a central North American climatic episode dating 7350 to 6540 B.C. This interval marks part of the warming trend between the Late Glacial climatic pattern and the warm dry Altithermal or Atlantic Climatic Episode which was to follow. During this time, the ice sheets retreated and vegetation zones moved towards their modern locations (Wendland l978... of or pertaining to the north, its climate, flora, fauna, environment , resources and peoples; commonly used in reference to the northern forests.