Final answer:
True, mantle plumes are indeed a critical element in mantle convection within Earth, contributing to tectonic movements and the formation of geological features.
Step-by-step explanation:
True or false: plumes are a critical element in mantle convection within Earth. This statement is true. Mantle plumes are generated at the core-mantle boundary and are regions of increased temperature that can cause the melting of the lithospheric region. These plumes are part of the mantle convection process whereby heat from the interior of Earth causes the upward flow of warmer material and the sinking of cooler material. This convective process is responsible for the movement of tectonic plates and the formation of many geological features, such as hotspot-generated volcanoes, which can be found all over the world.