Geologic units in Niagara county, New York

Queenston Shale (Upper Ordovician) at surface, covers 52 % of this area

Queenston Shale

Lockport Group (Upper Silurian) at surface, covers 26 % of this area

Consists of: Guelph, Oak Orchard, Eramosa, and Goat Island Dolostones; Gasport Limestone-local bioherms.

Camillus, Syracuse, and Vernon Formations (Upper Silurian) at surface, covers 16 % of this area

Shale, dolostone, salt, and gypsum.

Medina Group (Lower Silurian) at surface, covers 3 % of this area

Consists of: Thorold Sandstone; Grimsby Formation-sandstone, shale; Power Glen and Cabot Head Shales; Whirlpool Sandstone.

Irondequoit Limestone thru Kodak Sandstone (Lower Silurian) at surface, covers 2 % of this area

Includes: Irondequoit Limestone, Rockway Dolostone, Hickory Corners Limestone, Neahga Shale, and Kodak Sandstone.

Decew Dolostone and Rochester Shale (Lower Silurian) at surface, covers 1 % of this area

Decew Dolostone and Rochester Shale