• Title/Summary/Keyword: Korean granite

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K-Ar ages and geochemistry of granitic rocks in the northeastern geongsang basin (북동부 경상분지의 화강암류에 대한 지구화학 및 K-Ar 연대)

  • 김상중
    • Economic and Environmental Geology
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    • v.32 no.2
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    • pp.141-150
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    • 1999
  • The granitic rocks are distributed in the northeastern Gyeongsang basin, and are subdivided into the Youngduk, Younghae, Jangsadong and Onjeong granite. Based on the chondrite normalized patterns of REE by primitive mantle, the Jangsadong granite is more negative Eu anomaly than other granites. On the patterns of trace and rare earcth elements normalized by primitive mantle, Sr, P, Nd, Sm and Ti contents of t도 Youngduk and Younghae granites are higher than those of Jangsadong and Onjeong granites. Based on K-Ar ages, the Youngduk granite is 166.5 Ma for biotite, Younghae granite is 158.7 to 178.0 Ma for hornblende, Jangsadong granite is 113.8 to 118.4 Ma for K-feldspar and hornblende, and Onjeong granite is 67.4 Ma for biotite. Thus, geochemical and geochronological results suggest two plutonic episodes :the Youngduk-Younghae granites and Jangsadong-Onjeong granites suggest two plutonic episodes : the Youngduk-Younghae granites and Jangsadong-Onjeong granites. Jurassic plutonism cooled faster than Cretacous plutonism in the study area.

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A case study of large-scale slope failure in Granite - Andesite contact area (화강암-안산암 접촉부 대규모 사면의 붕괴 사례 연구)

  • 이수곤;양홍석;황의성
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.503-508
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    • 2003
  • In this study, we peformed ahead a field geological investigation, boring investigation for slope stability analysis in large scale slope failure area. But the geological stratum was not clearly grasped, because ground was very disturbed by large scale Granite intrusion. Furthermore, the existing test data was not pertinent to the large scale Granite intrusion site like here. Therefore, various kind of field test were performed to grasp clearly for geological stratum. And the results of back analysis, various kind tests used to slope stability analysis.

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창원지역 화강암의 수리분산 특성

  • 김무진;함세영;황한석;김문수
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.187-190
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    • 2001
  • This study is concerned with the hydrodispersive characteristics of granite in Changwon area. A single-well injection/recovery tracer test was conducted to determine longitudinal dispersivity of the granite, using sodium chloride tracer The dispersivity values obtained from the injection phase are 0.48 m (for between PW-1 and OW-3) and 0.72 m (for between PW-1 and OW-4). That obtained from the recovery phase is 0.68 m. The result of the tracer test indicates that the anisotropy and heterogeneity of the granite and the direction of flow.

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A Geochemical Study of the Alkali Granite in the Kyeomyeongsan Formation (충주지역 계명산층 내에 산출하는 알카리 화강암의 지구화학적 연구)

  • Kim, Jin-Seop;Park, Meong-Eon;Kim, Gun-Soo
    • Economic and Environmental Geology
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    • v.31 no.4
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    • pp.349-360
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    • 1998
  • The alkali granite occurred as small stock and dyke is distributed in the Kyeomyeongsan Formation in the vicinity of the Chungju city. Geochemical characteristics in major and trace element of alkali granite in the Kyeomyeongsan Formation indicate that the alkali granites are peralkaline and have similar geochemical features to the A-type alkali granite. The rock enriched in HFSE such as Zr, Nb, Y, REE etc. According to the discrimination diagram the alkali granites mostly belong to the within-plate granite field, and to the $A_1$ group of A-type granite. This suggests that they might be emplaced in a extentional rift environment. The alkali granites are characterized by remarkably high total REE content, and enriched, relatively flat to somewhat HREE-depleted patterns with large negative Eu anomaly. The Sm-Nd age of the alkali granite is $338{\pm}30Ma$ with ${\varepsilon}_{Nd(t)}$ beings -7.3 to -8.5. On the basis of the geochemical studies the source magma was derived from a enriched mantle-like source and had a few or clearly interaction with sialic continental crust. In conclusion, the alkali granitic rock of the Kyeomyeongsan Formation might be formed from the high F peralkaline magma that was emplaced in continental rift environment, and generated at the early Carboniferous.

