• 59 m of an archaeocyath-Renalcis biohermal facies. These build-ups formed large mound-like structures that measure up to 100 m in lateral extent (an example is transected by the Moro section) and occur for more than 2 km along strike to the north of the section line. Biohermal architecture in the Hideaway Well Member consists of a build-up of closely spaced regular and irregular archaeocyaths bound together by envelopes of encrusting calcimicrobes such as Girvanella, Renalcis and Epiphyton, in addition to irregular archaeocyaths that facilitated sequential biohermal accretion and topographic relief above the surrounding shelf sediments. The flanks of the bioherms are dissected by deep, narrow channels filled with intraclastic carbonate, fragmented shelly debris and micrite that were shed into deeper lagoonal or outer shelf-slope environments. Localised archaeocyath bioherms such as the one transected by the Moro section line are a common feature on the extensive shallow water platform represented by the Wilkawillina Limestone in the Wirrealpa Hinge Zone sensu Gravestock and Cowley (1995).