the appalachian basin, during the middle devonian and early mississippian, is characterized by large volumes of deltaic sedimentary rocks that were deposited in the acadian foreland basin as a response to the acadian orogeny. these deposits extend from central new york and pennsylvania westward to ohio, and south along the appalachian mountains through virginia and tennessee to alabama. the acadian delta complex is categorized into two deltas, the catskill delta of middle and upper devonian age, and the price-rockwell (pocono) delta of late devonian and early mississippian age. the acadian delta complex is coupled to the four tectophases of the acadian orogeny, both in terms of provenance and depositional settings. the relief resulting from the orogeny was the fundamental source of the delta sediments.