In view of the geological condition of soft metamorphic rock slope in Jinpen Reservoir

the influence of clay minerals on soft metamorphic rock slope is systemat ically studied through a careful analysis of the main properties and formation mechanisms of clay minerals

from micro to macro levels. Results show that soft metamorphic rock can easily produce clay minerals because of such characteristics as complex origin

various mineral composition

and weak water stability. However

clay minerals in rock may bring about marked changes in some properties of parent minerals

mineral aggregation or rock and promote rock to evolve toward loose medium. Moreover

the illuviation of clay minerals in macro discontinuities and the formation of mudded intercalation will cause the strength of discont inuities and rock mass to decrease. To sum up

clay minerals may accelerate deformation of slopes and their contribution to slope evolution and failure is notable.