Abstract:
In the model of purely biogenic mechanism, organisms make up skeletons of aragonite and calcite (including the high-magnesian variety), which are transferred to sediments after their death to provide the basis of carbonate rock. The biochemogenic mechanism is connected with the activity of photosynthesizing organisms, which consume the water-dissolved carbon dioxide, increase pH of the medium, and disturb the carbonate equilibrium, leading to the decomposition of dissolved bicarbonates and precipitation of insoluble carbonates.
