• Korean Journal of Mineralogy and Petrology
• /
• v.34 no.4
• /
• pp.293-311
• /
• 2021

The volcanic rocks that make up Yeongdo island, an administrative district located on the southern coast of Busan, are composed of andesitic and rhyolitic rocks. Andesitic rock is mainly composed of volcanic breccia has a phenorysts of plagioclase and contains rock fragments. The rhyolitic rock is composed of volcanic angular rock at the base of Mt. Bongnae, and welded tuff forms the main mass of Mt. Bongnae. The fiamme structure can be easily observed with the naked eye, and the higher the altitude, the weaker the welded structure develops and the less the amount of rock fragments and crystals constituting the welded tuff. It is indicated that the magma that formed this study area is related to the tectonic environment of the continental margin related to subduction, and that it erupted after undergoing fractional cystallization at the same time with some contaminant in the continental crust. As a result of analyzing the main elements by altitude, it is believed to be the result of mixing at least 4 times or more of magma batches.

• The Journal of the Petrological Society of Korea
• /
• v.9 no.2
• /
• pp.84-98
• /
• 2000

Daejeon-sa basalt in the Mt. Juwang area composed of 12 basalt flows alternate with 9 peperites and each basalt and peperite has the variety of thickness. Peperites yielded in Daejeon-sa basalt are mixed of basalt with reddish shale, of which textural type is globular peperite. Basalts yielded in Daejeon-sa basalt are massive basalt without vesicule, although sometimes vesicules are founded in upper within a flow unit. The basalt has mainly pseudomorph of olivine as phenocryst, and also plagioclase and clinopyroxene phenocryst. Matrix is mainly subophitic texture. The plotting result on the TAS diagram shows these basalts belong to the sub-alkaline, and it can be subdivided into calc-alkaline series on the basis of the diagram of Si02 vs. K20 and of alkali index vs. A1203 diagram. According to plots of wt.% oxides vs. wt.% MgO, abundances of A1203 and CaO increase with decreasing MgO while F ~ dOecre~ase . With decreasing MgO compatible elements decrease while incompatible elements increase. In spider diagram of MORB-normalized trace element patterns, HFS elements are nearly similiar with MORB, but LIL elements are enriched. Especially, contents of Ce, F: and Sm are enriched but Nb is depleted. In the chondrite-normalized REE patterns light REEs are enriched than heavy REEs. Tectomagmatic discrimination diagrams shows basalts in the study area are formed in the tectonomagmatic environment of subduction zone under continental margin. This result accord with characters of chemical composition mentioned above. Cr vs. Y diagram and CeM, vs. Ce diagram show that the primary magma of the basalts may formed by the about 15% partial melting of garnet-peridotite in the mantle wedge. After then, Daejeon-sa basalts may formed from evolved magma undergone mainly olivine fractional crystallization and contarnination of crustal materials before eruption.

• (The) Research of the performance art and culture
• /
• no.34
• /
• pp.315-353
• /
• 2017

This study examined the music policies of the three kings, Seongjong, Jungjong, and Injo, who were in power for about 200 years from the late 15th century to the early 17th century. These three kings deserve attention in musical history for different reasons. Sungjong published "Gugjooryeui"(1474), "Gyeong-gugdaejeon"(1476), and "Aghaggwebeom"(1493), the typical etiquette books, law books, and musical books that take the most important position in the history of Joseon, so his direction of music policy deserves attention. Jungjong was the king who rose to the throne after there was a revolt against Yeonsangun's tyranny. Injo ascended to the throne by starting a military coup d'etat himself. One may wonder how the aspect of music policies developed by a king, who was crowned by a revolt, is different from other cases. As each of these three kings had different background of enthronement and the contents of music policies in the royal family also developed with different emphasis, this study examined each aspect separately. Sungjong emphasized the importance of music and regarded it important to cultivate officials who know music. To this end, he gave a special order to Yejo(the office of protocol) and this study tried to clarify the contents first. In addition, this study examined the process, contents, and meaning of various modification works related to the revision of the lyrics used in the ceremonies. Jungjong supplemented the institutional aspects of music. This is the result of expressing the will to correct the anomalous and reckless music policies of the period of Yeonsangun. In addition, many words in the lyrics had been about Buddhist doctrines and love songs between male and female, so there were efforts to reform these. As for the period of Injo, this study examined the music policies that were made in the process of resolving the crisis after the war. It was a time when court musicians were scattered after two times of war and it was not possible to hold the national ritual properly, so music policies in this period were different from the ones in stable era. This study covered discussions on the measures to collect lost instruments and scattered musicians. It also looked at how the restoration effort was made in the situation that the music used in ancestral rites was abolished.

