• Economic and Environmental Geology
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• v.31 no.3
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• pp.249-264
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• 1998

The Creataceous volcanic rocks distributed in the southeastern part (Kyeongsang basin) of Korea peninsula are composed of basalt, basaltic andesite, andesite, dacite and rhyolite. The variation of major elements show that contents of MgO, CaO, $FeO^T$, $Al_2O_3$, $TiO_2$ and $P_2O_5$ decrease with increasing of $SiO_2$, but $K_2O$ contents are increased slightly, $Na_2O$ widely dispersed. We can show slightly inflection point and low frequency of dacites in range between 63-65 wt.% $SiO_2$, while continuous trend exit in variation diagram. Variation trends in Harker diagrams for the major, minor, trace and REEs suggest that the BAV (basaltic to andesitic volcanics) and DRV (dacitic to rhyolitic volcanics) are not related to a simple crystal fractionation process. In the regime of under 65 wt. % in silica content, fractionation of olivine and clinopyroxene is predominant, while that of plagioclase happens strongly higher than 65 wt.% (e.g., $SiO_2$, vs. Eu and Sr, MgO vs. $Al_2O_3$ and CaO). The latter means low-pressure fractional crystallization for DRV. On the discriminant diagram, DRV are located in more mature environment than BAV. The $(Ce/Sm)_N$ vs. CeN digram shows that these two classes cannot be related to crystal fractionation. If they had been produced by fractionation, although they plotted in a slightly elongate cluster along the same horizontal trend, DRV should lie to the right of these primitive compositions. These diagrams clearly rule out a simple fractionation throughout from BAV to DRV. BAV had been influenced greatly subductiong slab as shown by K/Yb vs. Ta/Yb. We suggest that BAV primitive magma generated higher degree of partial melting than DRV primitive magma. LILE (K, Ba, $Rb{\pm}Th$) enriched characteristics as shown in BAV are inherited from subducting slab fluids and/or higher degree of partial melting of mantle material. However, lower degree of partial melting of mantle relative to BA V and contamination at high-level magma reservoir caused LILE enrichment to DRV.

• Economic and Environmental Geology
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• v.39 no.6 s.181
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• pp.675-687
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• 2006

The purpose of this study is to determine the geochemical characteristics of the stream sediments in the Cheongpung area. So that we can understand the natural background and predict the prospects of geochemical disaster, if any. We collected the stream sediments samples by wet sieving along the primary channels and slow dried the collected samples in the laboratory and ground them to pass a 200 mesh using an alumina mortar and pestle for chemical analysis. Miner-alogical characteristics, major, trace and rare earth elements were determined by XRD, XRF, ICP-AES and NAA analysis methods. For geochemical characteristics on the geological group of stream sediments, the studied area was grouped into granitic gneiss area, metatectic gneiss area, Dado tuff area, Yuchi conglomerate area, and Neungju flow area in the Cheongpung area. Contents of major elements for the stream sediments in the Cheongpung area were $SiO_2\;47.31{\sim}72.81\;wt.%,\;A1_2O_3 \;11.26{\sim}21.88\;wt.%,\;Fe_2O_3\;2.83{\sim}8.39\;wt.%,\;CaO\;0.34{\sim}7.54\;wt.%,\;MgO\; 0.55{\sim}3.59\;wt.%,\;K_2O\;1.71{\sim}4.31\;wt.%,\;Na_2O\;0.56{\sim}2.28\;wt.%,\;TiO_2\;0.46{\sim}1.24\;wt.%,\;MnO\;0.04{\sim}0.27\;wt.%,\;P_2O_5\;0.02{\sim}0.45\;wt.%$. The con-tents of trace and rare earth elements for the stream sediments were $Ba\;700ppm{\sim}8990ppm,\;Be\;1.0{\sim}3.50ppm,\;Cu\;6.20{\sim}60ppm,\;Nb\;12{\sim}28ppm,\;Ni\;4.4{\sim}61ppm,\;Pb\;13{\sim}34ppm,\;Sr\;65{\sim}787ppm,\;V\;4{\sim}98ppm,\;Zr\;32{\sim}164ppm,\;Li\;21{\sim}827ppm,\;Co\;3.68{\sim}65ppm,\;Cr\;16.7{\sim}409ppm,\;Cs\;2.72{\sim}37.1ppm,\;Hf\;4.99{\sim}49.2ppm,\;Rb\;71.9{\sim}649ppm,\;Sb\;0.16{\sim}5.03ppm,\;Sc\;4.97{\sim}52ppm,\;Zn\;26.3{\sim}375ppm,\;Ce\;60.6{\sim}373ppm,\;Eu\;0.82{\sim}6ppm,\;Yb\;0.71{\sim}10ppm$.

