Cap carbonates are layers of distinctively textured carbonate rocks (either limestone or dolomite) that occur at the uppermost layer of sedimentary sequences reflecting major glaciations in the geological record.
The progression of late Neoproterozoic glaciations portrayed by substantial δ13C deviations in cap carbonates suggest out of control ice albedo.
[1] Experiments have been performed to see if the massive abiotic carbonate is possible in extreme environments.
Physical stratification results in a strong carbon isotopic gradient in the ocean.
[7] The short-lived change in carbon isotopic composition is the foundation for this theory.