Iron-rich carbonate tidal deposits, Angepena Formation, South Australia: A redox-stratified Cryogenian basin

Abstract

The Cryogenian Angepena Formation (ca. 650 Ma) of South Australia records deposition in a peritidal environment equivalent to, and landward of the Balcanoona reef complex, and offers valuable insights into shallow marine chemistry during the nonglacial interlude between two global ice ages. The sedimentary facies comprise an iron-rich marine red bed succession and include red mudcracked dolomitic shales, tepee dolostone, crossbedded intraclastic ooid grainstone, and tepee-related sheet cavities with marine cements. These facies are interpreted to have been deposited in a Cryogenian tidal flat to subtidal setting that is laterally equivalent to the reefal and back reef environments of the Bal..