• Journal of the Mineralogical Society of Korea
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• v.16 no.2
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• pp.181-189
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• 2003

Diverse microtextures and secondary minerals formed by chemical weathering were observed in the glacial debris of King George Island. Weathering rind was observed in the block of basaltic andesite tuff due to dissolution of calcite producing voids. Eolian volcanic glass altered to mixtrure of allophane-like materials and iron oxyhydroxides at grain edges with relative concentration of Al. Fe, and Ti. Biotite in granodiorite area was transfarmed to vermiculite and interstratified biotite-vermiculite or very rarely to kaolinite and gibbsite. Pyrite in the hydrothermal alteration zone was repalced by iron oxides, resulting in sulfuric acid which locally accelerated alteration of chlorite to expandable clay minerals. Weathering of plagiociase and K-feldspar was negligible. Although glacial debris of the Barton Peninsula has undergone weak chemical weathering with formation of some secondary minerals, massive formation of smectite, abundant in nearby marine sediments, didn't occur.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.3
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• pp.135-152
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• 1975

The following informations are known from physical and chemical characteristics of orchard soils and nutritional diagnosis of orange leaves in Jeju. 1. Most orange orchards are located on terrace and cindercone thus soil moisture and microclimate of an orchard will greatly be affected by its topography. 2. Excessive well drainage, shallow soil depth, high content of gravels, low solid phase ratio and strong wind will give severe problem of soil moisture and wind errosion, thus the exte- nsion of soil depth is necessary for maintain nutrients, water and sufficient root volume. 3. Available soil water was significantly and positively correlated with organic matter content and clay content also contributes to available soil water. Vinyl mulching was greatly helpful for soil water conservation, wind errosion prevention, soil temperature increases during winter. 4. Abundant amphoteric amorphous allophane take a key role to fix phosphorus and also rations and thus it is the major factor to determine fertilizer efficiency. Lime and phosphorus must be applied in deeper soil layer. Release of filed phosphorus must be reevluated for availability. 5. Organic matter such as see weeds will greatly increase fertilizer efficiency and low fertilizer efficiency during spring may be related to available soil water. 6. Nitrogen was in superoptimum and Mg was enough but P and Ca were somewhat deficient according to leaf analysies while K was deficient according to fruit analysis. Phosphorus application increased sugar/acid ratio and potassium decreases rind percentage. 7. Manganese deficiency and toxicity appeared in a few places. Iron and boron were enough. Most places showed tendency of copper excess but some places showed copper deficiency. 8. Soiling after elimination of rock base, application of slow release fertilizer and abundant organic matter, vinyl mulching and drip irrigation will increase fertilizer efficiency greatly and fruit yield drastically.

• Journal of the Mineralogical Society of Korea
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• v.21 no.2
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• pp.161-175
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• 2008

The soil developed from volcanic ash in Jeju Island, Korea, were classified as typical Andisols. The soils had acidic pH, high water contents, high organic matters and clay-silty textures. The crystalline minerals of the samples were mainly composed of ferromagnesian minerals such as olivine and pyroxene, and iron oxides such as magnetite and hematite derived from basaltic materials. A large amount of gibbsite was found at the subsurface horizon as a secondary product from the migration of excessive aluminum. In addition, our study has shown that considerable amounts of poorly ordered minerals like allophane and ferrihydrite were present in Jeju soils. The contents of $SiO_2$ were lower than those of other soil orders, but $A1_2O_3$ and $Fe_2O_3$ contents were higher. These results are some of the important chemical properties of Andisols. The contents of heavy metals were in the range of $84{\sim}198$ for Zn, $56{\sim}414$ for Ni, $38{\sim}150$ for Co, $132{\sim}1164\;mg\;kg^{-1}$ for Cr, which are higher than the worldwide values in most of the soils. Some soil samples contained relatively high levels of Cr exceeding 1000 mg/kg. Mean reduction capacity of the Jeju soils was $6.53\;mg\;L^{-1}$ reduced Cr(VI), 5.1 times higher than that of the non-volcanic ash soils from inland of Korea. The soil reduction capacity of the inland soils had a good correlation with total carbon content (R = 0.90). However, in spite of 20 times higher total carbon contents in the Jeju soils, there was a week negative correlation between the reduction capacity and the carbon content (R = -0.469), suggesting that the reduction capacity of Jeju soils is not mainly controlled by the carbon content and affected by other soil properties. Correlations of the reduction capacity with major elements showed that Al and Fe were closely connected with the reduction capacity in Jeju soil (R = 0.793; R = 0.626 respectively). Moreover, the amounts of Ni, Co and Cr had considerable correlations with the reduction capacity (R = 0.538; R = 0.647; R = 0.468 respectively). In particular, in relation to the behavior of redox-sensitive Cr, the oxidation of the trivalent chromium to mobile and toxic hexavalent chromium can be restricted by the high reduction capacity in Jeju soil. The factors controlling the reduction capacity in Jeju soils may have a close relation with the andic soil properties explained by the presence of considerable allophane and ferrihydrite in the soils.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.3
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• pp.135-151
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• 1977

