Published:January 01, 1994
In the previous sections, a series of tectonic and oppositional models for the geologic evolution of the Louisiana offshore have been presented. These models appear to be applicable certainly to the Upper cenozoic, Miocene to present, and quite possibly back to initiation of continental margin deposition in the South Louisiana Basin. The models have depicted lateral Louann Salt migration, suggested possible rates of migration for the several different features, predicted lateral tears in the advancing salt, indicated potential impact of salt ridges onto evolution of shelf-break growth-faults, and computer modeling of fracturing about the various types of migrating salt features, each with their own genetics.
Depositional stratigraphy is mixed with the tectonics as the two processes are synergistic. Incoming sediments provide the lithostatic pressures, pushed by omnipresent gravity. The underlying semi-plastic salt and shale masses are pushed into their present configurations by the changing lithostatic and hydrostatic pressures. Lithostatic pressures, resulting from sedimentation, vary with increased deposition and erosion. Hydrostatic pressures vary through geologic time as the potential sediment accommodation volume varies with time, regional subsidence, and sealevel oscillation.
It is clearly understood that within the sedimentary record of the Louisiana offshore there are recognizable cycles, from 1st order through at least 4th order, see “Stratigraphic Units” section, and possibly even 5th order sequences. As these global processes are occurring with their own intertwining synergistic effects, they are also impacting, at different frequencies, the semi-plastic salt and shale sheath underlying the encroaching and agrading sediments. Thus, sedimentation shows up to
Figures & Tables
Seismic Stratigraphy and Hydrocarbon Traps: Louisiana Onshore and Offshore
“Synergisms among tectonics, sedimentation, and climate/sealevel oscillations provide hydrocarbon source, reservoirs, and traps. This book from the SEG Course Notes series examines these traits, as they exist in the on- and offshore region of Louisiana.”