Modern carbonate deposition is restricted to warm (18–30°C), clear, shallow, oligotrophic waters. However, ancient examples include deep-sea chalks.
The fundamental prerequisite for carbonate formation is the supersaturation of seawater with respect to calcium carbonate. This is governed by the solubility product ($K_sp$) and the activity of ions in solution. origin of carbonate sedimentary rocks pdf extra quality
To help you get the most out of this topic, could you tell me: g., Paleozoic vs. Cenozoic carbonates)? oligotrophic waters. However