Cap carbonate

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. 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. Cap carbonates are found on most continents. They are typically 3–30 meters thick, laminated structures. They are depleted in 13C compared to other carbonates. The progression of late Neoproterozoic glaciations portrayed by substantial δ13C deviations in cap carbonates suggest out of control ice albedo.