Uranium has been sought in Illinois by many people in recent years. The
Geological Survey also carried out a wide search for uranium and
particular attention was paid to certain clays and other rocks in Hardin
County and certain black shales in other parts of the state.
About 200 samples from Hardin County and 175 samples of the shales were
tested by the Survey. No deposits were found that are known to be of the
required richness and quantity.