• Korean Journal of Soil Science and Fertilizer
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• v.6 no.3
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• pp.141-152
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• 1973

The mineralogical studies of the eleven sub-soil samples derived from granite, granodiorite, diorite and arkose sandstone, taken from apple orchards in the province of Kyungsangbukdo, Korea are made to investigate the relationships between the mineral weathering, soil forming processes and mineralogical composition. The fine sand fraction (less than 0.2mm) and the clay fraction (less than 2 micron) are dispersed with the shaker after hydrogen peroxide treatment for the removal of organic matter, and separated from each suspension by gravity sedimentation. The fine sand are observed by mineral microscope and the clay are observed by X-ray diffraction patterns, differential thermal analysis curves and infrared spectrum. The outline of the results are as follows. 1. The primary minerals ; Quartz, changed-feldspar, plagioclase, alkali-feldspar are dominant in almost all samples, and some samples contain an appreciable amount of hornblende, biotite, muscovite and plant opal. There are also those samples which contain very small quantity of pyroxene group, tourmaline, epidote, cyanite, magnetite, volcanic glass and zircon. They are mainly derived from weathering products of granite, granodiorite, diorite, arkose or its mixtures. 2. All samples contain expanding or nonexpanding $14{\AA}$ minerals, illite and kaolin minerals, and some samples contain chlorite, cristobalite, gibbsite, and those primary minerals as quartz and feldspar, but the quantities vary according to the parent matrials. 3. Non-expanding $14{\AA}$ minerals may be dioctahadral vermiculite which sandwiches gibbsite layer or chlorite in between layer lattices. 4. As for clay minerals, montmorillonite was principal component in the samples derived from weathering products of arkose sandstone and tertiary. Minerals which are derived from weathering products of arkose have kaolin minerals and vermiculite as their principal component, and minerals derived from weathering products of acidic rock group are generally classified into two groups, the kaolin mineral group, and the kaolin minerals and vermiculite group.

• Korean Journal of Heritage: History & Science
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• v.56 no.4
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• pp.160-189
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• 2023

The Cheonjeon-ri petroglyph is inscribed with shale formation belonging to the Daegu Formation of the Gyeongsang Supergroup in the Cretaceous of the Mesozoic Era. This rock undergoes thermal alteration to become hornfels, and has a high hardness and dense texture. Rock-forming minerals have almost the same composition as quartz, alkali felspar, plagioclase, calcite, mica, chlorite and opaque minerals, but calcite is rarely detected in the weathered zone. The petroglyph forms a weathered zone with a certain depth, and there is a difference in mineral and chemical composition between weathered and unweathered zones, respectively. The CaO contents of the weathered zone were reduced by more than 90% compared to that of the unweathered zone, because calcite reacted with water and dissolved. As a result of calculating the surface weathering depth for the petroglyph with the transmission characteristics of X-rays, depth of the parts in falling off and exfoliation showed a depth of about 0.5 to 1 mm, but the weathering depth in most areas was calculated to be about 3 to 4 mm. This can be proved by the contents and changes of Ca and Sr. The surface discolorations of the petroglyph are distributed with different color density, and the yellowish brown discoloration is alternated with a thin biofilm layer, showing a coverage of 79.6%. Therefore, periodic preservation managements and preventive conservation monitoring that can effectively control the physicochemical and biological damages of the Cheonjeonri petroglyph will be necessary.

