1. Carbonate Ramp Facies

2. Carbonate Ramps
Consistent shallow gradient from shoreline to basin (some may be distally steepened), somewhat analogous to siliciclastic shelf
Highest Energy
Lowest Energy

3. Carbonate Ramp Environments
Deep ramp
Mid ramp
Inner ramp
Peritidal
Offshore
Deep Subtidal
Shallow Subtidal
Offshore-
Transition
Offshore
Shoreface
Siliciclastic Equivalents

4. Thin packstone “tempestites” in lime mudstone (or siliciclastic mud)
May be normally graded or contain HCS; gutter casts/sole marks on base
Deep Subtidal, Offshore
Offshore
Deep Subtidal

5. Large subaqueous dunes, generating large-scale cross-bedding
Shoals (ooids or skeletal) are much more common than in clastic settings
Large subaqueous dunes, generating large-scale cross-bedding
Shallow Subtidal

6. Other sedimentary structures and facies may be similar to siliciclastics (wave ripples, SCS, low-angle parallel beach laminations, etc.)
Swaley cross-stratification (SCS)
Beach deposits
Low-angle beds with hardgrounds

7. Peritidal Carbonates

8. Typical facies: light gray or light brown limestone/dolostone with
Crinkly or wavy lamination from microbial mats
Fenestrae: mm-sized voids (sometimes filled by calcite spar) formed by trapped gas bubbles or beneath microbial mats

9. Polygonal desiccation cracks (wedge shaped in side view) formed by drying and thermal contraction during tidal cycle

10. Tepee Structures in high intertidal/supratidal zone

11. Continued cycles of desiccation disrupt tepees, forming flat pebble conglomerates

12. CAUTION: flat-pebble conglomerates occur in any place where thin layers of limestone are subject to seafloor lithification (e.g., also in wave-influenced beaches and in many subtidal environments before the Ordovician)

13. (or pseudomorphs after gypsum)
Supratidal sabkha environments (arid supratidal flats) characterized by evaporite mineral (gypsum, anhydrite, rarely halite) formation
Gypsum laths
(or pseudomorphs after gypsum)
Anhydrite nodules

14. Classic carbonate platform environments
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Classic carbonate platform environments
Carbonate Ramp