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Geochemical Study on Foliated Granites in the Damyang-Jinan area (담양(潭陽)-진안(鎭安)사이에 분포(分布)하는 엽리상화강암류(葉理狀花崗岩類)에 대(對)한 암석화학적(岩石化學的) 연구(硏究))

  • Kim, Cheong-Bin;Kim, Yong-Jun;Hong, Sei-Sun
    • Economic and Environmental Geology
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    • v.23 no.1
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    • pp.87-104
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    • 1990
  • Foliated granites between Damyang and Jinan are subdivided into Daegang foliated granite, Foliated hornblende biotite granodiorite, Sunchang foliated granodiorite, Foliated two mica granite and Samori foliated granite by mineral and texture. From EPMA data of the foliated granites following results are achieved. Composition of plagioclase are correspond to andesine, oligoclase and albite in Foliated hornblende biotite granodiorite, Sunchang foliated granodiorite and other foliated granites, respectively. And amphiboles are calcic hornblende in Foliated hornblende biotite granodiorite, and riebeckite in Daegang foliated granite. In differentiation index(D. I.) and Larsen index(L. I.), Daegang foliated granite, Foliated two mica granite and Samori foliated granite which belong to granite are 83.12-95.54 and 25.86-29.05 and Foliated hornblende biotite granodiorite and Sunchang foliated granodiorite of diorite to granodiorite are 54.99-78.54(D. I.) and 6.48-21.01(L. I.). Harker and AMF diagrams plotted from foliated granites show that the granites are product of calc alkali rock series orignated from co-magma. Characteristic foliation of foliated granites fromed by ductile deformation at deep zone of dextral strike slip fault. Foliated granites are considered as a series of differentiated product of Triassic Igneous activity of Songrim disturbance. According to REE, (La/Lu) and Eu/Sm, Foliated hornblende biotite granodiorite and Sunchang foliated granodiorite are correspond to granodiorite, and other foliated granites are monzo-and syeno-granite. Foliated granites having 0.20-0.01 of Em/Sm ratio are plutons emplaced by the tectonic setting in continents and continental margin.

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Petrogeochemistry of Granitic Rocks Distributed in the Geumsan District, Korea (금산지역에 분포하는 화강암류의 암석지구화학)

  • Chin, Ho-Ill;Min, Kyoung-Won;Chon, Hyo-Taek;Park, Young-Seog
    • Economic and Environmental Geology
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    • v.28 no.2
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    • pp.123-137
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    • 1995
  • The Mesozoic Geumsan granitic rocks of various composition are distributed in the Geumsan district, the central part of the Ogcheon Fold Belt. About 40 ore deposits of $CaF_2{\pm}Au{\pm}Ag{\pm}Cu{\pm}Pb{\pm}Zn$ are widely distributed in this district and are believed to be genetically related to the granitic rocks. Based on their petrography and geochemistry, the granitic rocks in this district can be classified into two groups ; the Group I( equigranular leucocratic granite, porphyritic biotite granite, porphyritic pink-feldspar granite, seriate leucocratic granite) and the Group II(seriate pinkfeldspar granite, equigranular alkali-feldspar granite, equigranular pink-feldspar granite, miarolitic pink-feldspar granite, equigranular biotite granite). Interpreted from their isotopic dating data and geochemical characteristics, the Group I and the Group II are inferred to be emplaced during the Jurassic(~184Ma), and the Cretaceous to the early Tertiary period(~59Ma), respectively. Both Group I and Group II generally belong to magnetite-series granitoids. The Cretaceous granitic rocks of Group II are more highly evolved than those of the Jurassic Group I. The Rb-Sr variation diagram suggests that the granitic rocks of the Jurassic Group I and of the Cretaceous Group II be evolved mainly during the processes of fractional crystallization and partial melting, respectively.

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Gravity Exploration Inferring the Source Granite of the NMC Moland Mine, Jecheon, Chungbuk (충북 제천 NMC 몰랜드 광산의 관계 화성암에 대한 중력탐사)

  • Shin, Young Hong;Yoo, Bong Chul;Lim, Mutaek;Park, Yeong-Sue;Ko, In Se
    • Economic and Environmental Geology
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    • v.47 no.2
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    • pp.107-119
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    • 2014
  • NMC Moland mine, which is classified as a contact replacement or skarn deposit, has been interpreted to have been formed by Daebo igneous activity which intruded into the Joseon Supergroup, because it is quite closely located to Jecheon granite. However, an alternative interpretation was recently suggested that the mine could be related with the hydrothermal fluid originated from Cretaceous granitic rocks, bringing about skarnization and Mo mineralization. Here we present an interpretation on the source granite of the mine based on the gravity exploration: the gravity anomaly, unlike the surface geology, shows that the Muamsa granite could be the related granite of the mine, because its hidden subsurface structure is expected to be more widely extended to surrounding area of the mine and deeper than the Jecheon granite.