• The Journal of Korean Philosophical History
• /
• no.32
• /
• pp.43-78
• /
• 2011

The two schools which eventually came to form the "Northerners party" in the middle period of the Joseon dynasty, were Nam'myeong school and Hwadam school. Nam'myeong's philosophy, which emphasized the importance and merit of acting upon respect and righteousness(敬義), encouraged many people to organize righteous militias during the war with the Japanese in the 1590s, and when Jeong In-hong established himself as the leader of the Northerners party during the reign of King Gwang'hae-gun, the philosophy of the party and the school continued to thrive. Also, Hwadam's philosophy, which tried to understand Neo-Confucianism from a flexible point of view and demonstrated a level of openness toward it, had a considerable influence upon the Northerners school as well. It seems Nam'myeong Jo Shik and Hwadam Seo Gyeong-deok were the ones who ultimately enabled the Northerners party to be more active in their operations of the government and also to approach more freely toward the ideology of Neo-Confucianism. Prime examples of the party's stance and attitude, and also of the school's philosophy and perception of the world, were figures like Jeong In-hong and Heo Gyun from the 'Majority Northerners(大北) party,' and Kim Shin-guk and Nam I-gong from the 'Minority Northerners(小北) party.'Since the time of King Injo's ascension to the throne in 1623, the philosophical society of Joseon came to be occupied by schools who were deeply committed and dedicated to the teachings of Ju Hi and his Neo-Confucianism, such as the Twe'gye and Yulgok schools, and as a result the Northerners' philosophy was pushed away from its former formidable status. Their political philosophy was also partially responsible for their fall, as they believed only them were the ideal Confucian figures(君子黨), and never appreciated the stances of other political factions. In the middle of the 17th century, passing through a war with the Manchurian Qing dynasty as well, they further became a mere undercurrent. Yet their thinking and philosophy partially survived, as it managed to affect and influence the Southerner school scholars who were living in the vicinity of the capital in the mid and late 17th century, as well as the "Shilhak" scholars such as Yi Ik/李瀷 in the 18th century, on a certain level. The Northerners faction was a party and a school which led the political and philosophical societies of Joseon, alongside the Westerners and Southerners, in the middle period of the Joseon dynasty. Recently, studies of Jo Shik and Seo Gyeong-deok, figures who were the roots of the Northerners faction, and studies of how the Northerners' political philosophy was inherited to the following generations, have been published and announced. All these efforts will enrich future studies dealing with the political history and philosophical history of the middle and latter periods of the Joseon dynasty.

• The Journal of the Petrological Society of Korea
• /
• v.24 no.4
• /
• pp.323-335
• /
• 2015

Although the Daljeon Basalt in the Pohang Basin is important for interpreting the basin evolution, its relative chronology, stratigraphic position, and isotopic age still remain controversial. In order to clear up the controversies, this study carried out detailed field investigation to determine its distribution and occurrence together with reanalysis of its previous geochemical data and $^{40}Ar/^{39}Ar$ age dating. Based upon the field investigation, the basalt occurring in the central part of the Pohang basin is composed of three main bodies and a dozen of minor dikes and sills that intruded into the Yeonil Group. Their mineral assemblages consist of phenocrysts such as olivine and clinopyroxene and fine groundmasses of clinopyroxene, plagioclase, olivine, and opaque oxide, impling the porphyritic texture of alkaline basalt. All their geochemical data also show the similar geochemical characteristics in TAS, Zr-Ti, and REE/trace elements distribution diagrams. The samples are plotted on alkalic field in the total alkali-versus-silica diagram and show similar patterns to enrichment oceanic basalt or within plate basalt in trace elements. In addition, $^{40}Ar/^{39}Ar$ isochron age of 13.82Ma is obtained. These results indicate that the Daljeon Basalt is an alkaline intrusive rock belonging to the middle Miocene Yeonil Group.

