Mount Lowe Intrusive Suite

Mount Lowe intrusive series is a geologic formation occurring in the San Gabriel Mountains in southern California. It is composed of layered pluton exposed over a large area in western San Gabriel Mountains and northeastern Soledad Basin. The formation varies from hornblende diorite and quartz diorite in the lowest part to albite-rich granite and syenite in the upper part. Within the formation large phenocrysts of hornblende, orthoclase and garnet contribute to distinctive appearance.^[1]

The formation was first named by William J. Miller as "Mount Lowe Granodiorite" in 1934.^[2]