• Economic and Environmental Geology
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• v.22 no.1
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• pp.17-20
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• 1989

Two rhyolitic rocks were taken at punggog of the Jangseong sheet in the Taebaegsan mineralized area and isotopically dated by K-Ar whole rock method. One is a rhyolite which gives $62.69{\pm}1.15Ma$ and the other is a rhyolitic tuff which gives $51.67{\pm}6.64Ma$, respectively. Generally K-Ar whole rock ages of the volcanic rocks can be assumed to be the formation age of them, if there is no geological criterion of secondary effects. But the two rhyolitic rocks were slightly hydrothermally altered and the age the rhyolitic tuff is a little younger than that of the rhyolite. However, there is no geological criterion to show any big hiatus between them in field, yet. Therefore, the age data would be interpreted, as that the rhyolitic rock mass has been probably extruded at about 60 Ma, a little older than 60 Ma, in the area. The ages of them probably appear to be secondary ages after the alteration. This fact well coincides with the K-Ar whole rock age of quartz-porphyry ($57.25{\pm}0.89Ma$) distributed near the 1st Yeonhwa Pb-Zn mine (Park et al., personal comm.), because the quartz-porphyry look to be a product of hydrothermal alteration of the volcanic rock.

• Economic and Environmental Geology
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• v.21 no.4
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• pp.335-348
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• 1988

The author aimed to describe the volcano-stratigraphy and petrology of the volcanic mass in the Koheung peninsula, South Cheolla province. The volcanic mass is composed of the volcanics and intrusives of late Cretaceous which extruded the Pre-cambrian metamorphic(Jirisan gneiss complex) and the early Cretaceous sedimentary(Duwon Formation) basement. The volcanic pile consists of, in ascending order, Bibongsan andesite, Koheung tuff and breccia, and Palyeongsan welded tuff, and are intruded by ring intrusives( intrusive breccia, andesite porphyry, intrusive rhyolite and fine-grained quartz-diorite) and central pluton(diorite, quartz monzodiorite, biotite granite and micrographic granite). Bibongsan andesite mainly consists of andesite tuff and lava. Koheung tuff consists of alternation of fine tuff, coarse tuff and lapilli tuff, and Palyeongsan welded tuff which overlies Koheung tuff, comprises K-feldspar and quartz phenocrysts, elongated brown fiamme, lithic fragments in matrix of devitrified brown glass shards, and mainly consists of rhyodacite to rhyolite vitric ash-flow tuff. The results of petrochemical studies of the igneous rocks suggest that the rocks were a serial differentiational products of fractional crystallization of calc-alkaline magma series. This study reveals that the volcanic mass in this area is inferred to the remnant of the resurgent cauldron, measuring 30 by 25 km in diameter. The cauldron block was lowered at least 1,000 m by ring fault displacement.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.264-267
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• 2006

The purpose of this study is to examine the advertisements of eco-friendly interior products and finishing materials in 3 interior design magazines which have been published for 4 years since 2002: to identify specific types of the products and materials that consumers can choose and to analyze their special ingredients which have functions and effectiveness related to health. Literature review and content analysis on the advertisements were employed. The results are as follows: The amount of advertisements has been continuously increasing due to the public concerns on well-being and finishing material types absolutely took the greatest proportion (92.8%) among them. Floor coverings, wall papers, and paints are the big 3 materials in the finishing material advertisements. The frequently mentioned health-related ingredients in them were charcoal, natural jade, nanosilver, yellow soil and quartz porphyry, And their main functions were emission of negative ions and ultra infrared. However, it's not easy to find their scientific test results on health. Objective guidelines are needed for the right selection of interior products and materials to maintain healthy interior environment.

• Economic and Environmental Geology
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• v.10 no.2
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• pp.53-66
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• 1977

Epithermal Mn-Au-Ag deposits of subvolcanic type in the Yeongil area discovered by one (Soo Jin Kim) of the present authors was studied with emphasis on their mineralogy, genesis and future potential. Mineralization is genetically related to volcanic activities of the Tertiary Period, which have produced porphyritic rhyolite, granite porphyry, felsitic rhyolite and agglomerate. Ore deposits are closely associated with felsitic rhyolite. They occur as breccia-filling, veins, or networks. Mineralization is characterized by rhodochrosite-sulfide ores of breccia-type in the central zone, and sulfide ores of disseminated type in the outer zone. Sulfides consist mainly of pyrite and marcasite, with minor chalcopyrite, sphalerite, argentian tetrahedrite, galena and gold in the central zone, and of pyrite, marcasite and argentian tetrahedrite in the outer zone. Sulfides are generally not easily identified with naked eye because of their very fine-grained nature. Wall rock alteration zones are also developed around ore deposits over the large area. Occurrence of ore deposits and the nature of mineralization indicate that the uppermost portion of ore deposits are now exposed on the surface, and therefore, the main mineralized zones are expected in depth.

