The Yucatan Peninsula (Figure 67; see Figure 1A and stereo slide pair 5, Appendix D for the regional setting) is a key modern area of carbonate deposition for several reasons.
• The area shows the high degree of variability that can exist along a regional coastline/shelf margin, from a carbonate sand-dominated ramp profile to a rimmed platform margin with fringing or barrier reefs and offshore platforms.
• The northern coastline of the Yucatan Peninsula displays a ramp-type shelf-to-basin profile with a variety of carbonate sand bodies occurring inboard on the ramp along the coastline.
• The areas of Cancun and Cozumel contain superb Holocene and Pleistocene grainstone accumulations that have been thoroughly studied from both depositional and diagenetic aspects.
• Chinchorro Bank, an offshore isolated carbonate platform, shows substantial facies variation between its windward and leeward margins and also illustrates a probable relationship between underlying structure, platform configuration, and depositional patterns in the platform interior.
Most carbonate studies on the Yucatan Peninsula have centered on the Holocene and Pleistocene grainstone-dominated northeastern coastlines in the areas of Cancun and Cozumel (Figure 67). These studies have focused on the depositional and diagenetic characteristics of subtidal, beach, and dune sands. Important results include the analysis of sedimentary structures in both subtidal and eolian deposits; the calibration of the roles played by prevailing northward-flowing currents, storm-generated currents, and antecedent topography in controlling the geometry and structures of the sand bodies; and documentation of the affects of meteoric diagenesis. The modern sediments filling coastal lagoons