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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<strong>of</strong> the upper Frio. Overlying the lower portion <strong>of</strong> the upper Frio are two thick sand beds<br />
separated by a shale bed (Tabbi-Anneni, 1975).<br />
At the upper Oligocene series, the Anahuac Formation overlies the Frio Formation and<br />
underlies the lower Miocene. Deposition <strong>of</strong> the 1400 feet thick Anahuac occurred in an<br />
outer neritic environment. Sediments are composed <strong>of</strong> calcareous shales with sporadic<br />
alternating sand (Tabbi-Anneni, 1975). There are three biostratigraphic units in the<br />
Anahuac. In ascending order, these include the Marginulina, the Heterostegina, and the<br />
Discorbis zones (Tabbi-Anneni, 1975).<br />
Overlying the Anahuac formation is the Miocene Series. Deltaic and continental<br />
environments typify this 7000 - 7500 feet thick interval. Sediments are composed mainly<br />
<strong>of</strong> massive sands with periodic shale breaks. Common micr<strong>of</strong>ossils found in the Miocene<br />
are Operculinoides sp. and Amphistegina sp. (Tabbi-Anneni, 1975).<br />
2.4 Salt Tectonics<br />
Understanding mechanisms for salt emplacement and movement are important to<br />
understanding the formation and dynamics <strong>of</strong> individual salt bodies such as Vinton<br />
Dome. Developing a comprehensive model requires accurate evaluation <strong>of</strong> events that<br />
led to the current salt geometry. Another important aspect <strong>of</strong> model development is<br />
proper identification <strong>of</strong> key stress, loading, tectonic mechanisms, and ways to distinguish<br />
which mechanisms were factors at what times. Geologic processes such as depositional<br />
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