Availability of the Colchester coal for mining in northern and western Illinois /

This report is the fourth in a series to assess the availability of coal resources for future mining in Illinois.Includes bibliographical references (p. 17-19).Coal resource classification system. -- Sources of data, limitations and mapping procedures. -- Geology and mining: Colchester coal: floor and roof stratigraphy. -- Coal quality. -- Quadrangle studies.This report is the fourth in a series to assess the availability of coal resources for future mining in Illinois.Mode of access: Internet