Recent dolomitization of quaternary biocalcarenites from fuerteventura (Canary Islands)

Quaternary marine and eolian biocalcarenites in the supratidal breaker and spray zone along the Barlovento coast of the peninsula Jandía, Fuerteventura (Canary Islands) are dolomitized by percolating brines with a high Mg/Ca ratio resulting from evaporation of seawater on the sediment's surface. Only fragments of calcareous algae primarily consisting of high-magnesian calcite are replaced by a cryptocrystalline variety of dolomite. Dolomite also occurs in large euhedral crystals in intraparticle and interparticle pore spaces. In the marine biocalcarenite dolomite has a composition of Ca₅₆Mg₄₄(CO₃)₂. It is well ordered.