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言語
英語
著者
S.S.ABE
G.O.OYEDIRAN
S.YAMAMOTO
T.HONNA
T.WAKATSUKI
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.
主題
aeolian dust
ferrolysis
hydromorphic soil
hydroxyl-Al interlayered 2
1 type clays
Southeast Nigeria
掲載誌名
Pedosphere
19
4
開始ページ
505
終了ページ
514
ISSN
1002-0160
発行日
2009-08
DOI
出版者
Elsevier Ltd
資料タイプ
学術雑誌論文
ファイル形式
PDF
権利関係
Copyright © 2009 Soil Science Society of China. Published by Elsevier Ltd All rights reserved.
著者版/出版社版
出版社版
業績ID
e9268
部局
生物資源科学部
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.