• Proceedings of the Mineralogical Society of Korea Conference
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• 2003.05a
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• pp.52-52
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• 2003

경기육괴 서남부에 위치한 홍성지역의 기반암은 선캠브리아 화강암질 편마암으로 이루어진 것으로 알려져 왔으나, 적어도 일부는 신원생대(약820 Ma) 시기에 관입한 토날라이트질 심성암체로 구성된다. 토날라이트의 주 구성광물은 석영, 사장석, 흑운모, 각섬석이며, 저어콘, 스핀, 녹니석, 인회석 등이 소량으로 산출한다. 이 연구에서는 야외 및 미세구조 관찰을 통해, 홍성 화강암질암에서 나타나는 구조적 요소들이 화성기원임을 보고한다. 홍성 토날라이트에서 관찰되는 구조들이 화성기원인 증거는: (1) 엽리가 연속성이 부족하고 주향과 경사가 불규칙하며, 드물게는 사층리처럼 보이기도 한다. (2) 자형 내지 반자형의 장석과 각섬석이 엽리면에 평행 또는 준평행하게 배열되어 있으며, 반정 주변에는 음영대(pressure shadow)가 발달하지 않는다 (3) 고철질 포획체(mafic enclave)는 주변암의 엽리에 평행하게 신장되어 있고, 완전히 고화 되지 않은 상태에서 형성되는 불꽃 구조(flame structure)가 드물게 관찰된다. (4) 고철질 포획체의 주 구성광물인 흑운모와 각섬석은 주변암의 엽리와 평행하게 배열되어 있으나, 소성변형의 증거를 보이지 않는다. 홍성 토날라이트에서 관찰되는 모든 조직들이 화성기원이라고 주장하기는 어렵지만, 모두 고체상태에서의 변형작용으로 설명하기는 더욱 힘들다. 후자가 화성기원의 조직에 어느 정도 영향을 주었는지는 추후의 연구를 통해 밝혀져야 할 것이다.

• Journal of the Mineralogical Society of Korea
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• v.3 no.2
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• pp.79-88
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• 1990

고령토의 조직과 산출상태의 관찰결과 산화철 광물을 침전시킨 철의 주요 근원은 모암인 회장암에 함유된 각섬석과 녹니석이다. X선 회절 분석결과 침철석은 녹니석이 버미큘 라이트로 변질되고 각섬석이 용해되기 시작하는 하부 백색 광석에서 우세하며, 적철석은 각섬석, 녹니석 및 버미큘라이트가 심한 용탈작용을 받는 상부 적갈색 광석이나 열 개에서 침철석과 함께 산출된다. 침철석 및 적철석내 Fe에 대한 Al의 치환량은 각각 6~26 mol% 및 5~8mol%이며 이 두 값 사이에는 비례 관계가 있다. 회절선폭의 크기로부터 계산된 침철석과 적철석의 평균 입자크기는 340$\AA$ 이하이며 침철석은 약간의 침상을 보이는 반면 적철석은 탁상이다. 전자현미경 관찰에 의하면 버미큘라이트와 수반되는 침철석은 침상 또는 성상이나 적갈색 광석에서는 그러한 특징이 작다. 적철석은 육각 또는 원형을 보이나 상부 적갈색 광석에서는 보다 불？칙한 모양이다. 적철석과 침철석의 광물학적 특성을 합성실험에서 보고된 결과들과 비교하여 성인적 측면에서 논의되었다. 이 지역에서는 침철석과 적철석의 생성에 적합한 기후조건들이 중첩된 것으로 생각된다.

