PRESENT-DAY HALIMEDA CARBONATE SEDIMENTS IN TEMPERATE MEDITERRANEAN EMBAYMENTS - FORNELLS, BALEARIC-ISLANDS

Fornells Bay is an enclosed embayment located in the north of the Balearic Platform in the Western Mediterranean. It displays bioclastic sedimentation with strong terrigenous influences. The plant communities responsible for the carbonate sediment input are the seagrasses Posidonia oceanica and Cymodocea nodosa, and red and green algae, the most important of which is Halimeda tuna. The distribution of the latter is clearly related to bathymetry and it forms the principal bioclastic component (> 40%) in shallow sediments (0-25 m). Red algae are found below 30 m with a characteristic branching coralline algae sea floor. Organic matter in the finest-grained facies attains 6.59%. The bay exhibits a hydrodynamic gradient from low in the interior where there is a terrigenous influence to high in the outer open marine sectors. The presence of Halimeda-rich carbonates and fine-grained terrigenous sediments within Balearic embayments provides an example of Chloralgal facies in a region where Foramol would have been expected. The system described provides new data for the interpretation of fossil temperate-water carbonates.