• Economic and Environmental Geology
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• v.31 no.6
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• pp.473-483
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• 1998

The igneous rocks in the Goseong area are composed of the volcanic rocks (andesitic lapilli tuff and rhyodacite), Bulgugsa granites (Hornblende-biotite granite and two pyroxene granite) and intrusive andesites. In the variation diagrams of the trace and rare earth element contents and elemental ratios as well as the REE patterns, the three igneous rock types show different variational trends and patterns. The geochemical features represent that the igneous rocks in the area were formed from three different magmatic pulses. Two independently carried out Rb-Sr isotope experiments for the Goseong granites show that the whole rock ages and Sr initial ratios of the granites are $66.4{\pm}6.2Ma$, $0.70517{\pm}22(2{\sigma})$ and $71.3{\pm}6.8Ma$, $0.70506{\pm}18(2{\sigma})$, respectively. These results suggest that the granites magma originated from the lower crustal materials of igneous origin intruded into the area during the late Cretaceous period. Masan hornblende-biotite granite emplaced at the vicinity of the Goseong area is very similar to the Goseong granite in its mineral compositions, major, trace and rare earth element contents and patterns. The intruding age (100 Ma) of the Masan granite is order than that of the Geseong granite, however. The similarity of the geochemical natures but the contrast of the intruding ages between the Masan and Goseong granites possibly indicate that the magma generation from the same source materials occurred at a temporal interval of ca. 30 Ma.

• Economic and Environmental Geology
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• v.29 no.6
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• pp.689-698
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• 1996

The coal-bearing metapelites from the Hoenam area are interbedded within the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with trace amount of biotite, chlorite, pyrite, rutile and barite. Although the formation was mined for coal, and the contents of V, U and Mo are a higher grade in coal formations than the host metapelites. The ratios of Al/Na and K/Na in coal formation are very heterogeneous and wide range from 10.28 to 90.91 and from 3.73 to 36.60, respectively. The V content increase with increasing Al and Ba contents, but the U and Mo are not related with other elements. Those are suggested that controlled of mineral compositions in coaly metapelites due to substitution, migration and reequilibrium of elements by regional metamorphism. These coal formation were deposited in basin of marine environments and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of Al content versus La, La against Ce, the ratios of La/Ce (0.23 to 0.73) and Th/U (0.03 to 16.6). These rocks also show much variation in $La_N/Yb_N$ (0.53 to 14.19), Th/Yb (0.51 to 6.00) and La/Th (0.15 to 18.92), and their origin is explained by derivation from a mixture of sedimentary and metasedimentary rocks. The wide range in trace and REE element characteristics as Co/Th (0.07 to 3.00), La/Sc (0.04 to 23.48), Sc/Th (0.06 to 7.57), V/Ni (2 to 3319), Cr/V (0.03 to 1.06) and Ni/Co (1.00 to 79.85) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation.

• Journal of Environmental Science International
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• v.14 no.5
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• pp.481-490
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• 2005

Surface sediments and seawater were sampled at Masan and Haengam Bays of Korea, to evaluate contamination by sewage-derived organic matter using fecal sterols, Six stream-water samples into Masan and Haengam Bays were also sampled. Total concentrations of eight sterols (coprostanol, epichloestanol, epicoprostanol, cholesterol, cholestanol, brassicasterol, stigmasterol and $\beta-sitosterol$) were in the range of $1,274\~4,768{\mu}g/g$ dry weight in suspended particulate from the stream-water, $292\~2,244{\mu}g/g$ dry weight in suspended particulate from the seawater and $4.5\~27.2{\mu}g/g$ dry weight in the sediments. Although sterol compositions in sediments, seawater and stream-water were different, cholesterol was the predominant sterol in all samples. The proportion and concentration of coprostanol, a sewage tracer, in stream-water was much higher than those in sediment and seawater. The sterol levels including coprostanol in the sediments and seawater were higher at inner basin than at the outer bay. Some molecular indices and multivariate statistical analysis were used to assess the origin of these sterols and sewage contamination in the study area. The sterol composition patterns in stream-water were mainly associated with contamination by sewage-derived organic matters and those of seawater were associated with the activities of marine-originated organisms. Sterol levels in the sediments were both from the sewage input through stream-water and the marine- originated organisms. This survey suggests that the main source/route of sewage-derived organic matters in Masan Bay is the input of stream-water into the bay.

