Figure 69. Index map shows USGS seismic tracklines (red) in upper and middle Florida Keys and those portions of profile data selected (bold black) from the Tile 1, 2, and 4 sectors for illustration with their figure numbers (modified from Lidz et al., 2003). Note that profiles illustrated in Tiles 2 (Fig. 49B) and 4 (Figs. 70, 72, 73, 74B) were acquired in 1997 and constitute part of the 'new' high-resolution seismic data used to develop the updated Bedrock Surface and Sediment Thickness maps. Shelf-margin contour (blue) is in meters.