Frasnian carbonate buildups of southern Belgium: the Arche and Lion members interpreted as atolls

O e facies architecture, sedimentary dynamics and paleogeographic evolution were reconstructed for a number of Frasnian buildups developed on a carbonate platform on the south side of the Dinant Synclinorium (Bel- gium). Bed-by-bed sampling and detailed petrography were complemented by magnetic susceptibility analysis, allowing for high-precision lateral correlation. Six facies were recognised in the buildups, each characterized by a specifi c...