• Korean Journal of Materials Research
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• v.7 no.4
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• pp.347-353
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• 1997

BaTiO$_{3}$물질은 뛰어난 유전체로 널리 알려져 왔으며 특히 Heywang등이 제안한 PTCR특성은 이 물질의 응용범위를 세라믹 필터, 회로보호소자, 온도감지소자 및 저항가열장치 등으로 확대시켰다. 이러한 특성의 발현기구는 아직까지 밝혀지지 않은 상태이지만 제 특성을 향상시키기 위한 노력은 계속되어왔다. 특히 개발목적에 맞게 온도에 따른 정저항 특성(PTCR; Positive temperature constnat of resistivity phenomena)을 설계하려는 시도가 계속되어 왔으며 그 중에서도 페로브스카아트계의 2가와 4가의 양이온 자리를 등가나 원자가가 다른 양이온으로 치환하여 특성을 개선하려는 시도가 계속되어 왔다. 특히 $Ca^{2+}$나 Sr$^{2+}$는 $Ba^{2+}$자리를 치환할 수 있는 물질로 개별적인 첨가에 대한 연구는 많은 연구자들에 의해 진행된 상태이지만 최종적인 영향이나 해석에 대해서는 연구자들간에 이견이 많은 상태이다. 이번 실험에서는 BaTiO$_{3}$계에 합성한 (Ca, Sr)TiO$_{3}$를 Ca와 Sr의 상대적인 비를 변화시키면서 전체적인 첨가량을 변화시켜 그에 따른 전기적 특성 및 미세구조를 살펴보았다. (Ca, Sr)TiO$_{3}$의 첨가로 상온저항 및 PTCR특성을 변화시킬 수 있었으며 이를 통해 PTCR물질의 활용범위를 넓힐 수 있는 발판을 마련할 계기가 되었다. 특히 기존의 연구가 주로 개별적인 Ca나 Sr의 첨가에 의한 미세구조와 전기적 특성변화의 연구에 치중해 있었던 것과는 달리 Sr과 Ca을 함께 치환하여 상대적인 비가 특성에 더 중요한 영향을 끼치는 것을 확인하였으며 적절한 합성비를 선택하면 퀴리온도에서의 저항변화폭을 유지하면서 상온저항을 낮출 수 있음을 확인하였다.문했던 연구소인 Shanghai Research Center of Biotechnology, Shanghai Institute of Industrial Microbiology 및 Scientific Research Institute of Food and Fermentation Industry을 소개하고저 한다. 짧은 기간의 방문이라 주로 해당연구소의 자체소개 자료를 중심으로 방문하면서 느낀점을 기술하고저 한다.초염기성암 기원의 사문암이 열수변질작용을 받아 생성되었음을 명확하게 지시하며, 따라서 활석 광석내에 존재하는 녹니석은 활석의 근원 광물로서 녹니석편암 및 녹니석 편마암 매의 녹니석이 활석화되고 남은 잔존광물이 아니라, 주변암에 의해 성분상의 영향을 받은 열수와 사문암과의 변질교대작용에 의한 활석화과정 중에 주로 생성된 것으로 추정된다. 이러한 결과는 연구지역의 활석광상이 초염기성암의 사문암화 작용과 활석화 작용의 두 가지 변질작용에 의해 형성되어졌음을 알려준다.농도 증가 없이 폐 조직에 약 50배 정도의 고농도 cisplatin을 투여할 수 있었으며, 또한 분리 폐 관류 시 cisplatin에 의한 직접적 폐 독성은 발견되지 않았다이 낮았으나 통계학적 의의는 없었다[10.0%(4/40) : 8.2%(20/244), p>0.05]. 결론: 비디오흉강경술에서 재발을 낮추기 위해 수술시 폐야 전체를 관찰하여 존재하는 폐기포를 놓치지 않는 것이 중요하며, 폐기포를 확인하지 못한 경우와 이차성 자연기흉에 대해서는 흉막유착술에 더 세심한 주의가 필요하다는 것을 확인하였다. 비디오흉강경수술은 통증이 적고, 입원기간이 짧고, 사회로의 복귀가 빠르며, 고위험군에 적용할 수 있고, 무엇보다도 미용상의 이점이 크다는 면에서 자연기흉에 대해 유용한 치료방법임에는 틀림이 없으나 개흉술에 비해 재발율이 높고 비용이 비싸다는 문제가 제기되고 있는 만큼 더 세심한 주의와 장기 추적관찰이 필요하리라 사료된다.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.335-349
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• 2014