The present paper summerizes the studies on clay mineralogical characteristics of Korean soil, relationship between potassium and clay minerals, potassium release pattern of clay minerals and utilization of clay minerals for soil conditioner and fertilizers, which have been carried out in this laboratory. 1. The red yellow podzolic soil is mostly abundant in the upland of Korea and mainly consists of halloysite and weathered intermediates of mica such as illite and vermiculite. 2. With regard to soil parent material, kaolin mineral occurs abundant in soils derived from granite and granite gneiss. Mica is dominant in basaltic soil. The main clay mineral of the soil, originated from the Tertiary, is found montmorillonite and the volcanic soil of Jeju Island has plenty of allophane as its main clay mineral. 3. It is confirmed that the soil fertility depends on the composition of clay minerals. The red yellow podzolic soil, containing lot of kaolin, shows low productivity while the montmorillonite soil has higher productivity. 4. The release rate of solid phase potassium (micas and fixed potassium) follows the 1st order reaction equation in the equilibrium solution of $IN-NH_4OAc$. The potassium release constant is positively correlated with the mica content of the clay but negatively correlated with the content of $14.5{\AA}$ minerals. On the other hand, the potassium release constant has very high correlation with the ratio(Kex/Kt) of exchangeable potassium(Kex) to total potassium(Kt). 5. It is also found that Kex/Kt has rather high correlation with the content of mica and $14.5{\AA}$ minerals existed in the clay as well as the mica content of the soil.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2001.06a
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• pp.115-115
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• 2001

경주시 양남면의 4기 단층으로 추정되는 수렴단층에 의해 절단되는 해안단구 퇴적층 풍화단면에서 저결정질 광물인 앨로패인 교결층을 기재하였다. 이들은 자갈퇴적층 내에 협재하는 수조의 모래층에 한정되어 형성되어 있으며, 3-17 cm 두께로 연장성이 매우 좋다. 편광현미경 관찰에 의하면 모래층에는 사장석편들이 다량 함유되어 있으며 앨로패인은 광학적 등방성의 치밀한 점토집합체들로서 사장석 입자를 선택적으로 교대하거나 자갈과 모래입자들을 피복하고 있다. 앨로패인은 광학적 이방성인 상하위층의 고령토질 점토피복물과 명확히 구분된다. 앨로패인의 전자현미분석에 의하면, Al/Si 원자비가 1.3-1.7 범위이고 평균값은 1.5이다. X선회절분석 결과 3.49$\AA$과 2.26$\AA$에서 두 개의 넓은 회절대가 관찰된다. 주사 및 투과전자현미경관찰에 의하면 앨로패인을 특정한 입자형태 없이 치밀한 겔상태를 이루고 있다. 열분석에 의하면 96$^{\circ}C$에서 큰 흡열피크와 992$^{\circ}C$에서 발열피크가 관찰되며, 총 45% 정도의 중량감소를 보인다. 사장석의 평균조성은 An$_{87}$이며, 사장석내 유리포유물의 전자현미분석결과는 화산암 화학분류도에서 현무암 영역에 도시된다. 이 지역의 기반암은 현무암질 라필리응회암이나 사장석편을 제외하고 벤토나이트화되어 있다. 따라서 해빈환경에서 사장석이 벤토나이트에서 분리되어 퇴적한 것으로 보인다. 앨로패인 교결층은 해수면 강하로 단구퇴적층이 지표로 노출된 후, Al의 함량이 높고 비교적 풍화에 약한 사장석이 선택적으로 풍화되어 생성되었다. 앨로패인으로 피복된 모래층 내의 자갈은 풍화반응이 지체되어 상하위층의 자갈과 비교하여 풍화도에 있어서 현저한 차이를 보인다.. 파이프 중심에서 외곽부로 갈수록 전기석의 함량은 줄어들고 있고 장석들이 알바이트ㆍ칼스베드 쌍정을 보이며, 흑운모가 각섬석보다는 우세하게 나타나고 있다. 전기석은 주상 결정, 자형 내지 반자형의 입자로 다색성을 보이며, 결정 중심에서 가장자리로 갈수록 파란색과 황갈색의 광학적 누대구조를 관찰할 수 있다. 일광광산에서 산출되는 전기석에 대한 현미경 관찰은 열수기원임을 지시하고 있다. 야외조사와 현미경 관찰의 예비조사에 의하면 일광광산의 전기석이 형성된 환경은 다른2가지 화학적인 저장소의 혼합 효과의 결과로 생성되어진 것으로 예상된다. 일광의 화강암류를 만든 마그마는 전기석을 형성할 만큼의 Fe-Mg성분이 충분하지 않았을 것이다. 화강암 내에 흑운모와 각섬석의 결정작용에 의해 마그마의 Fe-Mg성분이 고갈되어지고 이로 인해 그 함량이 감소하며 상대적으로 마그마 내에 남은 붕소(B$_2$O$_3$)는 열수로 용리되고 흑운모, 각섬석과 평형을 유지하며 열수에 남아있게 된다. 잔류용융체에 남은 붕소의 함량은 전기석을 만들기에 충분함에도 불구하고, Fe-Mg 함량이 부족하여 마그마 기원의 전기석 결정을 만들 수가 없다가 광맥이 형성된 시기에 또 다른 열수가 공급되면서 이전의 평형이 깨지고 기존의 흑운모와 같은 염기성 광물이 붕소(B)를 함유한 새로운 열수와 반응하여 전기석을 형성한 것으로 예상한다. 앞으로 전암과 광물에 대해 지화학적 연구를 통해 화강암류와 전기석과의 지화학적 연관성, 주성분 원소와 열수의 특성과의 상관관계, 전기석의 기원(마그마 기원인지 열수기원인지)이 보다 정확하게 파악될 것이다. 마그마 진화에 따른 전기석의 성분변화와 기원을 이용하여 일광광산의 동광화대를 형성한 마그마 계에서 열수계로 이어지는 지질학적 과정을 이해할 수 있을 것이며, 암석 성인론적 지시자로서

