• Economic and Environmental Geology
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• v.52 no.1
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• pp.91-106
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• 2019

The Donghachong tomb from Royal Tombs at Neungsanri is composed of 15 sides including the floor, and the most highly proportion of rock, two-mica granite, are used on the 7 sides (46.6%). Also, augen gneiss consist with another 3 sides (20.0%), and each of the remaining 3 sides (6.7%) are made up of granodiorite, gneissous granite and leucocratic granite, all of which were used to comprise the tabural stone. Meanwhile, the two floors of the burial chamber and the front chamber, are made up of brick-shaped amphibole schist (13.3%). These rocks are occurred in the Buyeo area and their provenance sites are located at the side of Guemgang river. The Memorial Stone for Liu Renyuen in Tang China is a typical augen gneiss showing distinct schistosity and augen texture. This rock has the same petrographic characteristics with the rocks used to build the Donghachong tomb, Sanjikri dolmens and Setapri pagoda in Buyeo. This augen gneiss is distributed from the Jeungsanri in Buyeo to Dukjiri in Gongju as a large scaled rock body, and where currently are the quarries to produce stone aggregates, garden and landscape rocks. Thus, it is highly probable that the site around Buyeo was the source area of augen gneisses since the Bronze Age. However, while augen gneiss is easier to form into shapes it should have disadvantages when it comes to painting on the tomb wall because of their petrographic characteristics of low strength and dark color. Therefore, it is very intriguing to investigate which transportation method the people of Baekje chose with consideration of the distance and terrain, efficiency and convenience.

• The Journal of the Petrological Society of Korea
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• v.26 no.4
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• pp.353-360
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• 2017

The preservation treatment for the outer rampart of Namhansanseong fortress is needed due to partial collapse and separation of stone materials. In this study, we investigated the petrological features of the stone materials used for the outer rampart and estimated their provenances through the geologic survey. Through the above study, the suitable replacement stone in the maintenance of outer rampart were suggested. The stone materials of the above outer rampart consist of the banded gneiss, augen gneiss, granitic gneiss and porphyroblastic gneiss. Among these four kinds of rocks, granitic gneiss is quantitatively the most abundant. Petrological comparisons between stone materials and rocks distributed around the fortress, lead to the conclusion that the above materials are likely to have been delivered from around the fortress. Judging from the results of the comparison on frequency of use and strength characteristics among the above rocks, the granitic gneiss is considered to be suitable for restoration of the outer rampart of the fortress.

• The Journal of the Petrological Society of Korea
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• v.4 no.1
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• pp.61-87
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• 1995

On the basis of lithology, the Precambrian Hongjesa Granitic Gneiss can be locally zoned into granoblastic granitic gneiss, porphyroblastic granitic gneiss, migmatitic gneiss from its center to the marginal part. There are no distinct differences in mineral assemblages by lithologic zoning, but it partly shows the change of mineral assemblage in the adjacent with migmatitic gneiss, thus mineral assemblage can be subdivided into Zone I and Zone II. In terms of mineral compositions, the characteristics of Zone I are coexisting K-feldspar+muscovite+sillimanite. The characteristics of Zone II are (1) breakdown of muscovite, (2) coexisting garnetScordierite, (3) coexisting garnet+cordierite + orthoamphibole. The Buncheon Granitic Gneiss is mainly composed of augen gneiss. In the adjacent area with Honjesa Granitic Gneisses, Buncheon Granitic Gneiss has the mineral assemblage of sillimanite+biotite+K-feldspar+(kyanite). Kyanite occurs as relict grains in the Buncheon and Hongjesa Granitic Gneissess. Kyanite shows anhedral to subhedral form and coexists with sillimanite in only one of these samples. Garnet from a migmatitic gneiss (Zone 11) has relatively high $X_{Fe}$ value in core and rim. Garnet from a porphyroblastic granitic gneiss(Zone I) has relatively homogemeous core but compositionally-zoned rim. Biotites show various colour from greenish-brown, brown to reddish brown at maximum adsorption. Also, the Ti, and Mg content in biotites increases from Zone I to Zone II. The plagioclases shows the chemical composition of $Ab_{84}An_{16}$ -$Ab_{70}An_{30}$ (oligoclase) in Zone I and $Ab_{70}An_{30}$ -$Ab_{50}An_{50}$(andesine) in Zone 11. These variations indicate that the gneisses in the study area experienced a upperamphibolite facies. The presence of kyanite as relict grains indicates that the metamorphic rocks in this area exprienced a high-temperature/medium-pressure type metamorphism, followed by high-temperaturellow-pressure metamorphism. Metamorphic P-T conditions for each gneiss estimated from various geothermobarometers and phase equilibria are 698-$729^{\circ}C$/6.3-11.3 kbar in augen gneiss, 621-$667^{\circ}C$/1.0-5.4 kbar in migmatitic gneiss, and 602-$624^{\circ}C$/1.9-3.4 kbar in porphyroblastic granitic gneiss. These data suggest that the study area was subjected to a clockwise P-T path with isothermal decompression (dP/dT=about 60 bar/$^{\circ}C$).