The Pocheon skarn deposit, located at the northwestern part of the Precambrian Gyeonggi massif in South Korea, occurs at the contact between the Cretaceous Myeongseongsan granite and the Precambrian carbonate rocks, and is also controlled by N-S-trending shear zone. The skarn distribution and mineralogy reflects both structural and lithological controls. Three types of skarn formations based on mineral assemblages in the Pocheon skarn exist; a sodiccalcic skarn and a magnesian skarn mainly developed in the dolostone, and a calcic skarn developed in the limestone. Iron mineralization occurs in the sodic-calcic and magnesian skarn zone, locally superimposed by copper mineralization during retrograde skarn stage. The sodic-calcic skarn is composed of acmite, diopside, albite, garnet, magnetite, maghemite, anhydrite, apatite, and sphene. Retrograde alteration consists of tremolite, phlogopite, epidote, sericite, gypum, chlorite, quartz, calcite, and sulfides. Magnesian skarn mainly consists of diopside and forsterite. Pyroxene and olivine are mainly altered to tremolite, with minor phlogopite, talc, and serpentine. The calcic skarn during prograde stage mainly consists of garnet, pyroxene and wollastonite. Retrograde alteration consists of epidote, vesuvianite, amphibole, biotite, magnetite, chlorite, quartz, calcite, and sulfides. Microprobe analyses indicate that the majority of the Pocheon skarn minerals are enriched by Na-Mg composition and have high $Fe^{3+}/Fe^{2+}$, $Mg^{2+}/Fe^{2+}$, and $Al^{3+}/Fe^{2+}$ ratios. Clinopyroxene is acmitic and diopsidic composition, whereas garnet is relatively grossular-rich. Amphiboles are largely of tremolite, pargasite, and magnesian hastingsite composition. The prograde anhydrous skarn assemblages formed at about $400^{\circ}{\sim}500^{\circ}C$ in a highly oxidized environment ($fO_2=10^{-23}{\sim}10^{-26}$) under a condition of about 0.5 kbar pressure and $X(CO_2)=0.10$. With increasing fluid/rock interaction during retrograde skarn, epidote, amphibole, sulfides and calcite formed as temperature decreased to approximately $250^{\circ}{\sim}400^{\circ}C$ at $X(CO_2)=0.10$.

• Journal of the Mineralogical Society of Korea
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• v.31 no.1
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• pp.1-12
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• 2018

A gravity core (RS14-C2) was collected at site RS14-C2 in the continental slope to the east of Pennell-Isellin Bank of the Ross Sea (Antarctica) during PNRA XXIX (Rosslope II Project) Expedition. In order to trace the sediment source, magnetic susceptibility (MS), sand fraction, and clay mineral compositions were analyzed, and AMS $^{14}C$ ages were dated. Core sediments consist mostly of hemipelagic sandy clay or silty clay including ice-rafted debris (IRD). AMS $^{14}C$ age of core-top indicates the modern and Holocene sediments. Based on AMS $^{14}C$ dating, sediment color, MS and sand fraction, core sediments are divided into interglacial and glacial intervals. The interglacial brown sediments are characterized by low MS and sand fraction, whereas the glacial gray sediments are characterized by high MS and sand fraction. Among clay mineral compositions of core sediments, illite is highest (61.8~76.7%), and chlorite (15.7~21.3%), kaolinite (3.6~15.4%), and smectite (0.9~5.1%) are in decreasing order, and these compositions are also divided into the interglacial and glacial/deglacial intervals. During the glacial period, the high content of illite and chlorite indicate sediment supply from the bedrocks of Transantarctic Mountains under the Ross Ice Sheet. In contrast, because of decreasing supply of illite and chlorite by the glacial retreat, smectite and kaolinite contents increased relatively during the interglacial period. During the interglacial period, smectite may be transported additionally by the northeastward flowing surface current from the coast of Victoria Land in the western Ross Sea. Kaolinite may be also supplied to the continental slope by the Antarctic Slope Current from the kaolin-rich metasedimentary rock outcropped on the Edward VII Peninsula.

