Geological Survey of Michigan

acid acres alumina amount analysis average barrels basin Black shale Blue clay bog lime bottom brick briquettes burning calcareous calcium carbonate calcium oxide Calorimeter cent channel Chara chemical clay clinker Cloverdale CO₂ coal measures color combustible contains depth feet deep feet thick Fire-clay fixed carbon Geological Survey Grand Ledge gravel Gray shale grinding hard Hardpan heating power inch kiln lake layer limestone located magnesia magnesium carbonate manufacture marl bed marl deposit marsh material Michigan coal miles mill mineral mines mixed moisture muck nearly organic matter peat percentage plant plastic Plate Portland Cement pounds precipitation probably pyrite River rock rotary Saginaw seam salt sample sand Sandrock sandstone sandy Sebewaing shaft shallow shells shore shrinkage silica SiO2 slate soluble soundings springs sulphur temperature tests tion township upper Verne coals vitrification volatile