The Silurian Upper Burgsvik and Lower Hamra-Sundre Beds, Gotland

Five facies are recognized in the Upper Burgsvik and Lower Hamra-Sundre Beds on account of a lithological and paleobiological analysis: I) siliciclastic, II) bioclastic, III) oolitic/pisolitic, IV) oncolitic/biostromal, and V) crinoidal facies. The facies represent five depositional environments: a beach, a fore-shore, a surf, a shallow marine current, and an off-shore environment. The diversity and colony shape of tabulates in facies IV is related to discrete physical and biological factors. The succession of facies reflects a transgressive sequence. Land was situated in the north-west.