• Journal of the Korean Geophysical Society
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• v.3 no.2
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• pp.99-112
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• 2000

The Iksan Jurassic Granite shows relatively less fractures and homogeneous rock fabrics, and is one of the most popular stone materials for architectures and sculptures. Almost mutually perpendicular rift, grain, and halfway in the Iksan Jurassic Granite are well known to quarrymen based on its splitting directions, and therefore it should exhibit orthorhombic symmetry. Theoretically, there are 9 independent elastic stiffness coefficients $(C_{1111},\;C_{2222},\;C_{3333},\;C_{2323},\;C_{1313},\;C_{1212},\;C_{1122},\;C_{2233},\;and\;C_{1133})$ for orthorhombic anisotropy. In order to characterize the static and dynamic elastic properties of the Iksan Jurassic Granite, triaxial strains under uniaxial compressive stresses and ultrasonic velocities of elastic waves in three different polarizations are measured. Both experiments are carried out with six directional core samples from massive rock body. Using the results of experiments and the densities measured independently, the static and dynamic elastic coefficients are computed by simple mathematical manipulation derived from the governing equations for general anisotropic media. The static elastic coefficients increase ar uniaxial compressive stress rises. Among those, the static elastic coefficients at uniaxial compressive stress of a 24.5 MPa appear to be similar to the dynamic elastic coefficients under ambient condition. Although some deviations are observed, the preferred orientations of microcracks appear to be parallel or subparallel to the rift, the grain, and the hardway from microscopic observation of thin sections. This indicates that the preferred orientations of microcracks cause the elastic anisotropy of the Iksan Jurassic Granite. The results are to be applied to the effective use of the Iksan Jurassic Granite as stone materials, and can be used for the non-destructive safety test.

• Proceedings of the Petrological Society of Korea Conference
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• 2004.05a
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• pp.104-104
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• 2004

• Proceedings of the Mineralogical Society of Korea Conference
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• 2004.05a
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• pp.104-104
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• 2004

• The Journal of the Petrological Society of Korea
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• v.14 no.1
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• pp.24-37
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• 2005

In this study we examined the geomorphological and geological characteristics of the granite landforms in the Iksan area. Moreover we investigated the source areas of stones which are used to build the Mieruksaji west stone pagoda. Joint is most identifiable geomorphological and geological structure in the Iksan area. Direction of J1 joint appears to be N71°E∼EW, and that of J2 joint ranges N20°W∼N20°E. Cross-pattern joint is predominant in the study area, and linen.-pattern vertical joint is also observed. Tor and corestone are easily found as geomorphological features in the study area. Corestones forming for are almost 2∼3 m across and 2∼3 m or over 5 m high. Their hardness is mainly of hammer bounce. Tower-type and castle-type of for are characteristic in the Mireuksan granites. Other geomorphological features such as tafoni, gnamma are also observed in the study area. Petrographical and geochemical features of the stones used for the Mireuksaji west stone pagoda are compared with those of the granites cropped out nearby, and indicate that the stones from the Mieruksaji west stone pagoda are quite similar to the Mireuksan granites. In the Mireuksan we can easily find lots of old traces for rock cutting.

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.363-381
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• 2006

Mineral compositions of granitic rocks from Geochang, Pocheon, Iksan, and China were obtained by the modal analysis, CIPW norm calculations, and Rietveld quantitative analysis for stone specification of the Geochang granitic rocks. The Geochang granitic rocks show grey to dark in color and medium grained porphyritic texture. They mainly consist of quartz, plagioclase, alkali feldspar, and biotite. Among three different method for determining the mineral compositions of granitic rocks, normative compositions using X-ray fluorescence data are not appropriate for representing real mineral composition. Rietveld quantitative analysis using X-ray powder diffraction data is proved better method to determine exact mineral compositions than modal analysis using microscopic observation. Q-A-P diagram shows that the Geochang granitic rocks are typical granodiorite, whereas the granitic rocks of Pocheon, Iksan, and China are monzogranite, monzogranite to granodiorite, and granodiorite, respectively. Compared to China ones, the Geochang granitic rocks are nearly close to each other in mineral composition.