• The Journal of the Petrological Society of Korea
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• v.9 no.2
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• pp.53-69
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• 2000

To reveal the origin of the Chuncheon nephrite deposit, radiogenic isotopes of Sr and Pb, stable isotopes of 0 and H, and rare earth elements concentrations were analyzed. Such geochemical data were integrated to track the stepwise changes during the various ore formation stages. All the samples from the nephrite deposit have significantly low 0 isotopic ratios compared with the marble from which they had been formed, which reflects the very important role of the crustal circulating water with low 6180 and 6D in every stage of ore formation. There were progressive decrease of 6180 and 6D during the genesis of Chuncheon nephrite deposit. Newly formed minerals during the ore formation reveal disequilibrium with existing minerals in the respect of 0 isotope, which suggests that the ore-forming fluid of circulating water origin was involved with significant water-rock ratios in every step of ore formation process. The ore samples have Sr and Pb isotopic ratios similar to the values of Kyeonggi gneiss complex within which the deposit is located, which also suggests the important role of crustal circulating water in the genesis of the deposit. In conclusion, all the geochemical data support that major portion of the ore-forming fluid of Chuncheon nephrite deposit was derived ultimately from the surface water of meteoric origin. The meteoric water supplied Sr and Pb through leaching the rocks surrounding the ore deposits.

• Journal of Conservation Science
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• v.26 no.4
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• pp.349-360
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• 2010

The Yeongsheon Sinwoldong three-storied stone pagoda (Treasure No. 465) composed mainly of drusy alkali-granite. The major rock-forming minerals are biotite, quartz, amphiboles, orthoclase and plagioclase. Yellowish brown and black discoloration are formed at the eight sculpture Buddha of the stylobate. A broken rock fragments in the roof material were repaired using epoxy resin and cement mortar in the past. As a result of the infrared thermography analysis from the pagoda, cracks and exfoliation were not serious. Also, P-XRF analysis showed that concentration of Fe (mean 5,599ppm) and S (mean 3,270ppm) were so high in yellowish discoloration parts. Black discoloration area was detected highly Mn (mean 2,155ppm) concentration around the eight sculpture Buddha of the stylobate. The main reason for these are inorganic contaminants from disengaged rock ingredient and organic contaminants from withered plant body. Degree of physical weathering is relatively high in the southern and northern side. The eastern and western side had similar with weathering condition. The northern and eastern side were serious discoloration and biological weathering relatively. Therefore, we suggest that the pagoda need to do cleaning of biological contaminant and conservation treatment to weakened materials of rock and long term monitoring.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.79-85
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• 1991

This study reports on the physical and chemical properties of the whole soils (<2mm) derived from five major rocks of granite, granite-gneiss, limestone, shale, and basalt in Korea. The properties were considered from the kind and frequency distribution of rock-forming minerals in the parent rocks. In particle size distribution, sand fractions were high in the soils from granite-gneiss, silt fractions mainly, in the residual soils from limestone, shale, and basalt. And clay fractions were particularly high in the colluvial soil from limestone and the old alluvial soil from basalt. pH, extractable Ca and Mg, and cation exchange capacity of the soils derived from limestone might be considered to be high due to the presence of sand and/or silt-sized calcite and dolomite inherited from the parent rocks. However, the soils derived from granite and granite-gneiss, being abundant in feldspars, quartz, and micas, showed a tendency to the contrary. A soil from shale composing of high quartz tended to have pH. extractable Ca, base saturation, and low exchangeable Al. In total element analysis, the soils derived from parent rocks with high contents of (i) orthoclase and micas, (ii) biotite, primary chlorite, and augite, and (iii) carbonate minerals and plagioclase as a rock-forming mineral showed a tendency to decrease the contents of $K_2O$, $Fe_2O_3$ and MgO, and CaO in comparison with those of their parent rocks.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.3
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• pp.145-152
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• 2002