• Economic and Environmental Geology
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• v.37 no.2
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• pp.225-234
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• 2004

The Chungung-dong 5-storied pagoda (Treasure No. 12) in the nnm, Korea was studied on the basis of petrological weathering and deterioration diagnosis. Frontal part of the pagoda is looked out on the N30$^{\circ}$W. Constitution rocks of this pagoda show augen gneiss and biotite granite. Host rock of the pagoda was highly exfoliation and discoloration, therefore most rock-forming minerals were altered to the clay minerals due to the mineralogical and chemical weathering. Open cavity and rock surface occur partly green and black patchs because of contamination by algae, lichen and moss, and the lower part of the pagoda is transition to the some weeds. This biological problems are need for cleaning and chemical treatments. For the structural stability, the pagoda is rebuilt without open gap between the each rock materials. All iron plates eliminate from the difference gap of the rock materials, and properly conservation treatments need to be repaired petro-filler for stone cultural properties and water curtain for the humidity attenuation of the ground.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.183-193
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• 1998

This study was designed, firstly, to determine the mineralogical and chemical characteristics of some rock aggregates, secondly, to offer interrelationships between those and mechanical properties, and thirdly, to evaluate their suitability for concrete aggregates. Mineralogical, chemical, physical and mechanical characteristics of the studied rock aggregates indicate that granite from BJ quarry and banded gneisses from KB. HI and SK quarry, and quartzite from the Hongcheon riverside are not proper to cement concrete aggregates because of quartz's potential possibility of alkali-silica reaction, and limestone in SY quarry is proper to asphalt concrete aggregates owing to dolomite causing alkali-carbonate reaction. Augen gneiss and diorite from KB and SA quarry, respectively, are to be not suitable for concrete aggregates because of biotite contents, but augen gneiss in HI quarry and gneisses in Hongcheon riverside are proper to concrete aggregates because of mineralogical and mechanical characteristics.

• Economic and Environmental Geology
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• v.3 no.3
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• pp.169-176
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• 1970

Kubong Gold Mine is located in Kuryongri, Sayang-myun, Chungyang-gun, Choongchung-Namdo.(latitude $36^{\circ}24^{\prime}N$. longitude $126^{\circ}45^{\prime}30^{{\prime}{\prime}}E$) The mine was begun to work soon after the inhabitants of this village had accidently discovered the outcrops in April 1908. It is one of the largest gold mines in Korea which produces 4,500 tons of crude ore a month. The geology in the area consists of granitic gneiss, banded gneiss, augen-gneiss, mica schist, limesilicate of Pre-Cambrian series and sedimentary rocks(sandstones & conglomerates) of Daedong series. Basic dikes intrude the former formations. The country rock of the ore deposit is a group of the metamorphic rocks mentioned above. Gold-silver bearing quartz vein contains small amounts of pyrite, chalcopyrite, arsenopyrite, galena and sphalerite in which gold and silver occur as native state. The vein strikes $N30^{\circ}{\sim}60^{\circ}E$ and dips $20^{\circ}{\sim}50^{\circ}S$ and the average width of the vein is estimated 1 to 1.5m. Average grade of ore is Au:6~8gr/t and Ag:5~6gr/t. The ore shoot continues from the outcrop to the depth of -1760ML with dip of $20{\sim}25^{\circ}$ and strike extension reaches to 400m at the depth of -1440 ML and to more or less 200m at below. Highgrade of ore vein was found at the lowest level of the ore shoot at the time of recent field survey at the end of August 1970. Its average grade was estimated as Au:20gr/t and its width 1~2.5M in average. A series of futher prospecting for other new ore shoot or parallel veins are urgent and crosscut prospecting along the horizontal level is strongly recommended.

