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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2.6.1 Vinton Geology<br />
Analysis <strong>of</strong> s<strong>eismic</strong> data was <strong>of</strong> the top four seconds so deposition relevant to this study<br />
began on the Vicksburg formation during the Oligocene and continued through the<br />
Miocene. Oligocene stratigraphic units consist <strong>of</strong> the Vicksberg, the Frio, the Hackberry<br />
a subsurface wedge <strong>of</strong> the middle Frio, and the Anahuac formations. Miocene units are<br />
the lower Miocene, middle Miocene, and the upper Miocene (Figure 14). Stratigraphy <strong>of</strong><br />
the Oligocene Frio formation in Calcasieu Parish is complex, due in part to the tectonic<br />
history <strong>of</strong> the lower Frio and the depositional variation in the middle Frio and the<br />
chronostratigraphic equivalent Hackberry. Transgressive and regressive cycles<br />
dominated the Oligocene with a shore zone environment present during the regression<br />
and a marine environment present during the transgression (Figure 15). Oligocene<br />
geology consists <strong>of</strong> eight stages that could have overlapped or occurred at slightly<br />
different times in different places along the upper Gulf <strong>of</strong> Mexico Basin (Paine, 1968).<br />
Miocene deposition shifted to a deltaic environment and back to a broad sandy strand<br />
plain (Galloway et al., 2000).<br />
Sediments deposited in the Oligocene were in marginal marine and shallow marine<br />
environments in the Vinton Dome study area. A complex eight stage depositional history<br />
<strong>of</strong> the Oligocene began with deposition <strong>of</strong> the Vicksberg and lower Frio. Shale<br />
comprising the Vicksberg formation represents a neritic environment. Characterizing<br />
early lower Frio sedimentation is a lowering <strong>of</strong> sea level along the northwest Gulf <strong>of</strong><br />
Mexico Basin resulting in the deposition <strong>of</strong> sand stringers. Following early lower Frio<br />
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