Mining in the Depue Quadrangle
In the northwestern portion of the Depue Quadrangle, the Herrin Coal was mined with the room-and-pillar method. Clay slips were common in this seam, and the blue band was 3 inches thick in the Coal Hollow Mine (mine index 244). The earliest mining in this area took place in the Herrin Coal, along East Bureau Creek near Coal Hollow. The extent of mining is not known, but 7 mines were shown on the 1876 Atlas of Illinois.
In the eastern half of the quadrangle, longwall mining took place in the Colchester Coal. The roof was poor in the Marquette Mine (mine index 8), so that the weight of the roof compressed the gob stacked behind the active face, and subsidence breaks to the surface were noted. Pyrite was present in a clay parting and as nodules and lenses. The Spring Valley No. 4 Mine (mine index 241) had a thick underclay floor that was more than 14 feet thick.