비스(트리메틸실릴메틸)메톡시비닐실란의 합성

오형식,장주환 木浦大學校 基礎科學硏究所 1994 基礎科學硏究誌 Vol.12 No.-

비스(트리메틸실릴메틸)디클로로실란은 구리와 카드뮴을 각각 촉매와 조촉미로 사용하어 320 ℃에서 클로로메틸트리메틸실란을 금속규소와 직접반응에 제조하였다. 비스(트리메틸실릴메틸)디클로로실란을 메틸알콜과 반응시켜 비스(트리메틸실릴메틸)클로로메톡시실란을 합성하였고, 이를 비닐 그리냐르시약과 반응시켜 비스(트리메틸실릴메틸)메톡시비닐실란을 합성하였다. Bis(trimethylsilylmethyl)dichlorosilane has been prepared in 71% yield by the direct synthesis of α-chloromethylsilanes with metallic silicon in the presence of copper catalyst and cadmium cocatalyst using a spiral band agitator at the carefully controled temperature at 320℃ and we prepared the bis(trimethylsilymethyl)methoxyvinylsilane prepared by Grignard reaction in 63% yield.

울산단층 동부지역 제4기단층 비지대의 체적변화와 유체-암석비에 대한 고찰

장태우 ( Tae Woo Chang ),채연준 ( Yeon Zoon Chae ),추창오 ( Chang Oh Choo ) 대한지질공학회 2005 지질공학 Vol.15 No.3

울산단층 동부 지역에는 제4기로 추정되는 미고결 퇴적층을 절단하며 파쇄대와 단층비지를 수반하는 제4기 단층이 여러 곳에서 발견되고 있다. 본 연구에서는 제4기 단층비지대의 성분변화, 체적변화, 실리카의 손실 그리고 유체-암석 비를 XRF, XRD, EPMA를 이용하여 계산하였다. 단층비지의 성분변화는 모암에 비해 단층비지대에서 SiO2, K2O, Na2O는 감소하고, Al2O3, MgO, P2O5, Fe2O3, MnO, CaO, LOI는 증가한다. 단층별 체적감소는 개곡 제1단층 56%, 개곡 제2단층 22%, 신계단층 34%, 마동단층 8%, 원원사단층 2%, 진현단층 53% 이다. 체적감소, 실리카 손실, 유체-암석비가 낮게 나타난 마동단층과 원원사단층 비지대는 유체활동에 대하여 닫힌계이고, 체적감소, 실리카 손실, 유체-암석 비가 높은 개곡 제1단층과 진현단층의 비지대는 유체 활동의 통로로 작용한 열린계였을 것으로 볼 수 있다. 단층의 유체-암석 체적비는 모든 단층에서 102~104로 나타나지만 기질의 함량이 각각 88%와 77%로 높고 체적감소가 큰 개곡 제1단층과 진현단층에서 가장 높게 나타난다. 따라서 이들 단층에서 유체의 활동이 가장 활발하였다. Many Quaternary faults are recognized as thin gouge and narrow cataclastic zone juxtaposing the Bulguksa granite and Quaternary deposit bed in the eastern block of the Ulsan Fault, Korea: Gaegok 1, Gaegok 2, Singye, Madong, Wonwonsa and Jinhyeon faults. This study was performed to calculate chemical change, volume change, silica loss and fluid-rock ratio taken place in gouge zones of these Quaternary faults using XRF, XRD, EPMA. The chemical compositions of fault rocks reveal that the fault gouges are depleted in SiO2, Na2O and K2O and enriched in Al2O3, Fe2O3, P2O5, MgO, MnO CaO and LOI(H2O+CO2) relative to protoliths. The fact that there is enrichment of relatively immobile elements and depletion of the more soluble elements in the fault gouges relative to protoliths can be explained by fluid-assisted volume loss of 56% for Gaegok 1 fault, 22% for Gaegok 2 fault, 34% for Singye fault, 8% for Madong fault, 2% for the Wonwonsa fault and 53% for the Jinhyeon fault. Madong fault and Wonwonsa fault where ratios of the volume change, silica loss and fluid-rock are low might have acted as a closed system for fluid activity, whereas Gaegok 1 fault and Jinhyeon fault with high ratios in those factors be an open system. The volumetric fluid-rock ratios range 102~104 for all faults, being highest in Gaegok 1 fault and Jinhyeon fault whose fluid activity was most significant.