• Journal of the Korean earth science society
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• v.30 no.1
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• pp.33-39
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• 2009

This paper presents the occurrence and characteristics of the basaltic andesite-siltstone peperite in the lower part of the Gyehwari Formation (Cretaceous), Buan-gun, Jeonbuk province, SW Korea. The peperite is associated with tabular basaltic andesite body, concordantly intercalated with red siltstone and silty sandstone interbeds of floodplain facies. Development of the peperite along the upper margin of the andesite and its textural transition from a dispersed blocky type inward into a closely packed type collectively indicate an intrusive origin (?sill) of the andesite. Magma intrusion and subsequent peperite formation suggest an active syndepositional volcanism since the early stage of evolution of the Gyehwa Basin. The andesite is dated at Late Cretaceous (Santonian) by K-Ar whole-rock radiometric method.

• 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.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.53-57
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• 2009

The Oriental flower arrangements have the beauty of a strict triangle in a symmetrical three-dimensional effect as the form of flower tribute to gods in ancient times and used frogs to fix flowers to a basin easily. Flower arrangements of a conical shape made by repeatedly piled flowers in ancient Egypt shows the origin of the present vertical form of the Western flower arrangements. Flower arrangements in ancient Greece formed in a smooth S shape, while Roman flower arrangements were rich and gorgeous in a lowering and thin shape horizontally. Persians were showing triangular forms similar to the Oriental three-dimensional effect. The basic form of flower arrangements in the age of Renaissance was also created upon the ancient one, descending to Art Nouveau when flower arrangements were widely expressed from mass to space aesthetics led by America in the 20th century influenced by mild color, simplicity and realistic description of the Oriental art in the late 19th century. The Western flower arrangements are focused on formation, same as the Oriental ones, yet they disregard naturality and based on practicality.

• Economic and Environmental Geology
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• v.18 no.4
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• pp.331-342
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• 1985

The Dongbo tungsten-molybdenum deposits are fissure-filling veins emplaced in granites of late Cretaceous age. Integrated field, mineralogic and fluid inclusion studies were undertaken to illuminate the characters and origin of the ore deposits. Mineral paragenesis is complicated by repeated fracturing, but four distinct depositional stages can be recognized; (I) tungsten-molybdenum minerals-quartz-chlorite stage, (II) iron-oxide and sulfides-quartz stage, (III) iron -oxide-base metal sulfides-sulfosalts-quartz-carbonates stage, (IV) barren rhodochrosite-zeolite stage. Fluid inclusion studies were carried out for stage I quartz and stage III quartz, sphalerite and calcite. Fluid inclusion studies reveals highly systematic trends of homogenization temperature and salinity throughout the mineralization. Ore fluids during stage I were complex, NaCl rich brine and salinity reached values as high as 34.4 weight percent equivalent NaCl, but the later ore fluids were more dilute and reached to 9.7 weight percent equivalent NaCl during stage III. Intermittent boiling of ore fluid during stage I is indicated by the fluid inclusions in stage I quartz. Depositional temperatures and pressures during stage I range from $520^{\circ}C$ to $265^{\circ}C$and from 600 to 400 bars. Homogenization temperatures of the stage III quartz, sphalerite and calcite range from $305^{\circ}C$ to $190^{\circ}C$. Fluid inclusion data from the Dongbo mine are nearly similar to those from other hydrothermal tungsten deposits in the Kyeongsang basin. Depositional temperature and salinity of ore fluids during precipitation of tungsten-molybdenum minerals in Dongbo mine were much higher, but $CO_2$ contents were much lower than those from hydrothermal tungsten-molybdenum deposits of late Cretaceous plutonic association in central parts of Korean peninsula.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.313-331
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• 2022

Natural or native abiotic molecular hydrogen (H₂) is a major component in natural gas, however yet its importance in the global energy sector's usage as clean and renewable energy is underestimated. Here we review the occurrence and geological settings of native hydrogen to demonstrate the much widesprease H₂ occurrence in nature by comparison with previous estimations. Three main types of source rocks have been identified: (1) ultramafic rocks; (2) cratons comprising iron (Fe²⁺)-rich rocks; and (3) uranium-rich rocks. The rocks are closely associated with Precambrian crystalline basement and serpentinized ultramafic rocks from ophiolite and peridotite either at mid-ocean ridges or within continental margin(Zgonnik, 2020). Inorganic geological processes producing H₂ in the source rocks include (a) the reduction of water during the oxidation of Fe²⁺ in minerals (e.g., olivine), (b) water splitting due to radioactive decay, (c) degassing of magma at low pressure, and (d) the reaction of water with surface radicals during mechanical breaking (e.g., fault) of silicate rocks. Native hydrogen are found as a free gas (51%), fluid inclusions in various rock types (29%), and dissolved gas in underground water (20%) (Zgonnik, 2020). Although research on H₂ has not yet been carried out in Korea, the potential H₂ reservoirs in the Gyeongsang Basin are highly probable based on geological and geochemical characteristics including occurrence of ultramafic rocks, inter-bedded basaltic layers and iron-copper deposits within thick sedimentary basin and igneous activities at an active continental margin during the Permian-Paleogene. The native hydrogen is expected to be clean and renewable energy source in the near future. Therefore it is clear that the origin and exploration of the native hydrogen, not yet been revealed by an integrated studies of rock-fluid interaction studies, are a field of special interest, regardless of the presence of economic native hydrogen reservoirs in Korea.

