The "lost" early ordovician-devonian georgetown carbonate platform of northeastern Australia

Because of approximate equivalence in time, the Crooked Creek Conglomerate, Wairuna Formation (specifically its "Carriers Well" component) and the Perry Creek Formation (of the Broken River and Camel Creek regions) are interpreted as segments of the same former sedimentary wedge, deepening to the E/NE, its development being a reflection of Ordovician- Silurian events on the adjacent Georgetown Block - and specifically existence and persistence of a substantial carbonate platform (the Georgetown Carbonate Platform) from late Early Ordovician to early Wenlock over part of the Block. Carbonate sedimentation continued (perhaps intermittently, or with expansion and contraction of the carbonate platform) from later Wenlock through to about the Givetian-Frasnian boundary; this is clearly expressed in the autochthonous and associated allochthonous sequences in the Broken River area sensu stricto and by less chronologically constrained limestone olistoliths in the Kangaroo Hills Formation of the Camel Creek region. Remains of the former carbonate platform on the Georgetown Block are limited to two Devonian clastic-carbonate sequences preserved as tectonic slivers.