Research on Physical Changes Based on Drying After Downpour Penetration of Floor Finishing Use Granite Stone (호우로 인한 바닥 마감용 화강석 침수 후 건조상태에 따른 물성변화에 관한 연구)

  • An, Ki-Won;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.173-174
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    • 2015
  • This research takes granite stone based floor finishing exposed to concentrated downpouring and observes the material's physical changes, adhesiveness, compressive strength under wet conditions. The results of the experiments shows that elution of sulfide mineral can occur when granite stones are exposed to downpour, but short term exposure shows little physical changes to the material. This indicates that if post maintenance is properly enacted, long term usage of granite stone materials is also possible.

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Petrological Classification and Provenance Interpretation of the Sungnyemun Stone Block Foundation, Korea PDF icon (숭례문 육축 구성석재의 암석학적 분류와 원산지 해석)

  • Jo, Young Hoon;Lee, Chan Hee;Yoo, Ji Hyun;Kang, Myeong Kyu;Kim, Duk Mun
    • Korean Journal of Heritage: History & Science
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    • v.45 no.3
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    • pp.174-193
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    • 2012
  • This study focused on distribution ratio of stone properties based on material characteristic analysis, provenance presumption and transportation route interpretation of the Sungnyemun stone block foundation. The stone block foundation is composed of pinkish granite (56.0%), reddish granite (4.5%) and leucocratic granite (26.2%) of original stones and pinkish granite of new stones(13.3%). The rock-forming minerals for granites are consisted mainly of quartz, alkali-feldspar, plagioclase and biotite, and are similar geochemical evolution trend of major, rare earth, compatible and incompatible elements. Therefore, it is clear that the rocks are genetically same origin. As a result of magnetic susceptibility measurement, the pinkish and reddish granite of original stones and pinkish granite of new stones showed normal distribution around about 4.00(${\times}10^{-3}SI\;unit$). But the leucocratic granite of original stones were confirmed ilmenite series under about 1.00(${\times}10^{-3}SI\;unit$). As a result of provenance interpretation and transportation route analysis based on the petrological results, the provenance of pinkish granite and reddish granite of original stones are presumed the north slope in Namsan mountain and Naksan mountain. Also, the leucocratic granite of original stones and the pinkish granite of new stones are strongly possible furnished from the south and north slope in Namsan mountain and Naksan mountain, respectively.

The Acid Buffer Capacity of a Horizons in Young Residual Entisols in Korea

  • Zhang, Yong-Seon;Sonn, Yeon-Kyu;Lee, Gye-Jun;Han, Kyung-Hwa;Cho, Hee-Rae
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.6
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    • pp.519-524
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    • 2013
  • pH buffer capacities (pHBC, $cmol_c\;kg^{-1}\;pH^{-1}$) of 6 residual Entisols derived from granite, granite-gneiss, limestone, sandstone, shale, and basalt in Korea were studied. Soil acidity may become a problem if the soil pH is reduced to critical levels when nutrient cycles are unbalanced (especially N, C and S). The relation between the pHBC and the physico-chemical properties of the 6 soils was also studied. In the A horizons of all the soils except Euiseong series developed from sandstone, the contents of clay, organic matter and cation exchange capacity (CEC) were higher than those of C horizon, but bulk density and pH were lower than C horizon. Clay content of Euiseong series decreased with soil depth, which might be caused by the elluviation. The soils developed from granite, granite-gneiss and sandstone have a higher $SiO_2$ content than those developed from basalt and limestone. The contents of $Fe_2O_3$ and MgO were high in the soils from developed from basalt, limestone and shale comparing with the soils from granite, granite-gneiss and sandstone. The soils from basalt and limestone showed higher values of ignition loss than those from the other parent rocks. The pHBC of the soils was ranged from 1.8 to 3.2 $cmol_c\;kg^{-1}\;pH^{-1}$ showing as follows : basalt, limestone > shale, granite-gneiss > granite sandstone.