Geologic units in Ulster county, New York

Oneonta Formation (Middle - Upper Devonian) at surface, covers 13 % of this area

Shale, sandstone, conglomerate.

Upper Walton Formation (Upper Devonian) at surface, covers 13 % of this area

Shale, sandstone, conglomerate.

Normanskill Formation (Middle Ordovician) at surface, covers 11 % of this area

Shale, argillite, siltstone.

Austin Glen Formation (Middle Ordovician) at surface, covers 10 % of this area

Graywacke, shale

Lower Walton Formation (Upper Devonian) at surface, covers 10 % of this area

Shale, sandstone, conglomerate.

Plattekill and Ashokan Formations (Middle Devonian) at surface, covers 9 % of this area

Shale, sandstone; Ashokan Formation-shale, sandstone.

Bloomsburg Formation (Upper Silurian) at surface, covers 5 % of this area

Shale, sandstone; Guymard Quartzite; Otisville Shale; Shawangunk Conglomerate-sandstone, conglomerate.

Undifferentiated Lower Hamilton Group (Middle Devonian) at surface, covers 5 % of this area

Panther Mountain, Mount Marion, Stony Hollow, and Union Springs shales and sandstones.

Slide Mountain Formation (Upper Devonian) at surface, covers 4 % of this area

Sandstone, shale, conglomerate.

Onondaga Limestone (Lower to Middle Devonian) at surface, covers 3 % of this area

Seneca, Morehouse (cherty), and Nedrow Limestone Members, Edgecliff cherty Limestone Member, local bioherms, Buttermilk Falls Limestone Member; Schoharie Formation-shale, limestone; Carlisle Center Siltstone; Esopus Shale.

Quassaic Quartzite (Upper Ordovician) at surface, covers 2 % of this area

Quartzite, sandstone, conglomerate.

Moscow Formation (Middle Devonian) at surface, covers 2 % of this area

Shale, sandstone.

Moscow Formation (Middle Devonian) at surface, covers 2 % of this area

In west: Cooperstown and Portland Point shale and sandstone Members; In east: ""Manorkill"" and Portland Point shale and sandstone Members.

Undifferentiated Lower Devonian and Silurian rocks (Lower Devonian - Silurian) at surface, covers 1 % of this area

In northern Ulster County: Port Ewen thru Manlius Limestones; Rondout Dolostone; Binnewater Sandstone; High Falls Shale. In Orange County: Kanhouse Sandstone; Woodbury Creek Formation-shale, sandstone; Esopus Shale; Connelly Conglomerate; Central Valley Sandstone; New Scotland Limestone thru Rondout Dolostone; Decker Limestone; Poxono Island Formation-shale, dolostone; Longwood Shale; Green Pond Conglomerate.

Undifferentiated Hamilton Group (Middle Devonian) at surface, covers 1 % of this area

Shale, siltstone. In eastern Orange County: Skunnemunk Formation-sandstone, conglomerate; Bellvale Formation-shale, sandstone; Cornwall Shale.

Austin Glen Formation (Middle Ordovician) at surface, covers 1 % of this area

Graywacke, shale

Honesdale Formation (Upper Devonian) at surface, covers 1.0 % of this area

Sandstone, shale.

Slide Mountain Formation (Upper Devonian) at surface, covers 0.9 % of this area

Sandstone, shale, conglomerate.

Rondout Formation (Upper Silurian) at surface, covers 0.7 % of this area

Dolostone, limestone; Binnewater Sandstone; High Falls Shale; Warwarsing Limestone; Decker Limestone; Bossardville Limestone; Poxono Island Formation-shale, dolostone.

Onondaga Limestone (Lower to Middle Devonian) at surface, covers 0.7 % of this area

Schoharie Formation-shale, limestone; Carlisle Center Siltstone; Esopus Shale.

Honesdale Formation (Upper Devonian) at surface, covers 0.6 % of this area

Sandstone, shale.

Port Ewen thru Manlius Limestone, Rondout Dolostone, undifferentiated. (Upper Silurian - Lower Devonian) at surface, covers 0.5 % of this area

Port Ewen thru Manlius Limestone, Rondout Dolostone, undifferentiated.

Glenerie Formation (Lower Devonian) at surface, covers 0.5 % of this area

Limestone, chert; Port Jervis Formation (near Port Jervis only)-shale, limestone, chert.

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

Shale, sandstone, conglomerate.

Mount Merino and Indian River Formations (Ordovician) at surface, covers 0.2 % of this area

Shale, slate, cherts.

Helderberg Group (Lower Devonian) at surface, covers 0.1 % of this area

Alsen, Becraft, New Scotland, Kalkberg, Coeymans, and Manlius Limestones.

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

Shale, sandstone, conglomerate.

Plattekill and Ashokan Formations (Middle Devonian) at surface, covers < 0.1 % of this area

Shale, sandstone; Ashokan Formation-shale, sandstone.

Wappinger Group (Cambrian - Lower Ordovician) at surface, covers < 0.1 % of this area

(Including Fishkill limestone and dolostone): Copake Formation ?-limestone, dolostone; Rochdale Formation-limestone, dolostone; Halcyon Lake Dolostone-locally cherty; Briarcliff Dolostone; Pine Plains Formation-dolostone, shale, oolite; Stissing Formation-dolostone, shale.