Conventional K-AR and AR-40/AR-39 ages of the Miocene submarine rocks of the Cape Verde Islands

Conventional K-Ar and argon-40/argon=39 stepwise heating age determinations have been performed on eight whole rock basaltic samples from four sites on the island of Maio in the Cape Verde Group of Islands. Thin sections of these samples collected from the Mesozoic igneous rock complex indicate that they are unlike the overlying sequence of Pliocene basaltic volcanics and are known to be of Miocene ages. Results of this work confirm the Miocene ages and indicate that most probably these young ages were due to later metamorphic events that reoccurred at the four different sites at various times between 8 and 15 Ma ago