• Journal of Conservation Science
• /
• v.17 s.17
• /
• pp.73-82
• /
• 2005

The Bunhwangsaseoktop is the oldest stone brick pagoda in Silla Period. The pagoda body is made by piling small brick-shaped stones trimmed from black andesite and the first-story core has a shrine, which is made by granite. In 1915 it was repaired on a large scale, but now is severely damaged. Many kind of the stone decay like flaking, granular disintegration have occurred especially on the granite surface of the pagoda. In this study have been investigated the stone decay type and its cause in relation to efflorescence on the body part. Various analysis show that the deterioration on the granite is due to the same materials that lead to efflorescence on the body stone surface. The soluble salt like sodium nitrate, calcium sulfate and sodium sulfate come from white joint mortar. This salt solution is recrystallized in the outside of the pagoda, but most of them flow down with rain. In This process the porous granite absorbes the dissolved salts with moisture into the inside by capillary action. In order to reduce this problem, therefore, white joint moral is changed with other less soluble materials. And it is necessary to take steps to prevent water from seep into the inside of the stone, because this water dissolves the white joint mortar.

• Geophysics and Geophysical Exploration
• /
• v.4 no.1
• /
• pp.8-18
• /
• 2001

To delineate the inhomogeneities including fractures and to estimate the freshness of rock borehole radar consisting of the reflection and tomography methods, and GPR surveys were conducted at a granite quarry mine. The borehole reflection survey using the direction finding antenna was also conducted to get the spatial orientations of reflectors. 20 MHz was adopted as the central frequency for the borehole radar reflection and tomography surveys and 100 MHz was for GPR. Through the interpretation of borehole reflection data using dipole and direction finding antenna as well as GPR images, which are good agreement with each other, we could determine the orientation of the major fractures in three dimensional way. Parts of travel time curves of tomography data showed the anisotropy, which is uncommon in granite quarry. By comparing the tomography data and TeleViewer images, the anisotropy effect in this area are closely related to fine fissures aligned in the same direction. The area confined by the two fractures, MF2 and MF5, might consist of the most fresh granite in the surveyed area, which was concluded from the borehole radar tomography, and GPR images as well as the distribution of anisotropy.

• Economic and Environmental Geology
• /
• v.34 no.1
• /
• pp.105-117
• /
• 2001

The characteristics of hydrogeochemistry and fluorine distribution in drinking groundwater from limestone and granite were studied in the Keumsan-Wanju area, where major important fluorite-deposits are distributed. The hydrochemical properties of groundwater from studied area arc commonly characterized as $Ca-HC0_3$ water type. However, some of the groundwater samples collected from Jurassic and Cretaceuus granites belong to $Ca-Na-HC0_3 and Na-HC0_3$ type, respectively. The contamination of drinking groundwater by minewater from the nearby fluorite deposits is not found yet. However, groundwater having high F contents up to 1].4 mgll, which is higher than the drinking water limit, is found from the wells located in Cretaceous granite. The tluorine contents in groundwater generally increase with increasing well depth. The concentrations of F in the groundwater show a positive relationship with the values of Na, $HC0_3, Cl. Si0_2$, pH, whereas a negative relationship with Ca. The positive correlation of F-concentrations to major elements ($Si0_2$, Na, CI) and trace elements (Li, B, Rb) may suggest that the groundwater come from the decomposition of tluoride-bearing silicate minerals within highly differentiated granitic rocks, Therefore, wells for drinking water should not be developed or should be drilled within shallow level in the Cretaceous granite region to reduce the F contents in the groundwater.

• Economic and Environmental Geology
• /
• v.40 no.2 s.183
• /
• pp.251-262
• /
• 2007

The purpose of this research is to develop a Geological Information System(GIS) in order to store, manage and display geochemical data observed from references of recently domestic granite. There is still no use in geochemical and mineralogical information such as REE(rare earth element), trace elements, mode data(modals or mineral composition) and major elements. Therefore, we need to construct the standardized database system for the analytical data of granites through the verification of its data in South Korea. To construct the information system for geochemical and mineralogical information of granites in South Korea. Firstly, we collected the existing research data related digital map data. Secondly, we extract granite polygons to digital geological map and convert the polygon to points in South Korea. Thirdly, we considered both database schema and symbols of REE elements, trace elements, modal data and major mineral. Fourthly, we carried out all sorts of process to build granite database for GIS statistic analysis and visualization.

