Strata between the middle Givetian Moscow Formation and the newly recognized Givetian-Frasnian zonal stage boundary, at or near the top of the Lodi Member (Penn Yan Formation of the Genesee Group), include limestone-dominated strata of the Tully Formation and coeval siliciclastic deposits of the Gilboa Formation, overlain by progradational, siliciclastic deposits of the Gen- eseo Formation-Lodi Member succession. The Tully and Gilboa formations, the type expression of the North American provincial Taghanic Stage, correspond to the Polygnathus ansatus–“Ozarkodina” semialternans international conodont zones, and the Global Taghanic Biocrisis interval. The lower, pre-Frasnian part of the Genesee Group, corresponding to the successive hermanni (former hermanni-cristatus Zone), disparilis, and norrisi conodont zones, recorded the onset of a major Acadian tectophase (Tectophase 4; see Ver Straeten, 2023a [Vol. 1, Ch. 1]), timed with coincident deepening of the Devonian foreland basin and major global sea level-rise. The Tully Formation limestone in western and central New York State is an anomalous deposit of dominantly fine grained, medium to dark gray limestone that contrasts greatly with underlying Hamilton Group siliciclastic deposits and overlying pro- gradational siliciclastic facies of the Genesee Group. Tully Formation deposits in western and central New York accumulated on a shallow platform. However, these deposits grade eastward and southward into the equivalent thicker siliciclastic Gilboa Forma- tion, preserved within a structural trough or, possibly, a small-scale orogen-ward migrating basin, in eastern New York and central Pennsylvania that served as a “clastic trap” for siliciclastic sediments which failed to reach the platform. Diachronous basal Geneseo deposits record the westward regional onlap of basinal black mud deposits onto an east-sloping submarine ramp. The Geneseo Formation recorded geologically rapid subsidence and development of a shelf-slope break that imparted a strong control on sedi- mentary magnafacies. The Tully Formation largely displays distinctly clean carbonate deposits in central New York; the Gilboa Formation is herein applied to coeval eastern (shoreward) siliciclastic facies. Post-Gilboa, Geneseo-equivalent onshore divisions, which include the Unadilla Formation, Sherburne Formation, Otego Formation, and Otselic Formation, are, herein, delineated. Most member-scale units of the Tully- and Geneseo-correlative formations, described herein, correspond to divisions based on discontinuity-floored marine sequence and subsequence concepts.