Figure 11. Chirp seismic-reflection profile B–B' with seismic stratigraphic interpretation. See figure 9 for descriptions of stratigraphic units and major unconformities. The red lines indicate reflections that bound seismic stratigraphic units (fig 9). See figures 16 and 18 for profile location. A constant sound velocity of 1,500 meters per second was used to convert two-way travel time to depth, in meters.