thumbnail

Experimental chemical weathering of various bedrock types at different pH-values. 1. Sandstone and granite

Chemical Geology

By:
, ,
DOI: 10.1016/0009-2541(85)90149-4

Links

Abstract

Experimental chemical weathering of the so-called Old Rag Granite and Massanutten Sandstone, Virginia, U.S.A., has produced a comparison with the natural environment, and prediction of the effect of acid precipitation. The experimental results of the release of elements, dissolution of minerals, total rock weathered and the degree of weathering as function of volume of leachate were plotted. These data were compared with the natural environment. The use of the plots to predict the effect of high levels of rain acidity on weathering of these rocks is demonstrated. A nonexpandable 14-A?? clay was developed from the alteration of biotite during the experimental chemical weathering of the granite at pH 4. This interstratified Al(OH)-mica clay resembles those of the soil developed on the granite and sandstone. Hydroxy-Al may be precipitating between the mica interlayers and producing a 14-A?? spacing. Development of this clay by chemical alteration of biotite may change the current hypotheses about its origin in the soils of northeastern U.S.A. While Al-hydroxide seems to regulate Al concentrations in stream waters at the present level of rain acidity, it was found that at lower pH and in the presence of high sulfate concentrations, Al solubility may be controlled by Al-sulfate phase(s). ?? 1985.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Experimental chemical weathering of various bedrock types at different pH-values. 1. Sandstone and granite
Series title:
Chemical Geology
DOI:
10.1016/0009-2541(85)90149-4
Volume
49
Issue:
1-3
Year Published:
1985
Language:
English
Publisher:
Elsevier
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
87
Last page:
113
Number of Pages:
27