Annual Report for ... with Accompanying Papers, Band 2

argillaceous basin bituminous shale bluffs calcareous clay seams Clay shale coal bearing coal beds coal field Coal Measures coal seams coal vein Coalport compact considerable county line creek Cretaceous dark deposits Devonian district drift entire exposures extensive farther feet deep feet in depth feet in thickness Figure Fire clay Fire clay exposed fissile formation Fort Dodge four feet geological gray half a mile impure inches in thickness Iowa Iowa coal Kaskaskia Keokuk Kinderhook known layers light colored lithological Louis limestone Lower Carboniferous Lower Coal Measures Mahaska county Marion county mines Mississippi Missouri Moines river number of places opened operated outcrops Paleozoic portion present Raccoon river railroad Redrock region rocks roof Saint Louis limestone sandstone sandy seams of coal sediments shaft shaly short distance slope southwestern strata stratigraphical stream surface tion unconformably valley vein of coal vicinity water level ΙΟ