• Title/Summary/Keyword: lithology

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A Proposal of Geological Investigation method Concomitant with Ground Construction : In the Light of Southeast Korean peninsula. (건설공사에 수반되는 지질조사 방법에 대한 제안 : 한반도 동남부 지역을 중심으로)

  • 류춘길;김성욱;이현재;정성교
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.87-92
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    • 2002
  • Engineering geological studies were conducted for igneous rocks in southeast Korean peninsula. The purpose of the study is to establish zoning in view of engineering geology in ground construction. For engineering geological implication, lithology, lineament structure and discontinuities were surveyed and analysed. Using constructed data, We compared geological and engineering geological characteristics and made out the detailed engineering geological map. The map responses engineering characteristics such as weathering degrees, discontinuity systems of different rock types.

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Lithology and Geology of Deokjeok Island, Western Gyeonggi Massif, Central Korea (서부 경기육괴에 위치한 덕적도의 암상과 지질)

  • Aum, Hyun Woo;Kim, Yoonsup;Cheong, Wonseok
    • The Journal of the Petrological Society of Korea
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    • v.22 no.4
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    • pp.263-272
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    • 2013
  • We investigated the lithology and petrography of granites and metasedimentary rocks in Deokjeok Island at the western margin of the Gyeonggi massif. The major lithology comprises the biotite granite that intrudes all other types of rocks. A minor amount of mylonitized porphyritic granite crops out along the southeastern coast. Metasedimentary rocks in the north are further divided into: (1) sheared quartzite-schist to the northeast; and (2) relatively less-deformed, low-grade metasedimentary rocks to the northwest. The former contains quartz grains showing undulatory extinction and subgrain aggregates as well as minor amount of primary chlorite and biotite in the muscovite-rich matrix. Metamorphic condition belongs to the greenschist facies or the biotite zone. On the other hand, the latter unit consists of meta-conglomerate, meta-sandstone, meta-pelite, and black slate. Regardless of the lithology, the intensity of deformation apparently increases eastward to develop the flow banding of quartz in the shear zone.

An analysis of rock mass characteristics which influence the choice of support

  • Bednarek, Lukasz;Majcherczyk, Tadeusz
    • Geomechanics and Engineering
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    • v.21 no.4
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    • pp.371-377
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    • 2020
  • There are currently three common methods for selecting excavation supports in Polish hard coal mines. While many factors are considered when choosing appropriate support, these do not include layering or cracking in the excavation ceiling. Although global classifications of rock mass are rarely used in hard coal mines, they are utilised much more frequently during the construction of underground structures such as tunnels. Mining classifications of rock mass have been developed (e.g., in Germany) and they rely on a number of factors but are often related to local mining and geological conditions. This paper discusses the selected findings of a study carried out on seven excavation sites with diverse mining and geological characteristics. Based on the collected data, two indicators were developed to describe rock mass quality. The first indicator is referred to as the roof lithology index WL and describes the quality of the excavation roof in terms of its layering and lithology. The second indicator is the crack intensity factor n and represents the amount of cracks in an excavation's roof. The correctness of the developed indicators was supported by reliable data from the excavation in which the designed support did not fulfill its task but was changed at a later stage, after calculating the proposed indicators.

Relationship Analysis between Lithology, Geological time and Geothermal Gradient of South Korea (남한지역의 암상 및 지질시대별 지온경사율 관계 분석)

  • 김형찬;이사로;송무영
    • Economic and Environmental Geology
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    • v.35 no.2
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    • pp.163-170
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    • 2002
  • The purpose of this study is to analyze the relationship between geology and geothermal gradient in South Korea using GIS. For the analysis, 352 temperature logging wells were constructed to spatial database and the relationships beween geothermal gradient and geological time and lithology were analyzed using the overlay the wells layer and 1:1,000,000 scale geological map layer. The average of the geothermal aradient of South Korea is 29.34$^{\circ}C$/km. In the geologic sequence, Cenozoic strata has 39.7$0^{\circ}C$/km, Mesozoic strata has 30.63$^{\circ}C$/km , Paleozoic strata has 22.32$^{\circ}C$/km, Proterozoic strata 23.15$^{\circ}C$/km geothermal gradient value. In the lithological aspect, plutonic rocks 33.96$^{\circ}C$/km, sedimentary rocks have 24.78$^{\circ}C$/km and sedimentary and volcanic rocks have 26.85$^{\circ}C$/km geotermal gradient value. The result can be used to develop geothermal energy and hot spring as a reference.

A Study on Transportation Characteristics of Debris dependent on Geologic Conditions (지질조건에 따른 사태물질 이동특성 고찰)

  • Chae Byung-Gon;Kim Won-Young;Lee Choon-Oh;Kim Kyeong-Su;Cho Yong-Chan;Song Young-Suk
    • The Journal of Engineering Geology
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    • v.15 no.2 s.42
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    • pp.185-199
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    • 2005
  • Properties of sliding materials are dependent on the lithology because debris is the product of rock weathering processes. In order to characterize transportation behavior of debris dependent of debris types, this study selected 26 debris flows over three areas composed with different rock weathering types and topographic conditions. Analyses of lithology, weathering, and topographic characteristics were performed by detailed field survey. Based on the field survey data, transportation behavior of debris was studied at the aspect of the relationship of grain size and volume of debris as well as topographic conditions. According to the study results, change of slope angle is very influential factor on runout distance of debris among the topographic factors. Because the sliding velocity and the energy of debris are frequently changed and more irregular on an undulating slope, the unout distance of debris is larger than that of an uniformly dipping slope. Runout distance of debris is also influenced by volume and grain size of debris. Volume of debris in the gabbro is four or five times larger than that of the granite area because it is controlled by the lithology. Considered with grain size distribution, runout distance of debris is longer in the gabbro area which is composed with irregular grain size bearing large corestones than that in the medium grained granite area.

Stratigraphy, Lithology and Diagenetic Mineral Facies of the Tertiary Yeonil Group (제 3기 연일층군의 층서, 암상 및 속성 광물상)

  • Noh Jin Hwan
    • The Korean Journal of Petroleum Geology
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    • v.2 no.2 s.3
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    • pp.91-99
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    • 1994
  • In the Heunghae area, genetic relationships among sedimentary facies, lithology, stratigraphy and diagenetic mineral facies of the Yeonil Group, are discussed. Conglomerate and sandstone of lower to middle parts of the Yeonil Group contain considerable amounts of volcaniclastic sediments, which were derived from the Tertiary volcanics exposed in the western margins of the sedimentary basin. A new stratigraphic division of the Yeonil Group into the Chunbuk and Pohang Formations is proposed on the basis of sedimentary facies, lithologic characteristics including volcaniclastic feature, and the presence of a key bed of siliceous mudstone overlying the Chunbuk Formation. Diagenetic mineral facies largely depend on the lithology and composition of sediments. Heulandite, smectite, calcite, and opal-CT are commonly found as diagenetic minerals in the Yeonil Group. Among these authigenic minerals, heulandite occurs as the coarse- grained main cement in conglomerates and sandstones of the Chunbuk Formation. Formation of the zeolite cement is favored by partial volcaniclastic lithology of the Chunbuk Formation. Smectite composition and diagenetic mineral facies such as heulandite and opal-CT may reflect that the Yeoil Group has undergone a shallow rial temperature ranging $40{\~}60^{\circ}C$.

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