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Shallow Marine Carbonate Environments. "Carbonate sediments are born not made". Subtidal Carbonate Factory. Shallow (< 20m), subtidal, well circulated, marine shelf environment. Carbonate (mostly biogenic) sediment is transported both shoreward and basinward. Controls on Carbonate Facies.
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Shallow Marine Carbonate Environments "Carbonate sediments are born not made"
SubtidalCarbonate Factory • Shallow (< 20m), subtidal, well circulated, marine shelf environment. • Carbonate (mostly biogenic) sediment is transported both shoreward and basinward.
Controls on Carbonate Facies • Environmental conditions • Depth • Salinity • Temperature • Oxygenation • Faunal Succession • Currents/sorting
Carbonate Platforms/Depositional Systems • Ramp • Rimmed Shelf • Epieric Platform • Isolated Platform
Common Carbonate Platforms Types Carbonate Ramp Rimmed Carbonate Platform
Generic Rimmed Carbonate Platform Model "X", "Y", "Z" facies • Open shelf/basin • Re-sedimented, storm wave reworked carbonate turbidites and pelagic mudstone/wackestone • Slope facies breccias • Mixed redeposited shallow marine and pelagicfauna
Generic Rimmed Carbonate Platform Model: "X“ facies • Outer Shelf ("Reefs"): high energy, wave washed barrier; "X" • biohermal "reef" and associated fragmental carbonate sands • carbonate grainstone/packstone and boundstone facies • algae, corals, sponges, stromataporoids, bryozoans, rudists
Middle Shelf ("Subtidal Shelf Carbonates"): low energy, subtidal, back barrier; "carbonate factory"; "Y" abundant biogenic carbonate mud production: good circulation, little temperature variation, abundant bioturbation patch reefs and grainstone shoals carbonate wackestone/ mudstone facies; peletal muds and "grapestone" brachiopods,pelecypods, gastropods, crinoids, echinoderms Generic Rimmed Carbonate Platform Model: "Y“ facies
Inner shelf ("Peritidal Environments"): intertidal-supratidal with episodic storm-induced flooding; "Z" extremes of temperature and salinity; hypo- to hypersaline (climate determined): highly variable physical environment stromatolites and cryptalgal laminations common: algal mudstone algal mats, dessication features, rip-up clasts and early lithification, oncolites, fenestrae, primary dolomite and evaporite deposits Generic Rimmed Carbonate Platform Model: "Z" facies
Carbonate Facies • South Florida Bahamas Platform
Environmental Concerns in Carbonate Dominated Coasts • Fresh water pollution • Temperature pollution • Sewage/chemical pollution