The recognizable facie of the member in excavated or eroded exposures is two thin limestone beds separated a bed of shale and adjacent shales above and below having a particular gray or bluish color darker than higher limestones.

A third, lower, highly variable algal limestone is often present and included as the base of the member.

The addition of the lower algal limestone as a base for the unit increases the thickness to over 18 feet (5.5 meters).

The stromatolite base of this limestone can overlie orange lime-sand mudstone to grainstone recording the advancement a shoreline through the area creating the open shallow sea environment where the upper limestones would form.

[4][5][7] As much of the Americus environment was shallow seawater with tidal currents, the formation is known for abundant, fragmented, and sorted remains of fusilinids, crinoids, brachiopods, and stromatolites.