Geologic Structure Map of the Northwestern Illinois Zinc-Lad District.
Urbana: Illinois State Geological Survey, 1956. Paperback. Small 4to. Stiff beige wrappers. 7pp. Maps, with large foldout map in rear pocket. Very good. Though internally very good, outer wrappers are age toned, lightly soiled and a bit edgeworn, with "Smallpox Creek Syncline not Prospected" penned large on front wrapper in..... More