ABSTRACT

Four types of multivariate procedures (principal components analysis (PCA), factor analysis (FA), cluster analysis and multiple regression analysis (MR)) were applied to find the relationship between volatile contents and genesis of Japanese volcanic rocks. Twelve major elements and seven volatile minor elements were considered on 44 rock samples obtained from various areas of Japan. The variation in the data was demonstrated by 5 components and 5 common factors in PCA and FA, respectively. The first factor implies similar behavior among the major elements; the second factor represents the contribution of seawater to magma genesis; the third factor corresponds to the contribution of the mantle component; the fourth factor suggests separation of sulfide phase from silicate phase; and the fifth factor shows the contribution of sedimentary materials to magma genesis.