USGS Home
Contact USGS
Search USGS

Systematic Mapping of Bedrock and Habitats along the Florida Reef Tract—Central Key Largo to Halfmoon Shoal (Gulf of Mexico)

USGS Professional Paper 1751

by Barbara H. Lidz, Christopher D. Reich, and Eugene A. Shinn

Introduction: Table of Contents Project Overview Project Objective Geologic Setting Primary Datasets Primary Products - Overview Maps & Evolution Overview: Introduction Depth to Pleistocene Bedrock Surface Reef & Sediment Thickness Benthic Ecosystems & Environments Sedimentary Grains in 1989 Summary Illustration Index Map Evolution Overview Tile-by-Tile Analysis Organization of Report Tiles: 1, 2, 3, 4, 5, 6, 7/8, 9/10, 11 Summary Acknowledg- ments References Disclaimer Related Publications

Tile 7/8 Geography Sector-Specific Studies Geologic Highlights Margin Evolution Flooding the Florida Shelf Addendum Ephemeral Islands and Lighthouses Tile 7 coordinates: 24°32'45.48" N. 81°57'30.42" W. 24°36'02.98" N. 81°41'31.68" W. 24°28'47.74" N. 81°39'40.82" W. 24°25'23.88" N. 81°55'44.04" W. Tile 8 coordinates: 24°40'06.44" N. 81°59'21.08" W. 24°43'24.96" N. 81°43'17.04" W. 24°36'02.98" N. 81°41'31.68" W. 24°32'45.48" N. 81°57'30.42" W. Major Geographic Sites: Tile 7/8 (lower Keys) includes Boca Chica Key, Key West, and Fleming Key, the westernmost islands in the chain of Florida Keys (Fig. 97A, 97C; 97B shows the middle and upper Keys). Offshore reefs include Middle Sambo, Western Sambo, Eastern Dry Rocks, Rock Key Reef, and Sand Key Reef. Reefs at Eastern Sambo are a Research Only Area (see Marine Sanctuaries). Those at Western Sambo lie along the south boundary of the Western Sambo Ecological Reserve, a fully protected area that extends north-northeast to the shoreline of Boca Chica Key. Reefs at Eastern Dry Rocks, Rock Key, and Sand Key are Sanctuary Preservation Areas and lie just within the southeast corner of the Key West National Wildlife Refuge. The Refuge extends north and west from the west end of Key West to include the Marquesas Keys (Fig. 97C). Figure 97. (A) Landsat satellite image of south Florida shows individual tile boundaries (blue rectangles) of this regional study in the Florida Keys National Marine Sanctuary. Tile 7/8 is highlighted. (B) Index map shows locations of named reefs and shoals in the upper Keys and northeastern middle Keys, delineated by dashed lines. Most named reefs and shoals were once historic islands. Red rectangles show geographic boundaries of Tiles 1, 2, 3, and 4. (C) Contiguous part of index map shows westernmost part of middle Keys and the lower Keys (dashed lines). Red rectangles show geographic boundaries of Tiles 5, 6, 7, and 8, with Tile 7/8 (here considered a single tile) and its geographic sites highlighted. Black-dot rectangle shows area of Key West National Wildlife Refuge. Sanctuary boundary is in red; shelf-margin contour is in blue. Contours are in meters. [larger version] continue to: Sector-Specific Studies

Coastal & Marine Geology Program > Center for Coastal & Watershed Studies > Professional Paper 1751