Organic-walled microfossil biostratigraphy and chemostratigraphy of the Ediacaran Volta Basin in Ghana

Agić, Heda; Abu, Mahamuda; Fu, Xuerui; Lin, Ying; Bekker, Andrey

Organic-walled microfossil biostratigraphy and chemostratigraphy of the Ediacaran Volta Basin in Ghana

cb

Files

GEOBIO-D-26-00036 Agic et al.pdf(3.48 MB)

Accepted Version

Supplementary Table 1.xlsx(11.84 KB)

Supplementary Table 2.xlsx(18.16 KB)

Date

2026-09-30

Authors

Agić, Heda

Abu, Mahamuda

Fu, Xuerui

Lin, Ying

Bekker, Andrey

Publisher

Elsevier BV

Published Version

10.1016/j.geobios.2026.09.001

Abstract

A moderately diverse assemblage of Doushantuo-Pertatataka-type (DPA) organic-walled microfossils was recovered for the first time from shales of the Volta Basin of Ghana, West African Craton (WAC). Biostratigraphic and chemostratigraphic (δ13C and δ15N) data for the Kodjari and Pendjari formations were integrated to provide age constraints and establish correlations with other Ediacaran basins. The Kodjari Formation carbonates, developed on a glacial diamictite, have negative carbon isotope values consistent with those for Marinoan cap carbonates. The Pendjari Formation mudstones overlie the Kodjari Formation cap carbonates and have yielded microfossils characteristic of the early Ediacaran, most similar to the assemblages of south-central Australia and Siberia. Carbon and nitrogen isotope values of the Kodjari and Pendjari formations indicate deposition in a shallow-marine, oxygenated environments in a basin with a large nitrate reservoir. The assemblage contains 29 taxa, including diverse acanthomorphs, and it broadly corresponds to the Tanarium–Schizofusa–Variomargosphaeridium Zone established in Australia and the Tanarium conoideum–Hocosphaeridium scaberfacium–Hocosphaeridium anozos Zone in China. However, in Ghana, some taxa diagnostic of different eponymous zones in other regions (Ceratosphaeridium glaberosum, Shizofusa zangwenlongii, Tanarium conoideum) appear together throughout the stratigraphic section. Diversity declines at the top of the succession and DPA taxa are replaced by abundant leiosphaerids and budding and flask-shaped microfossils, which are more characteristic of the post-Shuram anomaly interval. These data establish an early Ediacaran age for the Pendjari Formation and confirm the global distribution and stratigraphic significance of DPA. The Pendjari assemblage further demonstrates a rapid diversification of eukaryotic microbiota following the Marinoan global glaciation.

Keywords

Cap carbonate , Doushantuo-Pertatataka acritarchs , Organic-walled microfossils , Chemostratigraphy , West Africa Craton , Ediacaran

Citation

Agić, H., Abu, M., Fu, X., Lin, Y. and Bekker, A. (2026) 'Organic-walled microfossil biostratigraphy and chemostratigraphy of the Ediacaran Volta Basin in Ghana', Geobios. https://doi.org/10.1016/j.geobios.2026.09.001