The Lisburne Group is a thick sequence of Carboniferous carbonate rocks in northern Alaska. It was deposited on a passive continental margin as a laterally extensive, south-ward dipping carbonate ramp that thickens to the south and depositionally onlaps older rocks to the north. In autochthonous and parautochthonous areas (northernmost Brooks Range and North Slope subsurface) the Lisburne is subdivided into the Alapah and Wahoo Limestones. In allochthons to the south these units are underlain by the older Wachsmuth Limestone. The Wahoo is a producing reservoir rock at Prudhoe Bay and its stratigraphy has been documented in some detail. The Wachsmuth and Alapah have received much less attention and their stratigraphy is poorly understood.

During summer 2000 six partial Lisburne Group stratigraphic sections were described in the Philip Smith Mountains to document the stratigraphic architecture in this relatively unstudied area. Here the lower Lisburne is approximately 700 meters thick and is overlain by a thin veneer of Wahoo. The lower Lisburne can be subdivided into three informal units based on their weathering profile.

The lowermost 350 meters overlies the Kayak Shale, is relatively resistant, and displays dark (cherty limestone) and light banding (limestone) similar to that described in the Wachsmuth Limestone. The unit consists of several thick packages of nodular or bedded chert and crinoid-bryozoan wackestone with large subhorizontal, silicified burrows. These facies are overlain by meter-thick crinoid rudstones with reworked coral fragments. The cherty wackestones are interpreted to have been deposited below fairweather wave base in a deep ramp environment. Crinoid rudstones are interpreted as shoals. Conodonts recovered near the top of the interval indicate a Meramecian age.

The middle interval is 200 meters thick, cyclic, has a recessive weathering profile, and is darker colored than the lower unit. Cycles begin with greenish, calcareous shale that coarsens upward to crinoid-bryozoan-coral grainstone to rudstone and coral framestone. Basal shales drape over coral heads that form the top of subjacent cycles. Progressively coarsening upward cycles indicate a progradational facies stacking pattern. Calcite replaced evaporites observed at the Middle-Upper Alapah contact and the cycle stacking pattern a are interpreted to indicate shallowing upward from deep ramp to shallow subtidal environments.

The upper 150 m thick package is relatively resistant, light in color, cyclic, and grainer than the middle interval. Cycles are a few meters to tens of meters thick. They coarsen upward from crinoid-bryozoan wackestone to crinoid-bryozoan packstone to grainstone. The cycles become muddier and bryozoan and chert abundance increases upward. The stratal stacking pattern and fauna indicate a change from open to restricted lagoonal environments on a shallow ramp and conodonts indicate a Chesterian age.

The Lisburne Group in the Philip Smith Mountains records initiation of deep-water carbonate ramp sedimentation atop the underlying Kayak Shale. Two major episodes of transgression and shallowing upward indicate significant relative changes in sea-level. Meramecian conodonts and lithofacies similar to the Wachsmuth Limestone in the lower interval imply that these rocks are allochthonous and are most likely part of the Endicott Mountains allochthon. The upper two intervals appear to correlate with the Alapah Limestone to the north.