• Journal of Korean Society of Forest Science
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• v.54 no.1
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• pp.49-59
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• 1981

In order to elucidate the process of plant succession of the Japanese red pine forests caused by pine gall midge, Thecodoplosis japonensis, in the area of Chungbuk and Kyongbuk, 12 study plots, 4 plots from each three districts, were set up. Districts A (Cheongwon)not attacked by this insect, as the check, District B(Gumi) in which the insect outbreak occured 5 years ago, and District C(Yeongdong)in which the insect outbreak occured 10 years ago, were sampled. The surveyed were some environmental factors, the number of woody plants, relative density, relative dominance values, species composition of plots by layer(upper, middle and ground), importance values, species diversity, similarity and dissimilarity index, etc. The results obtained are summarized as follows: The accumulation of litter on the ground was increased with the lengthening the insect damage duration. Through the crown opening and litter accumulation, the light intensity, temperature condition and soil moisture and nutrient content might be altered. According to the changes of species composition were forced. In general, the Genus Quercus, as a compensation species, has sprung up. The relative importance values for Q.aliena, Q.serrata, and Q.variabilis were significantly increased in the insect infested forests. 2. the stand structure and species composition of the insect attacked forest about 5 years later after the outbreak become complex and diverse. However, since this time, the simplicity of these regards become restored up to 10 years after the outbreak. 3. As the synthetic analysis of plant succession process, the relative values calculated from the relative density and the relative dominance values shown the dominant status of Genus Quercus in the heavily damaged forests. In addition, Genus Rhododendron and Genus Lespedeza with higher frequency become the ground vegetation components. They were gradually increased along the time elapsing after the insect out-break. 4. The differences in connection with the soil moisture contents, the organic matter contents which might give some influences to the vegetation change were hardly recognizable statistically among the studied plots by three district groups. We estimated that the annual mean precipitation and the annual mean temperature did not operated any meaningful effects on the vegetation alteration among plots between districts.

• Economic and Environmental Geology
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• v.43 no.5
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• pp.467-475
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• 2010

The Landsat and ASTER data have been used in mineralogical and lithological studies, and they have also proved to be useful tool in the initial steps for mineral exploration throughout Nevada mining district, US. Huge pyrophyllite quarry mines, including Jungang, Samsung, Kyeongju, and Naenam located in the southeastern part of Gyeongsang Basin. The geology of study area consists mainly of Cretaceous volcanic rocks, which belong into Cretaceous Hayang and Jindong Group. They were intruded by Bulgugsa granites, so called Sannae-Eonyang granites. To extraction of Ratio model for pyrophyllite deposits, tuffaceous rock and pyrophyllite ores from the Jungang mine used in reflectance spectral analysis and these results were re-sampled to Landsat and ASTER bandpass. As a result of these processes, the pyrophyllite ores spectral features show strong reflectance at band 5, whereas strong absorption at band 7 in Landsat data. In the ASTER data, the pyrophyllite ores spectral features show strong absorption at band 5 and 8, whereas strong reflectance at band 4 and 7. Based on these spectral features, as a result of application of $Py_{Landsat}$ model to hydrothermal alteration zone and other exposed sites, the DN values of two different areas are 1.94 and 1.19 to 1.49, respectively. The differences values between pyrophyllite deposits and concrete-barren area are 0.472 and 0.399 for $Py_{ASTER}$ model, 0.452 and 0.371 for OHIb model, 0.365 and 0.311 for PAK model, respectively. Thus, $Py_{ASTER}$ and $Py_{Landsat}$ model proposed from this study proved to be more useful tool for the extraction of pyrophyllite deposits relative to previous models.