• Journal of the Korean earth science society
• /
• v.28 no.3
• /
• pp.324-342
• /
• 2007

This study reports petrography and geochemical characteristics of the basalt lava flows in Seongsan-Ilchulbong area, the easternpart of Jeju island, Korea, to understand the evolutionary processes of magma. Basalt lavas are classified into the Pyoseon-ri basalt and the Seongsan-ri basalt. The Pyoseon-ri basalt is dark-gray colored with many vescicles, and mainly consists of olivine, feldspar and rarely of clinopyroxene as phenocrysts. The Seongsan-ri basalt is largely aphanitic basalt and bright-gray colored, divided into two lava-flow units: lower lava flow (B1) and upper lava flow (B2) by the intercalated yellowish lapillistone and paleosol. The lavas plotted into sub-alkaline tholeiitic basalt and alkaline basalt series. The tholeiitic basalts have characteristically higher $SiO_2,\;FeO^T$, and CaO contents, but lower $TiO_2,\;K_2O,\;P_2O_5$ and other incompatible elements compared to the alkali basalts. The tholeiitic basalts have higher $SiO_2$ to the same MgO contents than the alkalic basalts. The contents of Ni, Cr, and MgO show a strong positive correlation, which indicates that low-MgO phases like plagioclase and titanomagnetite were important during the differentiation of magma. The contents of incompatible elements against that of Th show a strong positive correlation. The chondrite-nomalized REE patterns of tholeiitic and alkalic basalts are subparallel each other. LREEs contents of the former are lower than, but HREEs contents are similar to the latter. They both are similar to their K/Ba ratios. The primitive-mantle normalized spider diagram demonstrates that the contents of Ba and Th of all basaltic magma are enriched, and yet Cr, Ni are depleted. The tholeiitic and alkalic basalts may be originated from a different degree of the partial melting of the same mantle material source, and one shows a higher degree of the partial melting than the other.

• The Journal of the Petrological Society of Korea
• /
• v.9 no.3
• /
• pp.169-186
• /
• 2000

The Miocene volcanic rocks in the Dangsari area, eastern part of Ulsan city, are mainly composed of andesite lava flows and pyroclastic rocks. The andesite lavas are identified as two-pyroxone andesite, comprising phenocrysts of augite ($Wo_{43.2}$ $En_{41.0}$ $Fs_{15.8}$ ) and hyperthene ($Wo_{2.7}$ $65.8_{En}$ $_{Fs}$ 31.5). The andesitic pyroclastic rocks are largely composed of pyroclastic breccias with alternating tuff-breccia and lapilli tuff, which showing planar layering, and minor amount of andesitic tuff with thin deposits of interlayered tuffaceous shale. According to the petrochemical data, andesitic rocks belong to medium-K calc-alkaline andesite. The position of bulk composition on the AFM diagram and the presence of normative quartz and hypersthene indicate that the volcanic rocks are calc-alkaline. The trace element composition and REE patterns of andesite, which are characterized by a high LILE/HFSE ratio and enrichment in LREE, suggest that they are typical of continental margin arc calc-alkalic volcanic rocks produced in the subduction environment. On the discrimination diagram, the Dangsari volcanic rocks fall into the fields of subduction related continental margin arc volcanic province. The primary magic melts may be derived from about 15% partial melting of mantle wedge in the upper mantle under destructive plate margin. And the melt evolved to calc-alkaline andesite magma by fractional crystallization and the magma was a little contaminated with crustal materials.

