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The major and trace elements of Quaternary alkaline volcanic rocks on Jeju Island were analyzed to determine their origin and formation mechanism. The samples included tephrite, trachybasalts, basaltic trachyandesites, tephriphonolites, trachytes, and mantle xenoliths in the host basalt. Although the samples exhibited diversity in SiO2 contents, the relations of Zr vs. Nb and La vs. Nb indicated that the rocks were formed from the fractional crystallization of a single parent magma with slight continental crustal contamination (r: 0–0.3 by AFC modeling), rather than by the mixing of different magma sources. The volcanic rocks had an enriched-mantle-2-like ocean island basalt signature and the basalt was formed by partial melting of the upper mantle, represented by the xenolith samples of our study. The upper mantle of Jeju was affected by arc magmatism, associated with the subduction of the Pacific Plate beneath the Eurasian Plate. Therefore, we inferred that two separate magmatic events occurred on Jeju Island: one associated with the subduction of the Pacific Plate beneath the Eurasian Plate (represented by xenoliths), and another associated with a divergent setting when intraplate magmatism occurred (represented by the host rocks). With AFC modeling, it can be proposed that the Jeju volcanic rocks were formed by the fractional crystallization of the upper mantle combined with assimilation of the continental crust. The xenoliths in this study had different geochemical patterns from previously reported xenoliths, warranting further investigations.
Cheolhong Kim; Naing Khant; Yongmun Jeon; Heejung Kim; ChungWan Lim. Geochemical Characterization of Intraplate Magmatism from Quaternary Alkaline Volcanic Rocks on Jeju Island, South Korea. Applied Sciences 2021, 11, 7030 .
AMA StyleCheolhong Kim, Naing Khant, Yongmun Jeon, Heejung Kim, ChungWan Lim. Geochemical Characterization of Intraplate Magmatism from Quaternary Alkaline Volcanic Rocks on Jeju Island, South Korea. Applied Sciences. 2021; 11 (15):7030.
Chicago/Turabian StyleCheolhong Kim; Naing Khant; Yongmun Jeon; Heejung Kim; ChungWan Lim. 2021. "Geochemical Characterization of Intraplate Magmatism from Quaternary Alkaline Volcanic Rocks on Jeju Island, South Korea." Applied Sciences 11, no. 15: 7030.
Climate-related changes that have occurred over the last few decades are particularly induced
Heejung Kim; ChungWan Lim. Strategies to Assure the Sustainability of Groundwater Resources. Sustainability 2020, 12, 9183 .
AMA StyleHeejung Kim, ChungWan Lim. Strategies to Assure the Sustainability of Groundwater Resources. Sustainability. 2020; 12 (21):9183.
Chicago/Turabian StyleHeejung Kim; ChungWan Lim. 2020. "Strategies to Assure the Sustainability of Groundwater Resources." Sustainability 12, no. 21: 9183.
Myanmar is endowed with a diverse array of metallic and nonmetallic mineral deposits, a number of which have recently been developed as world-class mines. Tagaung Taung deposit north of Mandalay is a resource approximately 40 km from Mandalay City. The Phayaung Taung gold deposit from the Slate Belt is hosted in phyllite, schist, and quartzite. Mineralization is associated with the stockwork quartz vein system. Wall-rock silicic alteration by cryptocrystalline quartz or amorphous silica is dominant. Phyllic alteration is characterized by sericite, quartz, chlorite, and pyrite with disseminated hematite. Gold occurs in tourmaline-quartz and sulfide-bearing quartz veins. It is associated with pyrite and chalcopyrite as well as Au-Ag-Bi-Te ore assemblages of petzite, hessite, and tellurobismuth. The Phayaung Taung gold deposit shows typical mesothermal characteristics. Scanning electron microscopy with energy-dispersive X-ray analyses revealed the average gold content of electrum grains, i.e., 75.1 wt% Au, with grain sizes ranging from 3 to 40 µm. Moreover, secondary native gold grains were formed with hematite and iron oxides in secondary remobilized/deformed veins at strongly brecciated/oxidized zones. The association between gold and altered sulfides suggests that gold was refractory in sulfides. It can be considered that supergene oxidation extended to deep mineralization veins. Such gold grains had the highest Au content, and are often in almost pure condition. This study discussed the geology, geochemistry, and mineralogy of the Phayaung Taung gold mine in Myanmar. New minerals were identified in the samples obtained from the study area, which were subjected to multiple analyses to determine their properties and understand the relationships between them.
Naing Aung Khant; Adam Piestrzynski; ChungWan Lim. Geology, geochemistry, mineralogy of Phayaung Taung, Patheingyi Township, Mandalay Division, Myanmar. Geosciences Journal 2020, 25, 145 -156.
AMA StyleNaing Aung Khant, Adam Piestrzynski, ChungWan Lim. Geology, geochemistry, mineralogy of Phayaung Taung, Patheingyi Township, Mandalay Division, Myanmar. Geosciences Journal. 2020; 25 (2):145-156.
Chicago/Turabian StyleNaing Aung Khant; Adam Piestrzynski; ChungWan Lim. 2020. "Geology, geochemistry, mineralogy of Phayaung Taung, Patheingyi Township, Mandalay Division, Myanmar." Geosciences Journal 25, no. 2: 145-156.
Carbon isotope thermometry between calcite and graphite has been applied to Precambrian granulite facies marbles in the Northeast Yeongnam massif, Gyeongbuk Province Korea. 11 pairs of calcite-graphite samples indicate the peak metamorphic temperature of 752 53 °C which well matches with the temperature estimated with a petrological study by other researchers. Graphite from this study mainly shows highly lustrous coarse grains and fine crystalline graphite crystals on coarse grains. Thus it well presents the peak metamorphic temperature. Fine graphite crystals on coarse graphite grains are possibly originated from the later stage overgrowth but their high lustrousness may represent prograde metamorphism after formation, which is related to later igneous activity which is related to the Jurassic granite intrusion and near the granite the highest temperature, 835 °C, was obtained. With almost no shift in δ13C and only locally shifted δ18O in the calcite samples of the study area, CO2-depleted fluid may have affected the marble at the last stage of metamorphism by the Jurassic granite intrusion. The δ13C and δ18O values of the calcite in the study area show relatively higher values than other Precambrian calcite. It would be interesting to compare the C–O isotope values with those from the Cathaysia Craton of the South China Block which is believed to be correlated to Yeongnam massif.
Cheolhong Kim; Heejung Kim; ChungWan Lim. Carbon-oxygen isotope records of Precambrian metamorphic rocks in the Yeongnam massif area, South Korea. Precambrian Research 2020, 346, 105739 .
AMA StyleCheolhong Kim, Heejung Kim, ChungWan Lim. Carbon-oxygen isotope records of Precambrian metamorphic rocks in the Yeongnam massif area, South Korea. Precambrian Research. 2020; 346 ():105739.
Chicago/Turabian StyleCheolhong Kim; Heejung Kim; ChungWan Lim. 2020. "Carbon-oxygen isotope records of Precambrian metamorphic rocks in the Yeongnam massif area, South Korea." Precambrian Research 346, no. : 105739.