• Journal of Conservation Science
• /
• v.5 no.1 s.5
• /
• pp.20-40
• /
• 1996

For obtaining the basic data for establishing plan on the conservation of the Gameunsa 3-story and Naweonri 5-story Pagodas located at the Kyeongju city, the characteristics of the rock and weathering phenomena have been investigated. The former consists of quartz-rlch granite containing small amount of biotite, and the latter of alkali granite with abundant perthite, These rock phases are nearly identical to the marginal phase of medium-grained hornblende-biotite granodiorite and alkali granite respectively, which are distributed around the Kyeongju city. The rock weathering may be governed mainly by chemical weathering of feldspar following physical segregation of quartz grains and pervasive moss. The feldspar easily dissolve In the solution with pH<7 to precipitate clay mineral such as a kaolinite as a secondary phase on the feldspar surface. However, the chemical weathering of feldspar may continue when the surface is washed by the rain according to removal of the reprecipitated phase. On forwarding, the weathering may be greatly Influenced by the acid rain. Exfoliation and weathering along igneous lineation resulting in exfoliating along the structural line are the characteristic weathering phenomena. Also the secondary small cracks are irregularly developed on the rocks due to different strain on places by the overall structural unbalance of the pagodas. Along these cracks, the rain water intrudes deeply into the rocks and weathering occurs intensively compared to other parts. Weathering may be artificially promoted by the grinding or sculpturing when the pagodas were made. Because it may influence on the physical properties of the rocks as well as destruct the surface of the feldspar crystals, the major constituents of the rocks, it results in providing the environment of easy chemical weathering along time. For conservation, the pagodas must be structurally balanced by compacting the soil basement and supplementing rocks on the destroyed part. On the exfoliated part it is better not to be artifically treated as using cementing material. But the cracks may be filled up by cementing material to avoid the intrusion of acidic water. To supplement the rocks on the destroyed part, it may be better to use similar rock phases from identical biotite granite and alkali granite masses around the Kyeongju city.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.7 no.1
• /
• pp.59-67
• /
• 2004

This study was carried out to select proper species for early stage replantation in granite forest roads cut-slope. From one to fourteen year elapsed forest roads in eight regional areas of Gyeongsang-do and Jeolla-do, sample plots were selected, and their vegetations and environmental factors were investigated. Soil organic matter, total nitrogen, soil moisture content, and bulk density in the granite weathering soils were below 0.4%, 0.03%, 12.4%, and above 1.2g/$cm^3$, respectively. The result indicated that the soil was not good for plant growth. The environmental factors affecting distribution of species in the granite forest roads were the elapsed year, elevation, and cut-slope aspect. Invaded species with high frequency in the forest road cut-slope ordered Pinus densiflora, Lespedeza bicolor, Rubus crataegifolius, Alnus hirsuta, Youngia denticulata, Patrinia villosa, Artemisia princeps var. orientalis, Zanthoxylum schinifolium, and Dactylis glomerata. Herbs seeded in earth stage such as Dactylis glomerata, Eragrostis curvula, Festuca arundinacea, Lespedeza sp., and Amorpha fruticosa had changed into perennial herbs and shrubs such as Youngia denticulata, Patrinia villosa, Aster scaber, Patrinia scabiosaefolia, Melica onoei, Astilbe chinensis var. davidii, Chrysanthemum zawadskii var. latilobum, Pueraria thunbergiana, Stephanandra incisa, and Clematis apiifolia, and had changed into plants such as Artemisia princeps var. orientalis, Artemisia keiskeana, Miscanthus sinensis, Pinus densiflora, Rhododendron mucronulatum, Rubus crataegifolius, and Zanthoxylum schinifolium according to elapsed year of forest roads. Leguma such as Lespedeza sp., Pueraria thunbergiana, Amorpha fruticosa, etc., herbs such as Artemisia keiskeana, Artemisia princeps var. orientalis, Chrysanthemum zawadskii var. latilobum, Miscanthus sinensis, etc., and woody plants such as Pinus densiflora, Rubus crataegifolius, Rhododendron mucronulatum, etc., with foreign herbs were considered as proper species for replantation in granite forest road cut-slope.

• Economic and Environmental Geology
• /
• v.46 no.2
• /
• pp.93-104
• /
• 2013

Daejiguksaptapbi (Tapbi) is a memorial stele which is inscribed with personal history of a state preceptor, Daejiguksa Beopkyeong. The Tapbi comprises tortoise-shaped pedestal, dragon top and body stone, and the body stone is remained in 255 pieces by excavation in Samcheonsaji temple site of Seoul. The Tapbi is composed of tuffaceous breccia for the body, coarse-grained pink feldspar granite for the pedestal and fine-grained granite for the top. As a result of geological survey to find a rock provenance of the Tapbi rock, the tuffaceous breccia is found in the banks of Gangwha straits, and the pink feldspar granite and fine-grained granite are found around the temple site in Mt. Bukhansan. Each rock shows similarities to the Tapbi in lithology and mineralogy. Also, geochemical data of major, some trace and rare earth elements verify their cognation in each rock type. It can be interpreted that the provenance of the body stone is distant as Gangwha area, and the provenance of the pedestal and top stones are near the temple site. The results can be utilized to restore the Tapbi by using the same rocks.

