• Journal of the Korean earth science society
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• v.25 no.4
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• pp.222-231
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• 2004

The purpose of this study is to analyze the seventh curriculum textbooks and teacher's guides of high school science courses in relation to the generation (mechanism) of magma in subduction boundary and find the incorrect descriptions of the texts and the figures (illustrations) and then suggest some improved schemes. According to the result there are many discrepancies in definition of 'magma' among the textbooks and further little scientific explanations about the formation mechanism of magma in most textbooks, and even no descriptions about that. In addition, the figures are inconsistent with the description of the text and also have some incorrect depiction which might contribute to the forming and reinforcing misconceptions about Plate Tectonics as well as a volcanic activity in subduction boundary. On the basis of the previous researches, therefore, some improved schemes (text descriptions and figures) are suggested. The results of this study should be used as a reference for publishing science textbook, developing science curriculum, and teaching effectively in the high school.

• The Journal of the Petrological Society of Korea
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• v.16 no.4
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• pp.196-207
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• 2007

Miocene basalt plugs in Goseong contain a large variety of crustal and mantle xenoliths and xenocrysts. One of basalt plugs, Unbongsan, are derived from 160 km depth. Whole-rock geochemistry and pressure and temperature conditions of mineral phases indicate that Unbongsan volcanic rocks are alkali basalts and the source magma of the alkali basalts was generated from about $0.2{\sim}2%$ partial melting of depleted garnet peridotite. Crystallization pressures and temperatures of mineral phases within ascending magma of Unbongsan alkali basalt indicate that olivines, clinopyroxenes, and plagioclases were crystallized at $75{\sim}110km,\;40{\sim}52km,\;37{\sim}54km$ depth, respectively. The ascending magma of Unbongsan alkali basalts enclosed mantle xenoliths at about $57{\sim}67km$ depth.

• The Journal of the Petrological Society of Korea
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• v.10 no.1
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• pp.13-26
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• 2001

Songaksan volcano, which occurs as a monogenetic volcano on the southwestern promontory of Hallasan shield volcano, is composed of tuff ring, cinder cone, lava pond and cinder conelet complex on wide basalt plateau. Except for an influx of external quartz xenocrysts in the tuff ring. Totally the volcano ranges from trachyandesite to trachybasalt in petrography and chemical compositions, which confirm the continuum between the evolved and primitive compositions widely occurring in the Jeju volcanic system. Chemical data for the volcano show quantitative compositional variation from the lower to the upper part of the volcanic sequences. The continuous compositional variations generally define a compositionally zoned magma storage. The chemical data suggest that the compositiona1 donations might have resulted from the fractional crystallization of a parental alkali magma. As result, the Songaksan volcano initially tapped the lop of the zoned magma storage and subsequently erupted successively more primitive magma.

• Korean journal of food and cookery science
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• v.33 no.3
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• pp.292-299
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• 2017

Purpose: The present study explored cookie making performance using Jeju magma seawater to elucidate the effects of minerals in water on quality of baked goods. Methods: Seven water samples were analyzed for their mineral content, pH and water hardness. Starch pasting properties of flour in water samples was analyzed using RVA, and cookie making performance using water samples was evaluated with the AACCI wire-cut cookie baking method. Quality of cookies was measured by weight loss during baking, cookie geometry, color, and firmness. Results: Hardness of water samples ranged from 0-4200, and mineral content was in the order of magma seawater > 100% ED mineral water > 50% ED mineral water > 10% ED mineral water > tap water > Samdasoo > distilled water. RVA results showed that water hardness exhibited significant relationships with pasting temperature (p<0.05, R=0.863), peak viscosity (p<0.001, R=0.944), final viscosity (p<0.05, R=0.861), and setback (p<0.05, R=0.782). Cookie baking results showed that cookie diameter increased in the order of magma seawater < 100% ED mineral water < 50% ED mineral water < 10% ED mineral water $\approx$ tap water < Samdasoo < distilled water. Conclusion: As mineral content in water increased, flour pasting temperature and viscosity increased, whereas cookie diameter decreased with color fading. However, cookies formulated with 50% ED mineral water showed similar cookie geometry and texture to those with tap water. Therefore, controlling the mineral content of water can be successfully applied to produce mineral-enriched cookies.

• Economic and Environmental Geology
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• v.21 no.4
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• pp.381-387
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• 1988

Maewol Feldspar Mine produces feldspar ore from pegmatites. K-Rb Age of muscovite is 137.7Ma. Fluid inclusions in quartz crystal of the pegmatite show bimodal distribution of homogenization temperatures. The high homogenization temperatures range from 290 to $302^{\circ}C$ while low homogenization temperatures range from 157 to $195^{\circ}C$. Three phases liquid $CO_2$ bearing inclusions indicate $CO_2$ gases were abundantly mixed with granitic melt until the pegmatic magma melt cooled to $290^{\circ}C$. Low density of the magmatic melt relative to the same volume of granitic magma is due to mixture of volatiles(mainly $CO_2$ gases) with the melt and larger space and slow cooling allowed to grow crystals of the pegmatic magma.