• Journal of Conservation Science
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• v.27 no.2
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• pp.211-222
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• 2011

The Mireuksaji stone pagoda was built foundation in the reign of King Moo (AD 639) in the Baekje Kingdom of ancient Korea. The stone properties of the pagoda were quarried from Mountain Mireuk, which are medium to coarse-grained light gray biotite granite formed during the Jurassic, and are composed of quartz, feldspar, biotite, muscovite, apatite and allanite. It was strong relatively but became weak from prolonged weathering, and as a result its durability fell to $883kgf/cm^3$ (moderate weathering degree). In the process, cut-off (31%), deletion (57%) and crack (44%) occurred in foundation materials by the influence of bending, shear and compressive force. Hereat, the original materials were treated through a preservation process. As a result, approximately 74% of original materials have been able to be reused, inclusive of 55 materials that were to be partially replaced by new stones. On the other hand, it is inevitable that the other 26% including exterior stones and support-based stones have to be partially replaced by new stones. It implies that there is a need to find stones that are identical or similar to those of the pagoda. Consequently, a lithological study was conducted on stones in quarries located in Iksan and an investigation was made into their properties. The results showed that stones in the Hwangdeung area were most similar to those of the pagoda mineralogically and their properties were most stable.

• Economic and Environmental Geology
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• v.22 no.4
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• pp.381-393
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• 1989

Hydrogeological modelling was performed to evaluate groundwater flow system in Igsan Area. The study area extends over $790km^2$. The geology consists of Jurassic Daebo granite and gneissose granite and Precambrian metamorphic rocks. The capability of pumping yield is the highest in gneissose granite region among them due to comparatively thick weathered zone with thickness ranging from 10m to 25m. The Colorado State University Finite Difference Model was used for the model simulation. The model was divided into 28 rows and 31 columns with variable grid spacing. The model was calibrated under steady-state and unsteady-state conditions. In the steady-state simulation, the model results were compared with measured water table contours in September 1985 with determining hydraulic conductivities and net recharge rates during rainy season. Unsteady state simulation was done to know the aquifer response due to groundwater abstraction. The non- steady state calibration was conducted to determine the distribution and magnitudes of specific yields and discharge/recharge rates during dry season as matching water level altitudes in May 1986. The calibrated model was used to simulate water level vaiation caused by groundwater withdrawal and natural recharge from 1 October, 1985 until 30 September, 1995. The calibrated model can be used to groundwater development schemes on regional groundwater levels, but it cannot be used to simulate local groundwater level change at a specific site.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.201-206
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• 2008

Determining the coefficient of weathering(CW) for stone heritage plays very important role in investigation and conservation plan. In most case, CW is obtained from the empirical relation, which use the difference between sonic velocities of fresh and weathered rocks. In this paper, we measured sonic velocities for the samples from Iksan, Geochang, Wonju, Goesan and Chungju of which our stone heritages are made. We first investigate the uncertainty of velocity by portable measurement by comparing it to lab measurement. There were small difference, but we conclude that the difference is not major. However, the velocity of fresh rock differs significantly among samples: ranging from 3200 to 4400m/s. This cause a lot of error in CW estimation if we use typical fresh rock velocity as of 5000m/s. Thus accurate measurement of the velocity of fresh rock is crucial to CW estimation.

• The Journal of the Petrological Society of Korea
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• v.24 no.3
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• pp.273-289
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• 2015

This study used the petrological features and the whole rock susceptibility characteristics suggest ways to determine the domestic dimension stones and Chinese similar dimension stones. In addition, this study compare the intrusive period by measuring the zircon U-Pb age of these stones. Result of comparing the petrological feature, with the exception of Macheon stone and Boryeong stone to show the differences in mineral composition and texture under a microscope, the domestic dimension stones and Chinese similar dimension stones exhibit substantially the same petrological feature. According to the measurement results for the whole rock magnetic susceptibility, Goheong, Iksan, Pocheon stones are the similar as Chinese dimension stones, and other stones are easily distinguished. The zircon U-Pb age results for Geochang, Iksan, and Pocheon stones are equivalent to the Jurassic Daebo granites and G603, G633, G655 are the Cretaceous granites. Therefore, the domestic dimension stones and Chinese similar dimension stones can be clearly determined by the zircon U-Pb age results.

• Economic and Environmental Geology
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• v.40 no.4
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• pp.375-387
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• 2007

The Iksan Mireuksaji stone pagoda, designated as national treasure No. 11 in Korea, has been in the process of disassembling for reconstruction as part of the cultural heritage conservation program. The pagoda is mainly consisting of granite, which is relatively resistant to weathering. However, it has lost its original rock color due to various contaminants deposited at the surface since it exposed to the atmospheric environment long time. In this research, we categorized the secondary inorganic contaminants into the genetic type, and also quantitatively examined occurrences and types of pollutants in the oxidation area of the pagoda surface in which the area is clearly distinguished by naked eyes. Geochemical behavior of soluble pollutants through reaction experiments are demonstrated, and effective methods of cleaning for the conservation and scientific applicability of the surface cleaner are also studied.