A Closer Look at 10 Different Types of Valves. A list containing globes, gates, checks, angles and strainers can only mean weâre taking a closer look at different types of valves. In our discussion of the world of maritime supplies, a detailed listing of valves is a necessary procedure. 10 types of valves.
Canadian Shield. The Canadian Shield, also called the Laurentian Plateau, or Bouclier Canadien, is a large area of exposed Precambrian igneous and high-grade metamorphic rocks that forms the ancient geological core of the North American continent, covered by a thin layer of soil.he Canadian Shield, also called the Laurentian Plateau, or Bouclier Canadien, is a large area of exposed Precambrian igneous and high-grade metamorphic rocks that forms the ancient geological core of the North American continent, covered by a thin layer of soil.
The Canadian Shield The Canadian Shield is the principal area of North America where rocks of Precambrian age (i.e., those that are more than 542 million years old) are exposed at the surface. The shield was rifted apart between Canada and Greenland by seafloor spreading in the Labrador Sea and in Baffin Bay between 90 and 40 million years ago.