• Korean Journal of Agricultural Science
• /
• v.12 no.1
• /
• pp.86-100
• /
• 1985

In order to investigate the strength characteristics of weathered granite soils in unsaturated state, the five physically different weathered granite soils and the common soil (sandy loam) were examined. The disturbed and the undisturbed material were prepared for triaxial compression test. The following conclusions were drawn from the study; 1. Dry density of the undisturbed soil samples was lower than maximum dry density determined from the compaction test and it showed the higher value at the well graded soil. 2. The failure strength of the samples decreased with the increase of moisture content of the soil and these results were highly pronounced at the common soil sample having a good cohesive property. 3. On weathered granite soils, the cohesion was lower measured and the internal friction angle highly, the decrease rate at internal friction angle with increase of moisture content of the soil was more significant than that of cohesion 4. The modulus of deformation of the samples decreased with increase of moisture content of the soil and these phenomena were highly pronounced at the weathered granite soils than common soil. 5. The failure strength of the samples increased with in crease of confining pressure and effect of confining pressure on failure strength was highly significant at the lower moisture content of the soil.

• Economic and Environmental Geology
• /
• v.50 no.3
• /
• pp.181-193
• /
• 2017

Mn-Fe phosphate mineral complexes included within the pegmatite are observed at Jurassic Cheolwon two-mica granite in Gyeonggi Massif, South Korea. The genetic evolution between the Cheolwon two-mica granite and pegmatite, and various trend of Mn-Fe phosphate minerals is made by later magmatic, hydrothermal, and weathering process based on mineralogical, geochemical analysis. The Cheolwon two-mica granite is identified as S-type granite, considering its chemical composition (metaluminous ~ peraluminous), post-collisional environment, low magnetic susceptibility, and existence of biotite and muscovite. The K-Ar age (ca. 153 Ma) of pegmatite is well coincident with age of the Cheolwon two-mica granite ($151{\pm}4Ma$). It indicates that these two rocks are originated from the same magma. Pegmatite indicates the LCT geochemical signature, and was classified as muscovite-rare element class / Li subclass / beryl type / beryl-columbite-phosphate subtype pegmatite. The triplite $\{(Fe^{2+}{_{0.4}},Mn_{1.6})(PO_4)(F_{0.9})\}$ is dominant phosphates in later magmatic stage which partly altered to leucophosphite $\{KFe^{3+}{_2}(PO_4)_2OH{\cdot}2H_2O\}$ and jahnsite $\{(Fe^{3+}{_{0.7}},Mn_{2.3})(PO_4)_2OH{\cdot}4H_2O\}$ by hydrothermal alteration. In particular, near fractures, the triplite has been separatelty replaced by the phosphosiderite ($Fe^{3+}PO_4{\cdot}2H_2O$) and Mn-oxide minerals during weathering stage.

• Economic and Environmental Geology
• /
• v.51 no.6
• /
• pp.521-529
• /
• 2018

This study was conducted to investigate the natural origin of fluorine contained in the rocks within the Eulwangsan area via petrological and mineralogical analyses. The main geology of the Yongyudo Eulwangsan area is Triassic biotite granite. Biotite granite and mylonite are the major rock types containing fluorine at high levels (up to 1,700 and 2,400 mg/kg for biotite granite and mylonite, respectively). In the case of the biotite granite, a high concentration of fluorine can be contributed to fluorite, and the results of microscopic analyses show that the fluorite was observed as small veinlets filling cleavages and micro-fractures within alkali-feldspars and plagioclases, or observed together with quartz in ore veins, indicating the secondary formation of fluorite by hydrothermal fluids. In mylonite, on the other hand, a high fluorine concentration is attributable to sericite. Microscopic analyses revealed that the boundary between sericite and surrounding quartz was not clear, the sericite occurred filling the micro-fractures of quartz and encapsulating small quartz cataclasts. These results indicate that the sericite was also formed as a result of hydrothermal alteration. Consequently, it is speculated that the high fluorine level in the rocks of the Eulwangsan area of Yongyudo is of natural origin due to hydrothermal processes.