Paleoenvironmental analysis of Ernietta-bearing Ediacaran deposits in southern Namibia

Abstract

Ediacaran fossils from the Nama Group (Kuibis Subgroup) of southern Namibia have a long history of scientific scrutiny, however many of the fossil localities still require investigation from a sedimentary facies and sequence stratigraphic standpoint. Detailed sedimentary analyses utilizing chemostratigraphy and facies-based approaches resulted in five proposed facies and two paleoenvironmental settings that allow for interpretation of the fossiliferous sections as a nearshore to a protected shallow marine paleoenvironment. The classic Ediacaran taxon Ernietta was restricted to the Kliphoek Member of the Nama Group, which limits the stratigraphic range of these organisms to the younger depositional sequence of the Kuibis Subgroup. The paleoenvironment has been interpreted as a mixed carbonate-siliciclastic, protected shallow marine environment at Farm Hansburg, suggesting that these organisms thrived in environments with medium to high flow velocities and periodic clastic sediment supply. Studies that utilize detailed paleoenvironmental reconstructions may aid in constraining phylogenetic affinities of the Ediacara biota by placing reasonable bounds on the local habitat.