Onset, growth, decline and decease of the Frasnian reefs and carbonate platform in the Frasnian of Belgium (original) (raw)

The Belgian Frasnian was investigated for a long time and displays well dated and correlatable sections. They allow to document the evolution of the carbonate platform and buildups, and their decease relating to the Frasnian crises. The sequence stratigraphy of the Middle and Upper Frasnian was revised here and has allowed to establish that the development of the buildups was well correlated with the third-order sequences. During the Middle Frasian, the onset and vertical growth of the three levels of reefs (" Arche " , " Boverie " and " Lion ") correspond to the transgressive system tract (TST) of the sequences. During the high-stand (HST) and the falling-stage system tracts (FSST), their vertical growth decreased, and they evolved to progradant carbonate platforms, 1 – 3 km wide and un to140 m high (including the biohermal core), in which bounstone are replaced by packstone – grainstone, then by shallow-water and intertidal mudstone (FSST). There is n...