) ions from seawater to build shells. When these organisms die, their remains accumulate to form bioclastic limestone. Abiogenic and Microbial
However, this chemical equation does not tell the full story. In the modern ocean, seawater is with respect to calcite and aragonite, yet carbonate does not precipitate spontaneously. Why? The answer lies in kinetic inhibitors —primarily magnesium ions (Mg²⁺) and organic molecules that block crystal nucleation. origin of carbonate sedimentary rocks pdf new
: These biological remains and chemical precipitates pile up in low-energy areas like tidal flats or high-energy reefs, forming thick layers of sediment. ) ions from seawater to build shells
New research suggests that is the missing link. Specific sulfate-reducing bacteria lower the energy barrier for magnesium to incorporate into the crystal lattice, allowing dolomite to form at low temperatures. This "microbial model" is now the leading theory for the origin of massive Precambrian and Paleozoic dolostones. 4. Carbonates and the Global Carbon Cycle In the modern ocean, seawater is with respect