-0.6{\sim}-6.7\;%o$). These results imply that gold-silver mineralization of the Cretaceous Gaiok deposit formed at shallow-crustal level and could be categorized into low-sulfidation epithermal type, related to Cretaceous igneous activity.

• The Journal of Society for e-Business Studies
• /
• v.23 no.3
• /
• pp.13-32
• /
• 2018

Btcoin has made a big progress through anonymity, decentralized authority, sharing economy, multi-ledger book-keeping, block-technology and the convenient financial vehicle. Bitcoin has the characteristics of mining and supply by decentralized suppliers, limited supply quantity and the partial money-like function as well as gold. The paper studies the hedge and safe-haven of Bitcoin and gold on daily frequency data over the period of July 20, 2010-Dec. 27, 2017 employing Asymmetric Vector GARCH. It finds that gold has the hedge and safe-haven against inflation and capital markets while Bitcoin has the weak hedge and the weak safe-haven. It shows insignificant effects of inflations of US and Korea on the volatilities of Bitcoin and gold. It also suggests the necessity of clearing of vagueness behind the anonymity for fair and transparent trade through the law application in the absence or fault in law (Lucken im Recht). following the spirit of the living constitution (lebendige gutes Recht oder Vorschrift). The relevant institutions are hoped to be given some of obligations such as registration, minimum required capital. report, disclosure, explanation, compliance and governance with autonomous corresponding rights. The study also suggests the reestablishment of the relevant financial law and taxation law. The hedge would not be successfully accomplished without the vigilant cautions of investors.

• Journal of Soil and Groundwater Environment
• /
• v.23 no.5
• /
• pp.17-25
• /
• 2018

The Boroo area in Mongolia is known to have been contaminated with heavy metals due to irregular gold mining activities and the release of mercury from gold extraction process. Soil and mine tailings were collected to analyze contamination patterns of heavy metals in the Boroo area. Analyses revealed that mercury, arsenic and cadmium concentrations exceeded the regulatory standard of the nation (Mongolia National Standard). In case of mercury, about 80% of the survey area was over the limit and the concentration distribution heavily influenced by influx of mercury through water transport. Soil contamination by arsenic was most severe that the concentration exceeded the regulatory limit in almost entire survey area, showing peak concentrations at nearby streams and river along with ore processing facilities. For cadmium, about 20% of the survey area was over the limit with the concentration distribution similar to that of arsenic.

• Safety and Health at Work
• /
• v.10 no.2
• /
• pp.188-195
• /
• 2019

Background: Mine workers in South Africa face challenges relating to poor health and safety, including fatigue risks, and poor socioeconomic and living conditions. Fatigue results in impaired mental and physical performance. The aim of this study was to assess contributors to fatigue of mine workers in South Africa. Methods: Data collection took place at four gold mines and one platinum mine in South Africa. A total of 21 focus groups were held with individuals in management, union representatives, and mine workers, and 564 questionnaires were completed by mine workers to gather information about fatigue and potential contributors to fatigue at these mines. Results: Qualitatively (through focus groups), fatigue was attributed to extended working hours, harsh working conditions, high workloads, production pressure, and resource constraints, along with aspects relating to demographic and socioeconomic factors, living conditions, lifestyle, health, and wellness. Greater fatigue was significantly associated with younger age, indebtedness, a lack of exercise, poor nutrition, less sleep, increased alcohol use, poor self-reported health, more sick leave, higher stress, and lower job satisfaction. Conclusion: The aim of the study was achieved; numerous work-, sociodemographic-, lifestyle-, and wellness-related factors were linked to fatigue in the participating mine workers. Contributors to fatigue should be addressed to improve health, safety, and sustainability in the industry.

• Economic and Environmental Geology
• /
• v.21 no.3
• /
• pp.269-276
• /
• 1988

Ore deposits of Dadeok mine, the largest in the Bonghwa gold mining district, are composed of numerous gold and silver-bearing quartz veins emplaced in granite batholith. Mineralization of the Pungjeong vein, one of the representative vein in the mine was investigated. K-Ar age of sericite in the vein is $84{\pm}5$ Ma. Hypogene 6pen-space filling can be devided into four paragenetic stages; (1) fine grained quartz and carbonate; (2) quartz and carbonates with base metal sulfides, electrum, native silver, argentite, polybasite, freibergite, pyrargyrite, and Cu-Ag-Fe-S minerals; (3) quartz with base metal sulfides; (4) quartz and calcite with or without pyrite. Composition of electrum ranges from 44.17 to 56.50 atomic % Ag. Meanwhile FeS content of sphalerite coexisting with elctrum in stage II range from 0.01 to 1.67 mol. %. Homogenization temperatures for quartz and sphalerite of stage II ($239^{\circ}$ to $310^{\circ}C$), quartz of stage III ($206^{\circ}$ to $255^{\circ}C$) and quartz and calcite of stage IV ($232^{\circ}$ to $253^{\circ}C$) show little time-space variation during mineralization. Salinities of the fluid inclusions range from 5.5 to 12.8wt% NaCI in stage II, 7.3 to 12.3wt% in stage III and 4.5 to 8.0wt% in stage IV. Based on the homogenization temperatures, Fe content of sphalerite and Ag content of electrum, tempera ture and sulfur fugacity for stage II are estimated to be $208^{\circ}$ to $310^{\circ}C$ and $10^{-9.2}-10^{-12.8}$ bars, respectively.

