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http://dx.doi.org/10.9720/kseg.2011.21.4.381

Characterization of Microtextures formed by Chemical Weathering in Crystalline Rocks and Implications for Rock Mechanics  

Choo, Chang-Oh (Dept. of Earth and Environmental Sciences, Andong National University)
Jeong, Gyo-Cheol (Dept. of Earth and Environmental Sciences, Andong National University)
Publication Information
The Journal of Engineering Geology / v.21, no.4, 2011 , pp. 381-391 More about this Journal
Abstract
Weathering can reduce rock strength and eventually affect the structural stability of a rock mass, which is important in the field of engineering geology. Several methods have been developed to evaluate the degree of weathering, including the chemical weathering index. In this study, we analyzed the weathering degree and characteristics of microtextures and pores in crystalline rocks (gneiss and granites) based on petrographic observations, the chemical weathering index, mineralogy by XRD, microtextural analysis by SEM/EDS, measurements of pore size and surface area by the BET method, and microporosity by X-ray CT. The formation of secondary minerals and microtexture in gneiss and granitic rocks are assumed to be affected by complex processes such as dissolution, precipitation, and fracturing. Hence, it is clear that some chemical weathering indices that are based solely on whole-rock chemistry (e.g., CIA and CWI) are unable to provide reliable assessments of the degree of weathering. Great care is needed to evaluate the degree of chemical weathering, including an understanding of the mineralogy and microtexture of the rock mass, as well as the characteristics of micropores.
Keywords
weathering process; SEM; BET; X-ray CT; microtexture; micropore;
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Times Cited By KSCI : 4  (Citation Analysis)
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