• Korean Journal of Heritage: History & Science
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• v.54 no.2
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• pp.4-21
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• 2021

A stone mold from the Sabi period of Baekje was excavated at the western tombs in Neungsan-ri, Buyeo where there was a recent excavation survey (2016). It was believed and reported that such stone molds were used for copper needles during the early Iron Age; however, a close re-examination of the form revealed that they were used for bifid ornamental hairpins. Given its casting form, the stone mold of Neungsan-ri is estimated to have been used to make bifid ornamental hairpins in a ∩ shape, narrowing down toward the tip. It is considered an artifact of the Goryeo dynasty. The stone used to make the bifid ornamental hairpin mold of Neungsan-ri was chlorite-schist, the principal minerals of which include chlorite, amphibole, and talc. Similar rocks are in nearby Buyeo (Oesan-myeon), Cheongyang, Gongju, and Yesan. They are mainly found between Jiseon-ri, Oesan-myeon, Buyeo, Sucheol-ri, Yesane-up, and Yesan. Nearly 70 bifid ornamental hairpins from the Goryeo dynasty were excavated at Neungsan-ri, Buyeo and the surrounding areas. Among them, the bronze ones excavated from the tombs of Songguk-ri, Buyeo are estimated to have been made using this mold as they closely resemble the Neungsan-ri mold. Stone was likely the preferred material for molds to make bronze artifacts as it was easy to sink a die. Regarding the bifid ornamental hairpin cast excavated in Neungsan-ri, they obtained stones in nearby areas 20~50km from their location, made bronze artifacts, and distributed them to nearby sites during the Goryeo dynasty. These artifacts suggest that the casting technology of using a stone mold was still employed then.

• Journal of the Mineralogical Society of Korea
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• v.16 no.1
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• pp.49-63
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• 2003

Rare and unusual occurrence of hydrothermal minerals were found in Geode mine area. They are developed in the late stage of hydrothermal alteration of earlier skarns and later by the open-space filling crystallization. The alteration of earlier skarns of clinopyroxene, garnet, and plagioclase formed mainly chlorite or sometimes uncommon hydrothermal minerals of prehnite, illite, and pumpellyite. Open-space filling crystallization characterized by hydrothermal minerals developedin open sapce or good are prehnite, pumpellyite, clinozoisite, illite, and Ca-zeolites of stilbite annstellerite. Mineral phases and paragenesis are examined in detail by microscopy, XRD, SEM, and EPMA. Using the Schreinemaker's method, equibrium reactions among these minerals are establishedand isothemal-isobaric phase diagrams of $\mu$$H_2O$-$\mu$$CO_2$cot are plotted. Hydrothermal minerals such asprehnite, pumpellyite, clinozoisite, illite, and some chlorite were ffrmed under high partial pressure of $CO_2$with relatively low $H_2$O fugacity. Later, stilbite and calcite in association with illite crystallized under relatively both high partial Pressure of $CO_2$and high $H_2$O fugacity.

• The Journal of the Petrological Society of Korea
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• v.3 no.2
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• pp.138-155
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• 1994

