Cambro-Ordovician of the Illinois Basin


This GeoDigital Information study of the Cambrian and Ordovician sandstones of the Illinois Basin is designed to assist exploration and production geologists in their understanding of factors that control hydrocarbon distribution and production potential in these reservoirs.

Lower Paleozoic rocks in the Illinois Basin occur at depths ranging from 1,000 feet to more than 13,000 feet. Approximately 20 Ordovician oil fields, located mainly near the basin margins, provide evidence that deeper fields may be present in the basin center.

Depositional models have been generated for predicting the regional distribution of the various lithologies, particularly the source and reservoir lithologies, and are integrated to define promising plays and trends for future exploration and development.

The study covers over 50,000 square miles, within which 366 wells were correlated, and represents several man-years of geologic research.

Study Highlights

  • Study Text and Figures
  • 34 Cores Described
  • 366 Study Wells
  • 359 Thinsections Examined
  • 11 Regional and Area Maps
  • 6 Cross Sections
  • 64 Cores Geochemically Analyzed
  • 350 Miles Seismic Lines Examined
  • 9 Key Well Panels

Location Map

Cambro-Ordovician of the Illinois Basin