• Economic and Environmental Geology
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• v.26 no.4
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• pp.473-487
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• 1993

The Janggun mine area is occupied by the Proterzoic and the Paleozoic meta-pelites, which are intruded by the Jurassic Chunyang granite. The metamorphic terrain is divided into four zones of progressive metamorphism on the basis of mineral assemblages. The zones are chlorite zone, staurolite zone, andalusite zone, sillimanite zone ascending order. Boundary lines between the zones resemble outline of the Chunyang granite mass. Isograd reactions are chlorite+chloritoid+muscovite=staurolite+biotite+quartz+water, staurolite+chlorite+muscovite+quartz=andalusite+biotite+water, and staurolite+muscovite+quartz=andalusite+biotite+garnet+water between the chlorite zone and the staurolite zone, the staurolite zone and the andalusite zone, and the andalusite zone and the sillimanite zone, repectively. They are univariant reactions in KFMASH component system. Metamorphic conditions estimated from garnet-biotite geothermometers and phase equlibria are $530^{\circ}C$ and lower than 4 kb.

• Journal of the Mineralogical Society of Korea
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• v.15 no.2
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• pp.122-131
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• 2002

Muscovite, chlorite and biotite in metapelites of the Ogcheon Hetamorphic Belt are studied using electron probe microanalysis (EPMA), backscattered electron images (BEI) of scanning electron microscopy (SEM) and lattice fringe images of transmission electron microscopy (TEM). These minerals are observed to be intergrown under a polarized light microscope and are apparently interlayered below EPMA resolution; EPMA data often indicate mixtures of phyllosilicates such as muscovite/chlorite (M/C), biotite/chlorite (B/C), muscovite/pyrophyllite/chlorite (M/P/C). biotite/pyrophyllite/chlorite (B/P/C) or biotite/muscovite/chlorite (B/M/C). BEI observations show that the three minerals (muscovite, chlorite and biotite) are mixed at various scales in a grain through the garnet zone, and the interlayering of the three minerals are observed from TEM lattice fringe images and selected area electron diffraction patterns. The result of TEM observations reveals that 7-$\AA$ layers (serpentine, precursor of chlorite) are interlayered within 10-$\AA$ layers (muscovite) at 100~200 $\AA$ scale as well as M/C in the chlorite zone. The 7-$\AA$ layers become smaller in size and less frequent in the biotite tone, and 10-$\AA$ layers are interlayered with chlorite (14 $\AA$) at an individual layer scale. The 7-$\AA$ layers are no longer observed in the garnet zone, and 10-$\AA$ layers (biotite) are interlayered with chlorite (B/C) at 50~100 $\AA$ scale. Relatively large scale (1000~2000 $\AA$) of intergrowth is also frequently observed from the garnet zone samples. However, rocks from all three metamorphic zones show interlayering of a few units of 7-, 10- and 14-$\AA$ layers with each other at TEM observations. The result of this study implies that metamorphic minerals such as muscovite, chlorite and biotite form through disequilibrum mineral reactions resulting in inhomogenious phases.

• Journal of the Mineralogical Society of Korea
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• v.25 no.3
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• pp.143-153
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• 2012

Mica-type minerals (illites) in the shales of the Jigunsan formation at Seokgaejae in Samchuk-City, Gangwon-do are studied using electron probe micro analysis (EPMA). The average chemical formula of the mica-type mineral obtained from the quantitative analysis is $(K_{1.17}Na_{0.04}Ca_{0.01})(Al_{2.80}Mg_{1.17}Fe_{0.78})(Si_{6.34}Al_{1.66})O_{20}(OH)_4$, which shows a chemical formula within the range of illite. These illites so called can be considered as mixed-phases among muscovite, pyrophyllite and chlorite due to the low contents of interlayer cations and high Mg, Fe. The formula of illite is separated into those three minerals and the method for the separation is newly formulated and proposed in this study. From the formula of illite, the content of muscovite is estimated from K (Na and Ca included), the content of chlorite by Mg+Fe, and the rest remains as pyrophyllite. The chemical formula of muscovite can be calculated by subtracting the compositions of pyrophyllite and chlorite from the analyzed composition of illite using an ideal formula for pyrophyllite and analyzed average formula for chlorite. The calculated formula of muscovite is supposed to be stoichiometric in principle. The result of the separation of analyzed illite is 61% muscovite, 27.3% chlorite and 11.7% pyrophyllite and the calculated formula of muscovite after separation is $(K,Na,Ca)_{2.00}Al_{3.69}(Si_{6.75}Al_{1.25})O_{20}(OH)_4$. The calculated formula of muscovite slightly low in Al content can be considered to be reasonable in general when the low content of Al in the rock and the uncertainties of chlorite compositions used in the calculation are counted. This supports that the method of separation proposed in this study is also applicable.

