Mount Olive Quadrangle

The mines in the Gillespie South Quadrangle operated for long periods, with only two of the ten operating for less than 20 years. The longest-running mine was the Staunton No. 7 Mine (mine index 189), which operated for over 70 years. The four Superior Coal Company mines operated between 36 and 48 years each, and were among the most productive mines in the state during World War I. Employment at these mines was fairly stable during the Great Depression in spite of frequent idling of the mines, the result of an agreement between the Superior Coal Company and the unions to share out the work among the men instead of layoffs.

The coal thickness in the Mount Olive Quadrangle ranged from below 5 feet thick to over 9 feet thick. Depths ranged from 290 to about 350 feet.

The roof conditions described in several mines were similar. Below the persistent, competent limestone was a crumbly gray shale, then a green and brown shale. Below that was a lenticular limestone that ranged from 0 to 12 inches thick, with a light gray shale (usually referred to as “clod”) and below that a massive black shale. The clod and dark gray shale did not hold very well. Some mines left 14 to 22 inches of top coal to help keep the roof up, but some roof falls went to the upper limestone. Leaving the top coal protected the shale from the changes in humidity and other effects of weathering, and slowed the deterioration. Most of these mines operated prior to roof bolting (the earliest roof bolting was in this area in 1947, in Staunton No. 7 Mine, mine index 189), and timbering was used to keep the roof up. In another area, limestone protrusions (sometimes referred to as bosses) extended down into the coal seam. They were inferred to be derived by pressure, as the black shale and coal below was usually shattered with pinwheel slips around the protrusions.

Coal Mines In Illinois Mount Olive Quadrangle