言語 |
英語
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著者 |
S.S.ABE
G.O.OYEDIRAN
S.YAMAMOTO
T.HONNA
T.WAKATSUKI
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内容記述(抄録等) | The particle-size distribution and mineralogical composition of the clay (< 2 μm) and fine-sand (0.25–0.10 mm) fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigated to provide basic information on soil-forming processes and agricultural potentials. These soils were silty or clayey, deriving from Cretaceous or Tertiary shale materials. The particle-size distribution and its computation on a clay-free basis revealed relatively remarkable lithologic breaks in a couple of pedons. The effect of lithologic discontinuities on soil mineralogical composition was not, however, conspicuous. Petrographic investigation revealed that quartz predominantly comprised the fine-sand fraction in the soils at both study sites. Nevertheless, the clay mineralogical composition of the soils was a mixture of kaolinite, irregularly interstratified smectite-illite intergrades (S/I), hydroxyl-Al interlayered 2:1 type clays (HICs), vermiculite, smectite, halloysite and illite along with fine-sized quartz in Abakaliki. The soils of Bende predominantly contained smectite, which was partially interlayered with hydroxyl-Al and kaolinite. It is suggested that seasonal floodwater has slowed the disintegration of weatherable clay minerals inherited from the shale, while quartz originating from the sandstone is predominant in the fine-sand fraction. Additionally, a possible soil-forming process observed at the both study sites was ferrolysis, which was indicated by a clear decreasing pattern of HICs downward in the soil profiles. The entry of S/I and vertical distribution patterns for a couple of clay minerals in the pedon suggested that the soils in Abakaliki have developed under the significant influence of aeolian dust delivered by the Harmattan. The findings might describe a site-specific deposition pattern of Harmattan dusts as well as hydromorphic soil-forming processes in the wetlands of the inland valleys.
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主題 | aeolian dust
ferrolysis
hydromorphic soil
hydroxyl-Al interlayered 2
1 type clays
Southeast Nigeria
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掲載誌名 |
Pedosphere
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巻 | 19
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号 | 4
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開始ページ | 505
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終了ページ | 514
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ISSN | 1002-0160
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発行日 | 2009-08
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DOI | |
出版者 | Elsevier Ltd
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資料タイプ |
学術雑誌論文
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ファイル形式 |
PDF
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権利関係 | Copyright © 2009 Soil Science Society of China. Published by Elsevier Ltd All rights reserved.
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著者版/出版社版 |
出版社版
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業績ID | e9268
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部局 |
生物資源科学部
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備考 | Abe, S. S., Oyediran, G. O., Masunaga, T., Yamamoto, S., Honna, T. and Wakatsuki, T. 2009. Soil development and fertility characteristics of inland valleys in the rain forest zone of Nigeria: Mineralogical composition and particle-size distribution. Pedosphere. 19(4): 505–514.
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