LOWER – MIDDLE FAMENNIAN (UPPER DEVONIAN) MARINE STRATA OF NEW YORK STATE

Famennian strata in New York State represent terrestrial to offshore marine environments that transition through the classic Upper Devonian facies established by stratigraphers in the last century – Catskill – Chemung – Portage – Genesee. Conodonts in more offshore marine strata allow regional and global correlation. The base of the Famennian is within the upper Hanover Shale of the Java Group and the more near shore-equivalent Wiscoy Formation, near the top of a distinct black shale bed – the Upper Kellwasser Horizon equivalent; in the uppermost Wiscoy formation, the extinction of Frasnian brachiopods and the first occurrence of Athyris angelica best approximate the boundary. The Dunkirk Shale at the base of the Canadaway Group, last of the thick Devonian black shales in New York, represents the II E1 flooding of Johnson et al. (1985) in the early Famennian. Higher in the Famennian conodont bearing strata are less common, requiring correlation from strata in Ohio and Kentucky. The II E2 flooding in the Upper crepida Zone likely corresponds to the Corell’s Point Goniatite Bed in the Gowanda Shale of the Canadaway Group. The II E3 flooding in the Lower-Upper marginifera Zone corresponds to the Northeast Shale. The enigmatic plant Protosalvinia, abundant in the Ellicott Shale in western New York, serves as a marker for the Upper trachytera Zone, although the II F flooding may better correspond to the Ellicott Shale, which would make this the Lower to Middle expansa Zone. The Devonian-Carboniferous boundary is recognized by the sequence/event stratigraphy and correlation to conodont-bearing strata in Ohio.