Precise SHRIMP U-Pb zircon age constraints on the lower Waterberg and Soutpansberg Groups, South Africa

Abstract

Erosional remnants of Paleoproterozoic red bed successions such as the Olifantshoek, Soutpansberg, Waterberg and Palapye Groups cover an extensive area of the Kaapvaal Craton. Depositional ages of these successions have been ill-defined and their lateral correlation a subject of controversial debate. We report precise zircon SHRIMP U-Pb ages of 2054 ± 4 and 2051 ± 8 Ma for quartz porphyry lavas stratigraphically near the base of the Waterberg Group from the Lower Swaershoek and correlative Rust de Winter Formations. The Entabeni Granite, erosively overlain by the Soutpansberg Group, yields a precise zircon SHRIMP age of 2021 ± 5 Ma. These ages indicate that at least part of the Waterberg Group is older than the Soutpansberg Group. In addition, the lower part of the Waterberg Group was deposited immediately after intrusion of the Bushveld Complex and may be tectonically related to the complex.