Introduction: Initial investigations of a Neoarchean shelf margin-basin transition (Transvaal Supergroup, South Africa)

The late Archean to earliest Paleoproterozoic Transvaal Supergroup preserves both thick platform carbonates and basinal successions rich in iron formation. Two new drill cores, sponsored by the Agouron Institute, document the platform-basin transition, thus facilitating the reconstruction of both late Archean basin development and biogeochemical processes at play just before the Great Oxidation Event. Interpreted in light of previous outcrop and subsurface studies, the new cores provide an unusually detailed framework of time and environment for sedimentological, palemagnetic, and geochemical analyses. The papers in this special issue constitute the first fruits of research on the Agouron cores, but undoubtedly not the last.