• Journal of the Mineralogical Society of Korea
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• v.14 no.1
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• pp.39-51
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• 2001

공주군 유구면 일대의 화강암질 편마암의 풍화작용에 따른 원소의 거동과 pH와 이차광물과의 관계를 XRF, ICP-AES, ICP-MS를 이용한 원소분석결과를 통하여 검토하였다. 이 지역의 암석은 pH6 내외의 산성환경, 침철석, 아나타제와 같은 다양한 이차광물을 생성하면서 심각한 화학조성의 변화를 초래했다. 주원소의 화학조성을 이용한 풍화지수는 토양층에서 79~88로 모암 중의 사장석이 용해되고 흑운모가 변질되어 캐올리광물의 생성이 활발한 방향으로 풍화작용이 진행되었다. 지표층으로 가면서 Al에 대한 주 원소의 거동은 Si, Ca, Na, K, P가 감소하고 Fe, Ti, Mn이 증가하는 경향을 보이며 pH가 낮은 풍화단면에서 주 원소의 변화량이 더 크다. 이 풍화대에서 Mg은 거의 일정하다. Li, As 모든 전이원소는 pH가 감소함에 따라 증가하며 특히 이들 원소는 Fe의 함량과 비례해서 증가해 침철석과 공침하였거나 표면에 흡착되어 있는 것으로 보인다. Ga은 Fe와 비례하기는 하지만 변화량은 전 풍화단면에서 일정하다. Zr, Mo, Sn, Cd은 pH에 변화에 상관없이 일정한 반면에 Rb, Sr, Ba, Y, Pb, Th, U 등은 감소하는 경향을 보인다. 특히 Rb 과 Sr은 Ca에 비례해서 감소한다. 희토류원소는 전 풍화단면에서 감소하는 경향을 보이는데 $Al_2$$O_3$에 대한 상대적인 변화량을 보면 경희토류원소는 사프롤라이트(saprolite)하부와 상부에서 부화되어 있고 중부 사프롤라이트와 토양층에서 감소하는 반면에 중희토류원소는 사프롤라이트 하부와 상부에서 감소하고 중부사프롤라이트 및 토양층에서 부화되는 경향을 보인다. 전반적으로 희토류원소의 원자번호가 클수록 손실율이 커진다. 이 풍화단면에서 원소의 거동은 각 풍화층의 pH와 생성된 이차광물의 조성에 지배를 받았다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.167-167
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• 2008

The barium strontium calcium titanate powders were prepared by sol-gel method. Ferroelectric $(Ba_{0.54}Sr_{0.36}Ca_{0.1})TiO_3$(BSCT) thick films were fabricated by the screen-printing method on alumina substrate. And we investigated the structural and dielectric properties of BSCT thick films with the variation of sintering temperature. As a result of thermal analysis, BSCT polycrystalline perovskite phase was formed at around $660^{\circ}C$. The results of X-ray diffraction analysis were showed a cubic perovskite structure without presence of the second phase in all BSCT thick films. The average grain size and the thickness of the specimen sintered at $1450^{\circ}C$ were about 1.6 mm and 45 mm, respectively. The relative dielectric constant increased and the dielectric loss decreased with increasing the sintering temperature, the values of the BSCT thick films sintered at $1450^{\circ}C$ were 5641 and 0.4% at 1kHz, respectively.

