Oakdale-Sil.

Iowa Geological Survey

Located in Johnson County, Iowa, this groundwater monitoring location is associated with a water well in the Silurian-Devonian aquifers.

Well Construction

Depth Description
0.0-164.0 ft 6.0 in diameter steel casing
-2.4-319.0 ft 5.0 in diameter steel casing
310.0-361.5 ft 4.0 in diameter steel casing
Depth Lithology Description
0.0-2.0 ft Quaternary No Color Noted soil or fill
2.0-15.0 ft Quaternary Brown/Yellowish clay
15.0-21.0 ft Quaternary Gray/Yellowish loess
21.0-28.0 ft Quaternary Gray/Bluish clay
28.0-33.0 ft Quaternary Gray/Olive clay
33.0-36.0 ft Quaternary Gray/Yellowish clay
36.0-41.0 ft Quaternary Green/Yellowish till
41.0-46.0 ft Quaternary Brown/Yellowish sand and gravel
46.0-74.0 ft Quaternary Brown/Yellowish till
74.0-80.0 ft Quaternary Gray/Yellowish till
80.0-135.0 ft Quaternary Gray/Bluish till
135.0-137.0 ft Quaternary Gray sand and gravel
137.0-142.0 ft Quaternary Gray/Bluish till
142.0-171.0 ft Quaternary No Color Noted till
171.0-172.0 ft Devonian-Coralville Gray limestone
172.0-188.0 ft Devonian-Coralville/Little Cedar Tan limestone
188.0-228.0 ft Devonian-Little Cedar Gray limestone
228.0-282.0 ft Devonian-Little Cedar/Pinicon Ridge Tan limestone
282.0-298.0 ft Devonian-Pinicon Ridge Brown dolomite
298.0-313.0 ft Devonian-Pinicon Ridge No Color Noted limestone and shale
313.0-327.0 ft Devonian-Otis No Color Noted dolomite and shale
327.0-339.0 ft Devonian-Otis Gray dolomite
339.0-355.0 ft Devonian-Otis;Silurian-Scotch Grove Green shale
355.0-361.5 ft Silurian-Scotch Grove Tan dolomite
361.5-518.0 ft Silurian-Scotch Grove/Hopkinton/Blanding Buff dolomite
518.0-531.5 ft Silurian-Blanding;Ordovician-Maquoketa Green shale

Operated in cooperation with: