• Economic and Environmental Geology
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• v.35 no.4
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• pp.355-368
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• 2002

The multi-storied Daewonsa stone pagoda (Treasure No. 1112) in the Sancheong, Korea was studied on the basis of deterioration and geological safety diagnosis. The stone pagoda is composed mainly of granitic gneiss, partly fine-grained granitic gneiss, leucocratic gneiss, biotite granite and ceramics. Each rock of the pagoda is highly exfoliated and fractured along the edges. Some fractures in the main body and roof stones are treated by cement mortar. This pagoda is strongly covered with yellowish to reddish brown tarnish due to the amorphous precipitates of iron hydroxides. Dark grey crust by manganese hydroxides occur Partly, and some Part coated with white grey gypsum and calcite aggregates from the reaction of cement mortar and rain. As the main body, roof and upper part of the pagoda, the rocks are developed into the radial and linear cracks. Surface of this pagoda shows partly yellowish brown, blue and green patchs because of contamination by algae, lichen, moss and bracken. Besides, wall-rocks of the Daewonsa temple and rock aggregates in the Daewonsa valley are changed reddish brown color with the same as those of the pagoda color. It suggests that the rocks around the Daewonsa temple are highly in iron and manganese concentrations compared with the normal granitic gneiss which color change is natural phenomena owing to the oxidation reaction by rain or surface water with rocks. Therefore, for the attenuation of secondary contamination, whitening and reddishness, the possible conservation treatments are needed. Consisting rocks of the pagoda would be epoxy to reinforce the fracture systems for the structural stability on the basements.

• The Journal of the Petrological Society of Korea
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• v.16 no.3
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• pp.116-128
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• 2007

Detailed geological mapping, petrographic study, analyses of geochemistry and magnetic susceptibility, and K-Ar dating were carried out in order to determine the origin, age, and stratigraphic implications of granitic rock fragments in the pyroclastic rocks, SE Jinhae city, southern part of the Gyeongsang Basin. As a result, it was found that the area is composed of volcanics and tuffaceous sediments of the Yucheon Group, Bulguksa granites, pyroclastics bearing granitic rock fragments, $basalt{\sim}basaltic$ andesite, and rhyolite in ascending stratigraphic order. The granitic rock fragments in the pyroclastic rocks are divided into granodiorite and biotite granite, which have approximately the same characteristics as the granodiorite and the biotite granite of the Bulguksa granites, respectively, in and around the study area including color, grain size, mineral composition, texture (perthitic and micrographic textures), intensity of magnetic susceptibility (magnetite series), and geochemical features (calc-alkaline series and REE pattern). This leads to the conclusion that the rock fragments originated from the late Cretaceous Bulguksa granites abundantly distributed in and around the study area, but not from the basement rocks of the Yeongnam massif or the Jurassic granites. Based on relative and absolute ages of various rocks in the study area, the pyroclastics bearing granitic rock fragments are interpreted to have erupted between 52 and 16 Ma, i.e. during the Eocene and early Miocene. These results indicate that the various volcanisms, acidic to basic in composition, occurred after the intrusion of the Bulguksa granites, contrary to the general stratigraphy of the Gyeongsang Basin. Very detailed and cautious mapping together with relative and absolute age determinations are, thus, necessary in order to establish reliable stratigraphy of the Yucheon Group in other areas of the Gyeongsang Basin.

• Economic and Environmental Geology
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• v.23 no.3
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• pp.329-342
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• 1990

The purpose of this study is to clarify the nature of the differentiation and petrogenesis of igneous rocks in comparison with experimental results based on petrological and geochemical criteria. Study area is composed of the Precambrian granitic gneiss complex, Triassic meladiorite and biotite granodiorite, Jurassic biotite granite, and Cretaceous quartz porphyry. According to the data of EPMA, the clinopyroxene and orthopyroxene of meladiorite come under salite and hypersthene, respectively. Such results suggests that meladiorite is incipient differentiated products of basic magma under slow cooling condition. The petrochemical data of variation diagram of major element oxides vs. silica and of trace element oxide vs. silica, AMF triangle diagram and trace elements suggests that igneous rocks of study area are plutonic rocks belong to calc alkali rock series of the source of comagma intruded-emplaced in the order of meladiorite, biotite granodiorite and biotite granite by fractional crystallization of magma.

