Age, facies, and geometry of the Sandbian/Katian (Upper Ordovician) pelmatozoan-bryozoan-receptaculitid reefs of the Vasalemma Formation, northern Estonia
The Vasalemma Formation (early Katian, Late Ordovician) of northern Estonia consists of a succession of biodetrital grainstones up to 15 m thick with numerous intercalated reef bodies, which reach diameters of more than 50 m. Four dominant facies types are distinguished within the reef core limestones: (1) a bryozoan framestone-bindstone, (2) an echinoderm bindstone, (3) a receptaculitid-bryozoan-