April 20, 2010—BP’s Deepwater Horizon deepwater drilling platform exploded; 11 dead, 17 injured, 98 escaped uninjured; well capped July 25; bottom kill Sep 19; What happened? Major investigations ongoing… Gulf of Mexico one of largest oil/gas provinces in world; 3 megaprovinces

stillstand rise event total time years during rise event m of rise intervals span m/yr mm/yr SL3 to SL4 R3 220 110 6 0.0545 55 SL2 to SL3 R2 500 250 9 0.0360 36 There are siliciclastic low, sea level indicators on the NW Florida shelf--Early period of delta deposition on outer shelf— formed when SL ~40-70 m water depth—how to date? Paleoshorelines Enter the deep coral reef at Pulley Ridge—an accidental discovery. Florida Middle Ground Multibeam bathymetric recurved data indicates that spits southern Pulley Ridge is a drowned barrier island!

This provided the hard prograding beach tidal ridges substrate on which the inlets corals could attach tidal themselves. inlet

drumstick barrier island geomorphology Agaricid coral plates— like shingles on a roof.

Also, Agaricia undata; A. lamarki; Leptoceris cucullata; Montastraea cavernosa; A. fragilis; Oculina sp.; Madracis mirabilis;Madracis decactis. Deepwater hard substrates supporting benthic communities formed by erosion due to strong currents. Paleo-sealevel history controls distribution of hard substrates which support important benthic communities. Need high resolution seafloor imaging and sampling to understand distribution of paleoshorelines and other substrates. DeSoto Canyon key geologic boundary between two different sedimentary depositional regimes. DeSoto Canyon geologic enigma in that north side is dominated by complex topography associated with downslope movement; south side looks much more “pelagic” in nature—soft sediment cover, morphologically featureless. Effects of physical oceanographic regime on canyon and bathymetry is not well understood.

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