Identification and Three-Dimensional Characterization of Micropore Networks Developed in Granite using Micro-Focus X-ray CT

( Chang Oh Choo ),( Manabu Takahashi ),( Gyo Cheol Jeong ) 대한지질공학회 2014 지질공학 Vol.24 No.2

We analyzed the three-dimensional distribution of micropores and internal structures in both fresh and weathered granite using micro-focus X-ray computed tomography (micro-CT). Results show that the pore radius in fresh graniteis mostly in the range of 17-50 μm, the throat radius is in the range of 5-25 μm, and the coordination number(CN) of pores is less than 10. In contrast, the pore radius in weathered granite is mostly in the range of 20-80 μm, the throat radius is in the range of 8-30 μm, and the CN is less than 12. In general, a positive linear relationship exists between pore radius and CN. In addition, both the size and the density of pores increase with an increasing degree of rock weathering. The size of the throats that connect the pores also increases with an increasing degree of weathering, which induces fracture propagation in rocks. Micro-CT is a powerful and versatile approach for investigating the three-dimensional distributions of pores and fracture structures in rocks, and for quantitatively assessing the degree of pore connectivity.

Paleoseismic Evidence by Pseudotachylite Occurring in Deep Core Drilling Products in Granite and Granitic Gneiss, Andong, Korea

( Chang-oh Choo ),( Suhyeon Jo ),( Gyo-cheol Jeong ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Pseudotachylite, characterized by dark colored rock with glassy texture, occurs in deep core samples drilled up to 900 m from the surface, Andong, Korea where host rocks are composed of granite and granitic gneiss. Pseudotachylite has a range from a few to 20 cm in width, occurring at varying depths with different texture and thickness. Although brittle failure is common in the whole core samples, pseudotachylite was commonly found at random depth intervals. We analyzed pseudotachylite samples and fault materials in drilled core samples using X-ray diffraction (XRD) quantitative analysis and scanning electron microscope (SEM). The pseudotachylite surface is characterized by a smooth, glassy matrix. Quartz and ilmenite (TiO2) as residual grains in glassy matrix occur as micron size, accompanying embayed textures. Such evidence supports that pseudotachylite was generated through friction melting due to seismic events. According to XRD results, fractured materials are composed of several minerals: quartz, feldspars, hornblende, micas, and secondary minerals including clay minerals, calcite, and glassy matrix. Mineralogical assemblages suggest that paleoseimic event forming pseudotachylite took place around at most 300 °C, roughly corresponding to moderate depths, possibly 10 km. Although identification of pseudotachylite in deep drill cores is not easy without textural and mineralogical analyses, it has significant potential for better understanding paleoseismic event.

Mineralogical studies on complex zoned tourmaline in diaspore nodules from the Milyang clay deposit,Korea

Chang Oh Choo 한국지질과학협의회 2003 Geosciences Journal Vol.7 No.2

Tourmaline occurs as aggregates or disseminatedcrystals in the clay matrix of diaspore nodules from the Milyangclay deposit located in southeastern Korea. The diaspore nodulesoccur along or near the fractured zones developed in the clay deposit.Most tourmalines are dravite to schorl in chemical compositionand show complex chemical zonal textures. Chemical analyses andBSE images confirm that alternating Fe-rich and Mg-rich bandsare the most important components that controlled patterns ofchemical zoning in tourmaline. Mg was enriched in the early stageof crystal growth while Fe was enriched in the late stage, with fluc-tuations of the ratio Fe/Mg. Complex multiple growth zoning andoscilatory zoning in tourmaline imply local disequilibrium of thehydrothermal alteration system that formed diaspore nodules. As theoxygen fugacity increased, tourmaline became more Fe-rich withfluctuation of Fe/Mg activity. Textural observations indicate thattourmaline was unstable with respect to dickite. The aluminum-richminerals associated with diaspore nodule suggest that the growthof tourmaline may be highly favorable with alkali-free composi-tions with trace Na.