• Ocean and Polar Research
• /
• v.23 no.1
• /
• pp.51-62
• /
• 2001

The Arctic consists of numerous sedimentary basins containing voluminous natural resources and two of the world's major oil and gas producing areas. The western Siberia Basin in the Arctic region has the largest petroliferous province with an area of 800 ${\times}$ 1,200 km and produces more than 60% of total Russian oil production. The North Slope of Alaska produces about 20% of the U.S. output, i.e., 11% of the total U.S. consumption. Being small compared to those regions, the Canadian Northwest Territories and the Pechora Basin in Russia produce only fair amount of oil and natural gas. There are also many promising areas in the northern continental shelf of Russia. In addition to Russia, Svalbard and Greenland have been investigated for oil and gas. Gas hydrates are widespread in both permafrost regions and arctic continental shelf areas. The reserves of gas hydrates in the Arctic Ocean are about 20${\sim}$32% of total estimated amounts of gas hydrates in the world ocean. Mineral mining is well developed, especially in Russia. The major centers are located around the Kuznetsk Basin and Noril'sk. They are major suppliers of gold, tin, nickel, copper, platinum, cobalt, iron ore, coal as well as apatite. There are also some minings of lead-zinc in Alaska and Arctic Canada.

• Economic and Environmental Geology
• /
• v.31 no.5
• /
• pp.389-398
• /
• 1998

The Au-Ag deposit of the Oknam mine occurs as gold-silver-bearing rhodochrosite veins in biotite schist and phyllite of the Precambriam Yulri Group. Five stages of ore deposition are recognized, each showing a definite mineral assemblage. General mineral parageneses in veins (stage III) associated with gold and silver vary inwardly from the vein margin: arsenopyrite + pyrite $\Rightarrow$ sphalerite+chalcopyrite+galena+gold $\Rightarrow$ ga1ena+Ag-bearing minerals. Fluid inclusion data indicate that temperature and salinity of ore fluids overally decreased with time: $345^{\circ}{\sim}240^{\circ}C$ and 3.4~7.8 wt. % NaCl equiv during stage I (quartz vein mineralization), $313^{\circ}{\sim}207^{\circ}C$ and 2.3~8.7 wt.% NaCl equiv during manganese-bearing carbonate stages (II and III), and $328^{\circ}{\sim}213^{\circ}C$ and 3.6-5.4 wt.% NaCl equiv during stage IV (quartz vein mineralization). The ore fluids probably evolved through repeated pulses of boiling and later mixing with cooler and more dilute meteoric waters. Fluid inclusion data and geologic arguments indicate that pressures during the mineralization were in the range of 90 to 340 bars. Gold occurs as silver-rich electrums (21 to 29 atom. % Au) and was deposited at temperatures between $300^{\circ}$ and $240^{\circ}C$. Thermochemical calculations suggest that gold was deposited as a combined result of increase in pH and decreases in temperature, $fs_2$ and $fo_2$.