• Economic and Environmental Geology
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• v.45 no.6
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• pp.599-622
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• 2012

The phase I soil geochemical exploration was carried out targeting around Chau Binh area far from about 14 km with southeastern direction from Quy Chau within Nghe An province. The interval of sampling are horizontal 300 m with 14 line and longitudinal 500 m with 15 line, resulting in 194 soil samples. Based on the result of the phase I soil geochemical exploration, the phase II detailed pitting survey was carried out targeting the grid point with high TREO content, resulting in 56 soil samples within 7 pits. The geology of survey area are consisted of Ban Chieng biotite granite complex and Dai Loc gneissic granite complex intruding Bu Khang formation comprising of schist, gneiss and limestone. Main mineralization in the study area have the characteristics of occurrence with tin, ruby and REE-bearing monazite(about 300 g/t) and xenotime(about 10 g/t) to be thought as occurring at the alteration zone of granite complex. In order to elucidate the source rock of monazite and xenotime confirmed from heavy sand, soil geochemical exploration was carried out. As a analysis result with ICP-MS on the soil samples from the phase I soil geochemical exploration, total REE oxide content of background amount to about 2 times of crustal abundance, enriching the heavy rare earth(about 2 times) and light rare earth(about 1.84 times). As a analysis result with ICP-MS on the soil samples from the phase II soil detailed pit survey, we identified outcrop considering as economic ore body at the grid point 4-7 pit with N40W attitude. As a synthetic consideration on the phase I soil geochemical exploration and phase II detailed pit survey, we tentatively designated areas considering as the extension of economic ore body with REE anomaly. In the near future, we have the plan to carry out the geophysical exploration and test drilling targeting the interval anticipated to the economic ore body.

• Journal of Conservation Science
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• v.23
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• pp.25-37
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• 2008

This study focuses on identification of mineralogical and geochemical characteristics and interpretation of raw material sources for prehistoric chlorite beads excavated from Geoseokri site in Boseong and Buntori site in Haenam, Korea. These prehistoric beads consist of three grayish blue ring-shaped beads, one dark green tubular bead and one greenish black tubular bead that show acicular-columnar and fibrous microtexture. The beads are composed of $SiO_2$, $Al_2O_3$, MgO and FeO as majors and a trace amount of $K_2O$, CaO and Na_2O$. Mineral species is mostly chlorite with a small amount of quartz and feldspar. Quantitative analysis indicates that the grayish blue ring-shaped beads and the dark green tubular bead belong to clinochlore and the greenish black tubular bead does to the boundary between clinochlore and sheridantie. Chlorite is a hydrous phyllosilicate mineral and it shows various microtexture of acicular, sheeted, earthy, granular andfibrous shapes. As its hardness is 2, chlorite is easily engraved due to its softness. It has aesthetic worthy as it shows green, black and greenish gray colors and pearly to greasy luster as well. These factors would lead to the extensive use of chloritic beads as ornaments from prehistoric times. Though the mineral sources of the chlorite beads can be found in central western region of Chungnam and Iwon of Hamnam, those areas are too distant from the two relic sites. Instead, chlorite ores commonly occur as altered products in wall rock alteration zone of every hydrothermal deposit. Therefore, it is probable that raw materials of chlorite were supplied from neighboring hydrothermal environment rather than far deposits. The result needs further study to verify raw material provenance interpretation, supply, manufacture and distribution on the basis of archaeological points of view.

• The Journal of the Petrological Society of Korea
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• v.21 no.3
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• pp.335-365
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• 2012

Fission-track (FT) thermochronological records from SE Korean Cretaceous-Paleogene granitic plutons in different fault-bounded blocks reveal contrasting cooling and later thermal histories. Overall cooling patterns are represented by a monotonous (J-shaped) curve in most plutons except some Cretaceous granites retaining a complicated (N-shaped) path due to post-reset re-cooling. Discriminative cooling rates over different temperature ranges can be explained for individual plutons with respect to relative pluton sizes, differences in initial heat loss depending on country rocks, and the presence and proximity of later igneous activity. Even within a single batholith, cooling times for different isotherms were roughly contemporaneous with respect to positions. Insignificant deviations in cooling ages from two different plutons in succession across the Yangsan fault may suggest their contemporaneity before major horizontal fault movement. The extent of later thermal rise recorded locally along the Yangsan and Dongnae fault zones were reached the Apatite Partial Stability Zone ($70-125^{\circ}C$), but did not exceed $200^{\circ}C$. Thermal alteration from fractured zones in the Yangsan-Ulsan fault junction may suggest a thermal reset above $290^{\circ}C$ resulting a complete reset in FT sphene age (31 Ma), caused by a tectonic subsidence in Early Oligocene. A consistency in FT zircon/apatite ages (24 Ma) may imply a sudden rapid cooling over $200-105^{\circ}C$, plausibly related to the abrupt tectonic uplift of the Pohang-Gampo Block including the fault junction in Late Oligocene. A remarkable trend of lower cooling ages for $300-200-100^{\circ}C$ isotherms (i.e., 19% for FT sphene and K-Ar biotite; 20% for FT zircon; 27% for FT apatite) from the east of the Ulsan fault (Pohang-Gampo Block) comparing to the west of the fault may be attributed to retarded cooling times from the Paleogene granites and also reflected by their partially-reduced apatite ages due to later thermal effects.