Mineralogical and geochemical controls on the formation of schwertman-nite and goethite in the wetland at Dalseong tungsten mine, Korea

Chang Oh Choo,Jin Kook Lee 한국지질과학협의회 2002 Geosciences Journal Vol.6 No.4

Schwertmannite and goethite are the most impor-tant minerals of ochreous precipitates from the wetland of theDalseong tungsten mine near southern Daegu. The main factorleading to precipitation of goethite and schwertmannite is the pHof the solution. Schwertmannite forms as a dominant mineralphase below pH 3.5. Formation of goethite takes place at the inlet,whereas schwertmannite predominantly precipitates at both thedownstream pond and outlet. Schwertmannite shows bundle ofneedle morphology with a similar range in size and its fine needlescoalesce to form rounded aggregates. Needles are approximately0.1-0.5 mm long and 0.1 mm wide. Decreasing pH at the down-ward ponds is attributed to formation of schwertmannite fromwater with high content of iron and sulphate ion. The removal rateof sulphate ion at downstream ponds is unremarkable possiblydue to supply of sulphate ion by organic decay in the reductionponds, although high content of sulphate ion is removed by form-ing schwertmannite. As precipitation of schwertmannite proceeds,iron is actively consumed and pH decreases.

Crystal Chemistry of Dumortierite : NMR and FTIR results

Chang Oh Choo,Yeongkyoo Kim 대한지질학회 2001 대한지질학회 학술대회 Vol.2001 No.

Mineralogical evidence for red coloration of sandstones at the Chilgok Formation of the Cretaceous Hayang Group, Southeastern Korea

Chang Oh Choo,Young Sik Shin,In Seok Koh 한국지질과학협의회 2002 Geosciences Journal Vol.6 No.2

The present study was focused on red sandston bedsoccurring in the Chilgok Formation, lower Hayang Group of Cre-taceous age. Red sandstones consist mainly of plagioclase, quartz,and volcanic rock fragment, with accessory minerals such asbiotite, chlorite, pyroxene, hornblende, leucoxene, ilmenite, sphene,pyrite, and hematite. Volcanic rock fragments composed of pyrox-ene, plagioclase, and glass material are intensively altered. Red-dening of sandstones was preferentially attributed to the presenceof hematite, Fe- and Ti-bearing minerals. Hematite pigmentationwas largely caused by post-depositional disolution of Fe-silicatessuch as chlorite, biotite, and amphibole. Diagnostic alteration ofmafic minerals as wel as Ti-bearing minerals, together with clayminerals, indicates that pigmentary materials in the red bedsinherited from diagenetic sources in the depositional basin, possi-bly during early diagenesis.

Occurrence of Dolomite in Yangsan Fault, Yeongdeok, Gyeongbuk, Korea, and Implications for Possible Fault Activity Related to Seawater

( Chang-oh Choo ),( Suhyeon Jo ),( Gyo-cheol Jeong ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

This study focused on characterization of dolomite occurring in Yangsan Fault, Namsan-ri, Yeongdeok, Korea and provided implications for possible fault activity related to seawater. Dolomite was commonly identified as veinlets or irregular lenticular pocket in volcanic rocks, suggesting specific origin so called hydrothermal dolomite (HTD). The fault is characterized by a fault core with 1.2 m thickness and the fault planes have N40~50E/74~80SE. Brecciated fragments and veinlets develop in the fault zone where fault gouge with 10 cm thickness is observed, though negligible in some places. We analyzed fractured materials collected from the fault core using photomicroscope on thin sections, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Main mineralogy of fractured materials consists of quartz, illite, dolomite, pyrite, and iron oxides. Quartz as residual grains in gouge indicates that it experienced size reduction with grain rotation during faulting. It was assumed from field and textural observations that dolomite formed right after main fault event, possibly due to seismic pump effect or injection of seawater associated with highly brine deep water. HTD has implications for fault activity related to seawater in northern part of the Yangsan Fault, quite different from that found in other sites of the fault. The research was supported by Earthquake disaster prevention specialist training funded by Administration safety, Korean government.

피압대수층 지하수내 질소함유 원인연구: 질소, 산소, 수소동위원소 적용

추창오 ( Chang Oh Choo ),이병대 ( Byung Dae Lee ),조병욱 ( Byung Wook Cho ),성익환 ( Ig Hwan Sung ),지세정 ( Se Jung Chi ) 대한지질공학회 2002 지질공학 Vol.12 No.3