Mining in the Oraville Quadrangle
The Murphysboro Coal was mined in the Oraville Quadrangle, in small local mines that operated for a short period of time. The seam had a layer of bone coal in the middle of the seam that varied from about 2 inches to over 18 inches thick. This bone coal made for a low-quality product, having a high ash content. The penecontemporaneous Oraville Channel on the east side of T8S-R3W explains the lack of mining adjacent to the eastern channel boundary. Clastic sediments within the Murphysboro Coal body, whether seen in splits, bone coal, or carbonaceous shales, are found in close proximity and are genetically linked to the Oraville Channel (Jacobson 1983).