Answer:
mantle plumes produce volcanoes that do not always coincide with a plate boundary
Explanation:
The mantle plumes are places in the upper mantle that have much higher pressure than the rest of the mantle. Because their pressure is higher, they manage to propel magma through the crust without it depending on a plate boundary. The plate boundaries are places where the magma manages to reach the surface much more easily because of the cracks and spaces, but the mantle plums just don't need that. The magma moves up, melts the rock, lifts up the crust, and creates big and powerful volcanoes.
The volcanoes created by mantle plumes are called hot spot volcanoes. These volcanoes do not necessarily occur where there is a plate boundary, but they can also occur in the middle of a plate. Occasionally, the mantle plumes manage to create volcanic arcs, but that is not always the case.
Examples of such volcanoes are the Hawaiian volcanoes, which are in the Pacific Ocean, and the Yellowstone volcano, which is located on the North American plate.
