On the Experimental Relation between the Chemical and Physical Properties of Weathered Andesite

Abstract

Relation between chemical and physical weathering of andesite has been studied on rock pieces of various stages of weathering. Chemical analysis on the same rocks measured physical properties was performed by atomic absorption spectroscopy method. Results obtained in this study are summarized as follows:
1) As a whole, considerable correlation is recognized among chemical weathering index of SiO2/(Al₂O₃+H₂O⁺) mole-ratio and physical properties, as indicated by Fig. 5 and Fig. 7.
2) Chemical analysis for estimation of chemical weathering indices require the delicacy and skill, and does not expected to be so accurate as physical properties because of inhomogeneity of rocks.
3) If the chemical analysis is limited to weathered rocks which can be prepared a specimen for the compression test, distribution of values of the chemical weathering index is of narrow range, in comparison with its accuracy, than that of physical properties.