Glacial period and Quaternary glaciations

Sets of phenomena of glaciation that have occurred in large parts of the globe for various periods of geological history that relate to a strong and lasting decrease in temperature.

At certain times in the course of geological time, vast glaciers coated surfaces.

Quaternary glaciation, better known, have been covered in the time of maximum advance, the third part of the surface of the continents. Chronologically, there are four main. These glacial periods have been separated by interglacial periods of warm weather as much or more than today. The great ice sheets have been developed in Quaternary, not so much folded alpine ridges, recent, and in the plains and the foothills of the ancient massifs.

The Great Lakes of North America, the continental ice of South America are some of the results of the last glacial periods.

Definitions
Glaciation: Establishment of the relief resulting from glaciations.
Glacial: a general reduction of temperature in a given region, causing the formation of glaciers.