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Niagaran Series

Gower Dolomite- LeClaire (reef phase) tough, greenish-blue dolomite; Anamosa (inner-reef) soft, yellowish-brown, thin-bedded dolomite. Hopkinton Dolomite- light colored dolomite with nodular chert.
State Iowa
Name Niagaran Series
Geologic age Phanerozoic | Paleozoic | Silurian
Comments Approx total thickness 300 ft
Primary rock type dolostone (dolomite)
Secondary rock type chert
Other rock types
Lithologic constituents
Major
Sedimentary > Carbonate > Dolostone (Bed)
Incidental
Sedimentary > Chemical > Chert (Bed)
Map references
Hershey H. G. 1969, Geologic Map of Iowa: Iowa Geological Survey, scale 1:500K
Unit references
Hershey H. G. 1969, Geologic Map of Iowa: Iowa Geological Survey, scale 1:500K
Counties Black Hawk - Bremer - Cedar - Clayton - Delaware - Fayette - Linn - Scott - Winneshiek