Abstract
The Mikabu Greenstone Belt is characterized by many creeping landslides with comparatively small slip angles. Landslide distribution in this belt corresponds to the distribution of schistose greenstone and obscures in massive greenstone. Schistose greenstone has well-developped cracks and cleavage, which cause an easy ground water permeation. Also, schistose greenstone being mainly composed of actinolite and chlorite can be easily hydrated. Weathering process of schistose greenstone begins with dissolution of Ca2+ at first, and formation of smectite then takes place after dissolution of Mg2+ from actinolite and chlorite. Thus, the physicochemical weathering processes seems to have progressively changed the petromineralogic properties of the rock.
