Age, palaeomagnetism and chemistry of melilite basalts in the Southern Cape, South Africa

Summary Post-Karroo melilite basalts intrude Cretaceous and older sedimentary units in the Cape Province, South Africa. K-Ar ages determined from 4 occurrences range from 63–75 Ma b.p. (Late Cretaceous to earliest Tertiary) and are significantly older than alkaline intrusions to the 5, on the Alphard Bank. These igneous intrusions may be part of a linear trend that connects young oceanic volcanism at Bouvet Island with Cretaceous kimberlitic activity in southern Africa. This lineament nearly parallels the Walvis Ridge and a hot spot model for its origin is examined.

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