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formation Mechanisms of 1:1 Clay Minerals by Biotite Weathering In a Granitic Gneiss  

이석훈 (한국기초과학지원연구원 중앙분석기기부)
김수진 (서울대학교 지구환경과학부)
Publication Information
Journal of the Mineralogical Society of Korea / v.15, no.3, 2002 , pp. 221-230 More about this Journal
Abstract
Weathering of biotite shows a biotite-vermiculite-kaolinite sequence at the early stage, but presents biotite-kaolinite sequence without a significant intermediate phase (vermiculite) at the late stage from the weathering profile of the granitic gneiss. Secondary 1:1 phyllosilicates are kaolinite and halloysite which show different weathering textures originated by a different formation mechanism. Kaolinitization began from the edges of biotite and propagated toward the interior of grain along a multilayered front. $10 \AA$ layers of biotite are interleaving with $7\AA$ layers of kaolinite and c-axis of two phases is consistent. Kaolinite pseudomorph of biotite is isovolumetric, compared to the biotite boundary and includes many band-like porosities parallel to the cleavage. Platy kaolinite formed by 1:1 layer fur layer replacement of biotite. Halloysitization proceeded outward from the grain edges which were foliated as fine flakes and bent at the right angle for cleavage Halloysites were extensively fanning out and greatly increased the volume of grain. This indicated that halloysite tubes were formed by epitaxial overgrowth on the surface of biotite with import of Si and Al from the external solution by dissolution of plagioclase. These halloysites have abnormally high Fe content ( ~11%).
Keywords
kaolinite; halloysite; topotaxial replacement; porosity; epitaxial overgrowth;
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  • Reference
1 Banfield, J.F. and Eggleton, R. (1988) Transmission electron microscope study of biotite weathering, Clay and Clay Minerals, 36, 47-60.
2 Eswaran, II. and Bin, W.C. (1978) A study of a deep weathering profile on granite in penisular Malaysia. II: Mineralogy of the clay, silt and sand fractions, Soil Sci. Soc. Am. L 4, 149-153.
3 Gilkes, R.J. and Suddhiprakarn, A. (1979b) Biotite alteration in deeply weathered granite. II. The oriented growth of secondary minerals. Clay and Clay Minerals. 27, 349-360.
4 Samotoin, N.D., Norikov, V.M., and Magazina, L,,O.(1987) Paragenesis of secondary clavs in a bauxitebearing granite weathering zone. Inter, Geol. Rev. V. H. Winston & Sons, 1215-1227.
5 Wilson, M..J. (1970) A study of weathering in soil derived from a biotite- hornblende rock. Clay Mineral 8. 291-303.
6 Jeong, G.Y. (1998) Vermicular kaolinite cpitactic on primary phyllosilicatcs in the weathering profiles of anorthosite. Clays Clay Miner., 46, 509-520.
7 Harris, W.G., Zelazny, L.W., Baker, .I.C.. and Martens, D.C. (1985a) Biotite Kaolinization in Virgina Piedmont Soils: I. Extent. profile Trends, and Grain Morphological Effects, Soil Sci. Soc.Am. .J. 49, 1290-1297.
8 Churchman, G.J., Whitton, .I.S., and Claridge, F.G.C.,(1984) Intercalation method using formamide for differentiating halloysite from kaolinite. Clays and Clay Minerals, 32, 241- 248.
9 Kittrick, .J.A. (1973) Mica-derived vermiculites as unstable intermediate. Clays Clay Miner., 21, 479488.
10 Rebertus, R.A., Weed, S.B., and Buol, S.W. (1986) Transformation of biotite to kaolinite during saprolite-soil weathering, Soil Sci. Soc. Am. .I. 50.810-819.
11 Harris. W.G., Zelazny, L.W., Baker, .I.C., and Martens, D. C. (1985b) Biotite Kaolinization in Virgina Piedmont Soils: II. Zonation in Single Grains, Soil Sci. Soc. Am. .J. 49, 1297-1302.
12 Lee, S.H. (1999) Electron microscopic study on the weathering of the granitic gneiss in the Yoogoo area, Korea. PhD thesis in Seoul National Univcristy,200p.
13 Wilson, M.J. (1966) The weathering of biotite in some Abcrdccnshirc soils, Mineral Mag., 35, 1080-1093.
14 Velbel M.A. (1989) Weathering of hornblende to ferruguinous products by a dissolution-precipitation mechanism: Petrography and stoichiometry. Clay and Clay Minerals, 37, 515-524.
15 Dong, H., Peacor, D.R., and Murphy, s.r. (1998) TEM srudy of progressive alteration of igneous biotite to kaolinite throughout a weathered soil profile. Gcochim, Cosmochim., 62, 1881-1888.
16 Eswaran, II. and l lcng, Y.Y. (1976) The weathering of biotite in a profile on gneiss in Malysia, Gcodcrrna, 16. 9-20.
17 Novikoff, A., Tsawlossou, G., Gac, .J.Y., Bourgeat, F., and Tardy, Y. (1972) Weathering of biotitcs in temperate, tropical and equatorial countries, Sci. Geol. Bnll., 25, 287-306.
18 Stoch, L. and Sikora, W. (1976) Transformation of micas in the process of kaolinization of granite and gneisses. Clays Clay Mincr., 24, 156-162.
19 이석훈, 김수진 (2000) 유구지역 화강암질 편마암의 풍롸작용에 의한 광물 조성의 변화, 한국광물학회지, 13, 121-137.
20 Churchman, C.J. and Gilks, R.J. (1989) Recognition of intermediates in the possible transformation of halloysitc to kaolinite in weathering profiles, Clay Minerals, 24, 579-590.
21 Gilkes, R.J. and Suddhiprakarn, A. (1979a) Biotite alteration in deeply weathered granite. I. Morphological, mineralogical, and chemical porperties, Clay and Clay Minerals. 27, 349-360.