• Economic and Environmental Geology
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• v.52 no.1
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• pp.107-118
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• 2019

Two assertions about the process the formation of the high-purity limestone in the Taebaeksan Basin, categorized into syngenetic and epigenetic origin, are verified on the basis of its oxygen-carbon stable isotopic characteristics. The carbonate rocks sampled from the selective six high-purity limestone mines and several outcrops in the Daegi formation are featured by various colors such as the gray, light gray and dark gray. They show a wide range of oxygen stable isotope ratios (4.5 ~ 21.6 ‰), but a narrow range of carbon stable isotope ratios (-1.1 ~ 0.8 ‰, except for vein calcite), which means that they had not experienced strong hydrothermal alteration. In addition, there is no difference in the range of the oxygen stable isotope ratios by mine and color, and it is similar to the range from surrounding outcrop samples. These results indicate that the effect of the hydrothermal alteration were negligible in the generation of high-purity limestone in deposit scale. Whereas, the carbonate rocks can be divided texturally into two groups on the basis of an oxygen isotope ratio; the massive-textured or well-layered samples (>15 ‰), and the layer-disturbed (or layer-destructed) and showing over two colors in one sample (<15 ‰). In the multi-colored samples, the bright parts are characterized by the very low oxygen stable isotope ratios, compared to the dark parts, implying the increase in brightness of the carbonate rocks could be induced by the interaction between hydrothermal fluid and rock. However, these can be applied in a small scale such as one sample and are not suitable for interpretation of the generation of high-purity limestone as a deposit scale. In particular, the high oxygen isotope ratios from the recrystallized white limestone suggest that hydrothermal fluids are also rarely involved during recrystallization process. In addition, the occurrences of the high-purity limestone orebody strongly support the high-purity limestone in the area are syngenetic rather than epigenetic; the high-purity limestone layers in the area show continuous and almost horizontal shapes, and is intercalated between dolomite layers. Consequently, the overall reinterpretation based on the sequential stratigraphy over the Taebaeksan basin would play an important role to find additional reserves of the high-purity limestone.

• The Journal of the Petrological Society of Korea
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• v.16 no.3
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• pp.116-128
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• 2007

Detailed geological mapping, petrographic study, analyses of geochemistry and magnetic susceptibility, and K-Ar dating were carried out in order to determine the origin, age, and stratigraphic implications of granitic rock fragments in the pyroclastic rocks, SE Jinhae city, southern part of the Gyeongsang Basin. As a result, it was found that the area is composed of volcanics and tuffaceous sediments of the Yucheon Group, Bulguksa granites, pyroclastics bearing granitic rock fragments, $basalt{\sim}basaltic$ andesite, and rhyolite in ascending stratigraphic order. The granitic rock fragments in the pyroclastic rocks are divided into granodiorite and biotite granite, which have approximately the same characteristics as the granodiorite and the biotite granite of the Bulguksa granites, respectively, in and around the study area including color, grain size, mineral composition, texture (perthitic and micrographic textures), intensity of magnetic susceptibility (magnetite series), and geochemical features (calc-alkaline series and REE pattern). This leads to the conclusion that the rock fragments originated from the late Cretaceous Bulguksa granites abundantly distributed in and around the study area, but not from the basement rocks of the Yeongnam massif or the Jurassic granites. Based on relative and absolute ages of various rocks in the study area, the pyroclastics bearing granitic rock fragments are interpreted to have erupted between 52 and 16 Ma, i.e. during the Eocene and early Miocene. These results indicate that the various volcanisms, acidic to basic in composition, occurred after the intrusion of the Bulguksa granites, contrary to the general stratigraphy of the Gyeongsang Basin. Very detailed and cautious mapping together with relative and absolute age determinations are, thus, necessary in order to establish reliable stratigraphy of the Yucheon Group in other areas of the Gyeongsang Basin.