Radial Calcitic Ooids - Cerebroid Disolution of Surface by Algae (O/27/)
| Outstanding feature |
Radial cerebroid ooids |
| Folk Classification |
Well sorted oosparite |
| Dunham Classification |
Well sorted oograinstone |
| Common Grains |
Cerebroid ooids |
| Sorting |
Well sorted |
| Rounding |
Well rounded |
| Micritization & envelopes |
Some micritized borings into radial fabric |
| Cement & diagenetic fabric |
Thin equant rims and final spar fill |
| Porosity |
Intercrystalline |
| Depositional Setting |
High energy but restricted shoal |
| Diagenetic history |
Potetially a marine rim replace by equant calcite with a final equant spar fill |
Well preserved cerebroid calcitic ooid grains that accumulated on restricted shoals. Intitial isopachus rim cements may be after marine rims. Later these rimmed cements have undergone alteration to calcite with freshwater leaching. The final void fill cementation was by low magnesian calcite spar. The carbonate of the cement was probably derived from earlier aragonitic material.
Thursday, November 11, 2021