• The Journal of the Petrological Society of Korea
• /
• v.9 no.3
• /
• pp.142-168
• /
• 2000

The granites distributed in the Kyongsang basin contain the rocks which are different from the host rocks, and they are known as magic microgranular enclaves. The genesis of the magic micro-granular enclaves can be divided into four types: (1) rock fragments from country rocks; (2) cumulation of the early crystals in host magma or disruption of early chilled borders; (3) magma mingling; and (4) restite. These enclaves can be easily found in the granites around Mt. Wonhyo, Yangsan city. They are ellipsoidal in shape, and have phenocrysts might be originated from the host rocks and sharp contacts with the granites. Under the microscope, textures such as oscillation zoning, horn-blende-mantled quartz, rapakivi texture, and acicular apatite are observed, and these indicate that the enclaves were originated from magma and then produced by chilling. The evidences showing that the enclaves were formed by magma mingling are: (1) petrographical characteristics; (2) similarity of the compositions between the rim of plagioclase in the enclave and plagioclase in the granite; (3) linear trends of the major elements; (4) total REE content of the enclaves; and (5) Textural and compositional variations from rim to core in zoned enclaves. The magic end member of the enclave is regarded as the aphyric basaltic andesite in Mt. Sinbul-Youngchui area. The granites around Mt. Wonhyo experienced the magma mingling process which was produced by the injection of mafic magma at about 70 Ma, during the crystal differentiation, and then continued the crystallization. The equigranular granites and the micrographic granites in the study area are considered as the results after the magma mingling process.

• The Journal of the Petrological Society of Korea
• /
• v.13 no.3
• /
• pp.161-177
• /
• 2004

The Cretaceous pink granites of the finan area, southwestern Ogcheon belt, are adjacently developed in the eastern part (Keg) and western part (Kwg) as stocks, respectively. Keg of rounded shape occur as mainly medium-coarse grained rocks, whereas Kwg of ellipsoidal shape occurs as medium-coarse grained ones with partly porphyritic and fine-grained textures. Miarolitic cavities of them are often seen and can be observed more frequently in Kwg than Keg. Rose and counter fracture diagrams of the two granites show that Keg and Kwg have more potentiality of non-dimension and dimension to non-dimension stones, respectively. Physical properties such as porosity and absorption ratio have 0.25% and 0.65％, and 0.43% and 1.11%, respectively, which could suggest that emissions of gas phase at later magma stages are abundant in Kwg than those of Keg. From the major and trace elements petrochemisoy, they belong to acidic, peraluminous and calc-alkaline rocks, showing that Kwg are later product than Keg of the same granitic parent magma. REE concentrations normalized to chondrite value have trends of gradual and parallel enriched LREE and depleted HREE. Eu negative anomalies of Kwg are far more severe than those of Keg, which suggest that plagioclase fractionation in Kwg was much stronger than that of Keg. In the magnetic susceptibility vs. petrochemical and modal parameters, they all belong to magnetite-series and I-types, and can be classified as weakly-moderately ferromagnetic rocks. And the above relations could suggest that their susceptibility values are more mainly depended on ferromagnetic opaques than ferromagnetic and paramagnetic assemblages (Bt ＋ Ch ＋ Ser ＋ Op).

• Journal of the Mineralogical Society of Korea
• /
• v.18 no.4 s.46
• /
• pp.313-323
• /
• 2005

XRD, XRF, EPMA, FT-IR, and SEM-CL studies were carried out in order to characterize gemological features of corundum from Tanzania. Fluorescence reaction of the Tanzanian corundum to short and long wave ultraviolet rays was weakly detected. Inclusions in Tanzanian corundum are divided into five types, Type I is fluid-rich inclusion, Type II is gas-rich inclusion, Type III is liquid $CO_{2}$ inclusion, Type IV is solid-rich inclusion, and Type V is a mixture of fluid and solid inclusion and daughter minerals. SEM-CL images show twin structure with growth texture, microphenocryst of spinel solid inclusions, massive and growth texture. Ruby and sapphire from Tanzania are distinctly distinguished by concentrations of Fe and Cr, and plotted in the particular field at $Al_{2}O_{3}/100-Cr_{2}O_{3}-Fe_{2}O_{3}$ diagram. According to FT-IR analysis, all corundum specimens from Tanzania showed the similar patterns, and absorption peaks of $455.09\~459.23\;cm^{-1},\;603.15\~611.71\;cm^{-1},\;1509.00\~1655.05\;cm^{-1}\;and\;3436.41\~3468.87\;cm^{-1}$. These distinctive characteristics mentioned above can be used to identify the locality and source of corundum stones from Tanzania.