U-Pb and Pb-Pb ages of the Naauwpoort rhyolite, Kawakeup leptite and Okongava Diorite: implications for the onset of rifting and of orogenesis in the Damara belt, Namibia
The Naauwpoort quartz porphyry formed during local synsedimentary volcanism towards the end of the initial rifting phase in the central Damara belt of Namibia. SHRIMP U-Pb analysis of zircons from the Naauwpoort rhyolite dates this volcanism at 752±7 Ma whilst evaporation Pb-Pb analysis on the Kawakeup metarhyolite, a correlative unit from the southern Swakop terrane, suggests a minimum date of ~705 Ma. The pre-D2 Okongava Diorite provides a SHRIMP zircon date of 558±5 Ma which is much younger than previously thought. Inherited zircon cores in the diorite document the presence of ~2 Ga zircons in the source origin of the diorite.
Communications of the Geological Survey of Namibia
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U_Pb and Pb_Pb ages of the Naauwpoort rhyolite_Kawakeup leptite and Okongava Diorite.pdf | 1.43 MB |