A Deterministic Evaluation of eismic Fidelity using Velocity Modeling ...
A Deterministic Evaluation of eismic Fidelity using Velocity Modeling ...
A Deterministic Evaluation of eismic Fidelity using Velocity Modeling ...
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loading and faulting are the major processes that typically affect the evolution <strong>of</strong> salt<br />
bodies. Shown in Figure 5 (see below) are types <strong>of</strong> salt features recognized in the Upper<br />
Continental Margin <strong>of</strong> the Gulf Coast Basin.<br />
Salt body formation is generally in restricted basins and deposited as sub-horizontal beds.<br />
Salt has a low density and yield strength, and will flow in the solid state by gravity alone.<br />
Factors influencing flow are temperature, pressure, and the presence <strong>of</strong> impurities. Water<br />
will increase diffusive flow and non-evaporite minerals will reduce plasticity. Salt flow<br />
will result in the transformation <strong>of</strong> a tabular body into a variety <strong>of</strong> geometric structures.<br />
Salt beds generally deform into concordant low-amplitude structures such as salt<br />
anticlines, rollers and pillows that may evolve into discordant high-amplitude diapiric<br />
structures such as salt walls, stocks, nappes, and detached teardrop units, and may<br />
eventually form into extrusions (Figure 5) (Jackson and Talbot, 1986). Deformation can<br />
stop at any time and reactivate at a later period. A diapiric structure is the reference to a<br />
salt body that either pierces or appears to have pierced the overburden. A salt dome is the<br />
term applied to diapirs such as salt pillows or stocks and their surrounding arched strata<br />
(Jackson and Talbot, 1986).<br />
Based on experimental modeling, one classification system <strong>of</strong> diapers is in three stages.<br />
Reactive diapirs that initiate and grow under grabens formed by extension <strong>of</strong> the<br />
overburden, active diapirs that rise by pushing aside thinned overburden, and passive<br />
diapirs that grow by downbuilding (Vendeville and Jackson, 1992). Downbuilding<br />
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