Lake County | Quaternary | Maquoketa Formation | Silurian | Galena-Platteville Interval | Ancell Formation
Ironton-Galesville | Eau Claire Formation | Mt. Simon Sandstone | Cross Sections


Bedrock Topography, Thickness Maps and a Three-dimensional Model of Silurian Rocks in Lake County, Illinois

        Bedrock topography of Lake County, Illinois.         Image of a map showing the thickness of the Silurian rocks in Lake County, Illinois.
Three-dimensional representation of the thickness of the Silurian age strata

Silurian

Silurian rocks, consisting mainly of pure to silty dolomite, form the most important bedrock aquifer supplying residences in Lake County. Local porosity and permeability are mainly the result of fractures and dissolution cavities in the dolomite. There is little to no matrix porosity; therefore the dolomite does not have adequate capacity for municipal water wells. The water is recharged locally from precipitation and is susceptible to groundwater contamination.

Left is a three-dimensional representation of the thickness of the Silurian age strata.



Updated 10/27/2009 SLD

ILLINOIS STATE GEOLOGICAL SURVEY
615 E. Peabody
Champaign, IL 61820
217-333-4747
info@isgs.illinois.edu

Terms of use         Privacy Statement

© 2012 University of Illinois Board of Trustees. All rights reserved.
For permissions information, contact the Illinois State Geological Survey.