Pelloid Ghosts - Cemented Capillary crust of Algal Mat (Mic/2/Hol/Bah)
 5x
|
 2.5x
|
| Outstanding feature |
Micrite peloids, with dispersed fine grained thin bioclastic fragments & fenestral voids |
| Folk Classification |
Fossiliferous pelmicrite |
| Dunham Classification |
Pellet wackestone |
| Common Grains |
Pelloids and fine grain skeletal grains |
| Sorting |
Moderately sorted grains in micrite |
| Rounding |
Local rounding |
| Micritization & envelopes |
None to be seen. Probably obscured by micrite |
| Cement & diagenetic fabric |
Micrite |
| Porosity |
10% in fenestral voids |
| Depositional Setting |
Low energy supratidal capillary crust |
| Diagenetic history |
Cemented by carbonate precipitated at the top of the capillary zone |
This is a fairly typical supratidal crust developed through the cementation of the surface sediments by micrite. These sediments include pellets and bioclastic material. They accumulated in a low energy supratidal restricted setting where evaporation of the water in the capillary zone has caused the cementation..
Thursday, November 11, 2021