• Economic and Environmental Geology
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• v.28 no.6
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• pp.571-577
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• 1995

Several acid-sulfate clay deposits associated with silicic magmas occur in the Haenam area of the southwestern part of Korea. Geology of the studied area consists of tuffs, granitic rocks, quartz porphyry, rhyolite, andesite and sedimentary rocks. The granitic rocks and quartz porphyry intruded tuffs and sedimentary rocks. The rhyolite and tuffs around the mines have undergone hydrothermally weak or strong alteration. Gold contents with major and trace elements have been determined for a total of sixty-seven specimens of fresh igneous rocks, wall rocks and minerals such as dickite and alunite by graphite furnace atomic absorption spectrometer and inductively coupled plasma. Gold is enriched in the alunite vein and the silicified zone, but is depleted in dickites and hydrothermally altered rocks with dickite of the Seongsan deposit. Gold is especially concentrated near the faults or conjunction area of two faults. High content of gold is shown in the mineral assemblages of alunitequartz- pyrite in the alunite vein and silicic zone of the Seongsan deposit compared with that of minerals and rocks from another deposits distributed in the studied area. Gold content in tuffs and dickites with pyrite is generally low. Gold content in silicified tuff tends to show positive correlations with content of As, Hg and Sb. Variation trends of Cd, Hg and Sb are similar to those of gold content. From the result of gold content variations, gold may be transported and concentrated by mineralizing solutions ascending along the cracks like fault. Therefore, it is important to survey alunite vein and silicified zone at the conjunction of faults, and to analyze pathfinder elements such as As, Hg and Sb for geological and geochemical exploration of gold in the studied deposits.

• Journal of the speleological society of Korea
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• v.42 no.2
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• pp.33-40
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• 1995

The Cheonbo gold mine is located approximately 8km northeast of Cheonan in southern part of Korean peninsula. The Cheonbo gold deposits are composed of parallel-filling quartz veins that are associated wi th the Cheonan granite which intruded the surrounding Precombrian metamorphic country rocks. Rb/Sr date of the granitic intrusion is 170${\pm}$0. 3m.y., suggesting a middle Jurassic age for gold mineralization.

• Journal of the Speleological Society of Korea
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• v.34 no.35
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• pp.105-112
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• 1993

The Cheonbo gold mine is located approximately 8km northeast of Cheonan in southern part of Korean peninsula. The Cheonbo gold deposits are composed of parallel-filling quartz veins that are associated with the Cheonan granite which intruded the surrounding Precombrian metamorphic country rocks. Rb/sr date of the granitic intrusion is 170$\pm$0.3m.y., suggesting a middle Jurassic age for gold materialization.

• The Journal of the Petrological Society of Korea
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• v.17 no.1
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• pp.36-43
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• 2008

Many plutonic rock fragments of granitic composition were collected from the Deception Island. We obtained K-Ar ages of $62.5{\pm}1.2\;Ma$ and $140.7{\pm}2.7\;Ma$ from the two samples. Such result contradicts the general belief that most of the volcanic rocks of Deception Island are products of very recent activities and their maximum age does not exceed 200 ka. On the other hand, Mesozoic to Cenozoic rocks produced by subduction-related active magmatism have been reported from both South Shetland Islands and Antarctic Peninsula, located to the north and south of the Deception Island respectively. Also, various kinds of plutonic rocks with granitic composition are distributed widely. Therefore, plutonic rock fragments with granitic composition discovered from the Deception Island seem to indicate their derivation by capturing granitic crustal material underlying volcanic edifice during the volcanic activities, instead of differentiation from magmas related with recent volcanism. Ages and rock types of the plutonic rock fragments suggest arc-related origin just as adjacent South Shetland Islands and Antarctic Peninasula.

