Micrite Cement with Halimeda, Echinoid Overgrowths & Forams (Mic/3/Pl/Fla)
2.5x cross nicols
|
5x
|
5x cross nicols
|
2.5x
|
2.5x cross nicols
|
2.5x
|
Outstanding feature |
Foraminifera, halimeda, vermiculid gastropods cemented by micrite |
Folk Classification |
Poorly washed biomicrite |
Dunham Classification |
Bioclastic wackestone |
Common Grains |
Foraminifera, halimeda and vermiculid gastropods |
Sorting |
Poor |
Rounding |
Little |
Micritization & envelopes |
Some alteration of the margins of bioclasts |
Cement & diagenetic fabric |
Micrite |
Porosity |
25% interparticle and intraparticle |
Depositional Setting |
Low energy proteced area in reef |
Diagenetic history |
Early disolution of some of aragonite, eg Halimdeda. |
This fabric is typical of a cemented reef fabric. The high energy grains accumulated in a very low energy setting within the reefs which was exposed to marine waters and then freshwater diagenesis.
Thursday, November 11, 2021