The Late Devonian Catskill Delta is made up of marine and non-marine facies built up on the flank of the tectonic Appalachian Peninsula during assembly of the Old Red (Laurasian) Continent. Much of the continent was under the influence of tropical climates showing a wide range of rainfall. Over the delta, the climate was either tropical wet and dry or desert, due in part, to a rainshadow effect caused by the mountains to the east. Streams showed great variations in discharge and an extended period of drought was an annual event over the region.

Alluvial processes were dominant on land. Braided streams deposited the coarsest sediments on alluvial fans and sinuous, channelized streams deposited sand and mud on the alluvial plains. Interfluves on the alluvial plains were sufficiently long-lived to permit the formation of carbonate soils. Plants were most common near stream courses. Fine sand and mud were carried across the shoreline in distributaries to the floor of the adjacent Catskill Sea. Deltaic processes, wave-related processes, and tides shaped the shore. Wave-related processes and bioturbation modified and reworked the shallow marine sediments while turbidity currents and slow deposition from suspension were most effective over the rest of the basin.