Pinnacle reefs seaward of Presqu'ile Barrier.
Varaibly dolomitized.
Dominated by bulbous and tabular stromatoporoids.
Rugose corals represent by small branching forms (particaularly Dendrostella trigemme) enlosed in stromatop.

Abstract of ref. 1600:
Rugose corals of mid-late Eifelian age are diverse and relatively abundant in widespread open shelf carbonates of Northeastern British Columbia (lower Keg River and Dunedin formations) and District of Mackenzie (Lonely Bay, Nahanni, Headless and Hume formations). The overlying Givetian carbonate complex of northeastern British Columbia and southern District of Mackenzie (Presqu'ile Barrier) has only sparsely developed rugosans, but beds flanking the barrier (upper Dunedin, Pine Point, Sulphur Point formations) locally develop more diverse faunas of early-mid Givetian age. Downslope from the barrier complex, numerous early-mid Givetian pinnacle reefs (upper Keg River, Hom Plateau formations) bear particularly diverse and abundant rugose coral assemblages. In the lower Mackenzie River valley of northern District of Mackenzie a series of reefal complexes of mid-late Givetian age (Ramparts Formation) carries significant rugosan faunas, especially in platform and flanking beds.