Authigenesis

Authigenesis is the process whereby a mineral or sedimentary rock deposit is generated where it is found or observed.

The authigenesis process is driven by particles of sediment that are not in thermodynamic equilibrium with the conditions surrounding it.

This often occurs in the ocean where changing conditions due to biological processes is common.

For example, the area of deposition must be above the carbonate compensation depth or the pore waters must be sufficiently saturated due to dissolution of other grains for calcite to precipitate.

This causes compaction and cementation to occur and decreases porosity farther, changing the control on the authigenesis process from fluid composition to temperature.