• Economic and Environmental Geology
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• v.23 no.2
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• pp.245-259
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• 1990

Petrochemical analyses of granitic rocks including trace element, REE and oxygen isotope were carried out to understand petrogenesis of plutonic rocks from the Chungju, Wolaksan and Jecheon granite batholiths, which might be related with tungsten-base metal-fluorite mineralization in the Hwanggangri metallogenic province. Different geochemical characteristics such as major and trace elements were found between Jurassic Daebo granitic rocks (Chungju, Jecheon, Wonju, and Boeun granitic rocks) and Cretaceous Bulgugsa granitic rocks (Wolaksan, Muamsa and Sokrisan granitic rocks). Cretaceous granitoids are characterized by high $SiO_2$and $K_2O$ contents and low $TiO_2$, $Al_2O_3$, MgO and CaO contents. They also have relatively high contents of trace elements(Zn, V, Co, Cr, Sr, and Ba) in comparison with the Jurassic granitoids. (Eu)/($Eu^*$) and $(La/Lu)_{CN}$ ratios of Jurassic plutons vary from 0.78 to 1.13 and from 26.02 to 30.5, respectively, while the ratios of Cretaceous ones range from 0.22 to 0.28 and from 4.42 to 14.2, respectively. The REE patterns of the Cretaceous and Jurassic granitic rocks have quite different Eu anomalies: large negative Eu anomaly in the former, and mild or absent Eu anomaly in the latter. The large Eu negative of Cretaceous granitic rocks are interpreted as a differentiated product of fractional crystallization of granitic magma deduced by Rayleigh fractionation model(Tsusue et al., 1987). Oxygen isotopic compositions of quartz for Daebo and Bulgugsa granitic rocks range from 9.98 to 10.51‰ and from 8.26 to 9.56‰, respectively. The Daebo granitic rocks enriched in $^{18}0$ suggest that the magma be undergone different partial melting processes from the Bulgugsa ones. Of the Bulgugsa granitoids, Wolaksan and Sokrisan mass have different contents of trace elements and ${\delta}\;^{18}0$ values of the silicate minerals, which indicate that they are not from the identical source of magma. Many mineral deposits are distributed in and/or near the Wolaksan and Muamsa granitic rocks, but a few mineral deposits are found in and near the Chungju and Jecheon granite batholiths. It might be depend on geochemisty of the related igneous rocks which have low contents of Ba, Sr, Co, V, Cr, Ni, Zn and high contents of Nb and Y, and on lithology of country rocks such as cabonate and noncarbonate rocks.

• Economic and Environmental Geology
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• v.46 no.2
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• pp.179-198
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• 2013

The Boziguoer A-type granitoids in Baicheng County, Xinjiang, belong to the northern margin of the Tarim platform as well as the neighboring EW-oriented alkaline intrusive rocks. The rocks comprise an aegirine or arfvedsonite quartz alkali feldspar syenite, an aegirine or arfvedsonite alkali feldspar granite, and a biotite alkali feldspar syenite. The major rock-forming minerals are albite, K-feldspar, quartz, arfvedsonite, aegirine, and siderophyllite. The accessory minerals are mainly zircon, pyrochlore, thorite, fluorite, monazite, bastnaesite, xenotime, and astrophyllite. The chemical composition of the alkaline granitoids show that $SiO_2$ varies from 64.55% to 72.29% with a mean value of 67.32%, $Na_2O+K_2O$ is high (9.85~11.87%) with a mean of 11.14%, $K_2O$ is 2.39%~5.47% (mean = 4.73%), the $K_2O/Na_2O$ ratios are 0.31~0.96, $Al_2O_3$ ranges from 12.58% to 15.44%, and total $FeO^T$ is between 2.35% and 5.65%. CaO, MgO, MnO, and $TiO_2$ are low. The REE content is high and the total ${\sum}REE$ is $(263{\sim}1219){\times}10^{-6}$ (mean = $776{\times}10^{-6}$), showing LREE enrichment HREE depletion with strong negative Eu anomalies. In addition, the chondrite-normalized REE patterns of the alkaline granitoids belong to the "seagull" pattern of the right-type. The Zr content is $(113{\sim}1246){\times}10^{-6}$ (mean = $594{\times}10^{-6}$), Zr+Nb+Ce+Y is between $(478{\sim}2203){\times}10^{-6}$ with a mean of $1362{\times}10^{-6}$. Furthermore, the alkaline granitoids have high HFSE (Ga, Nb, Ta, Zr, and Hf) content and low LILE (Ba, K, and Sr) content. The Nb/Ta ratio varies from 7.23 to 32.59 (mean = 16.59) and the Zr/Hf ratio is 16.69~58.04 (mean = 36.80). The zircons are depleted in LREE and enriched in HREE. The chondrite-normalized REE patterns of the zircons are of the "seagull" pattern of the left-inclined type with strong negative Eu anomaly and without a Ce anomaly. The Boziguoer A-type granitoids share similar features with A1-type granites. The average temperature of the granitic magma was estimated at $832{\sim}839^{\circ}C$. The Boziguoer A-type granitoids show crust-mantle mixing and may have formed in an anorogenic intraplate tectonic setting under high-temperature, anhydrous, and low oxygen fugacity conditions.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.469-484
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• 2022