Granitic gneiss containing biotite banded gneiss relict around the Daeheung talc deposit are widely distributed which were formed by regional metamorphism of both epidote-amphibolite and iater greenschist facies and granitization. They were derived from same silico-aluminous rocks of sedimentary origin. The mineral assemblages, which are common in the biotite banded gneiss, formed during regional metamorphisms, are survived in the granitic gneiss. The mineral assemblages of the latter greenschist facies may be formed retrogressively from the first epidote-amphibolite facies. The chemical compositions of biotite, muscovite, and chlorite, the important constituents of the gneisses, were controlled by the bulk composition, the chemical composition of the original mineral, and environment of the regional metamorphisms and granitization. The chemical equilibrium between coexisting'minerals, especially biotite and muscovite, is relatively well established, which was controlled mainly by tschermakitic and phengitic substitutions. Cholrite was formed mainly from either biotite or muscovite by retrogressive alteration or granitization, and have nearly similar chemical compositions regardless of the occurrences. The orientation trend of the foliation, joint and quartz vein developed in the gneisses was analyzed by equal area projection which the latter two show nearly identical trend in the strike and dip. This may suggest that the hydrothermal solution was introduced along joint during wet granitization.

• Journal of the Mineralogical Society of Korea
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• v.17 no.3
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• pp.189-199
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• 2004

Cretaceous sedimentary rocks bearing dinosaur tracks in the Goseong interchange area were studied for their conservation and public display in the aspect of applied mineralogy. Black clay layers alternate with silt layers in the sedimentary rocks. The verical and horizontal fissures are commonly filled with calcite veinlets, supergenetic iron and manganese oxides. The rocks are composed of quartz, albite, K-feldspar, calcite, chlorite, illite, muscovite, and biotite, with minor apatite and rutile. Silt layers are relatively rich in calcite and albite, whereas clay layers are abundant in quartz, illite, and chlorite. Al, Fe, Mg, K, Ti, and P are enriched in the clay layers, while Ca, Na, and Mn in silt. Most of trace elements including V, Cr, Co, Ni, Cs, Zr, REE, Th, and U are enriched in clay layers. Inorganic carbon are present in silt layers as calcite, while organic carbon in black clay layers. The black clay layers were partly altered to yellow clay layers along the fissures, simultaneously with the decrease of organic carbon. Selective exfoliation of clay-rich black and yellow clay layers, calcite matrix of silt layers and calcite infillings of fissures are estimated as the major weakness potentially promoting chemical and physical degradation of the track-bearing rock specimens.

• The Journal of the Petrological Society of Korea
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• v.2 no.2
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• pp.95-103
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• 1993

The geology of the talc ore deposits in the Chungju area consists of the Kyemyeongsan Formation, the Munjuri Formation, the Daehyangsan Quartzite, the Hyangsanni Dolomite, and the basic rocks of the Ogcheon belt. The talc ore occurs in the Hyangsanni Dolomite near the Daehyangsan Quartzite The mineral assemblages in the Hyangsanni Dolomite are \circled1calcite-tremolite-talc-quartz, \circled2calcite-talc-quartz, \circled3tremolite-calcite-dolomite, and \circled4calcite-dolomite-phlogopite-chlorite. Talc has almost the ideal composition($X_{Mg}$=Mg/(Fe+Mg)=0.98). Talc was formed in siliceous dolomite by the medium-pressure type regional metamorphism. The evidences for contact metamorphism and/or hydrothermal reaction are not clear. The metamorphic grade of the Hyangsanni Dolomite and its adjacent pelitic or basic rocks near the deposits corresponds to epidote-amphibolite facies or greenschist facies based on the, mineral assemblages of \circled1hornblendebiotite-muscovite-epidote-quartz \circled2biotite-chlorite-quartz, and \circled3hornblende-actinolite-plagioclasequartz. The formation of the talc deposits were caused by the following reactions due to greenschist facies metamorphism of siliceous-dolomitic rocks in the Hyansanni Dolomite. (I) 3 dolomite+4 quartz+$H_2O$= talc+ 3 calcite +3 $CO_2$; (11) 3 tremolite+ 2 $H_2O$+ 6 $CO_2$= 5 talc+ 6 calcite + 4 quartz. The minimum temperature of the talc-tremolite-quartz assemblage is about $434^{\circ}C$ from calcite thermometry and the carbon dioxide mole fraction in metamorphic fulid($X_{$CO_2$}$) is about 0.1 at assumed pressure, 3 kbar.