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.2
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• pp.65-70
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• 1980

This experiment was aimed at selecting the most suitable dispersing agent to the Korean soils. The particle size distribution of 18 soil samples representing the great soil groups in Korea was analysed with 5 different dispersing agents by pipette-method. Passing percent of 0.05, 0.02 and 0.002mm in diameter was used for the comparision of the dispersion capacity of chemical agents. The results obtained are as follows; 1. The influence of chemical agents on dispersion seemed to be greater to finer soil particles. The passing percents of 0.002mm showed a great differences according to the chemical agents used, while little differences was observed in those of 0.05mm. 2. It was showed that sodium pyrophosphate had the highest dispersion capacity for the most of Korean soils, the dispersion capacity of sodium hexametaphosphate was also high enough except for volcanic ash soils. 3. It was recommendable that sodium hexametaphosphate could widely be used as a dispersing agent in the routine analysis of soil particle size distribution except for the Volcanic ash soils. 4. The dispersion of Volcanic ash soils was rather poor when chemical agents used. Therefore, special care should be taken for the dispersion of allophane soils.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.501-507
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• 2009

Ordered single-walled hollow aluminogermanate (ALGE) nano-balls(NBs) and nano-tubes(NTs) have been self-assembled from the ALGE precursors having an Al/Ge ratio of 1.33 using simple pH-control. The hollow ALGE NBs with average monodisperse diameters of 5 nm and chemistry of Al/Ge=1.5~1.6 were formed through structural assembly in the ALGE solution (Al/Ge=1.33) highly basified to pH=13(Na/Al=28~30) and followed by immediate acidification to pH=9. When the basified solution(pH=13) were acidified to pH=4, ALGE S-NTs (Short-fiber nano-tubes) with diameters of 3.3 nm, 15~20 nm in length, and chemistry of Al/Ge=2.6~2.8 were successfully synthesized. Whereas the solution was basified to pH=9, and subsequently acidified to pH=4, L-NTs(Long-fiber nano-tubes) with >100 nm in length were synthesized for the first time. The self-assembly of the hollow NBs, S-NTs, and L-NTs form the ALGE precursors can be explained by the degree of $H^+$-dissociation of the -Ge-OH inner surfaces, which was controlled by amount of $Na^+$ and pH conditions of ALGE precursor solutions. This results indicate that target forms of ALGE nanomaterials can be synthesized by simple pH controls.