The composition of primary minerals in the rocks and secondary minerals of clay fractions of the soil developed on the cinder cones in the foot of Halla Mt., Jeju Island was investigated. The effects of parent materials on the physico-chemical properties and mineralogical characteristics were evaluated by XRD, DTA with the chemical composition of $H^+$ saturated clays. The main rock-forming minerals of a residual cinder cones were plagioclase with subsidiary minerals of hematite, gibbsite and quartz in the red cinder cone and of augite, quartz, feldspars and olivine in black cinder cone. It is demonstrated that ignition loss and sesquioxides content were higher in the red cinder soil than black cinder, which was resulted in the intermittent eruption of volcanic activity. For the chemical analysis of whole soils, $SiO_2/Al_2O_3$ ratio was increased from 2 to 3, but Ignition loss is decreased and $K_2O$ content are very low with increasing the soil depth in regard to the composition and kinds of clay minerals. No clay formation from micas mineral were in volcanic ashes. Dominant clay minerals of the cinder cone soils as a black and red cinder cone soil were allophane with some quartz and feldspars, while vermiculite, illite, kaolin were coexisted as a subsidiary minerals. But the red cinder cones soils had more hematite and gibbsite of the clay fractions than the black soils with magnetite. The exothermic pick of DTA at about $660^{\circ}C$ for cinder cone soils might be corresponded the oxidation magnetite to hematite reation. With regarding to the compositions of mineral detected by X-ray diffractogram and the properties of minerals by D.T.A thermogram, the dominant clay mineral was allophane of the cinder cone soils with some ferrous compounds, red colour of the cinder cone soils which are originated in hematite.

• Economic and Environmental Geology
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• v.17 no.1
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• pp.1-15
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• 1984

The tin and tungsten deposits are embedded around the age unknown Buncheon granite gneiss which intruded the Precambrian schists, gneiss and amphibolites in Bonghwa-Uljin area. Pegmatite dike swarm developed intermittently about 4km along the southern border of Buncheon granite gneiss at Wangpiri area. Thickness of pegmatite dikes range from 0.5 to 15m. Pegmetite is consisted of quartz, microcline, albite, muscovite and frequently topaz, tourmaline, garnet, fluorite, fluorapatite and lepidolite. Pegmatite dikes are greisenized, albitized and microclinized along dike walls. Cassiterites are irregularly disseminated through the intensely greienized and albitized parts of the pegmatite. Cassiterite crystals are mainly black to dark brown and contain considerable Ta and Nb. Average Ta and Nb contents of the four cassiterite samples are 5300 and 3400 ppm. The Ssangjeon tungsten deposits is embedded within the pegmatite dike developed along the northern contact of Buncheon granite gneiss with amphibolite. This pegmatite developed 2km along the strike and thickness varies from 10 to 40m. Mineral constituents of the pegmatite are quartz, microcline, plagioclase, muscovite, biotite, tourmaline and garnet. Ore minerals are ferberite and scheelite with minor amount of molybdenite, arsenopyrite, pyrrhotite, pyrite, chalcopyrite, sphalerite, galena, pentlandite, bismuthinite, marcasite, and fluorite. Color and occurrence of quartz reveals that quartz formed at three different stages; quartz I, the earliest milky white quartz formed as a rock forming mineral of simple pegmatite; quartz II, gray to dark gray quartz which replace the minerals associated with quartz I; quartz III, the latest white translucent quartz which replace the quartz I and H. All of the ore minerals are precipitated during the quartz II stage. Fluid inclusion in quartz I and II are mainly gaseous inclusions and liquid inclusions are contained in quartz III and fluorite. Salinities of the inclusion in quartz I and II ranges from 4.5 to 9.5 wt. % and 5.1 to 6.0 wi. % equivalent NaCl respectively. Salinities of the inclusion in fluorite range from 3.5 to 8.3 wt. % equivalent NaCl. Homogenization temperatures of the inclusion in quartz I, II and III range from 415 to $465^{\circ}C$, from 397 to $441^{\circ}C$ and 278 to $357^{\circ}C$. Data gathered in this study reveals that tin and tungsten mineralization in this area are one of prolonged event after the pegmatite formation around Buncheon granite gneiss.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.279-288
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• 2009

Mineral compositions of the Gyeonggi Bay surface sediments were determined using the high resolution X-ray diffractometer and Siroquant v. 3.0 program. Surface sediments are composed of rock forming minerals (quartz 63.8%, plagioclase 12.9%, alkali feldspar 11.7%, muscovite 4.3%, amphibole 1.2%, biotite 0.5% on average), clay minerals (illite 2.4%, chlorite 1.4%, kaolinite 0.4%) and carbonate minerals (calcite 0.1%, aragonite 0.3%). Coarse sediments are high in the northern, southern and central parts of the study area, whereas fine sediments are high in the northern and southern parts of the central area. Coarse sediments have relatively a high quartz content in the northern part, and relatively high plagioclase and muscovite contents in the southern part of the study area. In the southern part and the northern part of central area, fine sediments have relatively a high illite content, and chlorite and kaolinite contents, respectively.

