Geologic units in Lucas county, Ohio

Tymochtee and Greenfield Formations, Undivided (Silurian) at surface, covers 35 % of this area

Dolomite, olive-gray to yellowish- brown, thin to massive bedded, upper two-thirds commonly contains brownish-black to gray shale laminae; locally developed brecciated zones in lower one third.

Salina Group (Silurian) at surface, covers 20 % of this area

Dolomite, gray, yellow-gray to olive-gray, laminated to thin bedded; occasional thin bed and laminae of dark gray shale and anhydrite and/or gypsum; brecciated zones in part.

Antrim Shale (Devonian) at surface, covers 16 % of this area

Shale; dark brown to black; carbonaceous, thinly laminated; 0 to 230 feet thick.

Detroit River Group (Devonian) at surface, covers 12 % of this area

Dolomite; brown to gray; medium to thick bedded; laminated; nodules or interbeds of anhydrite and/or gypsum; basal part becomes sandy dolomite or fine-grained sandstone; as much as 170 feet thick.

Dundee Limestone (Devonian) at surface, covers 7 % of this area

Limestone; olive gray to brown; upper part thin bedded, lower part medium to thick bedded; fossiliferous in upper part becomes cherty dolomite in lower part; as much as 105 feet thick.

Traverse Group (Devonian) at surface, covers 6 % of this area

Dolomite and shale interbedded with limestone; upper part dolomite; gray to light brown; thin to medium bedded; abundant chert; lower part shale interbedded with limestone; olive gray; thin to medium bedded; very fossiliferous; as much as 170 feet thick.

Lockport Dolomite (Silurian) at surface, covers 4 % of this area

Dolomite, shades of white to medium gray, medium to massive bedded, fine to coarse crystalline; fossiliferous; vuggy.

Sunbury and Bedford Formations, Undivided (Devonian and/or Mississippian) at surface, covers 0.2 % of this area

Shale and siltsone; shale, black to brownish-black, carbonaceous in upper one third of interval, gray to bluish-gray, clayey with occasional siltstone lamina and thin beds in lower two-thirds of interval.

Salina Group (Late Silurian) at surface, covers < 0.1 % of this area

Salina Group