• Economic and Environmental Geology
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• v.39 no.1 s.176
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• pp.9-25
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• 2006

Baekun gold-silver deposit is an epithermal quartz vein that is filling the fault zone within Triassic or Jurassic foliated granodiorite. Mineralization is associated with fault-breccia zones and can be divided into two stages. Stage I which can be subdivided early and late depositional stages is main ore mineralization and stage II is barren. Early stage I is associated with wallrock alteration and the formation of sulfides such as arsenopyrite, pyrite, pyrrhotite, sphalerite, marcasite, chalcopyrite, stannite, galena. Late stage I is characterized by Au-Ag mineralization such as electrum, Ag-bearing tetrahedrite, stephanite, boulangerite, pyrargrite, argentite, schirmerite, native silver, Ag-Te-Sn-S system, Ag-Cu-S system, pyrite, chalcopyrite and galena. Fluid inclusion data indicate that homogenization temperatures and salinity of stage I range from $171.6^{\circ}C\;to\;360.8^{\circ}C\;and\;from\;0.5\;to\;10.2\;wt.\%\;eq.$ NaCl, respectively. It suggest that ore forming fluids were cooled and diluted with the mixing of meteoric water. Also, Temperature (early stage I: $236\~>380^{\circ}C,\;$ late stage $I: <197\~272^{\circ}C$) and sulfur fugacity (early stage $I:\;10^{-7.8}$ a atm., late stage I: $10^{-14.2}\~10^{-l6}atm$.) deduced mineral assemblages from stage 1 decrease with paragenetic sequence. Sulfur ($2.4\~6.1\%_{\circ}$(early stage $I=3.4\~5.3\%_{\circ},\;late\;stage\;I=2.4\~6.1\%_{\circ}$)), oxygen ($4.5\~8.8\%_{\circ}$(quartz: early stage $I=6.3\~8.8\%_{\circ}$, late stage $I=4.5\~5.6\%_{\circ}$)), hydrogen ($-96\~-70\%_{\circ}$ (quartz: early stage $I=-96\~-70\%_{\circ},\;late\;stage\;f=-78\~-74\%_{\circ},\;calcite:\;late\;stage\;I=-87\~-76\%_{\circ}$)) and carbon ($-6.8\~-4.6\%_{\circ}$ (calcite: late stage I)) isotope compositions indicated that hydrothermal fluids may be magmaticorigin with some degree of mixing of another meteoric water for paragenetic time.

• Economic and Environmental Geology
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• v.47 no.2
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• pp.147-168
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• 2014

The soil geochemical exploration was carried out targeting around Tri Le area far from about 30 km with northwestern direction from Que Phong within Nghe An province. The interval of sampling are horizontal 200 m interval with 23 line and longitudinal 300 m with 10 line, resulting in 228 soil samples. Based on the result of the soil geochemical exploration, the detailed pitting survey was carried out targeting the grid point with high TREO content, resulting in 75 soil samples within 7 pits. The geology of survey area are consisted of Ban Chieng biotite granite complex and granitic gneiss intruding Ban Khang formation comprising of quartz schist and marble. Main mineralization in the study area have the characteristics of occurrence with tin, ruby and REE-bearing monazite and xenotime to be thought as occurring at the alteration zone of granite complex. In order to elucidate the source rock of monazite and xenotime confirmed from heavy sand, soil geochemical exploration was carried out. As a analysis result with ICP-MS on the soil samples from the soil geochemical exploration, total REE oxide content of background amount to about 2 times of crustal abundance, enriching the heavy rare earth(about 2 times) and light rare earth(about 1.5 times). As a analysis result with ICP-MS on the soil samples from the soil detailed pit survey, we only identified outcrop considering as economic weathered granite body at the grid point 1-10 pit among 7 pits. As a synthetic consideration on the soil geochemical exploration and detailed pit survey, we tentatively designated Tri Le area as no promising target for REE. In 2014, we have the plan to carry out the soil geochemical exploration targeting the extended economic REE ore body in Quy Chau as project area from 2011 to 2012.

