Final answer:
Volcanic hotspots are created when tectonic plates move over stationary areas of heat from the mantle. These hotspots lead to the formation of volcanoes through the melting of the mantle and crust above them.
Step-by-step explanation:
Volcanic hotspots are created when tectonic plates move over stationary areas of heat from the mantle known as hotspots. These hotspots allow extremely hot mantle material to rise close to the surface, resulting in the formation of volcanoes. The melting of the mantle and crust directly above a hotspot leads to the production of volcanic activity.
Hotspots can occur under oceanic crust, producing basalts, or under continental crust, creating both basalts and rhyolites. Examples of hotspots include the Yellowstone hotspot in the United States and the Anahim hotspot in Canada. As the North American Plate moves over these hotspots, calderas form from volcanic activity.
One of the main controversies surrounding hotspots is whether they are still capable of supereruptions or if the volume of eruptive material is diminishing. Hotspots are a geologic phenomenon that is still not fully understood, but their existence and impact on volcanic activity are well-documented.