The Petrology of Basanite-Tephrite Intrusions in the Erongo Complex and Implications for a Plume Origin of Cretaceous Alkaline Complexes in Namibia

Basanite intrusions from the Early Cretaceous Erongo complex,Namibia, have compositions consistent with near-primary mantlemelts derived from a depth of at least 100 km. These rocks providea key reference for the mantle component(s) involved in breakup-relatedmagmatism in this region. Initial Sr–Nd–Pb isotoperatios of the Erongo basanites and associated tephrites andphonotephrites (⁸⁷Sr/⁸⁶Sr = 0·70425–0·70465;