The southeast Missouri and Illinois-Kentucky districts are two of the most important mineral districts in the country in terms of variety of minerals produced, mineral output, and mineral potential. Both districts lie on faulted structural uplifts within the covered shield area of the Central States. Complex fault lineaments intersect in each district and are major structural controls. Two fault zones, the Ste. Genevieve and Cottage Grove, form connecting links between districts. The iron deposits of southeast Missouri are in rocks of Precambrian age; but the lead, zinc, barite, copper, cobalt, and pyrite deposits of southeast Missouri, and the fluorite, zinc, barite, lead deposits of Illinois-Kentucky, are all in the domed and faulted thin cover of Paleozoic rocks.

A discussion of the mercury, cadmium, germanium, gallium, and strontium content of sphalerite from ore deposits of the Central and Eastern United States.

This compilation of geological and geochemical information on mineral belts in western Sierra County, New Mexico, indicates many new areas favorable for mineral deposit exploration.

Tungsten-rich outcrops may indicate concealed tungsten and beryllium deposits.

The geology, distribution, production, and mining development of deposits of chromite, titaniferous iron ore, rutile, talc, asbestos, magnesite, sodium-rich feldspar, corundum, and serpentine.