Geologic units in Broome county, New York

Upper Walton Formation (Upper Devonian) at surface, covers 44 % of this area

Shale, sandstone, conglomerate.

Sonyea Group (Upper Devonian) at surface, covers 34 % of this area

In west: Cashaqua and Middlesex Shales. In east: Rye Point Shale; Rock Stream ("Enfield") Siltstone; Pulteney, Sawmill Creek, Johns Creek, and Montour Shales.

Gardeau Formation (Upper Devonian) at surface, covers 12 % of this area

Shale, siltstone; Roricks Glen Shale.

Genesee Group (Upper Devonian) at surface, covers 5 % of this area

West River Shale; Genundewa Limestone; Penn Yan and Geneseo Shales; all except Geneseo replaced eastwardly by Ithaca Formation-shale, siltstone and Sherburne Siltstone.

New Milford Formation (Upper Devonian) at surface, covers 3 % of this area

Sandstone, shale.

Slide Mountain Formation (Upper Devonian) at surface, covers 2 % of this area

Sandstone, shale, conglomerate.

Beers Hill, Dunn Hill, Millport, and Moreland Shales; Grimes Siltstone (Upper Devonian) at surface, covers 0.7 % of this area

Beers Hill, Dunn Hill, Millport, and Moreland Shales; Grimes Siltstone.

Honesdale Formation (Upper Devonian) at surface, covers 0.4 % of this area

Sandstone, shale.

Catskill Formation (Devonian) at surface, covers < 0.1 % of this area

Grayish-red sandstone, siltstone, shale, and mudstone; units of gray sandstone occur in upper part; lithologies in upper part arranged in fining-upward cycles. In the Altoona area, the Catskill Formation is mapped as the Duncannon, Sherman Creek, and Irish Valley Members, which are described under "Central and Eastern Pennsylvania" provinces.

Catskill Formation (Devonian) at surface, covers < 0.1 % of this area

Succession of grayish-red sandstone, siltstone, shale, and mudstone, generally in fining-upward cycles; some gray sandstone and conglomerate.

Lock Haven Formation (Devonian) at surface, covers < 0.1 % of this area

Interbedded olive-gray mudstone, siltstone, sandstone, and thin conglomerate; marine fossils throughout; "Chemung" of earlier workers. Laterally equivalent to Scherr and Foreknobs Formations.