Prairie Research Institute

Illinois State Geological Survey

Geological Samples

The Illinois State Geological Survey (ISGS) manages one of the largest collections of geologic samples in the United States. These collections help researchers understand the subsurface geology of Illinois and are used by geologists from the coal and oil and gas industries; quarry operators and mineral prospectors; academic researchers and students; and water, engineering, and consulting companies.

ISGS Collections

For more than 100 years ISGS has collected drilling cuttings in an effort to help its scientists and the public understand the subsurface geology of Illinois. ISGS is the legislatively mandated repository for drill-hole samples in Illinois (State Law 225 ILCS 730/2), including cores drilled for mineral exploration and geologic investigations.

The ISGS collection includes approximately 70,000 sets of well cuttings (rock brought to the surface during drilling) and over 15,000 rock cores (cylindrical rock samples). These collections are valuable records of the approximately 1.5 billion-year-old geologic history of Illinois.

The cuttings come mostly from oil and water wells; the cores come primarily from coal, oil, stratigraphic and mineral tests, engineering studies, and foundation and bridge borings. Most of the core samples on file were condensed from their original form, although in the last 25 years saving continuous core sets has been emphasized. ISGS also houses collections from mines, quarries, outcrops, clay pits, sand and gravel deposits, and Pleistocene glacial deposits.

Access to ISGS geological samples

Scientists, students, and members of the public can view and study samples at the ISGS Geological Samples Library (Natural Resources Studies Annex, 1910 Griffith Dr., Champaign). The library provides a study area equipped with a microscope and ultraviolet light; additional equipment includes two rock-cutting saws and an automated core-slabbing machine. Samples from the ISGS collection are not loaned, but selected sampling of the collection is permitted with prior approval.

Please call 217-333-3567 at least a day ahead of your visit to the library, so ISGS staff can retrieve the requested samples.

No fee is charged for studying samples. If ISGS samples are used for thesis research, students are required to provide a bound copy of their thesis, any thin sections made from the collection, and copies of any slides or photographs made of the samples. Failure to comply may result in the student’s institution losing rights to use the facility.

ISGS Geological Samples Library

Natural Resources Studies Annex
1910 Griffith Drive, Champaign

Open Monday – Friday, 8 a.m. to noon and 1 p.m. to 4:30 p.m. Central. Closed all University of Illinois holidays.

Phone: 217-333-3567
Fax: 217-333-2341
Email:  Jared Thomas