• Economic and Environmental Geology
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• v.56 no.6
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• pp.697-714
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• 2023

The Tracksite of Cretaceous Dinosaurs and Pterosaurs in Jeongchon, Jinju was discovered in late 2017 during the construction of the Ppuri industry complex. This site is a natural heritage site with a high paleontological value, as it preserves fossils of various types of dinosaurs, pterosaurs, and animal traces at a dense concentration. In this study, we surveyed that physical weathering such as joint, crack, scaling, exfoliation, and fragmentation occurred through field research in the fossil site, and conducted basic research on conservation science to reduce the damage. To this end, among the eight levels identified after excavation, the rocks of Level 3, which yielded a large number of theropod footprint fossils, and Level 4, which yielded pterosaur footprint fossils, were analyzed for material characteristics and evaluation of the effectiveness of consolidation and adhesion. This results showed that the rocks in the Level 3 stratum were dark gray siltstone and the rocks in the Level 4 stratum were dark gray shale, which contained a large amount of calcite and were composed of quartz, plagioclase, mica, alkali feldspar, and other clay minerals, which are likely to be damaged by rainfall under external conditions. As a result of conducting an artificial weathering experiment by dividing the probationary sample into four groups: untreated, consolidation treatment, anti-swelling treatment, and adhesive treatment, the consolidation and the swelling inhibitor showed an effect immediately after treatment, but did not show a blocking effect under a freezing-thawing environment. The adhesive showed that the adhesive effect was maintained even under freezing-thawing conditions. In order to preserve the fossil sites at Jeongchon in the future, in addition to temporary measures to block the inflow of moisture, practical measures such as the construction of protective facilities should be prepared.

• Journal of the Korean Ceramic Society
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• v.32 no.1
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• pp.71-82
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• 1995

The weathered two-mica granite is widely distributed in Korea and called a kind of ground rock for kaolin. The major minerla compositions are consist of this quartz, feldspar, mica and clay mineral. At present, only a small portion of this granite is used as the material for the low-grade tile industry due to the low S.K. value and the high contents of impurities such as Fe2O3 and FeO. The low S.K. value is caused by feldspars not weathered to clay minerals. The refinement of this thus has been required for the recent shortage of the resources of high-grade one. This paper concerns an optimum hydrothermal treatment condition to refine the low-grade weathered two-mica granite of which impurities are feldspar mineral and Fe2O3. FeO components in using for the main material of ceramic industry. And then, from this result, we tried to fine out the basic formation mechanism of clay mineral from feldspar etc and develope the effectual utilization method of this.

• Journal of the Korean Geotechnical Society
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• v.21 no.1
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• pp.15-27
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• 2005

In this paper, a method reasonably predicting soil water characteristic curve of domestic weathered granite soils was suggested, based on the test results obtained through experiments. In other words, a method to estimate the parameters of Fredlund and Xing's equation using an ANN (artificial neural network) was proposed. The particle size distribution, compacted water content and void ratio were used as input data in the ANN model for predicting the parameters, since it was found that these basic soil properties affect the parameters obtained from the test results and the fitting results of SWCC. The network model proposed in this study to obtain the parameters of Fredlund and Xing's SWCC equation produced reliable predictions, and the precision of the prediction results from the proposed method was high, in comparison with the prediction results of other methods.

• Journal of the Korean Geotechnical Society
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• v.27 no.2
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• pp.27-34
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• 2011

This study analyzes the determination of slope failure model due to changes in ground condition followed by heavy rainfall. With a simulated rainfall system, the movement of a slope from the rainfall penetrating the unsaturated soil is investigated with respect to various conditions of pore-water pressure, earth pressure, and moisture content, considering rainfall duration and permeability. As a result of the experiment, under the persistent precipitation of 50mm/h, pore-water pressure of weathered granite soil started increasing from the upper position of the slope, and then the pressure increased in middle and bottom portion of it in timely manner. In case of the pore-water pressure of the standard soil, the pressure increased from the middle and bottom portion, and the cause of the different order is suspected to be the difference in permeability between the standard soil and the weathered granite soil. As an outcome, though the result may vary by each foundation, there exists a danger of slope failure not only when the cumulative rainfall is more than 120 mm but also when the saturation level amounts to 60~75%.

• The Journal of Engineering Geology
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• v.16 no.3 s.49
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• pp.293-300
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• 2006

The groundwater movement in the west costal landfill area was analyzed by measuring N value by Standard Penetration Test, coefficient of permeability by falling head method, linear structure analysis by Digital Elevation Method, groundwater flow direction and rate by flowmeter logging due to tidal variation in the each borehole. The coefficients of permeability of the weathered zone and of the marine deposit showed similar values although some values of weathered zone show smaller values than those of the marine deposit. The major groundwater flow and rate in the marine deposit observed as east-west direction due to tidal variation, but on the other hand it was observed as N45E in weathered zone which is the major direction of the linear structures in the area. 2 hours delayed changes of the groundwater flow direction was observed during the 24 hours observation, and it seems to be a travel time of the tidal wave which cause the continuous change of the hydaulic gradient of the groundwater.

