Seismic Stratigraphy of Lower Cretaceous Carbonate Platforms and Margins, Eastern Gulf of Mexico: ABSTRACT

The Role of Fluid Seepage in the Erosion of Mesozoic Carbonate Escarpments

“…The occurrence of patches of talus composed of rectangular blocks on the canyon floors, indicative of periodic collapse, are more common at the base of the canyon heads (Paull, Twichell, et al, 1991). The growth rate of the box canyon in our main scenario is estimated at 10 km per 100 Ma, which compares well with the escarpment retreat of 8 km in the last 100 Ma inferred from geophysical data (Corso & Buffler, 1985;Freeman-Lynde, 1983;Paull, Freeman-Lynde, et al, 1990).…”

“…Examples of lines of evidence include: (a) the strata exposed across carbonate escarpments are platform interior deposits (predominantly mudstones and wackestones) rather than high energy facies typical of modern platform edges (e.g., grainstone, boundstone or bafflestone), (b) the freshness and abraded texture of rocks exposed across the escarpment, (c) the low thickness of sediment cover and lack of Fe-Mn coatings on the escarpment face, (d) the abrupt termination of seismic reflections at escarpments, and (e) the occurrence of buried benches at the base of some escarpments, which have been interpreted as evidence of retreat by erosional undercutting (Dillon et al, 1987;Freeman-Lynde, 1983;Freeman-Lynde & Ryan, 1985;Kohl, 1985;Land et al, 1999;Paull & Dillon, 1980;Paull, Freeman-Lynde, et al, 1990;Schlager et al, 1984). The Blake Escarpment in the vicinity of the Blake Spur, for example, is thought to have retreated by up to 15 km since the Oligocene (Dillon et al, 1987;Paull & Dillon, 1980), whereas the southern Florida Escarpment may have retreated by up to 8 km in the last 100 Ma (Corso & Buffler, 1985;Freeman-Lynde, 1983;Paull, Freeman-Lynde, et al, 1990).…”