Publications

The Great Bahama Bank is a steep sided carbonate platform that can be used as an analogue for the isolated carbonate platform in Southeast Asia. Recently acquired high-resolution multibeam bathymetry and sub-bottom profile data from offshore of Great Bahama Bank allow the assessment of the slope and basin environment. The data cover an area of 6,500 km2 and reveal the variability of the slope morphology and sedimentary processes. These new data will ultimately be able to aid prediction and help develop better reservoir models for carbonate reservoirs in a slope and basin setting. The study area can be divided into four environments: 1) a steep upper slope that is bypassed by basinal sediments, 2) a toe-of-slope with redeposited carbonates that onlaps the bypass slope, 3) a basin floor covered with pelagic sediments, and 4) an elevated seafloor with pockmarks. The uppermost slope is steep and cemented, with declivities ranging from 20° to 70° and averages 40°. The steep slope is onlapped by a sediment wedge that reaches a thickness of 100 m and extends >5 km basinward. Most of the coarse-grained sediment is funneled by closely spaced gullies on the middle slope and deposited as turbidite beds at the toe-of-slope. These turbidite deposits are arranged in lobes and apron system. Margin and slope instability and failure add to the variability of the morphology of the steep slopes. Four areas of platform margin collapse have been identified. Margin collapse features are identified by crooked and convex bankward morphology. The smallest collapse margin scar is 3 km long and the largest scar reaches >20 km long. The 20 km long scar eroded more than 350 m of bank margin and produced a megabreccia bed on the adjacent slope and basin floor. Keywords: multibeam bathymetry, carbonate slope, deep-water, margin collapse.