• Journal of Conservation Science
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• v.22
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• pp.121-134
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• 2008

The mechanism of stone exfoliation and its cause in relation to chemical weathering by soluble salt were studied. Chemical, mineralogical and physical analysis was performed in exfoliation samples from stone monuments. The representative salt is gypsum in the exfoliation samples. In order to understand the salt reaction, stone samples(tuff and granite) were treated with two type of the salt, gypsum and sodium sulfate, which have different solubility. The capillary water uptakes are slight increased in impregnated with Na2SO4 and weathering simulation of two rock types. It means that the rock is deteriorated in the near of the surface by $Na_2SO_4$. $CaSO_4{\cdot}2H_2O$ bring out the thicker exfoliation than $Na_2SO_4$ because it is penetrated into the deeper zone and amount of accumulated salt is more abundant in the inner part than in the near of the surface. The exfoliation was formed in the tuff by salt treatment and 30cycle of weathering simulation, but there are not significant symptoms of exfoliation in the granite by same condition. This result was caused by the different capillary water uptakes and porosity of the rocks. In the tuff, salt solutions are penetrated into the inner part due to its high capillary water uptakes and porosity but the granite, which has low value relatively, can be formed thinner exfoliation.

• Journal of Conservation Science
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• v.32 no.1
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• pp.21-32
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• 2016

Animal glue is a traditional material used extensively as adhesive and binder in mother-of-pearl, wooden structure, traditional painting, etc. Analysis of animal glue is usually performed with IR(infrared spectroscopy) based on the IR absorption of functional group. But, it has a limitation in confirming animal glue when a sample consists of several materials because of overlapping of the absorption band. Py/GC/MS(pyrolysis/gas chromatography/mass spectrometry) is a useful tool in analyzing the constituent of polymeric materials like animal glue by identifying their pyrolysate with very small amount of sample. In this study, confirmation of animal glue in a Dancheong sample was tried with this method. Characteristic pyrolytic compounds of animal glue and tung oil used in Dancheong were identified. Dancheong sample painted with Noerok as a coloring material, animal glue and tung oil was prepared and it was possible to find characteristic peaks of animal glue after thermal degradation and artificial weathering experiment. From this, we found that animal glue can be detected using py/GC/MS in cultural heritage samples consisting of several materials and in different condition. IR was also tried to analyze Dancheong sample and the results were compared with those of py/GC/MS for the detection of animal glue.

• Geophysics and Geophysical Exploration
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• v.15 no.1
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• pp.1-7
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• 2012

To evaluate methods of determining near-surface shear-wave velocities (${\nu}_s$), we derived dispersion curves of Rayleigh waves generated by both passive and active sources in Chuncheon, Korea. Microtremors were recorded for 5 minutes in each of four triangular arrays with radii of 5 ~ 40 m. Those data were analyzed using the Spatial Autocorrelation method. Rayleigh waves were also generated by a hammer source and recorded in the same area for 2 s using 24 4.5-Hz geophones. Multichannel Analysis of Surface Waves was applied to those data. Velocity spectra were derived with relatively high signal-to-noise ratios in the frequency ranges of 7 ~ 19 and 11 ~ 50 Hz for the microtremors and synthetically generated Rayleigh waves, respectively. The resultant dispersion curves were combined as one and then input to inversion to derive shear wave velocities that were compared with a lithology log from a nearby well. Shearwave velocities in the top soil and soft-rock layers are almost constant with values of 221 and 846 m/s, respectively; while the inverse-modeled ${\nu}_s$ increases linearly in the gravelly sand, cobbles, and weathered-rock layers. If rock type is classified based on shear-wave velocity, the inversion-derived boundary between weathered-rock and soft rock may be about 5 m deeper than in the well log.

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.355-361
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• 2006

Artificially crushed sands occupy approximately 30 percent of the total consumption in South Korea. The demand for the crushed sands is expected to rise in the future. Most manufacturers use granitic rocks to produce the crushed sands. During the manufacturing process, fine fractions (i.e., sludges or particles smaller than 63 microns) are removed through the process of flocculation. The fine fraction occupies about 15% of the total weight. The sludges are comprised of quartz, feldspars, calcite, and various kinds of clay minerals. Non-clay minerals occupy more than 75 percent of the sluges weight, according to the XRD semi-quantification measurement. Micas, kaolinites, chlorite, vermiculite, and smectites occur as minor constituents. The sludges from Jurassic granites contain more kaolinites and $14{\AA}$-types than those from the Cretaceous ones. The chemical analysis clearly shows the difference between the parent rocks and the sludges in chemical compositions. Much of colored components in the sludges was accumulated as the weathering products. Particle size analysis results show that the sludges can be categorized as silt loam in a sand-silt-clay triangular diagram. This result was for her confirmed by the hydraulic conductivity data. In South Korea, the sludges remained after crushed sand production are classified as an industrial waste because of their impermeability, and which is caused by their high silt and clay fractions.

• Journal of Conservation Science
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• v.28 no.3
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• pp.247-256
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• 2012

Amber has been used as gemstones and artifacts from the period of the Three Kingdoms or earlier, which are discovered in the process of excavation now. It is, however, very difficult to discuss the importing route and circulation of amber because there are no informations available on the provenance. In this study, we acquired the IR spectra of ambers originating from 5 different locations. We also monitored the change of characteristic IR peaks by artificially aging the ambers under heat, light and heat with oxygen, respectively. As the aging proceeded, the intensity of C=O band and O-H band increased, however, the bands related with C=C bond decreased. There needed some modifications in the discerning scheme because some peak disappeared with aging; yet, it was still possible to discern different ambers largely. Therefore, it is expected that the scheme can be used practically by appraising its applicability to the real amber relics excavated.