Abundance and distribution of Pb, Zn, Cu and Cd in the Downeys Bluff Limestone, Minerva Mine No. 1, Cave-In-Rock District, Illinois

Includes bibliographical references.Includes illustrations and maps.Trace amounts of Pb, Zn, Cu, and Cd in diamond drill cores from the Downeys Bluff Limestone (one of the host rocks for fluorite-sphalerite ore) in Minerva Mine No. 1, Cave-in-Rock, Illinois, were determined by atomic absorption spectroscopy. An attempt was made to find the abundance and distribution of these elements, and to determine the extent of their dispersion halos (if any) within the host rock. The amounts of Fb, Cu, and Cd present in the non ore-bearing portions of the Downeys Bluff Limestone were below the detection limits of this study and are reported as <1.5 parts per million (ppm), <1.0 ppm, and