Inner Shelf Marine Geologic Formations of the South Atlantic Bight: Regulatory Implications and Methods for Project Solutions William Aley, P.G. and Christine Smith Photos courtesy of EPA
Outline Background and Survey Benthic Communities Regional Geology Conclusion
Background and Survey of Fernandina Beach ODMDS Habitat used by recreational divers and fishermen Record review indicated reconnaissance level only screening performed Today screening procedures more rigorous
Results: Resource Map with Bottom Classifications
Benthic Communities Attached organisms: Sponges Gorgonians Tunicates Hard coral (Oculina varicosa only) Fish species: Black Sea Bass Slippery Dick Porgy Cubbyu Belted Sandfish Sheepshead Whitespotted Soapfish Blue Angelfish Tomtate Flounder Red Snapper Gag
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PM / PG Artificial Reef Area Jacksonville, Fl Text Scale: ~ 1 Mile 2
Heading Text Side Scan Mosaic Close-up “potholes”
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Heading Text ICONS Seismic Track Lines NE Florida Study Area
Fernandina (Study Area) St. AugustineDaytona Cape Canaveral NE Florida Offshore Sedimentary Units
NE Florida Generalized Marine Stratigraphy East/West Cross Sections St. Augustine Jacksonville Fernandina
Typical Seismic Profiles South of Study Area
Buried Sinkhole Near Mayport, Fl
Heading Text Study Area 2002 Seismic Survey Northeastern Florida USGS/FGS
Karst Features Observed at Sea Floor Study Area: Offshore Fernandina, Fl
Text Karst Features Observed at Sea Floor Study Area: Offshore Fernandina, Fl
Text Channels Eroded into Shallow Tertiary Sediments Study Area: Offshore Fernandina, Fl
Paleo-River Channels Mapped by FGS Text St. Johns River Mayport, Fl Nassau Sound Fernandina, Fl
Heading Text NE Fl Ledge complexes encountered NOT wave cut platforms /relict shorelines like inner shelf reefs of S Fl. Seismic profiles provide a unique perspective when characterizing inner shelf marine sediments and benthic environments. Sub-bottom sediments of NE Fl characterized by shallow occurrence of lithified, tertiary topographic highs exhibiting several types of karstic dissolution features. Karstic features may be covered by a thin layer of recent sediments or may be directly exposed. Relict braided stream channels have been mapped within these units. Geologic Conclusions
Applications and Future Considerations Applications for disposal area siting, borrow area screening, offshore energy studies, or other similar projects How ephemeral are these features and how does this affect biota? Questions?