the middle devonian to lower mississippian siliciclastic strata, deposited by the catskill delta, includes black shale, gray shale, sandstone, red beds, and minor argillaceous limestone. the strata is deposited in a four-stage pattern that is observed in each tectophase. the formation of the foreland basin through rapid subsidence initiated a transgressive sequences that deposited basinal black shales. after the black shales are deposited, the migration of deformation continues southward, and regression dominates, particularly on the east side of the basin. as collision intensified, subsidence in the foreland basin declined, and sedimentation was replaced by an influx of calcareous silty shales and carbonates. these deposits reflect small transgressive-regressive cycles in a delta-front and delta platform environments. the third stage is represented by regional uplift, which accompanied the collision of an avalon terrane with a promontory, and subsequently, developed a regional disconformity. the fourth and final stage is represented by tectonic quiescence with a widespread carbonate deposition in a slowly transgressing sea.