• Nuclear Engineering and Technology
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• v.15 no.1
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• pp.23-32
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• 1983

In the previous studies on Rb-Sr geochronology, Gyeonggi Massif was known as the oldest rock in Korea Peninsula but the detailed sequence of geochronology was not studied yet. In the present study, some of whole rock isochrons considered here can be geochronologically grouped as follows: The ages of leucocratic gneisses at Yangpyeong, and augen and banded gneisses at Anyang show 2200 to 2300 m.y. which may represent the time of the Massif formation or an igneous intrusion. The age of the granite gneiss distributed in Yangpyeong area shows about 1400 m.y., which apparently represents the intrusion time of the gneiss. The age of the extremely altered metamorphic rock shows about 500 m.y., which may represent the time of a Caledonian orogenic event probably with hydrothermal activities. The other episodic ages of 800 to 900 m.y. which was widely observed through the Massif, may represent the ages of Precambrian igneous activities or regional metamorphism in the Massif. It seems to be reasonable that the ages of 120 to 270 m.y. show the times of Mesozoic and Late Palaeozoic Plutonisms in the Massif.

• The Journal of the Petrological Society of Korea
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• v.1 no.1
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• pp.1-24
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• 1992

Precambrian metamorphic rocks of the Gapyeong-Cheongpyeong area consist of banded gneiss, augen gneiss, leucocratic gneiss, quartz schist and quartzite, together with minor intercalations of serpentinite, amphibolite and marble. Mineral assemblages of meta-sedimentary rocks are classified into three types: sillimanite-free; sillimanite-bearing; and sillimanite+K-feldspar-bearing assemblages. Compositions of metamorphic phases depend on the type of mineral assemblages. In particular, the Ca contents of plagioclase and garnet are high in sillimanite-free assemblges. Kyanite occurs in three samples, and coexists with sillimanite in one sample. The presence of kyanite indicates that metamorphic rocks of the study area have experienced the Barrovian type metamorphism. Peak metamorphic conditions estimated from various geothermobarometers and phase equilibria are 618-674$^{\circ}C$ and 6.5${\pm}$2.0 kbar for sillimanite-free assemblages, and 701-740$^{\circ}C$ and 4.4${\pm}$0.8 kbar for sillimanite-bearing assemblages, respectively. Furthermore, a clockwise P-T-time path is deduced for the study area, based on the following observations: (1) the polymorphic transition of kyanite to sillimanite, (2) the occurrence of sillimanite and K-feldspar belonging to the upper amphibolite facies, and finally (3) the retrograde metamorphism characterized by muscovite-, chlorite-, and actinolite-bearing assemblages.

• Economic and Environmental Geology
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• v.10 no.1
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• pp.19-35
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• 1977

The study area is located in between Hacheonri and Weolgulri, Jecheon-gun where the formations of Okcheon group and Chosun group come in contact and the stratigraphy and geological age of the Okcheon group have been debated among previous workers. The dolomitic limestone which distributed at Cheongam and Dumusil is clarified as the Hyangsanri dolomite formation and the quartzite distributed at Cheongam and Howeunri as Taehyangsan quartzite formation. The newly named Soorumsan schist interbedded in the Great Limestone Series was previously classified Seochangri formation. It is also classified that the formation formerly named as Seochangri was divided into newly named Manji schist which seems to be correlated to Kemyeongsan and Munjuri formation. The formation formerly named as Buknori is clarified as Hwanggangri formation. The Samtaesan formation has been clarified as the lower and upper limestone beds which belong to the Great Limestone Series. The area divided into two groups, that is, Okcheon system of Pre-cambrian age occupies western part and the Great Limestone Series of Chosun system of Cambro-Ordovician age eastern part of this area. Okcheon system consists in ascending order of Manji schist, Hyangsanri dolomite, Taehyangsan quartzite, Munjuri schist, and Hwanggangri formation of meta-tillite. The Great Limestone Series of Chosun group consists in ascending order of lower limestone, Soorumsan schist, Hoosanri quartzite and upper limestone formations. Busan augen gneiss seems to be igneous origin. Unmetamorphosed shale interbed can be traced in the Soorumsan schist. Previous study (Kims, 1974) reveals that meta-volcanic rocks are distributed from south to north along contact zone of the Okcheon and Chosun groups, and it has been confirmed that the meta-volcanics crop out continuously from the adjacent southern quardrangle into the southern part of the area studied, intruding along the fault zone between the Okcheon and Chosun groups which seems to be upthrust as in the area south. This evidence coincides with Kims' work (1974) which states that the Precambrian Okcheon group is largely overturned and thrusted over the Chosun group.