A classic Caribbean algal ridge, Holandes Cays, Panama: an algal coated storm deposit

Twenty-seven radiocarbon dates of cores recovered from six drill holes indicate that the relief of the ridge on the seaward edge of the Holandes Cays, San Blas, off the Caribbean coast of Panama, was formed by storm deposits about 2,000 to 2,800 years ago. Although crustose coralline algae are a dominant component of the surface cover on this outer ridge, they played a minor role in the construction of the framework of this bioherm, which therefore cannot be classified as an algal ridge. The framework of the ridge consists dominantly of Agaricia/Millepora rubble that is extensively lithified by micritic submarine Mg-calcite cement. The present-day surface of this area in the Holandes Cays is primarily one of widespread bioerosion with very little indication of substrate accumulation over the past 2,000 years.