The two main structural features in the Atlantic Region are the Appalachian Mountains and the Canadian Shield. Appalachians are made up of: sedimentary rock- layers of rock particles and sand that have been under pressure and form rock metamorphic rock- formed from sedimentary rocks which change due to heat and pressure.

Canadian Shield is made up of: Igneous Rock  formed after volcanic activity brings molten magma to the surface. The magma cools to form igneous rock. There is also Metamorphic Rock. The Canadian Shield has been exposed in many places because of the intense pressure and scraping action of the glaciers during the last ice age. Much of the Shield is therefore fairly flat and many small lakes and ponds fill in any depressions.

The Canadian Shield As you can see the Canadian Shield is fairly flat, and there are many small ponds and lakes. This picture was taken in Northern Quebec.

How are Mountains Formed? One way is when tectonic plates are diverging or moving apart. Magma comes to the surface and can form volcanoes A second way is when plates converge or move together. The crust is folded and pushed upwards forming mountains like the Rockies

Old Mountain Ranges The Appalachians are very old, and have smooth, rounded outlines due to the work of glaciers and centuries of weathering and erosion.

Young Mountain Ranges The Rocky Mountains are much younger, and have jagged peaks. This is because the highest points stood above the ice sheets of the last ice age, and they have not been exposed to erosion for the same period of time as the Appalachians.