The Janggun Pb-Zn deposit has been known one of the four largest deposits (Yeonhwa, Shinyemi, Uljin) in South Korea. The geology of this deposit consists of Precambrian Weonnam formation, Yulri group, Paleozoic Jangsan formation, Dueumri formation, Janggum limestone formation, Dongsugok formation, Jaesan formation and Mesozoic Dongwhachi formation and Chungyang granite. This Pb-Zn deposit is hydrothermal replacement deposit in Paleozoic Janggum limestone formation. The wallrock alteration that is remarkably recognized with Pb-Zn mineralization at this deposit consists of mainly rhodochrositization and dolomitization with minor of pyritization, sericitization and chloritization. Wallrock alteration is divided into the five zones (Pb-Zn orebody -> rhodochrosite zone -> dolomite zone -> dolomitic limestone zone -> limestone or dolomitic marble) from orebody to wallrock. The white mica from wallrock alteration occurs as fine or medium aggregate associated with Ca-dolomite, Ferroan ankerite, sideroplesite, rutile, apatite, arsenopyrite, pyrite, sphalerite, galena, quartz, chlorite and calcite. The structural formular of white mica from wallrock alteration is (K_0.77-0.62Na_0.03-0.00Ca_0.03-0.00Ba_0.00Sr_0.01)_0.82-0.64(Al_1.72-1.48Mg_0.48-0.20Fe_0.04-0.01Mn_0.03-0.00Ti_0.01-0.00Cr_{0.00As0.01-0.00}Co_0.03-0.00Zn_0.03-0.00Pb_0.05-0.00Ni_0.01-0.00)_2.07-1.92 (Si_3.43-3.33Al_0.67-0.57)_4.00O₁₀(OH_1.94-1.80F_0.20-0.06)_2.00. It indicated that white mica from wallrock alteration has less K, Na and Ca, and more Si than theoretical dioctahedral micas. The white micas from wallrock alteration of Janggun Pb-Zn deposit, Yeonhwa 1 Pb-Zn deposit and Baekjeon Au-Ag deposit, and limestone of Gumoonso area correspond to muscovite and phengite and white mica from wallrock alteration of Dunjeon Au-Ag deposit corresponds to muscovite. Compositional variations in white mica from wallrock alteration of these deposits and limeston of Gumoonso area are caused by mainly phengitic or Tschermark substitution mechanism (Janggun Pb-Zn deposit), mainly phengitic or Tschermark substitution and partly illitic substitution mechanism (Yeonhwa 1 Pb-Zn deposit, Dunjeon Au-Ag deposit and Baekjeon Au-Ag deposit), and mainly phengitic or Tschermark substitution and partly illitic substitution or Na⁺ <-> K⁺ substitution mechanism (Gumoonso area).

