Some Factors in the Diagenesis of Carbonates

In carbonate diagenesis V we deal usually with a combination of low supersaturation and absence of mechanical agitation. Homogeneous nucleation will certainly not occur. The important factors to be investigated are heterogeneous nucleation and rates of growth and dissolution of crystals. 

The effects of trace concentrations of dissolved organic matter and of orthophosphates (Berner and Morse, 1974) and polyphosphates as crystal poisons (e.g., inhibiting the spread of monomolecular steps on the crystal surface by becoming 

V Diagenesis refers to the sum total of processes that bring about charges in sediment or sedimentary rock subsequent to deposition in water. The processes may be physical or chemical or biological in nature and may occur at any time (Berner, 1986). 

Another category of inhibition may be exerted by cations or anions that become adsorbed on active growth sites. Well-hydrated Mg2+ interferes with the formation of caicite, apatite, and many other minerals. 

Finally, ions that become adsorbed on the surface of nuclei or crystallites may become incorporated into the growing crystals, that is, solid solutions are formed. These solid solutions may be more soluble than the pure solid phases the inhibition may then be due to an reduction in the degree of supersaturation. 

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