全北 全州地域 花崗岩 및 郎山地域 花崗岩의 風化에 따른 化學組成의 變化와 主要元素의 相對的移動

Variation of chemical composition and relative migration of major elements in the weathering of Jeon-ju granite and Rang-san granite

Weathering of granites has a geochemical role of great significance, because of their abundance and because of chemical instability near the surface of the earth, which is more pronounced than in most other rocks. On the other hand the granites are tectonically fragile and “react” to deformation with marked facility, giving rise to a whole gamut of deformed rocks. Therefore, the writer has studied on the weathering of granitic rocks at of Iri city and Jeonju city Jeollabukdo, Korea. The fresh and weathered rocks were used as material for the investigation. The results obtained by chemical analysis and observation are as follows. 1) The order of mobility in major elements was Ca, Na and K＜Si＜Mg＜Fe and Al. 2) The increasing phenomena of H₂O was observed clearly and late stages of weathering processes. 3) The early stage of weathering is commenced by physical weathering and followed by chemical weathering. 4) The ratio of FeO/. Fe₂O₃, FeO/MgO, and SiO₂/Al₂O₃ decreased uniformly from early to late stage of weathering processes. 5) It was proved that weathering potential of granite was larger than that of basaltic rocks.