Continental slope off southwest Florida

Recent surveys of the W. Florida continental slope made by the U. S. Coast and Geodetic Survey show for the first time the detailed topography of the southern part of this area. A marked change in topography at 27 degrees N separates the northern from the southern part of the slope and is related to N-to-S changes from clastic to nonclastic underlying bedrock and from thick to thin or nonexistent overburden of unconsolidated sediments. A drowned barrier spit and lagoon unchanged by subsequent erosion or deposition were revealed at 75-100 fathoms. These features are described and discussed along with numerous long breaks in slope, embayments, and offsets in the steep lower slope, reef patches, domelike structures, and spur-shaped ridges.