At the northeast margin of the Buttle Lake uplift a bed of Pennsylvanian to Permian limestone of the Azure Lake Formation, Buttle Lake Group is folded into a northwesterly plunging syncline. On the east limb the bed outcrops as a band up to 1100 metres wide that extends northeastward from Marble Peak to the west shore of Buttle Lake for 13.3 kilometres. On the west limb the bed forms a narrow, discontinuous band that is extensively faulted.

Overlying basaltic flows of the Upper Triassic Vancouver Group, Karmutsen Formation are preserved along the axis of the syncline. The limestone is underlain by volcanic breccia, tuff and argillite. See H-W (092F 330) for a discussion of the revised nomenclature of Buttle Lake uplift stratigraphy.