• The Journal of the Petrological Society of Korea
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• v.14 no.1
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• pp.12-23
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• 2005

Cretaceous granitic rocks in the Waryongsan area occur as a stock and show compositional changes with altitude. They include mafic microgranular enclaves (MME) with various sizes and types. The MMEs present clear evidence of magma mingling such as supercooling zone, mantling texture and back veining. The granitic rocks are divided into porphyritic granite, porphyritic granodiorite and fined-grained granite by their petrographic characteristics and modal compositions. The MMEs are discriminated to quartzdioritie, quartzmonzodiorite and tonalite. They have varying areal proportions in each granitic rock-type: 10∼l5% in the porphyritic granite, about 50% in the porphyritic granodiorite, and about 20% in the fined-grained granite. SiO₂ contents shows compositional change of 61.2∼72.0wt.%. Mean SiO₂ contents have 61.7wt.% in the porphyritic granodiorite, 68.6wt.% in the porphyritic granite. and 71.9wt.% in the fined-grained granite, respectively. Major oxide contents of the granitic rocks linearly vary with SiO₂ contents from the porphyiritic granodiorite to the fine-grained granite on Harker diagrams. Linear compositional variations seem to have been caused by differential degrees of mingling between mafic magma and host granite. Where larger amount of mafic magma was injected into the host granitic magma, the two magmas reached to thermal equilibrium more quickly and eventually chemical mixing occurred to produce the composition of the porphyritic granodiorite. On the other hand. less amount of injected mafic magma would have been responsible for mechanical mixing to produce the compositions of the porphyritic granite and the fined-grained granite. Therefore, it is considered that the granitic rocks in the Waryongsan area experienced magmas mingling resulting from the injection of more mafic magma into differentiating granitic magma, and that the compositional changes of the granitic rocks were ascribed to the degree of mingling between the two magmas.

• Journal of the Mineralogical Society of Korea
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• v.28 no.1
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• pp.61-69
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• 2015

While the macroscopic properties and eruption style of basaltic and phonolitic melts are different, the microscopic origins including atomic structures are not well understood. Here we report the atomic structure differences of glass in diopside-anorthite eutectic composition (basaltic glass) and phonolitic glass using high-resolution 1D and 2D solid-state Nuclear Magnetic Resonance (NMR). The $^{27}Al$ MAS NMR spectra for basaltic glass and phonolitic glass show that the full width at half maximum (FWHM) of Al for basaltic glass is about twice than phonolitic glass, suggesting the topological disorder of basaltic magma is larger than that of phonolitic magma. The $^{27}Al$ 3QMAS NMR spectra for basaltic glass and phonolite glass show much improved resolution than the 1D MAS NMR, resolving Al and Al. Approximately 3.3% of Al is observed for basaltic glass, demonstrating the configurational disorder of basaltic magma is larger than phonolitic magma. This result confirms that the topological disorder of Al in basaltic glass is larger than that of phonolitic glass. The observed structural differences between basaltic glass and phonolitic glass can provide an atomistic origin for change of the macroscopic properties with composition including viscosity.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.470-478
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• 2013

There have been a number of observed precursors of volcanic activities- such as volcanic earthquake, surface inflation, specific volcanic gas emission, temperature of hot spring- at Mt. Baekdusan since 2002. We identified the increase of the volume of magma chamber beneath Mt. Baekdusan as we observed an inflation trend of vertical and horizontal surface displacement around Cheonji caldera lake by using precise leveling data from 2002 to 2009. The surface displacement trend changed to deflation in 2010, and the trend changed to inflation again after a while. Utilizing the data of inflated surface (46.33 mm) on the northern slope of Mt. Baekdusan from 2002 to 2003, we calculated the volume change of magma chamber beneath the Mt. Baekdusan. The volume change was about 0.008 $km^3$ ($7.7-8.0{\times}10^6m^3$) from 2002 to 2003. It indicated that a new magma (0.008 $km^3$) injected to the magma chamber 5 km below Mt. Baekdusan.

• The Journal of the Petrological Society of Korea
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• v.11 no.1
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• pp.30-48
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• 2002

Phenocrysts with rapakivi texture are easily observed in Bangeojin granite. The rapakivi texture is composed of inner pinkish alkali feldspars and white-colored mantling plagioclase. The Bangeojin granite distinctively includes lots of mafic microgranular enclaves and can be divided into five rock facies: (1) enclave-poor granite (EPG); (2) enclave-rich granite (ERG); (3) mafic microgranular enclave (MME); (4) hybrid zone between mafic microgranular enclave and granite (HZ); (5) hybrid zone-like enclaves (HLE). The rapakivi textures are observed in these five rock facies with no difference in shape and size. Plagioclase mantle commonly shows dendritic texture that is an important indicator to know the rapakivi genesis. The mantling texture would indicate supercooling condition during magma solidification process. In addition, mafic microgranular enclaves would imply the magma mingling environment. The magma mixing process had possibly caused the mantling texture. An abundance of rapakivi phenocrysts in HZ and the influxing phenomenon of the phenocrysts into MME support that there were physical chemical exchanges during the mingling. And this model of the magma mixing/mingling explain well the heterogeneous distribution of the rapakivi phenocrysts in the five rock facies. Therefore the rapakivi textures in the Bangeojin granite would have been formed by magma mixing process.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.127-129
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• 2007

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