A filled shaft at the abandoned Mahoning Coal Company No. 4 slope mine near Coalburg in Hubbard Township, Trumbull County, Ohio. The Mahoning Coal Company No. 4 mine was part of the Sharon (No. 1) coal subsurface mining operation in the Vienna-Coalburg area. The dump had been largely removed, but water seeps and timbers of the shaft along with a large glacial boulder were still visible at the opening to the mine. The area of the mine has shale, siltstone, sandstone, conglomerate, limestone, underclay, coal and flint lithologies. Bedrock is from the Pennsylvanian Geologic Period. The photograph was taken during the summer field work of James Osborn Fuller and Myron T. Sturgeon in July 1941.
