Microscopic

Ooid Layers Brittle and Break with Compaction - Trias (O/37/Tri/Italy)

10x
2.5x
5x
5x
5x
Outstanding feature Radial calcitic ooids that interpenetrate
Folk Classification Bimodal ooidsparite
Dunham Classification Bimodal oograinstone
Common Grains Radial ooids
Sorting Bimodal sorted
Rounding Well rounded
Micritization & envelopes Micritized borings within ooids
Cement & diagenetic fabric Ooids cemented by isopachus bladed rim with equant spar final fill cement
Porosity Dense, none
Depositional Setting High energy shoal
Diagenetic history Interpenetration of ooids and some break

Radial ooid grains that accumulated on high energy shoal coming from two sources, hence bimodality. Note the way the ooids interpentrate under compaction and also note the small fragments of the ooid cortex (layers) floating in the calcite spar cement.


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