Q15.Define mantle plume and explain its role in plate tectonics.

A mantle plume is an upwelling of abnormally hot, buoyant rock from deep within the Earth's mantle, often originating near the core-mantle boundary. It rises as a narrow, long-lived conduit with a mushroom-shaped head, stationary relative to tectonic plates.

Mechanisms and Effects

• Hotspot Volcanism: Creates persistent intraplate volcanism (e.g., Hawaii, Yellowstone) as plates move over the stationary plume.
• Continental Rifting: Initiates continental rifting and break-up (e.g., East African Rift) by heating and thinning the lithosphere.
• Large Igneous Provinces (LIPs): Massive plume heads reaching the surface form extensive flood basalts, known as LIPs.
• Mantle Dynamics: Influences mantle convection and may exert minor forces on plate motion.

Mantle plumes are crucial for understanding Earth's internal dynamics, driving significant geological features and crustal evolution independent of plate boundaries.