Study of andesite weathering in northern Taiwan using micromorphological approaches
Journal
Taiwan Journal of Forest Science
Journal Volume
13
Journal Volume
13
Journal Issue
4
Journal Issue
4
Pages
259-269
Start Page
259
End Page
269
ISSN
10264469
Date Issued
1998-12-01
Author(s)
Abstract
Very limited information has been reported concerning andesite weathering. This study was conducted to gain, through a micromorphological approach, information on the nature of andesite weathering under the prevailing perhumid subtropical climate of northern Taiwan. An attempt was also made to interpret the pedological and ecological implications of the information gained. Results show that andesite weathering in the study area is relatively rapid. The microstructure of the rock as well as the stahility of the mineral components appear to greatly influence the progress of weathering. In agreement with published literature, amphibole and pyroxene appeared to dissolve ahead of feldspar. Four approximate stages of the weathering process were approached based on the micromorphological study. Dissolution of small amphibole and pyroxene grains result in the accumulation of Fe and Mn oxides. Fe and Mn coatings tend to form along the boundaries of the weathered grains. Substantial amounts of Fe oxides are assimilated into the matrix near the site of dissolution. The porous nature of the saprolite is directly related to the high porosity of Andisols in this study area.
Subjects
Andesite
Andisols
Ecology
Micromorphology
Weathering
SDGs
Publisher
農業部林業試驗所
Type
journal article