Chapultepec Chert is associated with the Chapultepec Member of the Knox Formation occurring as beds, thin layers, or nodules with primary sources occur in the Murphrees Valley of Alabama. In Virginia the Chepultepec Member is associated with the Beekmantown Group and has nodules of white and dark gray to black chert. Exposure occur in southeastern belts in the Valley of Virginia and in the eastern panhandle of West Virginia.