Micritisation is the activity of certain
organisms in the
clasts of
carbonate sediments, whereby the organisms retract nutrients from the carbonate. Micritisation is a process that falls under
diagenesis of a sediment.
The organisms can be
algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
,
fungi or
bacteria. These organisms bore small "tunnels" in the original
crystals that the clasts were built from. When the micritisation goes on long enough the process can form ''micritisation envelopes'' around the clast, especially with larger clast (such as shell fragments).
Micritisation disrupts the original crystal structure, chemical composition and structure of the clasts in the sediment.
References
Sedimentology
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