The cascade volcanoes were formed by the subduction of the Juan De Fuca, Explorer and the Gorda Plate (remnants of the much larger Farallon Plate) under the North American Plate alone the Cascadia subduction zone
Geography can be understood in five different themes. They are:
• Location
• Place
• Human-Environment Interaction (HEI)
• Movement
• Region
This is called species richness