Pinnacle reef complex.
ensensis to varcus Zone
650 m wide - 125 m thick.
Colonial corals (rugose and tabulate) and massive and tubular stromatoporoids surrounded by sand gravel sized crinoid coral sediment. Much of the reef is composed of fragmented reef-derived debris
Several algae and some microbes. Rare bryozoans.
Not more than 10 % micrite in reef core.
15 species or rugose corals in framework indicated by ref. 1600. Rugosa as primary frame builders.

Abstract of ref. 1603:
Agastophyllum eximium gen. et sp. nov., a massive digonphyllid coral, is described from the reef flat and organic reef macrofacies of Vopni and Lerbekmo (1972). Dialeptophyllum vopnii gen. et sp. nov., a solitary kyphophyllid coral, is described from the reef flank macrofacies. Thryptophyllum undafundus gen. et sp. nov. is described from the reef flat and reef flank macrofacies, and is referred to a new subfamily of the named Thrptophyllinae. Agastophyllum eximium and Thryptophyllum undafundus are Giventian, Middle varcus zone age; Dialeptophyllum vopnii is presumed to belong to the same zone, and is certainly Givetian. Four undescribed species of Agastophyllum are reported from late Eifelian strata of Western Canada. Dialeptophyllum vopnii and an unnamed Emsian species from the Nelichen Formation of the Indigirka River drainage area of the northeastern Soviet Union are the only known species of Dialeptophyllum. An early Givetian species from the Rockport Quarry Limestone of Michigan, originally described by Ehlers and Stumm (1949), under the name Spongophyllum romingeri, is transferred to the new genus Thryptophyllum. 