Prairie Research Institute

Illinois State Geological Survey


Illinois’ aggregate resources occur in a wide variety of geological settings, from limestone and dolomite bedrock units of differing age to sand-and-gravel deposits formed in diverse river, beach, and glacial settings. The aggregate program:

  • inventories aggregate resources as part of the state’s geological mapping program
  • provides service to Illinois’ aggregate producers and the public using the latest geological research and historical information
  • investigates the feasibility of underground mining and the secondary use of mined-out space
  • maintains a database of existing and abandoned pits and quarries
  • provides mineralogical and geochemical information
  • assists producers in better use of existing resources and locating new sources
  • maintains a repository of data for the characterization of Illinois aggregate resources for present and future exploration
  • compiles information about Illinois mineral production and value and assists industry and the public in estimating reserves and value.

The aggregate program inventories these resources. Construction aggregates have low unit values per ton, but large tonnages of the material are needed for most construction purposes.