• Journal of Conservation Science
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• v.36 no.1
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• pp.60-72
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• 2020

The Inscribed stones of Hanyangdoseong has been weathered for a long time because of external environment and living organisms. To establish a long-term conservation-management strategy for the inscription stones, the material characteristics of the inscription stones of Naksan Mountain Area were identified, and its deterioration state was diagnosed. Consequently, it was confirmed that the Inscription stones of Naksan Mountain Area mainly comprised coarse-to medium-grained pinkish granite and biotite granite, and, in part, comprised reddish granite, quartz porphyry, and aplite. Presently, the Inscription stones of Naksan Mountain Area, Hanyangdoseong, is undergoing a considerable decrease in physical properties because of physical, chemical, and biological weathering. Moreover, it has been confirmed that the type of damage, such as blistering, soiling, and dicolouration, on the surface shows a significantly high deterioration rate, and that conservation treatment might be required in future. In addition, because the possibility of damage recurrence is high even after the treatment, the conservation state must be regularly monitored.

• The Journal of the Petrological Society of Korea
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• v.3 no.3
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• pp.220-233
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• 1994

The granitic rocks in the Poeun - Sogrisan area are composed of the Jurassic Poeun granodiorite and the Cretaceous Sogrisan granites. The latter can be divided into three rock types : coarse-grained biotite granite, porphritic biotite granite and granite porphyry. Petrographical observations, especially focusing on the quartz-feldspar intergrowth texture, suggest that the Sogrisan granites has emplaced at shallower level and crystallized more rapidly than the Poeun granodiorite. The F, Cl contents and the Fe/(Fe+Mg) ratio of biotite and muscovite in the Sogrisan granites are higher than those in the Poeun granodiorite. The anor-thite contents of plagioclase in the Poeun granodiorite are higher then in the Sogrisan granites. Ilmenite in the Sogrisan granites is more enriched in Mn and depleted in Fe than that in the Poeun granodiorite. The whole-rock magnetic susceptibility values (in $10^{-6}$ emu/g unit) are higher in the Sogrisan granites (33~144) than the Poeun granodiorite (9~12), indicating that the former generally belongs to magnetite-series granitoid and the latter to ilmenite-series one. The Sogrisan granites has solidified under more oxidizing environment than the Poeun gra-nodiorite, judging from the whole-rock magnetic susceptibility measurements as well as the chemical compositions of biotite and ilmenite.

• Economic and Environmental Geology
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• v.31 no.5
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• pp.375-388
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• 1998

The purpose of this study is to investigate the ore genesis and occurrence of the Wondong polymetallic mineral deposits. The Pb-Zn, Fe and W-Mo mineralizations are found in skarn zones which formed mainly in or along the fault shear zones with the $N25-40^{\circ}W$ and $N10-50^{\circ}E$ directions, whereas the Cu-Mo mineralization is appeared hydrothermal replacement zone. The skarn minerals consist mainly of garnet and epidote, which were the last alteration phases between pneumatolytic and hydrothermal stages. The mineral paragenesis toward the late stage are as follows: arsenopyrite, scheelite, magnetite, pyrite, pyrrhotite, sphalerite, galena, chalcopyrite and molybdenite. Average ore grades are 0.33 g/t Au, 46.29 g/t Ag, 0.06% Cu, 4.4% Pb, 2.61% Zn and 29.39% Fe in tunnels, and 0.31 % Cu, 0.52% Pb, 6.29% Zn, 29.29% Fe, 0.03% Mo and 0.12% $WO_3$ in drill cores. Fluid inclusion data shows that Type I (liquid-rich), Type II (vapor-rich) and Type III (halite-bearing) inclusions are coexisted and their homogenization temperatures are quite similar. This indicates that boiling conditions have been reached during the mineralization. It is also likely that the ore solutions were evolved through the mixing between magmatic and meteoric waters. Rhyolite and quartz porphyry far the mineralization probably are not responsible of the Wondong polymetallic mineral deposits.

