Geologic units in Tompkins county, New York

Genesee Group (Upper Devonian) at surface, covers 47 % 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.

Sonyea Group (Upper Devonian) at surface, covers 30 % 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.

Beers Hill, Dunn Hill, Millport, and Moreland Shales; Grimes Siltstone (Upper Devonian) at surface, covers 21 % of this area

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

Tully Limestone (Middle Devonian) at surface, covers 0.9 % of this area

Tully Limestone

Moscow Formation (Middle Devonian) at surface, covers 0.8 % of this area

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

Gardeau Formation (Upper Devonian) at surface, covers 0.2 % of this area

Shale, siltstone; Roricks Glen Shale.

Ludlowville Formation (Middle Devonian) at surface, covers < 0.1 % 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.

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

Shale, sandstone, conglomerate.