Labels:dialog box | window OCR: Legend for Coal Maps Igneous and Metamorphic Rock not underlain bv any coal- -bearing rocks Cretaceous Rock Contains bituminous and subbituminous coal beds around margins of coal field well as at depths in the center of the field Non-bearing rocks at surface underlain bv coal bearing rocks at the subsurface Rocks Contains abundant thick laterally continuous beds of subbituminou coal Sedementary rocks not underlain bv coal bearing fields continuou