The outcrop on the left(Stop 4a HAZ Geotour 2020), at the top of the stairway, is mainly well-bedded chert that is tightly folded and cut by post kinematic feldspar porphyry dikes. Pyrite mineralization is associated with these dikes. Fabrice Cordey has identified Middle Triassic radiolaria in a sample of chert collected from this site. The cherts apparently unconformably overlie Late Carboniferous to Early Permian limestone of the Asitka Group.
To the east the chert is overlain by and in part structurally imbricated with chlorite and sericite schist of probable Late Triassic age (Takla protolith?).
From the first platform on the stairway going down to river level we get a good view of the north wall(Stop 4b HAZ Geotour2020) of the canyon below the Fulton River dam. If the light is appropriate one can discern contorted, near vertical beds of limestone, chert and metasediments cut by dikes. This exposure shows how deformed the Asitka and Takla rocks are at this locality. The age of this deformation is believed to be Middle Jurassic.