A Deterministic Evaluation of eismic Fidelity using Velocity Modeling ...

surface and a number of small submarine canyons formed for the fifth depositional event.
These events marked the middle Frio Hackberry transgression period (Paine, 1968).
Collapse of the Hackberry (Figure 19) was by subsidence resulting in the retrogradation
of the continental margin (Galloway et al., 2000). Eroded channels filled forming a flat
surface. The sixth major depositional event was deposition of the basal Hackberry on
this flat surface.
The Vinton Dome study area is in the Hackberry embayment that formed during the
middle Frio after a major drop in sea level (Winker, 1982). Characterizing the major
drop in sea level is large-scale syndepositional down-to-the-basin faulting and diapiric
displacement (Galloway, et al., 1982). In the Vinton Dome survey the middle Frio is
absent and has been replaced by the Hackberry (Figures 16 and 17). One of the major
controlling factors of the Hackberry was prominent, positive paleotopographic highs on
the slope and sea floor that had formed from differential loading and sediment ponding
from salt withdrawl, Vinton Dome being one of these highs (LeVie, 1986). A more
prominent structural feature in the Vinton Dome and surrounding areas is the essentially
east-west trend of salt domes with Starks and Vinton Domes on the west and Jennings to
the east (Paine, 1966). Connecting these domes is a large regional fault (Figure 20)
suggesting the preexistence of the salt domes influenced the initiation of the fault and
even controlled its location (Winker, 1982). As sea level increased through deposition of
the Hackberry the Vinton Dome area became a bathyal, continental slope (Figure 21).
Structure mapped in the Hackberry (Figure 22) indicates an extension regime as would be
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