• Korean Journal of Heritage: History & Science
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• v.37
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• pp.285-307
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• 2004

Synthesize and examine petrological characteristic and geochemical characteristic by weathering formation of rock and progress of weathering laying stress on stone cultural properties of Unjusa temple of Chonnam Hwasun county site in this research. Examine closely weathering element that influence mechanical, chemical, mineralogical and physical weathering of rocks that accomplish stone cultural properties and these do quantification, wish to utilize by a basic knowledge for conservation scientific research of stone cultural properties by these result. Enforced component analysis of rock and mineralogical survey about 18 samples (pyroclastic tuff; 7, ash tuff; 4, granite ; 4, granitic gneiss; 3) all to search petrological characteristic and geochemical characteristic by weathering of Unjusa temple precinct stone cultural properties and recorded deterioration degree about each stone cultural properties observing naked eye. Major rock that constitution Unjusa temple one great geological features has strike of N30-40W and dip of 10-20NE being pyroclastic tuff. This pyroclastic tuff is ranging very extensively laying center on Unjusa temple and stone cultural properties of precinct is modeled by this pyroclastic tuff. Stone cultural propertieses of present Unjusa temple precinct are accomplishing structural imbalance with serious crack, and because weathering of rock with serious biological pollution is gone fairly, rubble break away and weathering and deterioration phenomenon such as fall off of a particle of mineral are appearing extremely. Also, a piece of iron and cement mortar of stone cultural properties everywhere are forming precipitate of reddish brown and light gray being oxidized. About these stone cultural properties, most stone cultural propertieses show SD(severe damage) to MD(moderate damage) as result that record Deterioration degree. X-ray diffraction analysis result samples of each rock are consisted of mineral of quartz, orthoclase,plagioclase, calcite, magnetite etc. Quartz and feldspar alterated extremely in a microscopic analysis, and biotite that show crystalline form of anhedral shows state that become chloritization that is secondary weathering mineral being weathered. Also, see that show iron precipitate of reddish brown to crack zone of tuff everywhere preview rock that weathering is gone deep. Tuffs that accomplish stone cultural properties of study area is illustrated to field of Subalkaline and Peraluminous, $SiO_2$(wt.%) extent of samples pyroclastic tuff 70.08-73.69, ash tuff extent of 70.26-78.42 show. In calculate Chemical Index of Alteration(CIA) and Weathering Potential Index(WPI) about major elements extent of CIA pyroclastic tuff 55.05-60.75, ash tuff 52.10-58.70, granite 49.49-51.06 granitic gneiss shows value of 53.25-67.14 and these have high value gneiss and tuffs. WPI previews that is see as thing which is illustrated being approximated in 0 lines and 0 lines low samples of tuffs and gneiss is receiving esaily weathering process as appear in CIA. As clay mineral of smectite, zeolite that is secondary weathering produce of rock as result that pick powdering of rock and clothing material of stone cultural properties observed by scanning electron micrographs (SEM). And roots of lichen and spore of hyphae that is weathering element are observed together. This rock deep organism being coating to add mechanical weathering process of stone cultural properties do, and is assumed that change the clay mineral is gone fairly in stone cultural properties with these. As the weathering of rocks is under a serious condition, the damage by the natural environment such as rain, wind, trees and the ground is accelerated. As a counter-measure, the first necessary thing is to build the ground environment about protecting water invasion by making the drainage and checking the surrounding environment. The second thing are building hardening and extirpation process that strengthens the rock, dealing biologically by reducing lichens, and sticking crevice part restoration using synthetic resin. Moreover, it is assumed to be desirable to build the protection facility that can block wind, sunlight, and rain which are the cause of the weathering, and that goes well with the surrounding environment.