• The Journal of the Petrological Society of Korea
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• v.6 no.3
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• pp.226-243
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• 1997

The Odesan Gneiss Complex consists of mainly migmatitic gneiss and porphyroblastic gneiss with locally intercated quartzite, amphibolite, marble and leucocratic gneiss. At least two different regional metamorphisms are recognized in the study area. Metamorphic grade of the first metamorphism increases from the K-feldspar-muscovite zone(in which biotite-muscovite-plagioclase-quartz and garnet-biotite-muscovite-K-feldspar-plagioclase-quartz assemblages occur) in the east and southwestern part of the study area to the K-feldspar-garnet zone(in which garnet-biotite-K-feldspar-plagioclase-quartz, biotite-K-feldspar-plagioclase-quartz, garnet-biotite-K-feldspar-plagioclase-sillimanite-spinel-quartz assemblages occur) in the northwestern part. Kyanite is found as inclusions in plagioclase. The second metamorphism is characterised by occurrence of cordierite. The metamorphic grade of 2nd metamorphism decreases radically from the central-western part near Gaeinsan in which cordierite-garnet-sillimanite-biotite-muscovite-quartz, cordierite-garnet-spinel-sillimanite-biotite-muscovite-quartz assemblages representing the garnet-cordierite zone are observed. The garnet-cordierite zone is surrounded by the sillimanite-cordierite zone which shows cordierite-sillimanite-biotite-plagioclase, cordierite-muscovite-biotite-plagioclase and sillimanite-muscovite-biotite-plagioclase assemblages. The peak metamorphic P-T conditions of the first metamorphism calcuted from garnet-biotite-sillimanite-K-feldspar-plagioclase-spinel assemblage are 5.4~7.4 kb and $776-789^{\circ}C$. Real P-T condition of the first metamorphism might be higher than the calcuated P-T condition according to the study based on the phase equilibria. P-T conditions calcuated from the garnet-biotite in plagioclase are 12.5kb and $650^{\circ}C$ which indicate that the P-T path of the first metamorphism had passed a high pressure condition before the peak metamorphic temperature condition. The peak metamorphic P-T conditions of the second metamorphism calcuated from garnet-biotite-cordierite-spinel-quartz assemblage are $680~750^{\circ}C$ at pressures lower than 6 kb. In the Odesan Gneiss Complex, the first metamorphism of medium pressure and high temperature had occurred after the high pressure condition and fast uplift and then the second metamorphism of low pressure condition occurred after sedimentation of the Kuryong Group.

• Economic and Environmental Geology
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• v.28 no.1
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• pp.33-41
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• 1995

Tin mineralizations in South Korea have been found only in the Ulchin and the Sangdong areas. The Wangpiri and the Yuchang Sn pegmatites appear to be in close spatial and genetical relation to the Wangpiri granitoid in the Ulchin area, and the Soonkyeong Sn pegmatite be in close association with the Nonggeori granites in the Sangdong area from geochemical viewpoint. The electron-microprobe analysis of muscovite, biotite, tourmaline and cassiterite from the granitoids and pegmatites in the Ulchin and the Sangdong areas has revealed a distinct differences of geochemical compositions. The Wangpiri and the Yuchang Sn pegmatites show an enrichment of MnO and a depletion of $TiO_2$, FeO and MgO in comparison with the Soonkyeong Sn pegmatite. This result coincides with the geochemical compositions of granitoid rocks in these areas. Enrichment of MnO and depletion of $TiO_2$ FeO and MgO are characteristic in muscovite, biotite and tourmaline of pegmatites compared with those of granitoids. These geochemical differences of muscovite, biotite and tourmaline between granitoids and pegmatites in these areas implies that pegmatites are more fractionated than granitoids.

• Economic and Environmental Geology
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• v.21 no.3
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• pp.209-221
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• 1988

The ore deposit of the Ohtani mine is one of repesentatives of plutonic tungsten-tin veins related genetically to acidic magmatism of Late Cretaceous in the Inner zone of Southwest Japan. Based on macrostructures of vein filling on the order of ore body, three major mineralization stages, called stage I, stage II, and stage ill from earliest to latest, are distinguished by major tectonic breaks. The alteration zories are characterized by specific mineral associations in pseudomorphs after biotite. The alteration zones can be divided into two parts, i. e. a chlorite zone and a muscovite zone, each repesenting mineralogical and chemical changes produced by the hydrothermal alteration. The chloritic alteration took place at the beginning of mineralization, and muscovite alteration in additions to chloritic alteration took place at stage II and ill. The alteration zones are considered to be formed by either of two alteration mechanism. 1) The zones are formed by reaction of the rock with successive flows of solution of different composition and different stage. 2) The zones are formed contemporaneously as the solution move outward. Reaction between the solution and the wall-rock results in a continuous change in solution chemistry. The migration of the successive replacement of the fresh zone$\rightarrow$the chlorite zone$\rightarrow$the muscovite zone may have transgressed slowly veinward, leaving metasomatic borders between the different zones.