• Economic and Environmental Geology
• /
• v.43 no.5
• /
• pp.491-503
• /
• 2010

Geochemical characteristics of the Moisan epithermal gold-silver deposit with total 140 samples in Haenam area, Jeollanamdo were studied by using multivariate statistical analysis (correlation analysis, factor analysis and cluster analysis). The correlation analysis reveals that Ag, Cu, Bi, Te are highly correlated with Au in the both non-mineralized and mineralized zone. It is resulted from the presence of Au-Ag bearing minerals (electrum, sylvanite, calaverite and stuezite) and non Au-Ag containing minerals (chalcopyrite, tellurobismuthite and bismuthinite). Mo shows relatively much higher correlation at the mineralized zone (0.615) than non-mineralized zone (0.269) which implies Mo content is strongly affected by Au-mineralization. While Mn, Cs, Fe, Se correlated with Au at the nonmineralized zone, they have negative correlation at the mineralized zone. Therefore, they seem to be eluviated elements from the host rock during gold mineralization. Sb is enriched during the gold mineralization showing high correlation at the mineralized zone and negative correlation at the non-mineralized zone. According to the factor analysis, Se, Ag, Cs, Te are the indicators of gold mineralization presence due to the strong affection of gold content in the non-mineralized zone. In the mineralized zone, on the other hand, Mo, Te and Sb, Cu are the indicators of gold and silver mineralization, respectively. While the cluster analysis reveals that Cd-Zn-Pb-S, Bi-Fe-Cu-Mn, Se-Te-Au-Cs-Ag, As-Sb-Ba are the similar behavior elements groups in the non-mineralized zone, Cd-Zn-Mn-Pb, Fe-S-Se, As-Bi-Cs, Ag-Sb-Cu, Au-Te-Mo are the similar behavior elements groups in the mineralized zone. Using multivariate statistical analysis as mentioned above makes it possible to compare the behavior of presented minerals and difference of geochemical characteristics between mineralized and non-mineralized zone. Therefore, it will be expected a useful tool on the similar type of mining exploration.

• Economic and Environmental Geology
• /
• v.38 no.6 s.175
• /
• pp.663-673
• /
• 2005

This study investigates the relationship between the geochemical maps and the gold-silver deposit locations. Geochemical maps of 21 elements, which are published by KIGAM, locations of gold-silver deposits, and 1:1,000,000 scale geological map of Korea are utilized far this investigation. Pixel size of the basic geochemical maps is 250m and these data are resampled in 1km spacing for the statistical analyses. Relationship between the mine location and the geochemical data are investigated using bayesian statistics and decision tree algorithms. For the bayesian statistics, each geochemical maps are reclassified by percentile divisions which divides the data by 5, 25, 50, 75, 95, and $100\%$ data groups. Number of mine locations in these divisions are counted and the probabilities are calculated. Posterior probabilities of each pixel are calculated using the probability of 21 geochemical maps and the geological map. A prediction map of the mining locations is made by plotting the posterior probability. The input parameters for the decision tree construction are 21 geochemical elements and lithology, and the output parameters are 5 types of mines (Ag/Au, Cu, Fe, Pb/Zn, W) and absence of the mine. The locations for the absence of the mine are selected by resampling the overall area by 1 km spacing and eliminating my resampled points, which is in 750m distance from mine locations. A prediction map of each mine area is produced by applying the decision tree to every pixels. The prediction by Bayesian method is slightly better than the decision tree. However both prediction maps show reasonable match with the input mine locations. We interpret that such match indicate the rules produced by both methods are reasonable and therefore the geochemical data has strong relations with the mine locations. This implies that the geochemical rules could be used as background values oi mine locations, therefore could be used for evaluation of mine contamination. Bayesian statistics indicated that the probability of Au/Ag deposit increases as CaO, Cu, MgO, MnO, Pb and Li increases, and Zr decreases.

• Economic and Environmental Geology
• /
• v.22 no.3
• /
• pp.193-205
• /
• 1989

Regional geology of Chungil mine is composed of Cretaceous biotite granite. Chungil ore deposits are fissure filled quartz veins which developed in Cretaceous biotite granites. Mineralogic and fluid inclusion studies were undertaken to illuminate the origin of the ore deposits. Data gathered from occurrences of ore deposits and mineral paragenesis reveals that there were two major mineralization stage. The first stage is sulfides-quartz stage. The constituents of ore minerals are chalcopyrite, sphalerite, pyrrhotite with minor amount of galena, native Au, Ag, pyrite. The second stage is gangue mineral stage. Gangue minerals are quartz, fluorite and calcite. Homogenization temperature of fluid inclusions in quartz of the first and the second stage ranges from $212^{\circ}C$ to $336^{\circ}C$ and from $154^{\circ}C$ to $355^{\circ}C$ respectively. Homogenization temperature in fluorite and calcite of the second stage ranges from $127^{\circ}C$ to $252^{\circ}C$ and from $129^{\circ}C$ to $158^{\circ}C$ but these data require positive pressure corrections. Fluid inclusions in quartz of the Bongmyeong mine, Jangja the first mine and the second mine show range of homogenization temperature from $178^{\circ}C$ to $330^{\circ}C$, from $185^{\circ}C$ to $354^{\circ}C$ and from $206^{\circ}C$ to 336 respectively. The comparison of the fluid inclusion data, mineralogical component and vein attitude of the three mines with that of Chungil mine indicates that the origin of the deposits above mentioned is elucidated to be formed under similar environment. The compositions of the sphalerite in the first stage range from 16.05 mol.% FeS to 20.36 mol.% FeS.