Nosy-Be island off the NW coast of Madagascar contains very recent basaltic lava flows from well-preserved cinder cones. Many large crater lakes are found in the central part of the island. A predominance of low-silica foiditic compositions overlie Mesozoic limestones and other sedimentary rocks. The two periods of activity have consisted of initial eruptions of fluid lava flows from the W side of the massif, followed by the construction of numerous cinder cones on the W plain. Little is known about the age of the volcanic field, and the only K-Ar dates are Tertiary in age, but the volcanics were mapped as Recent (Besairie, 1973).