FIGURE 9. Forward seismic model for the proximal- to medial-fan transition channels of the Ross Formation built using GXII seismic modeling software. (A) Outcrop photo of the broad, compensationally stacked channels that dominate the transition from proximal to medial fan setting at Rehy Cliffs (Figure 5). These channels are highly amalgamated in an axial position but become less amalgamated and lower net-to-gross toward the margins. (B) Depth model constructed for this outcrop by applying subsurface rock properties (density and velocity) from deep-water reservoirs in the Gulf of Mexico to the digitized interpretation of this outcrop. The depth model was extended approximately 1 km beyond the outcrop control by continuing the observed patterns of deposition. (C and D) The measured net-to-gross for various points along the model are plotted across the top and can be used to locate seismic models relative to the depth model. Forward seismic models for 30- and 45-Hz peak frequencies are shown. The seismic response for both models is very continuous, but the net-to-gross variations from axis to margin are directly related to the amplitude of the seismic response. This indicates that these distinct lateral changes in sand percentage should be seismically detectable. The individual channels can only be resolved on the higher resolution (45 Hz) seismic model, but there is still substantial interference between the stacked channels (modified from Sullivan et al., 2000b).