• Korean Journal of Heritage: History & Science
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• v.41 no.1
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• pp.5-19
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• 2008

Thirty six samples of Western asia glass vessel shards which were excavated from South Mound of Hwangnamdaechong were each measured for thickness, pore size and specific gravity and analyzed for ten major compositions and thirteen trace elements. The glass samples with colorless, greenish blue and dark purple blue were well classified by principal component analysis(PCA). All glass shards of Hwangnamdaechong belonged to Soda glass system ($Na_2O-CaO-SiO_2$) which have the range of 14~17% $Na_2O$ and 5~6% CaO. The corelation coefficients of (MgO, $K_2O$) and (MnO, CuO) showed above 0.90. The concentrations of thirteen trace elements apparently differentiated from colorless, greenish blue and dark blue glasses. We found that thirteen trace elements were very important indices for studying raw material of glass and the origin of glass making. Colorless glass : The specific gravity is $1.50{\pm}0.04$. Circle or oval circle pores are observed with regular direction in internal zone and the longest one is about 0.35 mm. The raw material of sodium must be the plant ash because sodium glasses contain HCLA(High CaO, Low $Al_2O_3$) and HMK(high MgO, high $K_2O$) and suggested to Sasanian glass. The total amount of coloring agent of colorless glass is below 1 % which is too small to attribute to the color. Greenish blue glass : The specific gravity is $1.58{\pm}0.04$. The fine pores which are 0.1~0.2mm are dispersed in internal zone. Sodium glasses are distributed to HCLA and HMK. Therefore the greenish blue glass also have used plant ash for raw material of sodium with the same as colorless glass. It was also suggested to the glass of Sasanian. The total amount of coloring agent of greenish blue glass is about 4% under the influence of working MnO, $Fe_2O_3$ and CuO. Dark purple blue glass : The specific gravity is $1.48{\pm}0.19$. There are rarely pores in internal zone. They are distributed to HCLA and LMK(Low MgO, Low $K_2O$) and suggested to Roman glass. The raw material of sodium is estimated to natron. The total amount of coloring agents of greenish blue is about 3% by $Fe_2O_3$ and CuO. These studies for western asia glass shards from South Mound of Hwangnamdaechong could be used in the future as the standard data which could be compared with those of other several graves in Korea and dispersed in foreign areas.

• Economic and Environmental Geology
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• v.35 no.1
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• pp.75-95
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• 2002

The Andong pluton in the Andong Batholith is composed of comagmatic plutonic rocks, in which the lithofacies comprise hornblende biotite tonalite in the central paft biotite granodiorite in the marginal paft and porphyritic biotite granite at the topside (noJthea~tern paft) of the pluton. The pluton is petrographically and petrochemically zoned, having more mafic center than margin and topside. Distribution pallern of the lithofacies represents a reverse zoning in the pluton. Modal and chemical data in the pluton show progressive and gradual compositional variations from the centrer via the margin to the topside. Quartz and K-teldspar increase toward the topside of the pluton, whereas hornblende, biotite and color index increase toward the center. The bulk composition in the pluton is also reversely zoned, with high $Si0_2$ and $K_{2}O$ in the topside facies, and high MnO, CaO, $Ti0_2$, $Fe_{2}O_{3}$t, MgO and $P_{2}O_{5}$ in the central facies. The reverse zoning is also evident in higher Cr. V, Ni, Sc and Sr of the more mafic tonalite in the interior. The reversely zoned pluton results from remobilization (resurgence) of the lower more mafic compositional zone into the upper more felsic zones of the pluton modified by thennogravitational diffusion and fractional crystallization. In the initial stages of evolution, the pluton was a petrochemical system that fonned chemical compositional zonation with mafic tonalitic magma in the lower. granodioritic one in the middle and granitic one in the upper paft of the magma chamber. Periodic influxes of more mafic magma from the ba~e resulted in mingling of liquids and redistribution of minerals, and may have triggered the remobilil.ation of the lower compositional zone into the upper more felsic zones.