Ooids ( O/2/Hol/Bah )
2.5x
|
2.5x cross nicols
|
5x
|
5x cross nicols
|
10x
|
10x
|
Outstanding feature | High energy concentric aragonite ooids |
Folk Classification | Well sorted ooids |
Dunham Classification | Well sorted ooids |
Common Grains | Ooids |
Sorting | Well sorted |
Rounding | Well rounded |
Micritization & envelopes | A few coated grains |
Cement & diagenetic fabric | Uncemented |
Porosity | Unconsolidated sediment, highly porous |
Depositional Setting | High energy shoal |
Diagenetic history | Precipitation of aragonite on pellets |
Striking high energy concentric aragonite ooid grains collected where they are forming in the vicinity of Joulters Cays on the NE margin of the Great Bahamas Bank. Note the empty pores within the ooids that are the product of dissolution induced by boring cyanobacteria (blue-green algae).
Thursday, November 11, 2021