GENERAL PRINCIPLES. 
Ill 
CHART. 
NORTH AMERICAN 
NORTH CAROLINA 
OHIO 
REPRESENTATIVES. 
REPRESENTATIVES. 
REPRESENTATIVES. 
Terrace. Loess. 
Champlain Clays. 
Drift. 
Gravel, Sand and Clay Beds 
of Eastern Counties. 
Terraces, Drift, 
Erie Clay, &c. 
Sumpter Clays. 
Yorktown Marls. 
Claiborne Beds. 
(Wanting.) 
Shell Beds, Marls. 
Limestones. Clays. 
A\ r anting. 
Sandstones. Rotten Lime ■ 
stones. Marls. Lignites. 
(AVanting.) 
Greensand. 
Shell Marls. 
AA'anting. 
Arenaceous Limestones. 
Sandstones, (Rocky Mountains.) 
Wanting. 
Wanting. 
Red Sandstones. Shales. 
Conglomerates. Marls. 
Coal Beds. 
Red Sandstones. 
Coal Measures. 
Conglomerates, Shales. 
AA r anting. 
Dolomites, &c. 
(Missouri, Nebraska.) 
Wanting. 
AVanting. 
Upper Coal Measures. 
Lower Coal Measures. 
Conglomerates. 
Limestones. 
Wanting. 
Coal Measures. 
Conglomerates. 
Limestones. 
Catskill Group. 
Chemung Group. 
Hamilton Shales, &c. 
Corniferous Limestones. 
Oriskany Sandstones. 
AVanting. 
Erie Shales. 
Limestones. 
Sandstones. 
Helderberg Limestones, &e. 
Saliferous Group. 
Niagara and Clinton Limestones. 
Hudson River Shales. 
Trenton Limestones. 
Potsdam Sandstone. 
Wanting ? 
Limestones. 
Shales. 
Conglomerates, Ac. 
Huronian. 
Silicious, Chloritic, 
Clay and Conglomerate Slates. 
No outcrop. 
Laurentian. 
Gneiss, Granite, 
Hornblende Slates, &c. 
No outcrop. 
Igneous. 
Granite, Syenyte, 
Porphyry, &c. 
No outcrop. 
