GEOLOGIC FRAMEWORK AND RECENT GEOLOGIC HISTORY OF THE WEST-CENTRAL FLORIDA INNER CONTINENTAL SHELF AND BARRIER ISLAND SYSTEM: SUMMARY OF FINDINGS

This paper presents the summary of 5 years of research funded by the USGS Center for Coastal Geology and Regional Marine Studies (St. Petersburg, FL) of the northern portion of west-central Florida barrier island coast and its adjacent inner continental shelf. The work effort focused on the geologic framework, but inner shelf and coastal physical processes were included as well. The results are presented in a suite of 20 USGS Open-File Reports, which are being produced in CD-ROM format and are appearing on the USGS web site (http://coastal.er.usgs.gov/wfla/).

This coast is one of the most morphologically complex barrier island systems in the world as it presents elements of wave and tide-dominated coastal systems that are immediately juxtaposed. In addition, this coast offers contradictions in that it is known as a low energy sediment starved system, yet is dominated by overwash, and features the largest ebb-tidal delta within the Gulf of Mexico. It is also dominated by siliciclastic sediments, yet headlands, embayments, and regional barrier-island trends are controlled by underlying antecedent topography superimposed on limestone basement.

The geologic framework approach generated: (1) models of coastal and shelf evolution during the past 8,000 years, (2) stratigraphic links between the barrier islands to the adjacent inner shelf, (3) the recognition of distinct shelf provinces tied to sediment type, the distribution of linear sand ridges, bedforms, and ebb-tidal deltas, and (4) the distribution of exposed limestone outcrops and live hardbottoms.

These USGS Open-File Reports, including a summary of findings, will assist members of the public, coastal managers, engineers, and government leaders to utilize coastal resources, both living and nonliving, more effectively along this heavily-populated portion of the US coastline.