Geologic units in Seneca county, New York

Camillus and Syracuse Formations (Upper Silurian) at surface, covers 18 % of this area

Shale, dolostone, gypsum, salt.

Genesee Group (Upper Devonian) at surface, covers 17 % 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.

Ludlowville Formation (Middle Devonian) at surface, covers 13 % of this area

In west: Deep Run Shale, Tichenor Limestone, Wanakah and Ledyard Shales, Centerfield Limestone Members. In east: King Ferry Shale and other members, Stone Mill Sandstone Member.

Skaneateles Formation (Middle Devonian) at surface, covers 11 % of this area

In west: Levanna Shale and Stafford Limestone Members; In east: Butternut, Pompey, and Delphi Station Shale Members, Mottville Sandstone Member.

Onondaga Limestone (Middle Devonian) at surface, covers 10 % of this area

Seneca, Morehouse (cherty), and Nedrow Limestone Members, Edgecliff cherty Limestone Member, local bioherms.

Sonyea Group (Upper Devonian) at surface, covers 10 % 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.

Moscow Formation (Middle Devonian) at surface, covers 7 % of this area

In west: Windom and Kashong Shales, Menteth Limestone Members; In east: Cooperstown Shale Member, Portland Point Limestone Member.

Akron Dolostone (Upper Silurian) at surface, covers 6 % of this area

Bertie Formation - dolostone, shale.

Marcellus Formation (Middle Devonian) at surface, covers 5 % of this area

In west: Oatka Creek Shale Member; In east: Cardiff and Chittenango Shale Members, Cherry Vale Limestone and Union Springs Shale Members.

Tully Limestone (Middle Devonian) at surface, covers 2 % of this area

Tully Limestone

Helderberg Group (Lower Devonian) at surface, covers 1 % of this area

Coeymans and Manlius Limestones; Rondout Dolostone.

Beers Hill, Dunn Hill, Millport, and Moreland Shales; Grimes Siltstone (Upper Devonian) at surface, covers 1 % of this area

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