Leg 76 of the Deep Sea Drilling Project cored 165 m of a 500-m thick Miocene intraclastic chalk formation in the Blake-Bahama Basin. The carbonate material was derived mainly from the Blake Plateau and slopes of Little Bahama Bank with less amounts coming from the shallow platform of Little Bahama Bank. The sediment was transported 150 to 200 mi (240 to 320 km) into the Blake-Bahama Basin via Great Abaco Canyon and Eleuthera Ridge (a Miocene submarine canyon).

Deposition close to the sources was primarily by mass flow or debris flow mechanisms (medium to coarse grains of both shallow- and deeper-water origin float chaotically in a matrix of carbonate mud), whereas turbidite deposition (finely laminated to massive silt and clay-size carbonate) dominates throughout most of the basin. Turbidite sedimentary structures also dominate over debris flow structures in the various facies of this formation.

Upon entering the basin, these chalk turbidites descended below the carbonate compensation depth and eroded and incorporated clasts of partly consolidated siliceous mudstone (the background hemipelagic sedimentation). These clasts of mudstone, as well as clasts of limestone and previously cemented chalk, produce the distinctive appearance so characteristic of this formation.

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