• The Journal of the Petrological Society of Korea
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• v.26 no.4
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• pp.385-398
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• 2017

Jiri Mountain lies in the southwestern portion of the Yeongnam massif, which is one of the Precambrian basement massifs of the Korean Peninsular, consisting essentially of high-grade metamorphic rocks. The geology of the area mainly consists of Paleoproterozoic metasedimentary migmatitic gneisses, granitic gneisses which are classified into granitic gneiss, (K-feldspar porphyroblastic) granitic gneiss and quartzo-feldspathic gneiss, charnockite and anorthosite based on their occurrence and petrographic characteristics. The ages obtained from these rocks mainly span a narrow range between ca. 1,876 and 1,856 Ma although inherited cores of zircons from massive granite gneiss yielded much older age spectrum (>2,029 Ma). The age of major metamorphism is ca. 1850-1840 Ma and the metamorphic condition obtained from mineral assemblages and geothermobarometers is about 4-6 kb and up to $700-750^{\circ}C$. These results indicate that in the area intense granitic magmatism and metamorphism occurred in the deep crust during Paleoproterozoic orogeny. Some younger age of charnockite (1,856-1,865 Ma) and anorthosite (1,861-1,862 Ma) might indicate the beginning of intraplate rifting leading to felsic and mafic magmatism just after the orogeny. In conclusion, the rocks in the Jiri Mountain area which formed at a mid to deep crustal zone provide us windows into the deep crust.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.13 no.2
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• pp.207-221
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• 2002

Wolaksan is a national park which has beautiful scenery with exposed rocks. The mountain is 1097 meters high and has 3 tops which are Jungang(the center), Arae(the lower part), Jjokduri. The highest point of the vertical cliff is 150m from the earth and the total circumferences of three tops is about 4km. These tops are easy to break by grains because they are from sedimentary rocks. Wolaksan is a bad mountain because the area is a Mosikjuk rocky area. However, the area around Wolaksan is thicky wooded and has many achievements and it makes good scenery. From top to southeastern, there are vertical cliff, The tops are originally from one but these are divided by partial weathering corrosion. The slide of path to Wolaksan is about 70。. The lower part of the mountain from Shinroksa to top has a gentle slope but there are a steep slope from the middle. Especially, the area has many rocks. The rocks of Wolaksan are almost granitic-gneiss or metamorphic rocks so it often fall down. Because of these fallen rocks, its valleys have great landscapes. The size of rock is less than 60cm. The landscapes of valleys such as Songgye, Dukju, Yonghwa are the main natural tourism resources.

• 보존과학연구
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• s.16
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• pp.123-128
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• 1995

For establishing the plan of scientific conservation on the Kyongch′onsa and site of Won-gaksa 10 floors pagodas, the investigation on the rocks consisting these pagodas has been made on the rock phase and weathering characteristics. The Kyongch′onsa pagoda consists of fine grained pale graylimestone containing abundant fossils of shell and fragments of organisms. The site of Won-gaksa pagoda is composed of marble of pale gray, white and/or light brown color, which is intercalated with thin mica schist. The marble, the recrystallized limestone, consists mainly of recrystallized calcite accompanied with minor amount of muscovite. Especially carbonate rocks are somewhat different in chemical weathering from such granitic rocks. The field survey and laboratory experiment using polarizing microscope had been done during 30 days from Feb, 13 to March, 31, 1995. The rocks equivalent to that of the site of Kyongch′onsa were identified from the Myobong limestone formation and taken samples around the road from P′yongch′ang to Mitan, P′yongch′ang-gun. The rocks similar to that of the site of Won-gaksa pagoda were distributed around Pan-un-ri, Chunch′on-myon, Yong-wol-gun. The rocks of the Silluksa pagoda consisting of white recrystallized limestone with banded structure are similar to the marble of the Hyangsan-riformation distributed around Suanbo, Ch′ungch′ongbuk-do.