My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in SSSAJ

  1. Vol. 54 No. 4, p. 1043-1048
     
    Received: July 5, 1989
    Published: July, 1990


    * Corresponding author(s):
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2136/sssaj1990.03615995005400040019x

Alkali Basalt Gravel Weathering in Quaternary Allier River Terraces, Limagne, France

  1. E. Veldkamp,
  2. A. G. Jongmans ,
  3. T. C. Feijtel,
  4. A. Veldkamp and
  5. N. van Breeman
  1. Dep. of Soil Science and Geology, Agric. Univ. Wageningen, P.O. Box 37, 6700 AA Wageningen, the Netherlands

Abstract

Abstract

Weathering of alkali basalt pebbles was studied in three Quaternary Allier terraces of different ages. The isovolumetric method and Ti-constant method were applied to quantify compositional changes due to weathering. Bulk density of fresh gravel in the younger terraces (Weichselien and Holocene) was adequately estimated from geochemical data by a multiple linear regression model (R2 = 0.81**, significant at P = 0.01). Since no chemical and micromorphological differences could be demonstrated between fresh gravel and the unweathered cores of partly weathered gravel, the regression model was also applied to calculate the bulk density of the cores of partly weathered pebbles in the oider terraces. The decrease in bulk density of the rind, compared with that of the core, was used as a measure of weathering intensity. The chemical composition of the weathering rind revealed a relative increase in the contents of Ti, Al, Fe, and Mn and a decrease of K, Na, Ca, and Si. Changes were estimated considering Ti essentially immobile. Except for Fe and Mn, all elements tended to decrease in the rind. The relative elemental mobilities were as follows:

K > Na > Si > Mg > Ca > P > Al > Ti

No relationship was found between weathering intensity and the age of the two oldest terraces or sampling depth. Differences in weathering intensity are predominantly a function of chemical (= mineralogical) composition of the alkali basalt pebbles.

Contribution of the Dep. of Soil Science and Geology, Agric. Univ. Wageningen.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © . Soil Science Society of America