The Cryogenian Period (720-635 Ma) is arguably the most pivotal time in Earth history marked by the extraordinary fluctuations in planetary climate regulation of Snowball Earth, changes in surface redox conditions unmatched since the Great Oxidation Event, and the dual biospheric milestones of algae becoming the dominant marine producers and, ultimately, the advent and initial diversification of metazoa. Many conceptual models have been advanced to explain the genesis of these events and gain deeper knowledge of the processes that drove, and the conditions that characterized, such global transformations. Understanding how the Cryogenian Earth system functioned, and identifying the mechanisms that enabled our planet to exit that state, is one of science’s greatest challenges.

The project will recover a total of c. 6 km of core, inclusive of banded iron formation in the Urucum and Chuos formations of Brazil and Namibia, respectively, the Marinoan and Sturtian glaciations and intervening non-glacial strata of the iconic Otavi Group Namibia, and the Mirbat Group strata in Oman that yielded the earliest known animal biomarkers. GRIND-CRY is following GRIND-ECT, which targeted the Ediacaran-Cambrian Transition.

Keywords: Africa, Asia, South America, Namibia, Brazil, Oman, Biosphere evolution, Cryogenian, Earth history, Neoproterozoic