• Economic and Environmental Geology
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• v.27 no.6
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• pp.537-548
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• 1994

The Weolyu gold-silver deposits at Hwanggan, Chungcheongbukdo, is of a late Cretaceous $(74.24{\pm}1.63Ma)$ epithermal vein-type, and is hosted in the quartz porphyry of late Cretaceous age. Based on mineral paragenetic sequence interpreted from vein structure and mineral assemblages, three stages mineralization were distinguished. A variety of ore minerals occurs including pyrite, sphalerite, chalcopyrite, galena with small amount of electrum, native silver, argentite, pearceite, sb-pearceite, argyrotite. The gangue minerals are quartz, rutile, calcite, apatite, fluorite and rhodochrocite. Wall-rock alteration such as pyritization, chloritization, sericitization, silicification is observed near the quartz veins. Au-Ag minerals were crystallized at middle and late stage of the two mineralization sequences. Results from the analysis of fluid inclusion and thermodynamic calculation indicate that Au-Ag mineral deposits were formed primarily by cooling and dilution of hydrothermal fluids($165{\sim}313^{\circ}C$, 0.4~2.4wt.% equivalent NaCl) with some degree mixing of meteoric water.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.1
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• pp.33-40
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• 1971

Using radioactive $^{40}K$ in potassium, a study was conducted to evaluate the potassium supplying power of different soil types developed on different parent materials. A conversion factor based on two parameters namely $\frac{available\;K_{soil}}{total\;K_{soil}}$ and $\frac{K_{plant}}{K_{soil}}$ was developed and found to be closely related to plant response. According to this characterization soils derived from the various parent materials were ranked as basalt >Silla series>gneiss>porphyry>granite${\gg}$schist. From the point of view of potassium response as measured by yield as similar response pattern was observed. That is, soils derived from basalt to be most responsive as compared to the other soils. The variations among the soils may be accounted for to their potassium bearing mineralogical composition and their stability.

• Economic and Environmental Geology
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• v.12 no.3
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• pp.147-176
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• 1979

The Yeonhwa II zinc-lead mine is characterized by a dozen of moderately dipping tabular orebodies of skarn and zinc-lead sulfides, developed in accordance with the ENE-trending bedding thrusts and bedding planes of the Pungchon Limestone and underlying Myobong Formation, mostly along the contacts of a ENE-trending sill and a NW-trending dike of quartz mononite porphyry. The orebodies occur in three groups: (1) the footwall Wolgok orebodies with respect to the sill, (2) the hangingwall Wolgok orebodies, and (3) the Seongok orebodies extended from dike contacts into carbonate beds. Mineral compositions of these orebodies are dominated by calc-silicates (skarn) associated with ore minerals of sphalerite, galena, and chalcopyrite, as well as sulfide gangue of pyrrhotite. A pair of exo- and endo-skerns in the Wolgok footwall contact aureole between the Pungchon Limestone and quartz monzonite porphyry on the -120 level represents a well-developed symmetrical pattern of mineral zoning: a garnet/quartz zone in the center of exoskarn, two zones of pyroxene with ore minerals on both sides of the garnet/quartz zone, further outwards-an epidote/chlorite-bearing hornfelsic zone in the Myobong slate beyond a zone of unaffected limestone, and an epidote-dominated zone of endo skarn on the opposite side toward fresh quartz monzonite porphyry. These features indicate a combination of two effects on the skarn formation: (1) differences in composition of the host rocks(sedimentary and ignous), and (2) progressive outward migration of inner zones on outer zones on the course of metasomatic replacement of the pre-existing minerals. Microprobe analyses of garnet, pyroxene, pyroxenoids, epidote, and chlorite for nine major elements on a total of 23 mineral grains revealed that: the pyroxenes are hedenbergitic, in most zones, with a gradual decrease of Fe- and Mn-contents toward the central zone, whereas the garnets are andraditic in outer zones, but are grossularitic in the central zone. This indicates a reverse relationship of Fe-contents between pyroxene and garnet across the exoskarn zones. Pyroxenoids are lacking in wollastonite but are dominated by pyroxmangite, rhodonite and bustamite, indicating a Mn-rich nature in bulk chemistry. Pseudomorphic fluorite after garnet occurs abundantly reflecting a fluorine-enhanced evidence of the skarn-forming fluids. Epidote contains 0.19-0.25mole fraction of pistacite, and chlorite is Mn-rich but is Mg-poor. Sulfide mineralization took place with the most Fe-rich pyroxene rather than with garnet as indicated by the fact that the highest value of hedenbergite mole fraction occurs in the ore-bearing pyroxene zone. The Yeonhwa II ores are characterized by high zinc and low lead in metal grade, with minor quantity of copper content in almost constant grade. The hangingwall Wolgok and Seongok orebodies, that formed in a more open environment with respect to their local configurations of geologic setting, are more variable in metal grades and ratios, than are the footwall Wolgok orebodies formed in a more closed condition in a narrow interval of sedimentary beds.