Calcium carbonate latter is especially evident in day-to-day life of people who have hard water. Water in aquifers underground can be exposed to levels of CO much higher than atmospheric. As such water percolates through calcium carbonate rock, the CaCO dissolves according to the second trend. When that same water then emerges from the tap, in time it comes into equilibrium with CO levels in the air by outgassing its excess CO. The calcium carbonate becomes less soluble as a result and the excess precipitates as lime scale. This same process is responsible for the formation of stalactites and stalagmites in limestone
Cap carbonate atmosphere, falling as a weak carbonic acid - acid rain. This would weather exposed silicate and carbonate rock, including readily-attacked glacial debris, which would release large amounts of calcium. When washed into the ocean, these precipitate to form distinctively textured layers of carbonate sedimentary rock. A heavily debated cap carbonate appears at the top of the Gaskiers glaciation, believed by many to be global in extent. Cap carbonate Cap carbonates are layers of distinctively textured carbonate rocks which typically form the uppermost layer of sedimentary sequences reflecting major glaciations in the geological record. The rising temperatures, and increased oceanic surface