• The Journal of the Petrological Society of Korea
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• v.3 no.1
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• pp.76-93
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• 1994

The Precambrian Hongjesa granite is lithologically zoned from biotite granite in central part to biotite-muscovite granite towards the margin. The X_{Fe}$ (=Fe/(Fe+Mg)) value and the aluminum saturation index of biotite systematically vary as a function of mineral assemblage, and are positively related with those of bulk rock. This relationship as well as the lithological zoning are attributed to the fractional crystallization of the Hongjesa granitic magma. The trace element data corroborate that biotite-muscovite granite is more fractionated than biotite granite. The evolution of the Hongjesa granite is elucidated by using the AFM liquidus topology, where A=$Al_2O_3-CaO-Na_2O-K_2O$; F=FeO+MnO; and M=MgO. At an early magmatic stage where biotite is the only ferromagnesian mineral to crystallize, the X_{Fe}$ value and the alumina content of granitic magma continuously increase.. Muscovite subsequently crystallizes with biotite along the biotitemuscovite cotectic curve where biotite-muscovite granite forms. Local enrichments in Mn and B further crystallize garnet and tourmaline, respectively. The unique zonal pattern characterized by the occurrence of the evolved biotite-muscovite granite at the margin may be accounted for by the passive stoping during the emplacement of the Hongjesa granite. This emplacement may have occurred in continental collision environment, according to the tectonic discrimination diagram using major element chemistry.

• Journal of the Mineralogical Society of Korea
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• v.26 no.1
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• pp.55-64
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• 2013

The generation of staurolite from the mixed-phase muscovite and the metamorphic environment of shales in the Baekunsa formation, Hongsan, Buyeo, were studied using electron probe micro analysis (EPMA). The average chemical composition of mica-type mineral is $(K_{1.11}Na_{0.26}Ca_{0.04})(Al_{3.93}Fe_{0.21}Mg_{0.07})(Si_{6.08}Al_{1.92})O_{20}(OH)_4$, and shows a characteristics of the so-called illite with a low content of interlayer cations and Fe, Mg in octahedral sites. The mica-type mineral shows a typical chemical composition of the mixed-phase among muscovite, pyrophyllite, and chlorite (mixed-phase muscovite, $Mu_{70.5}Py_{23.5}Ch_{6.0}$). The staurolite, in general, occurs with the mixed-phase muscovites, pyrophyllites, and aluminosilicates in the rock. We consider that staurolite can be formed by a reaction involving pyrophyllite such as pyrophyllite+chloritoid. The chloritoid is formed by a reaction between pyrophyllite and chlorite and is supposed to be used up in the process of staurolite formation. As a result, the mixed-phase muscovite, formed during the transition of illite to muscovite, plays an important role for the generation of the staurolite. Considering that the reaction occurs at the temperature higher than $300^{\circ}C$ and pyrophyllites transform into aluminosilicates at $350^{\circ}C$, the shale in the Baekunsa formation can be considered to have been experienced a metamorphic temperature between $300{\sim}350^{\circ}C$.

• Journal of environmental and Sanitary engineering
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• v.21 no.3 s.61
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• pp.37-43
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• 2006

Recently, needs for reuse of sludge produced from WTP(water treatment plant) have been increased with shortage of landfill sites and difficulties of the treatment and disposal processes. Therefore, Reusing is becoming an Increasingly popular waste management alternative to divert waste from landfills. In order to research the characteristics of WTP sludges, we used the sludges of C WTP which intake the lake Dae-Cheong and the sludges of S WTP which intake Keum river, The specific surface area of C and S WTP sludges were $0.9986m^2/cc\;and\;1.874m^2/cc$, respectively. The gravity was about $2.0{\sim}2.4$ which are scope of peat or loamy clay. The major minerals of C WTP sludges were kaolinite(48.4%), muscovite(19.5%), and quartz(16.7%). Also, muscovite(31.6%), quartz(30.3%), and kaolinite(17.3%) in S WTP sludges were major minerals.

• Corrosion Science and Technology
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• v.9 no.6
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• pp.265-269
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• 2010

This paper describes the exfoliation and surface modification of muscovite mica for UV coating formulation. For the exfoliation of the mica, hydrothermal process was used in the presence of lithium nitrate ($LiNO_3$). After the cation exchange with $Li^+$ ions, the surface of the mica was modified with several amphiphilic substances to increase compatibility and storage stability in UV coating formulation. Such a hydrophobic surface modification affected colloidal stability as well as dispersibility of the exfoliated mica in UV coating solution. Anticorrosive property of mica/UV coated steel plates was tested by salt spray test (SST) and compared with sodium montmorillonite ($Na^+$-MMT)/UV coated steel plates.