Henry T. Mullins, 1985. "Modern Deep-Water Carbonates Along the Blake-Bahama Boundary", Deep-Water Carbonates: Buildups, Turbidites, Debris Flows and Chalks—A Core Workshop, Paul D. Crevello, Paul M. Harris
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Piston core and rock dredge samples collected from the modern carbonate slope along the Blake Plateau-Bahama Platform boundary are graphically illustrated in a series of facies maps, core photographs, and thin section as well as SEM photomicrographs. Five facies belts, that parallel the adjacent shelf edge, have been mapped on the basis of their seismic and sedimentary characteristics.
Upper slope facies display a gradual downslope decrease in the degree of submarine cementation from hardgrounds to nodular oozes to unlithified periplatform oozes. The nodular oozes appear to be products of in situ diagenesis during the last glacial maximum and their relative slope position may be valuable for ancient slope reconstructions. Periplatform oozes are heavily bioturbated and massive in appearance, but contain primary vertical variations in diagenetic potential which may explain the well-bedded nature of ancient analogs and possibly provide an interpretation base for paleo-climatic studies.
Lower slope facies are dominantly sediment gravity flow deposits that form a wedge-shaped apron of debris that is distinctly and fundamentally different from the submarine fan model. Coarse grained turbidites and debris flow deposits grade seaward into finer grained basinal facies and bankward into fine-grained upper slope facies which may result in excellent primary stratigraphic traps for hydrocarbons. Rocks recovered from the lower slope are dominantly low-magnesian calcite with only minor primary intergranular porosity but extensive secondary porosity produced by dissolution of aragonitic allochems that may represent promising reservoir facies in the rock record.
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Deep-water carbonates represent on the few frontiers remaining for carbonate exploration and research. The last decade has experienced a rapid evolution in concepts of depositional models and diagenesis which underscores the importance of these deposits as significant reservoirs and source rocks. This workshop displayed cores selected to provide subsurface geologic examples of deepwater carbonates from a variety of depositional settings. Several papers discuss depositional models, platform-to-basin reconstructions, and diagenetic sequences that are important in the development and exploration of Paleozoic carbonate debris flow and turbidite reservoirs of the Palo Duro, Delaware and Midland Basins. Many other examples are included from several different regions.