• Journal of Conservation Science
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• v.33 no.4
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• pp.241-254
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• 2017

The Stone Guardian and Memorial Tablets from the Muryeong Royal Tomb are composed of the same kind of plutonic igneous rocks, the so-called hornblendite. Color of the rocks show greenish gray, and both of them occurred with medium-grained granular texture. The rock-forming minerals composed mainly of amphibole and plagioclase. Magnetic susceptibility of the Stone Guardian is 0.15 to 0.63 (mean $0.42{\times}10^{-3}SI\;unit$), the King's Stone Memorial Tablet is 0.11 to 0.38 (mean $0.24{\times}10^{-3}SI\;unit$) and the Queen's Stone Memorial Tablet ranges from 0.10 to 0.33 (mean $0.18{\times}10^{-3}SI\;unit$). The rocks of the artifacts are hard to find in the Gongju area. Large scaled out crop of hornblendite is not distributed, but found in many places that the form of dike. The lithology and occurrences indicate that the artifacts are made of plutonic rock rather than dike. Reddish brown and pale brown contaminants, are also distributed on the surface of the Stone Guardian and Memorial Tablets. The reddish brown color is due to Fe oxide, and the pale brown color occurs due to the elution of Ca. The reddish brown contaminants are influenced by the internal components of the rock and oxidation of burial iron accessories. In contrast, the pale brown contaminants are considered to have flown from the carbonate materials used in the Royal Tomb, with a little added Fe oxide. Physical and chemical deterioration operate intricately in the Stone Guardian and Memorial Tablets. Physical deterioration is extremely rare and chemical deterioration is stable except for a part of the Stone Guardian and the front of the Queen Stone Memorial Tablet.

• Journal of the Mineralogical Society of Korea
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• v.29 no.4
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• pp.239-254
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• 2016

The Hwangto cave is a sea cave which is located near shore in the Taeha-ri, Ulleung Island, being composed of the reddish tuff wall rock, the topic of this study, and the trachyte ceiling rock. The chemical compositions of the red tuff layer are 49.81-63.63% of $SiO_2$, 13.05-24.91% of $Al_2O_3$, 2.67-5.82% of $Fe_2O_3$, 2.87-6.92% of $Na_2O$, 2.37-3.85% of $K_2O$, 0.55-0.81% of $TiO_2$, 0-0.53% of MnO, 0.39-1.75% of MgO, and 0.60-1.40% of CaO with a pH ranging from 4.5 to 8. The reddish tuff are composed of 23.7-39.4% of anorthoclase, 16.9-33.3% of sanidine, 15.8-26.1% of illite, 5.1-9.0% of hematite, 0-3.7% of goethite, 6.9-9.9% of titanium oxide, and 0.9-9.5% of halite in mineral composition. Although it only includes anorthoclase, sanidine, and illite as major minerals, there can be additional vitric minerals that could not detected by the XRD. The mineralogy and textures of the tuff layer indicate that it became reddish due to the formation of amorphous palagonite and the oxidation of the iron as a heat from the trachytic lava affects the underlying tuff to altered. This iron oxides are enriched in the palagonite, or form microcrystalline or amorphous minerals. We thus suggest that the red tuff layer was generated by the combination of the thermal oxidation involved in the trachytic lava flow on the tuff layer, the palagonitization of the matrix of the tuff, and the oxidation of iron-bearing minerals.